diff -ru4NwbB libpng-1.5.6/Makefile.am libpng-1.5.7rc01/Makefile.am --- libpng-1.5.6/Makefile.am 2011-11-02 22:42:58.022435114 -0500 +++ libpng-1.5.7rc01/Makefile.am 2011-12-01 09:01:26.307635096 -0600 @@ -11,15 +11,19 @@ # AUTOMAKE_OPTIONS = foreign color-tests AUTOMAKE_OPTIONS = foreign # test programs - run on make check, make distcheck -check_PROGRAMS= pngtest pngvalid +TESTS_ENVIRONMENT= srcdir=$(srcdir) +check_PROGRAMS= pngtest pngtest_SOURCES = pngtest.c pngtest_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la -pngvalid_SOURCES = pngvalid.c +TESTS = test-pngtest.sh + +# Only do the following if the contrib directory is present. +check_PROGRAMS+= pngvalid +pngvalid_SOURCES = contrib/libtests/pngvalid.c pngvalid_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la -TESTS = test-pngtest.sh test-pngvalid-simple.sh test-pngvalid-full.sh -TESTS_ENVIRONMENT= srcdir=$(srcdir) +TESTS += test-pngvalid-simple.sh test-pngvalid-full.sh # man pages dist_man_MANS= libpng.3 libpngpf.3 png.5 @@ -35,8 +39,12 @@ pngget.c pngmem.c pngpread.c pngread.c pngrio.c pngrtran.c pngrutil.c\ pngset.c pngtrans.c pngwio.c pngwrite.c pngwtran.c pngwutil.c\ png.h pngconf.h pngdebug.h pnginfo.h pngpriv.h pngstruct.h +if PNG_ARM_NEON +libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES += arm/filter_neon.S +endif + nodist_libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES = pnglibconf.h libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_CPPFLAGS = @LIBPNG_DEFINES@ @@ -121,9 +129,9 @@ # The following is necessary to ensure that the local pnglibconf.h is used, not # an installed one (this can happen immediately after on a clean system if # 'make test' is the first thing the user does.) -pngvalid.o pngtest.o: pnglibconf.h +contrib/libtests/pngvalid.o pngtest.o: pnglibconf.h # We must use -DPNG_NO_USE_READ_MACROS here even when the library may actually # be built with PNG_USE_READ_MACROS; this prevents the read macros from # interfering with the symbol file format. @@ -137,19 +145,20 @@ test -d scripts || mkdir scripts echo '#include "$<"' >dfn.c $(DFNCPP) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) @LIBPNG_DEFINES@\ $(CPPFLAGS) $(SYMBOL_CFLAGS) dfn.c > dfn1.out - $(SED) -n -e 's|^.*PNG_DEFN_MAGIC-\(.*\)-PNG_DEFN_END.*$$|\1|p'\ + $(SED) -n -e 's|^.*PNG_DEFN_MAGIC *-\(.*\)- *PNG_DEFN_END.*$$|\1|p'\ dfn1.out >dfn2.out - $(SED) -e 's| *@@@ *||g' -e 's| *$$||' dfn2.out >dfn3.out + $(SED) -e 's| *PNG_JOIN *||g' -e 's| *$$||' dfn2.out >dfn3.out rm -f dfn.c dfn[12].out mv dfn3.out $@ # The .dfn file for pnglibconf.h is machine generated -pnglibconf.dfn: scripts/pnglibconf.dfa scripts/options.awk +pnglibconf.dfn: scripts/pnglibconf.dfa scripts/options.awk pngconf.h rm -f $@ dfn?.out - $(AWK) -f ${srcdir}/scripts/options.awk out=dfn1.out\ - ${srcdir}/scripts/pnglibconf.dfa $(DFA_XTRA) 1>&2 + $(AWK) -f ${srcdir}/scripts/options.awk out=dfn1.out version=search\ + ${srcdir}/pngconf.h ${srcdir}/scripts/pnglibconf.dfa\ + $(DFA_XTRA) 1>&2 $(AWK) -f ${srcdir}/scripts/options.awk out=dfn2.out dfn1.out 1>&2 rm dfn1.out mv dfn2.out $@ @@ -162,14 +171,15 @@ mv symbols.new $@ # used on demand to regenerate the standard header, CPPFLAGS should # be empty - no non-standard defines -scripts/pnglibconf.dfn: scripts/pnglibconf.dfa scripts/options.awk +scripts/pnglibconf.dfn: scripts/pnglibconf.dfa scripts/options.awk pngconf.h rm -f $@ dfn?.out test -z "$(CPPFLAGS)" echo "com @PNGLIB_VERSION@ STANDARD API DEFINITION" |\ - $(AWK) -f ${srcdir}/scripts/options.awk out=dfn1.out\ - logunsupported=1 - ${srcdir}/scripts/pnglibconf.dfa 1>&2 + $(AWK) -f ${srcdir}/scripts/options.awk out=dfn1.out logunsupported=1 + version=search ${srcdir}/pngconf.h -\ + ${srcdir}/scripts/pnglibconf.dfa 1>&2 $(AWK) -f ${srcdir}/scripts/options.awk out=dfn2.out dfn1.out 1>&2 rm dfn1.out mv dfn2.out $@ diff -ru4NwbB libpng-1.5.6/arm/filter_neon.S libpng-1.5.7rc01/arm/filter_neon.S --- libpng-1.5.6/arm/filter_neon.S 1969-12-31 18:00:00.000000000 -0600 +++ libpng-1.5.7rc01/arm/filter_neon.S 2011-11-16 23:02:48.612067000 -0600 @@ -0,0 +1,225 @@ + +/* filter_neon.S - NEON optimised filter functions + * + * Copyright (c) 2011 Glenn Randers-Pehrson + * Written by Mans Rullgard, 2011. + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + */ + +#if defined(__linux__) && defined(__ELF__) +.section .note.GNU-stack,"",%progbits /* mark stack as non-executable */ +#endif + +#ifdef __ELF__ +# define ELF +#else +# define ELF @ +#endif + + .arch armv7-a + .fpu neon + +.macro func name, export=0 + .macro endfunc +ELF .size \name, . - \name + .endfunc + .purgem endfunc + .endm + .text + .if \export + .global \name + .endif +ELF .type \name, STT_FUNC + .func \name +\name: +.endm + +func png_read_filter_row_sub4_neon, export=1 + ldr r3, [r0, #4] @ rowbytes + vmov.i8 d3, #0 +1: + vld4.32 {d4[],d5[],d6[],d7[]}, [r1,:128] + vadd.u8 d0, d3, d4 + vadd.u8 d1, d0, d5 + vadd.u8 d2, d1, d6 + vadd.u8 d3, d2, d7 + vst4.32 {d0[0],d1[0],d2[0],d3[0]},[r1,:128]! + subs r3, r3, #16 + bgt 1b + + bx lr +endfunc + +func png_read_filter_row_sub3_neon, export=1 + ldr r3, [r0, #4] @ rowbytes + vmov.i8 d3, #0 + mov r0, r1 + mov r2, #3 + mov r12, #12 + vld1.8 {q11}, [r0], r12 +1: + vext.8 d5, d22, d23, #3 + vadd.u8 d0, d3, d22 + vext.8 d6, d22, d23, #6 + vadd.u8 d1, d0, d5 + vext.8 d7, d23, d23, #1 + vld1.8 {q11}, [r0], r12 + vst1.32 {d0[0]}, [r1,:32], r2 + vadd.u8 d2, d1, d6 + vst1.32 {d1[0]}, [r1], r2 + vadd.u8 d3, d2, d7 + vst1.32 {d2[0]}, [r1], r2 + vst1.32 {d3[0]}, [r1], r2 + subs r3, r3, #12 + bgt 1b + + bx lr +endfunc + +func png_read_filter_row_up_neon, export=1 + ldr r3, [r0, #4] @ rowbytes +1: + vld1.8 {q0}, [r1,:128] + vld1.8 {q1}, [r2,:128]! + vadd.u8 q0, q0, q1 + vst1.8 {q0}, [r1,:128]! + subs r3, r3, #16 + bgt 1b + + bx lr +endfunc + +func png_read_filter_row_avg4_neon, export=1 + ldr r12, [r0, #4] @ rowbytes + vmov.i8 d3, #0 +1: + vld4.32 {d4[],d5[],d6[],d7[]}, [r1,:128] + vld4.32 {d16[],d17[],d18[],d19[]},[r2,:128]! + vhadd.u8 d0, d3, d16 + vadd.u8 d0, d0, d4 + vhadd.u8 d1, d0, d17 + vadd.u8 d1, d1, d5 + vhadd.u8 d2, d1, d18 + vadd.u8 d2, d2, d6 + vhadd.u8 d3, d2, d19 + vadd.u8 d3, d3, d7 + vst4.32 {d0[0],d1[0],d2[0],d3[0]},[r1,:128]! + subs r12, r12, #16 + bgt 1b + + bx lr +endfunc + +func png_read_filter_row_avg3_neon, export=1 + push {r4,lr} + ldr r12, [r0, #4] @ rowbytes + vmov.i8 d3, #0 + mov r0, r1 + mov r4, #3 + mov lr, #12 + vld1.8 {q11}, [r0], lr +1: + vld1.8 {q10}, [r2], lr + vext.8 d5, d22, d23, #3 + vhadd.u8 d0, d3, d20 + vext.8 d17, d20, d21, #3 + vadd.u8 d0, d0, d22 + vext.8 d6, d22, d23, #6 + vhadd.u8 d1, d0, d17 + vext.8 d18, d20, d21, #6 + vadd.u8 d1, d1, d5 + vext.8 d7, d23, d23, #1 + vld1.8 {q11}, [r0], lr + vst1.32 {d0[0]}, [r1,:32], r4 + vhadd.u8 d2, d1, d18 + vst1.32 {d1[0]}, [r1], r4 + vext.8 d19, d21, d21, #1 + vadd.u8 d2, d2, d6 + vhadd.u8 d3, d2, d19 + vst1.32 {d2[0]}, [r1], r4 + vadd.u8 d3, d3, d7 + vst1.32 {d3[0]}, [r1], r4 + subs r12, r12, #12 + bgt 1b + + pop {r4,pc} +endfunc + +.macro paeth rx, ra, rb, rc + vaddl.u8 q12, \ra, \rb @ a + b + vaddl.u8 q15, \rc, \rc @ 2*c + vabdl.u8 q13, \rb, \rc @ pa + vabdl.u8 q14, \ra, \rc @ pb + vabd.u16 q15, q12, q15 @ pc + vcle.u16 q12, q13, q14 @ pa <= pb + vcle.u16 q13, q13, q15 @ pa <= pc + vcle.u16 q14, q14, q15 @ pb <= pc + vand q12, q12, q13 @ pa <= pb && pa <= pc + vmovn.u16 d28, q14 + vmovn.u16 \rx, q12 + vbsl d28, \rb, \rc + vbsl \rx, \ra, d28 +.endm + +func png_read_filter_row_paeth4_neon, export=1 + ldr r12, [r0, #4] @ rowbytes + vmov.i8 d3, #0 + vmov.i8 d20, #0 +1: + vld4.32 {d4[],d5[],d6[],d7[]}, [r1,:128] + vld4.32 {d16[],d17[],d18[],d19[]},[r2,:128]! + paeth d0, d3, d16, d20 + vadd.u8 d0, d0, d4 + paeth d1, d0, d17, d16 + vadd.u8 d1, d1, d5 + paeth d2, d1, d18, d17 + vadd.u8 d2, d2, d6 + paeth d3, d2, d19, d18 + vmov d20, d19 + vadd.u8 d3, d3, d7 + vst4.32 {d0[0],d1[0],d2[0],d3[0]},[r1,:128]! + subs r12, r12, #16 + bgt 1b + + bx lr +endfunc + +func png_read_filter_row_paeth3_neon, export=1 + push {r4,lr} + ldr r12, [r0, #4] @ rowbytes + vmov.i8 d3, #0 + vmov.i8 d4, #0 + mov r0, r1 + mov r4, #3 + mov lr, #12 + vld1.8 {q11}, [r0], lr +1: + vld1.8 {q10}, [r2], lr + paeth d0, d3, d20, d4 + vext.8 d5, d22, d23, #3 + vadd.u8 d0, d0, d22 + vext.8 d17, d20, d21, #3 + paeth d1, d0, d17, d20 + vst1.32 {d0[0]}, [r1,:32], r4 + vext.8 d6, d22, d23, #6 + vadd.u8 d1, d1, d5 + vext.8 d18, d20, d21, #6 + paeth d2, d1, d18, d17 + vext.8 d7, d23, d23, #1 + vld1.8 {q11}, [r0], lr + vst1.32 {d1[0]}, [r1], r4 + vadd.u8 d2, d2, d6 + vext.8 d19, d21, d21, #1 + paeth d3, d2, d19, d18 + vst1.32 {d2[0]}, [r1], r4 + vmov d4, d19 + vadd.u8 d3, d3, d7 + vst1.32 {d3[0]}, [r1], r4 + subs r12, r12, #12 + bgt 1b + + pop {r4,pc} +endfunc diff -ru4NwbB libpng-1.5.6/configure.ac libpng-1.5.7rc01/configure.ac --- libpng-1.5.6/configure.ac 2011-11-02 22:42:58.029005391 -0500 +++ libpng-1.5.7rc01/configure.ac 2011-12-01 09:01:26.314526184 -0600 @@ -35,8 +35,9 @@ # Checks for programs. AC_LANG([C]) AC_PROG_CC +AM_PROG_AS AC_PROG_LD AC_PROG_CPP AC_CHECK_TOOL(SED, sed, :) AC_CHECK_TOOL(AWK, awk, :) @@ -74,8 +75,9 @@ # Checks for typedefs, structures, and compiler characteristics. AC_C_CONST AC_TYPE_SIZE_T AC_STRUCT_TM +AC_C_RESTRICT # Checks for library functions. AC_FUNC_STRTOD AC_CHECK_FUNCS([memset], , AC_ERROR([memset not found in libc])) @@ -88,8 +90,13 @@ AC_CHECK_LIB(z, zlibVersion, , AC_CHECK_LIB(z, ${ZPREFIX}zlibVersion, , AC_ERROR([zlib not installed]))) +# The following is for pngvalid, to ensure it catches FP errors even on +# platforms that don't enable FP exceptions, the function appears in the math +# library (typically), it's not an error if it is not found. +AC_CHECK_LIB([m], [feenableexcept]) +AC_CHECK_FUNCS([feenableexcept]) LIBPNG_DEFINES=-DPNG_CONFIGURE_LIBPNG LIBPNG_DEFINES=$LIBPNG_DEFINES AC_SUBST(LIBPNG_DEFINES) @@ -176,8 +183,21 @@ fi], [binconfigs='${binconfigs}']) AC_SUBST([binconfigs]) +# Because GCC by default assembles code with an executable stack, even though it +# compiles C code with a non-executable stack, it is necessary to do a fixup +# here (this may by GCC specific) +AC_SUBST([AM_CCASFLAGS], [-Wa,--noexecstack]) + +AC_ARG_ENABLE([arm-neon], + AC_HELP_STRING([--enable-arm-neon], [Enable ARM NEON optimizations]), + [if test "${enableval}" = yes; then + AC_DEFINE([PNG_ARM_NEON], [1], [Enable ARM NEON optimizations]) + AC_DEFINE([PNG_ALIGNED_MEMORY_SUPPORTED], [1], [Align row buffers]) + fi]) +AM_CONDITIONAL([PNG_ARM_NEON], [test "${enable_arm_neon:-no}" = yes]) + # Config files, substituting as above AC_CONFIG_FILES([Makefile libpng.pc:libpng.pc.in]) AC_CONFIG_FILES([libpng-config:libpng-config.in], [chmod +x libpng-config]) diff -ru4NwbB libpng-1.5.6/contrib/README.txt libpng-1.5.7rc01/contrib/README.txt --- libpng-1.5.6/contrib/README.txt 1969-12-31 18:00:00.000000000 -0600 +++ libpng-1.5.7rc01/contrib/README.txt 2011-12-01 09:01:20.934725032 -0600 @@ -0,0 +1,4 @@ + +This "contrib" directory contains contributions which are not necessarily under +the libpng license, although all are open source. They are not part of +libpng proper and are not used for building the library. diff -ru4NwbB libpng-1.5.6/contrib/libtests/pngvalid.c libpng-1.5.7rc01/contrib/libtests/pngvalid.c --- libpng-1.5.6/contrib/libtests/pngvalid.c 1969-12-31 18:00:00.000000000 -0600 +++ libpng-1.5.7rc01/contrib/libtests/pngvalid.c 2011-11-24 11:42:12.755386000 -0600 @@ -0,0 +1,9834 @@ + +/* pngvalid.c - validate libpng by constructing then reading png files. + * + * Last changed in libpng 1.5.7 [(PENDING RELEASE)] + * Copyright (c) 2011 Glenn Randers-Pehrson + * Written by John Cunningham Bowler + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + * + * NOTES: + * This is a C program that is intended to be linked against libpng. It + * generates bitmaps internally, stores them as PNG files (using the + * sequential write code) then reads them back (using the sequential + * read code) and validates that the result has the correct data. + * + * The program can be modified and extended to test the correctness of + * transformations performed by libpng. + */ + +#define _POSIX_SOURCE 1 +#define _ISOC99_SOURCE 1 /* For floating point */ +#define _GNU_SOURCE 1 /* For the floating point exception extension */ + +#include + +#ifdef HAVE_CONFIG_H +# include "config.h" +#endif + +#ifdef HAVE_FEENABLEEXCEPT +# include +#endif + +#include "../../png.h" + +#if PNG_LIBPNG_VER < 10500 +/* This delibarately lacks the PNG_CONST. */ +typedef png_byte *png_const_bytep; + +/* This is copied from 1.5.1 png.h: */ +#define PNG_INTERLACE_ADAM7_PASSES 7 +#define PNG_PASS_START_ROW(pass) (((1U&~(pass))<<(3-((pass)>>1)))&7) +#define PNG_PASS_START_COL(pass) (((1U& (pass))<<(3-(((pass)+1)>>1)))&7) +#define PNG_PASS_ROW_SHIFT(pass) ((pass)>2?(8-(pass))>>1:3) +#define PNG_PASS_COL_SHIFT(pass) ((pass)>1?(7-(pass))>>1:3) +#define PNG_PASS_ROWS(height, pass) (((height)+(((1<>PNG_PASS_ROW_SHIFT(pass)) +#define PNG_PASS_COLS(width, pass) (((width)+(((1<>PNG_PASS_COL_SHIFT(pass)) +#define PNG_ROW_FROM_PASS_ROW(yIn, pass) \ + (((yIn)<>(((7-(off))-(pass))<<2)) & 0xFU) | \ + ((0x01145AF0U>>(((7-(off))-(pass))<<2)) & 0xF0U)) +#define PNG_ROW_IN_INTERLACE_PASS(y, pass) \ + ((PNG_PASS_MASK(pass,0) >> ((y)&7)) & 1) +#define PNG_COL_IN_INTERLACE_PASS(x, pass) \ + ((PNG_PASS_MASK(pass,1) >> ((x)&7)) & 1) + +/* These are needed too for the default build: */ +#define PNG_WRITE_16BIT_SUPPORTED +#define PNG_READ_16BIT_SUPPORTED + +/* This comes from pnglibconf.h afer 1.5: */ +#define PNG_FP_1 100000 +#define PNG_GAMMA_THRESHOLD_FIXED\ + ((png_fixed_point)(PNG_GAMMA_THRESHOLD * PNG_FP_1)) +#endif + +#include "zlib.h" /* For crc32 */ + +#include /* For floating point constants */ +#include /* For malloc */ +#include /* For memcpy, memset */ +#include /* For floor */ + +/* Unused formal parameter errors are removed using the following macro which is + * expected to have no bad effects on performance. + */ +#ifndef UNUSED +# if defined(__GNUC__) || defined(_MSC_VER) +# define UNUSED(param) (void)param; +# else +# define UNUSED(param) +# endif +#endif + +/***************************** EXCEPTION HANDLING *****************************/ +#include "contrib/visupng/cexcept.h" + +#ifdef __cplusplus +# define this not_the_cpp_this +# define new not_the_cpp_new +# define voidcast(type, value) static_cast(value) +#else +# define voidcast(type, value) (value) +#endif /* __cplusplus */ + +struct png_store; +define_exception_type(struct png_store*); + +/* The following are macros to reduce typing everywhere where the well known + * name 'the_exception_context' must be defined. + */ +#define anon_context(ps) struct exception_context *the_exception_context = \ + &(ps)->exception_context +#define context(ps,fault) anon_context(ps); png_store *fault + +/******************************* UTILITIES ************************************/ +/* Error handling is particularly problematic in production code - error + * handlers often themselves have bugs which lead to programs that detect + * minor errors crashing. The following functions deal with one very + * common class of errors in error handlers - attempting to format error or + * warning messages into buffers that are too small. + */ +static size_t safecat(char *buffer, size_t bufsize, size_t pos, + PNG_CONST char *cat) +{ + while (pos < bufsize && cat != NULL && *cat != 0) + buffer[pos++] = *cat++; + + if (pos >= bufsize) + pos = bufsize-1; + + buffer[pos] = 0; + return pos; +} + +static size_t safecatn(char *buffer, size_t bufsize, size_t pos, int n) +{ + char number[64]; + sprintf(number, "%d", n); + return safecat(buffer, bufsize, pos, number); +} + +#ifdef PNG_READ_TRANSFORMS_SUPPORTED +static size_t safecatd(char *buffer, size_t bufsize, size_t pos, double d, + int precision) +{ + char number[64]; + sprintf(number, "%.*f", precision, d); + return safecat(buffer, bufsize, pos, number); +} +#endif + +static PNG_CONST char invalid[] = "invalid"; +static PNG_CONST char sep[] = ": "; + +static PNG_CONST char *colour_types[8] = +{ + "grayscale", invalid, "truecolour", "indexed-colour", + "grayscale with alpha", invalid, "truecolour with alpha", invalid +}; + +/* Convert a double precision value to fixed point. */ +static png_fixed_point +fix(double d) +{ + d = floor(d * PNG_FP_1 + .5); + return (png_fixed_point)d; +} + +/* Generate random bytes. This uses a boring repeatable algorithm and it + * is implemented here so that it gives the same set of numbers on every + * architecture. It's a linear congruential generator (Knuth or Sedgewick + * "Algorithms") but it comes from the 'feedback taps' table in Horowitz and + * Hill, "The Art of Electronics". + */ +static void +make_random_bytes(png_uint_32* seed, void* pv, size_t size) +{ + png_uint_32 u0 = seed[0], u1 = seed[1]; + png_bytep bytes = voidcast(png_bytep, pv); + + /* There are thirty three bits, the next bit in the sequence is bit-33 XOR + * bit-20. The top 1 bit is in u1, the bottom 32 are in u0. + */ + size_t i; + for (i=0; i> (20-8)) ^ ((u1 << 7) | (u0 >> (32-7)))) & 0xff; + u1 <<= 8; + u1 |= u0 >> 24; + u0 <<= 8; + u0 |= u; + *bytes++ = (png_byte)u; + } + + seed[0] = u0; + seed[1] = u1; +} + +static void +make_four_random_bytes(png_uint_32* seed, png_bytep bytes) +{ + make_random_bytes(seed, bytes, 4); +} + +static void +randomize(void *pv, size_t size) +{ + static png_uint_32 random_seed[2] = {0x56789abc, 0xd}; + make_random_bytes(random_seed, pv, size); +} + +#define RANDOMIZE(this) randomize(&(this), sizeof (this)) + +static unsigned int +random_mod(unsigned int max) +{ + unsigned int x; + + RANDOMIZE(x); + + return x % max; /* 0 .. max-1 */ +} + +static int +random_choice(void) +{ + unsigned char x; + + RANDOMIZE(x); + + return x & 1; +} + +/* A numeric ID based on PNG file characteristics. The 'do_interlace' field + * simply records whether pngvalid did the interlace itself or whether it + * was done by libpng. Width and height must be less than 256. 'palette' is an + * index of the palette to use for formats with a palette (0 otherwise.) + */ +#define FILEID(col, depth, palette, interlace, width, height, do_interlace) \ + ((png_uint_32)((col) + ((depth)<<3) + ((palette)<<8) + ((interlace)<<13) + \ + (((do_interlace)!=0)<<15) + ((width)<<16) + ((height)<<24))) + +#define COL_FROM_ID(id) ((png_byte)((id)& 0x7U)) +#define DEPTH_FROM_ID(id) ((png_byte)(((id) >> 3) & 0x1fU)) +#define PALETTE_FROM_ID(id) ((int)(((id) >> 8) & 0x1f)) +#define INTERLACE_FROM_ID(id) ((int)(((id) >> 13) & 0x3)) +#define DO_INTERLACE_FROM_ID(id) ((int)(((id)>>15) & 1)) +#define WIDTH_FROM_ID(id) (((id)>>16) & 0xff) +#define HEIGHT_FROM_ID(id) (((id)>>24) & 0xff) + +/* Utility to construct a standard name for a standard image. */ +static size_t +standard_name(char *buffer, size_t bufsize, size_t pos, png_byte colour_type, + int bit_depth, int npalette, int interlace_type, + png_uint_32 w, png_uint_32 h, int do_interlace) +{ + pos = safecat(buffer, bufsize, pos, colour_types[colour_type]); + if (npalette > 0) + { + pos = safecat(buffer, bufsize, pos, "["); + pos = safecatn(buffer, bufsize, pos, npalette); + pos = safecat(buffer, bufsize, pos, "]"); + } + pos = safecat(buffer, bufsize, pos, " "); + pos = safecatn(buffer, bufsize, pos, bit_depth); + pos = safecat(buffer, bufsize, pos, " bit"); + + if (interlace_type != PNG_INTERLACE_NONE) + { + pos = safecat(buffer, bufsize, pos, " interlaced"); + if (do_interlace) + pos = safecat(buffer, bufsize, pos, "(pngvalid)"); + else + pos = safecat(buffer, bufsize, pos, "(libpng)"); + } + + if (w > 0 || h > 0) + { + pos = safecat(buffer, bufsize, pos, " "); + pos = safecatn(buffer, bufsize, pos, w); + pos = safecat(buffer, bufsize, pos, "x"); + pos = safecatn(buffer, bufsize, pos, h); + } + + return pos; +} + +static size_t +standard_name_from_id(char *buffer, size_t bufsize, size_t pos, png_uint_32 id) +{ + return standard_name(buffer, bufsize, pos, COL_FROM_ID(id), + DEPTH_FROM_ID(id), PALETTE_FROM_ID(id), INTERLACE_FROM_ID(id), + WIDTH_FROM_ID(id), HEIGHT_FROM_ID(id), DO_INTERLACE_FROM_ID(id)); +} + +/* Convenience API and defines to list valid formats. Note that 16 bit read and + * write support is required to do 16 bit read tests (we must be able to make a + * 16 bit image to test!) + */ +#ifdef PNG_WRITE_16BIT_SUPPORTED +# define WRITE_BDHI 4 +# ifdef PNG_READ_16BIT_SUPPORTED +# define READ_BDHI 4 +# define DO_16BIT +# endif +#else +# define WRITE_BDHI 3 +#endif +#ifndef DO_16BIT +# define READ_BDHI 3 +#endif + +/* The following defines the number of different palettes to generate for + * each log bit depth of a colour type 3 standard image. + */ +#define PALETTE_COUNT(bit_depth) ((bit_depth) > 4 ? 1 : 16) + +static int +next_format(png_bytep colour_type, png_bytep bit_depth, int* palette_number) +{ + if (*bit_depth == 0) + { + *colour_type = 0, *bit_depth = 1, *palette_number = 0; + return 1; + } + + if (*colour_type == 3) + { + /* Add multiple palettes for colour type 3. */ + if (++*palette_number < PALETTE_COUNT(*bit_depth)) + return 1; + + *palette_number = 0; + } + + *bit_depth = (png_byte)(*bit_depth << 1); + + /* Palette images are restricted to 8 bit depth */ + if (*bit_depth <= 8 +# ifdef DO_16BIT + || (*colour_type != 3 && *bit_depth <= 16) +# endif + ) + return 1; + + /* Move to the next color type, or return 0 at the end. */ + switch (*colour_type) + { + case 0: + *colour_type = 2; + *bit_depth = 8; + return 1; + + case 2: + *colour_type = 3; + *bit_depth = 1; + return 1; + + case 3: + *colour_type = 4; + *bit_depth = 8; + return 1; + + case 4: + *colour_type = 6; + *bit_depth = 8; + return 1; + + default: + return 0; + } +} + +#ifdef PNG_READ_TRANSFORMS_SUPPORTED +static unsigned int +sample(png_const_bytep row, png_byte colour_type, png_byte bit_depth, + png_uint_32 x, unsigned int sample_index) +{ + png_uint_32 bit_index, result; + + /* Find a sample index for the desired sample: */ + x *= bit_depth; + bit_index = x; + + if ((colour_type & 1) == 0) /* !palette */ + { + if (colour_type & 2) + bit_index *= 3; + + if (colour_type & 4) + bit_index += x; /* Alpha channel */ + + /* Multiple channels; select one: */ + if (colour_type & (2+4)) + bit_index += sample_index * bit_depth; + } + + /* Return the sample from the row as an integer. */ + row += bit_index >> 3; + result = *row; + + if (bit_depth == 8) + return result; + + else if (bit_depth > 8) + return (result << 8) + *++row; + + /* Less than 8 bits per sample. */ + bit_index &= 7; + return (result >> (8-bit_index-bit_depth)) & ((1U<> 3] & ~destMask; + unsigned int sourceByte = fromBuffer[fromIndex >> 3]; + + /* Don't rely on << or >> supporting '0' here, just in case: */ + fromIndex &= 7; + if (fromIndex > 0) sourceByte <<= fromIndex; + if ((toIndex & 7) > 0) sourceByte >>= toIndex & 7; + + toBuffer[toIndex >> 3] = (png_byte)(destByte | (sourceByte & destMask)); + } + else /* One or more bytes */ + memmove(toBuffer+(toIndex>>3), fromBuffer+(fromIndex>>3), pixelSize>>3); +} + +/* Copy a complete row of pixels, taking into account potential partial + * bytes at the end. + */ +static void +row_copy(png_bytep toBuffer, png_const_bytep fromBuffer, unsigned int bitWidth) +{ + memcpy(toBuffer, fromBuffer, bitWidth >> 3); + + if ((bitWidth & 7) != 0) + { + unsigned int mask; + + toBuffer += bitWidth >> 3; + fromBuffer += bitWidth >> 3; + /* The remaining bits are in the top of the byte, the mask is the bits to + * retain. + */ + mask = 0xff >> (bitWidth & 7); + *toBuffer = (png_byte)((*toBuffer & mask) | (*fromBuffer & ~mask)); + } +} + +/* Compare pixels - they are assumed to start at the first byte in the + * given buffers. + */ +static int +pixel_cmp(png_const_bytep pa, png_const_bytep pb, png_uint_32 bit_width) +{ +#if PNG_LIBPNG_VER < 10506 + if (memcmp(pa, pb, bit_width>>3) == 0) + { + png_uint_32 p; + + if ((bit_width & 7) == 0) return 0; + + /* Ok, any differences? */ + p = pa[bit_width >> 3]; + p ^= pb[bit_width >> 3]; + + if (p == 0) return 0; + + /* There are, but they may not be significant, remove the bits + * after the end (the low order bits in PNG.) + */ + bit_width &= 7; + p >>= 8-bit_width; + + if (p == 0) return 0; + } +#else + /* From libpng-1.5.6 the overwrite should be fixed, so compare the trailing + * bits too: + */ + if (memcmp(pa, pb, (bit_width+7)>>3) == 0) + return 0; +#endif + + /* Return the index of the changed byte. */ + { + png_uint_32 where = 0; + + while (pa[where] == pb[where]) ++where; + return 1+where; + } +} + +/*************************** BASIC PNG FILE WRITING ***************************/ +/* A png_store takes data from the sequential writer or provides data + * to the sequential reader. It can also store the result of a PNG + * write for later retrieval. + */ +#define STORE_BUFFER_SIZE 500 /* arbitrary */ +typedef struct png_store_buffer +{ + struct png_store_buffer* prev; /* NOTE: stored in reverse order */ + png_byte buffer[STORE_BUFFER_SIZE]; +} png_store_buffer; + +#define FILE_NAME_SIZE 64 + +typedef struct store_palette_entry /* record of a single palette entry */ +{ + png_byte red; + png_byte green; + png_byte blue; + png_byte alpha; +} store_palette_entry, store_palette[256]; + +typedef struct png_store_file +{ + struct png_store_file* next; /* as many as you like... */ + char name[FILE_NAME_SIZE]; + png_uint_32 id; /* must be correct (see FILEID) */ + png_size_t datacount; /* In this (the last) buffer */ + png_store_buffer data; /* Last buffer in file */ + int npalette; /* Number of entries in palette */ + store_palette_entry* palette; /* May be NULL */ +} png_store_file; + +/* The following is a pool of memory allocated by a single libpng read or write + * operation. + */ +typedef struct store_pool +{ + struct png_store *store; /* Back pointer */ + struct store_memory *list; /* List of allocated memory */ + png_byte mark[4]; /* Before and after data */ + + /* Statistics for this run. */ + png_alloc_size_t max; /* Maximum single allocation */ + png_alloc_size_t current; /* Current allocation */ + png_alloc_size_t limit; /* Highest current allocation */ + png_alloc_size_t total; /* Total allocation */ + + /* Overall statistics (retained across successive runs). */ + png_alloc_size_t max_max; + png_alloc_size_t max_limit; + png_alloc_size_t max_total; +} store_pool; + +typedef struct png_store +{ + /* For cexcept.h exception handling - simply store one of these; + * the context is a self pointer but it may point to a different + * png_store (in fact it never does in this program.) + */ + struct exception_context + exception_context; + + unsigned int verbose :1; + unsigned int treat_warnings_as_errors :1; + unsigned int expect_error :1; + unsigned int expect_warning :1; + unsigned int saw_warning :1; + unsigned int speed :1; + unsigned int progressive :1; /* use progressive read */ + unsigned int validated :1; /* used as a temporary flag */ + int nerrors; + int nwarnings; + char test[128]; /* Name of test */ + char error[256]; + + /* Read fields */ + png_structp pread; /* Used to read a saved file */ + png_infop piread; + png_store_file* current; /* Set when reading */ + png_store_buffer* next; /* Set when reading */ + png_size_t readpos; /* Position in *next */ + png_byte* image; /* Buffer for reading interlaced images */ + png_size_t cb_image; /* Size of this buffer */ + png_size_t cb_row; /* Row size of the image(s) */ + png_uint_32 image_h; /* Number of rows in a single image */ + store_pool read_memory_pool; + + /* Write fields */ + png_store_file* saved; + png_structp pwrite; /* Used when writing a new file */ + png_infop piwrite; + png_size_t writepos; /* Position in .new */ + char wname[FILE_NAME_SIZE]; + png_store_buffer new; /* The end of the new PNG file being written. */ + store_pool write_memory_pool; + store_palette_entry* palette; + int npalette; +} png_store; + +/* Initialization and cleanup */ +static void +store_pool_mark(png_bytep mark) +{ + static png_uint_32 store_seed[2] = { 0x12345678, 1}; + + make_four_random_bytes(store_seed, mark); +} + +/* Use this for random 32 bit values; this function makes sure the result is + * non-zero. + */ +static png_uint_32 +random_32(void) +{ + + for(;;) + { + png_byte mark[4]; + png_uint_32 result; + + store_pool_mark(mark); + result = png_get_uint_32(mark); + + if (result != 0) + return result; + } +} + +static void +store_pool_init(png_store *ps, store_pool *pool) +{ + memset(pool, 0, sizeof *pool); + + pool->store = ps; + pool->list = NULL; + pool->max = pool->current = pool->limit = pool->total = 0; + pool->max_max = pool->max_limit = pool->max_total = 0; + store_pool_mark(pool->mark); +} + +static void +store_init(png_store* ps) +{ + memset(ps, 0, sizeof *ps); + init_exception_context(&ps->exception_context); + store_pool_init(ps, &ps->read_memory_pool); + store_pool_init(ps, &ps->write_memory_pool); + ps->verbose = 0; + ps->treat_warnings_as_errors = 0; + ps->expect_error = 0; + ps->expect_warning = 0; + ps->saw_warning = 0; + ps->speed = 0; + ps->progressive = 0; + ps->validated = 0; + ps->nerrors = ps->nwarnings = 0; + ps->pread = NULL; + ps->piread = NULL; + ps->saved = ps->current = NULL; + ps->next = NULL; + ps->readpos = 0; + ps->image = NULL; + ps->cb_image = 0; + ps->cb_row = 0; + ps->image_h = 0; + ps->pwrite = NULL; + ps->piwrite = NULL; + ps->writepos = 0; + ps->new.prev = NULL; + ps->palette = NULL; + ps->npalette = 0; +} + +static void +store_freebuffer(png_store_buffer* psb) +{ + if (psb->prev) + { + store_freebuffer(psb->prev); + free(psb->prev); + psb->prev = NULL; + } +} + +static void +store_freenew(png_store *ps) +{ + store_freebuffer(&ps->new); + ps->writepos = 0; + if (ps->palette != NULL) + { + free(ps->palette); + ps->palette = NULL; + ps->npalette = 0; + } +} + +static void +store_storenew(png_store *ps) +{ + png_store_buffer *pb; + + if (ps->writepos != STORE_BUFFER_SIZE) + png_error(ps->pwrite, "invalid store call"); + + pb = voidcast(png_store_buffer*, malloc(sizeof *pb)); + + if (pb == NULL) + png_error(ps->pwrite, "store new: OOM"); + + *pb = ps->new; + ps->new.prev = pb; + ps->writepos = 0; +} + +static void +store_freefile(png_store_file **ppf) +{ + if (*ppf != NULL) + { + store_freefile(&(*ppf)->next); + + store_freebuffer(&(*ppf)->data); + (*ppf)->datacount = 0; + if ((*ppf)->palette != NULL) + { + free((*ppf)->palette); + (*ppf)->palette = NULL; + (*ppf)->npalette = 0; + } + free(*ppf); + *ppf = NULL; + } +} + +/* Main interface to file storeage, after writing a new PNG file (see the API + * below) call store_storefile to store the result with the given name and id. + */ +static void +store_storefile(png_store *ps, png_uint_32 id) +{ + png_store_file *pf = voidcast(png_store_file*, malloc(sizeof *pf)); + if (pf == NULL) + png_error(ps->pwrite, "storefile: OOM"); + safecat(pf->name, sizeof pf->name, 0, ps->wname); + pf->id = id; + pf->data = ps->new; + pf->datacount = ps->writepos; + ps->new.prev = NULL; + ps->writepos = 0; + pf->palette = ps->palette; + pf->npalette = ps->npalette; + ps->palette = 0; + ps->npalette = 0; + + /* And save it. */ + pf->next = ps->saved; + ps->saved = pf; +} + +/* Generate an error message (in the given buffer) */ +static size_t +store_message(png_store *ps, png_structp pp, char *buffer, size_t bufsize, + size_t pos, PNG_CONST char *msg) +{ + if (pp != NULL && pp == ps->pread) + { + /* Reading a file */ + pos = safecat(buffer, bufsize, pos, "read: "); + + if (ps->current != NULL) + { + pos = safecat(buffer, bufsize, pos, ps->current->name); + pos = safecat(buffer, bufsize, pos, sep); + } + } + + else if (pp != NULL && pp == ps->pwrite) + { + /* Writing a file */ + pos = safecat(buffer, bufsize, pos, "write: "); + pos = safecat(buffer, bufsize, pos, ps->wname); + pos = safecat(buffer, bufsize, pos, sep); + } + + else + { + /* Neither reading nor writing (or a memory error in struct delete) */ + pos = safecat(buffer, bufsize, pos, "pngvalid: "); + } + + if (ps->test[0] != 0) + { + pos = safecat(buffer, bufsize, pos, ps->test); + pos = safecat(buffer, bufsize, pos, sep); + } + pos = safecat(buffer, bufsize, pos, msg); + return pos; +} + +/* Verbose output to the error stream: */ +static void +store_verbose(png_store *ps, png_structp pp, png_const_charp prefix, + png_const_charp message) +{ + char buffer[512]; + + if (prefix) + fputs(prefix, stderr); + + (void)store_message(ps, pp, buffer, sizeof buffer, 0, message); + fputs(buffer, stderr); + fputc('\n', stderr); +} + +/* Log an error or warning - the relevant count is always incremented. */ +static void +store_log(png_store* ps, png_structp pp, png_const_charp message, int is_error) +{ + /* The warning is copied to the error buffer if there are no errors and it is + * the first warning. The error is copied to the error buffer if it is the + * first error (overwriting any prior warnings). + */ + if (is_error ? (ps->nerrors)++ == 0 : + (ps->nwarnings)++ == 0 && ps->nerrors == 0) + store_message(ps, pp, ps->error, sizeof ps->error, 0, message); + + if (ps->verbose) + store_verbose(ps, pp, is_error ? "error: " : "warning: ", message); +} + +/* Internal error function, called with a png_store but no libpng stuff. */ +static void +internal_error(png_store *ps, png_const_charp message) +{ + store_log(ps, NULL, message, 1 /* error */); + + /* And finally throw an exception. */ + { + struct exception_context *the_exception_context = &ps->exception_context; + Throw ps; + } +} + +/* Functions to use as PNG callbacks. */ +static void +store_error(png_structp pp, png_const_charp message) /* PNG_NORETURN */ +{ + png_store *ps = voidcast(png_store*, png_get_error_ptr(pp)); + + if (!ps->expect_error) + store_log(ps, pp, message, 1 /* error */); + + /* And finally throw an exception. */ + { + struct exception_context *the_exception_context = &ps->exception_context; + Throw ps; + } +} + +static void +store_warning(png_structp pp, png_const_charp message) +{ + png_store *ps = voidcast(png_store*, png_get_error_ptr(pp)); + + if (!ps->expect_warning) + store_log(ps, pp, message, 0 /* warning */); + else + ps->saw_warning = 1; +} + +/* These somewhat odd functions are used when reading an image to ensure that + * the buffer is big enough, the png_structp is for errors. + */ +/* Return a single row from the correct image. */ +static png_bytep +store_image_row(PNG_CONST png_store* ps, png_structp pp, int nImage, + png_uint_32 y) +{ + png_size_t coffset = (nImage * ps->image_h + y) * (ps->cb_row + 5) + 2; + + if (ps->image == NULL) + png_error(pp, "no allocated image"); + + if (coffset + ps->cb_row + 3 > ps->cb_image) + png_error(pp, "image too small"); + + return ps->image + coffset; +} + +static void +store_image_free(png_store *ps, png_structp pp) +{ + if (ps->image != NULL) + { + png_bytep image = ps->image; + + if (image[-1] != 0xed || image[ps->cb_image] != 0xfe) + { + if (pp != NULL) + png_error(pp, "png_store image overwrite (1)"); + else + store_log(ps, NULL, "png_store image overwrite (2)", 1); + } + + ps->image = NULL; + ps->cb_image = 0; + --image; + free(image); + } +} + +static void +store_ensure_image(png_store *ps, png_structp pp, int nImages, png_size_t cbRow, + png_uint_32 cRows) +{ + png_size_t cb = nImages * cRows * (cbRow + 5); + + if (ps->cb_image < cb) + { + png_bytep image; + + store_image_free(ps, pp); + + /* The buffer is deliberately mis-aligned. */ + image = voidcast(png_bytep, malloc(cb+2)); + if (image == NULL) + { + /* Called from the startup - ignore the error for the moment. */ + if (pp == NULL) + return; + + png_error(pp, "OOM allocating image buffer"); + } + + /* These magic tags are used to detect overwrites above. */ + ++image; + image[-1] = 0xed; + image[cb] = 0xfe; + + ps->image = image; + ps->cb_image = cb; + } + + /* We have an adequate sized image; lay out the rows. There are 2 bytes at + * the start and three at the end of each (this ensures that the row + * alignment starts out odd - 2+1 and changes for larger images on each row.) + */ + ps->cb_row = cbRow; + ps->image_h = cRows; + + /* For error checking, the whole buffer is set to 10110010 (0xb2 - 178). + * This deliberately doesn't match the bits in the size test image which are + * outside the image; these are set to 0xff (all 1). To make the row + * comparison work in the 'size' test case the size rows are pre-initialized + * to the same value prior to calling 'standard_row'. + */ + memset(ps->image, 178, cb); + + /* Then put in the marks. */ + while (--nImages >= 0) + { + png_uint_32 y; + + for (y=0; yimage; + + if (image[-1] != 0xed || image[ps->cb_image] != 0xfe) + png_error(pp, "image overwrite"); + else + { + png_size_t cbRow = ps->cb_row; + png_uint_32 rows = ps->image_h; + + image += iImage * (cbRow+5) * ps->image_h; + + image += 2; /* skip image first row markers */ + + while (rows-- > 0) + { + if (image[-2] != 190 || image[-1] != 239) + png_error(pp, "row start overwritten"); + + if (image[cbRow] != 222 || image[cbRow+1] != 173 || + image[cbRow+2] != 17) + png_error(pp, "row end overwritten"); + + image += cbRow+5; + } + } +} + +static void +store_write(png_structp pp, png_bytep pb, png_size_t st) +{ + png_store *ps = voidcast(png_store*, png_get_io_ptr(pp)); + + if (ps->pwrite != pp) + png_error(pp, "store state damaged"); + + while (st > 0) + { + size_t cb; + + if (ps->writepos >= STORE_BUFFER_SIZE) + store_storenew(ps); + + cb = st; + + if (cb > STORE_BUFFER_SIZE - ps->writepos) + cb = STORE_BUFFER_SIZE - ps->writepos; + + memcpy(ps->new.buffer + ps->writepos, pb, cb); + pb += cb; + st -= cb; + ps->writepos += cb; + } +} + +static void +store_flush(png_structp pp) +{ + UNUSED(pp) /*DOES NOTHING*/ +} + +static size_t +store_read_buffer_size(png_store *ps) +{ + /* Return the bytes available for read in the current buffer. */ + if (ps->next != &ps->current->data) + return STORE_BUFFER_SIZE; + + return ps->current->datacount; +} + +#ifdef PNG_READ_TRANSFORMS_SUPPORTED +/* Return total bytes available for read. */ +static size_t +store_read_buffer_avail(png_store *ps) +{ + if (ps->current != NULL && ps->next != NULL) + { + png_store_buffer *next = &ps->current->data; + size_t cbAvail = ps->current->datacount; + + while (next != ps->next && next != NULL) + { + next = next->prev; + cbAvail += STORE_BUFFER_SIZE; + } + + if (next != ps->next) + png_error(ps->pread, "buffer read error"); + + if (cbAvail > ps->readpos) + return cbAvail - ps->readpos; + } + + return 0; +} +#endif + +static int +store_read_buffer_next(png_store *ps) +{ + png_store_buffer *pbOld = ps->next; + png_store_buffer *pbNew = &ps->current->data; + if (pbOld != pbNew) + { + while (pbNew != NULL && pbNew->prev != pbOld) + pbNew = pbNew->prev; + + if (pbNew != NULL) + { + ps->next = pbNew; + ps->readpos = 0; + return 1; + } + + png_error(ps->pread, "buffer lost"); + } + + return 0; /* EOF or error */ +} + +/* Need separate implementation and callback to allow use of the same code + * during progressive read, where the io_ptr is set internally by libpng. + */ +static void +store_read_imp(png_store *ps, png_bytep pb, png_size_t st) +{ + if (ps->current == NULL || ps->next == NULL) + png_error(ps->pread, "store state damaged"); + + while (st > 0) + { + size_t cbAvail = store_read_buffer_size(ps) - ps->readpos; + + if (cbAvail > 0) + { + if (cbAvail > st) cbAvail = st; + memcpy(pb, ps->next->buffer + ps->readpos, cbAvail); + st -= cbAvail; + pb += cbAvail; + ps->readpos += cbAvail; + } + + else if (!store_read_buffer_next(ps)) + png_error(ps->pread, "read beyond end of file"); + } +} + +static void +store_read(png_structp pp, png_bytep pb, png_size_t st) +{ + png_store *ps = voidcast(png_store*, png_get_io_ptr(pp)); + + if (ps == NULL || ps->pread != pp) + png_error(pp, "bad store read call"); + + store_read_imp(ps, pb, st); +} + +static void +store_progressive_read(png_store *ps, png_structp pp, png_infop pi) +{ + /* Notice that a call to store_read will cause this function to fail because + * readpos will be set. + */ + if (ps->pread != pp || ps->current == NULL || ps->next == NULL) + png_error(pp, "store state damaged (progressive)"); + + do + { + if (ps->readpos != 0) + png_error(pp, "store_read called during progressive read"); + + png_process_data(pp, pi, ps->next->buffer, store_read_buffer_size(ps)); + } + while (store_read_buffer_next(ps)); +} + +/* The caller must fill this in: */ +static store_palette_entry * +store_write_palette(png_store *ps, int npalette) +{ + if (ps->pwrite == NULL) + store_log(ps, NULL, "attempt to write palette without write stream", 1); + + if (ps->palette != NULL) + png_error(ps->pwrite, "multiple store_write_palette calls"); + + /* This function can only return NULL if called with '0'! */ + if (npalette > 0) + { + ps->palette = voidcast(store_palette_entry*, malloc(npalette * + sizeof *ps->palette)); + + if (ps->palette == NULL) + png_error(ps->pwrite, "store new palette: OOM"); + + ps->npalette = npalette; + } + + return ps->palette; +} + +static store_palette_entry * +store_current_palette(png_store *ps, int *npalette) +{ + /* This is an internal error (the call has been made outside a read + * operation.) + */ + if (ps->current == NULL) + store_log(ps, ps->pread, "no current stream for palette", 1); + + /* The result may be null if there is no palette. */ + *npalette = ps->current->npalette; + return ps->current->palette; +} + +/***************************** MEMORY MANAGEMENT*** ***************************/ +/* A store_memory is simply the header for an allocated block of memory. The + * pointer returned to libpng is just after the end of the header block, the + * allocated memory is followed by a second copy of the 'mark'. + */ +typedef struct store_memory +{ + store_pool *pool; /* Originating pool */ + struct store_memory *next; /* Singly linked list */ + png_alloc_size_t size; /* Size of memory allocated */ + png_byte mark[4]; /* ID marker */ +} store_memory; + +/* Handle a fatal error in memory allocation. This calls png_error if the + * libpng struct is non-NULL, else it outputs a message and returns. This means + * that a memory problem while libpng is running will abort (png_error) the + * handling of particular file while one in cleanup (after the destroy of the + * struct has returned) will simply keep going and free (or attempt to free) + * all the memory. + */ +static void +store_pool_error(png_store *ps, png_structp pp, PNG_CONST char *msg) +{ + if (pp != NULL) + png_error(pp, msg); + + /* Else we have to do it ourselves. png_error eventually calls store_log, + * above. store_log accepts a NULL png_structp - it just changes what gets + * output by store_message. + */ + store_log(ps, pp, msg, 1 /* error */); +} + +static void +store_memory_free(png_structp pp, store_pool *pool, store_memory *memory) +{ + /* Note that pp may be NULL (see store_pool_delete below), the caller has + * found 'memory' in pool->list *and* unlinked this entry, so this is a valid + * pointer (for sure), but the contents may have been trashed. + */ + if (memory->pool != pool) + store_pool_error(pool->store, pp, "memory corrupted (pool)"); + + else if (memcmp(memory->mark, pool->mark, sizeof memory->mark) != 0) + store_pool_error(pool->store, pp, "memory corrupted (start)"); + + /* It should be safe to read the size field now. */ + else + { + png_alloc_size_t cb = memory->size; + + if (cb > pool->max) + store_pool_error(pool->store, pp, "memory corrupted (size)"); + + else if (memcmp((png_bytep)(memory+1)+cb, pool->mark, sizeof pool->mark) + != 0) + store_pool_error(pool->store, pp, "memory corrupted (end)"); + + /* Finally give the library a chance to find problems too: */ + else + { + pool->current -= cb; + free(memory); + } + } +} + +static void +store_pool_delete(png_store *ps, store_pool *pool) +{ + if (pool->list != NULL) + { + fprintf(stderr, "%s: %s %s: memory lost (list follows):\n", ps->test, + pool == &ps->read_memory_pool ? "read" : "write", + pool == &ps->read_memory_pool ? (ps->current != NULL ? + ps->current->name : "unknown file") : ps->wname); + ++ps->nerrors; + + do + { + store_memory *next = pool->list; + pool->list = next->next; + next->next = NULL; + + fprintf(stderr, "\t%lu bytes @ %p\n", + (unsigned long)next->size, (PNG_CONST void*)(next+1)); + /* The NULL means this will always return, even if the memory is + * corrupted. + */ + store_memory_free(NULL, pool, next); + } + while (pool->list != NULL); + } + + /* And reset the other fields too for the next time. */ + if (pool->max > pool->max_max) pool->max_max = pool->max; + pool->max = 0; + if (pool->current != 0) /* unexpected internal error */ + fprintf(stderr, "%s: %s %s: memory counter mismatch (internal error)\n", + ps->test, pool == &ps->read_memory_pool ? "read" : "write", + pool == &ps->read_memory_pool ? (ps->current != NULL ? + ps->current->name : "unknown file") : ps->wname); + pool->current = 0; + + if (pool->limit > pool->max_limit) + pool->max_limit = pool->limit; + + pool->limit = 0; + + if (pool->total > pool->max_total) + pool->max_total = pool->total; + + pool->total = 0; + + /* Get a new mark too. */ + store_pool_mark(pool->mark); +} + +/* The memory callbacks: */ +static png_voidp +store_malloc(png_structp pp, png_alloc_size_t cb) +{ + store_pool *pool = voidcast(store_pool*, png_get_mem_ptr(pp)); + store_memory *new = voidcast(store_memory*, malloc(cb + (sizeof *new) + + (sizeof pool->mark))); + + if (new != NULL) + { + if (cb > pool->max) + pool->max = cb; + + pool->current += cb; + + if (pool->current > pool->limit) + pool->limit = pool->current; + + pool->total += cb; + + new->size = cb; + memcpy(new->mark, pool->mark, sizeof new->mark); + memcpy((png_byte*)(new+1) + cb, pool->mark, sizeof pool->mark); + new->pool = pool; + new->next = pool->list; + pool->list = new; + ++new; + } + + else + { + /* NOTE: the PNG user malloc function cannot use the png_ptr it is passed + * other than to retrieve the allocation pointer! libpng calls the + * store_malloc callback in two basic cases: + * + * 1) From png_malloc; png_malloc will do a png_error itself if NULL is + * returned. + * 2) From png_struct or png_info structure creation; png_malloc is + * to return so cleanup can be performed. + * + * To handle this store_malloc can log a message, but can't do anything + * else. + */ + store_log(pool->store, pp, "out of memory", 1 /* is_error */); + } + + return new; +} + +static void +store_free(png_structp pp, png_voidp memory) +{ + store_pool *pool = voidcast(store_pool*, png_get_mem_ptr(pp)); + store_memory *this = voidcast(store_memory*, memory), **test; + + /* Because libpng calls store_free with a dummy png_struct when deleting + * png_struct or png_info via png_destroy_struct_2 it is necessary to check + * the passed in png_structp to ensure it is valid, and not pass it to + * png_error if it is not. + */ + if (pp != pool->store->pread && pp != pool->store->pwrite) + pp = NULL; + + /* First check that this 'memory' really is valid memory - it must be in the + * pool list. If it is, use the shared memory_free function to free it. + */ + --this; + for (test = &pool->list; *test != this; test = &(*test)->next) + { + if (*test == NULL) + { + store_pool_error(pool->store, pp, "bad pointer to free"); + return; + } + } + + /* Unlink this entry, *test == this. */ + *test = this->next; + this->next = NULL; + store_memory_free(pp, pool, this); +} + +/* Setup functions. */ +/* Cleanup when aborting a write or after storing the new file. */ +static void +store_write_reset(png_store *ps) +{ + if (ps->pwrite != NULL) + { + anon_context(ps); + + Try + png_destroy_write_struct(&ps->pwrite, &ps->piwrite); + + Catch_anonymous + { + /* memory corruption: continue. */ + } + + ps->pwrite = NULL; + ps->piwrite = NULL; + } + + /* And make sure that all the memory has been freed - this will output + * spurious errors in the case of memory corruption above, but this is safe. + */ + store_pool_delete(ps, &ps->write_memory_pool); + + store_freenew(ps); +} + +/* The following is the main write function, it returns a png_struct and, + * optionally, a png_info suitable for writiing a new PNG file. Use + * store_storefile above to record this file after it has been written. The + * returned libpng structures as destroyed by store_write_reset above. + */ +static png_structp +set_store_for_write(png_store *ps, png_infopp ppi, + PNG_CONST char * volatile name) +{ + anon_context(ps); + + Try + { + if (ps->pwrite != NULL) + png_error(ps->pwrite, "write store already in use"); + + store_write_reset(ps); + safecat(ps->wname, sizeof ps->wname, 0, name); + + /* Don't do the slow memory checks if doing a speed test. */ + if (ps->speed) + ps->pwrite = png_create_write_struct(PNG_LIBPNG_VER_STRING, + ps, store_error, store_warning); + + else + ps->pwrite = png_create_write_struct_2(PNG_LIBPNG_VER_STRING, + ps, store_error, store_warning, &ps->write_memory_pool, + store_malloc, store_free); + + png_set_write_fn(ps->pwrite, ps, store_write, store_flush); + + if (ppi != NULL) + *ppi = ps->piwrite = png_create_info_struct(ps->pwrite); + } + + Catch_anonymous + return NULL; + + return ps->pwrite; +} + +/* Cleanup when finished reading (either due to error or in the success case). + */ +static void +store_read_reset(png_store *ps) +{ + if (ps->pread != NULL) + { + anon_context(ps); + + Try + png_destroy_read_struct(&ps->pread, &ps->piread, NULL); + + Catch_anonymous + { + /* error already output: continue */ + } + + ps->pread = NULL; + ps->piread = NULL; + } + + /* Always do this to be safe. */ + store_pool_delete(ps, &ps->read_memory_pool); + + ps->current = NULL; + ps->next = NULL; + ps->readpos = 0; + ps->validated = 0; +} + +static void +store_read_set(png_store *ps, png_uint_32 id) +{ + png_store_file *pf = ps->saved; + + while (pf != NULL) + { + if (pf->id == id) + { + ps->current = pf; + ps->next = NULL; + store_read_buffer_next(ps); + return; + } + + pf = pf->next; + } + + { + size_t pos; + char msg[FILE_NAME_SIZE+64]; + + pos = standard_name_from_id(msg, sizeof msg, 0, id); + pos = safecat(msg, sizeof msg, pos, ": file not found"); + png_error(ps->pread, msg); + } +} + +/* The main interface for reading a saved file - pass the id number of the file + * to retrieve. Ids must be unique or the earlier file will be hidden. The API + * returns a png_struct and, optionally, a png_info. Both of these will be + * destroyed by store_read_reset above. + */ +static png_structp +set_store_for_read(png_store *ps, png_infopp ppi, png_uint_32 id, + PNG_CONST char *name) +{ + /* Set the name for png_error */ + safecat(ps->test, sizeof ps->test, 0, name); + + if (ps->pread != NULL) + png_error(ps->pread, "read store already in use"); + + store_read_reset(ps); + + /* Both the create APIs can return NULL if used in their default mode + * (because there is no other way of handling an error because the jmp_buf + * by default is stored in png_struct and that has not been allocated!) + * However, given that store_error works correctly in these circumstances + * we don't ever expect NULL in this program. + */ + if (ps->speed) + ps->pread = png_create_read_struct(PNG_LIBPNG_VER_STRING, ps, + store_error, store_warning); + + else + ps->pread = png_create_read_struct_2(PNG_LIBPNG_VER_STRING, ps, + store_error, store_warning, &ps->read_memory_pool, store_malloc, + store_free); + + if (ps->pread == NULL) + { + struct exception_context *the_exception_context = &ps->exception_context; + + store_log(ps, NULL, "png_create_read_struct returned NULL (unexpected)", + 1 /*error*/); + + Throw ps; + } + + store_read_set(ps, id); + + if (ppi != NULL) + *ppi = ps->piread = png_create_info_struct(ps->pread); + + return ps->pread; +} + +/* The overall cleanup of a store simply calls the above then removes all the + * saved files. This does not delete the store itself. + */ +static void +store_delete(png_store *ps) +{ + store_write_reset(ps); + store_read_reset(ps); + store_freefile(&ps->saved); + store_image_free(ps, NULL); +} + +/*********************** PNG FILE MODIFICATION ON READ ************************/ +/* Files may be modified on read. The following structure contains a complete + * png_store together with extra members to handle modification and a special + * read callback for libpng. To use this the 'modifications' field must be set + * to a list of png_modification structures that actually perform the + * modification, otherwise a png_modifier is functionally equivalent to a + * png_store. There is a special read function, set_modifier_for_read, which + * replaces set_store_for_read. + */ +typedef enum modifier_state +{ + modifier_start, /* Initial value */ + modifier_signature, /* Have a signature */ + modifier_IHDR /* Have an IHDR */ +} modifier_state; + +typedef struct CIE_color +{ + /* A single CIE tristimulus value, representing the unique response of a + * standard observer to a variety of light spectra. The observer recognizes + * all spectra that produce this response as the same color, therefore this + * is effectively a description of a color. + */ + double X, Y, Z; +} CIE_color; + +static double +chromaticity_x(CIE_color c) +{ + return c.X / (c.X + c.Y + c.Z); +} + +static double +chromaticity_y(CIE_color c) +{ + return c.Y / (c.X + c.Y + c.Z); +} + +typedef struct color_encoding +{ + /* A description of an (R,G,B) encoding of color (as defined above); this + * includes the actual colors of the (R,G,B) triples (1,0,0), (0,1,0) and + * (0,0,1) plus an encoding value that is used to encode the linear + * components R, G and B to give the actual values R^gamma, G^gamma and + * B^gamma that are stored. + */ + double gamma; /* Encoding (file) gamma of space */ + CIE_color red, green, blue; /* End points */ +} color_encoding; + +static CIE_color +white_point(PNG_CONST color_encoding *encoding) +{ + CIE_color white; + + white.X = encoding->red.X + encoding->green.X + encoding->blue.X; + white.Y = encoding->red.Y + encoding->green.Y + encoding->blue.Y; + white.Z = encoding->red.Z + encoding->green.Z + encoding->blue.Z; + + return white; +} + +static void +normalize_color_encoding(color_encoding *encoding) +{ + PNG_CONST double whiteY = encoding->red.Y + encoding->green.Y + + encoding->blue.Y; + + if (whiteY != 1) + { + encoding->red.X /= whiteY; + encoding->red.Y /= whiteY; + encoding->red.Z /= whiteY; + encoding->green.X /= whiteY; + encoding->green.Y /= whiteY; + encoding->green.Z /= whiteY; + encoding->blue.X /= whiteY; + encoding->blue.Y /= whiteY; + encoding->blue.Z /= whiteY; + } +} + +static size_t +safecat_color_encoding(char *buffer, size_t bufsize, size_t pos, + PNG_CONST color_encoding *e, double encoding_gamma) +{ + if (e != 0) + { + if (encoding_gamma != 0) + pos = safecat(buffer, bufsize, pos, "("); + pos = safecat(buffer, bufsize, pos, "R("); + pos = safecatd(buffer, bufsize, pos, e->red.X, 4); + pos = safecat(buffer, bufsize, pos, ","); + pos = safecatd(buffer, bufsize, pos, e->red.Y, 4); + pos = safecat(buffer, bufsize, pos, ","); + pos = safecatd(buffer, bufsize, pos, e->red.Z, 4); + pos = safecat(buffer, bufsize, pos, "),G("); + pos = safecatd(buffer, bufsize, pos, e->green.X, 4); + pos = safecat(buffer, bufsize, pos, ","); + pos = safecatd(buffer, bufsize, pos, e->green.Y, 4); + pos = safecat(buffer, bufsize, pos, ","); + pos = safecatd(buffer, bufsize, pos, e->green.Z, 4); + pos = safecat(buffer, bufsize, pos, "),B("); + pos = safecatd(buffer, bufsize, pos, e->blue.X, 4); + pos = safecat(buffer, bufsize, pos, ","); + pos = safecatd(buffer, bufsize, pos, e->blue.Y, 4); + pos = safecat(buffer, bufsize, pos, ","); + pos = safecatd(buffer, bufsize, pos, e->blue.Z, 4); + pos = safecat(buffer, bufsize, pos, ")"); + if (encoding_gamma != 0) + pos = safecat(buffer, bufsize, pos, ")"); + } + + if (encoding_gamma != 0) + { + pos = safecat(buffer, bufsize, pos, "^"); + pos = safecatd(buffer, bufsize, pos, encoding_gamma, 5); + } + + return pos; +} + +typedef struct png_modifier +{ + png_store this; /* I am a png_store */ + struct png_modification *modifications; /* Changes to make */ + + modifier_state state; /* My state */ + + /* Information from IHDR: */ + png_byte bit_depth; /* From IHDR */ + png_byte colour_type; /* From IHDR */ + + /* While handling PLTE, IDAT and IEND these chunks may be pended to allow + * other chunks to be inserted. + */ + png_uint_32 pending_len; + png_uint_32 pending_chunk; + + /* Test values */ + double *gammas; + unsigned int ngammas; + unsigned int ngamma_tests; /* Number of gamma tests to run*/ + double current_gamma; /* 0 if not set */ + PNG_CONST color_encoding *encodings; + unsigned int nencodings; + PNG_CONST color_encoding *current_encoding; /* If an encoding has been set */ + unsigned int encoding_counter; /* For iteration */ + int encoding_ignored; /* Something overwrote it */ + + /* Control variables used to iterate through possible encodings, the + * following must be set to 0 and tested by the function that uses the + * png_modifier because the modifier only sets it to 1 (true.) + */ + unsigned int repeat :1; /* Repeat this transform test. */ + unsigned int test_uses_encoding :1; + + /* Lowest sbit to test (libpng fails for sbit < 8) */ + png_byte sbitlow; + + /* Error control - these are the limits on errors accepted by the gamma tests + * below. + */ + double maxout8; /* Maximum output value error */ + double maxabs8; /* Absolute sample error 0..1 */ + double maxcalc8; /* Absolute sample error 0..1 */ + double maxpc8; /* Percentage sample error 0..100% */ + double maxout16; /* Maximum output value error */ + double maxabs16; /* Absolute sample error 0..1 */ + double maxcalc16;/* Absolute sample error 0..1 */ + double maxpc16; /* Percentage sample error 0..100% */ + + /* This is set by transforms that need to allow a higher limit, it is an + * internal check on pngvalid to ensure that the calculated error limits are + * not ridiculous; without this it is too easy to make a mistake in pngvalid + * that allows any value through. + */ + double limit; /* limit on error values, normally 4E-3 */ + + /* Log limits - values above this are logged, but not necessarily + * warned. + */ + double log8; /* Absolute error in 8 bits to log */ + double log16; /* Absolute error in 16 bits to log */ + + /* Logged 8 and 16 bit errors ('output' values): */ + double error_gray_2; + double error_gray_4; + double error_gray_8; + double error_gray_16; + double error_color_8; + double error_color_16; + double error_indexed; + + /* Flags: */ + /* Whether to call png_read_update_info, not png_read_start_image, and how + * many times to call it. + */ + int use_update_info; + + /* Whether or not to interlace. */ + int interlace_type :9; /* int, but must store '1' */ + + /* Run the standard tests? */ + unsigned int test_standard :1; + + /* Run the odd-sized image and interlace read/write tests? */ + unsigned int test_size :1; + + /* Run tests on reading with a combiniation of transforms, */ + unsigned int test_transform :1; + + /* When to use the use_input_precision option: */ + unsigned int use_input_precision :1; + unsigned int use_input_precision_sbit :1; + unsigned int use_input_precision_16to8 :1; + + /* If set assume that the calculation bit depth is set by the input + * precision, not the output precision. + */ + unsigned int calculations_use_input_precision :1; + + /* If set assume that the calculations are done in 16 bits even if both input + * and output are 8 bit or less. + */ + unsigned int assume_16_bit_calculations :1; + + /* Which gamma tests to run: */ + unsigned int test_gamma_threshold :1; + unsigned int test_gamma_transform :1; /* main tests */ + unsigned int test_gamma_sbit :1; + unsigned int test_gamma_scale16 :1; + unsigned int test_gamma_background :1; + unsigned int test_gamma_alpha_mode :1; + unsigned int test_gamma_expand16 :1; + unsigned int test_exhaustive :1; + + unsigned int log :1; /* Log max error */ + + /* Buffer information, the buffer size limits the size of the chunks that can + * be modified - they must fit (including header and CRC) into the buffer! + */ + size_t flush; /* Count of bytes to flush */ + size_t buffer_count; /* Bytes in buffer */ + size_t buffer_position; /* Position in buffer */ + png_byte buffer[1024]; +} png_modifier; + +/* This returns true if the test should be stopped now because it has already + * failed and it is running silently. + */ +static int fail(png_modifier *pm) +{ + return !pm->log && !pm->this.verbose && (pm->this.nerrors > 0 || + (pm->this.treat_warnings_as_errors && pm->this.nwarnings > 0)); +} + +static void +modifier_init(png_modifier *pm) +{ + memset(pm, 0, sizeof *pm); + store_init(&pm->this); + pm->modifications = NULL; + pm->state = modifier_start; + pm->sbitlow = 1U; + pm->ngammas = 0; + pm->ngamma_tests = 0; + pm->gammas = 0; + pm->current_gamma = 0; + pm->encodings = 0; + pm->nencodings = 0; + pm->current_encoding = 0; + pm->encoding_counter = 0; + pm->encoding_ignored = 0; + pm->repeat = 0; + pm->test_uses_encoding = 0; + pm->maxout8 = pm->maxpc8 = pm->maxabs8 = pm->maxcalc8 = 0; + pm->maxout16 = pm->maxpc16 = pm->maxabs16 = pm->maxcalc16 = 0; + pm->limit = 4E-3; + pm->log8 = pm->log16 = 0; /* Means 'off' */ + pm->error_gray_2 = pm->error_gray_4 = pm->error_gray_8 = 0; + pm->error_gray_16 = pm->error_color_8 = pm->error_color_16 = 0; + pm->error_indexed = 0; + pm->use_update_info = 0; + pm->interlace_type = PNG_INTERLACE_NONE; + pm->test_standard = 0; + pm->test_size = 0; + pm->test_transform = 0; + pm->use_input_precision = 0; + pm->use_input_precision_sbit = 0; + pm->use_input_precision_16to8 = 0; + pm->calculations_use_input_precision = 0; + pm->test_gamma_threshold = 0; + pm->test_gamma_transform = 0; + pm->test_gamma_sbit = 0; + pm->test_gamma_scale16 = 0; + pm->test_gamma_background = 0; + pm->test_gamma_alpha_mode = 0; + pm->test_gamma_expand16 = 0; + pm->test_exhaustive = 0; + pm->log = 0; + + /* Rely on the memset for all the other fields - there are no pointers */ +} + +#ifdef PNG_READ_TRANSFORMS_SUPPORTED +/* If pm->calculations_use_input_precision is set then operations will happen + * with only 8 bit precision unless both the input and output bit depth are 16. + * + * If pm->assume_16_bit_calculations is set then even 8 bit calculations use 16 + * bit precision. This only affects those of the following limits that pertain + * to a calculation - not a digitization operation - unless the following API is + * called directly. + */ +static double digitize(PNG_CONST png_modifier *pm, double value, + int sample_depth, int do_round) +{ + /* 'value' is in the range 0 to 1, the result is the same value rounded to a + * multiple of the digitization factor - 8 or 16 bits depending on both the + * sample depth and the 'assume' setting. Digitization is normally by + * rounding and 'do_round' should be 1, if it is 0 the digitized value will + * be truncated. + */ + PNG_CONST unsigned int digitization_factor = + (pm->assume_16_bit_calculations || sample_depth == 16) ? 65535 : 255; + + /* Limiting the range is done as a convenience to the caller - it's easier to + * do it once here than every time at the call site. + */ + if (value <= 0) + value = 0; + else if (value >= 1) + value = 1; + + value *= digitization_factor; + if (do_round) value += .5; + return floor(value)/digitization_factor; +} + +static double abserr(PNG_CONST png_modifier *pm, int in_depth, int out_depth) +{ + /* Absolute error permitted in linear values - affected by the bit depth of + * the calculations. + */ + if (pm->assume_16_bit_calculations || (out_depth == 16 && (in_depth == 16 || + !pm->calculations_use_input_precision))) + return pm->maxabs16; + else + return pm->maxabs8; +} + +static double calcerr(PNG_CONST png_modifier *pm, int in_depth, int out_depth) +{ + /* Error in the linear composition arithmetic - only relevant when + * composition actually happens (0 < alpha < 1). + */ + if (pm->assume_16_bit_calculations || (out_depth == 16 && (in_depth == 16 || + !pm->calculations_use_input_precision))) + return pm->maxcalc16; + else + return pm->maxcalc8; +} + +static double pcerr(PNG_CONST png_modifier *pm, int in_depth, int out_depth) +{ + /* Percentage error permitted in the linear values. Note that the specified + * value is a percentage but this routine returns a simple number. + */ + if (pm->assume_16_bit_calculations || (out_depth == 16 && (in_depth == 16 || + !pm->calculations_use_input_precision))) + return pm->maxpc16 * .01; + else + return pm->maxpc8 * .01; +} + +/* Output error - the error in the encoded value. This is determined by the + * digitization of the output so can be +/-0.5 in the actual output value. In + * the expand_16 case with the current code in libpng the expand happens after + * all the calculations are done in 8 bit arithmetic, so even though the output + * depth is 16 the output error is determined by the 8 bit calculation. + * + * This limit is not determined by the bit depth of internal calculations. + * + * The specified parameter does *not* include the base .5 digitization error but + * it is added here. + */ +static double outerr(PNG_CONST png_modifier *pm, int in_depth, int out_depth) +{ + /* There is a serious error in the 2 and 4 bit grayscale transform because + * the gamma table value (8 bits) is simply shifted, not rounded, so the + * error in 4 bit grayscale gamma is up to the value below. This is a hack + * to allow pngvalid to succeed: + * + * TODO: fix this in libpng + */ + if (out_depth == 2) + return .73182-.5; + + if (out_depth == 4) + return .90644-.5; + + if (out_depth == 16 && (in_depth == 16 || + !pm->calculations_use_input_precision)) + return pm->maxout16; + + /* This is the case where the value was calculated at 8-bit precision then + * scaled to 16 bits. + */ + else if (out_depth == 16) + return pm->maxout8 * 257; + + else + return pm->maxout8; +} + +/* This does the same thing as the above however it returns the value to log, + * rather than raising a warning. This is useful for debugging to track down + * exactly what set of parameters cause high error values. + */ +static double outlog(PNG_CONST png_modifier *pm, int in_depth, int out_depth) +{ + /* The command line parameters are either 8 bit (0..255) or 16 bit (0..65535) + * and so must be adjusted for low bit depth grayscale: + */ + if (out_depth <= 8) + { + if (pm->log8 == 0) /* switched off */ + return 256; + + if (out_depth < 8) + return pm->log8 / 255 * ((1<log8; + } + + if (out_depth == 16 && (in_depth == 16 || + !pm->calculations_use_input_precision)) + { + if (pm->log16 == 0) + return 65536; + + return pm->log16; + } + + /* This is the case where the value was calculated at 8-bit precision then + * scaled to 16 bits. + */ + if (pm->log8 == 0) + return 65536; + + return pm->log8 * 257; +} + +/* This complements the above by providing the appropriate quantization for the + * final value. Normally this would just be quantization to an integral value, + * but in the 8 bit calculation case it's actually quantization to a multiple of + * 257! + */ +static int output_quantization_factor(PNG_CONST png_modifier *pm, int in_depth, + int out_depth) +{ + if (out_depth == 16 && in_depth != 16 + && pm->calculations_use_input_precision) + return 257; + else + return 1; +} + +/* One modification structure must be provided for each chunk to be modified (in + * fact more than one can be provided if multiple separate changes are desired + * for a single chunk.) Modifications include adding a new chunk when a + * suitable chunk does not exist. + * + * The caller of modify_fn will reset the CRC of the chunk and record 'modified' + * or 'added' as appropriate if the modify_fn returns 1 (true). If the + * modify_fn is NULL the chunk is simply removed. + */ +typedef struct png_modification +{ + struct png_modification *next; + png_uint_32 chunk; + + /* If the following is NULL all matching chunks will be removed: */ + int (*modify_fn)(struct png_modifier *pm, + struct png_modification *me, int add); + + /* If the following is set to PLTE, IDAT or IEND and the chunk has not been + * found and modified (and there is a modify_fn) the modify_fn will be called + * to add the chunk before the relevant chunk. + */ + png_uint_32 add; + unsigned int modified :1; /* Chunk was modified */ + unsigned int added :1; /* Chunk was added */ + unsigned int removed :1; /* Chunk was removed */ +} png_modification; + +static void +modification_reset(png_modification *pmm) +{ + if (pmm != NULL) + { + pmm->modified = 0; + pmm->added = 0; + pmm->removed = 0; + modification_reset(pmm->next); + } +} + +static void +modification_init(png_modification *pmm) +{ + memset(pmm, 0, sizeof *pmm); + pmm->next = NULL; + pmm->chunk = 0; + pmm->modify_fn = NULL; + pmm->add = 0; + modification_reset(pmm); +} + +static void +modifier_current_encoding(PNG_CONST png_modifier *pm, color_encoding *ce) +{ + if (pm->current_encoding != 0) + *ce = *pm->current_encoding; + + else + memset(ce, 0, sizeof *ce); + + ce->gamma = pm->current_gamma; +} + +static size_t +safecat_current_encoding(char *buffer, size_t bufsize, size_t pos, + PNG_CONST png_modifier *pm) +{ + pos = safecat_color_encoding(buffer, bufsize, pos, pm->current_encoding, + pm->current_gamma); + + if (pm->encoding_ignored) + pos = safecat(buffer, bufsize, pos, "[overridden]"); + + return pos; +} + +/* Iterate through the usefully testable color encodings. An encoding is one + * of: + * + * 1) Nothing (no color space, no gamma). + * 2) Just a gamma value from the gamma array (including 1.0) + * 3) A color space from the encodings array with the corresponding gamma. + * 4) The same, but with gamma 1.0 (only really useful with 16 bit calculations) + * + * The iterator selects these in turn, the randomizer selects one at random, + * which is used depends on the setting of the 'test_exhaustive' flag. Notice + * that this function changes the colour space encoding so it must only be + * called on completion of the previous test. This is what 'modifier_reset' + * does, below. + * + * After the function has been called the 'repeat' flag will still be set; the + * caller of modifier_reset must reset it at the start of each run of the test! + */ +static unsigned int +modifier_total_encodings(PNG_CONST png_modifier *pm) +{ + return 1 + /* (1) nothing */ + pm->ngammas + /* (2) gamma values to test */ + pm->nencodings + /* (3) total number of encodings */ + /* The following test only works after the first time through the + * png_modifier code because 'bit_depth' is set when the IHDR is read. + * modifier_reset, below, preserves the setting until after it has called + * the iterate function (also below.) + * + * For this reason do not rely on this function outside a call to + * modifier_reset. + */ + ((pm->bit_depth == 16 || pm->assume_16_bit_calculations) ? + pm->nencodings : 0); /* (4) encodings with gamma == 1.0 */ +} + +static void +modifier_encoding_iterate(png_modifier *pm) +{ + if (!pm->repeat && /* Else something needs the current encoding again. */ + pm->test_uses_encoding) /* Some transform is encoding dependent */ + { + if (pm->test_exhaustive) + { + if (++pm->encoding_counter >= modifier_total_encodings(pm)) + pm->encoding_counter = 0; /* This will stop the repeat */ + } + + else + { + /* Not exhaustive - choose an encoding at random; generate a number in + * the range 1..(max-1), so the result is always non-zero: + */ + if (pm->encoding_counter == 0) + pm->encoding_counter = random_mod(modifier_total_encodings(pm)-1)+1; + else + pm->encoding_counter = 0; + } + + if (pm->encoding_counter > 0) + pm->repeat = 1; + } + + else if (!pm->repeat) + pm->encoding_counter = 0; +} + +static void +modifier_reset(png_modifier *pm) +{ + store_read_reset(&pm->this); + pm->limit = 4E-3; + pm->pending_len = pm->pending_chunk = 0; + pm->flush = pm->buffer_count = pm->buffer_position = 0; + pm->modifications = NULL; + pm->state = modifier_start; + modifier_encoding_iterate(pm); + /* The following must be set in the next run. In particular + * test_uses_encodings must be set in the _ini function of each transform + * that looks at the encodings. (Not the 'add' function!) + */ + pm->test_uses_encoding = 0; + pm->current_gamma = 0; + pm->current_encoding = 0; + pm->encoding_ignored = 0; + /* These only become value after IHDR is read: */ + pm->bit_depth = pm->colour_type = 0; +} + +/* The following must be called before anything else to get the encoding set up + * on the modifier. In particular it must be called before the transform init + * functions are called. + */ +static void +modifier_set_encoding(png_modifier *pm) +{ + /* Set the encoding to the one specified by the current encoding counter, + * first clear out all the settings - this corresponds to an encoding_counter + * of 0. + */ + pm->current_gamma = 0; + pm->current_encoding = 0; + pm->encoding_ignored = 0; /* not ignored yet - happens in _ini functions. */ + + /* Now, if required, set the gamma and encoding fields. */ + if (pm->encoding_counter > 0) + { + /* The gammas[] array is an array of screen gammas, not encoding gammas, + * so we need the inverse: + */ + if (pm->encoding_counter <= pm->ngammas) + pm->current_gamma = 1/pm->gammas[pm->encoding_counter-1]; + + else + { + unsigned int i = pm->encoding_counter - pm->ngammas; + + if (i >= pm->nencodings) + { + i %= pm->nencodings; + pm->current_gamma = 1; /* Linear, only in the 16 bit case */ + } + + else + pm->current_gamma = pm->encodings[i].gamma; + + pm->current_encoding = pm->encodings + i; + } + } +} + +/* Enquiry functions to find out what is set. Notice that there is an implicit + * assumption below that the first encoding in the list is the one for sRGB. + */ +static int +modifier_color_encoding_is_sRGB(PNG_CONST png_modifier *pm) +{ + return pm->current_encoding != 0 && pm->current_encoding == pm->encodings && + pm->current_encoding->gamma == pm->current_gamma; +} + +static int +modifier_color_encoding_is_set(PNG_CONST png_modifier *pm) +{ + return pm->current_gamma != 0; +} + +/* Convenience macros. */ +#define CHUNK(a,b,c,d) (((a)<<24)+((b)<<16)+((c)<<8)+(d)) +#define CHUNK_IHDR CHUNK(73,72,68,82) +#define CHUNK_PLTE CHUNK(80,76,84,69) +#define CHUNK_IDAT CHUNK(73,68,65,84) +#define CHUNK_IEND CHUNK(73,69,78,68) +#define CHUNK_cHRM CHUNK(99,72,82,77) +#define CHUNK_gAMA CHUNK(103,65,77,65) +#define CHUNK_sBIT CHUNK(115,66,73,84) +#define CHUNK_sRGB CHUNK(115,82,71,66) + +/* The guts of modification are performed during a read. */ +static void +modifier_crc(png_bytep buffer) +{ + /* Recalculate the chunk CRC - a complete chunk must be in + * the buffer, at the start. + */ + uInt datalen = png_get_uint_32(buffer); + uLong crc = crc32(0, buffer+4, datalen+4); + /* The cast to png_uint_32 is safe because a crc32 is always a 32 bit value. + */ + png_save_uint_32(buffer+datalen+8, (png_uint_32)crc); +} + +static void +modifier_setbuffer(png_modifier *pm) +{ + modifier_crc(pm->buffer); + pm->buffer_count = png_get_uint_32(pm->buffer)+12; + pm->buffer_position = 0; +} + +/* Separate the callback into the actual implementation (which is passed the + * png_modifier explicitly) and the callback, which gets the modifier from the + * png_struct. + */ +static void +modifier_read_imp(png_modifier *pm, png_bytep pb, png_size_t st) +{ + while (st > 0) + { + size_t cb; + png_uint_32 len, chunk; + png_modification *mod; + + if (pm->buffer_position >= pm->buffer_count) switch (pm->state) + { + static png_byte sign[8] = { 137, 80, 78, 71, 13, 10, 26, 10 }; + case modifier_start: + store_read_imp(&pm->this, pm->buffer, 8); /* size of signature. */ + pm->buffer_count = 8; + pm->buffer_position = 0; + + if (memcmp(pm->buffer, sign, 8) != 0) + png_error(pm->this.pread, "invalid PNG file signature"); + pm->state = modifier_signature; + break; + + case modifier_signature: + store_read_imp(&pm->this, pm->buffer, 13+12); /* size of IHDR */ + pm->buffer_count = 13+12; + pm->buffer_position = 0; + + if (png_get_uint_32(pm->buffer) != 13 || + png_get_uint_32(pm->buffer+4) != CHUNK_IHDR) + png_error(pm->this.pread, "invalid IHDR"); + + /* Check the list of modifiers for modifications to the IHDR. */ + mod = pm->modifications; + while (mod != NULL) + { + if (mod->chunk == CHUNK_IHDR && mod->modify_fn && + (*mod->modify_fn)(pm, mod, 0)) + { + mod->modified = 1; + modifier_setbuffer(pm); + } + + /* Ignore removal or add if IHDR! */ + mod = mod->next; + } + + /* Cache information from the IHDR (the modified one.) */ + pm->bit_depth = pm->buffer[8+8]; + pm->colour_type = pm->buffer[8+8+1]; + + pm->state = modifier_IHDR; + pm->flush = 0; + break; + + case modifier_IHDR: + default: + /* Read a new chunk and process it until we see PLTE, IDAT or + * IEND. 'flush' indicates that there is still some data to + * output from the preceding chunk. + */ + if ((cb = pm->flush) > 0) + { + if (cb > st) cb = st; + pm->flush -= cb; + store_read_imp(&pm->this, pb, cb); + pb += cb; + st -= cb; + if (st == 0) return; + } + + /* No more bytes to flush, read a header, or handle a pending + * chunk. + */ + if (pm->pending_chunk != 0) + { + png_save_uint_32(pm->buffer, pm->pending_len); + png_save_uint_32(pm->buffer+4, pm->pending_chunk); + pm->pending_len = 0; + pm->pending_chunk = 0; + } + else + store_read_imp(&pm->this, pm->buffer, 8); + + pm->buffer_count = 8; + pm->buffer_position = 0; + + /* Check for something to modify or a terminator chunk. */ + len = png_get_uint_32(pm->buffer); + chunk = png_get_uint_32(pm->buffer+4); + + /* Terminators first, they may have to be delayed for added + * chunks + */ + if (chunk == CHUNK_PLTE || chunk == CHUNK_IDAT || + chunk == CHUNK_IEND) + { + mod = pm->modifications; + + while (mod != NULL) + { + if ((mod->add == chunk || + (mod->add == CHUNK_PLTE && chunk == CHUNK_IDAT)) && + mod->modify_fn != NULL && !mod->modified && !mod->added) + { + /* Regardless of what the modify function does do not run + * this again. + */ + mod->added = 1; + + if ((*mod->modify_fn)(pm, mod, 1 /*add*/)) + { + /* Reset the CRC on a new chunk */ + if (pm->buffer_count > 0) + modifier_setbuffer(pm); + + else + { + pm->buffer_position = 0; + mod->removed = 1; + } + + /* The buffer has been filled with something (we assume) + * so output this. Pend the current chunk. + */ + pm->pending_len = len; + pm->pending_chunk = chunk; + break; /* out of while */ + } + } + + mod = mod->next; + } + + /* Don't do any further processing if the buffer was modified - + * otherwise the code will end up modifying a chunk that was + * just added. + */ + if (mod != NULL) + break; /* out of switch */ + } + + /* If we get to here then this chunk may need to be modified. To + * do this it must be less than 1024 bytes in total size, otherwise + * it just gets flushed. + */ + if (len+12 <= sizeof pm->buffer) + { + store_read_imp(&pm->this, pm->buffer+pm->buffer_count, + len+12-pm->buffer_count); + pm->buffer_count = len+12; + + /* Check for a modification, else leave it be. */ + mod = pm->modifications; + while (mod != NULL) + { + if (mod->chunk == chunk) + { + if (mod->modify_fn == NULL) + { + /* Remove this chunk */ + pm->buffer_count = pm->buffer_position = 0; + mod->removed = 1; + break; /* Terminate the while loop */ + } + + else if ((*mod->modify_fn)(pm, mod, 0)) + { + mod->modified = 1; + /* The chunk may have been removed: */ + if (pm->buffer_count == 0) + { + pm->buffer_position = 0; + break; + } + modifier_setbuffer(pm); + } + } + + mod = mod->next; + } + } + + else + pm->flush = len+12 - pm->buffer_count; /* data + crc */ + + /* Take the data from the buffer (if there is any). */ + break; + } + + /* Here to read from the modifier buffer (not directly from + * the store, as in the flush case above.) + */ + cb = pm->buffer_count - pm->buffer_position; + + if (cb > st) + cb = st; + + memcpy(pb, pm->buffer + pm->buffer_position, cb); + st -= cb; + pb += cb; + pm->buffer_position += cb; + } +} + +/* The callback: */ +static void +modifier_read(png_structp pp, png_bytep pb, png_size_t st) +{ + png_modifier *pm = voidcast(png_modifier*, png_get_io_ptr(pp)); + + if (pm == NULL || pm->this.pread != pp) + png_error(pp, "bad modifier_read call"); + + modifier_read_imp(pm, pb, st); +} + +/* Like store_progressive_read but the data is getting changed as we go so we + * need a local buffer. + */ +static void +modifier_progressive_read(png_modifier *pm, png_structp pp, png_infop pi) +{ + if (pm->this.pread != pp || pm->this.current == NULL || + pm->this.next == NULL) + png_error(pp, "store state damaged (progressive)"); + + /* This is another Horowitz and Hill random noise generator. In this case + * the aim is to stress the progressive reader with truly horrible variable + * buffer sizes in the range 1..500, so a sequence of 9 bit random numbers + * is generated. We could probably just count from 1 to 32767 and get as + * good a result. + */ + for (;;) + { + static png_uint_32 noise = 1; + png_size_t cb, cbAvail; + png_byte buffer[512]; + + /* Generate 15 more bits of stuff: */ + noise = (noise << 9) | ((noise ^ (noise >> (9-5))) & 0x1ff); + cb = noise & 0x1ff; + + /* Check that this number of bytes are available (in the current buffer.) + * (This doesn't quite work - the modifier might delete a chunk; unlikely + * but possible, it doesn't happen at present because the modifier only + * adds chunks to standard images.) + */ + cbAvail = store_read_buffer_avail(&pm->this); + if (pm->buffer_count > pm->buffer_position) + cbAvail += pm->buffer_count - pm->buffer_position; + + if (cb > cbAvail) + { + /* Check for EOF: */ + if (cbAvail == 0) + break; + + cb = cbAvail; + } + + modifier_read_imp(pm, buffer, cb); + png_process_data(pp, pi, buffer, cb); + } + + /* Check the invariants at the end (if this fails it's a problem in this + * file!) + */ + if (pm->buffer_count > pm->buffer_position || + pm->this.next != &pm->this.current->data || + pm->this.readpos < pm->this.current->datacount) + png_error(pp, "progressive read implementation error"); +} + +/* Set up a modifier. */ +static png_structp +set_modifier_for_read(png_modifier *pm, png_infopp ppi, png_uint_32 id, + PNG_CONST char *name) +{ + /* Do this first so that the modifier fields are cleared even if an error + * happens allocating the png_struct. No allocation is done here so no + * cleanup is required. + */ + pm->state = modifier_start; + pm->bit_depth = 0; + pm->colour_type = 255; + + pm->pending_len = 0; + pm->pending_chunk = 0; + pm->flush = 0; + pm->buffer_count = 0; + pm->buffer_position = 0; + + return set_store_for_read(&pm->this, ppi, id, name); +} + + +/******************************** MODIFICATIONS *******************************/ +/* Standard modifications to add chunks. These do not require the _SUPPORTED + * macros because the chunks can be there regardless of whether this specific + * libpng supports them. + */ +typedef struct gama_modification +{ + png_modification this; + png_fixed_point gamma; +} gama_modification; + +static int +gama_modify(png_modifier *pm, png_modification *me, int add) +{ + UNUSED(add) + /* This simply dumps the given gamma value into the buffer. */ + png_save_uint_32(pm->buffer, 4); + png_save_uint_32(pm->buffer+4, CHUNK_gAMA); + png_save_uint_32(pm->buffer+8, ((gama_modification*)me)->gamma); + return 1; +} + +static void +gama_modification_init(gama_modification *me, png_modifier *pm, double gammad) +{ + double g; + + modification_init(&me->this); + me->this.chunk = CHUNK_gAMA; + me->this.modify_fn = gama_modify; + me->this.add = CHUNK_PLTE; + g = fix(gammad); + me->gamma = (png_fixed_point)g; + me->this.next = pm->modifications; + pm->modifications = &me->this; +} + +typedef struct chrm_modification +{ + png_modification this; + PNG_CONST color_encoding *encoding; + png_fixed_point wx, wy, rx, ry, gx, gy, bx, by; +} chrm_modification; + +static int +chrm_modify(png_modifier *pm, png_modification *me, int add) +{ + UNUSED(add) + /* As with gAMA this just adds the required cHRM chunk to the buffer. */ + png_save_uint_32(pm->buffer , 32); + png_save_uint_32(pm->buffer+ 4, CHUNK_cHRM); + png_save_uint_32(pm->buffer+ 8, ((chrm_modification*)me)->wx); + png_save_uint_32(pm->buffer+12, ((chrm_modification*)me)->wy); + png_save_uint_32(pm->buffer+16, ((chrm_modification*)me)->rx); + png_save_uint_32(pm->buffer+20, ((chrm_modification*)me)->ry); + png_save_uint_32(pm->buffer+24, ((chrm_modification*)me)->gx); + png_save_uint_32(pm->buffer+28, ((chrm_modification*)me)->gy); + png_save_uint_32(pm->buffer+32, ((chrm_modification*)me)->bx); + png_save_uint_32(pm->buffer+36, ((chrm_modification*)me)->by); + return 1; +} + +static void +chrm_modification_init(chrm_modification *me, png_modifier *pm, + PNG_CONST color_encoding *encoding) +{ + CIE_color white = white_point(encoding); + + /* Original end points: */ + me->encoding = encoding; + + /* Chromaticities (in fixed point): */ + me->wx = fix(chromaticity_x(white)); + me->wy = fix(chromaticity_y(white)); + + me->rx = fix(chromaticity_x(encoding->red)); + me->ry = fix(chromaticity_y(encoding->red)); + me->gx = fix(chromaticity_x(encoding->green)); + me->gy = fix(chromaticity_y(encoding->green)); + me->bx = fix(chromaticity_x(encoding->blue)); + me->by = fix(chromaticity_y(encoding->blue)); + + modification_init(&me->this); + me->this.chunk = CHUNK_cHRM; + me->this.modify_fn = chrm_modify; + me->this.add = CHUNK_PLTE; + me->this.next = pm->modifications; + pm->modifications = &me->this; +} + +typedef struct srgb_modification +{ + png_modification this; + png_byte intent; +} srgb_modification; + +static int +srgb_modify(png_modifier *pm, png_modification *me, int add) +{ + UNUSED(add) + /* As above, ignore add and just make a new chunk */ + png_save_uint_32(pm->buffer, 1); + png_save_uint_32(pm->buffer+4, CHUNK_sRGB); + pm->buffer[8] = ((srgb_modification*)me)->intent; + return 1; +} + +static void +srgb_modification_init(srgb_modification *me, png_modifier *pm, png_byte intent) +{ + modification_init(&me->this); + me->this.chunk = CHUNK_sBIT; + + if (intent <= 3) /* if valid, else *delete* sRGB chunks */ + { + me->this.modify_fn = srgb_modify; + me->this.add = CHUNK_PLTE; + me->intent = intent; + } + + else + { + me->this.modify_fn = 0; + me->this.add = 0; + me->intent = 0; + } + + me->this.next = pm->modifications; + pm->modifications = &me->this; +} + +typedef struct sbit_modification +{ + png_modification this; + png_byte sbit; +} sbit_modification; + +static int +sbit_modify(png_modifier *pm, png_modification *me, int add) +{ + png_byte sbit = ((sbit_modification*)me)->sbit; + if (pm->bit_depth > sbit) + { + int cb = 0; + switch (pm->colour_type) + { + case 0: + cb = 1; + break; + + case 2: + case 3: + cb = 3; + break; + + case 4: + cb = 2; + break; + + case 6: + cb = 4; + break; + + default: + png_error(pm->this.pread, + "unexpected colour type in sBIT modification"); + } + + png_save_uint_32(pm->buffer, cb); + png_save_uint_32(pm->buffer+4, CHUNK_sBIT); + + while (cb > 0) + (pm->buffer+8)[--cb] = sbit; + + return 1; + } + else if (!add) + { + /* Remove the sBIT chunk */ + pm->buffer_count = pm->buffer_position = 0; + return 1; + } + else + return 0; /* do nothing */ +} + +static void +sbit_modification_init(sbit_modification *me, png_modifier *pm, png_byte sbit) +{ + modification_init(&me->this); + me->this.chunk = CHUNK_sBIT; + me->this.modify_fn = sbit_modify; + me->this.add = CHUNK_PLTE; + me->sbit = sbit; + me->this.next = pm->modifications; + pm->modifications = &me->this; +} +#endif /* PNG_READ_TRANSFORMS_SUPPORTED */ + +/***************************** STANDARD PNG FILES *****************************/ +/* Standard files - write and save standard files. */ +/* There are two basic forms of standard images. Those which attempt to have + * all the possible pixel values (not possible for 16bpp images, but a range of + * values are produced) and those which have a range of image sizes. The former + * are used for testing transforms, in particular gamma correction and bit + * reduction and increase. The latter are reserved for testing the behavior of + * libpng with respect to 'odd' image sizes - particularly small images where + * rows become 1 byte and interlace passes disappear. + * + * The first, most useful, set are the 'transform' images, the second set of + * small images are the 'size' images. + * + * The transform files are constructed with rows which fit into a 1024 byte row + * buffer. This makes allocation easier below. Further regardless of the file + * format every row has 128 pixels (giving 1024 bytes for 64bpp formats). + * + * Files are stored with no gAMA or sBIT chunks, with a PLTE only when needed + * and with an ID derived from the colour type, bit depth and interlace type + * as above (FILEID). The width (128) and height (variable) are not stored in + * the FILEID - instead the fields are set to 0, indicating a transform file. + * + * The size files ar constructed with rows a maximum of 128 bytes wide, allowing + * a maximum width of 16 pixels (for the 64bpp case.) They also have a maximum + * height of 16 rows. The width and height are stored in the FILEID and, being + * non-zero, indicate a size file. + * + * For palette image (colour type 3) multiple transform images are stored with + * the same bit depth to allow testing of more colour combinations - + * particularly important for testing the gamma code because libpng uses a + * different code path for palette images. For size images a single palette is + * used. + */ + +/* Make a 'standard' palette. Because there are only 256 entries in a palette + * (maximum) this actually makes a random palette in the hope that enough tests + * will catch enough errors. (Note that the same palette isn't produced every + * time for the same test - it depends on what previous tests have been run - + * but a given set of arguments to pngvalid will always produce the same palette + * at the same test! This is why pseudo-random number generators are useful for + * testing.) + * + * The store must be open for write when this is called, otherwise an internal + * error will occur. This routine contains its own magic number seed, so the + * palettes generated don't change if there are intervening errors (changing the + * calls to the store_mark seed.) + */ +static store_palette_entry * +make_standard_palette(png_store* ps, int npalette, int do_tRNS) +{ + static png_uint_32 palette_seed[2] = { 0x87654321, 9 }; + + int i = 0; + png_byte values[256][4]; + + /* Always put in black and white plus the six primary and secondary colors. + */ + for (; i<8; ++i) + { + values[i][1] = (i&1) ? 255 : 0; + values[i][2] = (i&2) ? 255 : 0; + values[i][3] = (i&4) ? 255 : 0; + } + + /* Then add 62 grays (one quarter of the remaining 256 slots). */ + { + int j = 0; + png_byte random_bytes[4]; + png_byte need[256]; + + need[0] = 0; /*got black*/ + memset(need+1, 1, (sizeof need)-2); /*need these*/ + need[255] = 0; /*but not white*/ + + while (i<70) + { + png_byte b; + + if (j==0) + { + make_four_random_bytes(palette_seed, random_bytes); + j = 4; + } + + b = random_bytes[--j]; + if (need[b]) + { + values[i][1] = b; + values[i][2] = b; + values[i++][3] = b; + } + } + } + + /* Finally add 192 colors at random - don't worry about matches to things we + * already have, chance is less than 1/65536. Don't worry about grays, + * chance is the same, so we get a duplicate or extra gray less than 1 time + * in 170. + */ + for (; i<256; ++i) + make_four_random_bytes(palette_seed, values[i]); + + /* Fill in the alpha values in the first byte. Just use all possible values + * (0..255) in an apparently random order: + */ + { + store_palette_entry *palette; + png_byte selector[4]; + + make_four_random_bytes(palette_seed, selector); + + if (do_tRNS) + for (i=0; i<256; ++i) + values[i][0] = (png_byte)(i ^ selector[0]); + + else + for (i=0; i<256; ++i) + values[i][0] = 255; /* no transparency/tRNS chunk */ + + /* 'values' contains 256 ARGB values, but we only need 'npalette'. + * 'npalette' will always be a power of 2: 2, 4, 16 or 256. In the low + * bit depth cases select colors at random, else it is difficult to have + * a set of low bit depth palette test with any chance of a reasonable + * range of colors. Do this by randomly permuting values into the low + * 'npalette' entries using an XOR mask generated here. This also + * permutes the npalette == 256 case in a potentially useful way (there is + * no relationship between palette index and the color value therein!) + */ + palette = store_write_palette(ps, npalette); + + for (i=0; i 0) + png_set_tRNS(pp, pi, tRNS, j, 0/*color*/); + } +} + +/* The number of passes is related to the interlace type. There was no libpng + * API to determine this prior to 1.5, so we need an inquiry function: + */ +static int +npasses_from_interlace_type(png_structp pp, int interlace_type) +{ + switch (interlace_type) + { + default: + png_error(pp, "invalid interlace type"); + + case PNG_INTERLACE_NONE: + return 1; + + case PNG_INTERLACE_ADAM7: + return PNG_INTERLACE_ADAM7_PASSES; + } +} + +static unsigned int +bit_size(png_structp pp, png_byte colour_type, png_byte bit_depth) +{ + switch (colour_type) + { + default: png_error(pp, "invalid color type"); + + case 0: return bit_depth; + + case 2: return 3*bit_depth; + + case 3: return bit_depth; + + case 4: return 2*bit_depth; + + case 6: return 4*bit_depth; + } +} + +#define TRANSFORM_WIDTH 128U +#define TRANSFORM_ROWMAX (TRANSFORM_WIDTH*8U) +#define SIZE_ROWMAX (16*8U) /* 16 pixels, max 8 bytes each - 128 bytes */ +#define STANDARD_ROWMAX TRANSFORM_ROWMAX /* The larger of the two */ +#define SIZE_HEIGHTMAX 16 /* Maximum range of size images */ + +static size_t +transform_rowsize(png_structp pp, png_byte colour_type, png_byte bit_depth) +{ + return (TRANSFORM_WIDTH * bit_size(pp, colour_type, bit_depth)) / 8; +} + +/* transform_width(pp, colour_type, bit_depth) current returns the same number + * every time, so just use a macro: + */ +#define transform_width(pp, colour_type, bit_depth) TRANSFORM_WIDTH + +static png_uint_32 +transform_height(png_structp pp, png_byte colour_type, png_byte bit_depth) +{ + switch (bit_size(pp, colour_type, bit_depth)) + { + case 1: + case 2: + case 4: + return 1; /* Total of 128 pixels */ + + case 8: + return 2; /* Total of 256 pixels/bytes */ + + case 16: + return 512; /* Total of 65536 pixels */ + + case 24: + case 32: + return 512; /* 65536 pixels */ + + case 48: + case 64: + return 2048;/* 4 x 65536 pixels. */ +# define TRANSFORM_HEIGHTMAX 2048 + + default: + return 0; /* Error, will be caught later */ + } +} + +/* The following can only be defined here, now we have the definitions + * of the transform image sizes. + */ +static png_uint_32 +standard_width(png_structp pp, png_uint_32 id) +{ + png_uint_32 width = WIDTH_FROM_ID(id); + UNUSED(pp) + + if (width == 0) + width = transform_width(pp, COL_FROM_ID(id), DEPTH_FROM_ID(id)); + + return width; +} + +static png_uint_32 +standard_height(png_structp pp, png_uint_32 id) +{ + png_uint_32 height = HEIGHT_FROM_ID(id); + + if (height == 0) + height = transform_height(pp, COL_FROM_ID(id), DEPTH_FROM_ID(id)); + + return height; +} + +static png_uint_32 +standard_rowsize(png_structp pp, png_uint_32 id) +{ + png_uint_32 width = standard_width(pp, id); + + /* This won't overflow: */ + width *= bit_size(pp, COL_FROM_ID(id), DEPTH_FROM_ID(id)); + return (width + 7) / 8; +} + +static void +transform_row(png_structp pp, png_byte buffer[TRANSFORM_ROWMAX], + png_byte colour_type, png_byte bit_depth, png_uint_32 y) +{ + png_uint_32 v = y << 7; + png_uint_32 i = 0; + + switch (bit_size(pp, colour_type, bit_depth)) + { + case 1: + while (i<128/8) buffer[i] = v & 0xff, v += 17, ++i; + return; + + case 2: + while (i<128/4) buffer[i] = v & 0xff, v += 33, ++i; + return; + + case 4: + while (i<128/2) buffer[i] = v & 0xff, v += 65, ++i; + return; + + case 8: + /* 256 bytes total, 128 bytes in each row set as follows: */ + while (i<128) buffer[i] = v & 0xff, ++v, ++i; + return; + + case 16: + /* Generate all 65536 pixel values in order, which includes the 8 bit + * GA case as well as the 16 bit G case. + */ + while (i<128) + buffer[2*i] = (v>>8) & 0xff, buffer[2*i+1] = v & 0xff, ++v, ++i; + + return; + + case 24: + /* 65535 pixels, but rotate the values. */ + while (i<128) + { + /* Three bytes per pixel, r, g, b, make b by r^g */ + buffer[3*i+0] = (v >> 8) & 0xff; + buffer[3*i+1] = v & 0xff; + buffer[3*i+2] = ((v >> 8) ^ v) & 0xff; + ++v; + ++i; + } + + return; + + case 32: + /* 65535 pixels, r, g, b, a; just replicate */ + while (i<128) + { + buffer[4*i+0] = (v >> 8) & 0xff; + buffer[4*i+1] = v & 0xff; + buffer[4*i+2] = (v >> 8) & 0xff; + buffer[4*i+3] = v & 0xff; + ++v; + ++i; + } + + return; + + case 48: + /* y is maximum 2047, giving 4x65536 pixels, make 'r' increase by 1 at + * each pixel, g increase by 257 (0x101) and 'b' by 0x1111: + */ + while (i<128) + { + png_uint_32 t = v++; + buffer[6*i+0] = (t >> 8) & 0xff; + buffer[6*i+1] = t & 0xff; + t *= 257; + buffer[6*i+2] = (t >> 8) & 0xff; + buffer[6*i+3] = t & 0xff; + t *= 17; + buffer[6*i+4] = (t >> 8) & 0xff; + buffer[6*i+5] = t & 0xff; + ++i; + } + + return; + + case 64: + /* As above in the 32 bit case. */ + while (i<128) + { + png_uint_32 t = v++; + buffer[8*i+0] = (t >> 8) & 0xff; + buffer[8*i+1] = t & 0xff; + buffer[8*i+4] = (t >> 8) & 0xff; + buffer[8*i+5] = t & 0xff; + t *= 257; + buffer[8*i+2] = (t >> 8) & 0xff; + buffer[8*i+3] = t & 0xff; + buffer[8*i+6] = (t >> 8) & 0xff; + buffer[8*i+7] = t & 0xff; + ++i; + } + return; + + default: + break; + } + + png_error(pp, "internal error"); +} + +/* This is just to do the right cast - could be changed to a function to check + * 'bd' but there isn't much point. + */ +#define DEPTH(bd) ((png_byte)(1U << (bd))) + +/* Make a standardized image given a an image colour type, bit depth and + * interlace type. The standard images have a very restricted range of + * rows and heights and are used for testing transforms rather than image + * layout details. See make_size_images below for a way to make images + * that test odd sizes along with the libpng interlace handling. + */ +static void +make_transform_image(png_store* PNG_CONST ps, png_byte PNG_CONST colour_type, + png_byte PNG_CONST bit_depth, int palette_number, int interlace_type, + png_const_charp name) +{ + context(ps, fault); + + Try + { + png_infop pi; + png_structp pp = set_store_for_write(ps, &pi, name); + png_uint_32 h; + + /* In the event of a problem return control to the Catch statement below + * to do the clean up - it is not possible to 'return' directly from a Try + * block. + */ + if (pp == NULL) + Throw ps; + + h = transform_height(pp, colour_type, bit_depth); + + png_set_IHDR(pp, pi, transform_width(pp, colour_type, bit_depth), h, + bit_depth, colour_type, interlace_type, + PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE); + +#ifdef PNG_TEXT_SUPPORTED + { + static char key[] = "image name"; /* must be writeable */ + size_t pos; + png_text text; + char copy[FILE_NAME_SIZE]; + + /* Use a compressed text string to test the correct interaction of text + * compression and IDAT compression. + */ + text.compression = PNG_TEXT_COMPRESSION_zTXt; + text.key = key; + /* Yuck: the text must be writable! */ + pos = safecat(copy, sizeof copy, 0, ps->wname); + text.text = copy; + text.text_length = pos; + text.itxt_length = 0; + text.lang = 0; + text.lang_key = 0; + + png_set_text(pp, pi, &text, 1); + } +#endif + + if (colour_type == 3) /* palette */ + init_standard_palette(ps, pp, pi, 1U << bit_depth, 1/*do tRNS*/); + + png_write_info(pp, pi); + + if (png_get_rowbytes(pp, pi) != + transform_rowsize(pp, colour_type, bit_depth)) + png_error(pp, "row size incorrect"); + + else + { + /* Somewhat confusingly this must be called *after* png_write_info + * because if it is called before, the information in *pp has not been + * updated to reflect the interlaced image. + */ + int npasses = png_set_interlace_handling(pp); + int pass; + + if (npasses != npasses_from_interlace_type(pp, interlace_type)) + png_error(pp, "write: png_set_interlace_handling failed"); + + for (pass=0; passtest, sizeof ps->test, 0, "make standard images"); + + /* Use next_format to enumerate all the combinations we test, including + * generating multiple low bit depth palette images. + */ + while (next_format(&colour_type, &bit_depth, &palette_number)) + { + int interlace_type; + + for (interlace_type = PNG_INTERLACE_NONE; + interlace_type < PNG_INTERLACE_LAST; ++interlace_type) + { + char name[FILE_NAME_SIZE]; + + standard_name(name, sizeof name, 0, colour_type, bit_depth, + palette_number, interlace_type, 0, 0, 0); + make_transform_image(ps, colour_type, bit_depth, palette_number, + interlace_type, name); + } + } +} + +/* The following two routines use the PNG interlace support macros from + * png.h to interlace or deinterlace rows. + */ +static void +interlace_row(png_bytep buffer, png_const_bytep imageRow, + unsigned int pixel_size, png_uint_32 w, int pass) +{ + png_uint_32 xin, xout, xstep; + + /* Note that this can, trivially, be optimized to a memcpy on pass 7, the + * code is presented this way to make it easier to understand. In practice + * consult the code in the libpng source to see other ways of doing this. + */ + xin = PNG_PASS_START_COL(pass); + xstep = 1U<= 8) + *buffer++ = (png_byte)y++, bit_width -= 8; + + /* There may be up to 7 remaining bits, these go in the most significant + * bits of the byte. + */ + if (bit_width > 0) + { + png_uint_32 mask = (1U<<(8-bit_width))-1; + *buffer = (png_byte)((*buffer & mask) | (y & ~mask)); + } +} + +static void +make_size_image(png_store* PNG_CONST ps, png_byte PNG_CONST colour_type, + png_byte PNG_CONST bit_depth, int PNG_CONST interlace_type, + png_uint_32 PNG_CONST w, png_uint_32 PNG_CONST h, + int PNG_CONST do_interlace) +{ + context(ps, fault); + + Try + { + png_infop pi; + png_structp pp; + unsigned int pixel_size; + + /* Make a name and get an appropriate id for the store: */ + char name[FILE_NAME_SIZE]; + PNG_CONST png_uint_32 id = FILEID(colour_type, bit_depth, 0/*palette*/, + interlace_type, w, h, do_interlace); + + standard_name_from_id(name, sizeof name, 0, id); + pp = set_store_for_write(ps, &pi, name); + + /* In the event of a problem return control to the Catch statement below + * to do the clean up - it is not possible to 'return' directly from a Try + * block. + */ + if (pp == NULL) + Throw ps; + + png_set_IHDR(pp, pi, w, h, bit_depth, colour_type, interlace_type, + PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE); + + if (colour_type == 3) /* palette */ + init_standard_palette(ps, pp, pi, 1U << bit_depth, 0/*do tRNS*/); + + png_write_info(pp, pi); + + /* Calculate the bit size, divide by 8 to get the byte size - this won't + * overflow because we know the w values are all small enough even for + * a system where 'unsigned int' is only 16 bits. + */ + pixel_size = bit_size(pp, colour_type, bit_depth); + if (png_get_rowbytes(pp, pi) != ((w * pixel_size) + 7) / 8) + png_error(pp, "row size incorrect"); + + else + { + int npasses = npasses_from_interlace_type(pp, interlace_type); + png_uint_32 y; + int pass; + png_byte image[16][SIZE_ROWMAX]; + + /* To help consistent error detection make the parts of this buffer + * that aren't set below all '1': + */ + memset(image, 0xff, sizeof image); + + if (!do_interlace && npasses != png_set_interlace_handling(pp)) + png_error(pp, "write: png_set_interlace_handling failed"); + + /* Prepare the whole image first to avoid making it 7 times: */ + for (y=0; y 0) + { + /* Set to all 1's for error detection (libpng tends to + * set unset things to 0). + */ + memset(tempRow, 0xff, sizeof tempRow); + interlace_row(tempRow, row, pixel_size, w, pass); + row = tempRow; + } + else + continue; + } + + /* Only get to here if the row has some pixels in it. */ + png_write_row(pp, row); + } + } + } + + png_write_end(pp, pi); + + /* And store this under the appropriate id, then clean up. */ + store_storefile(ps, id); + + store_write_reset(ps); + } + + Catch(fault) + { + /* Use the png_store returned by the exception. This may help the compiler + * because 'ps' is not used in this branch of the setjmp. Note that fault + * and ps will always be the same value. + */ + store_write_reset(fault); + } +} + +static void +make_size(png_store* PNG_CONST ps, png_byte PNG_CONST colour_type, int bdlo, + int PNG_CONST bdhi) +{ + for (; bdlo <= bdhi; ++bdlo) + { + png_uint_32 width; + + for (width = 1; width <= 16; ++width) + { + png_uint_32 height; + + for (height = 1; height <= 16; ++height) + { + /* The four combinations of DIY interlace and interlace or not - + * no interlace + DIY should be identical to no interlace with + * libpng doing it. + */ + make_size_image(ps, colour_type, DEPTH(bdlo), PNG_INTERLACE_NONE, + width, height, 0); + make_size_image(ps, colour_type, DEPTH(bdlo), PNG_INTERLACE_NONE, + width, height, 1); + make_size_image(ps, colour_type, DEPTH(bdlo), PNG_INTERLACE_ADAM7, + width, height, 0); + make_size_image(ps, colour_type, DEPTH(bdlo), PNG_INTERLACE_ADAM7, + width, height, 1); + } + } + } +} + +static void +make_size_images(png_store *ps) +{ + /* This is in case of errors. */ + safecat(ps->test, sizeof ps->test, 0, "make size images"); + + /* Arguments are colour_type, low bit depth, high bit depth + */ + make_size(ps, 0, 0, WRITE_BDHI); + make_size(ps, 2, 3, WRITE_BDHI); + make_size(ps, 3, 0, 3 /*palette: max 8 bits*/); + make_size(ps, 4, 3, WRITE_BDHI); + make_size(ps, 6, 3, WRITE_BDHI); +} + +/* Return a row based on image id and 'y' for checking: */ +static void +standard_row(png_structp pp, png_byte std[STANDARD_ROWMAX], png_uint_32 id, + png_uint_32 y) +{ + if (WIDTH_FROM_ID(id) == 0) + transform_row(pp, std, COL_FROM_ID(id), DEPTH_FROM_ID(id), y); + else + size_row(std, WIDTH_FROM_ID(id) * bit_size(pp, COL_FROM_ID(id), + DEPTH_FROM_ID(id)), y); +} + +/* Tests - individual test cases */ +/* Like 'make_standard' but errors are deliberately introduced into the calls + * to ensure that they get detected - it should not be possible to write an + * invalid image with libpng! + */ +#ifdef PNG_WARNINGS_SUPPORTED +static void +sBIT0_error_fn(png_structp pp, png_infop pi) +{ + /* 0 is invalid... */ + png_color_8 bad; + bad.red = bad.green = bad.blue = bad.gray = bad.alpha = 0; + png_set_sBIT(pp, pi, &bad); +} + +static void +sBIT_error_fn(png_structp pp, png_infop pi) +{ + png_byte bit_depth; + png_color_8 bad; + + if (png_get_color_type(pp, pi) == PNG_COLOR_TYPE_PALETTE) + bit_depth = 8; + + else + bit_depth = png_get_bit_depth(pp, pi); + + /* Now we know the bit depth we can easily generate an invalid sBIT entry */ + bad.red = bad.green = bad.blue = bad.gray = bad.alpha = + (png_byte)(bit_depth+1); + png_set_sBIT(pp, pi, &bad); +} + +static PNG_CONST struct +{ + void (*fn)(png_structp, png_infop); + PNG_CONST char *msg; + unsigned int warning :1; /* the error is a warning... */ +} error_test[] = + { + /* no warnings makes these errors undetectable. */ + { sBIT0_error_fn, "sBIT(0): failed to detect error", 1 }, + { sBIT_error_fn, "sBIT(too big): failed to detect error", 1 }, + }; + +static void +make_error(png_store* volatile psIn, png_byte PNG_CONST colour_type, + png_byte bit_depth, int interlace_type, int test, png_const_charp name) +{ + png_store * volatile ps = psIn; + + context(ps, fault); + + Try + { + png_structp pp; + png_infop pi; + + pp = set_store_for_write(ps, &pi, name); + + if (pp == NULL) + Throw ps; + + png_set_IHDR(pp, pi, transform_width(pp, colour_type, bit_depth), + transform_height(pp, colour_type, bit_depth), bit_depth, colour_type, + interlace_type, PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE); + + if (colour_type == 3) /* palette */ + init_standard_palette(ps, pp, pi, 1U << bit_depth, 0/*do tRNS*/); + + /* Time for a few errors; these are in various optional chunks, the + * standard tests test the standard chunks pretty well. + */ +# define exception__prev exception_prev_1 +# define exception__env exception_env_1 + Try + { + /* Expect this to throw: */ + ps->expect_error = !error_test[test].warning; + ps->expect_warning = error_test[test].warning; + ps->saw_warning = 0; + error_test[test].fn(pp, pi); + + /* Normally the error is only detected here: */ + png_write_info(pp, pi); + + /* And handle the case where it was only a warning: */ + if (ps->expect_warning && ps->saw_warning) + Throw ps; + + /* If we get here there is a problem, we have success - no error or + * no warning - when we shouldn't have success. Log an error. + */ + store_log(ps, pp, error_test[test].msg, 1 /*error*/); + } + + Catch (fault) + ps = fault; /* expected exit, make sure ps is not clobbered */ +#undef exception__prev +#undef exception__env + + /* And clear these flags */ + ps->expect_error = 0; + ps->expect_warning = 0; + + /* Now write the whole image, just to make sure that the detected, or + * undetected, errro has not created problems inside libpng. + */ + if (png_get_rowbytes(pp, pi) != + transform_rowsize(pp, colour_type, bit_depth)) + png_error(pp, "row size incorrect"); + + else + { + png_uint_32 h = transform_height(pp, colour_type, bit_depth); + int npasses = png_set_interlace_handling(pp); + int pass; + + if (npasses != npasses_from_interlace_type(pp, interlace_type)) + png_error(pp, "write: png_set_interlace_handling failed"); + + for (pass=0; passthis, colour_type, DEPTH(bdlo), interlace_type, + test, name); + + if (fail(pm)) + return 0; + } + } + } + + return 1; /* keep going */ +} +#endif + +static void +perform_error_test(png_modifier *pm) +{ +#ifdef PNG_WARNINGS_SUPPORTED /* else there are no cases that work! */ + /* Need to do this here because we just write in this test. */ + safecat(pm->this.test, sizeof pm->this.test, 0, "error test"); + + if (!make_errors(pm, 0, 0, WRITE_BDHI)) + return; + + if (!make_errors(pm, 2, 3, WRITE_BDHI)) + return; + + if (!make_errors(pm, 3, 0, 3)) + return; + + if (!make_errors(pm, 4, 3, WRITE_BDHI)) + return; + + if (!make_errors(pm, 6, 3, WRITE_BDHI)) + return; +#else + UNUSED(pm) +#endif +} + +/* This is just to validate the internal PNG formatting code - if this fails + * then the warning messages the library outputs will probably be garbage. + */ +static void +perform_formatting_test(png_store *volatile ps) +{ +#ifdef PNG_TIME_RFC1123_SUPPORTED + /* The handle into the formatting code is the RFC1123 support; this test does + * nothing if that is compiled out. + */ + context(ps, fault); + + Try + { + png_const_charp correct = "29 Aug 2079 13:53:60 +0000"; + png_const_charp result; + png_structp pp; + png_time pt; + + pp = set_store_for_write(ps, NULL, "libpng formatting test"); + + if (pp == NULL) + Throw ps; + + + /* Arbitrary settings: */ + pt.year = 2079; + pt.month = 8; + pt.day = 29; + pt.hour = 13; + pt.minute = 53; + pt.second = 60; /* a leap second */ + + result = png_convert_to_rfc1123(pp, &pt); + + if (result == NULL) + png_error(pp, "png_convert_to_rfc1123 failed"); + + if (strcmp(result, correct) != 0) + { + size_t pos = 0; + char msg[128]; + + pos = safecat(msg, sizeof msg, pos, "png_convert_to_rfc1123("); + pos = safecat(msg, sizeof msg, pos, correct); + pos = safecat(msg, sizeof msg, pos, ") returned: '"); + pos = safecat(msg, sizeof msg, pos, result); + pos = safecat(msg, sizeof msg, pos, "'"); + + png_error(pp, msg); + } + + store_write_reset(ps); + } + + Catch(fault) + { + store_write_reset(fault); + } +#else + UNUSED(ps) +#endif +} + +/* Because we want to use the same code in both the progressive reader and the + * sequential reader it is necessary to deal with the fact that the progressive + * reader callbacks only have one parameter (png_get_progressive_ptr()), so this + * must contain all the test parameters and all the local variables directly + * accessible to the sequential reader implementation. + * + * The technique adopted is to reinvent part of what Dijkstra termed a + * 'display'; an array of pointers to the stack frames of enclosing functions so + * that a nested function definition can access the local (C auto) variables of + * the functions that contain its definition. In fact C provides the first + * pointer (the local variables - the stack frame pointer) and the last (the + * global variables - the BCPL global vector typically implemented as global + * addresses), this code requires one more pointer to make the display - the + * local variables (and function call parameters) of the function that actually + * invokes either the progressive or sequential reader. + * + * Perhaps confusingly this technique is confounded with classes - the + * 'standard_display' defined here is sub-classed as the 'gamma_display' below. + * A gamma_display is a standard_display, taking advantage of the ANSI-C + * requirement that the pointer to the first member of a structure must be the + * same as the pointer to the structure. This allows us to reuse standard_ + * functions in the gamma test code; something that could not be done with + * nested functions! + */ +typedef struct standard_display +{ + png_store* ps; /* Test parameters (passed to the function) */ + png_byte colour_type; + png_byte bit_depth; + png_byte red_sBIT; /* Input data sBIT values. */ + png_byte green_sBIT; + png_byte blue_sBIT; + png_byte alpha_sBIT; + int interlace_type; + png_uint_32 id; /* Calculated file ID */ + png_uint_32 w; /* Width of image */ + png_uint_32 h; /* Height of image */ + int npasses; /* Number of interlaced passes */ + png_uint_32 pixel_size; /* Width of one pixel in bits */ + png_uint_32 bit_width; /* Width of output row in bits */ + size_t cbRow; /* Bytes in a row of the output image */ + int do_interlace; /* Do interlacing internally */ + int is_transparent; /* Transparency information was present. */ + int speed; /* Doing a speed test */ + int use_update_info;/* Call update_info, not start_image */ + struct + { + png_uint_16 red; + png_uint_16 green; + png_uint_16 blue; + } transparent; /* The transparent color, if set. */ + int npalette; /* Number of entries in the palette. */ + store_palette + palette; +} standard_display; + +static void +standard_display_init(standard_display *dp, png_store* ps, png_uint_32 id, + int do_interlace, int use_update_info) +{ + memset(dp, 0, sizeof *dp); + + dp->ps = ps; + dp->colour_type = COL_FROM_ID(id); + dp->bit_depth = DEPTH_FROM_ID(id); + if (dp->bit_depth < 1 || dp->bit_depth > 16) + internal_error(ps, "internal: bad bit depth"); + if (dp->colour_type == 3) + dp->red_sBIT = dp->blue_sBIT = dp->green_sBIT = dp->alpha_sBIT = 8; + else + dp->red_sBIT = dp->blue_sBIT = dp->green_sBIT = dp->alpha_sBIT = + dp->bit_depth; + dp->interlace_type = INTERLACE_FROM_ID(id); + dp->id = id; + /* All the rest are filled in after the read_info: */ + dp->w = 0; + dp->h = 0; + dp->npasses = 0; + dp->pixel_size = 0; + dp->bit_width = 0; + dp->cbRow = 0; + dp->do_interlace = do_interlace; + dp->is_transparent = 0; + dp->speed = ps->speed; + dp->use_update_info = use_update_info; + dp->npalette = 0; + /* Preset the transparent color to black: */ + memset(&dp->transparent, 0, sizeof dp->transparent); + /* Preset the palette to full intensity/opaque througout: */ + memset(dp->palette, 0xff, sizeof dp->palette); +} + +/* Initialize the palette fields - this must be done later because the palette + * comes from the particular png_store_file that is selected. + */ +static void +standard_palette_init(standard_display *dp) +{ + store_palette_entry *palette = store_current_palette(dp->ps, &dp->npalette); + + /* The remaining entries remain white/opaque. */ + if (dp->npalette > 0) + { + int i = dp->npalette; + memcpy(dp->palette, palette, i * sizeof *palette); + + /* Check for a non-opaque palette entry: */ + while (--i >= 0) + if (palette[i].alpha < 255) + break; + +# ifdef __GNUC__ + /* GCC can't handle the more obviously optimizable version. */ + if (i >= 0) + dp->is_transparent = 1; + else + dp->is_transparent = 0; +# else + dp->is_transparent = (i >= 0); +# endif + } +} + +/* Utility to read the palette from the PNG file and convert it into + * store_palette format. This returns 1 if there is any transparency in the + * palette (it does not check for a transparent colour in the non-palette case.) + */ +static int +read_palette(store_palette palette, int *npalette, png_structp pp, png_infop pi) +{ + png_colorp pal; + png_bytep trans_alpha; + int num; + + pal = 0; + *npalette = -1; + + if (png_get_PLTE(pp, pi, &pal, npalette) & PNG_INFO_PLTE) + { + int i = *npalette; + + if (i <= 0 || i > 256) + png_error(pp, "validate: invalid PLTE count"); + + while (--i >= 0) + { + palette[i].red = pal[i].red; + palette[i].green = pal[i].green; + palette[i].blue = pal[i].blue; + } + + /* Mark the remainder of the entries with a flag value (other than + * white/opaque which is the flag value stored above.) + */ + memset(palette + *npalette, 126, (256-*npalette) * sizeof *palette); + } + + else /* !png_get_PLTE */ + { + if (*npalette != (-1)) + png_error(pp, "validate: invalid PLTE result"); + /* But there is no palette, so record this: */ + *npalette = 0; + memset(palette, 113, sizeof palette); + } + + trans_alpha = 0; + num = 2; /* force error below */ + if ((png_get_tRNS(pp, pi, &trans_alpha, &num, 0) & PNG_INFO_tRNS) != 0 && + (trans_alpha != NULL || num != 1/*returns 1 for a transparent color*/) && + /* Oops, if a palette tRNS gets expanded png_read_update_info (at least so + * far as 1.5.4) does not remove the trans_alpha pointer, only num_trans, + * so in the above call we get a success, we get a pointer (who knows what + * to) and we get num_trans == 0: + */ + !(trans_alpha != NULL && num == 0)) /* TODO: fix this in libpng. */ + { + int i; + + /* Any of these are crash-worthy - given the implementation of + * png_get_tRNS up to 1.5 an app won't crash if it just checks the + * result above and fails to check that the variables it passed have + * actually been filled in! Note that if the app were to pass the + * last, png_color_16p, variable too it couldn't rely on this. + */ + if (trans_alpha == NULL || num <= 0 || num > 256 || num > *npalette) + png_error(pp, "validate: unexpected png_get_tRNS (palette) result"); + + for (i=0; iis_transparent) + png_error(pp, "validate: palette transparency changed"); + + if (npalette != dp->npalette) + { + size_t pos = 0; + char msg[64]; + + pos = safecat(msg, sizeof msg, pos, "validate: palette size changed: "); + pos = safecatn(msg, sizeof msg, pos, dp->npalette); + pos = safecat(msg, sizeof msg, pos, " -> "); + pos = safecatn(msg, sizeof msg, pos, npalette); + png_error(pp, msg); + } + + { + int i = npalette; /* npalette is aliased */ + + while (--i >= 0) + if (palette[i].red != dp->palette[i].red || + palette[i].green != dp->palette[i].green || + palette[i].blue != dp->palette[i].blue || + palette[i].alpha != dp->palette[i].alpha) + png_error(pp, "validate: PLTE or tRNS chunk changed"); + } +} + +/* By passing a 'standard_display' the progressive callbacks can be used + * directly by the sequential code, the functions suffixed "_imp" are the + * implementations, the functions without the suffix are the callbacks. + * + * The code for the info callback is split into two because this callback calls + * png_read_update_info or png_start_read_image and what gets called depends on + * whether the info needs updating (we want to test both calls in pngvalid.) + */ +static void +standard_info_part1(standard_display *dp, png_structp pp, png_infop pi) +{ + if (png_get_bit_depth(pp, pi) != dp->bit_depth) + png_error(pp, "validate: bit depth changed"); + + if (png_get_color_type(pp, pi) != dp->colour_type) + png_error(pp, "validate: color type changed"); + + if (png_get_filter_type(pp, pi) != PNG_FILTER_TYPE_BASE) + png_error(pp, "validate: filter type changed"); + + if (png_get_interlace_type(pp, pi) != dp->interlace_type) + png_error(pp, "validate: interlacing changed"); + + if (png_get_compression_type(pp, pi) != PNG_COMPRESSION_TYPE_BASE) + png_error(pp, "validate: compression type changed"); + + dp->w = png_get_image_width(pp, pi); + + if (dp->w != standard_width(pp, dp->id)) + png_error(pp, "validate: image width changed"); + + dp->h = png_get_image_height(pp, pi); + + if (dp->h != standard_height(pp, dp->id)) + png_error(pp, "validate: image height changed"); + + /* Record (but don't check at present) the input sBIT according to the colour + * type information. + */ + { + png_color_8p sBIT = 0; + + if (png_get_sBIT(pp, pi, &sBIT) & PNG_INFO_sBIT) + { + int sBIT_invalid = 0; + + if (sBIT == 0) + png_error(pp, "validate: unexpected png_get_sBIT result"); + + if (dp->colour_type & PNG_COLOR_MASK_COLOR) + { + if (sBIT->red == 0 || sBIT->red > dp->bit_depth) + sBIT_invalid = 1; + else + dp->red_sBIT = sBIT->red; + + if (sBIT->green == 0 || sBIT->green > dp->bit_depth) + sBIT_invalid = 1; + else + dp->green_sBIT = sBIT->green; + + if (sBIT->blue == 0 || sBIT->blue > dp->bit_depth) + sBIT_invalid = 1; + else + dp->blue_sBIT = sBIT->blue; + } + + else /* !COLOR */ + { + if (sBIT->gray == 0 || sBIT->gray > dp->bit_depth) + sBIT_invalid = 1; + else + dp->blue_sBIT = dp->green_sBIT = dp->red_sBIT = sBIT->gray; + } + + /* All 8 bits in tRNS for a palette image are significant - see the + * spec. + */ + if (dp->colour_type & PNG_COLOR_MASK_ALPHA) + { + if (sBIT->alpha == 0 || sBIT->alpha > dp->bit_depth) + sBIT_invalid = 1; + else + dp->alpha_sBIT = sBIT->alpha; + } + + if (sBIT_invalid) + png_error(pp, "validate: sBIT value out of range"); + } + } + + /* Important: this is validating the value *before* any transforms have been + * put in place. It doesn't matter for the standard tests, where there are + * no transforms, but it does for other tests where rowbytes may change after + * png_read_update_info. + */ + if (png_get_rowbytes(pp, pi) != standard_rowsize(pp, dp->id)) + png_error(pp, "validate: row size changed"); + + /* Validate the colour type 3 palette (this can be present on other color + * types.) + */ + standard_palette_validate(dp, pp, pi); + + /* In any case always check for a tranparent color (notice that the + * colour type 3 case must not give a successful return on the get_tRNS call + * with these arguments!) + */ + { + png_color_16p trans_color = 0; + + if (png_get_tRNS(pp, pi, 0, 0, &trans_color) & PNG_INFO_tRNS) + { + if (trans_color == 0) + png_error(pp, "validate: unexpected png_get_tRNS (color) result"); + + switch (dp->colour_type) + { + case 0: + dp->transparent.red = dp->transparent.green = dp->transparent.blue = + trans_color->gray; + dp->is_transparent = 1; + break; + + case 2: + dp->transparent.red = trans_color->red; + dp->transparent.green = trans_color->green; + dp->transparent.blue = trans_color->blue; + dp->is_transparent = 1; + break; + + case 3: + /* Not expected because it should result in the array case + * above. + */ + png_error(pp, "validate: unexpected png_get_tRNS result"); + break; + + default: + png_error(pp, "validate: invalid tRNS chunk with alpha image"); + } + } + } + + /* Read the number of passes - expected to match the value used when + * creating the image (interlaced or not). This has the side effect of + * turning on interlace handling (if do_interlace is not set.) + */ + dp->npasses = npasses_from_interlace_type(pp, dp->interlace_type); + if (!dp->do_interlace && dp->npasses != png_set_interlace_handling(pp)) + png_error(pp, "validate: file changed interlace type"); + + /* Caller calls png_read_update_info or png_start_read_image now, then calls + * part2. + */ +} + +/* This must be called *after* the png_read_update_info call to get the correct + * 'rowbytes' value, otherwise png_get_rowbytes will refer to the untransformed + * image. + */ +static void +standard_info_part2(standard_display *dp, png_structp pp, png_infop pi, + int nImages) +{ + /* Record cbRow now that it can be found. */ + dp->pixel_size = bit_size(pp, png_get_color_type(pp, pi), + png_get_bit_depth(pp, pi)); + dp->bit_width = png_get_image_width(pp, pi) * dp->pixel_size; + dp->cbRow = png_get_rowbytes(pp, pi); + + /* Validate the rowbytes here again. */ + if (dp->cbRow != (dp->bit_width+7)/8) + png_error(pp, "bad png_get_rowbytes calculation"); + + /* Then ensure there is enough space for the output image(s). */ + store_ensure_image(dp->ps, pp, nImages, dp->cbRow, dp->h); +} + +static void +standard_info_imp(standard_display *dp, png_structp pp, png_infop pi, + int nImages) +{ + /* Note that the validation routine has the side effect of turning on + * interlace handling in the subsequent code. + */ + standard_info_part1(dp, pp, pi); + + /* And the info callback has to call this (or png_read_update_info - see + * below in the png_modifier code for that variant. + */ + if (dp->use_update_info) + { + /* For debugging the effect of multiple calls: */ + int i = dp->use_update_info; + while (i-- > 0) + png_read_update_info(pp, pi); + } + + else + png_start_read_image(pp); + + /* Validate the height, width and rowbytes plus ensure that sufficient buffer + * exists for decoding the image. + */ + standard_info_part2(dp, pp, pi, nImages); +} + +static void +standard_info(png_structp pp, png_infop pi) +{ + standard_display *dp = voidcast(standard_display*, + png_get_progressive_ptr(pp)); + + /* Call with nImages==1 because the progressive reader can only produce one + * image. + */ + standard_info_imp(dp, pp, pi, 1 /*only one image*/); +} + +static void +progressive_row(png_structp pp, png_bytep new_row, png_uint_32 y, int pass) +{ + PNG_CONST standard_display *dp = voidcast(standard_display*, + png_get_progressive_ptr(pp)); + + /* When handling interlacing some rows will be absent in each pass, the + * callback still gets called, but with a NULL pointer. This is checked + * in the 'else' clause below. We need our own 'cbRow', but we can't call + * png_get_rowbytes because we got no info structure. + */ + if (new_row != NULL) + { + png_bytep row; + + /* In the case where the reader doesn't do the interlace it gives + * us the y in the sub-image: + */ + if (dp->do_interlace && dp->interlace_type == PNG_INTERLACE_ADAM7) + { +#ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED + /* Use this opportunity to validate the png 'current' APIs: */ + if (y != png_get_current_row_number(pp)) + png_error(pp, "png_get_current_row_number is broken"); + + if (pass != png_get_current_pass_number(pp)) + png_error(pp, "png_get_current_pass_number is broken"); +#endif + + y = PNG_ROW_FROM_PASS_ROW(y, pass); + } + + /* Validate this just in case. */ + if (y >= dp->h) + png_error(pp, "invalid y to progressive row callback"); + + row = store_image_row(dp->ps, pp, 0, y); + +#ifdef PNG_READ_INTERLACING_SUPPORTED + /* Combine the new row into the old: */ + if (dp->do_interlace) + { + if (dp->interlace_type == PNG_INTERLACE_ADAM7) + deinterlace_row(row, new_row, dp->pixel_size, dp->w, pass); + else + row_copy(row, new_row, dp->pixel_size * dp->w); + } + else + png_progressive_combine_row(pp, row, new_row); + } else if (dp->interlace_type == PNG_INTERLACE_ADAM7 && + PNG_ROW_IN_INTERLACE_PASS(y, pass) && + PNG_PASS_COLS(dp->w, pass) > 0) + png_error(pp, "missing row in progressive de-interlacing"); +#endif /* PNG_READ_INTERLACING_SUPPORTED */ +} + +static void +sequential_row(standard_display *dp, png_structp pp, png_infop pi, + PNG_CONST int iImage, PNG_CONST int iDisplay) +{ + PNG_CONST int npasses = dp->npasses; + PNG_CONST int do_interlace = dp->do_interlace && + dp->interlace_type == PNG_INTERLACE_ADAM7; + PNG_CONST png_uint_32 height = standard_height(pp, dp->id); + PNG_CONST png_uint_32 width = standard_width(pp, dp->id); + PNG_CONST png_store* ps = dp->ps; + int pass; + + for (pass=0; pass 0 && PNG_ROW_IN_INTERLACE_PASS(y, pass)) + { + /* Read the row into a pair of temporary buffers, then do the + * merge here into the output rows. + */ + png_byte row[STANDARD_ROWMAX], display[STANDARD_ROWMAX]; + + /* The following aids (to some extent) error detection - we can + * see where png_read_row wrote. Use opposite values in row and + * display to make this easier. Don't use 0xff (which is used in + * the image write code to fill unused bits) or 0 (which is a + * likely value to overwrite unused bits with). + */ + memset(row, 0xc5, sizeof row); + memset(display, 0x5c, sizeof display); + + png_read_row(pp, row, display); + + if (iImage >= 0) + deinterlace_row(store_image_row(ps, pp, iImage, y), row, + dp->pixel_size, dp->w, pass); + + if (iDisplay >= 0) + deinterlace_row(store_image_row(ps, pp, iDisplay, y), display, + dp->pixel_size, dp->w, pass); + } + } + else + png_read_row(pp, + iImage >= 0 ? store_image_row(ps, pp, iImage, y) : NULL, + iDisplay >= 0 ? store_image_row(ps, pp, iDisplay, y) : NULL); + } + } + + /* And finish the read operation (only really necessary if the caller wants + * to find additional data in png_info from chunks after the last IDAT.) + */ + png_read_end(pp, pi); +} + +static void +standard_row_validate(standard_display *dp, png_structp pp, + int iImage, int iDisplay, png_uint_32 y) +{ + int where; + png_byte std[STANDARD_ROWMAX]; + + /* The row must be pre-initialized to the magic number here for the size + * tests to pass: + */ + memset(std, 178, sizeof std); + standard_row(pp, std, dp->id, y); + + /* At the end both the 'row' and 'display' arrays should end up identical. + * In earlier passes 'row' will be partially filled in, with only the pixels + * that have been read so far, but 'display' will have those pixels + * replicated to fill the unread pixels while reading an interlaced image. +#if PNG_LIBPNG_VER < 10506 + * The side effect inside the libpng sequential reader is that the 'row' + * array retains the correct values for unwritten pixels within the row + * bytes, while the 'display' array gets bits off the end of the image (in + * the last byte) trashed. Unfortunately in the progressive reader the + * row bytes are always trashed, so we always do a pixel_cmp here even though + * a memcmp of all cbRow bytes will succeed for the sequential reader. +#endif + */ + if (iImage >= 0 && + (where = pixel_cmp(std, store_image_row(dp->ps, pp, iImage, y), + dp->bit_width)) != 0) + { + char msg[64]; + sprintf(msg, "PNG image row[%d][%d] changed from %.2x to %.2x", y, + where-1, std[where-1], + store_image_row(dp->ps, pp, iImage, y)[where-1]); + png_error(pp, msg); + } + +#if PNG_LIBPNG_VER < 10506 + /* In this case use pixel_cmp because we need to compare a partial + * byte at the end of the row if the row is not an exact multiple + * of 8 bits wide. (This is fixed in libpng-1.5.6 and pixel_cmp is + * changed to match!) + */ +#endif + if (iDisplay >= 0 && + (where = pixel_cmp(std, store_image_row(dp->ps, pp, iDisplay, y), + dp->bit_width)) != 0) + { + char msg[64]; + sprintf(msg, "display row[%d][%d] changed from %.2x to %.2x", y, + where-1, std[where-1], + store_image_row(dp->ps, pp, iDisplay, y)[where-1]); + png_error(pp, msg); + } +} + +static void +standard_image_validate(standard_display *dp, png_structp pp, int iImage, + int iDisplay) +{ + png_uint_32 y; + + if (iImage >= 0) + store_image_check(dp->ps, pp, iImage); + + if (iDisplay >= 0) + store_image_check(dp->ps, pp, iDisplay); + + for (y=0; yh; ++y) + standard_row_validate(dp, pp, iImage, iDisplay, y); + + /* This avoids false positives if the validation code is never called! */ + dp->ps->validated = 1; +} + +static void +standard_end(png_structp pp, png_infop pi) +{ + standard_display *dp = voidcast(standard_display*, + png_get_progressive_ptr(pp)); + + UNUSED(pi) + + /* Validate the image - progressive reading only produces one variant for + * interlaced images. + */ + standard_image_validate(dp, pp, 0, -1); +} + +/* A single test run checking the standard image to ensure it is not damaged. */ +static void +standard_test(png_store* PNG_CONST psIn, png_uint_32 PNG_CONST id, + int do_interlace, int use_update_info) +{ + standard_display d; + context(psIn, fault); + + /* Set up the display (stack frame) variables from the arguments to the + * function and initialize the locals that are filled in later. + */ + standard_display_init(&d, psIn, id, do_interlace, use_update_info); + + /* Everything is protected by a Try/Catch. The functions called also + * typically have local Try/Catch blocks. + */ + Try + { + png_structp pp; + png_infop pi; + + /* Get a png_struct for reading the image. This will throw an error if it + * fails, so we don't need to check the result. + */ + pp = set_store_for_read(d.ps, &pi, d.id, + d.do_interlace ? (d.ps->progressive ? + "pngvalid progressive deinterlacer" : + "pngvalid sequential deinterlacer") : (d.ps->progressive ? + "progressive reader" : "sequential reader")); + + /* Initialize the palette correctly from the png_store_file. */ + standard_palette_init(&d); + + /* Introduce the correct read function. */ + if (d.ps->progressive) + { + png_set_progressive_read_fn(pp, &d, standard_info, progressive_row, + standard_end); + + /* Now feed data into the reader until we reach the end: */ + store_progressive_read(d.ps, pp, pi); + } + else + { + /* Note that this takes the store, not the display. */ + png_set_read_fn(pp, d.ps, store_read); + + /* Check the header values: */ + png_read_info(pp, pi); + + /* The code tests both versions of the images that the sequential + * reader can produce. + */ + standard_info_imp(&d, pp, pi, 2 /*images*/); + + /* Need the total bytes in the image below; we can't get to this point + * unless the PNG file values have been checked against the expected + * values. + */ + { + sequential_row(&d, pp, pi, 0, 1); + + /* After the last pass loop over the rows again to check that the + * image is correct. + */ + if (!d.speed) + standard_image_validate(&d, pp, 0, 1); + else + d.ps->validated = 1; + } + } + + /* Check for validation. */ + if (!d.ps->validated) + png_error(pp, "image read failed silently"); + + /* Successful completion. */ + } + + Catch(fault) + d.ps = fault; /* make sure this hasn't been clobbered. */ + + /* In either case clean up the store. */ + store_read_reset(d.ps); +} + +static int +test_standard(png_modifier* PNG_CONST pm, png_byte PNG_CONST colour_type, + int bdlo, int PNG_CONST bdhi) +{ + for (; bdlo <= bdhi; ++bdlo) + { + int interlace_type; + + for (interlace_type = PNG_INTERLACE_NONE; + interlace_type < PNG_INTERLACE_LAST; ++interlace_type) + { + standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), 0/*palette*/, + interlace_type, 0, 0, 0), 0/*do_interlace*/, pm->use_update_info); + + if (fail(pm)) + return 0; + } + } + + return 1; /* keep going */ +} + +static void +perform_standard_test(png_modifier *pm) +{ + /* Test each colour type over the valid range of bit depths (expressed as + * log2(bit_depth) in turn, stop as soon as any error is detected. + */ + if (!test_standard(pm, 0, 0, READ_BDHI)) + return; + + if (!test_standard(pm, 2, 3, READ_BDHI)) + return; + + if (!test_standard(pm, 3, 0, 3)) + return; + + if (!test_standard(pm, 4, 3, READ_BDHI)) + return; + + if (!test_standard(pm, 6, 3, READ_BDHI)) + return; +} + + +/********************************** SIZE TESTS ********************************/ +static int +test_size(png_modifier* PNG_CONST pm, png_byte PNG_CONST colour_type, + int bdlo, int PNG_CONST bdhi) +{ + /* Run the tests on each combination. + * + * NOTE: on my 32 bit x86 each of the following blocks takes + * a total of 3.5 seconds if done across every combo of bit depth + * width and height. This is a waste of time in practice, hence the + * hinc and winc stuff: + */ + static PNG_CONST png_byte hinc[] = {1, 3, 11, 1, 5}; + static PNG_CONST png_byte winc[] = {1, 9, 5, 7, 1}; + for (; bdlo <= bdhi; ++bdlo) + { + png_uint_32 h, w; + + for (h=1; h<=16; h+=hinc[bdlo]) for (w=1; w<=16; w+=winc[bdlo]) + { + /* First test all the 'size' images against the sequential + * reader using libpng to deinterlace (where required.) This + * validates the write side of libpng. There are four possibilities + * to validate. + */ + standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), 0/*palette*/, + PNG_INTERLACE_NONE, w, h, 0), 0/*do_interlace*/, + pm->use_update_info); + + if (fail(pm)) + return 0; + + standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), 0/*palette*/, + PNG_INTERLACE_NONE, w, h, 1), 0/*do_interlace*/, + pm->use_update_info); + + if (fail(pm)) + return 0; + + standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), 0/*palette*/, + PNG_INTERLACE_ADAM7, w, h, 0), 0/*do_interlace*/, + pm->use_update_info); + + if (fail(pm)) + return 0; + + standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), 0/*palette*/, + PNG_INTERLACE_ADAM7, w, h, 1), 0/*do_interlace*/, + pm->use_update_info); + + if (fail(pm)) + return 0; + + /* Now validate the interlaced read side - do_interlace true, + * in the progressive case this does actually make a difference + * to the code used in the non-interlaced case too. + */ + standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), 0/*palette*/, + PNG_INTERLACE_NONE, w, h, 0), 1/*do_interlace*/, + pm->use_update_info); + + if (fail(pm)) + return 0; + + standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), 0/*palette*/, + PNG_INTERLACE_ADAM7, w, h, 0), 1/*do_interlace*/, + pm->use_update_info); + + if (fail(pm)) + return 0; + } + } + + return 1; /* keep going */ +} + +static void +perform_size_test(png_modifier *pm) +{ + /* Test each colour type over the valid range of bit depths (expressed as + * log2(bit_depth) in turn, stop as soon as any error is detected. + */ + if (!test_size(pm, 0, 0, READ_BDHI)) + return; + + if (!test_size(pm, 2, 3, READ_BDHI)) + return; + + /* For the moment don't do the palette test - it's a waste of time when + * compared to the grayscale test. + */ +#if 0 + if (!test_size(pm, 3, 0, 3)) + return; +#endif + + if (!test_size(pm, 4, 3, READ_BDHI)) + return; + + if (!test_size(pm, 6, 3, READ_BDHI)) + return; +} + + +/******************************* TRANSFORM TESTS ******************************/ +#ifdef PNG_READ_TRANSFORMS_SUPPORTED +/* A set of tests to validate libpng image transforms. The possibilities here + * are legion because the transforms can be combined in a combinatorial + * fashion. To deal with this some measure of restraint is required, otherwise + * the tests would take forever. + */ +typedef struct image_pixel +{ + /* A local (pngvalid) representation of a PNG pixel, in all its + * various forms. + */ + unsigned int red, green, blue, alpha; /* For non-palette images. */ + unsigned int palette_index; /* For a palette image. */ + png_byte colour_type; /* As in the spec. */ + png_byte bit_depth; /* Defines bit size in row */ + png_byte sample_depth; /* Scale of samples */ + int have_tRNS; /* tRNS chunk may need processing */ + + /* For checking the code calculates double precision floating point values + * along with an error value, accumulated from the transforms. Because an + * sBIT setting allows larger error bounds (indeed, by the spec, apparently + * up to just less than +/-1 in the scaled value) the *lowest* sBIT for each + * channel is stored. This sBIT value is folded in to the stored error value + * at the end of the application of the transforms to the pixel. + */ + double redf, greenf, bluef, alphaf; + double rede, greene, bluee, alphae; + png_byte red_sBIT, green_sBIT, blue_sBIT, alpha_sBIT; +} image_pixel; + +/* Shared utility function, see below. */ +static void +image_pixel_setf(image_pixel *this, unsigned int max) +{ + this->redf = this->red / (double)max; + this->greenf = this->green / (double)max; + this->bluef = this->blue / (double)max; + this->alphaf = this->alpha / (double)max; + + if (this->red < max) + this->rede = this->redf * DBL_EPSILON; + else + this->rede = 0; + if (this->green < max) + this->greene = this->greenf * DBL_EPSILON; + else + this->greene = 0; + if (this->blue < max) + this->bluee = this->bluef * DBL_EPSILON; + else + this->bluee = 0; + if (this->alpha < max) + this->alphae = this->alphaf * DBL_EPSILON; + else + this->alphae = 0; +} + +/* Initialize the structure for the next pixel - call this before doing any + * transforms and call it for each pixel since all the fields may need to be + * reset. + */ +static void +image_pixel_init(image_pixel *this, png_const_bytep row, png_byte colour_type, + png_byte bit_depth, png_uint_32 x, store_palette palette) +{ + PNG_CONST png_byte sample_depth = (png_byte)(colour_type == + PNG_COLOR_TYPE_PALETTE ? 8 : bit_depth); + PNG_CONST unsigned int max = (1U<palette_index = this->red = this->green = this->blue = + sample(row, colour_type, bit_depth, x, 0); + this->alpha = max; + this->red_sBIT = this->green_sBIT = this->blue_sBIT = this->alpha_sBIT = + sample_depth; + + /* Then override as appropriate: */ + if (colour_type == 3) /* palette */ + { + /* This permits the caller to default to the sample value. */ + if (palette != 0) + { + PNG_CONST unsigned int i = this->palette_index; + + this->red = palette[i].red; + this->green = palette[i].green; + this->blue = palette[i].blue; + this->alpha = palette[i].alpha; + } + } + + else /* not palette */ + { + unsigned int i = 0; + + if (colour_type & 2) + { + this->green = sample(row, colour_type, bit_depth, x, 1); + this->blue = sample(row, colour_type, bit_depth, x, 2); + i = 2; + } + if (colour_type & 4) + this->alpha = sample(row, colour_type, bit_depth, x, ++i); + } + + /* Calculate the scaled values, these are simply the values divided by + * 'max' and the error is initialized to the double precision epsilon value + * from the header file. + */ + image_pixel_setf(this, max); + + /* Store the input information for use in the transforms - these will + * modify the information. + */ + this->colour_type = colour_type; + this->bit_depth = bit_depth; + this->sample_depth = sample_depth; + this->have_tRNS = 0; +} + +/* Convert a palette image to an rgb image. This necessarily converts the tRNS + * chunk at the same time, because the tRNS will be in palette form. The way + * palette validation works means that the original palette is never updated, + * instead the image_pixel value from the row contains the RGB of the + * corresponding palette entry and *this* is updated. Consequently this routine + * only needs to change the colour type information. + */ +static void +image_pixel_convert_PLTE(image_pixel *this) +{ + if (this->colour_type == PNG_COLOR_TYPE_PALETTE) + { + if (this->have_tRNS) + { + this->colour_type = PNG_COLOR_TYPE_RGB_ALPHA; + this->have_tRNS = 0; + } + else + this->colour_type = PNG_COLOR_TYPE_RGB; + + /* The bit depth of the row changes at this point too (notice that this is + * the row format, not the sample depth, which is separate.) + */ + this->bit_depth = 8; + } +} + +/* Add an alpha channel; this will import the tRNS information because tRNS is + * not valid in an alpha image. The bit depth will invariably be set to at + * least 8. Palette images will be converted to alpha (using the above API). + */ +static void +image_pixel_add_alpha(image_pixel *this, PNG_CONST standard_display *display) +{ + if (this->colour_type == PNG_COLOR_TYPE_PALETTE) + image_pixel_convert_PLTE(this); + + if ((this->colour_type & PNG_COLOR_MASK_ALPHA) == 0) + { + if (this->colour_type == PNG_COLOR_TYPE_GRAY) + { + if (this->bit_depth < 8) + this->bit_depth = 8; + + if (this->have_tRNS) + { + this->have_tRNS = 0; + + /* Check the input, original, channel value here against the + * original tRNS gray chunk valie. + */ + if (this->red == display->transparent.red) + this->alphaf = 0; + else + this->alphaf = 1; + } + else + this->alphaf = 1; + + this->colour_type = PNG_COLOR_TYPE_GRAY_ALPHA; + } + + else if (this->colour_type == PNG_COLOR_TYPE_RGB) + { + if (this->have_tRNS) + { + this->have_tRNS = 0; + + /* Again, check the exact input values, not the current transformed + * value! + */ + if (this->red == display->transparent.red && + this->green == display->transparent.green && + this->blue == display->transparent.blue) + this->alphaf = 0; + else + this->alphaf = 1; + + this->colour_type = PNG_COLOR_TYPE_RGB_ALPHA; + } + } + + /* The error in the alpha is zero and the sBIT value comes from the + * original sBIT data (actually it will always be the original bit depth). + */ + this->alphae = 0; + this->alpha_sBIT = display->alpha_sBIT; + } +} + +struct transform_display; +typedef struct image_transform +{ + /* The name of this transform: a string. */ + PNG_CONST char *name; + + /* Each transform can be disabled from the command line: */ + int enable; + + /* The global list of transforms; read only. */ + struct image_transform *PNG_CONST list; + + /* The global count of the number of times this transform has been set on an + * image. + */ + unsigned int global_use; + + /* The local count of the number of times this transform has been set. */ + unsigned int local_use; + + /* The next transform in the list, each transform must call its own next + * transform after it has processed the pixel successfully. + */ + PNG_CONST struct image_transform *next; + + /* A single transform for the image, expressed as a series of function + * callbacks and some space for values. + * + * First a callback to add any required modifications to the png_modifier; + * this gets called just before the modifier is set up for read. + */ + void (*ini)(PNG_CONST struct image_transform *this, + struct transform_display *that); + + /* And a callback to set the transform on the current png_read_struct: + */ + void (*set)(PNG_CONST struct image_transform *this, + struct transform_display *that, png_structp pp, png_infop pi); + + /* Then a transform that takes an input pixel in one PNG format or another + * and modifies it by a pngvalid implementation of the transform (thus + * duplicating the libpng intent without, we hope, duplicating the bugs + * in the libpng implementation!) The png_structp is solely to allow error + * reporting via png_error and png_warning. + */ + void (*mod)(PNG_CONST struct image_transform *this, image_pixel *that, + png_structp pp, PNG_CONST struct transform_display *display); + + /* Add this transform to the list and return true if the transform is + * meaningful for this colour type and bit depth - if false then the + * transform should have no effect on the image so there's not a lot of + * point running it. + */ + int (*add)(struct image_transform *this, + PNG_CONST struct image_transform **that, png_byte colour_type, + png_byte bit_depth); +} image_transform; + +typedef struct transform_display +{ + standard_display this; + + /* Parameters */ + png_modifier* pm; + PNG_CONST image_transform* transform_list; + + /* Local variables */ + png_byte output_colour_type; + png_byte output_bit_depth; + + /* Modifications (not necessarily used.) */ + gama_modification gama_mod; + chrm_modification chrm_mod; + srgb_modification srgb_mod; +} transform_display; + +/* Set sRGB, cHRM and gAMA transforms as required by the current encoding. */ +static void +transform_set_encoding(transform_display *this) +{ + /* Set up the png_modifier '_current' fields then use these to determine how + * to add appropriate chunks. + */ + png_modifier *pm = this->pm; + + modifier_set_encoding(pm); + + if (modifier_color_encoding_is_set(pm)) + { + if (modifier_color_encoding_is_sRGB(pm)) + srgb_modification_init(&this->srgb_mod, pm, PNG_sRGB_INTENT_ABSOLUTE); + + else + { + /* Set gAMA and cHRM separately. */ + gama_modification_init(&this->gama_mod, pm, pm->current_gamma); + + if (pm->current_encoding != 0) + chrm_modification_init(&this->chrm_mod, pm, pm->current_encoding); + } + } +} + +/* Three functions to end the list: */ +static void +image_transform_ini_end(PNG_CONST image_transform *this, + transform_display *that) +{ + UNUSED(this) + UNUSED(that) +} + +static void +image_transform_set_end(PNG_CONST image_transform *this, + transform_display *that, png_structp pp, png_infop pi) +{ + UNUSED(this) + UNUSED(that) + UNUSED(pp) + UNUSED(pi) +} + +/* At the end of the list recalculate the output image pixel value from the + * double precision values set up by the preceding 'mod' calls: + */ +static unsigned int +sample_scale(double sample_value, unsigned int scale) +{ + sample_value = floor(sample_value * scale + .5); + + /* Return NaN as 0: */ + if (!(sample_value > 0)) + sample_value = 0; + else if (sample_value > scale) + sample_value = scale; + + return (unsigned int)sample_value; +} + +static void +image_transform_mod_end(PNG_CONST image_transform *this, image_pixel *that, + png_structp pp, PNG_CONST transform_display *display) +{ + PNG_CONST unsigned int scale = (1U<sample_depth)-1; + + UNUSED(this) + UNUSED(pp) + UNUSED(display) + + /* At the end recalculate the digitized red green and blue values according + * to the current sample_depth of the pixel. + * + * The sample value is simply scaled to the maximum, checking for over + * and underflow (which can both happen for some image transforms, + * including simple size scaling, though libpng doesn't do that at present. + */ + that->red = sample_scale(that->redf, scale); + + /* The error value is increased, at the end, according to the lowest sBIT + * value seen. Common sense tells us that the intermediate integer + * representations are no more accurate than +/- 0.5 in the integral values, + * the sBIT allows the implementation to be worse than this. In addition the + * PNG specification actually permits any error within the range (-1..+1), + * but that is ignored here. Instead the final digitized value is compared, + * below to the digitized value of the error limits - this has the net effect + * of allowing (almost) +/-1 in the output value. It's difficult to see how + * any algorithm that digitizes intermediate results can be more accurate. + */ + that->rede += 1./(2*((1U<red_sBIT)-1)); + + if (that->colour_type & PNG_COLOR_MASK_COLOR) + { + that->green = sample_scale(that->greenf, scale); + that->blue = sample_scale(that->bluef, scale); + that->greene += 1./(2*((1U<green_sBIT)-1)); + that->bluee += 1./(2*((1U<blue_sBIT)-1)); + } + else + { + that->blue = that->green = that->red; + that->bluef = that->greenf = that->redf; + that->bluee = that->greene = that->rede; + } + + if ((that->colour_type & PNG_COLOR_MASK_ALPHA) || + that->colour_type == PNG_COLOR_TYPE_PALETTE) + { + that->alpha = sample_scale(that->alphaf, scale); + that->alphae += 1./(2*((1U<alpha_sBIT)-1)); + } + else + { + that->alpha = scale; /* opaque */ + that->alpha = 1; /* Override this. */ + that->alphae = 0; /* It's exact ;-) */ + } +} + +/* Static 'end' structure: */ +static image_transform image_transform_end = +{ + "(end)", /* name */ + 1, /* enable */ + 0, /* list */ + 0, /* global_use */ + 0, /* local_use */ + 0, /* next */ + image_transform_ini_end, + image_transform_set_end, + image_transform_mod_end, + 0 /* never called, I want it to crash if it is! */ +}; + +/* Reader callbacks and implementations, where they differ from the standard + * ones. + */ +static void +transform_display_init(transform_display *dp, png_modifier *pm, png_uint_32 id, + PNG_CONST image_transform *transform_list) +{ + memset(dp, 0, sizeof dp); + + /* Standard fields */ + standard_display_init(&dp->this, &pm->this, id, 0/*do_interlace*/, + pm->use_update_info); + + /* Parameter fields */ + dp->pm = pm; + dp->transform_list = transform_list; + + /* Local variable fields */ + dp->output_colour_type = 255; /* invalid */ + dp->output_bit_depth = 255; /* invalid */ +} + +static void +transform_info_imp(transform_display *dp, png_structp pp, png_infop pi) +{ + /* Reuse the standard stuff as appropriate. */ + standard_info_part1(&dp->this, pp, pi); + + /* Now set the list of transforms. */ + dp->transform_list->set(dp->transform_list, dp, pp, pi); + + /* Update the info structure for these transforms: */ + { + int i = dp->this.use_update_info; + /* Always do one call, even if use_update_info is 0. */ + do + png_read_update_info(pp, pi); + while (--i > 0); + } + + /* And get the output information into the standard_display */ + standard_info_part2(&dp->this, pp, pi, 1/*images*/); + + /* Plus the extra stuff we need for the transform tests: */ + dp->output_colour_type = png_get_color_type(pp, pi); + dp->output_bit_depth = png_get_bit_depth(pp, pi); + + /* Validate the combination of colour type and bit depth that we are getting + * out of libpng; the semantics of something not in the PNG spec are, at + * best, unclear. + */ + switch (dp->output_colour_type) + { + case PNG_COLOR_TYPE_PALETTE: + if (dp->output_bit_depth > 8) goto error; + /*FALL THROUGH*/ + case PNG_COLOR_TYPE_GRAY: + if (dp->output_bit_depth == 1 || dp->output_bit_depth == 2 || + dp->output_bit_depth == 4) + break; + /*FALL THROUGH*/ + default: + if (dp->output_bit_depth == 8 || dp->output_bit_depth == 16) + break; + /*FALL THROUGH*/ + error: + { + char message[128]; + size_t pos; + + pos = safecat(message, sizeof message, 0, + "invalid final bit depth: colour type("); + pos = safecatn(message, sizeof message, pos, dp->output_colour_type); + pos = safecat(message, sizeof message, pos, ") with bit depth: "); + pos = safecatn(message, sizeof message, pos, dp->output_bit_depth); + + png_error(pp, message); + } + } + + /* Use a test pixel to check that the output agrees with what we expect - + * this avoids running the whole test if the output is unexpected. + */ + { + image_pixel test_pixel; + + memset(&test_pixel, 0, sizeof test_pixel); + test_pixel.colour_type = dp->this.colour_type; /* input */ + test_pixel.bit_depth = dp->this.bit_depth; + if (test_pixel.colour_type == PNG_COLOR_TYPE_PALETTE) + test_pixel.sample_depth = 8; + else + test_pixel.sample_depth = test_pixel.bit_depth; + /* Don't need sBIT here, but it must be set to non-zero to avoid + * arithmetic overflows. + */ + test_pixel.have_tRNS = dp->this.is_transparent; + test_pixel.red_sBIT = test_pixel.green_sBIT = test_pixel.blue_sBIT = + test_pixel.alpha_sBIT = test_pixel.sample_depth; + + dp->transform_list->mod(dp->transform_list, &test_pixel, pp, dp); + + if (test_pixel.colour_type != dp->output_colour_type) + { + char message[128]; + size_t pos = safecat(message, sizeof message, 0, "colour type "); + + pos = safecatn(message, sizeof message, pos, dp->output_colour_type); + pos = safecat(message, sizeof message, pos, " expected "); + pos = safecatn(message, sizeof message, pos, test_pixel.colour_type); + + png_error(pp, message); + } + + if (test_pixel.bit_depth != dp->output_bit_depth) + { + char message[128]; + size_t pos = safecat(message, sizeof message, 0, "bit depth "); + + pos = safecatn(message, sizeof message, pos, dp->output_bit_depth); + pos = safecat(message, sizeof message, pos, " expected "); + pos = safecatn(message, sizeof message, pos, test_pixel.bit_depth); + + png_error(pp, message); + } + + /* If both bit depth and colour type are correct check the sample depth. + * I believe these are both internal errors. + */ + if (test_pixel.colour_type == PNG_COLOR_TYPE_PALETTE) + { + if (test_pixel.sample_depth != 8) /* oops - internal error! */ + png_error(pp, "pngvalid: internal: palette sample depth not 8"); + } + else if (test_pixel.sample_depth != dp->output_bit_depth) + { + char message[128]; + size_t pos = safecat(message, sizeof message, 0, + "internal: sample depth "); + + pos = safecatn(message, sizeof message, pos, dp->output_bit_depth); + pos = safecat(message, sizeof message, pos, " expected "); + pos = safecatn(message, sizeof message, pos, test_pixel.sample_depth); + + png_error(pp, message); + } + } +} + +static void +transform_info(png_structp pp, png_infop pi) +{ + transform_info_imp(voidcast(transform_display*, png_get_progressive_ptr(pp)), + pp, pi); +} + +static void +transform_range_check(png_structp pp, unsigned int r, unsigned int g, + unsigned int b, unsigned int a, unsigned int in_digitized, double in, + unsigned int out, png_byte sample_depth, double err, double limit, + PNG_CONST char *name, double digitization_error) +{ + /* Compare the scaled, digitzed, values of our local calculation (in+-err) + * with the digitized values libpng produced; 'sample_depth' is the actual + * digitization depth of the libpng output colors (the bit depth except for + * palette images where it is always 8.) The check on 'err' is to detect + * internal errors in pngvalid itself. + */ + unsigned int max = (1U< limit || !(out >= in_min && out <= in_max)) + { + char message[256]; + size_t pos; + + pos = safecat(message, sizeof message, 0, name); + pos = safecat(message, sizeof message, pos, " output value error: rgba("); + pos = safecatn(message, sizeof message, pos, r); + pos = safecat(message, sizeof message, pos, ","); + pos = safecatn(message, sizeof message, pos, g); + pos = safecat(message, sizeof message, pos, ","); + pos = safecatn(message, sizeof message, pos, b); + pos = safecat(message, sizeof message, pos, ","); + pos = safecatn(message, sizeof message, pos, a); + pos = safecat(message, sizeof message, pos, "): "); + pos = safecatn(message, sizeof message, pos, out); + pos = safecat(message, sizeof message, pos, " expected: "); + pos = safecatn(message, sizeof message, pos, in_digitized); + pos = safecat(message, sizeof message, pos, " ("); + pos = safecatd(message, sizeof message, pos, (in-err)*max, 3); + pos = safecat(message, sizeof message, pos, ".."); + pos = safecatd(message, sizeof message, pos, (in+err)*max, 3); + pos = safecat(message, sizeof message, pos, ")"); + + png_error(pp, message); + } +} + +static void +transform_image_validate(transform_display *dp, png_structp pp, png_infop pi) +{ + /* Constants for the loop below: */ + PNG_CONST png_store* PNG_CONST ps = dp->this.ps; + PNG_CONST png_byte in_ct = dp->this.colour_type; + PNG_CONST png_byte in_bd = dp->this.bit_depth; + PNG_CONST png_uint_32 w = dp->this.w; + PNG_CONST png_uint_32 h = dp->this.h; + PNG_CONST png_byte out_ct = dp->output_colour_type; + PNG_CONST png_byte out_bd = dp->output_bit_depth; + PNG_CONST png_byte sample_depth = (png_byte)(out_ct == + PNG_COLOR_TYPE_PALETTE ? 8 : out_bd); + PNG_CONST png_byte red_sBIT = dp->this.red_sBIT; + PNG_CONST png_byte green_sBIT = dp->this.green_sBIT; + PNG_CONST png_byte blue_sBIT = dp->this.blue_sBIT; + PNG_CONST png_byte alpha_sBIT = dp->this.alpha_sBIT; + PNG_CONST int have_tRNS = dp->this.is_transparent; + double digitization_error; + + store_palette out_palette; + png_uint_32 y; + + UNUSED(pi) + + /* Check for row overwrite errors */ + store_image_check(dp->this.ps, pp, 0); + + /* Read the palette corresponding to the output if the output colour type + * indicates a palette, othewise set out_palette to garbage. + */ + if (out_ct == PNG_COLOR_TYPE_PALETTE) + { + /* Validate that the palette count itself has not changed - this is not + * expected. + */ + int npalette = (-1); + + (void)read_palette(out_palette, &npalette, pp, pi); + if (npalette != dp->this.npalette) + png_error(pp, "unexpected change in palette size"); + + digitization_error = .5; + } + else + { + png_byte in_sample_depth; + + memset(out_palette, 0x5e, sizeof out_palette); + + /* assume-8-bit-calculations means assume that if the input has 8 bit + * (or less) samples and the output has 16 bit samples the calculations + * will be done with 8 bit precision, not 16. + * + * TODO: fix this in libpng; png_set_expand_16 should cause 16 bit + * calculations to be used throughout. + */ + if (in_ct == PNG_COLOR_TYPE_PALETTE || in_bd < 16) + in_sample_depth = 8; + else + in_sample_depth = in_bd; + + if (sample_depth != 16 || in_sample_depth > 8 || + !dp->pm->calculations_use_input_precision) + digitization_error = .5; + + /* Else errors are at 8 bit precision, scale .5 in 8 bits to the 16 bits: + */ + else + digitization_error = .5 * 257; + } + + for (y=0; ythis.palette); + + in_pixel.red_sBIT = red_sBIT; + in_pixel.green_sBIT = green_sBIT; + in_pixel.blue_sBIT = blue_sBIT; + in_pixel.alpha_sBIT = alpha_sBIT; + in_pixel.have_tRNS = have_tRNS; + + /* For error detection, below. */ + r = in_pixel.red; + g = in_pixel.green; + b = in_pixel.blue; + a = in_pixel.alpha; + + dp->transform_list->mod(dp->transform_list, &in_pixel, pp, dp); + + /* Read the output pixel and compare it to what we got, we don't + * use the error field here, so no need to update sBIT. + */ + image_pixel_init(&out_pixel, pRow, out_ct, out_bd, x, out_palette); + + /* We don't expect changes to the index here even if the bit depth is + * changed. + */ + if (in_ct == PNG_COLOR_TYPE_PALETTE && + out_ct == PNG_COLOR_TYPE_PALETTE) + { + if (in_pixel.palette_index != out_pixel.palette_index) + png_error(pp, "unexpected transformed palette index"); + } + + /* Check the colours for palette images too - in fact the palette could + * be separately verified itself in most cases. + */ + if (in_pixel.red != out_pixel.red) + transform_range_check(pp, r, g, b, a, in_pixel.red, in_pixel.redf, + out_pixel.red, sample_depth, in_pixel.rede, + dp->pm->limit + 1./(2*((1U<pm->limit + 1./(2*((1U<pm->limit + 1./(2*((1U<pm->limit + 1./(2*((1U<this.ps->validated = 1; +} + +static void +transform_end(png_structp pp, png_infop pi) +{ + transform_display *dp = voidcast(transform_display*, + png_get_progressive_ptr(pp)); + + if (!dp->this.speed) + transform_image_validate(dp, pp, pi); + else + dp->this.ps->validated = 1; +} + +/* A single test run. */ +static void +transform_test(png_modifier *pmIn, PNG_CONST png_uint_32 idIn, + PNG_CONST image_transform* transform_listIn, PNG_CONST char * volatile name) +{ + transform_display d; + context(&pmIn->this, fault); + + transform_display_init(&d, pmIn, idIn, transform_listIn); + + Try + { + size_t pos = 0; + png_structp pp; + png_infop pi; + char full_name[256]; + + /* Make sure the encoding fields are correct and enter the required + * modifications. + */ + transform_set_encoding(&d); + + /* Add any modifications required by the transform list. */ + d.transform_list->ini(d.transform_list, &d); + + /* Add the color space information, if any, to the name. */ + pos = safecat(full_name, sizeof full_name, pos, name); + pos = safecat_current_encoding(full_name, sizeof full_name, pos, d.pm); + + /* Get a png_struct for reading the image. */ + pp = set_modifier_for_read(d.pm, &pi, d.this.id, full_name); + standard_palette_init(&d.this); + +# if 0 + /* Logging (debugging only) */ + { + char buffer[256]; + + (void)store_message(&d.pm->this, pp, buffer, sizeof buffer, 0, + "running test"); + + fprintf(stderr, "%s\n", buffer); + } +# endif + + /* Introduce the correct read function. */ + if (d.pm->this.progressive) + { + /* Share the row function with the standard implementation. */ + png_set_progressive_read_fn(pp, &d, transform_info, progressive_row, + transform_end); + + /* Now feed data into the reader until we reach the end: */ + modifier_progressive_read(d.pm, pp, pi); + } + else + { + /* modifier_read expects a png_modifier* */ + png_set_read_fn(pp, d.pm, modifier_read); + + /* Check the header values: */ + png_read_info(pp, pi); + + /* Process the 'info' requirements. Only one image is generated */ + transform_info_imp(&d, pp, pi); + + sequential_row(&d.this, pp, pi, -1, 0); + + if (!d.this.speed) + transform_image_validate(&d, pp, pi); + else + d.this.ps->validated = 1; + } + + modifier_reset(d.pm); + } + + Catch(fault) + { + modifier_reset((png_modifier*)fault); + } +} + +/* The transforms: */ +#define ITSTRUCT(name) image_transform_##name +#define ITDATA(name) image_transform_data_##name +#define image_transform_ini image_transform_default_ini +#define IT(name)\ +static image_transform ITSTRUCT(name) =\ +{\ + #name,\ + 1, /*enable*/\ + &PT, /*list*/\ + 0, /*global_use*/\ + 0, /*local_use*/\ + 0, /*next*/\ + image_transform_ini,\ + image_transform_png_set_##name##_set,\ + image_transform_png_set_##name##_mod,\ + image_transform_png_set_##name##_add\ +} +#define PT ITSTRUCT(end) /* stores the previous transform */ + +/* To save code: */ +static void +image_transform_default_ini(PNG_CONST image_transform *this, + transform_display *that) +{ + this->next->ini(this->next, that); +} + +static int +image_transform_default_add(image_transform *this, + PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) +{ + UNUSED(colour_type) + UNUSED(bit_depth) + + this->next = *that; + *that = this; + + return 1; +} + +#ifdef PNG_READ_EXPAND_SUPPORTED +/* png_set_palette_to_rgb */ +static void +image_transform_png_set_palette_to_rgb_set(PNG_CONST image_transform *this, + transform_display *that, png_structp pp, png_infop pi) +{ + png_set_palette_to_rgb(pp); + this->next->set(this->next, that, pp, pi); +} + +static void +image_transform_png_set_palette_to_rgb_mod(PNG_CONST image_transform *this, + image_pixel *that, png_structp pp, PNG_CONST transform_display *display) +{ + if (that->colour_type == PNG_COLOR_TYPE_PALETTE) + image_pixel_convert_PLTE(that); + + this->next->mod(this->next, that, pp, display); +} + +static int +image_transform_png_set_palette_to_rgb_add(image_transform *this, + PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) +{ + UNUSED(bit_depth) + + this->next = *that; + *that = this; + + return colour_type == PNG_COLOR_TYPE_PALETTE; +} + +IT(palette_to_rgb); +#undef PT +#define PT ITSTRUCT(palette_to_rgb) +#endif /* PNG_READ_EXPAND_SUPPORTED */ + +#ifdef PNG_READ_EXPAND_SUPPORTED +/* png_set_tRNS_to_alpha */ +static void +image_transform_png_set_tRNS_to_alpha_set(PNG_CONST image_transform *this, + transform_display *that, png_structp pp, png_infop pi) +{ + png_set_tRNS_to_alpha(pp); + this->next->set(this->next, that, pp, pi); +} + +static void +image_transform_png_set_tRNS_to_alpha_mod(PNG_CONST image_transform *this, + image_pixel *that, png_structp pp, PNG_CONST transform_display *display) +{ + /* LIBPNG BUG: this always forces palette images to RGB. */ + if (that->colour_type == PNG_COLOR_TYPE_PALETTE) + image_pixel_convert_PLTE(that); + + /* This effectively does an 'expand' only if there is some transparency to + * convert to an alpha channel. + */ + if (that->have_tRNS) + image_pixel_add_alpha(that, &display->this); + + /* LIBPNG BUG: otherwise libpng still expands to 8 bits! */ + else + { + if (that->bit_depth < 8) + that->bit_depth =8; + if (that->sample_depth < 8) + that->sample_depth = 8; + } + + this->next->mod(this->next, that, pp, display); +} + +static int +image_transform_png_set_tRNS_to_alpha_add(image_transform *this, + PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) +{ + UNUSED(bit_depth) + + this->next = *that; + *that = this; + + /* We don't know yet whether there will be a tRNS chunk, but we know that + * this transformation should do nothing if there already is an alpha + * channel. + */ + return (colour_type & PNG_COLOR_MASK_ALPHA) == 0; +} + +IT(tRNS_to_alpha); +#undef PT +#define PT ITSTRUCT(tRNS_to_alpha) +#endif /* PNG_READ_EXPAND_SUPPORTED */ + +#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED +/* png_set_gray_to_rgb */ +static void +image_transform_png_set_gray_to_rgb_set(PNG_CONST image_transform *this, + transform_display *that, png_structp pp, png_infop pi) +{ + png_set_gray_to_rgb(pp); + this->next->set(this->next, that, pp, pi); +} + +static void +image_transform_png_set_gray_to_rgb_mod(PNG_CONST image_transform *this, + image_pixel *that, png_structp pp, PNG_CONST transform_display *display) +{ + /* NOTE: we can actually pend the tRNS processing at this point because we + * can correctly recognize the original pixel value even though we have + * mapped the one gray channel to the three RGB ones, but in fact libpng + * doesn't do this, so we don't either. + */ + if ((that->colour_type & PNG_COLOR_MASK_COLOR) == 0 && that->have_tRNS) + image_pixel_add_alpha(that, &display->this); + + /* Simply expand the bit depth and alter the colour type as required. */ + if (that->colour_type == PNG_COLOR_TYPE_GRAY) + { + /* RGB images have a bit depth at least equal to '8' */ + if (that->bit_depth < 8) + that->sample_depth = that->bit_depth = 8; + + /* And just changing the colour type works here because the green and blue + * channels are being maintained in lock-step with the red/gray: + */ + that->colour_type = PNG_COLOR_TYPE_RGB; + } + + else if (that->colour_type == PNG_COLOR_TYPE_GRAY_ALPHA) + that->colour_type = PNG_COLOR_TYPE_RGB_ALPHA; + + this->next->mod(this->next, that, pp, display); +} + +static int +image_transform_png_set_gray_to_rgb_add(image_transform *this, + PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) +{ + UNUSED(bit_depth) + + this->next = *that; + *that = this; + + return (colour_type & PNG_COLOR_MASK_COLOR) == 0; +} + +IT(gray_to_rgb); +#undef PT +#define PT ITSTRUCT(gray_to_rgb) +#endif /* PNG_READ_GRAY_TO_RGB_SUPPORTED */ + +#ifdef PNG_READ_EXPAND_SUPPORTED +/* png_set_expand */ +static void +image_transform_png_set_expand_set(PNG_CONST image_transform *this, + transform_display *that, png_structp pp, png_infop pi) +{ + png_set_expand(pp); + this->next->set(this->next, that, pp, pi); +} + +static void +image_transform_png_set_expand_mod(PNG_CONST image_transform *this, + image_pixel *that, png_structp pp, PNG_CONST transform_display *display) +{ + /* The general expand case depends on what the colour type is: */ + if (that->colour_type == PNG_COLOR_TYPE_PALETTE) + image_pixel_convert_PLTE(that); + else if (that->bit_depth < 8) /* grayscale */ + that->sample_depth = that->bit_depth = 8; + + if (that->have_tRNS) + image_pixel_add_alpha(that, &display->this); + + this->next->mod(this->next, that, pp, display); +} + +static int +image_transform_png_set_expand_add(image_transform *this, + PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) +{ + UNUSED(bit_depth) + + this->next = *that; + *that = this; + + /* 'expand' should do nothing for RGBA or GA input - no tRNS and the bit + * depth is at least 8 already. + */ + return (colour_type & PNG_COLOR_MASK_ALPHA) == 0; +} + +IT(expand); +#undef PT +#define PT ITSTRUCT(expand) +#endif /* PNG_READ_EXPAND_SUPPORTED */ + +#ifdef PNG_READ_EXPAND_SUPPORTED +/* png_set_expand_gray_1_2_4_to_8 + * LIBPNG BUG: this just does an 'expand' + */ +static void +image_transform_png_set_expand_gray_1_2_4_to_8_set( + PNG_CONST image_transform *this, transform_display *that, png_structp pp, + png_infop pi) +{ + png_set_expand_gray_1_2_4_to_8(pp); + this->next->set(this->next, that, pp, pi); +} + +static void +image_transform_png_set_expand_gray_1_2_4_to_8_mod( + PNG_CONST image_transform *this, image_pixel *that, png_structp pp, + PNG_CONST transform_display *display) +{ + image_transform_png_set_expand_mod(this, that, pp, display); +} + +static int +image_transform_png_set_expand_gray_1_2_4_to_8_add(image_transform *this, + PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) +{ + return image_transform_png_set_expand_add(this, that, colour_type, + bit_depth); +} + +IT(expand_gray_1_2_4_to_8); +#undef PT +#define PT ITSTRUCT(expand_gray_1_2_4_to_8) +#endif /* PNG_READ_EXPAND_SUPPORTED */ + +#ifdef PNG_READ_EXPAND_16_SUPPORTED +/* png_set_expand_16 */ +static void +image_transform_png_set_expand_16_set(PNG_CONST image_transform *this, + transform_display *that, png_structp pp, png_infop pi) +{ + png_set_expand_16(pp); + this->next->set(this->next, that, pp, pi); +} + +static void +image_transform_png_set_expand_16_mod(PNG_CONST image_transform *this, + image_pixel *that, png_structp pp, PNG_CONST transform_display *display) +{ + /* Expect expand_16 to expand everything to 16 bits as a result of also + * causing 'expand' to happen. + */ + if (that->colour_type == PNG_COLOR_TYPE_PALETTE) + image_pixel_convert_PLTE(that); + + if (that->have_tRNS) + image_pixel_add_alpha(that, &display->this); + + if (that->bit_depth < 16) + that->sample_depth = that->bit_depth = 16; + + this->next->mod(this->next, that, pp, display); +} + +static int +image_transform_png_set_expand_16_add(image_transform *this, + PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) +{ + UNUSED(colour_type) + + this->next = *that; + *that = this; + + /* expand_16 does something unless the bit depth is already 16. */ + return bit_depth < 16; +} + +IT(expand_16); +#undef PT +#define PT ITSTRUCT(expand_16) +#endif /* PNG_READ_EXPAND_16_SUPPORTED */ + +#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED /* API added in 1.5.4 */ +/* png_set_scale_16 */ +static void +image_transform_png_set_scale_16_set(PNG_CONST image_transform *this, + transform_display *that, png_structp pp, png_infop pi) +{ + png_set_scale_16(pp); + this->next->set(this->next, that, pp, pi); +} + +static void +image_transform_png_set_scale_16_mod(PNG_CONST image_transform *this, + image_pixel *that, png_structp pp, PNG_CONST transform_display *display) +{ + if (that->bit_depth == 16) + { + that->sample_depth = that->bit_depth = 8; + if (that->red_sBIT > 8) that->red_sBIT = 8; + if (that->green_sBIT > 8) that->green_sBIT = 8; + if (that->blue_sBIT > 8) that->blue_sBIT = 8; + if (that->alpha_sBIT > 8) that->alpha_sBIT = 8; + } + + this->next->mod(this->next, that, pp, display); +} + +static int +image_transform_png_set_scale_16_add(image_transform *this, + PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) +{ + UNUSED(colour_type) + + this->next = *that; + *that = this; + + return bit_depth > 8; +} + +IT(scale_16); +#undef PT +#define PT ITSTRUCT(scale_16) +#endif /* PNG_READ_SCALE_16_TO_8_SUPPORTED (1.5.4 on) */ + +#ifdef PNG_READ_16_TO_8_SUPPORTED /* the default before 1.5.4 */ +/* png_set_strip_16 */ +static void +image_transform_png_set_strip_16_set(PNG_CONST image_transform *this, + transform_display *that, png_structp pp, png_infop pi) +{ + png_set_strip_16(pp); + this->next->set(this->next, that, pp, pi); +} + +static void +image_transform_png_set_strip_16_mod(PNG_CONST image_transform *this, + image_pixel *that, png_structp pp, PNG_CONST transform_display *display) +{ + if (that->bit_depth == 16) + { + that->sample_depth = that->bit_depth = 8; + if (that->red_sBIT > 8) that->red_sBIT = 8; + if (that->green_sBIT > 8) that->green_sBIT = 8; + if (that->blue_sBIT > 8) that->blue_sBIT = 8; + if (that->alpha_sBIT > 8) that->alpha_sBIT = 8; + + /* Prior to 1.5.4 png_set_strip_16 would use an 'accurate' method if this + * configuration option is set. From 1.5.4 the flag is never set and the + * 'scale' API (above) must be used. + */ +# ifdef PNG_READ_ACCURATE_SCALE_SUPPORTED +# if PNG_LIBPNG_VER >= 10504 +# error PNG_READ_ACCURATE_SCALE should not be set +# endif + + /* The strip 16 algorithm drops the low 8 bits rather than calculating + * 1/257, so we need to adjust the permitted errors appropriately: + * Notice that this is only relevant prior to the addition of the + * png_set_scale_16 API in 1.5.4 (but 1.5.4+ always defines the above!) + */ + { + PNG_CONST double d = (255-128.5)/65535; + that->rede += d; + that->greene += d; + that->bluee += d; + that->alphae += d; + } +# endif + } + + this->next->mod(this->next, that, pp, display); +} + +static int +image_transform_png_set_strip_16_add(image_transform *this, + PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) +{ + UNUSED(colour_type) + + this->next = *that; + *that = this; + + return bit_depth > 8; +} + +IT(strip_16); +#undef PT +#define PT ITSTRUCT(strip_16) +#endif /* PNG_READ_16_TO_8_SUPPORTED */ + +#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED +/* png_set_strip_alpha */ +static void +image_transform_png_set_strip_alpha_set(PNG_CONST image_transform *this, + transform_display *that, png_structp pp, png_infop pi) +{ + png_set_strip_alpha(pp); + this->next->set(this->next, that, pp, pi); +} + +static void +image_transform_png_set_strip_alpha_mod(PNG_CONST image_transform *this, + image_pixel *that, png_structp pp, PNG_CONST transform_display *display) +{ + if (that->colour_type == PNG_COLOR_TYPE_GRAY_ALPHA) + that->colour_type = PNG_COLOR_TYPE_GRAY; + else if (that->colour_type == PNG_COLOR_TYPE_RGB_ALPHA) + that->colour_type = PNG_COLOR_TYPE_RGB; + + that->have_tRNS = 0; + that->alphaf = 1; + + this->next->mod(this->next, that, pp, display); +} + +static int +image_transform_png_set_strip_alpha_add(image_transform *this, + PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) +{ + UNUSED(bit_depth) + + this->next = *that; + *that = this; + + return (colour_type & PNG_COLOR_MASK_ALPHA) != 0; +} + +IT(strip_alpha); +#undef PT +#define PT ITSTRUCT(strip_alpha) +#endif /* PNG_READ_STRIP_ALPHA_SUPPORTED */ + +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED +/* png_set_rgb_to_gray(png_structp, int err_action, double red, double green) + * png_set_rgb_to_gray_fixed(png_structp, int err_action, png_fixed_point red, + * png_fixed_point green) + * png_get_rgb_to_gray_status + * + * The 'default' test here uses values known to be used inside libpng: + * + * red: 6968 + * green: 23434 + * blue: 2366 + * + * These values are being retained for compatibility, along with the somewhat + * broken truncation calculation in the fast-and-inaccurate code path. Older + * versions of libpng will fail the accuracy tests below because they use the + * truncation algorithm everywhere. + */ +#define data ITDATA(rgb_to_gray) +static struct +{ + double gamma; /* File gamma to use in processing */ + + /* The following are the parameters for png_set_rgb_to_gray: */ +# ifdef PNG_FLOATING_POINT_SUPPORTED + double red_to_set; + double green_to_set; +# else + png_fixed_point red_to_set; + png_fixed_point green_to_set; +# endif + + /* The actual coefficients: */ + double red_coefficient; + double green_coefficient; + double blue_coefficient; + + /* Set if the coeefficients have been overridden. */ + int coefficients_overridden; +} data; + +#undef image_transform_ini +#define image_transform_ini image_transform_png_set_rgb_to_gray_ini +static void +image_transform_png_set_rgb_to_gray_ini(PNG_CONST image_transform *this, + transform_display *that) +{ + png_modifier *pm = that->pm; + PNG_CONST color_encoding *e = pm->current_encoding; + + UNUSED(this) + + /* Since we check the encoding this flag must be set: */ + pm->test_uses_encoding = 1; + + /* If 'e' is not NULL chromaticity information is present and either a cHRM + * or an sRGB chunk will be inserted. + */ + if (e != 0) + { + /* Coefficients come from the encoding, but may need to be normalized to a + * white point Y of 1.0 + */ + PNG_CONST double whiteY = e->red.Y + e->green.Y + e->blue.Y; + + data.red_coefficient = e->red.Y; + data.green_coefficient = e->green.Y; + data.blue_coefficient = e->blue.Y; + + if (whiteY != 1) + { + data.red_coefficient /= whiteY; + data.green_coefficient /= whiteY; + data.blue_coefficient /= whiteY; + } + } + + else + { + /* The default (built in) coeffcients, as above: */ + data.red_coefficient = 6968 / 32768.; + data.green_coefficient = 23434 / 32768.; + data.blue_coefficient = 2366 / 32768.; + } + + data.gamma = pm->current_gamma; + + /* If not set then the calculations assume linear encoding (implicitly): */ + if (data.gamma == 0) + data.gamma = 1; + + /* The arguments to png_set_rgb_to_gray can override the coefficients implied + * by the color space encoding. If doing exhaustive checks do the override + * in each case, otherwise do it randomly. + */ + if (pm->test_exhaustive) + { + /* First time in coefficients_overridden is 0, the following sets it to 1, + * so repeat if it is set. If a test fails this may mean we subsequently + * skip a non-override test, ignore that. + */ + data.coefficients_overridden = !data.coefficients_overridden; + pm->repeat = data.coefficients_overridden != 0; + } + + else + data.coefficients_overridden = random_choice(); + + if (data.coefficients_overridden) + { + /* These values override the color encoding defaults, simply use random + * numbers. + */ + png_uint_32 ru; + double total; + + RANDOMIZE(ru); + data.green_coefficient = total = (ru & 0xffff) / 65535.; + ru >>= 16; + data.red_coefficient = (1 - total) * (ru & 0xffff) / 65535.; + total += data.red_coefficient; + data.blue_coefficient = 1 - total; + +# ifdef PNG_FLOATING_POINT_SUPPORTED + data.red_to_set = data.red_coefficient; + data.green_to_set = data.green_coefficient; +# else + data.red_to_set = fix(data.red_coefficient); + data.green_to_set = fix(data.green_coefficient); +# endif + + /* The following just changes the error messages: */ + pm->encoding_ignored = 1; + } + + else + { + data.red_to_set = -1; + data.green_to_set = -1; + } + + /* Adjust the error limit in the png_modifier because of the larger errors + * produced in the digitization during the gamma handling. + */ + if (data.gamma != 1) /* Use gamma tables */ + { + if (that->this.bit_depth == 16 || pm->assume_16_bit_calculations) + { + /* The 16 bit case ends up producing a maximum error of about + * +/-5 in 65535, allow for +/-8 with the given gamma. + */ + that->pm->limit += pow(8./65535, data.gamma); + } + + else + { + /* Rounding to 8 bits in the linear space causes massive errors which + * will trigger the error check in transform_range_check. Fix that + * here by taking the gamma encoding into account. + */ + that->pm->limit += pow(1./255, data.gamma); + } + } + + else + { + /* With no gamma correction a large error comes from the truncation of the + * calculation in the 8 bit case, allow for that here. + */ + if (that->this.bit_depth != 16) + that->pm->limit += 4E-3; + } +} + +static void +image_transform_png_set_rgb_to_gray_set(PNG_CONST image_transform *this, + transform_display *that, png_structp pp, png_infop pi) +{ + PNG_CONST int error_action = 1; /* no error, no defines in png.h */ + +# ifdef PNG_FLOATING_POINT_SUPPORTED + png_set_rgb_to_gray(pp, error_action, data.red_to_set, data.green_to_set); +# else + png_set_rgb_to_gray_fixed(pp, error_action, data.red_to_set, + data.green_to_set); +# endif + +# ifdef PNG_READ_cHRM_SUPPORTED + if (that->pm->current_encoding != 0) + { + /* We have an encoding so a cHRM chunk may have been set; if so then + * check that the libpng APIs give the correct (X,Y,Z) values within + * some margin of error for the round trip through the chromaticity + * form. + */ +# ifdef PNG_FLOATING_POINT_SUPPORTED +# define API_function png_get_cHRM_XYZ +# define API_form "FP" +# define API_type double +# define API_cvt(x) (x) +# else +# define API_function png_get_cHRM_XYZ_fixed +# define API_form "fixed" +# define API_type png_fixed_point +# define API_cvt(x) ((double)(x)/PNG_FP_1) +# endif + + API_type rX, gX, bX; + API_type rY, gY, bY; + API_type rZ, gZ, bZ; + + if ((API_function(pp, pi, &rX, &rY, &rZ, &gX, &gY, &gZ, &bX, &bY, &bZ) + & PNG_INFO_cHRM) != 0) + { + double maxe; + PNG_CONST char *el; + color_encoding e, o; + + /* Expect libpng to return a normalized result, but the original + * color space encoding may not be normalized. + */ + modifier_current_encoding(that->pm, &o); + normalize_color_encoding(&o); + + /* Sanity check the pngvalid code - the coefficients should match + * the normalized Y values of the encoding unless they were + * overridden. + */ + if (data.red_to_set == -1 && data.green_to_set == -1 && + (fabs(o.red.Y - data.red_coefficient) > DBL_EPSILON || + fabs(o.green.Y - data.green_coefficient) > DBL_EPSILON || + fabs(o.blue.Y - data.blue_coefficient) > DBL_EPSILON)) + png_error(pp, "internal pngvalid cHRM coefficient error"); + + /* Generate a colour space encoding. */ + e.gamma = o.gamma; /* not used */ + e.red.X = API_cvt(rX); + e.red.Y = API_cvt(rY); + e.red.Z = API_cvt(rZ); + e.green.X = API_cvt(gX); + e.green.Y = API_cvt(gY); + e.green.Z = API_cvt(gZ); + e.blue.X = API_cvt(bX); + e.blue.Y = API_cvt(bY); + e.blue.Z = API_cvt(bZ); + + /* This should match the original one from the png_modifier, within + * the range permitted by the libpng fixed point representation. + */ + maxe = 0; + el = "-"; /* Set to element name with error */ + +# define CHECK(col,x)\ + {\ + double err = fabs(o.col.x - e.col.x);\ + if (err > maxe)\ + {\ + maxe = err;\ + el = #col "(" #x ")";\ + }\ + } + + CHECK(red,X) + CHECK(red,Y) + CHECK(red,Z) + CHECK(green,X) + CHECK(green,Y) + CHECK(green,Z) + CHECK(blue,X) + CHECK(blue,Y) + CHECK(blue,Z) + + /* Here in both fixed and floating cases to check the values read + * from the cHRm chunk. PNG uses fixed point in the cHRM chunk, so + * we can't expect better than +/-.5E-5 on the result, allow 1E-5. + */ + if (maxe >= 1E-5) + { + size_t pos = 0; + char buffer[256]; + + pos = safecat(buffer, sizeof buffer, pos, API_form); + pos = safecat(buffer, sizeof buffer, pos, " cHRM "); + pos = safecat(buffer, sizeof buffer, pos, el); + pos = safecat(buffer, sizeof buffer, pos, " error: "); + pos = safecatd(buffer, sizeof buffer, pos, maxe, 7); + pos = safecat(buffer, sizeof buffer, pos, " "); + /* Print the color space without the gamma value: */ + pos = safecat_color_encoding(buffer, sizeof buffer, pos, &o, 0); + pos = safecat(buffer, sizeof buffer, pos, " -> "); + pos = safecat_color_encoding(buffer, sizeof buffer, pos, &e, 0); + + png_error(pp, buffer); + } + } + } +# endif /* READ_cHRM */ + + this->next->set(this->next, that, pp, pi); +} + +static void +image_transform_png_set_rgb_to_gray_mod(PNG_CONST image_transform *this, + image_pixel *that, png_structp pp, PNG_CONST transform_display *display) +{ + if ((that->colour_type & PNG_COLOR_MASK_COLOR) != 0) + { + double gray, err; + + if (that->colour_type == PNG_COLOR_TYPE_PALETTE) + image_pixel_convert_PLTE(that); + + /* Image now has RGB channels... */ + { + PNG_CONST png_modifier *pm = display->pm; + PNG_CONST unsigned int sample_depth = that->sample_depth; + int isgray; + double r, g, b; + double rlo, rhi, glo, ghi, blo, bhi, graylo, grayhi; + + /* Do this using interval arithmetic, otherwise it is too difficult to + * handle the errors correctly. + * + * To handle the gamma correction work out the upper and lower bounds + * of the digitized value. Assume rounding here - normally the values + * will be identical after this operation if there is only one + * transform, feel free to delete the png_error checks on this below in + * the future (this is just me trying to ensure it works!) + */ + r = rlo = rhi = that->redf; + rlo -= that->rede; + rlo = digitize(pm, rlo, sample_depth, 1/*round*/); + rhi += that->rede; + rhi = digitize(pm, rhi, sample_depth, 1/*round*/); + + g = glo = ghi = that->greenf; + glo -= that->greene; + glo = digitize(pm, glo, sample_depth, 1/*round*/); + ghi += that->greene; + ghi = digitize(pm, ghi, sample_depth, 1/*round*/); + + b = blo = bhi = that->bluef; + blo -= that->bluee; + blo = digitize(pm, blo, sample_depth, 1/*round*/); + bhi += that->greene; + bhi = digitize(pm, bhi, sample_depth, 1/*round*/); + + isgray = r==g && g==b; + + if (data.gamma != 1) + { + PNG_CONST double power = 1/data.gamma; + PNG_CONST double abse = abserr(pm, sample_depth, sample_depth); + + /* 'abse' is the absolute error permitted in linear calculations. It + * is used here to capture the error permitted in the handling + * (undoing) of the gamma encoding. Once again digitization occurs + * to handle the upper and lower bounds of the values. This is + * where the real errors are introduced. + */ + r = pow(r, power); + rlo = digitize(pm, pow(rlo, power)-abse, sample_depth, 1); + rhi = digitize(pm, pow(rhi, power)+abse, sample_depth, 1); + + g = pow(g, power); + glo = digitize(pm, pow(glo, power)-abse, sample_depth, 1); + ghi = digitize(pm, pow(ghi, power)+abse, sample_depth, 1); + + b = pow(b, power); + blo = digitize(pm, pow(blo, power)-abse, sample_depth, 1); + bhi = digitize(pm, pow(bhi, power)+abse, sample_depth, 1); + } + + /* Now calculate the actual gray values. Although the error in the + * coefficients depends on whether they were specified on the command + * line (in which case truncation to 15 bits happened) or not (rounding + * was used) the maxium error in an individual coefficient is always + * 1/32768, because even in the rounding case the requirement that + * coefficients add up to 32768 can cause a larger rounding error. + * + * The only time when rounding doesn't occur in 1.5.5 and later is when + * the non-gamma code path is used for less than 16 bit data. + */ + gray = r * data.red_coefficient + g * data.green_coefficient + + b * data.blue_coefficient; + + { + PNG_CONST int do_round = data.gamma != 1 || sample_depth == 16; + PNG_CONST double ce = 1. / 32768; + + graylo = digitize(pm, rlo * (data.red_coefficient-ce) + + glo * (data.green_coefficient-ce) + + blo * (data.blue_coefficient-ce), sample_depth, do_round); + if (graylo <= 0) + graylo = 0; + + grayhi = digitize(pm, rhi * (data.red_coefficient+ce) + + ghi * (data.green_coefficient+ce) + + bhi * (data.blue_coefficient+ce), sample_depth, do_round); + if (grayhi >= 1) + grayhi = 1; + } + + /* And invert the gamma. */ + if (data.gamma != 1) + { + PNG_CONST double power = data.gamma; + + gray = pow(gray, power); + graylo = digitize(pm, pow(graylo, power), sample_depth, 1); + grayhi = digitize(pm, pow(grayhi, power), sample_depth, 1); + } + + /* Now the error can be calculated. + * + * If r==g==b because there is no overall gamma correction libpng + * currently preserves the original value. + */ + if (isgray) + err = (that->rede + that->greene + that->bluee)/3; + + else + { + err = fabs(grayhi-gray); + if (fabs(gray - graylo) > err) + err = fabs(graylo-gray); + + /* Check that this worked: */ + if (err > display->pm->limit) + { + size_t pos = 0; + char buffer[128]; + + pos = safecat(buffer, sizeof buffer, pos, "rgb_to_gray error "); + pos = safecatd(buffer, sizeof buffer, pos, err, 6); + pos = safecat(buffer, sizeof buffer, pos, " exceeds limit "); + pos = safecatd(buffer, sizeof buffer, pos, + display->pm->limit, 6); + png_error(pp, buffer); + } + } + } + + that->bluef = that->greenf = that->redf = gray; + that->bluee = that->greene = that->rede = err; + + /* The sBIT is the minium of the three colour channel sBITs. */ + if (that->red_sBIT > that->green_sBIT) + that->red_sBIT = that->green_sBIT; + if (that->red_sBIT > that->blue_sBIT) + that->red_sBIT = that->blue_sBIT; + that->blue_sBIT = that->green_sBIT = that->red_sBIT; + + /* And remove the colour bit in the type: */ + if (that->colour_type == PNG_COLOR_TYPE_RGB) + that->colour_type = PNG_COLOR_TYPE_GRAY; + else if (that->colour_type == PNG_COLOR_TYPE_RGB_ALPHA) + that->colour_type = PNG_COLOR_TYPE_GRAY_ALPHA; + } + + this->next->mod(this->next, that, pp, display); +} + +static int +image_transform_png_set_rgb_to_gray_add(image_transform *this, + PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) +{ + UNUSED(bit_depth) + + this->next = *that; + *that = this; + + return (colour_type & PNG_COLOR_MASK_COLOR) != 0; +} + +#undef data +IT(rgb_to_gray); +#undef PT +#define PT ITSTRUCT(rgb_to_gray) +#undef image_transform_ini +#define image_transform_ini image_transform_default_ini +#endif /* PNG_READ_RGB_TO_GRAY_SUPPORTED */ + +#ifdef PNG_READ_BACKGROUND_SUPPORTED +/* png_set_background(png_structp, png_const_color_16p background_color, + * int background_gamma_code, int need_expand, double background_gamma) + * png_set_background_fixed(png_structp, png_const_color_16p background_color, + * int background_gamma_code, int need_expand, + * png_fixed_point background_gamma) + * + * As with rgb_to_gray this ignores the gamma (at present.) +*/ +#define data ITDATA(background) +static image_pixel data; + +static void +image_transform_png_set_background_set(PNG_CONST image_transform *this, + transform_display *that, png_structp pp, png_infop pi) +{ + png_byte colour_type, bit_depth; + png_byte random_bytes[8]; /* 8 bytes - 64 bits - the biggest pixel */ + png_color_16 back; + + /* We need a background colour, because we don't know exactly what transforms + * have been set we have to supply the colour in the original file format and + * so we need to know what that is! The background colour is stored in the + * transform_display. + */ + RANDOMIZE(random_bytes); + + /* Read the random value, for colour type 3 the background colour is actually + * expressed as a 24bit rgb, not an index. + */ + colour_type = that->this.colour_type; + if (colour_type == 3) + { + colour_type = PNG_COLOR_TYPE_RGB; + bit_depth = 8; + } + + else + bit_depth = that->this.bit_depth; + + image_pixel_init(&data, random_bytes, colour_type, + bit_depth, 0/*x*/, 0/*unused: palette*/); + + /* Extract the background colour from this image_pixel, but make sure the + * unused fields of 'back' are garbage. + */ + RANDOMIZE(back); + + if (colour_type & PNG_COLOR_MASK_COLOR) + { + back.red = (png_uint_16)data.red; + back.green = (png_uint_16)data.green; + back.blue = (png_uint_16)data.blue; + } + + else + back.gray = (png_uint_16)data.red; + +# ifdef PNG_FLOATING_POINT_SUPPORTED + png_set_background(pp, &back, PNG_BACKGROUND_GAMMA_FILE, 1/*need expand*/, + 0); +# else + png_set_background_fixed(pp, &back, PNG_BACKGROUND_GAMMA_FILE, + 1/*need expand*/, 0); +# endif + + this->next->set(this->next, that, pp, pi); +} + +static void +image_transform_png_set_background_mod(PNG_CONST image_transform *this, + image_pixel *that, png_structp pp, PNG_CONST transform_display *display) +{ + /* Check for tRNS first: */ + if (that->have_tRNS && that->colour_type != PNG_COLOR_TYPE_PALETTE) + image_pixel_add_alpha(that, &display->this); + + /* This is only necessary if the alpha value is less than 1. */ + if (that->alphaf < 1) + { + /* Now we do the background calculation without any gamma correction. */ + if (that->alphaf <= 0) + { + that->redf = data.redf; + that->greenf = data.greenf; + that->bluef = data.bluef; + + that->rede = data.rede; + that->greene = data.greene; + that->bluee = data.bluee; + + that->red_sBIT= data.red_sBIT; + that->green_sBIT= data.green_sBIT; + that->blue_sBIT= data.blue_sBIT; + } + + else /* 0 < alpha < 1 */ + { + double alf = 1 - that->alphaf; + + that->redf = that->redf * that->alphaf + data.redf * alf; + that->rede = that->rede * that->alphaf + data.rede * alf + + DBL_EPSILON; + that->greenf = that->greenf * that->alphaf + data.greenf * alf; + that->greene = that->greene * that->alphaf + data.greene * alf + + DBL_EPSILON; + that->bluef = that->bluef * that->alphaf + data.bluef * alf; + that->bluee = that->bluee * that->alphaf + data.bluee * alf + + DBL_EPSILON; + } + + /* Remove the alpha type and set the alpha (not in that order.) */ + that->alphaf = 1; + that->alphae = 0; + + if (that->colour_type == PNG_COLOR_TYPE_RGB_ALPHA) + that->colour_type = PNG_COLOR_TYPE_RGB; + else if (that->colour_type == PNG_COLOR_TYPE_GRAY_ALPHA) + that->colour_type = PNG_COLOR_TYPE_GRAY; + /* PNG_COLOR_TYPE_PALETTE is not changed */ + } + + this->next->mod(this->next, that, pp, display); +} + +#define image_transform_png_set_background_add image_transform_default_add + +#undef data +IT(background); +#undef PT +#define PT ITSTRUCT(background) +#endif /* PNG_READ_BACKGROUND_SUPPORTED */ + +/* This may just be 'end' if all the transforms are disabled! */ +static image_transform *PNG_CONST image_transform_first = &PT; + +static void +transform_enable(PNG_CONST char *name) +{ + /* Everything starts out enabled, so if we see an 'enable' disabled + * everything else the first time round. + */ + static int all_disabled = 0; + int found_it = 0; + image_transform *list = image_transform_first; + + while (list != &image_transform_end) + { + if (strcmp(list->name, name) == 0) + { + list->enable = 1; + found_it = 1; + } + else if (!all_disabled) + list->enable = 0; + + list = list->list; + } + + all_disabled = 1; + + if (!found_it) + { + fprintf(stderr, "pngvalid: --transform-enable=%s: unknown transform\n", + name); + exit(1); + } +} + +static void +transform_disable(PNG_CONST char *name) +{ + image_transform *list = image_transform_first; + + while (list != &image_transform_end) + { + if (strcmp(list->name, name) == 0) + { + list->enable = 0; + return; + } + + list = list->list; + } + + fprintf(stderr, "pngvalid: --transform-disable=%s: unknown transform\n", + name); + exit(1); +} + +static void +image_transform_reset_count(void) +{ + image_transform *next = image_transform_first; + int count = 0; + + while (next != &image_transform_end) + { + next->local_use = 0; + next->next = 0; + next = next->list; + ++count; + } + + /* This can only happen if we every have more than 32 transforms (excluding + * the end) in the list. + */ + if (count > 32) abort(); +} + +static int +image_transform_test_counter(png_uint_32 counter, unsigned int max) +{ + /* Test the list to see if there is any point contining, given a current + * counter and a 'max' value. + */ + image_transform *next = image_transform_first; + + while (next != &image_transform_end) + { + /* For max 0 or 1 continue until the counter overflows: */ + counter >>= 1; + + /* Continue if any entry hasn't reacked the max. */ + if (max > 1 && next->local_use < max) + return 1; + next = next->list; + } + + return max <= 1 && counter == 0; +} + +static png_uint_32 +image_transform_add(PNG_CONST image_transform **this, unsigned int max, + png_uint_32 counter, char *name, size_t sizeof_name, size_t *pos, + png_byte colour_type, png_byte bit_depth) +{ + for (;;) /* until we manage to add something */ + { + png_uint_32 mask; + image_transform *list; + + /* Find the next counter value, if the counter is zero this is the start + * of the list. This routine always returns the current counter (not the + * next) so it returns 0 at the end and expects 0 at the beginning. + */ + if (counter == 0) /* first time */ + { + image_transform_reset_count(); + if (max <= 1) + counter = 1; + else + counter = random_32(); + } + else /* advance the counter */ + { + switch (max) + { + case 0: ++counter; break; + case 1: counter <<= 1; break; + default: counter = random_32(); break; + } + } + + /* Now add all these items, if possible */ + *this = &image_transform_end; + list = image_transform_first; + mask = 1; + + /* Go through the whole list adding anything that the counter selects: */ + while (list != &image_transform_end) + { + if ((counter & mask) != 0 && list->enable && + (max == 0 || list->local_use < max)) + { + /* Candidate to add: */ + if (list->add(list, this, colour_type, bit_depth) || max == 0) + { + /* Added, so add to the name too. */ + *pos = safecat(name, sizeof_name, *pos, " +"); + *pos = safecat(name, sizeof_name, *pos, list->name); + } + + else + { + /* Not useful and max>0, so remove it from *this: */ + *this = list->next; + list->next = 0; + + /* And, since we know it isn't useful, stop it being added again + * in this run: + */ + list->local_use = max; + } + } + + mask <<= 1; + list = list->list; + } + + /* Now if anything was added we have something to do. */ + if (*this != &image_transform_end) + return counter; + + /* Nothing added, but was there anything in there to add? */ + if (!image_transform_test_counter(counter, max)) + return 0; + } +} + +#ifdef THIS_IS_THE_PROFORMA +static void +image_transform_png_set_@_set(PNG_CONST image_transform *this, + transform_display *that, png_structp pp, png_infop pi) +{ + png_set_@(pp); + this->next->set(this->next, that, pp, pi); +} + +static void +image_transform_png_set_@_mod(PNG_CONST image_transform *this, + image_pixel *that, png_structp pp, PNG_CONST transform_display *display) +{ + this->next->mod(this->next, that, pp, display); +} + +static int +image_transform_png_set_@_add(image_transform *this, + PNG_CONST image_transform **that, char *name, size_t sizeof_name, + size_t *pos, png_byte colour_type, png_byte bit_depth) +{ + this->next = *that; + *that = this; + + *pos = safecat(name, sizeof_name, *pos, " +@"); + + return 1; +} + +IT(@); +#endif + +/* png_set_quantize(png_structp, png_colorp palette, int num_palette, + * int maximum_colors, png_const_uint_16p histogram, int full_quantize) + * + * Very difficult to validate this! + */ +/*NOTE: TBD NYI */ + +/* The data layout transforms are handled by swapping our own channel data, + * necessarily these need to happen at the end of the transform list because the + * semantic of the channels changes after these are executed. Some of these, + * like set_shift and set_packing, can't be done at present because they change + * the layout of the data at the sub-sample level so sample() won't get the + * right answer. + */ +/* png_set_invert_alpha */ +/*NOTE: TBD NYI */ + +/* png_set_bgr */ +/*NOTE: TBD NYI */ + +/* png_set_swap_alpha */ +/*NOTE: TBD NYI */ + +/* png_set_swap */ +/*NOTE: TBD NYI */ + +/* png_set_filler, (png_structp png_ptr, png_uint_32 filler, int flags)); */ +/*NOTE: TBD NYI */ + +/* png_set_add_alpha, (png_structp png_ptr, png_uint_32 filler, int flags)); */ +/*NOTE: TBD NYI */ + +/* png_set_packing */ +/*NOTE: TBD NYI */ + +/* png_set_packswap */ +/*NOTE: TBD NYI */ + +/* png_set_invert_mono */ +/*NOTE: TBD NYI */ + +/* png_set_shift(png_structp, png_const_color_8p true_bits) */ +/*NOTE: TBD NYI */ + +static void +perform_transform_test(png_modifier *pm) +{ + png_byte colour_type = 0; + png_byte bit_depth = 0; + int palette_number = 0; + + while (next_format(&colour_type, &bit_depth, &palette_number)) + { + png_uint_32 counter = 0; + size_t base_pos; + char name[64]; + + base_pos = safecat(name, sizeof name, 0, "transform:"); + + for (;;) + { + size_t pos = base_pos; + PNG_CONST image_transform *list = 0; + + /* 'max' is currently hardwired to '1'; this should be settable on the + * command line. + */ + counter = image_transform_add(&list, 1/*max*/, counter, + name, sizeof name, &pos, colour_type, bit_depth); + + if (counter == 0) + break; + + /* The command line can change this to checking interlaced images. */ + do + { + pm->repeat = 0; + transform_test(pm, FILEID(colour_type, bit_depth, palette_number, + pm->interlace_type, 0, 0, 0), list, name); + + if (fail(pm)) + return; + } + while (pm->repeat); + } + } +} +#endif /* PNG_READ_TRANSFORMS_SUPPORTED */ + +/********************************* GAMMA TESTS ********************************/ +#ifdef PNG_READ_GAMMA_SUPPORTED +/* Reader callbacks and implementations, where they differ from the standard + * ones. + */ +typedef struct gamma_display +{ + standard_display this; + + /* Parameters */ + png_modifier* pm; + double file_gamma; + double screen_gamma; + double background_gamma; + png_byte sbit; + int threshold_test; + int use_input_precision; + int scale16; + int expand16; + int do_background; + png_color_16 background_color; + + /* Local variables */ + double maxerrout; + double maxerrpc; + double maxerrabs; +} gamma_display; + +#define ALPHA_MODE_OFFSET 4 + +static void +gamma_display_init(gamma_display *dp, png_modifier *pm, png_uint_32 id, + double file_gamma, double screen_gamma, png_byte sbit, int threshold_test, + int use_input_precision, int scale16, int expand16, + int do_background, PNG_CONST png_color_16 *pointer_to_the_background_color, + double background_gamma) +{ + /* Standard fields */ + standard_display_init(&dp->this, &pm->this, id, 0/*do_interlace*/, + pm->use_update_info); + + /* Parameter fields */ + dp->pm = pm; + dp->file_gamma = file_gamma; + dp->screen_gamma = screen_gamma; + dp->background_gamma = background_gamma; + dp->sbit = sbit; + dp->threshold_test = threshold_test; + dp->use_input_precision = use_input_precision; + dp->scale16 = scale16; + dp->expand16 = expand16; + dp->do_background = do_background; + if (do_background && pointer_to_the_background_color != 0) + dp->background_color = *pointer_to_the_background_color; + else + memset(&dp->background_color, 0, sizeof dp->background_color); + + /* Local variable fields */ + dp->maxerrout = dp->maxerrpc = dp->maxerrabs = 0; +} + +static void +gamma_info_imp(gamma_display *dp, png_structp pp, png_infop pi) +{ + /* Reuse the standard stuff as appropriate. */ + standard_info_part1(&dp->this, pp, pi); + + /* If requested strip 16 to 8 bits - this is handled automagically below + * because the output bit depth is read from the library. Note that there + * are interactions with sBIT but, internally, libpng makes sbit at most + * PNG_MAX_GAMMA_8 when doing the following. + */ + if (dp->scale16) +# ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED + png_set_scale_16(pp); +# else + /* The following works both in 1.5.4 and earlier versions: */ +# ifdef PNG_READ_16_TO_8_SUPPORTED + png_set_strip_16(pp); +# else + png_error(pp, "scale16 (16 to 8 bit conversion) not supported"); +# endif +# endif + + if (dp->expand16) +# ifdef PNG_READ_EXPAND_16_SUPPORTED + png_set_expand_16(pp); +# else + png_error(pp, "expand16 (8 to 16 bit conversion) not supported"); +# endif + + if (dp->do_background >= ALPHA_MODE_OFFSET) + { +# ifdef PNG_READ_ALPHA_MODE_SUPPORTED + { + /* This tests the alpha mode handling, if supported. */ + int mode = dp->do_background - ALPHA_MODE_OFFSET; + + /* The gamma value is the output gamma, and is in the standard, + * non-inverted, represenation. It provides a default for the PNG file + * gamma, but since the file has a gAMA chunk this does not matter. + */ + PNG_CONST double sg = dp->screen_gamma; +# ifndef PNG_FLOATING_POINT_SUPPORTED + PNG_CONST png_fixed_point g = fix(sg); +# endif + +# ifdef PNG_FLOATING_POINT_SUPPORTED + png_set_alpha_mode(pp, mode, sg); +# else + png_set_alpha_mode_fixed(pp, mode, g); +# endif + + /* However, for the standard Porter-Duff algorithm the output defaults + * to be linear, so if the test requires non-linear output it must be + * corrected here. + */ + if (mode == PNG_ALPHA_STANDARD && sg != 1) + { +# ifdef PNG_FLOATING_POINT_SUPPORTED + png_set_gamma(pp, sg, dp->file_gamma); +# else + png_fixed_point f = fix(dp->file_gamma); + png_set_gamma_fixed(pp, g, f); +# endif + } + } +# else + png_error(pp, "alpha mode handling not supported"); +# endif + } + + else + { + /* Set up gamma processing. */ +# ifdef PNG_FLOATING_POINT_SUPPORTED + png_set_gamma(pp, dp->screen_gamma, dp->file_gamma); +# else + { + png_fixed_point s = fix(dp->screen_gamma); + png_fixed_point f = fix(dp->file_gamma); + png_set_gamma_fixed(pp, s, f); + } +# endif + + if (dp->do_background) + { +# ifdef PNG_READ_BACKGROUND_SUPPORTED + /* NOTE: this assumes the caller provided the correct background gamma! + */ + PNG_CONST double bg = dp->background_gamma; +# ifndef PNG_FLOATING_POINT_SUPPORTED + PNG_CONST png_fixed_point g = fix(bg); +# endif + +# ifdef PNG_FLOATING_POINT_SUPPORTED + png_set_background(pp, &dp->background_color, dp->do_background, + 0/*need_expand*/, bg); +# else + png_set_background_fixed(pp, &dp->background_color, + dp->do_background, 0/*need_expand*/, g); +# endif +# else + png_error(pp, "png_set_background not supported"); +# endif + } + } + + { + int i = dp->this.use_update_info; + /* Always do one call, even if use_update_info is 0. */ + do + png_read_update_info(pp, pi); + while (--i > 0); + } + + /* Now we may get a different cbRow: */ + standard_info_part2(&dp->this, pp, pi, 1 /*images*/); +} + +static void +gamma_info(png_structp pp, png_infop pi) +{ + gamma_info_imp(voidcast(gamma_display*, png_get_progressive_ptr(pp)), pp, + pi); +} + +/* Validate a single component value - the routine gets the input and output + * sample values as unscaled PNG component values along with a cache of all the + * information required to validate the values. + */ +typedef struct validate_info +{ + png_structp pp; + gamma_display *dp; + png_byte sbit; + int use_input_precision; + int do_background; + int scale16; + unsigned int sbit_max; + unsigned int isbit_shift; + unsigned int outmax; + + double gamma_correction; /* Overall correction required. */ + double file_inverse; /* Inverse of file gamma. */ + double screen_gamma; + double screen_inverse; /* Inverse of screen gamma. */ + + double background_red; /* Linear background value, red or gray. */ + double background_green; + double background_blue; + + double maxabs; + double maxpc; + double maxcalc; + double maxout; + double maxout_total; /* Total including quantization error */ + double outlog; + int outquant; +} +validate_info; + +static void +init_validate_info(validate_info *vi, gamma_display *dp, png_struct *pp, + int in_depth, int out_depth) +{ + PNG_CONST unsigned int outmax = (1U<pp = pp; + vi->dp = dp; + + if (dp->sbit > 0 && dp->sbit < in_depth) + { + vi->sbit = dp->sbit; + vi->isbit_shift = in_depth - dp->sbit; + } + + else + { + vi->sbit = (png_byte)in_depth; + vi->isbit_shift = 0; + } + + vi->sbit_max = (1U << vi->sbit)-1; + + /* This mimics the libpng threshold test, '0' is used to prevent gamma + * correction in the validation test. + */ + vi->screen_gamma = dp->screen_gamma; + if (fabs(vi->screen_gamma-1) < PNG_GAMMA_THRESHOLD) + vi->screen_gamma = vi->screen_inverse = 0; + else + vi->screen_inverse = 1/vi->screen_gamma; + + vi->use_input_precision = dp->use_input_precision; + vi->outmax = outmax; + vi->maxabs = abserr(dp->pm, in_depth, out_depth); + vi->maxpc = pcerr(dp->pm, in_depth, out_depth); + vi->maxcalc = calcerr(dp->pm, in_depth, out_depth); + vi->maxout = outerr(dp->pm, in_depth, out_depth); + vi->outquant = output_quantization_factor(dp->pm, in_depth, out_depth); + vi->maxout_total = vi->maxout + vi->outquant * .5; + vi->outlog = outlog(dp->pm, in_depth, out_depth); + + if ((dp->this.colour_type & PNG_COLOR_MASK_ALPHA) != 0 || + (dp->this.colour_type == 3 && dp->this.is_transparent)) + { + vi->do_background = dp->do_background; + + if (vi->do_background != 0) + { + PNG_CONST double bg_inverse = 1/dp->background_gamma; + double r, g, b; + + /* Caller must at least put the gray value into the red channel */ + r = dp->background_color.red; r /= outmax; + g = dp->background_color.green; g /= outmax; + b = dp->background_color.blue; b /= outmax; + +# if 0 + /* libpng doesn't do this optimization, if we do pngvalid will fail. + */ + if (fabs(bg_inverse-1) >= PNG_GAMMA_THRESHOLD) +# endif + { + r = pow(r, bg_inverse); + g = pow(g, bg_inverse); + b = pow(b, bg_inverse); + } + + vi->background_red = r; + vi->background_green = g; + vi->background_blue = b; + } + } + else + vi->do_background = 0; + + if (vi->do_background == 0) + vi->background_red = vi->background_green = vi->background_blue = 0; + + vi->gamma_correction = 1/(dp->file_gamma*dp->screen_gamma); + if (fabs(vi->gamma_correction-1) < PNG_GAMMA_THRESHOLD) + vi->gamma_correction = 0; + + vi->file_inverse = 1/dp->file_gamma; + if (fabs(vi->file_inverse-1) < PNG_GAMMA_THRESHOLD) + vi->file_inverse = 0; + + vi->scale16 = dp->scale16; +} + +/* This function handles composition of a single non-alpha component. The + * argument is the input sample value, in the range 0..1, and the alpha value. + * The result is the composed, linear, input sample. If alpha is less than zero + * this is the alpha component and the function should not be called! + */ +static double +gamma_component_compose(int do_background, double input_sample, double alpha, + double background, int *compose) +{ + switch (do_background) + { + case PNG_BACKGROUND_GAMMA_SCREEN: + case PNG_BACKGROUND_GAMMA_FILE: + case PNG_BACKGROUND_GAMMA_UNIQUE: + /* Standard PNG background processing. */ + if (alpha < 1) + { + if (alpha > 0) + { + input_sample = input_sample * alpha + background * (1-alpha); + if (compose != NULL) + *compose = 1; + } + + else + input_sample = background; + } + break; + +#ifdef PNG_READ_ALPHA_MODE_SUPPORTED + case ALPHA_MODE_OFFSET + PNG_ALPHA_STANDARD: + case ALPHA_MODE_OFFSET + PNG_ALPHA_BROKEN: + /* The components are premultiplied in either case and the output is + * gamma encoded (to get standard Porter-Duff we expect the output + * gamma to be set to 1.0!) + */ + case ALPHA_MODE_OFFSET + PNG_ALPHA_OPTIMIZED: + /* The optimization is that the partial-alpha entries are linear + * while the opaque pixels are gamma encoded, but this only affects the + * output encoding. + */ + if (alpha < 1) + { + if (alpha > 0) + { + input_sample *= alpha; + if (compose != NULL) + *compose = 1; + } + + else + input_sample = 0; + } + break; +#endif + + default: + /* Standard cases where no compositing is done (so the component + * value is already correct.) + */ + break; + } + + return input_sample; +} + +/* This API returns the encoded *input* component, in the range 0..1 */ +static double +gamma_component_validate(PNG_CONST char *name, PNG_CONST validate_info *vi, + PNG_CONST unsigned int id, PNG_CONST unsigned int od, + PNG_CONST double alpha /* <0 for the alpha channel itself */, + PNG_CONST double background /* component background value */) +{ + PNG_CONST unsigned int isbit = id >> vi->isbit_shift; + PNG_CONST unsigned int sbit_max = vi->sbit_max; + PNG_CONST unsigned int outmax = vi->outmax; + PNG_CONST int do_background = vi->do_background; + + double i; + + /* First check on the 'perfect' result obtained from the digitized input + * value, id, and compare this against the actual digitized result, 'od'. + * 'i' is the input result in the range 0..1: + */ + i = isbit; i /= sbit_max; + + /* Check for the fast route: if we don't do any background composition or if + * this is the alpha channel ('alpha' < 0) or if the pixel is opaque then + * just use the gamma_correction field to correct to the final output gamma. + */ + if (alpha == 1 /* opaque pixel component */ || !do_background +#ifdef PNG_READ_ALPHA_MODE_SUPPORTED + || do_background == ALPHA_MODE_OFFSET + PNG_ALPHA_PNG +#endif + || (alpha < 0 /* alpha channel */ +#ifdef PNG_READ_ALPHA_MODE_SUPPORTED + && do_background != ALPHA_MODE_OFFSET + PNG_ALPHA_BROKEN +#endif + )) + { + /* Then get the gamma corrected version of 'i' and compare to 'od', any + * error less than .5 is insignificant - just quantization of the output + * value to the nearest digital value (nevertheless the error is still + * recorded - it's interesting ;-) + */ + double encoded_sample = i; + double encoded_error; + + /* alpha less than 0 indicates the alpha channel, which is always linear + */ + if (alpha >= 0 && vi->gamma_correction > 0) + encoded_sample = pow(encoded_sample, vi->gamma_correction); + encoded_sample *= outmax; + + encoded_error = fabs(od-encoded_sample); + + if (encoded_error > vi->dp->maxerrout) + vi->dp->maxerrout = encoded_error; + + if (encoded_error < vi->maxout_total && encoded_error < vi->outlog) + return i; + } + + /* The slow route - attempt to do linear calculations. */ + /* There may be an error, or background processing is required, so calculate + * the actual sample values - unencoded light intensity values. Note that in + * practice these are not completely unencoded because they include a + * 'viewing correction' to decrease or (normally) increase the perceptual + * contrast of the image. There's nothing we can do about this - we don't + * know what it is - so assume the unencoded value is perceptually linear. + */ + { + double input_sample = i; /* In range 0..1 */ + double output, error, encoded_sample, encoded_error; + double es_lo, es_hi; + int compose = 0; /* Set to one if composition done */ + int output_is_encoded; /* Set if encoded to screen gamma */ + int log_max_error = 1; /* Check maximum error values */ + png_const_charp pass = 0; /* Reason test passes (or 0 for fail) */ + + /* Convert to linear light (with the above caveat.) The alpha channel is + * already linear. + */ + if (alpha >= 0) + { + int tcompose; + + if (vi->file_inverse > 0) + input_sample = pow(input_sample, vi->file_inverse); + + /* Handle the compose processing: */ + tcompose = 0; + input_sample = gamma_component_compose(do_background, input_sample, + alpha, background, &tcompose); + + if (tcompose) + compose = 1; + } + + /* And similarly for the output value, but we need to check the background + * handling to linearize it correctly. + */ + output = od; + output /= outmax; + + output_is_encoded = vi->screen_gamma > 0; + + if (alpha < 0) /* The alpha channel */ + { +#ifdef PNG_READ_ALPHA_MODE_SUPPORTED + if (do_background != ALPHA_MODE_OFFSET + PNG_ALPHA_BROKEN) +#endif + { + /* In all other cases the output alpha channel is linear already, + * don't log errors here, they are much larger in linear data. + */ + output_is_encoded = 0; + log_max_error = 0; + } + } + +#ifdef PNG_READ_ALPHA_MODE_SUPPORTED + else /* A component */ + { + if (do_background == ALPHA_MODE_OFFSET + PNG_ALPHA_OPTIMIZED && + alpha < 1) /* the optimized case - linear output */ + { + if (alpha > 0) log_max_error = 0; + output_is_encoded = 0; + } + } +#endif + + if (output_is_encoded) + output = pow(output, vi->screen_gamma); + + /* Calculate (or recalculate) the encoded_sample value and repeat the + * check above (unnecessary if we took the fast route, but harmless.) + */ + encoded_sample = input_sample; + if (output_is_encoded) + encoded_sample = pow(encoded_sample, vi->screen_inverse); + encoded_sample *= outmax; + + encoded_error = fabs(od-encoded_sample); + + /* Don't log errors in the alpha channel, or the 'optimized' case, + * neither are significant to the overall perception. + */ + if (log_max_error && encoded_error > vi->dp->maxerrout) + vi->dp->maxerrout = encoded_error; + + if (encoded_error < vi->maxout_total) + { + if (encoded_error < vi->outlog) + return i; + + /* Test passed but error is bigger than the log limit, record why the + * test passed: + */ + pass = "less than maxout:\n"; + } + + /* i: the original input value in the range 0..1 + * + * pngvalid calculations: + * input_sample: linear result; i linearized and composed, range 0..1 + * encoded_sample: encoded result; input_sample scaled to ouput bit depth + * + * libpng calculations: + * output: linear result; od scaled to 0..1 and linearized + * od: encoded result from libpng + */ + + /* Now we have the numbers for real errors, both absolute values as as a + * percentage of the correct value (output): + */ + error = fabs(input_sample-output); + + if (log_max_error && error > vi->dp->maxerrabs) + vi->dp->maxerrabs = error; + + /* The following is an attempt to ignore the tendency of quantization to + * dominate the percentage errors for lower result values: + */ + if (log_max_error && input_sample > .5) + { + double percentage_error = error/input_sample; + if (percentage_error > vi->dp->maxerrpc) + vi->dp->maxerrpc = percentage_error; + } + + /* Now calculate the digitization limits for 'encoded_sample' using the + * 'max' values. Note that maxout is in the encoded space but maxpc and + * maxabs are in linear light space. + * + * First find the maximum error in linear light space, range 0..1: + */ + { + double tmp = input_sample * vi->maxpc; + if (tmp < vi->maxabs) tmp = vi->maxabs; + /* If 'compose' is true the composition was done in linear space using + * integer arithmetic. This introduces an extra error of +/- 0.5 (at + * least) in the integer space used. 'maxcalc' records this, taking + * into account the possibility that even for 16 bit output 8 bit space + * may have been used. + */ + if (compose && tmp < vi->maxcalc) tmp = vi->maxcalc; + + /* The 'maxout' value refers to the encoded result, to compare with + * this encode input_sample adjusted by the maximum error (tmp) above. + */ + es_lo = encoded_sample - vi->maxout; + + if (es_lo > 0 && input_sample-tmp > 0) + { + double low_value = input_sample-tmp; + if (output_is_encoded) + low_value = pow(low_value, vi->screen_inverse); + low_value *= outmax; + if (low_value < es_lo) es_lo = low_value; + + /* Quantize this appropriately: */ + es_lo = ceil(es_lo / vi->outquant - .5) * vi->outquant; + } + + else + es_lo = 0; + + es_hi = encoded_sample + vi->maxout; + + if (es_hi < outmax && input_sample+tmp < 1) + { + double high_value = input_sample+tmp; + if (output_is_encoded) + high_value = pow(high_value, vi->screen_inverse); + high_value *= outmax; + if (high_value > es_hi) es_hi = high_value; + + es_hi = floor(es_hi / vi->outquant + .5) * vi->outquant; + } + + else + es_hi = outmax; + } + + /* The primary test is that the final encoded value returned by the + * library should be between the two limits (inclusive) that were + * calculated above. + */ + if (od >= es_lo && od <= es_hi) + { + /* The value passes, but we may need to log the information anyway. */ + if (encoded_error < vi->outlog) + return i; + + if (pass == 0) + pass = "within digitization limits:\n"; + } + + { + /* There has been an error in processing, or we need to log this + * value. + */ + double is_lo, is_hi; + + /* pass is set at this point if either of the tests above would have + * passed. Don't do these additional tests here - just log the + * original [es_lo..es_hi] values. + */ + if (pass == 0 && vi->use_input_precision) + { + /* Ok, something is wrong - this actually happens in current libpng + * 16-to-8 processing. Assume that the input value (id, adjusted + * for sbit) can be anywhere between value-.5 and value+.5 - quite a + * large range if sbit is low. + */ + double tmp = (isbit - .5)/sbit_max; + + if (tmp <= 0) + tmp = 0; + + else if (alpha >= 0 && vi->file_inverse > 0 && tmp < 1) + tmp = pow(tmp, vi->file_inverse); + + tmp = gamma_component_compose(do_background, tmp, alpha, background, + NULL); + + if (output_is_encoded && tmp > 0 && tmp < 1) + tmp = pow(tmp, vi->screen_inverse); + + is_lo = ceil(outmax * tmp - vi->maxout_total); + + if (is_lo < 0) + is_lo = 0; + + tmp = (isbit + .5)/sbit_max; + + if (tmp <= 0) + tmp = 0; + + else if (alpha >= 0 && vi->file_inverse > 0 && tmp < 1) + tmp = pow(tmp, vi->file_inverse); + + tmp = gamma_component_compose(do_background, tmp, alpha, background, + NULL); + + if (output_is_encoded && tmp > 0 && tmp < 1) + tmp = pow(tmp, vi->screen_inverse); + + is_hi = floor(outmax * tmp + vi->maxout_total); + + if (is_hi > outmax) + is_hi = outmax; + + if (!(od < is_lo || od > is_hi)) + { + if (encoded_error < vi->outlog) + return i; + + pass = "within input precision limits:\n"; + } + + /* One last chance. If this is an alpha channel and the 16to8 + * option has been used and 'inaccurate' scaling is used then the + * bit reduction is obtained by simply using the top 8 bits of the + * value. + * + * This is only done for older libpng versions when the 'inaccurate' + * (chop) method of scaling was used. + */ +# ifndef PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED +# if PNG_LIBPNG_VER < 10504 + /* This may be required for other components in the future, + * but at present the presence of gamma correction effectively + * prevents the errors in the component scaling (I don't quite + * understand why, but since it's better this way I care not + * to ask, JB 20110419.) + */ + if (pass == 0 && alpha < 0 && vi->scale16 && vi->sbit > 8 && + vi->sbit + vi->isbit_shift == 16) + { + tmp = ((id >> 8) - .5)/255; + + if (tmp > 0) + { + is_lo = ceil(outmax * tmp - vi->maxout_total); + if (is_lo < 0) is_lo = 0; + } + + else + is_lo = 0; + + tmp = ((id >> 8) + .5)/255; + + if (tmp < 1) + { + is_hi = floor(outmax * tmp + vi->maxout_total); + if (is_hi > outmax) is_hi = outmax; + } + + else + is_hi = outmax; + + if (!(od < is_lo || od > is_hi)) + { + if (encoded_error < vi->outlog) + return i; + + pass = "within 8 bit limits:\n"; + } + } +# endif +# endif + } + else /* !use_input_precision */ + is_lo = es_lo, is_hi = es_hi; + + /* Attempt to output a meaningful error/warning message: the message + * output depends on the background/composite operation being performed + * because this changes what parameters were actually used above. + */ + { + size_t pos = 0; + /* Need either 1/255 or 1/65535 precision here; 3 or 6 decimal + * places. Just use outmax to work out which. + */ + int precision = (outmax >= 1000 ? 6 : 3); + int use_input=1, use_background=0, do_compose=0; + char msg[256]; + + if (pass != 0) + pos = safecat(msg, sizeof msg, pos, "\n\t"); + + /* Set up the various flags, the output_is_encoded flag above + * is also used below. do_compose is just a double check. + */ + switch (do_background) + { + case PNG_BACKGROUND_GAMMA_SCREEN: + case PNG_BACKGROUND_GAMMA_FILE: + case PNG_BACKGROUND_GAMMA_UNIQUE: + use_background = (alpha >= 0 && alpha < 1); + /*FALL THROUGH*/ +# ifdef PNG_READ_ALPHA_MODE_SUPPORTED + case ALPHA_MODE_OFFSET + PNG_ALPHA_STANDARD: + case ALPHA_MODE_OFFSET + PNG_ALPHA_BROKEN: + case ALPHA_MODE_OFFSET + PNG_ALPHA_OPTIMIZED: +# endif /* ALPHA_MODE_SUPPORTED */ + do_compose = (alpha > 0 && alpha < 1); + use_input = (alpha != 0); + break; + + default: + break; + } + + /* Check the 'compose' flag */ + if (compose != do_compose) + png_error(vi->pp, "internal error (compose)"); + + /* 'name' is the component name */ + pos = safecat(msg, sizeof msg, pos, name); + pos = safecat(msg, sizeof msg, pos, "("); + pos = safecatn(msg, sizeof msg, pos, id); + if (use_input || pass != 0/*logging*/) + { + if (isbit != id) + { + /* sBIT has reduced the precision of the input: */ + pos = safecat(msg, sizeof msg, pos, ", sbit("); + pos = safecatn(msg, sizeof msg, pos, vi->sbit); + pos = safecat(msg, sizeof msg, pos, "): "); + pos = safecatn(msg, sizeof msg, pos, isbit); + } + pos = safecat(msg, sizeof msg, pos, "/"); + /* The output is either "id/max" or "id sbit(sbit): isbit/max" */ + pos = safecatn(msg, sizeof msg, pos, vi->sbit_max); + } + pos = safecat(msg, sizeof msg, pos, ")"); + + /* A component may have been multiplied (in linear space) by the + * alpha value, 'compose' says whether this is relevant. + */ + if (compose || pass != 0) + { + /* If any form of composition is being done report our + * calculated linear value here (the code above doesn't record + * the input value before composition is performed, so what + * gets reported is the value after composition.) + */ + if (use_input || pass != 0) + { + if (vi->file_inverse > 0) + { + pos = safecat(msg, sizeof msg, pos, "^"); + pos = safecatd(msg, sizeof msg, pos, vi->file_inverse, 2); + } + + else + pos = safecat(msg, sizeof msg, pos, "[linear]"); + + pos = safecat(msg, sizeof msg, pos, "*(alpha)"); + pos = safecatd(msg, sizeof msg, pos, alpha, precision); + } + + /* Now record the *linear* background value if it was used + * (this function is not passed the original, non-linear, + * value but it is contained in the test name.) + */ + if (use_background) + { + pos = safecat(msg, sizeof msg, pos, use_input ? "+" : " "); + pos = safecat(msg, sizeof msg, pos, "(background)"); + pos = safecatd(msg, sizeof msg, pos, background, precision); + pos = safecat(msg, sizeof msg, pos, "*"); + pos = safecatd(msg, sizeof msg, pos, 1-alpha, precision); + } + } + + /* Report the calculated value (input_sample) and the linearized + * libpng value (output) unless this is just a component gamma + * correction. + */ + if (compose || alpha < 0 || pass != 0) + { + pos = safecat(msg, sizeof msg, pos, + pass != 0 ? " =\n\t" : " = "); + pos = safecatd(msg, sizeof msg, pos, input_sample, precision); + pos = safecat(msg, sizeof msg, pos, " (libpng: "); + pos = safecatd(msg, sizeof msg, pos, output, precision); + pos = safecat(msg, sizeof msg, pos, ")"); + + /* Finally report the output gamma encoding, if any. */ + if (output_is_encoded) + { + pos = safecat(msg, sizeof msg, pos, " ^"); + pos = safecatd(msg, sizeof msg, pos, vi->screen_inverse, 2); + pos = safecat(msg, sizeof msg, pos, "(to screen) ="); + } + + else + pos = safecat(msg, sizeof msg, pos, " [screen is linear] ="); + } + + if ((!compose && alpha >= 0) || pass != 0) + { + if (pass != 0) /* logging */ + pos = safecat(msg, sizeof msg, pos, "\n\t[overall:"); + + /* This is the non-composition case, the internal linear + * values are irrelevant (though the log below will reveal + * them.) Output a much shorter warning/error message and report + * the overall gamma correction. + */ + if (vi->gamma_correction > 0) + { + pos = safecat(msg, sizeof msg, pos, " ^"); + pos = safecatd(msg, sizeof msg, pos, vi->gamma_correction, 2); + pos = safecat(msg, sizeof msg, pos, "(gamma correction) ="); + } + + else + pos = safecat(msg, sizeof msg, pos, + " [no gamma correction] ="); + + if (pass != 0) + pos = safecat(msg, sizeof msg, pos, "]"); + } + + /* This is our calculated encoded_sample which should (but does + * not) match od: + */ + pos = safecat(msg, sizeof msg, pos, pass != 0 ? "\n\t" : " "); + pos = safecatd(msg, sizeof msg, pos, is_lo, 1); + pos = safecat(msg, sizeof msg, pos, " < "); + pos = safecatd(msg, sizeof msg, pos, encoded_sample, 1); + pos = safecat(msg, sizeof msg, pos, " (libpng: "); + pos = safecatn(msg, sizeof msg, pos, od); + pos = safecat(msg, sizeof msg, pos, ")"); + pos = safecat(msg, sizeof msg, pos, "/"); + pos = safecatn(msg, sizeof msg, pos, outmax); + pos = safecat(msg, sizeof msg, pos, " < "); + pos = safecatd(msg, sizeof msg, pos, is_hi, 1); + + if (pass == 0) /* The error condition */ + { +# ifdef PNG_WARNINGS_SUPPORTED + png_warning(vi->pp, msg); +# else + store_warning(vi->pp, msg); +# endif + } + + else /* logging this value */ + store_verbose(&vi->dp->pm->this, vi->pp, pass, msg); + } + } + } + + return i; +} + +static void +gamma_image_validate(gamma_display *dp, png_structp pp, png_infop pi) +{ + /* Get some constants derived from the input and output file formats: */ + PNG_CONST png_store* PNG_CONST ps = dp->this.ps; + PNG_CONST png_byte in_ct = dp->this.colour_type; + PNG_CONST png_byte in_bd = dp->this.bit_depth; + PNG_CONST png_uint_32 w = dp->this.w; + PNG_CONST png_uint_32 h = dp->this.h; + PNG_CONST size_t cbRow = dp->this.cbRow; + PNG_CONST png_byte out_ct = png_get_color_type(pp, pi); + PNG_CONST png_byte out_bd = png_get_bit_depth(pp, pi); + + /* There are three sources of error, firstly the quantization in the + * file encoding, determined by sbit and/or the file depth, secondly + * the output (screen) gamma and thirdly the output file encoding. + * + * Since this API receives the screen and file gamma in double + * precision it is possible to calculate an exact answer given an input + * pixel value. Therefore we assume that the *input* value is exact - + * sample/maxsample - calculate the corresponding gamma corrected + * output to the limits of double precision arithmetic and compare with + * what libpng returns. + * + * Since the library must quantize the output to 8 or 16 bits there is + * a fundamental limit on the accuracy of the output of +/-.5 - this + * quantization limit is included in addition to the other limits + * specified by the paramaters to the API. (Effectively, add .5 + * everywhere.) + * + * The behavior of the 'sbit' paramter is defined by section 12.5 + * (sample depth scaling) of the PNG spec. That section forces the + * decoder to assume that the PNG values have been scaled if sBIT is + * present: + * + * png-sample = floor( input-sample * (max-out/max-in) + .5); + * + * This means that only a subset of the possible PNG values should + * appear in the input. However, the spec allows the encoder to use a + * variety of approximations to the above and doesn't require any + * restriction of the values produced. + * + * Nevertheless the spec requires that the upper 'sBIT' bits of the + * value stored in a PNG file be the original sample bits. + * Consequently the code below simply scales the top sbit bits by + * (1<this.palette; + PNG_CONST int in_is_transparent = dp->this.is_transparent; + int out_npalette = -1; + int out_is_transparent = 0; /* Just refers to the palette case */ + store_palette out_palette; + validate_info vi; + + /* Check for row overwrite errors */ + store_image_check(dp->this.ps, pp, 0); + + /* Supply the input and output sample depths here - 8 for an indexed image, + * otherwise the bit depth. + */ + init_validate_info(&vi, dp, pp, in_ct==3?8:in_bd, out_ct==3?8:out_bd); + + processing = (vi.gamma_correction > 0 && !dp->threshold_test) + || in_bd != out_bd || in_ct != out_ct || vi.do_background; + + /* TODO: FIX THIS: MAJOR BUG! If the transformations all happen inside + * the palette there is no way of finding out, because libpng fails to + * update the palette on png_read_update_info. Indeed, libpng doesn't + * even do the required work until much later, when it doesn't have any + * info pointer. Oops. For the moment 'processing' is turned off if + * out_ct is palette. + */ + if (in_ct == 3 && out_ct == 3) + processing = 0; + + if (processing && out_ct == 3) + out_is_transparent = read_palette(out_palette, &out_npalette, pp, pi); + + for (y=0; ythis.palette[in_index].alpha : + sample(std, in_ct, in_bd, x, samples_per_pixel); + + unsigned int output_alpha = 65536 /* as a flag value */; + + if (out_ct == 3) + { + if (out_is_transparent) + output_alpha = out_palette[out_index].alpha; + } + + else if ((out_ct & PNG_COLOR_MASK_ALPHA) != 0) + output_alpha = sample(pRow, out_ct, out_bd, x, + samples_per_pixel); + + if (output_alpha != 65536) + alpha = gamma_component_validate("alpha", &vi, input_alpha, + output_alpha, -1/*alpha*/, 0/*background*/); + + else /* no alpha in output */ + { + /* This is a copy of the calculation of 'i' above in order to + * have the alpha value to use in the background calculation. + */ + alpha = input_alpha >> vi.isbit_shift; + alpha /= vi.sbit_max; + } + } + + /* Handle grayscale or RGB components. */ + if ((in_ct & PNG_COLOR_MASK_COLOR) == 0) /* grayscale */ + (void)gamma_component_validate("gray", &vi, + sample(std, in_ct, in_bd, x, 0), + sample(pRow, out_ct, out_bd, x, 0), alpha/*component*/, + vi.background_red); + else /* RGB or palette */ + { + (void)gamma_component_validate("red", &vi, + in_ct == 3 ? in_palette[in_index].red : + sample(std, in_ct, in_bd, x, 0), + out_ct == 3 ? out_palette[out_index].red : + sample(pRow, out_ct, out_bd, x, 0), + alpha/*component*/, vi.background_red); + + (void)gamma_component_validate("green", &vi, + in_ct == 3 ? in_palette[in_index].green : + sample(std, in_ct, in_bd, x, 1), + out_ct == 3 ? out_palette[out_index].green : + sample(pRow, out_ct, out_bd, x, 1), + alpha/*component*/, vi.background_green); + + (void)gamma_component_validate("blue", &vi, + in_ct == 3 ? in_palette[in_index].blue : + sample(std, in_ct, in_bd, x, 2), + out_ct == 3 ? out_palette[out_index].blue : + sample(pRow, out_ct, out_bd, x, 2), + alpha/*component*/, vi.background_blue); + } + } + } + + else if (memcmp(std, pRow, cbRow) != 0) + { + char msg[64]; + + /* No transform is expected on the threshold tests. */ + sprintf(msg, "gamma: below threshold row %d changed", y); + + png_error(pp, msg); + } + } /* row (y) loop */ + + dp->this.ps->validated = 1; +} + +static void +gamma_end(png_structp pp, png_infop pi) +{ + gamma_display *dp = voidcast(gamma_display*, png_get_progressive_ptr(pp)); + + if (!dp->this.speed) + gamma_image_validate(dp, pp, pi); + else + dp->this.ps->validated = 1; +} + +/* A single test run checking a gamma transformation. + * + * maxabs: maximum absolute error as a fraction + * maxout: maximum output error in the output units + * maxpc: maximum percentage error (as a percentage) + */ +static void +gamma_test(png_modifier *pmIn, PNG_CONST png_byte colour_typeIn, + PNG_CONST png_byte bit_depthIn, PNG_CONST int palette_numberIn, + PNG_CONST int interlace_typeIn, + PNG_CONST double file_gammaIn, PNG_CONST double screen_gammaIn, + PNG_CONST png_byte sbitIn, PNG_CONST int threshold_testIn, + PNG_CONST char *name, + PNG_CONST int use_input_precisionIn, PNG_CONST int scale16In, + PNG_CONST int expand16In, PNG_CONST int do_backgroundIn, + PNG_CONST png_color_16 *bkgd_colorIn, double bkgd_gammaIn) +{ + gamma_display d; + context(&pmIn->this, fault); + + gamma_display_init(&d, pmIn, FILEID(colour_typeIn, bit_depthIn, + palette_numberIn, interlace_typeIn, 0, 0, 0), + file_gammaIn, screen_gammaIn, sbitIn, + threshold_testIn, use_input_precisionIn, scale16In, + expand16In, do_backgroundIn, bkgd_colorIn, bkgd_gammaIn); + + Try + { + png_structp pp; + png_infop pi; + gama_modification gama_mod; + srgb_modification srgb_mod; + sbit_modification sbit_mod; + + /* For the moment don't use the png_modifier support here. */ + d.pm->encoding_counter = 0; + modifier_set_encoding(d.pm); /* Just resets everything */ + d.pm->current_gamma = d.file_gamma; + + /* Make an appropriate modifier to set the PNG file gamma to the + * given gamma value and the sBIT chunk to the given precision. + */ + d.pm->modifications = NULL; + gama_modification_init(&gama_mod, d.pm, d.file_gamma); + srgb_modification_init(&srgb_mod, d.pm, 127 /*delete*/); + if (d.sbit > 0) + sbit_modification_init(&sbit_mod, d.pm, d.sbit); + + modification_reset(d.pm->modifications); + + /* Get a png_struct for writing the image. */ + pp = set_modifier_for_read(d.pm, &pi, d.this.id, name); + standard_palette_init(&d.this); + + /* Introduce the correct read function. */ + if (d.pm->this.progressive) + { + /* Share the row function with the standard implementation. */ + png_set_progressive_read_fn(pp, &d, gamma_info, progressive_row, + gamma_end); + + /* Now feed data into the reader until we reach the end: */ + modifier_progressive_read(d.pm, pp, pi); + } + else + { + /* modifier_read expects a png_modifier* */ + png_set_read_fn(pp, d.pm, modifier_read); + + /* Check the header values: */ + png_read_info(pp, pi); + + /* Process the 'info' requirements. Only one image is generated */ + gamma_info_imp(&d, pp, pi); + + sequential_row(&d.this, pp, pi, -1, 0); + + if (!d.this.speed) + gamma_image_validate(&d, pp, pi); + else + d.this.ps->validated = 1; + } + + modifier_reset(d.pm); + + if (d.pm->log && !d.threshold_test && !d.this.speed) + fprintf(stderr, "%d bit %s %s: max error %f (%.2g, %2g%%)\n", + d.this.bit_depth, colour_types[d.this.colour_type], name, + d.maxerrout, d.maxerrabs, 100*d.maxerrpc); + + /* Log the summary values too. */ + if (d.this.colour_type == 0 || d.this.colour_type == 4) + { + switch (d.this.bit_depth) + { + case 1: + break; + + case 2: + if (d.maxerrout > d.pm->error_gray_2) + d.pm->error_gray_2 = d.maxerrout; + + break; + + case 4: + if (d.maxerrout > d.pm->error_gray_4) + d.pm->error_gray_4 = d.maxerrout; + + break; + + case 8: + if (d.maxerrout > d.pm->error_gray_8) + d.pm->error_gray_8 = d.maxerrout; + + break; + + case 16: + if (d.maxerrout > d.pm->error_gray_16) + d.pm->error_gray_16 = d.maxerrout; + + break; + + default: + png_error(pp, "bad bit depth (internal: 1)"); + } + } + + else if (d.this.colour_type == 2 || d.this.colour_type == 6) + { + switch (d.this.bit_depth) + { + case 8: + + if (d.maxerrout > d.pm->error_color_8) + d.pm->error_color_8 = d.maxerrout; + + break; + + case 16: + + if (d.maxerrout > d.pm->error_color_16) + d.pm->error_color_16 = d.maxerrout; + + break; + + default: + png_error(pp, "bad bit depth (internal: 2)"); + } + } + + else if (d.this.colour_type == 3) + { + if (d.maxerrout > d.pm->error_indexed) + d.pm->error_indexed = d.maxerrout; + } + } + + Catch(fault) + modifier_reset((png_modifier*)fault); +} + +static void gamma_threshold_test(png_modifier *pm, png_byte colour_type, + png_byte bit_depth, int interlace_type, double file_gamma, + double screen_gamma) +{ + size_t pos = 0; + char name[64]; + pos = safecat(name, sizeof name, pos, "threshold "); + pos = safecatd(name, sizeof name, pos, file_gamma, 3); + pos = safecat(name, sizeof name, pos, "/"); + pos = safecatd(name, sizeof name, pos, screen_gamma, 3); + + (void)gamma_test(pm, colour_type, bit_depth, 0/*palette*/, interlace_type, + file_gamma, screen_gamma, 0/*sBIT*/, 1/*threshold test*/, name, + 0 /*no input precision*/, + 0 /*no scale16*/, 0 /*no expand16*/, 0 /*no background*/, 0 /*hence*/, + 0 /*no background gamma*/); +} + +static void +perform_gamma_threshold_tests(png_modifier *pm) +{ + png_byte colour_type = 0; + png_byte bit_depth = 0; + int palette_number = 0; + + /* Don't test more than one instance of each palette - it's pointless, in + * fact this test is somewhat excessive since libpng doesn't make this + * decision based on colour type or bit depth! + */ + while (next_format(&colour_type, &bit_depth, &palette_number)) + if (palette_number == 0) + { + double test_gamma = 1.0; + while (test_gamma >= .4) + { + /* There's little point testing the interlacing vs non-interlacing, + * but this can be set from the command line. + */ + gamma_threshold_test(pm, colour_type, bit_depth, pm->interlace_type, + test_gamma, 1/test_gamma); + test_gamma *= .95; + } + + /* And a special test for sRGB */ + gamma_threshold_test(pm, colour_type, bit_depth, pm->interlace_type, + .45455, 2.2); + + if (fail(pm)) + return; + } +} + +static void gamma_transform_test(png_modifier *pm, + PNG_CONST png_byte colour_type, PNG_CONST png_byte bit_depth, + PNG_CONST int palette_number, + PNG_CONST int interlace_type, PNG_CONST double file_gamma, + PNG_CONST double screen_gamma, PNG_CONST png_byte sbit, + PNG_CONST int use_input_precision, PNG_CONST int scale16) +{ + size_t pos = 0; + char name[64]; + + if (sbit != bit_depth && sbit != 0) + { + pos = safecat(name, sizeof name, pos, "sbit("); + pos = safecatn(name, sizeof name, pos, sbit); + pos = safecat(name, sizeof name, pos, ") "); + } + + else + pos = safecat(name, sizeof name, pos, "gamma "); + + if (scale16) + pos = safecat(name, sizeof name, pos, "16to8 "); + + pos = safecatd(name, sizeof name, pos, file_gamma, 3); + pos = safecat(name, sizeof name, pos, "->"); + pos = safecatd(name, sizeof name, pos, screen_gamma, 3); + + gamma_test(pm, colour_type, bit_depth, palette_number, interlace_type, + file_gamma, screen_gamma, sbit, 0, name, use_input_precision, + scale16, pm->test_gamma_expand16, 0 , 0, 0); +} + +static void perform_gamma_transform_tests(png_modifier *pm) +{ + png_byte colour_type = 0; + png_byte bit_depth = 0; + int palette_number = 0; + + while (next_format(&colour_type, &bit_depth, &palette_number)) + { + unsigned int i, j; + + for (i=0; ingamma_tests; ++i) for (j=0; jngamma_tests; ++j) + if (i != j) + { + gamma_transform_test(pm, colour_type, bit_depth, palette_number, + pm->interlace_type, 1/pm->gammas[i], pm->gammas[j], 0/*sBIT*/, + pm->use_input_precision, 0 /*do not scale16*/); + + if (fail(pm)) + return; + } + } +} + +static void perform_gamma_sbit_tests(png_modifier *pm) +{ + png_byte sbit; + + /* The only interesting cases are colour and grayscale, alpha is ignored here + * for overall speed. Only bit depths where sbit is less than the bit depth + * are tested. + */ + for (sbit=pm->sbitlow; sbit<(1<ngamma_tests; ++i) + { + unsigned int j; + + for (j=0; jngamma_tests; ++j) if (i != j) + { + gamma_transform_test(pm, colour_type, bit_depth, npalette, + pm->interlace_type, 1/pm->gammas[i], pm->gammas[j], + sbit, pm->use_input_precision_sbit, 0 /*scale16*/); + + if (fail(pm)) + return; + } + } + } + } +} + +/* Note that this requires a 16 bit source image but produces 8 bit output, so + * we only need the 16bit write support, but the 16 bit images are only + * generated if DO_16BIT is defined. + */ +#ifdef DO_16BIT +static void perform_gamma_scale16_tests(png_modifier *pm) +{ +# ifndef PNG_MAX_GAMMA_8 +# define PNG_MAX_GAMMA_8 11 +# endif + /* Include the alpha cases here. Note that sbit matches the internal value + * used by the library - otherwise we will get spurious errors from the + * internal sbit style approximation. + * + * The threshold test is here because otherwise the 16 to 8 conversion will + * proceed *without* gamma correction, and the tests above will fail (but not + * by much) - this could be fixed, it only appears with the -g option. + */ + unsigned int i, j; + for (i=0; ingamma_tests; ++i) + { + for (j=0; jngamma_tests; ++j) + { + if (i != j && + fabs(pm->gammas[j]/pm->gammas[i]-1) >= PNG_GAMMA_THRESHOLD) + { + gamma_transform_test(pm, 0, 16, 0, pm->interlace_type, + 1/pm->gammas[i], pm->gammas[j], PNG_MAX_GAMMA_8, + pm->use_input_precision_16to8, 1 /*scale16*/); + + if (fail(pm)) + return; + + gamma_transform_test(pm, 2, 16, 0, pm->interlace_type, + 1/pm->gammas[i], pm->gammas[j], PNG_MAX_GAMMA_8, + pm->use_input_precision_16to8, 1 /*scale16*/); + + if (fail(pm)) + return; + + gamma_transform_test(pm, 4, 16, 0, pm->interlace_type, + 1/pm->gammas[i], pm->gammas[j], PNG_MAX_GAMMA_8, + pm->use_input_precision_16to8, 1 /*scale16*/); + + if (fail(pm)) + return; + + gamma_transform_test(pm, 6, 16, 0, pm->interlace_type, + 1/pm->gammas[i], pm->gammas[j], PNG_MAX_GAMMA_8, + pm->use_input_precision_16to8, 1 /*scale16*/); + + if (fail(pm)) + return; + } + } + } +} +#endif /* 16 to 8 bit conversion */ + +#if defined PNG_READ_BACKGROUND_SUPPORTED ||\ + defined PNG_READ_ALPHA_MODE_SUPPORTED +static void gamma_composition_test(png_modifier *pm, + PNG_CONST png_byte colour_type, PNG_CONST png_byte bit_depth, + PNG_CONST int palette_number, + PNG_CONST int interlace_type, PNG_CONST double file_gamma, + PNG_CONST double screen_gamma, + PNG_CONST int use_input_precision, PNG_CONST int do_background, + PNG_CONST int expand_16) +{ + size_t pos = 0; + png_const_charp base; + double bg; + char name[128]; + png_color_16 background; + + /* Make up a name and get an appropriate background gamma value. */ + switch (do_background) + { + default: + base = ""; + bg = 4; /* should not be used */ + break; + case PNG_BACKGROUND_GAMMA_SCREEN: + base = " bckg(Screen):"; + bg = 1/screen_gamma; + break; + case PNG_BACKGROUND_GAMMA_FILE: + base = " bckg(File):"; + bg = file_gamma; + break; + case PNG_BACKGROUND_GAMMA_UNIQUE: + base = " bckg(Unique):"; + /* This tests the handling of a unique value, the math is such that the + * value tends to be <1, but is neither screen nor file (even if they + * match!) + */ + bg = (file_gamma + screen_gamma) / 3; + break; +#ifdef PNG_READ_ALPHA_MODE_SUPPORTED + case ALPHA_MODE_OFFSET + PNG_ALPHA_PNG: + base = " alpha(PNG)"; + bg = 4; /* should not be used */ + break; + case ALPHA_MODE_OFFSET + PNG_ALPHA_STANDARD: + base = " alpha(Porter-Duff)"; + bg = 4; /* should not be used */ + break; + case ALPHA_MODE_OFFSET + PNG_ALPHA_OPTIMIZED: + base = " alpha(Optimized)"; + bg = 4; /* should not be used */ + break; + case ALPHA_MODE_OFFSET + PNG_ALPHA_BROKEN: + base = " alpha(Broken)"; + bg = 4; /* should not be used */ + break; +#endif + } + + /* Use random background values - the background is always presented in the + * output space (8 or 16 bit components). + */ + if (expand_16 || bit_depth == 16) + { + png_uint_32 r = random_32(); + + background.red = (png_uint_16)r; + background.green = (png_uint_16)(r >> 16); + r = random_32(); + background.blue = (png_uint_16)r; + background.gray = (png_uint_16)(r >> 16); + } + + else /* 8 bit colors */ + { + png_uint_32 r = random_32(); + + background.red = (png_byte)r; + background.green = (png_byte)(r >> 8); + background.blue = (png_byte)(r >> 16); + background.gray = (png_byte)(r >> 24); + } + + background.index = 193; /* rgb(193,193,193) to detect errors */ + if (!(colour_type & PNG_COLOR_MASK_COLOR)) + { + /* Grayscale input, we do not convert to RGB (TBD), so we must set the + * background to gray - else libpng seems to fail. + */ + background.red = background.green = background.blue = background.gray; + } + + pos = safecat(name, sizeof name, pos, "gamma "); + pos = safecatd(name, sizeof name, pos, file_gamma, 3); + pos = safecat(name, sizeof name, pos, "->"); + pos = safecatd(name, sizeof name, pos, screen_gamma, 3); + + pos = safecat(name, sizeof name, pos, base); + if (do_background < ALPHA_MODE_OFFSET) + { + /* Include the background color and gamma in the name: */ + pos = safecat(name, sizeof name, pos, "("); + /* This assumes no expand gray->rgb - the current code won't handle that! + */ + if (colour_type & PNG_COLOR_MASK_COLOR) + { + pos = safecatn(name, sizeof name, pos, background.red); + pos = safecat(name, sizeof name, pos, ","); + pos = safecatn(name, sizeof name, pos, background.green); + pos = safecat(name, sizeof name, pos, ","); + pos = safecatn(name, sizeof name, pos, background.blue); + } + else + pos = safecatn(name, sizeof name, pos, background.gray); + pos = safecat(name, sizeof name, pos, ")^"); + pos = safecatd(name, sizeof name, pos, bg, 3); + } + + gamma_test(pm, colour_type, bit_depth, palette_number, interlace_type, + file_gamma, screen_gamma, 0/*sBIT*/, 0, name, use_input_precision, + 0/*strip 16*/, expand_16, do_background, &background, bg); +} + + +static void +perform_gamma_composition_tests(png_modifier *pm, int do_background, + int expand_16) +{ + png_byte colour_type = 0; + png_byte bit_depth = 0; + int palette_number = 0; + + /* Skip the non-alpha cases - there is no setting of a transparency colour at + * present. + */ + while (next_format(&colour_type, &bit_depth, &palette_number)) + if ((colour_type & PNG_COLOR_MASK_ALPHA) != 0) + { + unsigned int i, j; + + /* Don't skip the i==j case here - it's relevant. */ + for (i=0; ingamma_tests; ++i) for (j=0; jngamma_tests; ++j) + { + gamma_composition_test(pm, colour_type, bit_depth, palette_number, + pm->interlace_type, 1/pm->gammas[i], pm->gammas[j], + pm->use_input_precision, do_background, expand_16); + + if (fail(pm)) + return; + } + } +} +#endif /* READ_BACKGROUND || READ_ALPHA_MODE */ + +static void +init_gamma_errors(png_modifier *pm) +{ + pm->error_gray_2 = pm->error_gray_4 = pm->error_gray_8 = 0; + pm->error_color_8 = 0; + pm->error_indexed = 0; + pm->error_gray_16 = pm->error_color_16 = 0; +} + +static void +summarize_gamma_errors(png_modifier *pm, png_const_charp who, int low_bit_depth) +{ + if (who) + printf("Gamma correction with %s:\n", who); + + if (low_bit_depth) + { + printf(" 2 bit gray: %.5f\n", pm->error_gray_2); + printf(" 4 bit gray: %.5f\n", pm->error_gray_4); + printf(" 8 bit gray: %.5f\n", pm->error_gray_8); + printf(" 8 bit color: %.5f\n", pm->error_color_8); + printf(" indexed: %.5f\n", pm->error_indexed); + } + +#ifdef DO_16BIT + printf(" 16 bit gray: %.5f\n", pm->error_gray_16); + printf(" 16 bit color: %.5f\n", pm->error_color_16); +#endif +} + +static void +perform_gamma_test(png_modifier *pm, int summary) +{ + /*TODO: remove this*/ + /* Save certain values for the temporary overrides below. */ + unsigned int calculations_use_input_precision = + pm->calculations_use_input_precision; + double maxout8 = pm->maxout8; + + /* First some arbitrary no-transform tests: */ + if (!pm->this.speed && pm->test_gamma_threshold) + { + perform_gamma_threshold_tests(pm); + + if (fail(pm)) + return; + } + + /* Now some real transforms. */ + if (pm->test_gamma_transform) + { + init_gamma_errors(pm); + /*TODO: remove this. Necessary because the current libpng + * implementation works in 8 bits: + */ + if (pm->test_gamma_expand16) + pm->calculations_use_input_precision = 1; + perform_gamma_transform_tests(pm); + if (!calculations_use_input_precision) + pm->calculations_use_input_precision = 0; + + if (summary) + { + printf("Gamma correction error summary\n\n"); + printf("The printed value is the maximum error in the pixel values\n"); + printf("calculated by the libpng gamma correction code. The error\n"); + printf("is calculated as the difference between the output pixel\n"); + printf("value (always an integer) and the ideal value from the\n"); + printf("libpng specification (typically not an integer).\n\n"); + + printf("Expect this value to be less than .5 for 8 bit formats,\n"); + printf("less than 1 for formats with fewer than 8 bits and a small\n"); + printf("number (typically less than 5) for the 16 bit formats.\n"); + printf("For performance reasons the value for 16 bit formats\n"); + printf("increases when the image file includes an sBIT chunk.\n\n"); + + summarize_gamma_errors(pm, 0/*who*/, 1); + } + } + + /* The sbit tests produce much larger errors: */ + if (pm->test_gamma_sbit) + { + init_gamma_errors(pm); + perform_gamma_sbit_tests(pm); + + if (summary) + summarize_gamma_errors(pm, "sBIT", pm->sbitlow < 8U); + } + +#ifdef DO_16BIT /* Should be READ_16BIT_SUPPORTED */ + if (pm->test_gamma_scale16) + { + /* The 16 to 8 bit strip operations: */ + init_gamma_errors(pm); + perform_gamma_scale16_tests(pm); + + if (summary) + { + printf("Gamma correction with 16 to 8 bit reduction:\n"); + printf(" 16 bit gray: %.5f\n", pm->error_gray_16); + printf(" 16 bit color: %.5f\n", pm->error_color_16); + } + } +#endif + +#ifdef PNG_READ_BACKGROUND_SUPPORTED + if (pm->test_gamma_background) + { + init_gamma_errors(pm); + + /*TODO: remove this. Necessary because the current libpng + * implementation works in 8 bits: + */ + if (pm->test_gamma_expand16) + { + pm->calculations_use_input_precision = 1; + pm->maxout8 = .499; /* because the 16 bit background is smashed */ + } + perform_gamma_composition_tests(pm, PNG_BACKGROUND_GAMMA_UNIQUE, + pm->test_gamma_expand16); + if (!calculations_use_input_precision) + pm->calculations_use_input_precision = 0; + pm->maxout8 = maxout8; + + if (summary) + summarize_gamma_errors(pm, "background", 1); + } +#endif + +#ifdef PNG_READ_ALPHA_MODE_SUPPORTED + if (pm->test_gamma_alpha_mode) + { + int do_background; + + init_gamma_errors(pm); + + /*TODO: remove this. Necessary because the current libpng + * implementation works in 8 bits: + */ + if (pm->test_gamma_expand16) + pm->calculations_use_input_precision = 1; + for (do_background = ALPHA_MODE_OFFSET + PNG_ALPHA_STANDARD; + do_background <= ALPHA_MODE_OFFSET + PNG_ALPHA_BROKEN && !fail(pm); + ++do_background) + perform_gamma_composition_tests(pm, do_background, + pm->test_gamma_expand16); + if (!calculations_use_input_precision) + pm->calculations_use_input_precision = 0; + + if (summary) + summarize_gamma_errors(pm, "alpha mode", 1); + } +#endif +} +#endif /* PNG_READ_GAMMA_SUPPORTED */ + +/* INTERLACE MACRO VALIDATION */ +/* This is copied verbatim from the specification, it is simply the pass + * number in which each pixel in each 8x8 tile appears. The array must + * be indexed adam7[y][x] and notice that the pass numbers are based at + * 1, not 0 - the base libpng uses. + */ +static PNG_CONST +png_byte adam7[8][8] = +{ + { 1,6,4,6,2,6,4,6 }, + { 7,7,7,7,7,7,7,7 }, + { 5,6,5,6,5,6,5,6 }, + { 7,7,7,7,7,7,7,7 }, + { 3,6,4,6,3,6,4,6 }, + { 7,7,7,7,7,7,7,7 }, + { 5,6,5,6,5,6,5,6 }, + { 7,7,7,7,7,7,7,7 } +}; + +/* This routine validates all the interlace support macros in png.h for + * a variety of valid PNG widths and heights. It uses a number of similarly + * named internal routines that feed off the above array. + */ +static png_uint_32 +png_pass_start_row(int pass) +{ + int x, y; + ++pass; + for (y=0; y<8; ++y) for (x=0; x<8; ++x) if (adam7[y][x] == pass) + return y; + return 0xf; +} + +static png_uint_32 +png_pass_start_col(int pass) +{ + int x, y; + ++pass; + for (x=0; x<8; ++x) for (y=0; y<8; ++y) if (adam7[y][x] == pass) + return x; + return 0xf; +} + +static int +png_pass_row_shift(int pass) +{ + int x, y, base=(-1), inc=8; + ++pass; + for (y=0; y<8; ++y) for (x=0; x<8; ++x) if (adam7[y][x] == pass) + { + if (base == (-1)) + base = y; + else if (base == y) + {} + else if (inc == y-base) + base=y; + else if (inc == 8) + inc = y-base, base=y; + else if (inc != y-base) + return 0xff; /* error - more than one 'inc' value! */ + } + + if (base == (-1)) return 0xfe; /* error - no row in pass! */ + + /* The shift is always 1, 2 or 3 - no pass has all the rows! */ + switch (inc) + { +case 2: return 1; +case 4: return 2; +case 8: return 3; +default: break; + } + + /* error - unrecognized 'inc' */ + return (inc << 8) + 0xfd; +} + +static int +png_pass_col_shift(int pass) +{ + int x, y, base=(-1), inc=8; + ++pass; + for (x=0; x<8; ++x) for (y=0; y<8; ++y) if (adam7[y][x] == pass) + { + if (base == (-1)) + base = x; + else if (base == x) + {} + else if (inc == x-base) + base=x; + else if (inc == 8) + inc = x-base, base=x; + else if (inc != x-base) + return 0xff; /* error - more than one 'inc' value! */ + } + + if (base == (-1)) return 0xfe; /* error - no row in pass! */ + + /* The shift is always 1, 2 or 3 - no pass has all the rows! */ + switch (inc) + { +case 1: return 0; /* pass 7 has all the columns */ +case 2: return 1; +case 4: return 2; +case 8: return 3; +default: break; + } + + /* error - unrecognized 'inc' */ + return (inc << 8) + 0xfd; +} + +static png_uint_32 +png_row_from_pass_row(png_uint_32 yIn, int pass) +{ + /* By examination of the array: */ + switch (pass) + { +case 0: return yIn * 8; +case 1: return yIn * 8; +case 2: return yIn * 8 + 4; +case 3: return yIn * 4; +case 4: return yIn * 4 + 2; +case 5: return yIn * 2; +case 6: return yIn * 2 + 1; +default: break; + } + + return 0xff; /* bad pass number */ +} + +static png_uint_32 +png_col_from_pass_col(png_uint_32 xIn, int pass) +{ + /* By examination of the array: */ + switch (pass) + { +case 0: return xIn * 8; +case 1: return xIn * 8 + 4; +case 2: return xIn * 4; +case 3: return xIn * 4 + 2; +case 4: return xIn * 2; +case 5: return xIn * 2 + 1; +case 6: return xIn; +default: break; + } + + return 0xff; /* bad pass number */ +} + +static int +png_row_in_interlace_pass(png_uint_32 y, int pass) +{ + /* Is row 'y' in pass 'pass'? */ + int x; + y &= 7; + ++pass; + for (x=0; x<8; ++x) if (adam7[y][x] == pass) + return 1; + + return 0; +} + +static int +png_col_in_interlace_pass(png_uint_32 x, int pass) +{ + /* Is column 'x' in pass 'pass'? */ + int y; + x &= 7; + ++pass; + for (y=0; y<8; ++y) if (adam7[y][x] == pass) + return 1; + + return 0; +} + +static png_uint_32 +png_pass_rows(png_uint_32 height, int pass) +{ + png_uint_32 tiles = height>>3; + png_uint_32 rows = 0; + unsigned int x, y; + + height &= 7; + ++pass; + for (y=0; y<8; ++y) for (x=0; x<8; ++x) if (adam7[y][x] == pass) + { + rows += tiles; + if (y < height) ++rows; + break; /* i.e. break the 'x', column, loop. */ + } + + return rows; +} + +static png_uint_32 +png_pass_cols(png_uint_32 width, int pass) +{ + png_uint_32 tiles = width>>3; + png_uint_32 cols = 0; + unsigned int x, y; + + width &= 7; + ++pass; + for (x=0; x<8; ++x) for (y=0; y<8; ++y) if (adam7[y][x] == pass) + { + cols += tiles; + if (x < width) ++cols; + break; /* i.e. break the 'y', row, loop. */ + } + + return cols; +} + +static void +perform_interlace_macro_validation(void) +{ + /* The macros to validate, first those that depend only on pass: + * + * PNG_PASS_START_ROW(pass) + * PNG_PASS_START_COL(pass) + * PNG_PASS_ROW_SHIFT(pass) + * PNG_PASS_COL_SHIFT(pass) + */ + int pass; + + for (pass=0; pass<7; ++pass) + { + png_uint_32 m, f, v; + + m = PNG_PASS_START_ROW(pass); + f = png_pass_start_row(pass); + if (m != f) + { + fprintf(stderr, "PNG_PASS_START_ROW(%d) = %u != %x\n", pass, m, f); + exit(1); + } + + m = PNG_PASS_START_COL(pass); + f = png_pass_start_col(pass); + if (m != f) + { + fprintf(stderr, "PNG_PASS_START_COL(%d) = %u != %x\n", pass, m, f); + exit(1); + } + + m = PNG_PASS_ROW_SHIFT(pass); + f = png_pass_row_shift(pass); + if (m != f) + { + fprintf(stderr, "PNG_PASS_ROW_SHIFT(%d) = %u != %x\n", pass, m, f); + exit(1); + } + + m = PNG_PASS_COL_SHIFT(pass); + f = png_pass_col_shift(pass); + if (m != f) + { + fprintf(stderr, "PNG_PASS_COL_SHIFT(%d) = %u != %x\n", pass, m, f); + exit(1); + } + + /* Macros that depend on the image or sub-image height too: + * + * PNG_PASS_ROWS(height, pass) + * PNG_PASS_COLS(width, pass) + * PNG_ROW_FROM_PASS_ROW(yIn, pass) + * PNG_COL_FROM_PASS_COL(xIn, pass) + * PNG_ROW_IN_INTERLACE_PASS(y, pass) + * PNG_COL_IN_INTERLACE_PASS(x, pass) + */ + for (v=0;;) + { + /* First the base 0 stuff: */ + m = PNG_ROW_FROM_PASS_ROW(v, pass); + f = png_row_from_pass_row(v, pass); + if (m != f) + { + fprintf(stderr, "PNG_ROW_FROM_PASS_ROW(%u, %d) = %u != %x\n", + v, pass, m, f); + exit(1); + } + + m = PNG_COL_FROM_PASS_COL(v, pass); + f = png_col_from_pass_col(v, pass); + if (m != f) + { + fprintf(stderr, "PNG_COL_FROM_PASS_COL(%u, %d) = %u != %x\n", + v, pass, m, f); + exit(1); + } + + m = PNG_ROW_IN_INTERLACE_PASS(v, pass); + f = png_row_in_interlace_pass(v, pass); + if (m != f) + { + fprintf(stderr, "PNG_ROW_IN_INTERLACE_PASS(%u, %d) = %u != %x\n", + v, pass, m, f); + exit(1); + } + + m = PNG_COL_IN_INTERLACE_PASS(v, pass); + f = png_col_in_interlace_pass(v, pass); + if (m != f) + { + fprintf(stderr, "PNG_COL_IN_INTERLACE_PASS(%u, %d) = %u != %x\n", + v, pass, m, f); + exit(1); + } + + /* Then the base 1 stuff: */ + ++v; + m = PNG_PASS_ROWS(v, pass); + f = png_pass_rows(v, pass); + if (m != f) + { + fprintf(stderr, "PNG_PASS_ROWS(%u, %d) = %u != %x\n", + v, pass, m, f); + exit(1); + } + + m = PNG_PASS_COLS(v, pass); + f = png_pass_cols(v, pass); + if (m != f) + { + fprintf(stderr, "PNG_PASS_COLS(%u, %d) = %u != %x\n", + v, pass, m, f); + exit(1); + } + + /* Move to the next v - the stepping algorithm starts skipping + * values above 1024. + */ + if (v > 1024) + { + if (v == PNG_UINT_31_MAX) + break; + + v = (v << 1) ^ v; + if (v >= PNG_UINT_31_MAX) + v = PNG_UINT_31_MAX-1; + } + } + } +} + +/* Test color encodings. These values are back-calculated from the published + * chromaticities. The values are accurate to about 14 decimal places; 15 are + * given. These values are much more accurate than the ones given in the spec, + * which typically don't exceed 4 decimal places. This allows testing of the + * libpng code to its theoretical accuracy of 4 decimal places. (If pngvalid + * used the published errors the 'slack' permitted would have to be +/-.5E-4 or + * more.) + * + * The png_modifier code assumes that encodings[0] is sRGB and treats it + * specially: do not change the first entry in this list! + */ +static PNG_CONST color_encoding test_encodings[] = +{ +/* sRGB: must be first in this list! */ +/*gamma:*/ { 1/2.2, +/*red: */ { 0.412390799265959, 0.212639005871510, 0.019330818715592 }, +/*green:*/ { 0.357584339383878, 0.715168678767756, 0.119194779794626 }, +/*blue: */ { 0.180480788401834, 0.072192315360734, 0.950532152249660} }, +/* Kodak ProPhoto (wide gamut) */ +/*gamma:*/ { 1/1.6 /*approximate: uses 1.8 power law compared to sRGB 2.4*/, +/*red: */ { 0.797760489672303, 0.288071128229293, 0.000000000000000 }, +/*green:*/ { 0.135185837175740, 0.711843217810102, 0.000000000000000 }, +/*blue: */ { 0.031349349581525, 0.000085653960605, 0.825104602510460} }, +/* Adobe RGB (1998) */ +/*gamma:*/ { 1/(2+51./256), +/*red: */ { 0.576669042910131, 0.297344975250536, 0.027031361386412 }, +/*green:*/ { 0.185558237906546, 0.627363566255466, 0.070688852535827 }, +/*blue: */ { 0.188228646234995, 0.075291458493998, 0.991337536837639} }, +/* Adobe Wide Gamut RGB */ +/*gamma:*/ { 1/(2+51./256), +/*red: */ { 0.716500716779386, 0.258728243040113, 0.000000000000000 }, +/*green:*/ { 0.101020574397477, 0.724682314948566, 0.051211818965388 }, +/*blue: */ { 0.146774385252705, 0.016589442011321, 0.773892783545073} }, +}; + +/* signal handler + * + * This attempts to trap signals and escape without crashing. It needs a + * context pointer so that it can throw an exception (call longjmp) to recover + * from the condition; this is handled by making the png_modifier used by 'main' + * into a global variable. + */ +static png_modifier pm; + +static void signal_handler(int signum) +{ + + size_t pos = 0; + char msg[64]; + + pos = safecat(msg, sizeof msg, pos, "caught signal: "); + + switch (signum) + { + case SIGABRT: + pos = safecat(msg, sizeof msg, pos, "abort"); + break; + + case SIGFPE: + pos = safecat(msg, sizeof msg, pos, "floating point exception"); + break; + + case SIGILL: + pos = safecat(msg, sizeof msg, pos, "illegal instruction"); + break; + + case SIGINT: + pos = safecat(msg, sizeof msg, pos, "interrupt"); + break; + + case SIGSEGV: + pos = safecat(msg, sizeof msg, pos, "invalid memory access"); + break; + + case SIGTERM: + pos = safecat(msg, sizeof msg, pos, "termination request"); + break; + + default: + pos = safecat(msg, sizeof msg, pos, "unknown "); + pos = safecatn(msg, sizeof msg, pos, signum); + break; + } + + store_log(&pm.this, NULL/*png_structp*/, msg, 1/*error*/); + + /* And finally throw an exception so we can keep going, unless this is + * SIGTERM in which case stop now. + */ + if (signum != SIGTERM) + { + struct exception_context *the_exception_context = + &pm.this.exception_context; + + Throw &pm.this; + } + + else + exit(1); +} + +/* main program */ +int main(int argc, PNG_CONST char **argv) +{ + volatile int summary = 1; /* Print the error summary at the end */ + volatile int memstats = 0; /* Print memory statistics at the end */ + + /* Create the given output file on success: */ + PNG_CONST char *volatile touch = NULL; + + /* This is an array of standard gamma values (believe it or not I've seen + * every one of these mentioned somewhere.) + * + * In the following list the most useful values are first! + */ + static double + gammas[]={2.2, 1.0, 2.2/1.45, 1.8, 1.5, 2.4, 2.5, 2.62, 2.9}; + + /* This records the command and arguments: */ + size_t cp = 0; + char command[1024]; + + context(&pm.this, fault); + + /* Add appropriate signal handlers, just the ANSI specified ones: */ + signal(SIGABRT, signal_handler); + signal(SIGFPE, signal_handler); + signal(SIGILL, signal_handler); + signal(SIGINT, signal_handler); + signal(SIGSEGV, signal_handler); + signal(SIGTERM, signal_handler); + +#ifdef HAVE_FEENABLEEXCEPT + /* Only required to enable FP exceptions on platforms where they start off + * disabled; this is not necessary but if it is not done pngvalid will likely + * end up ignoring FP conditions that other platforms fault. + */ + feenableexcept(FE_DIVBYZERO | FE_INVALID | FE_OVERFLOW); +#endif + + modifier_init(&pm); + + /* Preallocate the image buffer, because we know how big it needs to be, + * note that, for testing purposes, it is deliberately mis-aligned by tag + * bytes either side. All rows have an additional five bytes of padding for + * overwrite checking. + */ + store_ensure_image(&pm.this, NULL, 2, TRANSFORM_ROWMAX, TRANSFORM_HEIGHTMAX); + + /* Don't give argv[0], it's normally some horrible libtool string: */ + cp = safecat(command, sizeof command, cp, "pngvalid"); + + /* Default to error on warning: */ + pm.this.treat_warnings_as_errors = 1; + + /* Store the test gammas */ + pm.gammas = gammas; + pm.ngammas = (sizeof gammas) / (sizeof gammas[0]); + pm.ngamma_tests = 0; /* default to off */ + + /* And the test encodings */ + pm.encodings = test_encodings; + pm.nencodings = (sizeof test_encodings) / (sizeof test_encodings[0]); + + pm.sbitlow = 8U; /* because libpng doesn't do sBIT below 8! */ + /* The following allows results to pass if they correspond to anything in the + * transformed range [input-.5,input+.5]; this is is required because of the + * way libpng treates the 16_TO_8 flag when building the gamma tables. + * + * TODO: review this + */ + pm.use_input_precision_16to8 = 1U; + + /* Some default values (set the behavior for 'make check' here). + * These values simply control the maximum error permitted in the gamma + * transformations. The practial limits for human perception are described + * below (the setting for maxpc16), however for 8 bit encodings it isn't + * possible to meet the accepted capabilities of human vision - i.e. 8 bit + * images can never be good enough, regardless of encoding. + */ + pm.maxout8 = .1; /* Arithmetic error in *encoded* value */ + pm.maxabs8 = .00005; /* 1/20000 */ + pm.maxcalc8 = .004; /* +/-1 in 8 bits for compose errors */ + pm.maxpc8 = .499; /* I.e., .499% fractional error */ + pm.maxout16 = .499; /* Error in *encoded* value */ + pm.maxabs16 = .00005;/* 1/20000 */ + pm.maxcalc16 =.000015;/* +/-1 in 16 bits for compose errors */ + + /* NOTE: this is a reasonable perceptual limit. We assume that humans can + * perceive light level differences of 1% over a 100:1 range, so we need to + * maintain 1 in 10000 accuracy (in linear light space), which is what the + * following guarantees. It also allows significantly higher errors at + * higher 16 bit values, which is important for performance. The actual + * maximum 16 bit error is about +/-1.9 in the fixed point implementation but + * this is only allowed for values >38149 by the following: + */ + pm.maxpc16 = .005; /* I.e., 1/200% - 1/20000 */ + + /* Now parse the command line options. */ + while (--argc >= 1) + { + int catmore = 0; /* Set if the argument has an argument. */ + + /* Record each argument for posterity: */ + cp = safecat(command, sizeof command, cp, " "); + cp = safecat(command, sizeof command, cp, *++argv); + + if (strcmp(*argv, "-v") == 0) + pm.this.verbose = 1; + + else if (strcmp(*argv, "-l") == 0) + pm.log = 1; + + else if (strcmp(*argv, "-q") == 0) + summary = pm.this.verbose = pm.log = 0; + + else if (strcmp(*argv, "-w") == 0) + pm.this.treat_warnings_as_errors = 0; + + else if (strcmp(*argv, "--speed") == 0) + pm.this.speed = 1, pm.ngamma_tests = pm.ngammas, pm.test_standard = 0, + summary = 0; + + else if (strcmp(*argv, "--memory") == 0) + memstats = 1; + + else if (strcmp(*argv, "--size") == 0) + pm.test_size = 1; + + else if (strcmp(*argv, "--nosize") == 0) + pm.test_size = 0; + + else if (strcmp(*argv, "--standard") == 0) + pm.test_standard = 1; + + else if (strcmp(*argv, "--nostandard") == 0) + pm.test_standard = 0; + + else if (strcmp(*argv, "--transform") == 0) + pm.test_transform = 1; + + else if (strcmp(*argv, "--notransform") == 0) + pm.test_transform = 0; + +#ifdef PNG_READ_TRANSFORMS_SUPPORTED + else if (strncmp(*argv, "--transform-disable=", + sizeof "--transform-disable") == 0) + { + pm.test_transform = 1; + transform_disable(*argv + sizeof "--transform-disable"); + } + + else if (strncmp(*argv, "--transform-enable=", + sizeof "--transform-enable") == 0) + { + pm.test_transform = 1; + transform_enable(*argv + sizeof "--transform-enable"); + } +#endif /* PNG_READ_TRANSFORMS_SUPPORTED */ + + else if (strcmp(*argv, "--gamma") == 0) + { + /* Just do two gamma tests here (2.2 and linear) for speed: */ + pm.ngamma_tests = 2U; + pm.test_gamma_threshold = 1; + pm.test_gamma_transform = 1; + pm.test_gamma_sbit = 1; + pm.test_gamma_scale16 = 1; + pm.test_gamma_background = 1; + pm.test_gamma_alpha_mode = 1; + } + + else if (strcmp(*argv, "--nogamma") == 0) + pm.ngamma_tests = 0; + + else if (strcmp(*argv, "--gamma-threshold") == 0) + pm.ngamma_tests = 2U, pm.test_gamma_threshold = 1; + + else if (strcmp(*argv, "--nogamma-threshold") == 0) + pm.test_gamma_threshold = 0; + + else if (strcmp(*argv, "--gamma-transform") == 0) + pm.ngamma_tests = 2U, pm.test_gamma_transform = 1; + + else if (strcmp(*argv, "--nogamma-transform") == 0) + pm.test_gamma_transform = 0; + + else if (strcmp(*argv, "--gamma-sbit") == 0) + pm.ngamma_tests = 2U, pm.test_gamma_sbit = 1; + + else if (strcmp(*argv, "--nogamma-sbit") == 0) + pm.test_gamma_sbit = 0; + + else if (strcmp(*argv, "--gamma-16-to-8") == 0) + pm.ngamma_tests = 2U, pm.test_gamma_scale16 = 1; + + else if (strcmp(*argv, "--nogamma-16-to-8") == 0) + pm.test_gamma_scale16 = 0; + + else if (strcmp(*argv, "--gamma-background") == 0) + pm.ngamma_tests = 2U, pm.test_gamma_background = 1; + + else if (strcmp(*argv, "--nogamma-background") == 0) + pm.test_gamma_background = 0; + + else if (strcmp(*argv, "--gamma-alpha-mode") == 0) + pm.ngamma_tests = 2U, pm.test_gamma_alpha_mode = 1; + + else if (strcmp(*argv, "--nogamma-alpha-mode") == 0) + pm.test_gamma_alpha_mode = 0; + + else if (strcmp(*argv, "--expand16") == 0) + pm.test_gamma_expand16 = 1; + + else if (strcmp(*argv, "--noexpand16") == 0) + pm.test_gamma_expand16 = 0; + + else if (strcmp(*argv, "--more-gammas") == 0) + pm.ngamma_tests = 3U; + + else if (strcmp(*argv, "--all-gammas") == 0) + pm.ngamma_tests = pm.ngammas; + + else if (strcmp(*argv, "--progressive-read") == 0) + pm.this.progressive = 1; + + else if (strcmp(*argv, "--use-update-info") == 0) + ++pm.use_update_info; /* Can call multiple times */ + + else if (strcmp(*argv, "--interlace") == 0) + pm.interlace_type = PNG_INTERLACE_ADAM7; + + else if (strcmp(*argv, "--use-input-precision") == 0) + pm.use_input_precision = 1; + + else if (strcmp(*argv, "--calculations-use-input-precision") == 0) + pm.calculations_use_input_precision = 1; + + else if (strcmp(*argv, "--assume-16-bit-calculations") == 0) + pm.assume_16_bit_calculations = 1; + + else if (strcmp(*argv, "--calculations-follow-bit-depth") == 0) + pm.calculations_use_input_precision = + pm.assume_16_bit_calculations = 0; + + else if (strcmp(*argv, "--exhaustive") == 0) + pm.test_exhaustive = 1; + + else if (argc > 1 && strcmp(*argv, "--sbitlow") == 0) + --argc, pm.sbitlow = (png_byte)atoi(*++argv), catmore = 1; + + else if (argc > 1 && strcmp(*argv, "--touch") == 0) + --argc, touch = *++argv, catmore = 1; + + else if (argc > 1 && strncmp(*argv, "--max", 5) == 0) + { + --argc; + + if (strcmp(5+*argv, "abs8") == 0) + pm.maxabs8 = atof(*++argv); + + else if (strcmp(5+*argv, "abs16") == 0) + pm.maxabs16 = atof(*++argv); + + else if (strcmp(5+*argv, "calc8") == 0) + pm.maxcalc8 = atof(*++argv); + + else if (strcmp(5+*argv, "calc16") == 0) + pm.maxcalc16 = atof(*++argv); + + else if (strcmp(5+*argv, "out8") == 0) + pm.maxout8 = atof(*++argv); + + else if (strcmp(5+*argv, "out16") == 0) + pm.maxout16 = atof(*++argv); + + else if (strcmp(5+*argv, "pc8") == 0) + pm.maxpc8 = atof(*++argv); + + else if (strcmp(5+*argv, "pc16") == 0) + pm.maxpc16 = atof(*++argv); + + else + { + fprintf(stderr, "pngvalid: %s: unknown 'max' option\n", *argv); + exit(1); + } + + catmore = 1; + } + + else if (strcmp(*argv, "--log8") == 0) + --argc, pm.log8 = atof(*++argv), catmore = 1; + + else if (strcmp(*argv, "--log16") == 0) + --argc, pm.log16 = atof(*++argv), catmore = 1; + + else + { + fprintf(stderr, "pngvalid: %s: unknown argument\n", *argv); + exit(1); + } + + if (catmore) /* consumed an extra *argv */ + { + cp = safecat(command, sizeof command, cp, " "); + cp = safecat(command, sizeof command, cp, *argv); + } + } + + /* If pngvalid is run with no arguments default to a reasonable set of the + * tests. + */ + if (pm.test_standard == 0 && pm.test_size == 0 && pm.test_transform == 0 && + pm.ngamma_tests == 0) + { + /* Make this do all the tests done in the test shell scripts with the same + * parameters, where possible. The limitation is that all the progressive + * read and interlace stuff has to be done in separate runs, so only the + * basic 'standard' and 'size' tests are done. + */ + pm.test_standard = 1; + pm.test_size = 1; + pm.test_transform = 1; + pm.ngamma_tests = 2U; + } + + if (pm.ngamma_tests > 0 && + pm.test_gamma_threshold == 0 && pm.test_gamma_transform == 0 && + pm.test_gamma_sbit == 0 && pm.test_gamma_scale16 == 0 && + pm.test_gamma_background == 0 && pm.test_gamma_alpha_mode == 0) + { + pm.test_gamma_threshold = 1; + pm.test_gamma_transform = 1; + pm.test_gamma_sbit = 1; + pm.test_gamma_scale16 = 1; + pm.test_gamma_background = 1; + pm.test_gamma_alpha_mode = 1; + } + + else if (pm.ngamma_tests == 0) + { + /* Nothing to test so turn everything off: */ + pm.test_gamma_threshold = 0; + pm.test_gamma_transform = 0; + pm.test_gamma_sbit = 0; + pm.test_gamma_scale16 = 0; + pm.test_gamma_background = 0; + pm.test_gamma_alpha_mode = 0; + } + + Try + { + /* Make useful base images */ + make_transform_images(&pm.this); + + /* Perform the standard and gamma tests. */ + if (pm.test_standard) + { + perform_interlace_macro_validation(); + perform_formatting_test(&pm.this); + perform_standard_test(&pm); + perform_error_test(&pm); + } + + /* Various oddly sized images: */ + if (pm.test_size) + { + make_size_images(&pm.this); + perform_size_test(&pm); + } + +#ifdef PNG_READ_TRANSFORMS_SUPPORTED + /* Combinatorial transforms: */ + if (pm.test_transform) + perform_transform_test(&pm); +#endif /* PNG_READ_TRANSFORMS_SUPPORTED */ + +#ifdef PNG_READ_GAMMA_SUPPORTED + if (pm.ngamma_tests > 0) + perform_gamma_test(&pm, summary); +#endif + } + + Catch(fault) + { + fprintf(stderr, "pngvalid: test aborted (probably failed in cleanup)\n"); + if (!pm.this.verbose) + { + if (pm.this.error[0] != 0) + fprintf(stderr, "pngvalid: first error: %s\n", pm.this.error); + + fprintf(stderr, "pngvalid: run with -v to see what happened\n"); + } + exit(1); + } + + if (summary) + { + printf("%s: %s (%s point arithmetic)\n", + (pm.this.nerrors || (pm.this.treat_warnings_as_errors && + pm.this.nwarnings)) ? "FAIL" : "PASS", + command, +#if defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) || PNG_LIBPNG_VER < 10500 + "floating" +#else + "fixed" +#endif + ); + } + + if (memstats) + { + printf("Allocated memory statistics (in bytes):\n" + "\tread %lu maximum single, %lu peak, %lu total\n" + "\twrite %lu maximum single, %lu peak, %lu total\n", + (unsigned long)pm.this.read_memory_pool.max_max, + (unsigned long)pm.this.read_memory_pool.max_limit, + (unsigned long)pm.this.read_memory_pool.max_total, + (unsigned long)pm.this.write_memory_pool.max_max, + (unsigned long)pm.this.write_memory_pool.max_limit, + (unsigned long)pm.this.write_memory_pool.max_total); + } + + /* Do this here to provoke memory corruption errors in memory not directly + * allocated by libpng - not a complete test, but better than nothing. + */ + store_delete(&pm.this); + + /* Error exit if there are any errors, and maybe if there are any + * warnings. + */ + if (pm.this.nerrors || (pm.this.treat_warnings_as_errors && + pm.this.nwarnings)) + { + if (!pm.this.verbose) + fprintf(stderr, "pngvalid: %s\n", pm.this.error); + + fprintf(stderr, "pngvalid: %d errors, %d warnings\n", pm.this.nerrors, + pm.this.nwarnings); + + exit(1); + } + + /* Success case. */ + if (touch != NULL) + { + FILE *fsuccess = fopen(touch, "wt"); + + if (fsuccess != NULL) + { + int error = 0; + fprintf(fsuccess, "PNG validation succeeded\n"); + fflush(fsuccess); + error = ferror(fsuccess); + + if (fclose(fsuccess) || error) + { + fprintf(stderr, "%s: write failed\n", touch); + exit(1); + } + } + } + + return 0; +} diff -ru4NwbB libpng-1.5.6/example.c libpng-1.5.7rc01/example.c --- libpng-1.5.6/example.c 2011-11-02 22:42:50.387042477 -0500 +++ libpng-1.5.7rc01/example.c 2011-12-01 09:01:18.260807501 -0600 @@ -1,20 +1,21 @@ #if 0 /* in case someone actually tries to compile this */ /* example.c - an example of using libpng - * Last changed in libpng 1.5.6 [(PENDING RELEASE)] - * This file has been placed in the public domain by the authors. + * Last changed in libpng 1.5.7 [(PENDING RELEASE)] * Maintained 1998-2011 Glenn Randers-Pehrson - * Maintained 1996, 1997 Andreas Dilger) - * Written 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) + * Maintained 1996, 1997 Andreas Dilger + * Written 1995, 1996 Guy Eric Schalnat, Group 42, Inc. */ /* This is an example of how to use libpng to read and write PNG files. * The file libpng-manual.txt is much more verbose then this. If you have not * read it, do so first. This was designed to be a starting point of an * implementation. This is not officially part of libpng, is hereby placed * in the public domain, and therefore does not require a copyright notice. + * To the extent possible under law, the authors have waived all copyright and + * related or neighboring rights to this file. * * This file does not currently compile, because it is missing certain * parts, like allocating memory to hold an image. You will have to * supply these parts to get it to compile. For an example of a minimal diff -ru4NwbB libpng-1.5.6/png.c libpng-1.5.7rc01/png.c --- libpng-1.5.6/png.c 2011-11-02 22:42:50.399590772 -0500 +++ libpng-1.5.7rc01/png.c 2011-12-01 09:01:18.273058897 -0600 @@ -1,8 +1,8 @@ /* png.c - location for general purpose libpng functions * - * Last changed in libpng 1.5.6 [(PENDING RELEASE)] + * Last changed in libpng 1.5.7 [(PENDING RELEASE)] * Copyright (c) 1998-2011 Glenn Randers-Pehrson * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) * @@ -598,11 +598,21 @@ if (png_ptr == NULL) return (NULL); + if (ptime->year > 9999 /* RFC1123 limitation */ || + ptime->month == 0 || ptime->month > 12 || + ptime->day == 0 || ptime->day > 31 || + ptime->hour > 23 || ptime->minute > 59 || + ptime->second > 60) + { + png_warning(png_ptr, "Ignoring invalid time value"); + return (NULL); + } + { size_t pos = 0; - char number_buf[5]; /* enough for a four digit year */ + char number_buf[5]; /* enough for a four-digit year */ # define APPEND_STRING(string)\ pos = png_safecat(png_ptr->time_buffer, sizeof png_ptr->time_buffer,\ pos, (string)) @@ -611,19 +621,19 @@ # define APPEND(ch)\ if (pos < (sizeof png_ptr->time_buffer)-1)\ png_ptr->time_buffer[pos++] = (ch) - APPEND_NUMBER(PNG_NUMBER_FORMAT_u, (unsigned)ptime->day % 32); + APPEND_NUMBER(PNG_NUMBER_FORMAT_u, (unsigned)ptime->day); APPEND(' '); - APPEND_STRING(short_months[(ptime->month - 1) % 12]); + APPEND_STRING(short_months[(ptime->month - 1)]); APPEND(' '); APPEND_NUMBER(PNG_NUMBER_FORMAT_u, ptime->year); APPEND(' '); - APPEND_NUMBER(PNG_NUMBER_FORMAT_02u, (unsigned)ptime->hour % 24); + APPEND_NUMBER(PNG_NUMBER_FORMAT_02u, (unsigned)ptime->hour); APPEND(':'); - APPEND_NUMBER(PNG_NUMBER_FORMAT_02u, (unsigned)ptime->minute % 60); + APPEND_NUMBER(PNG_NUMBER_FORMAT_02u, (unsigned)ptime->minute); APPEND(':'); - APPEND_NUMBER(PNG_NUMBER_FORMAT_02u, (unsigned)ptime->second % 61); + APPEND_NUMBER(PNG_NUMBER_FORMAT_02u, (unsigned)ptime->second); APPEND_STRING(" +0000"); /* This reliably terminates the buffer */ # undef APPEND # undef APPEND_NUMBER @@ -2163,11 +2173,11 @@ */ static png_uint_32 png_8bit_l2[128] = { -# if PNG_DO_BC +# ifdef PNG_DO_BC for (i=128;i<256;++i) { .5 - l(i/255)/l(2)*65536*65536; } -# endif +# else 4270715492U, 4222494797U, 4174646467U, 4127164793U, 4080044201U, 4033279239U, 3986864580U, 3940795015U, 3895065449U, 3849670902U, 3804606499U, 3759867474U, 3715449162U, 3671346997U, 3627556511U, 3584073329U, 3540893168U, 3498011834U, 3455425220U, 3413129301U, 3371120137U, 3329393864U, 3287946700U, 3246774933U, @@ -2188,8 +2198,10 @@ 479792461U, 453592303U, 427502463U, 401522014U, 375650043U, 349885648U, 324227938U, 298676034U, 273229066U, 247886176U, 222646516U, 197509248U, 172473545U, 147538590U, 122703574U, 97967701U, 73330182U, 48790236U, 24347096U, 0U +# endif + #if 0 /* The following are the values for 16-bit tables - these work fine for the * 8-bit conversions but produce very slightly larger errors in the 16-bit * log (about 1.2 as opposed to 0.7 absolute error in the final value). To @@ -2322,9 +2334,9 @@ * each case only the low 16 bits are relevant - the fraction - since the * integer bits (the top 4) simply determine a shift. * * The worst case is the 16-bit distinction between 65535 and 65534, this - * requires perhaps spurious accuracty in the decoding of the logarithm to + * requires perhaps spurious accuracy in the decoding of the logarithm to * distinguish log2(65535/65534.5) - 10^-5 or 17 bits. There is little chance * of getting this accuracy in practice. * * To deal with this the following exp() function works out the exponent of the @@ -2333,19 +2345,20 @@ */ static png_uint_32 png_32bit_exp[16] = { -# if PNG_DO_BC +# ifdef PNG_DO_BC for (i=0;i<16;++i) { .5 + e(-i/16*l(2))*2^32; } -# endif +# else /* NOTE: the first entry is deliberately set to the maximum 32-bit value. */ 4294967295U, 4112874773U, 3938502376U, 3771522796U, 3611622603U, 3458501653U, 3311872529U, 3171459999U, 3037000500U, 2908241642U, 2784941738U, 2666869345U, 2553802834U, 2445529972U, 2341847524U, 2242560872U +# endif }; /* Adjustment table; provided to explain the numbers in the code below. */ -#if PNG_DO_BC +#ifdef PNG_DO_BC for (i=11;i>=0;--i){ print i, " ", (1 - e(-(2^i)/65536*l(2))) * 2^(32-i), "\n"} 11 44937.64284865548751208448 10 45180.98734845585101160448 9 45303.31936980687359311872 @@ -2506,9 +2519,9 @@ gamma_val > PNG_FP_1 + PNG_GAMMA_THRESHOLD_FIXED; } /* Internal function to build a single 16-bit table - the table consists of - * 'num' 256 entry subtables, where 'num' is determined by 'shift' - the amount + * 'num' 256-entry subtables, where 'num' is determined by 'shift' - the amount * to shift the input values right (or 16-number_of_signifiant_bits). * * The caller is responsible for ensuring that the table gets cleaned up on * png_error (i.e. if one of the mallocs below fails) - i.e. the *table argument @@ -2593,11 +2606,11 @@ png_uint_16pp table = *ptable = (png_uint_16pp)png_calloc(png_ptr, num * png_sizeof(png_uint_16p)); - /* 'num' is the number of tables and also the number of low bits of low - * bits of the input 16-bit value used to select a table. Each table is - * itself index by the high 8 bits of the value. + /* 'num' is the number of tables and also the number of low bits of the + * input 16-bit value used to select a table. Each table is itself indexed + * by the high 8 bits of the value. */ for (i = 0; i < num; i++) table[i] = (png_uint_16p)png_malloc(png_ptr, 256 * png_sizeof(png_uint_16)); @@ -2646,9 +2659,9 @@ } /* Build a single 8-bit table: same as the 16-bit case but much simpler (and * typically much faster). Note that libpng currently does no sBIT processing - * (apparently contrary to the spec) so a 256 entry table is always generated. + * (apparently contrary to the spec) so a 256-entry table is always generated. */ static void png_build_8bit_table(png_structp png_ptr, png_bytepp ptable, PNG_CONST png_fixed_point gamma_val) @@ -2782,9 +2795,9 @@ * * Where 'iv' is the input color value and 'ov' is the output value - * pow(iv, gamma). * - * Thus the gamma table consists of up to 256 256 entry tables. The table + * Thus the gamma table consists of up to 256 256-entry tables. The table * is selected by the (8-gamma_shift) most significant of the low 8 bits of * the color value then indexed by the upper 8 bits: * * table[low bits][high 8 bits] diff -ru4NwbB libpng-1.5.6/png.h libpng-1.5.7rc01/png.h --- libpng-1.5.6/png.h 2011-11-02 22:42:50.344556602 -0500 +++ libpng-1.5.7rc01/png.h 2011-12-01 09:01:18.216887077 -0600 @@ -162,8 +162,10 @@ * 1.5.5 15 10505 15.so.15.5[.0] * 1.5.6beta01-07 15 10506 15.so.15.6[.0] * 1.5.6rc01-03 15 10506 15.so.15.6[.0] * 1.5.6 15 10506 15.so.15.6[.0] + * 1.5.7beta01-05 15 10507 15.so.15.7[.0] + * 1.5.7rc01 15 10507 15.so.15.7[.0] * * Henceforth the source version will match the shared-library major * and minor numbers; the shared-library major version number will be * used for changes in backward compatibility, as it is intended. The @@ -363,8 +365,11 @@ /* This is not the place to learn how to use libpng. The file libpng-manual.txt * describes how to use libpng, and the file example.c summarizes it * with some code on which to build. This file is useful for looking * at the actual function definitions and structure components. + * + * If you just need to read a PNG file and don't want to read the documentation + * skip to the end of this file and read the section entitled 'simplified API'. */ /* Version information for png.h - this should match the version in png.c */ #define PNG_LIBPNG_VER_STRING "1.5.7rc01" @@ -603,13 +609,22 @@ #ifdef PNG_TEXT_SUPPORTED /* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file, * and whether that contents is compressed or not. The "key" field - * points to a regular zero-terminated C string. The "text", "lang", and - * "lang_key" fields can be regular C strings, empty strings, or NULL pointers. + * points to a regular zero-terminated C string. The "text" fields can be a + * regular C string, an empty string, or a NULL pointer. * However, the structure returned by png_get_text() will always contain - * regular zero-terminated C strings (possibly empty), never NULL pointers, - * so they can be safely used in printf() and other string-handling functions. + * the "text" field as a regular zero-terminated C string (possibly + * empty), never a NULL pointer, so it can be safely used in printf() and + * other string-handling functions. Note that the "itxt_length", "lang", and + * "lang_key" members of the structure only exist when the library is built + * with iTXt chunk support. Prior to libpng-1.4.0 the library was built by + * default without iTXt support. Also note that when iTXt *is* supported, + * the "lang" and "lang_key" fields contain NULL pointers when the + * "compression" field contains * PNG_TEXT_COMPRESSION_NONE or + * PNG_TEXT_COMPRESSION_zTXt. Note that the "compression value" is not the + * same as what appears in the PNG tEXt/zTXt/iTXt chunk's "compression flag" + * which is always 0 or 1, or its "compression method" which is always 0. */ typedef struct png_text_struct { int compression; /* compression value: @@ -1122,8 +1137,13 @@ #endif #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED /* Reduce RGB to grayscale. */ +#define PNG_ERROR_ACTION_NONE 1 +#define PNG_ERROR_ACTION_WARN 2 +#define PNG_ERROR_ACTION_ERROR 3 +#define PNG_RGB_TO_GRAY_DEFAULT (-1)/*for red/green coefficients*/ + PNG_FP_EXPORT(32, void, png_set_rgb_to_gray, (png_structp png_ptr, int error_action, double red, double green)); PNG_FIXED_EXPORT(33, void, png_set_rgb_to_gray_fixed, (png_structp png_ptr, int error_action, png_fixed_point red, png_fixed_point green)); diff -ru4NwbB libpng-1.5.6/pngerror.c libpng-1.5.7rc01/pngerror.c --- libpng-1.5.6/pngerror.c 2011-11-02 22:42:50.406539999 -0500 +++ libpng-1.5.7rc01/pngerror.c 2011-12-01 09:01:18.280185175 -0600 @@ -1,8 +1,8 @@ /* pngerror.c - stub functions for i/o and memory allocation * - * Last changed in libpng 1.5.6 [(PENDING RELEASE)] + * Last changed in libpng 1.5.7 [(PENDING RELEASE)] * Copyright (c) 1998-2011 Glenn Randers-Pehrson * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) * diff -ru4NwbB libpng-1.5.6/pngget.c libpng-1.5.7rc01/pngget.c --- libpng-1.5.6/pngget.c 2011-11-02 22:42:50.414779399 -0500 +++ libpng-1.5.7rc01/pngget.c 2011-12-01 09:01:18.288344678 -0600 @@ -1,8 +1,8 @@ /* pngget.c - retrieval of values from info struct * - * Last changed in libpng 1.5.6 [(PENDING RELEASE)] + * Last changed in libpng 1.5.7 [(PENDING RELEASE)] * Copyright (c) 1998-2011 Glenn Randers-Pehrson * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) * @@ -681,17 +681,18 @@ { png_debug1(1, "in %s retrieval function", "iCCP"); if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_iCCP) - && name != NULL && profile != NULL && proflen != NULL) + && name != NULL && compression_type != NULL && profile != NULL && + proflen != NULL) { *name = info_ptr->iccp_name; *profile = info_ptr->iccp_profile; /* Compression_type is a dummy so the API won't have to change * if we introduce multiple compression types later. */ - *proflen = (int)info_ptr->iccp_proflen; - *compression_type = (int)info_ptr->iccp_compression; + *proflen = info_ptr->iccp_proflen; + *compression_type = info_ptr->iccp_compression; return (PNG_INFO_iCCP); } return (0); diff -ru4NwbB libpng-1.5.6/pngmem.c libpng-1.5.7rc01/pngmem.c --- libpng-1.5.6/pngmem.c 2011-11-02 22:42:50.421685471 -0500 +++ libpng-1.5.7rc01/pngmem.c 2011-12-01 09:01:18.295407323 -0600 @@ -1,8 +1,8 @@ /* pngmem.c - stub functions for memory allocation * - * Last changed in libpng 1.5.4 [July 7, 2011] + * Last changed in libpng 1.5.7 [(PENDING RELEASE)] * Copyright (c) 1998-2011 Glenn Randers-Pehrson * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) * @@ -55,11 +55,11 @@ # ifdef PNG_USER_MEM_SUPPORTED if (malloc_fn != NULL) { png_struct dummy_struct; - png_structp png_ptr = &dummy_struct; - png_ptr->mem_ptr=mem_ptr; - struct_ptr = (*(malloc_fn))(png_ptr, (png_uint_32)size); + memset(&dummy_struct, 0, sizeof dummy_struct); + dummy_struct.mem_ptr=mem_ptr; + struct_ptr = (*(malloc_fn))(&dummy_struct, (png_alloc_size_t)size); } else # endif /* PNG_USER_MEM_SUPPORTED */ @@ -89,11 +89,11 @@ # ifdef PNG_USER_MEM_SUPPORTED if (free_fn != NULL) { png_struct dummy_struct; - png_structp png_ptr = &dummy_struct; - png_ptr->mem_ptr=mem_ptr; - (*(free_fn))(png_ptr, struct_ptr); + memset(&dummy_struct, 0, sizeof dummy_struct); + dummy_struct.mem_ptr=mem_ptr; + (*(free_fn))(&dummy_struct, struct_ptr); return; } # endif /* PNG_USER_MEM_SUPPORTED */ @@ -142,9 +142,9 @@ return (NULL); # ifdef PNG_USER_MEM_SUPPORTED if (png_ptr->malloc_fn != NULL) - ret = ((png_voidp)(*(png_ptr->malloc_fn))(png_ptr, (png_size_t)size)); + ret = ((png_voidp)(*(png_ptr->malloc_fn))(png_ptr, size)); else ret = (png_malloc_default(png_ptr, size)); diff -ru4NwbB libpng-1.5.6/pngpread.c libpng-1.5.7rc01/pngpread.c --- libpng-1.5.6/pngpread.c 2011-11-02 22:42:50.431199446 -0500 +++ libpng-1.5.7rc01/pngpread.c 2011-12-01 09:01:18.304924095 -0600 @@ -1,8 +1,8 @@ /* pngpread.c - read a png file in push mode * - * Last changed in libpng 1.5.6 [(PENDING RELEASE)] + * Last changed in libpng 1.5.7 [(PENDING RELEASE)] * Copyright (c) 1998-2011 Glenn Randers-Pehrson * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) * @@ -984,9 +984,9 @@ if (png_ptr->row_buf[0] > PNG_FILTER_VALUE_NONE) { if (png_ptr->row_buf[0] < PNG_FILTER_VALUE_LAST) - png_read_filter_row(&row_info, png_ptr->row_buf + 1, + png_read_filter_row(png_ptr, &row_info, png_ptr->row_buf + 1, png_ptr->prev_row + 1, png_ptr->row_buf[0]); else png_error(png_ptr, "bad adaptive filter value"); } diff -ru4NwbB libpng-1.5.6/pngpriv.h libpng-1.5.7rc01/pngpriv.h --- libpng-1.5.6/pngpriv.h 2011-11-02 22:42:50.361693834 -0500 +++ libpng-1.5.7rc01/pngpriv.h 2011-12-01 09:01:18.234792360 -0600 @@ -5,9 +5,9 @@ * Copyright (c) 1998-2011 Glenn Randers-Pehrson * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) * - * Last changed in libpng 1.5.6 [(PENDING RELEASE)] + * Last changed in libpng 1.5.7 [(PENDING RELEASE)] * * This code is released under the libpng license. * For conditions of distribution and use, see the disclaimer * and license in png.h @@ -195,8 +195,25 @@ #ifndef PNG_STATIC # define PNG_STATIC static #endif +/* C99 restrict is used where possible, to do this 'restrict' is defined as + * empty if we can't be sure it is supported. configure builds have already + * done this work. + */ +#ifdef PNG_CONFIGURE_LIBPNG +# define PNG_RESTRICT restrict +#else + /* Modern compilers support restrict, but assume not for anything not + * recognized here: + */ +# if defined __GNUC__ || defined _MSC_VER || defined __WATCOMC__ +# define PNG_RESTRICT restrict +# else +# define PNG_RESTRICT +# endif +#endif + /* If warnings or errors are turned off the code is disabled or redirected here. * From 1.5.4 functions have been added to allow very limited formatting of * error and warning messages - this code will also be disabled here. */ @@ -216,17 +233,30 @@ # define png_chunk_error(s1,s2) png_err(s1) # define png_fixed_error(s1,s2) png_err(s1) #endif +/* C allows up-casts from (void*) to any pointer and (const void*) to any + * pointer to a const object. C++ regards this as a type error and requires an + * explicit, static, cast and provides the static_cast<> rune to ensure that + * const is not cast away. + */ +#ifdef __cplusplus +# define png_voidcast(type, value) static_cast(value) +#else +# define png_voidcast(type, value) (value) +#endif /* __cplusplus */ + #ifndef PNG_EXTERN /* The functions exported by PNG_EXTERN are internal functions, which * aren't usually used outside the library (as far as I know), so it is * debatable if they should be exported at all. In the future, when it * is possible to have run-time registry of chunk-handling functions, * some of these might be made available again. -# define PNG_EXTERN extern + * + * 1.5.7: turned the use of 'extern' back on, since it is localized to pngpriv.h + * it should be safe now (it is unclear why it was turned off.) */ -# define PNG_EXTERN +# define PNG_EXTERN extern #endif /* Some fixed point APIs are still required even if not exported because * they get used by the corresponding floating point APIs. This magic @@ -921,11 +951,26 @@ /* Unfilter a row: check the filter value before calling this, there is no point * calling it for PNG_FILTER_VALUE_NONE. */ -PNG_EXTERN void png_read_filter_row PNGARG((png_row_infop row_info, +PNG_EXTERN void png_read_filter_row PNGARG((png_structp pp, png_row_infop row_info, png_bytep row, png_const_bytep prev_row, int filter)); +PNG_EXTERN void png_read_filter_row_up_neon PNGARG((png_row_infop row_info, + png_bytep row, png_const_bytep prev_row)); +PNG_EXTERN void png_read_filter_row_sub3_neon PNGARG((png_row_infop row_info, + png_bytep row, png_const_bytep prev_row)); +PNG_EXTERN void png_read_filter_row_sub4_neon PNGARG((png_row_infop row_info, + png_bytep row, png_const_bytep prev_row)); +PNG_EXTERN void png_read_filter_row_avg3_neon PNGARG((png_row_infop row_info, + png_bytep row, png_const_bytep prev_row)); +PNG_EXTERN void png_read_filter_row_avg4_neon PNGARG((png_row_infop row_info, + png_bytep row, png_const_bytep prev_row)); +PNG_EXTERN void png_read_filter_row_paeth3_neon PNGARG((png_row_infop row_info, + png_bytep row, png_const_bytep prev_row)); +PNG_EXTERN void png_read_filter_row_paeth4_neon PNGARG((png_row_infop row_info, + png_bytep row, png_const_bytep prev_row)); + /* Choose the best filter to use and filter the row data */ PNG_EXTERN void png_write_find_filter PNGARG((png_structp png_ptr, png_row_infop row_info)); diff -ru4NwbB libpng-1.5.6/pngread.c libpng-1.5.7rc01/pngread.c --- libpng-1.5.6/pngread.c 2011-11-02 22:42:50.439731962 -0500 +++ libpng-1.5.7rc01/pngread.c 2011-12-01 09:01:18.313421043 -0600 @@ -1,8 +1,8 @@ /* pngread.c - read a PNG file * - * Last changed in libpng 1.5.6 [(PENDING RELEASE)] + * Last changed in libpng 1.5.7 [(PENDING RELEASE)] * Copyright (c) 1998-2011 Glenn Randers-Pehrson * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) * @@ -79,10 +79,11 @@ #endif #ifdef PNG_SETJMP_SUPPORTED /* Applications that neglect to set up their own setjmp() and then - encounter a png_error() will longjmp here. Since the jmpbuf is - then meaningless we abort instead of returning. */ + * encounter a png_error() will longjmp here. Since the jmpbuf is + * then meaningless we abort instead of returning. + */ #ifdef USE_FAR_KEYWORD if (setjmp(tmp_jmpbuf)) #else if (setjmp(png_jmpbuf(png_ptr))) /* Sets longjmp to match setjmp */ @@ -577,9 +578,9 @@ if (png_ptr->row_buf[0] > PNG_FILTER_VALUE_NONE) { if (png_ptr->row_buf[0] < PNG_FILTER_VALUE_LAST) - png_read_filter_row(&row_info, png_ptr->row_buf + 1, + png_read_filter_row(png_ptr, &row_info, png_ptr->row_buf + 1, png_ptr->prev_row + 1, png_ptr->row_buf[0]); else png_error(png_ptr, "bad adaptive filter value"); } diff -ru4NwbB libpng-1.5.6/pngrtran.c libpng-1.5.7rc01/pngrtran.c --- libpng-1.5.6/pngrtran.c 2011-11-02 22:42:50.462840407 -0500 +++ libpng-1.5.7rc01/pngrtran.c 2011-12-01 09:01:18.336457828 -0600 @@ -1,8 +1,8 @@ /* pngrtran.c - transforms the data in a row for PNG readers * - * Last changed in libpng 1.5.6 [(PENDING RELEASE)] + * Last changed in libpng 1.5.7 [(PENDING RELEASE)] * Copyright (c) 1998-2011 Glenn Randers-Pehrson * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) * @@ -935,17 +935,17 @@ return; switch(error_action) { - case 1: + case PNG_ERROR_ACTION_NONE: png_ptr->transformations |= PNG_RGB_TO_GRAY; break; - case 2: + case PNG_ERROR_ACTION_WARN: png_ptr->transformations |= PNG_RGB_TO_GRAY_WARN; break; - case 3: + case PNG_ERROR_ACTION_ERROR: png_ptr->transformations |= PNG_RGB_TO_GRAY_ERR; break; default: @@ -1464,8 +1464,30 @@ # undef CHOP } #endif /* PNG_READ_BACKGROUND_SUPPORTED && PNG_READ_EXPAND_16_SUPPORTED */ +#if defined(PNG_READ_BACKGROUND_SUPPORTED) && \ + (defined(PNG_READ_SCALE_16_TO_8_SUPPORTED) || \ + defined(PNG_READ_STRIP_16_TO_8_SUPPORTED)) + if ((png_ptr->transformations & (PNG_16_TO_8|PNG_SCALE_16_TO_8)) && + (png_ptr->transformations & PNG_COMPOSE) && + !(png_ptr->transformations & PNG_BACKGROUND_EXPAND) && + png_ptr->bit_depth == 16) + { + /* On the other hand, if a 16-bit file is to be reduced to 8-bits per + * component this will also happen after PNG_COMPOSE and so the background + * color must be pre-expanded here. + * + * TODO: fix this too. + */ + png_ptr->background.red = (png_uint_16)(png_ptr->background.red * 257); + png_ptr->background.green = + (png_uint_16)(png_ptr->background.green * 257); + png_ptr->background.blue = (png_uint_16)(png_ptr->background.blue * 257); + png_ptr->background.gray = (png_uint_16)(png_ptr->background.gray * 257); + } +#endif + /* NOTE: below 'PNG_READ_ALPHA_MODE_SUPPORTED' is presumed to also enable the * background support (see the comments in scripts/pnglibconf.dfa), this * allows pre-multiplication of the alpha channel to be implemented as * compositing on black. This is probably sub-optimal and has been done in @@ -1511,8 +1533,18 @@ #ifdef PNG_READ_BACKGROUND_SUPPORTED if (png_ptr->transformations & PNG_COMPOSE) { + /* Issue a warning about this combination: because RGB_TO_GRAY is + * optimized to do the gamma transform if present yet do_background has + * to do the same thing if both options are set a + * double-gamma-correction happens. This is true in all versions of + * libpng to date. + */ + if (png_ptr->transformations & PNG_RGB_TO_GRAY) + png_warning(png_ptr, + "libpng does not support gamma+background+rgb_to_gray"); + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) { /* We don't get to here unless there is a tRNS chunk with non-opaque * entries - see the checking code at the start of this function. @@ -1725,9 +1757,15 @@ else /* Transformation does not include PNG_BACKGROUND */ #endif /* PNG_READ_BACKGROUND_SUPPORTED */ - if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED + /* RGB_TO_GRAY needs to have non-gamma-corrected values! */ + && ((png_ptr->transformations & PNG_EXPAND) == 0 || + (png_ptr->transformations & PNG_RGB_TO_GRAY) == 0) +#endif + ) { png_colorp palette = png_ptr->palette; int num_palette = png_ptr->num_palette; int i; @@ -1917,9 +1955,9 @@ png_ptr->transformations |= PNG_16_TO_8; info_ptr->bit_depth = 8; # else -# if PNG_READ_SCALE_16_TO_8_SUPPORTED +# ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED png_ptr->transformations |= PNG_SCALE_16_TO_8; info_ptr->bit_depth = 8; # else @@ -2164,14 +2202,24 @@ #endif #ifdef PNG_READ_GAMMA_SUPPORTED if ((png_ptr->transformations & PNG_GAMMA) && +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED + /* Because RGB_TO_GRAY does the gamma transform. */ + !(png_ptr->transformations & PNG_RGB_TO_GRAY) && +#endif #if (defined PNG_READ_BACKGROUND_SUPPORTED) ||\ (defined PNG_READ_ALPHA_MODE_SUPPORTED) + /* Because PNG_COMPOSE does the gamma transform if there is something to + * do (if there is an alpha channel or transparency.) + */ !((png_ptr->transformations & PNG_COMPOSE) && ((png_ptr->num_trans != 0) || (png_ptr->color_type & PNG_COLOR_MASK_ALPHA))) && #endif + /* Because png_init_read_transformations transforms the palette, unless + * RGB_TO_GRAY will do the transform. + */ (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE)) png_do_gamma(row_info, png_ptr->row_buf + 1, png_ptr); #endif @@ -2561,9 +2609,9 @@ if (row_info->bit_depth == 16) { png_bytep sp = row; /* source */ - png_bytep dp = row; /* destinaton */ + png_bytep dp = row; /* destination */ png_bytep ep = sp + row_info->rowbytes; /* end+1 */ while (sp < ep) { @@ -2622,9 +2670,9 @@ if (row_info->bit_depth == 16) { png_bytep sp = row; /* source */ - png_bytep dp = row; /* destinaton */ + png_bytep dp = row; /* destination */ png_bytep ep = sp + row_info->rowbytes; /* end+1 */ while (sp < ep) { @@ -3330,9 +3378,9 @@ if (red != green || red != blue) rgb_error |= 1; - /* From 1.5.5 in the 16 bit case do the accurate convertion even + /* From 1.5.5 in the 16 bit case do the accurate conversion even * in the 'fast' case - this is because this is where the code * ends up when handling linear 16 bit data. */ gray16 = (png_uint_16)((rc*red + gc*green + bc*blue + 16384) >> diff -ru4NwbB libpng-1.5.6/pngrutil.c libpng-1.5.7rc01/pngrutil.c --- libpng-1.5.6/pngrutil.c 2011-11-02 22:42:50.478366695 -0500 +++ libpng-1.5.7rc01/pngrutil.c 2011-12-01 09:01:18.352148324 -0600 @@ -1,8 +1,8 @@ /* pngrutil.c - utilities to read a PNG file * - * Last changed in libpng 1.5.6 [(PENDING RELEASE)] + * Last changed in libpng 1.5.7 [(PENDING RELEASE)] * Copyright (c) 1998-2011 Glenn Randers-Pehrson * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) * @@ -489,9 +489,9 @@ else /* if (comp_type != PNG_COMPRESSION_TYPE_BASE) */ { PNG_WARNING_PARAMETERS(p) png_warning_parameter_signed(p, 1, PNG_NUMBER_FORMAT_d, comp_type); - png_formatted_warning(png_ptr, p, "Unknown zTXt compression type @1"); + png_formatted_warning(png_ptr, p, "Unknown compression type @1"); /* The recovery is to simply drop the data. */ } @@ -2539,8 +2539,16 @@ comp_flag = *lang++; comp_type = *lang++; } + if (comp_type || (comp_flag && comp_flag != PNG_TEXT_COMPRESSION_zTXt)) + { + png_warning(png_ptr, "Unknown iTXt compression type or method"); + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + return; + } + for (lang_key = lang; *lang_key; lang_key++) /* Empty loop */ ; lang_key++; /* Skip NUL separator */ @@ -2766,20 +2774,15 @@ chunk_name >>= 8; } } -/* Combines the row recently read in with the existing pixels in the - * row. This routine takes care of alpha and transparency if requested. - * This routine also handles the two methods of progressive display - * of interlaced images, depending on the mask value. - * The mask value describes which pixels are to be combined with - * the row. The pattern always repeats every 8 pixels, so just 8 - * bits are needed. A one indicates the pixel is to be combined, - * a zero indicates the pixel is to be skipped. This is in addition - * to any alpha or transparency value associated with the pixel. If - * you want all pixels to be combined, pass 0xff (255) in mask. +/* Combines the row recently read in with the existing pixels in the row. This + * routine takes care of alpha and transparency if requested. This routine also + * handles the two methods of progressive display of interlaced images, + * depending on the 'display' value; if 'display' is true then the whole row + * (dp) is filled from the start by replicating the available pixels. If + * 'display' is false only those pixels present in the pass are filled in. */ - void /* PRIVATE */ png_combine_row(png_structp png_ptr, png_bytep dp, int display) { unsigned int pixel_depth = png_ptr->transformed_pixel_depth; @@ -2849,26 +2852,26 @@ return; if (pixel_depth < 8) { - /* For pixel depths up to 4-bpp the 8-pixel mask can be expanded to fit + /* For pixel depths up to 4 bpp the 8-pixel mask can be expanded to fit * into 32 bits, then a single loop over the bytes using the four byte * values in the 32-bit mask can be used. For the 'display' option the * expanded mask may also not require any masking within a byte. To * make this work the PACKSWAP option must be taken into account - it * simply requires the pixels to be reversed in each byte. * * The 'regular' case requires a mask for each of the first 6 passes, * the 'display' case does a copy for the even passes in the range - * 0..6. This has already been handled in the tst above. + * 0..6. This has already been handled in the test above. * * The masks are arranged as four bytes with the first byte to use in * the lowest bits (little-endian) regardless of the order (PACKSWAP or * not) of the pixels in each byte. * * NOTE: the whole of this logic depends on the caller of this function * only calling it on rows appropriate to the pass. This function only - * understands the 'x' logic, the 'y' logic is handled by the caller. + * understands the 'x' logic; the 'y' logic is handled by the caller. * * The following defines allow generation of compile time constant bit * masks for each pixel depth and each possibility of swapped or not * swapped bytes. Pass 'p' is in the range 0..6; 'x', a pixel index, @@ -2884,9 +2887,9 @@ * because the right hand side of the ?: expression is evaluated by * the compiler even though it isn't used. Microsoft Visual C (various * versions) and the Intel C compiler are known to do this. To avoid * this the following macros are used in 1.5.6. This is a temporary - * solution to avoid destablizing the code during the release process. + * solution to avoid destabilizing the code during the release process. */ # if PNG_USE_COMPILE_TIME_MASKS # define PNG_LSR(x,s) ((x)>>((s) & 0x1f)) # define PNG_LSL(x,s) ((x)<<((s) & 0x1f)) @@ -2929,9 +2932,9 @@ #if PNG_USE_COMPILE_TIME_MASKS /* Utility macros to construct all the masks for a depth/swap * combination. The 's' parameter says whether the format is PNG - * (big endian bytes) or not. Only the three odd numbered passes are + * (big endian bytes) or not. Only the three odd-numbered passes are * required for the display/block algorithm. */ # define S_MASKS(d,s) { S_MASK(0,d,s), S_MASK(1,d,s), S_MASK(2,d,s),\ S_MASK(3,d,s), S_MASK(4,d,s), S_MASK(5,d,s) } @@ -2942,9 +2945,10 @@ /* Hence the pre-compiled masks indexed by PACKSWAP (or not), depth and * then pass: */ - static PNG_CONST png_uint_32 row_mask[2/*PACKSWAP*/][3/*depth*/][6] = { + static PNG_CONST png_uint_32 row_mask[2/*PACKSWAP*/][3/*depth*/][6] = + { /* Little-endian byte masks for PACKSWAP */ { S_MASKS(1,0), S_MASKS(2,0), S_MASKS(4,0) }, /* Normal (big-endian byte) masks - PNG format */ { S_MASKS(1,1), S_MASKS(2,1), S_MASKS(4,1) } @@ -2952,9 +2956,10 @@ /* display_mask has only three entries for the odd passes, so index by * pass>>1. */ - static PNG_CONST png_uint_32 display_mask[2][3][3] = { + static PNG_CONST png_uint_32 display_mask[2][3][3] = + { /* Little-endian byte masks for PACKSWAP */ { B_MASKS(1,0), B_MASKS(2,0), B_MASKS(4,0) }, /* Normal (big-endian byte) masks - PNG format */ { B_MASKS(1,1), B_MASKS(2,1), B_MASKS(4,1) } @@ -3128,9 +3133,9 @@ #if PNG_ALIGN_TYPE != PNG_ALIGN_NONE /* Check for double byte alignment and, if possible, use a * 16-bit copy. Don't attempt this for narrow images - ones that * are less than an interlace panel wide. Don't attempt it for - * wide bytes-to-copy either - use the png_memcpy there. + * wide bytes_to_copy either - use the png_memcpy there. */ if (bytes_to_copy < 16 /*else use png_memcpy*/ && png_isaligned(dp, png_uint_16) && png_isaligned(sp, png_uint_16) && @@ -3497,36 +3502,29 @@ #endif } #endif /* PNG_READ_INTERLACING_SUPPORTED */ -/* 1.5.6: Changed to just take a png_row_info (not png_ptr) and to ignore bad - * adaptive filter bytes. - */ -void /* PRIVATE */ -png_read_filter_row(png_row_infop row_info, png_bytep row, - png_const_bytep prev_row, int filter) -{ - switch (filter) - { - case PNG_FILTER_VALUE_NONE: - break; - - case PNG_FILTER_VALUE_SUB: +static void +png_read_filter_row_sub(png_row_infop row_info, png_bytep row, + png_const_bytep prev_row) { png_size_t i; png_size_t istop = row_info->rowbytes; unsigned int bpp = (row_info->pixel_depth + 7) >> 3; png_bytep rp = row + bpp; - png_bytep lp = row; + + PNG_UNUSED(prev_row) for (i = bpp; i < istop; i++) { - *rp = (png_byte)(((int)(*rp) + (int)(*lp++)) & 0xff); + *rp = (png_byte)(((int)(*rp) + (int)(*(rp-bpp))) & 0xff); rp++; } - break; } - case PNG_FILTER_VALUE_UP: + +static void +png_read_filter_row_up(png_row_infop row_info, png_bytep row, + png_const_bytep prev_row) { png_size_t i; png_size_t istop = row_info->rowbytes; png_bytep rp = row; @@ -3536,16 +3534,17 @@ { *rp = (png_byte)(((int)(*rp) + (int)(*pp++)) & 0xff); rp++; } - break; } - case PNG_FILTER_VALUE_AVG: + +static void +png_read_filter_row_avg(png_row_infop row_info, png_bytep row, + png_const_bytep prev_row) { png_size_t i; png_bytep rp = row; png_const_bytep pp = prev_row; - png_bytep lp = row; unsigned int bpp = (row_info->pixel_depth + 7) >> 3; png_size_t istop = row_info->rowbytes - bpp; for (i = 0; i < bpp; i++) @@ -3558,37 +3557,88 @@ for (i = 0; i < istop; i++) { *rp = (png_byte)(((int)(*rp) + - (int)(*pp++ + *lp++) / 2 ) & 0xff); + (int)(*pp++ + *(rp-bpp)) / 2 ) & 0xff); rp++; } - break; } - case PNG_FILTER_VALUE_PAETH: + +static void +png_read_filter_row_paeth_1byte_pixel(png_row_infop row_info, png_bytep row, + png_const_bytep prev_row) { - png_size_t i; - png_bytep rp = row; - png_const_bytep pp = prev_row; - png_bytep lp = row; - png_const_bytep cp = prev_row; - unsigned int bpp = (row_info->pixel_depth + 7) >> 3; - png_size_t istop=row_info->rowbytes - bpp; + png_bytep rp_end = row + row_info->rowbytes; + int a, c; - for (i = 0; i < bpp; i++) + /* First pixel/byte */ + c = *prev_row++; + a = *row + c; + *row++ = (png_byte)a; + + /* Remainder */ + while (row < rp_end) { - *rp = (png_byte)(((int)(*rp) + (int)(*pp++)) & 0xff); - rp++; + int b, pa, pb, pc, p; + + a &= 0xff; /* From previous iteration or start */ + b = *prev_row++; + + p = b - c; + pc = a - c; + +# ifdef PNG_USE_ABS + pa = abs(p); + pb = abs(pc); + pc = abs(p + pc); +# else + pa = p < 0 ? -p : p; + pb = pc < 0 ? -pc : pc; + pc = (p + pc) < 0 ? -(p + pc) : p + pc; +# endif + + /* Find the best predictor, the least of pa, pb, pc favoring the earlier + * ones in the case of a tie. + */ + if (pb < pa) pa = pb, a = b; + if (pc < pa) a = c; + + /* Calculate the current pixel in a, and move the previous row pixel to c + * for the next time round the loop + */ + c = b; + a += *row; + *row++ = (png_byte)a; + } +} + +static void +png_read_filter_row_paeth_multibyte_pixel(png_row_infop row_info, png_bytep row, + png_const_bytep prev_row) +{ + int bpp = (row_info->pixel_depth + 7) >> 3; + png_bytep rp_end = row + bpp; + + /* Process the first pixel in the row completely (this is the same as 'up' + * because there is only one candidate predictor for the first row). + */ + while (row < rp_end) + { + int a = *row + *prev_row++; + *row++ = (png_byte)a; } - for (i = 0; i < istop; i++) /* Use leftover rp,pp */ + /* Remainder */ + rp_end += row_info->rowbytes - bpp; + + while (row < rp_end) { int a, b, c, pa, pb, pc, p; - a = *lp++; - b = *pp++; - c = *cp++; + c = *(prev_row - bpp); + a = *(row - bpp); + b = *prev_row++; p = b - c; pc = a - c; @@ -3601,30 +3651,105 @@ pb = pc < 0 ? -pc : pc; pc = (p + pc) < 0 ? -(p + pc) : p + pc; #endif - /* - if (pa <= pb && pa <= pc) - p = a; + if (pb < pa) pa = pb, a = b; + if (pc < pa) a = c; + + c = b; + a += *row; + *row++ = (png_byte)a; + } +} - else if (pb <= pc) - p = b; +#ifdef PNG_ARM_NEON - else - p = c; - */ +#ifdef __linux__ +#include +#include +#include - p = (pa <= pb && pa <= pc) ? a : (pb <= pc) ? b : c; +static int png_have_hwcap(unsigned cap) +{ + FILE *f = fopen("/proc/self/auxv", "r"); + Elf32_auxv_t aux; + int have_cap = 0; - *rp = (png_byte)(((int)(*rp) + p) & 0xff); - rp++; - } + if (!f) + return 0; + + while (fread(&aux, sizeof(aux), 1, f) > 0) + { + if (aux.a_type == AT_HWCAP && + aux.a_un.a_val & cap) + { + have_cap = 1; break; } - default: - /* NOT REACHED */ - break; } + + fclose(f); + + return have_cap; +} +#endif /* __linux__ */ + +static void +png_init_filter_functions_neon(png_structp pp, unsigned int bpp) +{ +#ifdef __linux__ + if (!png_have_hwcap(HWCAP_NEON)) + return; +#endif + + pp->read_filter[PNG_FILTER_VALUE_UP-1] = png_read_filter_row_up_neon; + + if (bpp == 3) + { + pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub3_neon; + pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg3_neon; + pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = + png_read_filter_row_paeth3_neon; + } + + else if (bpp == 4) + { + pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub4_neon; + pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg4_neon; + pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = + png_read_filter_row_paeth4_neon; + } +} +#endif /* PNG_ARM_NEON */ + +static void +png_init_filter_functions(png_structp pp) +{ + unsigned int bpp = (pp->pixel_depth + 7) >> 3; + + pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub; + pp->read_filter[PNG_FILTER_VALUE_UP-1] = png_read_filter_row_up; + pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg; + if (bpp == 1) + pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = + png_read_filter_row_paeth_1byte_pixel; + else + pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = + png_read_filter_row_paeth_multibyte_pixel; + +#ifdef PNG_ARM_NEON + png_init_filter_functions_neon(pp, bpp); +#endif +} + +void /* PRIVATE */ +png_read_filter_row(png_structp pp, png_row_infop row_info, png_bytep row, + png_const_bytep prev_row, int filter) +{ + if (pp->read_filter[0] == NULL) + png_init_filter_functions(pp); + if (filter > PNG_FILTER_VALUE_NONE && filter < PNG_FILTER_VALUE_LAST) + pp->read_filter[filter-1](row_info, row, prev_row); } #ifdef PNG_SEQUENTIAL_READ_SUPPORTED void /* PRIVATE */ @@ -3810,8 +3935,18 @@ } max_pixel_depth = png_ptr->pixel_depth; + /* WARNING: * png_read_transform_info (pngrtran.c) performs a simpliar set of + * calculations to calculate the final pixel depth, then + * png_do_read_transforms actually does the transforms. This means that the + * code which effectively calculates this value is actually repeated in three + * separate places. They must all match. Innocent changes to the order of + * transformations can and will break libpng in a way that causes memory + * overwrites. + * + * TODO: fix this. + */ #ifdef PNG_READ_PACK_SUPPORTED if ((png_ptr->transformations & PNG_PACK) && png_ptr->bit_depth < 8) max_pixel_depth = 8; #endif @@ -3868,21 +4003,19 @@ #ifdef PNG_READ_FILLER_SUPPORTED if (png_ptr->transformations & (PNG_FILLER)) { - if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) - max_pixel_depth = 32; - - else if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY) + if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY) { if (max_pixel_depth <= 8) max_pixel_depth = 16; else max_pixel_depth = 32; } - else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB) + else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB || + png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) { if (max_pixel_depth <= 32) max_pixel_depth = 32; diff -ru4NwbB libpng-1.5.6/pngset.c libpng-1.5.7rc01/pngset.c --- libpng-1.5.6/pngset.c 2011-11-02 22:42:50.486944000 -0500 +++ libpng-1.5.7rc01/pngset.c 2011-12-01 09:01:18.360718018 -0600 @@ -1,8 +1,8 @@ /* pngset.c - storage of image information into info struct * - * Last changed in libpng 1.5.6 [(PENDING RELEASE)] + * Last changed in libpng 1.5.6 [November 3, 2011] * Copyright (c) 1998-2011 Glenn Randers-Pehrson * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) * @@ -863,8 +863,17 @@ if (png_ptr == NULL || info_ptr == NULL || (png_ptr->mode & PNG_WROTE_tIME)) return; + if (mod_time->month == 0 || mod_time->month > 12 || + mod_time->day == 0 || mod_time->day > 31 || + mod_time->hour > 23 || mod_time->minute > 59 || + mod_time->second > 60) + { + png_warning(png_ptr, "Ignoring invalid time value"); + return; + } + png_memcpy(&(info_ptr->mod_time), mod_time, png_sizeof(png_time)); info_ptr->valid |= PNG_INFO_tIME; } #endif diff -ru4NwbB libpng-1.5.6/pngstruct.h libpng-1.5.7rc01/pngstruct.h --- libpng-1.5.6/pngstruct.h 2011-11-02 22:42:50.368044918 -0500 +++ libpng-1.5.7rc01/pngstruct.h 2011-12-01 09:01:18.241448992 -0600 @@ -352,6 +352,9 @@ #endif /* New member added in libpng-1.5.6 */ png_bytep big_prev_row; + + void (*read_filter[PNG_FILTER_VALUE_LAST-1])(png_row_infop row_info, + png_bytep row, png_const_bytep prev_row); }; #endif /* PNGSTRUCT_H */ diff -ru4NwbB libpng-1.5.6/pngtest.c libpng-1.5.7rc01/pngtest.c --- libpng-1.5.6/pngtest.c 2011-11-02 22:42:50.496589188 -0500 +++ libpng-1.5.7rc01/pngtest.c 2011-12-01 09:01:18.370817573 -0600 @@ -1,8 +1,8 @@ /* pngtest.c - a simple test program to test libpng * - * Last changed in libpng 1.5.6 [(PENDING RELEASE)] + * Last changed in libpng 1.5.6 [November 3, 2011] * Copyright (c) 1998-2011 Glenn Randers-Pehrson * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) * @@ -1162,8 +1162,12 @@ if (png_get_text(read_ptr, read_info_ptr, &text_ptr, &num_text) > 0) { pngtest_debug1("Handling %d iTXt/tEXt/zTXt chunks", num_text); + + if (verbose) + printf("\nText compression=%d\n", text_ptr->compression); + png_set_text(write_ptr, write_info_ptr, text_ptr, num_text); } } #endif diff -ru4NwbB libpng-1.5.6/pngvalid.c libpng-1.5.7rc01/pngvalid.c --- libpng-1.5.6/pngvalid.c 2011-11-02 22:42:50.531808873 -0500 +++ libpng-1.5.7rc01/pngvalid.c 1969-12-31 18:00:00.000000000 -0600 @@ -1,9697 +0,0 @@ - -/* pngvalid.c - validate libpng by constructing then reading png files. - * - * Last changed in libpng 1.5.6 [(PENDING RELEASE)] - * Copyright (c) 2011 Glenn Randers-Pehrson - * Written by John Cunningham Bowler - * - * This code is released under the libpng license. - * For conditions of distribution and use, see the disclaimer - * and license in png.h - * - * NOTES: - * This is a C program that is intended to be linked against libpng. It - * generates bitmaps internally, stores them as PNG files (using the - * sequential write code) then reads them back (using the sequential - * read code) and validates that the result has the correct data. - * - * The program can be modified and extended to test the correctness of - * transformations performed by libpng. - */ - -#define _POSIX_SOURCE 1 - -#include "png.h" -#if PNG_LIBPNG_VER < 10500 -/* This delibarately lacks the PNG_CONST. */ -typedef png_byte *png_const_bytep; - -/* This is copied from 1.5.1 png.h: */ -#define PNG_INTERLACE_ADAM7_PASSES 7 -#define PNG_PASS_START_ROW(pass) (((1U&~(pass))<<(3-((pass)>>1)))&7) -#define PNG_PASS_START_COL(pass) (((1U& (pass))<<(3-(((pass)+1)>>1)))&7) -#define PNG_PASS_ROW_SHIFT(pass) ((pass)>2?(8-(pass))>>1:3) -#define PNG_PASS_COL_SHIFT(pass) ((pass)>1?(7-(pass))>>1:3) -#define PNG_PASS_ROWS(height, pass) (((height)+(((1<>PNG_PASS_ROW_SHIFT(pass)) -#define PNG_PASS_COLS(width, pass) (((width)+(((1<>PNG_PASS_COL_SHIFT(pass)) -#define PNG_ROW_FROM_PASS_ROW(yIn, pass) \ - (((yIn)<>(((7-(off))-(pass))<<2)) & 0xFU) | \ - ((0x01145AF0U>>(((7-(off))-(pass))<<2)) & 0xF0U)) -#define PNG_ROW_IN_INTERLACE_PASS(y, pass) \ - ((PNG_PASS_MASK(pass,0) >> ((y)&7)) & 1) -#define PNG_COL_IN_INTERLACE_PASS(x, pass) \ - ((PNG_PASS_MASK(pass,1) >> ((x)&7)) & 1) - -/* These are needed too for the default build: */ -#define PNG_WRITE_16BIT_SUPPORTED -#define PNG_READ_16BIT_SUPPORTED - -/* This comes from pnglibconf.h afer 1.5: */ -#define PNG_FP_1 100000 -#define PNG_GAMMA_THRESHOLD_FIXED\ - ((png_fixed_point)(PNG_GAMMA_THRESHOLD * PNG_FP_1)) -#endif - -#include "zlib.h" /* For crc32 */ - -#include /* For floating point constants */ -#include /* For malloc */ -#include /* For memcpy, memset */ -#include /* For floor */ - -/* Unused formal parameter errors are removed using the following macro which is - * expected to have no bad effects on performance. - */ -#ifndef UNUSED -# if defined(__GNUC__) || defined(_MSC_VER) -# define UNUSED(param) (void)param; -# else -# define UNUSED(param) -# endif -#endif - -/***************************** EXCEPTION HANDLING *****************************/ -#include "contrib/visupng/cexcept.h" - -#ifdef __cplusplus -# define this not_the_cpp_this -# define new not_the_cpp_new -# define voidcast(type, value) static_cast(value) -#else -# define voidcast(type, value) (value) -#endif /* __cplusplus */ - -struct png_store; -define_exception_type(struct png_store*); - -/* The following are macros to reduce typing everywhere where the well known - * name 'the_exception_context' must be defined. - */ -#define anon_context(ps) struct exception_context *the_exception_context = \ - &(ps)->exception_context -#define context(ps,fault) anon_context(ps); png_store *fault - -/******************************* UTILITIES ************************************/ -/* Error handling is particularly problematic in production code - error - * handlers often themselves have bugs which lead to programs that detect - * minor errors crashing. The following functions deal with one very - * common class of errors in error handlers - attempting to format error or - * warning messages into buffers that are too small. - */ -static size_t safecat(char *buffer, size_t bufsize, size_t pos, - PNG_CONST char *cat) -{ - while (pos < bufsize && cat != NULL && *cat != 0) - buffer[pos++] = *cat++; - - if (pos >= bufsize) - pos = bufsize-1; - - buffer[pos] = 0; - return pos; -} - -static size_t safecatn(char *buffer, size_t bufsize, size_t pos, int n) -{ - char number[64]; - sprintf(number, "%d", n); - return safecat(buffer, bufsize, pos, number); -} - -#ifdef PNG_READ_TRANSFORMS_SUPPORTED -static size_t safecatd(char *buffer, size_t bufsize, size_t pos, double d, - int precision) -{ - char number[64]; - sprintf(number, "%.*f", precision, d); - return safecat(buffer, bufsize, pos, number); -} -#endif - -static PNG_CONST char invalid[] = "invalid"; -static PNG_CONST char sep[] = ": "; - -static PNG_CONST char *colour_types[8] = -{ - "grayscale", invalid, "truecolour", "indexed-colour", - "grayscale with alpha", invalid, "truecolour with alpha", invalid -}; - -/* Convert a double precision value to fixed point. */ -static png_fixed_point -fix(double d) -{ - d = floor(d * PNG_FP_1 + .5); - return (png_fixed_point)d; -} - -/* Generate random bytes. This uses a boring repeatable algorithm and it - * is implemented here so that it gives the same set of numbers on every - * architecture. It's a linear congruential generator (Knuth or Sedgewick - * "Algorithms") but it comes from the 'feedback taps' table in Horowitz and - * Hill, "The Art of Electronics". - */ -static void -make_random_bytes(png_uint_32* seed, void* pv, size_t size) -{ - png_uint_32 u0 = seed[0], u1 = seed[1]; - png_bytep bytes = voidcast(png_bytep, pv); - - /* There are thirty three bits, the next bit in the sequence is bit-33 XOR - * bit-20. The top 1 bit is in u1, the bottom 32 are in u0. - */ - size_t i; - for (i=0; i> (20-8)) ^ ((u1 << 7) | (u0 >> (32-7)))) & 0xff; - u1 <<= 8; - u1 |= u0 >> 24; - u0 <<= 8; - u0 |= u; - *bytes++ = (png_byte)u; - } - - seed[0] = u0; - seed[1] = u1; -} - -static void -make_four_random_bytes(png_uint_32* seed, png_bytep bytes) -{ - make_random_bytes(seed, bytes, 4); -} - -static void -randomize(void *pv, size_t size) -{ - static png_uint_32 random_seed[2] = {0x56789abc, 0xd}; - make_random_bytes(random_seed, pv, size); -} - -#define RANDOMIZE(this) randomize(&(this), sizeof (this)) - -static unsigned int -random_mod(unsigned int max) -{ - unsigned int x; - - RANDOMIZE(x); - - return x % max; /* 0 .. max-1 */ -} - -static int -random_choice(void) -{ - unsigned char x; - - RANDOMIZE(x); - - return x & 1; -} - -/* A numeric ID based on PNG file characteristics. The 'do_interlace' field - * simply records whether pngvalid did the interlace itself or whether it - * was done by libpng. Width and height must be less than 256. 'palette' is an - * index of the palette to use for formats with a palette (0 otherwise.) - */ -#define FILEID(col, depth, palette, interlace, width, height, do_interlace) \ - ((png_uint_32)((col) + ((depth)<<3) + ((palette)<<8) + ((interlace)<<13) + \ - (((do_interlace)!=0)<<15) + ((width)<<16) + ((height)<<24))) - -#define COL_FROM_ID(id) ((png_byte)((id)& 0x7U)) -#define DEPTH_FROM_ID(id) ((png_byte)(((id) >> 3) & 0x1fU)) -#define PALETTE_FROM_ID(id) ((int)(((id) >> 8) & 0x1f)) -#define INTERLACE_FROM_ID(id) ((int)(((id) >> 13) & 0x3)) -#define DO_INTERLACE_FROM_ID(id) ((int)(((id)>>15) & 1)) -#define WIDTH_FROM_ID(id) (((id)>>16) & 0xff) -#define HEIGHT_FROM_ID(id) (((id)>>24) & 0xff) - -/* Utility to construct a standard name for a standard image. */ -static size_t -standard_name(char *buffer, size_t bufsize, size_t pos, png_byte colour_type, - int bit_depth, int npalette, int interlace_type, - png_uint_32 w, png_uint_32 h, int do_interlace) -{ - pos = safecat(buffer, bufsize, pos, colour_types[colour_type]); - if (npalette > 0) - { - pos = safecat(buffer, bufsize, pos, "["); - pos = safecatn(buffer, bufsize, pos, npalette); - pos = safecat(buffer, bufsize, pos, "]"); - } - pos = safecat(buffer, bufsize, pos, " "); - pos = safecatn(buffer, bufsize, pos, bit_depth); - pos = safecat(buffer, bufsize, pos, " bit"); - - if (interlace_type != PNG_INTERLACE_NONE) - { - pos = safecat(buffer, bufsize, pos, " interlaced"); - if (do_interlace) - pos = safecat(buffer, bufsize, pos, "(pngvalid)"); - else - pos = safecat(buffer, bufsize, pos, "(libpng)"); - } - - if (w > 0 || h > 0) - { - pos = safecat(buffer, bufsize, pos, " "); - pos = safecatn(buffer, bufsize, pos, w); - pos = safecat(buffer, bufsize, pos, "x"); - pos = safecatn(buffer, bufsize, pos, h); - } - - return pos; -} - -static size_t -standard_name_from_id(char *buffer, size_t bufsize, size_t pos, png_uint_32 id) -{ - return standard_name(buffer, bufsize, pos, COL_FROM_ID(id), - DEPTH_FROM_ID(id), PALETTE_FROM_ID(id), INTERLACE_FROM_ID(id), - WIDTH_FROM_ID(id), HEIGHT_FROM_ID(id), DO_INTERLACE_FROM_ID(id)); -} - -/* Convenience API and defines to list valid formats. Note that 16 bit read and - * write support is required to do 16 bit read tests (we must be able to make a - * 16 bit image to test!) - */ -#ifdef PNG_WRITE_16BIT_SUPPORTED -# define WRITE_BDHI 4 -# ifdef PNG_READ_16BIT_SUPPORTED -# define READ_BDHI 4 -# define DO_16BIT -# endif -#else -# define WRITE_BDHI 3 -#endif -#ifndef DO_16BIT -# define READ_BDHI 3 -#endif - -/* The following defines the number of different palettes to generate for - * each log bit depth of a colour type 3 standard image. - */ -#define PALETTE_COUNT(bit_depth) ((bit_depth) > 4 ? 1 : 16) - -static int -next_format(png_bytep colour_type, png_bytep bit_depth, int* palette_number) -{ - if (*bit_depth == 0) - { - *colour_type = 0, *bit_depth = 1, *palette_number = 0; - return 1; - } - - if (*colour_type == 3) - { - /* Add multiple palettes for colour type 3. */ - if (++*palette_number < PALETTE_COUNT(*bit_depth)) - return 1; - - *palette_number = 0; - } - - *bit_depth = (png_byte)(*bit_depth << 1); - - /* Palette images are restricted to 8 bit depth */ - if (*bit_depth <= 8 -# ifdef DO_16BIT - || (*colour_type != 3 && *bit_depth <= 16) -# endif - ) - return 1; - - /* Move to the next color type, or return 0 at the end. */ - switch (*colour_type) - { - case 0: - *colour_type = 2; - *bit_depth = 8; - return 1; - - case 2: - *colour_type = 3; - *bit_depth = 1; - return 1; - - case 3: - *colour_type = 4; - *bit_depth = 8; - return 1; - - case 4: - *colour_type = 6; - *bit_depth = 8; - return 1; - - default: - return 0; - } -} - -#ifdef PNG_READ_TRANSFORMS_SUPPORTED -static unsigned int -sample(png_const_bytep row, png_byte colour_type, png_byte bit_depth, - png_uint_32 x, unsigned int sample_index) -{ - png_uint_32 bit_index, result; - - /* Find a sample index for the desired sample: */ - x *= bit_depth; - bit_index = x; - - if ((colour_type & 1) == 0) /* !palette */ - { - if (colour_type & 2) - bit_index *= 3; - - if (colour_type & 4) - bit_index += x; /* Alpha channel */ - - /* Multiple channels; select one: */ - if (colour_type & (2+4)) - bit_index += sample_index * bit_depth; - } - - /* Return the sample from the row as an integer. */ - row += bit_index >> 3; - result = *row; - - if (bit_depth == 8) - return result; - - else if (bit_depth > 8) - return (result << 8) + *++row; - - /* Less than 8 bits per sample. */ - bit_index &= 7; - return (result >> (8-bit_index-bit_depth)) & ((1U<> 3] & ~destMask; - unsigned int sourceByte = fromBuffer[fromIndex >> 3]; - - /* Don't rely on << or >> supporting '0' here, just in case: */ - fromIndex &= 7; - if (fromIndex > 0) sourceByte <<= fromIndex; - if ((toIndex & 7) > 0) sourceByte >>= toIndex & 7; - - toBuffer[toIndex >> 3] = (png_byte)(destByte | (sourceByte & destMask)); - } - else /* One or more bytes */ - memmove(toBuffer+(toIndex>>3), fromBuffer+(fromIndex>>3), pixelSize>>3); -} - -/* Copy a complete row of pixels, taking into account potential partial - * bytes at the end. - */ -static void -row_copy(png_bytep toBuffer, png_const_bytep fromBuffer, unsigned int bitWidth) -{ - memcpy(toBuffer, fromBuffer, bitWidth >> 3); - - if ((bitWidth & 7) != 0) - { - unsigned int mask; - - toBuffer += bitWidth >> 3; - fromBuffer += bitWidth >> 3; - /* The remaining bits are in the top of the byte, the mask is the bits to - * retain. - */ - mask = 0xff >> (bitWidth & 7); - *toBuffer = (png_byte)((*toBuffer & mask) | (*fromBuffer & ~mask)); - } -} - -/* Compare pixels - they are assumed to start at the first byte in the - * given buffers. - */ -static int -pixel_cmp(png_const_bytep pa, png_const_bytep pb, png_uint_32 bit_width) -{ -#if PNG_LIBPNG_VER < 10506 - if (memcmp(pa, pb, bit_width>>3) == 0) - { - png_uint_32 p; - - if ((bit_width & 7) == 0) return 0; - - /* Ok, any differences? */ - p = pa[bit_width >> 3]; - p ^= pb[bit_width >> 3]; - - if (p == 0) return 0; - - /* There are, but they may not be significant, remove the bits - * after the end (the low order bits in PNG.) - */ - bit_width &= 7; - p >>= 8-bit_width; - - if (p == 0) return 0; - } -#else - /* From libpng-1.5.6 the overwrite should be fixed, so compare the trailing - * bits too: - */ - if (memcmp(pa, pb, (bit_width+7)>>3) == 0) - return 0; -#endif - - /* Return the index of the changed byte. */ - { - png_uint_32 where = 0; - - while (pa[where] == pb[where]) ++where; - return 1+where; - } -} - -/*************************** BASIC PNG FILE WRITING ***************************/ -/* A png_store takes data from the sequential writer or provides data - * to the sequential reader. It can also store the result of a PNG - * write for later retrieval. - */ -#define STORE_BUFFER_SIZE 500 /* arbitrary */ -typedef struct png_store_buffer -{ - struct png_store_buffer* prev; /* NOTE: stored in reverse order */ - png_byte buffer[STORE_BUFFER_SIZE]; -} png_store_buffer; - -#define FILE_NAME_SIZE 64 - -typedef struct store_palette_entry /* record of a single palette entry */ -{ - png_byte red; - png_byte green; - png_byte blue; - png_byte alpha; -} store_palette_entry, store_palette[256]; - -typedef struct png_store_file -{ - struct png_store_file* next; /* as many as you like... */ - char name[FILE_NAME_SIZE]; - png_uint_32 id; /* must be correct (see FILEID) */ - png_size_t datacount; /* In this (the last) buffer */ - png_store_buffer data; /* Last buffer in file */ - int npalette; /* Number of entries in palette */ - store_palette_entry* palette; /* May be NULL */ -} png_store_file; - -/* The following is a pool of memory allocated by a single libpng read or write - * operation. - */ -typedef struct store_pool -{ - struct png_store *store; /* Back pointer */ - struct store_memory *list; /* List of allocated memory */ - png_byte mark[4]; /* Before and after data */ - - /* Statistics for this run. */ - png_alloc_size_t max; /* Maximum single allocation */ - png_alloc_size_t current; /* Current allocation */ - png_alloc_size_t limit; /* Highest current allocation */ - png_alloc_size_t total; /* Total allocation */ - - /* Overall statistics (retained across successive runs). */ - png_alloc_size_t max_max; - png_alloc_size_t max_limit; - png_alloc_size_t max_total; -} store_pool; - -typedef struct png_store -{ - /* For cexcept.h exception handling - simply store one of these; - * the context is a self pointer but it may point to a different - * png_store (in fact it never does in this program.) - */ - struct exception_context - exception_context; - - unsigned int verbose :1; - unsigned int treat_warnings_as_errors :1; - unsigned int expect_error :1; - unsigned int expect_warning :1; - unsigned int saw_warning :1; - unsigned int speed :1; - unsigned int progressive :1; /* use progressive read */ - unsigned int validated :1; /* used as a temporary flag */ - int nerrors; - int nwarnings; - char test[128]; /* Name of test */ - char error[256]; - - /* Read fields */ - png_structp pread; /* Used to read a saved file */ - png_infop piread; - png_store_file* current; /* Set when reading */ - png_store_buffer* next; /* Set when reading */ - png_size_t readpos; /* Position in *next */ - png_byte* image; /* Buffer for reading interlaced images */ - png_size_t cb_image; /* Size of this buffer */ - png_size_t cb_row; /* Row size of the image(s) */ - png_uint_32 image_h; /* Number of rows in a single image */ - store_pool read_memory_pool; - - /* Write fields */ - png_store_file* saved; - png_structp pwrite; /* Used when writing a new file */ - png_infop piwrite; - png_size_t writepos; /* Position in .new */ - char wname[FILE_NAME_SIZE]; - png_store_buffer new; /* The end of the new PNG file being written. */ - store_pool write_memory_pool; - store_palette_entry* palette; - int npalette; -} png_store; - -/* Initialization and cleanup */ -static void -store_pool_mark(png_bytep mark) -{ - static png_uint_32 store_seed[2] = { 0x12345678, 1}; - - make_four_random_bytes(store_seed, mark); -} - -/* Use this for random 32 bit values; this function makes sure the result is - * non-zero. - */ -static png_uint_32 -random_32(void) -{ - - for(;;) - { - png_byte mark[4]; - png_uint_32 result; - - store_pool_mark(mark); - result = png_get_uint_32(mark); - - if (result != 0) - return result; - } -} - -static void -store_pool_init(png_store *ps, store_pool *pool) -{ - memset(pool, 0, sizeof *pool); - - pool->store = ps; - pool->list = NULL; - pool->max = pool->current = pool->limit = pool->total = 0; - pool->max_max = pool->max_limit = pool->max_total = 0; - store_pool_mark(pool->mark); -} - -static void -store_init(png_store* ps) -{ - memset(ps, 0, sizeof *ps); - init_exception_context(&ps->exception_context); - store_pool_init(ps, &ps->read_memory_pool); - store_pool_init(ps, &ps->write_memory_pool); - ps->verbose = 0; - ps->treat_warnings_as_errors = 0; - ps->expect_error = 0; - ps->expect_warning = 0; - ps->saw_warning = 0; - ps->speed = 0; - ps->progressive = 0; - ps->validated = 0; - ps->nerrors = ps->nwarnings = 0; - ps->pread = NULL; - ps->piread = NULL; - ps->saved = ps->current = NULL; - ps->next = NULL; - ps->readpos = 0; - ps->image = NULL; - ps->cb_image = 0; - ps->cb_row = 0; - ps->image_h = 0; - ps->pwrite = NULL; - ps->piwrite = NULL; - ps->writepos = 0; - ps->new.prev = NULL; - ps->palette = NULL; - ps->npalette = 0; -} - -static void -store_freebuffer(png_store_buffer* psb) -{ - if (psb->prev) - { - store_freebuffer(psb->prev); - free(psb->prev); - psb->prev = NULL; - } -} - -static void -store_freenew(png_store *ps) -{ - store_freebuffer(&ps->new); - ps->writepos = 0; - if (ps->palette != NULL) - { - free(ps->palette); - ps->palette = NULL; - ps->npalette = 0; - } -} - -static void -store_storenew(png_store *ps) -{ - png_store_buffer *pb; - - if (ps->writepos != STORE_BUFFER_SIZE) - png_error(ps->pwrite, "invalid store call"); - - pb = voidcast(png_store_buffer*, malloc(sizeof *pb)); - - if (pb == NULL) - png_error(ps->pwrite, "store new: OOM"); - - *pb = ps->new; - ps->new.prev = pb; - ps->writepos = 0; -} - -static void -store_freefile(png_store_file **ppf) -{ - if (*ppf != NULL) - { - store_freefile(&(*ppf)->next); - - store_freebuffer(&(*ppf)->data); - (*ppf)->datacount = 0; - if ((*ppf)->palette != NULL) - { - free((*ppf)->palette); - (*ppf)->palette = NULL; - (*ppf)->npalette = 0; - } - free(*ppf); - *ppf = NULL; - } -} - -/* Main interface to file storeage, after writing a new PNG file (see the API - * below) call store_storefile to store the result with the given name and id. - */ -static void -store_storefile(png_store *ps, png_uint_32 id) -{ - png_store_file *pf = voidcast(png_store_file*, malloc(sizeof *pf)); - if (pf == NULL) - png_error(ps->pwrite, "storefile: OOM"); - safecat(pf->name, sizeof pf->name, 0, ps->wname); - pf->id = id; - pf->data = ps->new; - pf->datacount = ps->writepos; - ps->new.prev = NULL; - ps->writepos = 0; - pf->palette = ps->palette; - pf->npalette = ps->npalette; - ps->palette = 0; - ps->npalette = 0; - - /* And save it. */ - pf->next = ps->saved; - ps->saved = pf; -} - -/* Generate an error message (in the given buffer) */ -static size_t -store_message(png_store *ps, png_structp pp, char *buffer, size_t bufsize, - size_t pos, PNG_CONST char *msg) -{ - if (pp != NULL && pp == ps->pread) - { - /* Reading a file */ - pos = safecat(buffer, bufsize, pos, "read: "); - - if (ps->current != NULL) - { - pos = safecat(buffer, bufsize, pos, ps->current->name); - pos = safecat(buffer, bufsize, pos, sep); - } - } - - else if (pp != NULL && pp == ps->pwrite) - { - /* Writing a file */ - pos = safecat(buffer, bufsize, pos, "write: "); - pos = safecat(buffer, bufsize, pos, ps->wname); - pos = safecat(buffer, bufsize, pos, sep); - } - - else - { - /* Neither reading nor writing (or a memory error in struct delete) */ - pos = safecat(buffer, bufsize, pos, "pngvalid: "); - } - - if (ps->test[0] != 0) - { - pos = safecat(buffer, bufsize, pos, ps->test); - pos = safecat(buffer, bufsize, pos, sep); - } - pos = safecat(buffer, bufsize, pos, msg); - return pos; -} - -/* Verbose output to the error stream: */ -static void -store_verbose(png_store *ps, png_structp pp, png_const_charp prefix, - png_const_charp message) -{ - char buffer[512]; - - if (prefix) - fputs(prefix, stderr); - - (void)store_message(ps, pp, buffer, sizeof buffer, 0, message); - fputs(buffer, stderr); - fputc('\n', stderr); -} - -/* Log an error or warning - the relevant count is always incremented. */ -static void -store_log(png_store* ps, png_structp pp, png_const_charp message, int is_error) -{ - /* The warning is copied to the error buffer if there are no errors and it is - * the first warning. The error is copied to the error buffer if it is the - * first error (overwriting any prior warnings). - */ - if (is_error ? (ps->nerrors)++ == 0 : - (ps->nwarnings)++ == 0 && ps->nerrors == 0) - store_message(ps, pp, ps->error, sizeof ps->error, 0, message); - - if (ps->verbose) - store_verbose(ps, pp, is_error ? "error: " : "warning: ", message); -} - -/* Functions to use as PNG callbacks. */ -static void -store_error(png_structp pp, png_const_charp message) /* PNG_NORETURN */ -{ - png_store *ps = voidcast(png_store*, png_get_error_ptr(pp)); - - if (!ps->expect_error) - store_log(ps, pp, message, 1 /* error */); - - /* And finally throw an exception. */ - { - struct exception_context *the_exception_context = &ps->exception_context; - Throw ps; - } -} - -static void -store_warning(png_structp pp, png_const_charp message) -{ - png_store *ps = voidcast(png_store*, png_get_error_ptr(pp)); - - if (!ps->expect_warning) - store_log(ps, pp, message, 0 /* warning */); - else - ps->saw_warning = 1; -} - -/* These somewhat odd functions are used when reading an image to ensure that - * the buffer is big enough, the png_structp is for errors. - */ -/* Return a single row from the correct image. */ -static png_bytep -store_image_row(PNG_CONST png_store* ps, png_structp pp, int nImage, - png_uint_32 y) -{ - png_size_t coffset = (nImage * ps->image_h + y) * (ps->cb_row + 5) + 2; - - if (ps->image == NULL) - png_error(pp, "no allocated image"); - - if (coffset + ps->cb_row + 3 > ps->cb_image) - png_error(pp, "image too small"); - - return ps->image + coffset; -} - -static void -store_image_free(png_store *ps, png_structp pp) -{ - if (ps->image != NULL) - { - png_bytep image = ps->image; - - if (image[-1] != 0xed || image[ps->cb_image] != 0xfe) - { - if (pp != NULL) - png_error(pp, "png_store image overwrite (1)"); - else - store_log(ps, NULL, "png_store image overwrite (2)", 1); - } - - ps->image = NULL; - ps->cb_image = 0; - --image; - free(image); - } -} - -static void -store_ensure_image(png_store *ps, png_structp pp, int nImages, png_size_t cbRow, - png_uint_32 cRows) -{ - png_size_t cb = nImages * cRows * (cbRow + 5); - - if (ps->cb_image < cb) - { - png_bytep image; - - store_image_free(ps, pp); - - /* The buffer is deliberately mis-aligned. */ - image = voidcast(png_bytep, malloc(cb+2)); - if (image == NULL) - { - /* Called from the startup - ignore the error for the moment. */ - if (pp == NULL) - return; - - png_error(pp, "OOM allocating image buffer"); - } - - /* These magic tags are used to detect overwrites above. */ - ++image; - image[-1] = 0xed; - image[cb] = 0xfe; - - ps->image = image; - ps->cb_image = cb; - } - - /* We have an adequate sized image; lay out the rows. There are 2 bytes at - * the start and three at the end of each (this ensures that the row - * alignment starts out odd - 2+1 and changes for larger images on each row.) - */ - ps->cb_row = cbRow; - ps->image_h = cRows; - - /* For error checking, the whole buffer is set to 10110010 (0xb2 - 178). - * This deliberately doesn't match the bits in the size test image which are - * outside the image; these are set to 0xff (all 1). To make the row - * comparison work in the 'size' test case the size rows are pre-initialized - * to the same value prior to calling 'standard_row'. - */ - memset(ps->image, 178, cb); - - /* Then put in the marks. */ - while (--nImages >= 0) - { - png_uint_32 y; - - for (y=0; yimage; - - if (image[-1] != 0xed || image[ps->cb_image] != 0xfe) - png_error(pp, "image overwrite"); - else - { - png_size_t cbRow = ps->cb_row; - png_uint_32 rows = ps->image_h; - - image += iImage * (cbRow+5) * ps->image_h; - - image += 2; /* skip image first row markers */ - - while (rows-- > 0) - { - if (image[-2] != 190 || image[-1] != 239) - png_error(pp, "row start overwritten"); - - if (image[cbRow] != 222 || image[cbRow+1] != 173 || - image[cbRow+2] != 17) - png_error(pp, "row end overwritten"); - - image += cbRow+5; - } - } -} - -static void -store_write(png_structp pp, png_bytep pb, png_size_t st) -{ - png_store *ps = voidcast(png_store*, png_get_io_ptr(pp)); - - if (ps->pwrite != pp) - png_error(pp, "store state damaged"); - - while (st > 0) - { - size_t cb; - - if (ps->writepos >= STORE_BUFFER_SIZE) - store_storenew(ps); - - cb = st; - - if (cb > STORE_BUFFER_SIZE - ps->writepos) - cb = STORE_BUFFER_SIZE - ps->writepos; - - memcpy(ps->new.buffer + ps->writepos, pb, cb); - pb += cb; - st -= cb; - ps->writepos += cb; - } -} - -static void -store_flush(png_structp pp) -{ - UNUSED(pp) /*DOES NOTHING*/ -} - -static size_t -store_read_buffer_size(png_store *ps) -{ - /* Return the bytes available for read in the current buffer. */ - if (ps->next != &ps->current->data) - return STORE_BUFFER_SIZE; - - return ps->current->datacount; -} - -#ifdef PNG_READ_TRANSFORMS_SUPPORTED -/* Return total bytes available for read. */ -static size_t -store_read_buffer_avail(png_store *ps) -{ - if (ps->current != NULL && ps->next != NULL) - { - png_store_buffer *next = &ps->current->data; - size_t cbAvail = ps->current->datacount; - - while (next != ps->next && next != NULL) - { - next = next->prev; - cbAvail += STORE_BUFFER_SIZE; - } - - if (next != ps->next) - png_error(ps->pread, "buffer read error"); - - if (cbAvail > ps->readpos) - return cbAvail - ps->readpos; - } - - return 0; -} -#endif - -static int -store_read_buffer_next(png_store *ps) -{ - png_store_buffer *pbOld = ps->next; - png_store_buffer *pbNew = &ps->current->data; - if (pbOld != pbNew) - { - while (pbNew != NULL && pbNew->prev != pbOld) - pbNew = pbNew->prev; - - if (pbNew != NULL) - { - ps->next = pbNew; - ps->readpos = 0; - return 1; - } - - png_error(ps->pread, "buffer lost"); - } - - return 0; /* EOF or error */ -} - -/* Need separate implementation and callback to allow use of the same code - * during progressive read, where the io_ptr is set internally by libpng. - */ -static void -store_read_imp(png_store *ps, png_bytep pb, png_size_t st) -{ - if (ps->current == NULL || ps->next == NULL) - png_error(ps->pread, "store state damaged"); - - while (st > 0) - { - size_t cbAvail = store_read_buffer_size(ps) - ps->readpos; - - if (cbAvail > 0) - { - if (cbAvail > st) cbAvail = st; - memcpy(pb, ps->next->buffer + ps->readpos, cbAvail); - st -= cbAvail; - pb += cbAvail; - ps->readpos += cbAvail; - } - - else if (!store_read_buffer_next(ps)) - png_error(ps->pread, "read beyond end of file"); - } -} - -static void -store_read(png_structp pp, png_bytep pb, png_size_t st) -{ - png_store *ps = voidcast(png_store*, png_get_io_ptr(pp)); - - if (ps == NULL || ps->pread != pp) - png_error(pp, "bad store read call"); - - store_read_imp(ps, pb, st); -} - -static void -store_progressive_read(png_store *ps, png_structp pp, png_infop pi) -{ - /* Notice that a call to store_read will cause this function to fail because - * readpos will be set. - */ - if (ps->pread != pp || ps->current == NULL || ps->next == NULL) - png_error(pp, "store state damaged (progressive)"); - - do - { - if (ps->readpos != 0) - png_error(pp, "store_read called during progressive read"); - - png_process_data(pp, pi, ps->next->buffer, store_read_buffer_size(ps)); - } - while (store_read_buffer_next(ps)); -} - -/* The caller must fill this in: */ -static store_palette_entry * -store_write_palette(png_store *ps, int npalette) -{ - if (ps->pwrite == NULL) - store_log(ps, NULL, "attempt to write palette without write stream", 1); - - if (ps->palette != NULL) - png_error(ps->pwrite, "multiple store_write_palette calls"); - - /* This function can only return NULL if called with '0'! */ - if (npalette > 0) - { - ps->palette = voidcast(store_palette_entry*, malloc(npalette * - sizeof *ps->palette)); - - if (ps->palette == NULL) - png_error(ps->pwrite, "store new palette: OOM"); - - ps->npalette = npalette; - } - - return ps->palette; -} - -static store_palette_entry * -store_current_palette(png_store *ps, int *npalette) -{ - /* This is an internal error (the call has been made outside a read - * operation.) - */ - if (ps->current == NULL) - store_log(ps, ps->pread, "no current stream for palette", 1); - - /* The result may be null if there is no palette. */ - *npalette = ps->current->npalette; - return ps->current->palette; -} - -/***************************** MEMORY MANAGEMENT*** ***************************/ -/* A store_memory is simply the header for an allocated block of memory. The - * pointer returned to libpng is just after the end of the header block, the - * allocated memory is followed by a second copy of the 'mark'. - */ -typedef struct store_memory -{ - store_pool *pool; /* Originating pool */ - struct store_memory *next; /* Singly linked list */ - png_alloc_size_t size; /* Size of memory allocated */ - png_byte mark[4]; /* ID marker */ -} store_memory; - -/* Handle a fatal error in memory allocation. This calls png_error if the - * libpng struct is non-NULL, else it outputs a message and returns. This means - * that a memory problem while libpng is running will abort (png_error) the - * handling of particular file while one in cleanup (after the destroy of the - * struct has returned) will simply keep going and free (or attempt to free) - * all the memory. - */ -static void -store_pool_error(png_store *ps, png_structp pp, PNG_CONST char *msg) -{ - if (pp != NULL) - png_error(pp, msg); - - /* Else we have to do it ourselves. png_error eventually calls store_log, - * above. store_log accepts a NULL png_structp - it just changes what gets - * output by store_message. - */ - store_log(ps, pp, msg, 1 /* error */); -} - -static void -store_memory_free(png_structp pp, store_pool *pool, store_memory *memory) -{ - /* Note that pp may be NULL (see store_pool_delete below), the caller has - * found 'memory' in pool->list *and* unlinked this entry, so this is a valid - * pointer (for sure), but the contents may have been trashed. - */ - if (memory->pool != pool) - store_pool_error(pool->store, pp, "memory corrupted (pool)"); - - else if (memcmp(memory->mark, pool->mark, sizeof memory->mark) != 0) - store_pool_error(pool->store, pp, "memory corrupted (start)"); - - /* It should be safe to read the size field now. */ - else - { - png_alloc_size_t cb = memory->size; - - if (cb > pool->max) - store_pool_error(pool->store, pp, "memory corrupted (size)"); - - else if (memcmp((png_bytep)(memory+1)+cb, pool->mark, sizeof pool->mark) - != 0) - store_pool_error(pool->store, pp, "memory corrupted (end)"); - - /* Finally give the library a chance to find problems too: */ - else - { - pool->current -= cb; - free(memory); - } - } -} - -static void -store_pool_delete(png_store *ps, store_pool *pool) -{ - if (pool->list != NULL) - { - fprintf(stderr, "%s: %s %s: memory lost (list follows):\n", ps->test, - pool == &ps->read_memory_pool ? "read" : "write", - pool == &ps->read_memory_pool ? (ps->current != NULL ? - ps->current->name : "unknown file") : ps->wname); - ++ps->nerrors; - - do - { - store_memory *next = pool->list; - pool->list = next->next; - next->next = NULL; - - fprintf(stderr, "\t%lu bytes @ %p\n", - (unsigned long)next->size, (PNG_CONST void*)(next+1)); - /* The NULL means this will always return, even if the memory is - * corrupted. - */ - store_memory_free(NULL, pool, next); - } - while (pool->list != NULL); - } - - /* And reset the other fields too for the next time. */ - if (pool->max > pool->max_max) pool->max_max = pool->max; - pool->max = 0; - if (pool->current != 0) /* unexpected internal error */ - fprintf(stderr, "%s: %s %s: memory counter mismatch (internal error)\n", - ps->test, pool == &ps->read_memory_pool ? "read" : "write", - pool == &ps->read_memory_pool ? (ps->current != NULL ? - ps->current->name : "unknown file") : ps->wname); - pool->current = 0; - - if (pool->limit > pool->max_limit) - pool->max_limit = pool->limit; - - pool->limit = 0; - - if (pool->total > pool->max_total) - pool->max_total = pool->total; - - pool->total = 0; - - /* Get a new mark too. */ - store_pool_mark(pool->mark); -} - -/* The memory callbacks: */ -static png_voidp -store_malloc(png_structp pp, png_alloc_size_t cb) -{ - store_pool *pool = voidcast(store_pool*, png_get_mem_ptr(pp)); - store_memory *new = voidcast(store_memory*, malloc(cb + (sizeof *new) + - (sizeof pool->mark))); - - if (new != NULL) - { - if (cb > pool->max) - pool->max = cb; - - pool->current += cb; - - if (pool->current > pool->limit) - pool->limit = pool->current; - - pool->total += cb; - - new->size = cb; - memcpy(new->mark, pool->mark, sizeof new->mark); - memcpy((png_byte*)(new+1) + cb, pool->mark, sizeof pool->mark); - new->pool = pool; - new->next = pool->list; - pool->list = new; - ++new; - } - - else - store_pool_error(pool->store, pp, "out of memory"); - - return new; -} - -static void -store_free(png_structp pp, png_voidp memory) -{ - store_pool *pool = voidcast(store_pool*, png_get_mem_ptr(pp)); - store_memory *this = voidcast(store_memory*, memory), **test; - - /* First check that this 'memory' really is valid memory - it must be in the - * pool list. If it is, use the shared memory_free function to free it. - */ - --this; - for (test = &pool->list; *test != this; test = &(*test)->next) - { - if (*test == NULL) - { - store_pool_error(pool->store, pp, "bad pointer to free"); - return; - } - } - - /* Unlink this entry, *test == this. */ - *test = this->next; - this->next = NULL; - store_memory_free(pp, pool, this); -} - -/* Setup functions. */ -/* Cleanup when aborting a write or after storing the new file. */ -static void -store_write_reset(png_store *ps) -{ - if (ps->pwrite != NULL) - { - anon_context(ps); - - Try - png_destroy_write_struct(&ps->pwrite, &ps->piwrite); - - Catch_anonymous - { - /* memory corruption: continue. */ - } - - ps->pwrite = NULL; - ps->piwrite = NULL; - } - - /* And make sure that all the memory has been freed - this will output - * spurious errors in the case of memory corruption above, but this is safe. - */ - store_pool_delete(ps, &ps->write_memory_pool); - - store_freenew(ps); -} - -/* The following is the main write function, it returns a png_struct and, - * optionally, a png_info suitable for writiing a new PNG file. Use - * store_storefile above to record this file after it has been written. The - * returned libpng structures as destroyed by store_write_reset above. - */ -static png_structp -set_store_for_write(png_store *ps, png_infopp ppi, - PNG_CONST char * volatile name) -{ - anon_context(ps); - - Try - { - if (ps->pwrite != NULL) - png_error(ps->pwrite, "write store already in use"); - - store_write_reset(ps); - safecat(ps->wname, sizeof ps->wname, 0, name); - - /* Don't do the slow memory checks if doing a speed test. */ - if (ps->speed) - ps->pwrite = png_create_write_struct(PNG_LIBPNG_VER_STRING, - ps, store_error, store_warning); - - else - ps->pwrite = png_create_write_struct_2(PNG_LIBPNG_VER_STRING, - ps, store_error, store_warning, &ps->write_memory_pool, - store_malloc, store_free); - - png_set_write_fn(ps->pwrite, ps, store_write, store_flush); - - if (ppi != NULL) - *ppi = ps->piwrite = png_create_info_struct(ps->pwrite); - } - - Catch_anonymous - return NULL; - - return ps->pwrite; -} - -/* Cleanup when finished reading (either due to error or in the success case). - */ -static void -store_read_reset(png_store *ps) -{ - if (ps->pread != NULL) - { - anon_context(ps); - - Try - png_destroy_read_struct(&ps->pread, &ps->piread, NULL); - - Catch_anonymous - { - /* error already output: continue */ - } - - ps->pread = NULL; - ps->piread = NULL; - } - - /* Always do this to be safe. */ - store_pool_delete(ps, &ps->read_memory_pool); - - ps->current = NULL; - ps->next = NULL; - ps->readpos = 0; - ps->validated = 0; -} - -static void -store_read_set(png_store *ps, png_uint_32 id) -{ - png_store_file *pf = ps->saved; - - while (pf != NULL) - { - if (pf->id == id) - { - ps->current = pf; - ps->next = NULL; - store_read_buffer_next(ps); - return; - } - - pf = pf->next; - } - - { - size_t pos; - char msg[FILE_NAME_SIZE+64]; - - pos = standard_name_from_id(msg, sizeof msg, 0, id); - pos = safecat(msg, sizeof msg, pos, ": file not found"); - png_error(ps->pread, msg); - } -} - -/* The main interface for reading a saved file - pass the id number of the file - * to retrieve. Ids must be unique or the earlier file will be hidden. The API - * returns a png_struct and, optionally, a png_info. Both of these will be - * destroyed by store_read_reset above. - */ -static png_structp -set_store_for_read(png_store *ps, png_infopp ppi, png_uint_32 id, - PNG_CONST char *name) -{ - /* Set the name for png_error */ - safecat(ps->test, sizeof ps->test, 0, name); - - if (ps->pread != NULL) - png_error(ps->pread, "read store already in use"); - - store_read_reset(ps); - - /* Both the create APIs can return NULL if used in their default mode - * (because there is no other way of handling an error because the jmp_buf - * by default is stored in png_struct and that has not been allocated!) - * However, given that store_error works correctly in these circumstances - * we don't ever expect NULL in this program. - */ - if (ps->speed) - ps->pread = png_create_read_struct(PNG_LIBPNG_VER_STRING, ps, - store_error, store_warning); - - else - ps->pread = png_create_read_struct_2(PNG_LIBPNG_VER_STRING, ps, - store_error, store_warning, &ps->read_memory_pool, store_malloc, - store_free); - - if (ps->pread == NULL) - { - struct exception_context *the_exception_context = &ps->exception_context; - - store_log(ps, NULL, "png_create_read_struct returned NULL (unexpected)", - 1 /*error*/); - - Throw ps; - } - - store_read_set(ps, id); - - if (ppi != NULL) - *ppi = ps->piread = png_create_info_struct(ps->pread); - - return ps->pread; -} - -/* The overall cleanup of a store simply calls the above then removes all the - * saved files. This does not delete the store itself. - */ -static void -store_delete(png_store *ps) -{ - store_write_reset(ps); - store_read_reset(ps); - store_freefile(&ps->saved); - store_image_free(ps, NULL); -} - -/*********************** PNG FILE MODIFICATION ON READ ************************/ -/* Files may be modified on read. The following structure contains a complete - * png_store together with extra members to handle modification and a special - * read callback for libpng. To use this the 'modifications' field must be set - * to a list of png_modification structures that actually perform the - * modification, otherwise a png_modifier is functionally equivalent to a - * png_store. There is a special read function, set_modifier_for_read, which - * replaces set_store_for_read. - */ -typedef enum modifier_state -{ - modifier_start, /* Initial value */ - modifier_signature, /* Have a signature */ - modifier_IHDR /* Have an IHDR */ -} modifier_state; - -typedef struct CIE_color -{ - /* A single CIE tristimulus value, representing the unique response of a - * standard observer to a variety of light spectra. The observer recognizes - * all spectra that produce this response as the same color, therefore this - * is effectively a description of a color. - */ - double X, Y, Z; -} CIE_color; - -static double -chromaticity_x(CIE_color c) -{ - return c.X / (c.X + c.Y + c.Z); -} - -static double -chromaticity_y(CIE_color c) -{ - return c.Y / (c.X + c.Y + c.Z); -} - -typedef struct color_encoding -{ - /* A description of an (R,G,B) encoding of color (as defined above); this - * includes the actual colors of the (R,G,B) triples (1,0,0), (0,1,0) and - * (0,0,1) plus an encoding value that is used to encode the linear - * components R, G and B to give the actual values R^gamma, G^gamma and - * B^gamma that are stored. - */ - double gamma; /* Encoding (file) gamma of space */ - CIE_color red, green, blue; /* End points */ -} color_encoding; - -static CIE_color -white_point(PNG_CONST color_encoding *encoding) -{ - CIE_color white; - - white.X = encoding->red.X + encoding->green.X + encoding->blue.X; - white.Y = encoding->red.Y + encoding->green.Y + encoding->blue.Y; - white.Z = encoding->red.Z + encoding->green.Z + encoding->blue.Z; - - return white; -} - -static void -normalize_color_encoding(color_encoding *encoding) -{ - PNG_CONST double whiteY = encoding->red.Y + encoding->green.Y + - encoding->blue.Y; - - if (whiteY != 1) - { - encoding->red.X /= whiteY; - encoding->red.Y /= whiteY; - encoding->red.Z /= whiteY; - encoding->green.X /= whiteY; - encoding->green.Y /= whiteY; - encoding->green.Z /= whiteY; - encoding->blue.X /= whiteY; - encoding->blue.Y /= whiteY; - encoding->blue.Z /= whiteY; - } -} - -static size_t -safecat_color_encoding(char *buffer, size_t bufsize, size_t pos, - PNG_CONST color_encoding *e, double encoding_gamma) -{ - if (e != 0) - { - if (encoding_gamma != 0) - pos = safecat(buffer, bufsize, pos, "("); - pos = safecat(buffer, bufsize, pos, "R("); - pos = safecatd(buffer, bufsize, pos, e->red.X, 4); - pos = safecat(buffer, bufsize, pos, ","); - pos = safecatd(buffer, bufsize, pos, e->red.Y, 4); - pos = safecat(buffer, bufsize, pos, ","); - pos = safecatd(buffer, bufsize, pos, e->red.Z, 4); - pos = safecat(buffer, bufsize, pos, "),G("); - pos = safecatd(buffer, bufsize, pos, e->green.X, 4); - pos = safecat(buffer, bufsize, pos, ","); - pos = safecatd(buffer, bufsize, pos, e->green.Y, 4); - pos = safecat(buffer, bufsize, pos, ","); - pos = safecatd(buffer, bufsize, pos, e->green.Z, 4); - pos = safecat(buffer, bufsize, pos, "),B("); - pos = safecatd(buffer, bufsize, pos, e->blue.X, 4); - pos = safecat(buffer, bufsize, pos, ","); - pos = safecatd(buffer, bufsize, pos, e->blue.Y, 4); - pos = safecat(buffer, bufsize, pos, ","); - pos = safecatd(buffer, bufsize, pos, e->blue.Z, 4); - pos = safecat(buffer, bufsize, pos, ")"); - if (encoding_gamma != 0) - pos = safecat(buffer, bufsize, pos, ")"); - } - - if (encoding_gamma != 0) - { - pos = safecat(buffer, bufsize, pos, "^"); - pos = safecatd(buffer, bufsize, pos, encoding_gamma, 5); - } - - return pos; -} - -typedef struct png_modifier -{ - png_store this; /* I am a png_store */ - struct png_modification *modifications; /* Changes to make */ - - modifier_state state; /* My state */ - - /* Information from IHDR: */ - png_byte bit_depth; /* From IHDR */ - png_byte colour_type; /* From IHDR */ - - /* While handling PLTE, IDAT and IEND these chunks may be pended to allow - * other chunks to be inserted. - */ - png_uint_32 pending_len; - png_uint_32 pending_chunk; - - /* Test values */ - double *gammas; - unsigned int ngammas; - unsigned int ngamma_tests; /* Number of gamma tests to run*/ - double current_gamma; /* 0 if not set */ - PNG_CONST color_encoding *encodings; - unsigned int nencodings; - PNG_CONST color_encoding *current_encoding; /* If an encoding has been set */ - unsigned int encoding_counter; /* For iteration */ - int encoding_ignored; /* Something overwrote it */ - - /* Control variables used to iterate through possible encodings, the - * following must be set to 0 and tested by the function that uses the - * png_modifier because the modifier only sets it to 1 (true.) - */ - unsigned int repeat :1; /* Repeat this transform test. */ - unsigned int test_uses_encoding :1; - - /* Lowest sbit to test (libpng fails for sbit < 8) */ - png_byte sbitlow; - - /* Error control - these are the limits on errors accepted by the gamma tests - * below. - */ - double maxout8; /* Maximum output value error */ - double maxabs8; /* Absolute sample error 0..1 */ - double maxcalc8; /* Absolute sample error 0..1 */ - double maxpc8; /* Percentage sample error 0..100% */ - double maxout16; /* Maximum output value error */ - double maxabs16; /* Absolute sample error 0..1 */ - double maxcalc16;/* Absolute sample error 0..1 */ - double maxpc16; /* Percentage sample error 0..100% */ - - /* This is set by transforms that need to allow a higher limit, it is an - * internal check on pngvalid to ensure that the calculated error limits are - * not ridiculous; without this it is too easy to make a mistake in pngvalid - * that allows any value through. - */ - double limit; /* limit on error values, normally 4E-3 */ - - /* Log limits - values above this are logged, but not necessarily - * warned. - */ - double log8; /* Absolute error in 8 bits to log */ - double log16; /* Absolute error in 16 bits to log */ - - /* Logged 8 and 16 bit errors ('output' values): */ - double error_gray_2; - double error_gray_4; - double error_gray_8; - double error_gray_16; - double error_color_8; - double error_color_16; - double error_indexed; - - /* Flags: */ - /* Whether to call png_read_update_info, not png_read_start_image, and how - * many times to call it. - */ - int use_update_info; - - /* Whether or not to interlace. */ - int interlace_type :9; /* int, but must store '1' */ - - /* Run the standard tests? */ - unsigned int test_standard :1; - - /* Run the odd-sized image and interlace read/write tests? */ - unsigned int test_size :1; - - /* Run tests on reading with a combiniation of transforms, */ - unsigned int test_transform :1; - - /* When to use the use_input_precision option: */ - unsigned int use_input_precision :1; - unsigned int use_input_precision_sbit :1; - unsigned int use_input_precision_16to8 :1; - - /* If set assume that the calculation bit depth is set by the input - * precision, not the output precision. - */ - unsigned int calculations_use_input_precision :1; - - /* If set assume that the calculations are done in 16 bits even if both input - * and output are 8 bit or less. - */ - unsigned int assume_16_bit_calculations :1; - - /* Which gamma tests to run: */ - unsigned int test_gamma_threshold :1; - unsigned int test_gamma_transform :1; /* main tests */ - unsigned int test_gamma_sbit :1; - unsigned int test_gamma_scale16 :1; - unsigned int test_gamma_background :1; - unsigned int test_gamma_alpha_mode :1; - unsigned int test_gamma_expand16 :1; - unsigned int test_exhaustive :1; - - unsigned int log :1; /* Log max error */ - - /* Buffer information, the buffer size limits the size of the chunks that can - * be modified - they must fit (including header and CRC) into the buffer! - */ - size_t flush; /* Count of bytes to flush */ - size_t buffer_count; /* Bytes in buffer */ - size_t buffer_position; /* Position in buffer */ - png_byte buffer[1024]; -} png_modifier; - -/* This returns true if the test should be stopped now because it has already - * failed and it is running silently. - */ -static int fail(png_modifier *pm) -{ - return !pm->log && !pm->this.verbose && (pm->this.nerrors > 0 || - (pm->this.treat_warnings_as_errors && pm->this.nwarnings > 0)); -} - -static void -modifier_init(png_modifier *pm) -{ - memset(pm, 0, sizeof *pm); - store_init(&pm->this); - pm->modifications = NULL; - pm->state = modifier_start; - pm->sbitlow = 1U; - pm->ngammas = 0; - pm->ngamma_tests = 0; - pm->gammas = 0; - pm->current_gamma = 0; - pm->encodings = 0; - pm->nencodings = 0; - pm->current_encoding = 0; - pm->encoding_counter = 0; - pm->encoding_ignored = 0; - pm->repeat = 0; - pm->test_uses_encoding = 0; - pm->maxout8 = pm->maxpc8 = pm->maxabs8 = pm->maxcalc8 = 0; - pm->maxout16 = pm->maxpc16 = pm->maxabs16 = pm->maxcalc16 = 0; - pm->limit = 4E-3; - pm->log8 = pm->log16 = 0; /* Means 'off' */ - pm->error_gray_2 = pm->error_gray_4 = pm->error_gray_8 = 0; - pm->error_gray_16 = pm->error_color_8 = pm->error_color_16 = 0; - pm->error_indexed = 0; - pm->use_update_info = 0; - pm->interlace_type = PNG_INTERLACE_NONE; - pm->test_standard = 0; - pm->test_size = 0; - pm->test_transform = 0; - pm->use_input_precision = 0; - pm->use_input_precision_sbit = 0; - pm->use_input_precision_16to8 = 0; - pm->calculations_use_input_precision = 0; - pm->test_gamma_threshold = 0; - pm->test_gamma_transform = 0; - pm->test_gamma_sbit = 0; - pm->test_gamma_scale16 = 0; - pm->test_gamma_background = 0; - pm->test_gamma_alpha_mode = 0; - pm->test_gamma_expand16 = 0; - pm->test_exhaustive = 0; - pm->log = 0; - - /* Rely on the memset for all the other fields - there are no pointers */ -} - -#ifdef PNG_READ_TRANSFORMS_SUPPORTED -/* If pm->calculations_use_input_precision is set then operations will happen - * with only 8 bit precision unless both the input and output bit depth are 16. - * - * If pm->assume_16_bit_calculations is set then even 8 bit calculations use 16 - * bit precision. This only affects those of the following limits that pertain - * to a calculation - not a digitization operation - unless the following API is - * called directly. - */ -static double digitize(PNG_CONST png_modifier *pm, double value, - int sample_depth, int do_round) -{ - /* 'value' is in the range 0 to 1, the result is the same value rounded to a - * multiple of the digitization factor - 8 or 16 bits depending on both the - * sample depth and the 'assume' setting. Digitization is normally by - * rounding and 'do_round' should be 1, if it is 0 the digitized value will - * be truncated. - */ - PNG_CONST unsigned int digitization_factor = - (pm->assume_16_bit_calculations || sample_depth == 16) ? 65535 : 255; - - /* Limiting the range is done as a convenience to the caller - it's easier to - * do it once here than every time at the call site. - */ - if (value <= 0) - value = 0; - else if (value >= 1) - value = 1; - - value *= digitization_factor; - if (do_round) value += .5; - return floor(value)/digitization_factor; -} - -static double abserr(PNG_CONST png_modifier *pm, int in_depth, int out_depth) -{ - /* Absolute error permitted in linear values - affected by the bit depth of - * the calculations. - */ - if (pm->assume_16_bit_calculations || (out_depth == 16 && (in_depth == 16 || - !pm->calculations_use_input_precision))) - return pm->maxabs16; - else - return pm->maxabs8; -} - -static double calcerr(PNG_CONST png_modifier *pm, int in_depth, int out_depth) -{ - /* Error in the linear composition arithmetic - only relevant when - * composition actually happens (0 < alpha < 1). - */ - if (pm->assume_16_bit_calculations || (out_depth == 16 && (in_depth == 16 || - !pm->calculations_use_input_precision))) - return pm->maxcalc16; - else - return pm->maxcalc8; -} - -static double pcerr(PNG_CONST png_modifier *pm, int in_depth, int out_depth) -{ - /* Percentage error permitted in the linear values. Note that the specified - * value is a percentage but this routine returns a simple number. - */ - if (pm->assume_16_bit_calculations || (out_depth == 16 && (in_depth == 16 || - !pm->calculations_use_input_precision))) - return pm->maxpc16 * .01; - else - return pm->maxpc8 * .01; -} - -/* Output error - the error in the encoded value. This is determined by the - * digitization of the output so can be +/-0.5 in the actual output value. In - * the expand_16 case with the current code in libpng the expand happens after - * all the calculations are done in 8 bit arithmetic, so even though the output - * depth is 16 the output error is determined by the 8 bit calculation. - * - * This limit is not determined by the bit depth of internal calculations. - * - * The specified parameter does *not* include the base .5 digitization error but - * it is added here. - */ -static double outerr(PNG_CONST png_modifier *pm, int in_depth, int out_depth) -{ - /* There is a serious error in the 2 and 4 bit grayscale transform because - * the gamma table value (8 bits) is simply shifted, not rounded, so the - * error in 4 bit grayscale gamma is up to the value below. This is a hack - * to allow pngvalid to succeed: - * - * TODO: fix this in libpng - */ - if (out_depth == 2) - return .73182-.5; - - if (out_depth == 4) - return .90644-.5; - - if (out_depth == 16 && (in_depth == 16 || - !pm->calculations_use_input_precision)) - return pm->maxout16; - - /* This is the case where the value was calculated at 8-bit precision then - * scaled to 16 bits. - */ - else if (out_depth == 16) - return pm->maxout8 * 257; - - else - return pm->maxout8; -} - -/* This does the same thing as the above however it returns the value to log, - * rather than raising a warning. This is useful for debugging to track down - * exactly what set of parameters cause high error values. - */ -static double outlog(PNG_CONST png_modifier *pm, int in_depth, int out_depth) -{ - /* The command line parameters are either 8 bit (0..255) or 16 bit (0..65535) - * and so must be adjusted for low bit depth grayscale: - */ - if (out_depth <= 8) - { - if (pm->log8 == 0) /* switched off */ - return 256; - - if (out_depth < 8) - return pm->log8 / 255 * ((1<log8; - } - - if (out_depth == 16 && (in_depth == 16 || - !pm->calculations_use_input_precision)) - { - if (pm->log16 == 0) - return 65536; - - return pm->log16; - } - - /* This is the case where the value was calculated at 8-bit precision then - * scaled to 16 bits. - */ - if (pm->log8 == 0) - return 65536; - - return pm->log8 * 257; -} - -/* This complements the above by providing the appropriate quantization for the - * final value. Normally this would just be quantization to an integral value, - * but in the 8 bit calculation case it's actually quantization to a multiple of - * 257! - */ -static int output_quantization_factor(PNG_CONST png_modifier *pm, int in_depth, - int out_depth) -{ - if (out_depth == 16 && in_depth != 16 - && pm->calculations_use_input_precision) - return 257; - else - return 1; -} - -/* One modification structure must be provided for each chunk to be modified (in - * fact more than one can be provided if multiple separate changes are desired - * for a single chunk.) Modifications include adding a new chunk when a - * suitable chunk does not exist. - * - * The caller of modify_fn will reset the CRC of the chunk and record 'modified' - * or 'added' as appropriate if the modify_fn returns 1 (true). If the - * modify_fn is NULL the chunk is simply removed. - */ -typedef struct png_modification -{ - struct png_modification *next; - png_uint_32 chunk; - - /* If the following is NULL all matching chunks will be removed: */ - int (*modify_fn)(struct png_modifier *pm, - struct png_modification *me, int add); - - /* If the following is set to PLTE, IDAT or IEND and the chunk has not been - * found and modified (and there is a modify_fn) the modify_fn will be called - * to add the chunk before the relevant chunk. - */ - png_uint_32 add; - unsigned int modified :1; /* Chunk was modified */ - unsigned int added :1; /* Chunk was added */ - unsigned int removed :1; /* Chunk was removed */ -} png_modification; - -static void -modification_reset(png_modification *pmm) -{ - if (pmm != NULL) - { - pmm->modified = 0; - pmm->added = 0; - pmm->removed = 0; - modification_reset(pmm->next); - } -} - -static void -modification_init(png_modification *pmm) -{ - memset(pmm, 0, sizeof *pmm); - pmm->next = NULL; - pmm->chunk = 0; - pmm->modify_fn = NULL; - pmm->add = 0; - modification_reset(pmm); -} - -static void -modifier_current_encoding(PNG_CONST png_modifier *pm, color_encoding *ce) -{ - if (pm->current_encoding != 0) - *ce = *pm->current_encoding; - - else - memset(ce, 0, sizeof *ce); - - ce->gamma = pm->current_gamma; -} - -static size_t -safecat_current_encoding(char *buffer, size_t bufsize, size_t pos, - PNG_CONST png_modifier *pm) -{ - pos = safecat_color_encoding(buffer, bufsize, pos, pm->current_encoding, - pm->current_gamma); - - if (pm->encoding_ignored) - pos = safecat(buffer, bufsize, pos, "[overridden]"); - - return pos; -} - -/* Iterate through the usefully testable color encodings. An encoding is one - * of: - * - * 1) Nothing (no color space, no gamma). - * 2) Just a gamma value from the gamma array (including 1.0) - * 3) A color space from the encodings array with the corresponding gamma. - * 4) The same, but with gamma 1.0 (only really useful with 16 bit calculations) - * - * The iterator selects these in turn, the randomizer selects one at random, - * which is used depends on the setting of the 'test_exhaustive' flag. Notice - * that this function changes the colour space encoding so it must only be - * called on completion of the previous test. This is what 'modifier_reset' - * does, below. - * - * After the function has been called the 'repeat' flag will still be set; the - * caller of modifier_reset must reset it at the start of each run of the test! - */ -static unsigned int -modifier_total_encodings(PNG_CONST png_modifier *pm) -{ - return 1 + /* (1) nothing */ - pm->ngammas + /* (2) gamma values to test */ - pm->nencodings + /* (3) total number of encodings */ - /* The following test only works after the first time through the - * png_modifier code because 'bit_depth' is set when the IHDR is read. - * modifier_reset, below, preserves the setting until after it has called - * the iterate function (also below.) - * - * For this reason do not rely on this function outside a call to - * modifier_reset. - */ - ((pm->bit_depth == 16 || pm->assume_16_bit_calculations) ? - pm->nencodings : 0); /* (4) encodings with gamma == 1.0 */ -} - -static void -modifier_encoding_iterate(png_modifier *pm) -{ - if (!pm->repeat && /* Else something needs the current encoding again. */ - pm->test_uses_encoding) /* Some transform is encoding dependent */ - { - if (pm->test_exhaustive) - { - if (++pm->encoding_counter >= modifier_total_encodings(pm)) - pm->encoding_counter = 0; /* This will stop the repeat */ - } - - else - { - /* Not exhaustive - choose an encoding at random; generate a number in - * the range 1..(max-1), so the result is always non-zero: - */ - if (pm->encoding_counter == 0) - pm->encoding_counter = random_mod(modifier_total_encodings(pm)-1)+1; - else - pm->encoding_counter = 0; - } - - if (pm->encoding_counter > 0) - pm->repeat = 1; - } - - else if (!pm->repeat) - pm->encoding_counter = 0; -} - -static void -modifier_reset(png_modifier *pm) -{ - store_read_reset(&pm->this); - pm->limit = 4E-3; - pm->pending_len = pm->pending_chunk = 0; - pm->flush = pm->buffer_count = pm->buffer_position = 0; - pm->modifications = NULL; - pm->state = modifier_start; - modifier_encoding_iterate(pm); - /* The following must be set in the next run. In particular - * test_uses_encodings must be set in the _ini function of each transform - * that looks at the encodings. (Not the 'add' function!) - */ - pm->test_uses_encoding = 0; - pm->current_gamma = 0; - pm->current_encoding = 0; - pm->encoding_ignored = 0; - /* These only become value after IHDR is read: */ - pm->bit_depth = pm->colour_type = 0; -} - -/* The following must be called before anything else to get the encoding set up - * on the modifier. In particular it must be called before the transform init - * functions are called. - */ -static void -modifier_set_encoding(png_modifier *pm) -{ - /* Set the encoding to the one specified by the current encoding counter, - * first clear out all the settings - this corresponds to an encoding_counter - * of 0. - */ - pm->current_gamma = 0; - pm->current_encoding = 0; - pm->encoding_ignored = 0; /* not ignored yet - happens in _ini functions. */ - - /* Now, if required, set the gamma and encoding fields. */ - if (pm->encoding_counter > 0) - { - /* The gammas[] array is an array of screen gammas, not encoding gammas, - * so we need the inverse: - */ - if (pm->encoding_counter <= pm->ngammas) - pm->current_gamma = 1/pm->gammas[pm->encoding_counter-1]; - - else - { - unsigned int i = pm->encoding_counter - pm->ngammas; - - if (i >= pm->nencodings) - { - i %= pm->nencodings; - pm->current_gamma = 1; /* Linear, only in the 16 bit case */ - } - - else - pm->current_gamma = pm->encodings[i].gamma; - - pm->current_encoding = pm->encodings + i; - } - } -} - -/* Enquiry functions to find out what is set. Notice that there is an implicit - * assumption below that the first encoding in the list is the one for sRGB. - */ -static int -modifier_color_encoding_is_sRGB(PNG_CONST png_modifier *pm) -{ - return pm->current_encoding != 0 && pm->current_encoding == pm->encodings && - pm->current_encoding->gamma == pm->current_gamma; -} - -static int -modifier_color_encoding_is_set(PNG_CONST png_modifier *pm) -{ - return pm->current_gamma != 0; -} - -/* Convenience macros. */ -#define CHUNK(a,b,c,d) (((a)<<24)+((b)<<16)+((c)<<8)+(d)) -#define CHUNK_IHDR CHUNK(73,72,68,82) -#define CHUNK_PLTE CHUNK(80,76,84,69) -#define CHUNK_IDAT CHUNK(73,68,65,84) -#define CHUNK_IEND CHUNK(73,69,78,68) -#define CHUNK_cHRM CHUNK(99,72,82,77) -#define CHUNK_gAMA CHUNK(103,65,77,65) -#define CHUNK_sBIT CHUNK(115,66,73,84) -#define CHUNK_sRGB CHUNK(115,82,71,66) - -/* The guts of modification are performed during a read. */ -static void -modifier_crc(png_bytep buffer) -{ - /* Recalculate the chunk CRC - a complete chunk must be in - * the buffer, at the start. - */ - uInt datalen = png_get_uint_32(buffer); - uLong crc = crc32(0, buffer+4, datalen+4); - /* The cast to png_uint_32 is safe because a crc32 is always a 32 bit value. - */ - png_save_uint_32(buffer+datalen+8, (png_uint_32)crc); -} - -static void -modifier_setbuffer(png_modifier *pm) -{ - modifier_crc(pm->buffer); - pm->buffer_count = png_get_uint_32(pm->buffer)+12; - pm->buffer_position = 0; -} - -/* Separate the callback into the actual implementation (which is passed the - * png_modifier explicitly) and the callback, which gets the modifier from the - * png_struct. - */ -static void -modifier_read_imp(png_modifier *pm, png_bytep pb, png_size_t st) -{ - while (st > 0) - { - size_t cb; - png_uint_32 len, chunk; - png_modification *mod; - - if (pm->buffer_position >= pm->buffer_count) switch (pm->state) - { - static png_byte sign[8] = { 137, 80, 78, 71, 13, 10, 26, 10 }; - case modifier_start: - store_read_imp(&pm->this, pm->buffer, 8); /* size of signature. */ - pm->buffer_count = 8; - pm->buffer_position = 0; - - if (memcmp(pm->buffer, sign, 8) != 0) - png_error(pm->this.pread, "invalid PNG file signature"); - pm->state = modifier_signature; - break; - - case modifier_signature: - store_read_imp(&pm->this, pm->buffer, 13+12); /* size of IHDR */ - pm->buffer_count = 13+12; - pm->buffer_position = 0; - - if (png_get_uint_32(pm->buffer) != 13 || - png_get_uint_32(pm->buffer+4) != CHUNK_IHDR) - png_error(pm->this.pread, "invalid IHDR"); - - /* Check the list of modifiers for modifications to the IHDR. */ - mod = pm->modifications; - while (mod != NULL) - { - if (mod->chunk == CHUNK_IHDR && mod->modify_fn && - (*mod->modify_fn)(pm, mod, 0)) - { - mod->modified = 1; - modifier_setbuffer(pm); - } - - /* Ignore removal or add if IHDR! */ - mod = mod->next; - } - - /* Cache information from the IHDR (the modified one.) */ - pm->bit_depth = pm->buffer[8+8]; - pm->colour_type = pm->buffer[8+8+1]; - - pm->state = modifier_IHDR; - pm->flush = 0; - break; - - case modifier_IHDR: - default: - /* Read a new chunk and process it until we see PLTE, IDAT or - * IEND. 'flush' indicates that there is still some data to - * output from the preceding chunk. - */ - if ((cb = pm->flush) > 0) - { - if (cb > st) cb = st; - pm->flush -= cb; - store_read_imp(&pm->this, pb, cb); - pb += cb; - st -= cb; - if (st == 0) return; - } - - /* No more bytes to flush, read a header, or handle a pending - * chunk. - */ - if (pm->pending_chunk != 0) - { - png_save_uint_32(pm->buffer, pm->pending_len); - png_save_uint_32(pm->buffer+4, pm->pending_chunk); - pm->pending_len = 0; - pm->pending_chunk = 0; - } - else - store_read_imp(&pm->this, pm->buffer, 8); - - pm->buffer_count = 8; - pm->buffer_position = 0; - - /* Check for something to modify or a terminator chunk. */ - len = png_get_uint_32(pm->buffer); - chunk = png_get_uint_32(pm->buffer+4); - - /* Terminators first, they may have to be delayed for added - * chunks - */ - if (chunk == CHUNK_PLTE || chunk == CHUNK_IDAT || - chunk == CHUNK_IEND) - { - mod = pm->modifications; - - while (mod != NULL) - { - if ((mod->add == chunk || - (mod->add == CHUNK_PLTE && chunk == CHUNK_IDAT)) && - mod->modify_fn != NULL && !mod->modified && !mod->added) - { - /* Regardless of what the modify function does do not run - * this again. - */ - mod->added = 1; - - if ((*mod->modify_fn)(pm, mod, 1 /*add*/)) - { - /* Reset the CRC on a new chunk */ - if (pm->buffer_count > 0) - modifier_setbuffer(pm); - - else - { - pm->buffer_position = 0; - mod->removed = 1; - } - - /* The buffer has been filled with something (we assume) - * so output this. Pend the current chunk. - */ - pm->pending_len = len; - pm->pending_chunk = chunk; - break; /* out of while */ - } - } - - mod = mod->next; - } - - /* Don't do any further processing if the buffer was modified - - * otherwise the code will end up modifying a chunk that was - * just added. - */ - if (mod != NULL) - break; /* out of switch */ - } - - /* If we get to here then this chunk may need to be modified. To - * do this it must be less than 1024 bytes in total size, otherwise - * it just gets flushed. - */ - if (len+12 <= sizeof pm->buffer) - { - store_read_imp(&pm->this, pm->buffer+pm->buffer_count, - len+12-pm->buffer_count); - pm->buffer_count = len+12; - - /* Check for a modification, else leave it be. */ - mod = pm->modifications; - while (mod != NULL) - { - if (mod->chunk == chunk) - { - if (mod->modify_fn == NULL) - { - /* Remove this chunk */ - pm->buffer_count = pm->buffer_position = 0; - mod->removed = 1; - break; /* Terminate the while loop */ - } - - else if ((*mod->modify_fn)(pm, mod, 0)) - { - mod->modified = 1; - /* The chunk may have been removed: */ - if (pm->buffer_count == 0) - { - pm->buffer_position = 0; - break; - } - modifier_setbuffer(pm); - } - } - - mod = mod->next; - } - } - - else - pm->flush = len+12 - pm->buffer_count; /* data + crc */ - - /* Take the data from the buffer (if there is any). */ - break; - } - - /* Here to read from the modifier buffer (not directly from - * the store, as in the flush case above.) - */ - cb = pm->buffer_count - pm->buffer_position; - - if (cb > st) - cb = st; - - memcpy(pb, pm->buffer + pm->buffer_position, cb); - st -= cb; - pb += cb; - pm->buffer_position += cb; - } -} - -/* The callback: */ -static void -modifier_read(png_structp pp, png_bytep pb, png_size_t st) -{ - png_modifier *pm = voidcast(png_modifier*, png_get_io_ptr(pp)); - - if (pm == NULL || pm->this.pread != pp) - png_error(pp, "bad modifier_read call"); - - modifier_read_imp(pm, pb, st); -} - -/* Like store_progressive_read but the data is getting changed as we go so we - * need a local buffer. - */ -static void -modifier_progressive_read(png_modifier *pm, png_structp pp, png_infop pi) -{ - if (pm->this.pread != pp || pm->this.current == NULL || - pm->this.next == NULL) - png_error(pp, "store state damaged (progressive)"); - - /* This is another Horowitz and Hill random noise generator. In this case - * the aim is to stress the progressive reader with truly horrible variable - * buffer sizes in the range 1..500, so a sequence of 9 bit random numbers - * is generated. We could probably just count from 1 to 32767 and get as - * good a result. - */ - for (;;) - { - static png_uint_32 noise = 1; - png_size_t cb, cbAvail; - png_byte buffer[512]; - - /* Generate 15 more bits of stuff: */ - noise = (noise << 9) | ((noise ^ (noise >> (9-5))) & 0x1ff); - cb = noise & 0x1ff; - - /* Check that this number of bytes are available (in the current buffer.) - * (This doesn't quite work - the modifier might delete a chunk; unlikely - * but possible, it doesn't happen at present because the modifier only - * adds chunks to standard images.) - */ - cbAvail = store_read_buffer_avail(&pm->this); - if (pm->buffer_count > pm->buffer_position) - cbAvail += pm->buffer_count - pm->buffer_position; - - if (cb > cbAvail) - { - /* Check for EOF: */ - if (cbAvail == 0) - break; - - cb = cbAvail; - } - - modifier_read_imp(pm, buffer, cb); - png_process_data(pp, pi, buffer, cb); - } - - /* Check the invariants at the end (if this fails it's a problem in this - * file!) - */ - if (pm->buffer_count > pm->buffer_position || - pm->this.next != &pm->this.current->data || - pm->this.readpos < pm->this.current->datacount) - png_error(pp, "progressive read implementation error"); -} - -/* Set up a modifier. */ -static png_structp -set_modifier_for_read(png_modifier *pm, png_infopp ppi, png_uint_32 id, - PNG_CONST char *name) -{ - /* Do this first so that the modifier fields are cleared even if an error - * happens allocating the png_struct. No allocation is done here so no - * cleanup is required. - */ - pm->state = modifier_start; - pm->bit_depth = 0; - pm->colour_type = 255; - - pm->pending_len = 0; - pm->pending_chunk = 0; - pm->flush = 0; - pm->buffer_count = 0; - pm->buffer_position = 0; - - return set_store_for_read(&pm->this, ppi, id, name); -} - - -/******************************** MODIFICATIONS *******************************/ -/* Standard modifications to add chunks. These do not require the _SUPPORTED - * macros because the chunks can be there regardless of whether this specific - * libpng supports them. - */ -typedef struct gama_modification -{ - png_modification this; - png_fixed_point gamma; -} gama_modification; - -static int -gama_modify(png_modifier *pm, png_modification *me, int add) -{ - UNUSED(add) - /* This simply dumps the given gamma value into the buffer. */ - png_save_uint_32(pm->buffer, 4); - png_save_uint_32(pm->buffer+4, CHUNK_gAMA); - png_save_uint_32(pm->buffer+8, ((gama_modification*)me)->gamma); - return 1; -} - -static void -gama_modification_init(gama_modification *me, png_modifier *pm, double gammad) -{ - double g; - - modification_init(&me->this); - me->this.chunk = CHUNK_gAMA; - me->this.modify_fn = gama_modify; - me->this.add = CHUNK_PLTE; - g = fix(gammad); - me->gamma = (png_fixed_point)g; - me->this.next = pm->modifications; - pm->modifications = &me->this; -} - -typedef struct chrm_modification -{ - png_modification this; - PNG_CONST color_encoding *encoding; - png_fixed_point wx, wy, rx, ry, gx, gy, bx, by; -} chrm_modification; - -static int -chrm_modify(png_modifier *pm, png_modification *me, int add) -{ - UNUSED(add) - /* As with gAMA this just adds the required cHRM chunk to the buffer. */ - png_save_uint_32(pm->buffer , 32); - png_save_uint_32(pm->buffer+ 4, CHUNK_cHRM); - png_save_uint_32(pm->buffer+ 8, ((chrm_modification*)me)->wx); - png_save_uint_32(pm->buffer+12, ((chrm_modification*)me)->wy); - png_save_uint_32(pm->buffer+16, ((chrm_modification*)me)->rx); - png_save_uint_32(pm->buffer+20, ((chrm_modification*)me)->ry); - png_save_uint_32(pm->buffer+24, ((chrm_modification*)me)->gx); - png_save_uint_32(pm->buffer+28, ((chrm_modification*)me)->gy); - png_save_uint_32(pm->buffer+32, ((chrm_modification*)me)->bx); - png_save_uint_32(pm->buffer+36, ((chrm_modification*)me)->by); - return 1; -} - -static void -chrm_modification_init(chrm_modification *me, png_modifier *pm, - PNG_CONST color_encoding *encoding) -{ - CIE_color white = white_point(encoding); - - /* Original end points: */ - me->encoding = encoding; - - /* Chromaticities (in fixed point): */ - me->wx = fix(chromaticity_x(white)); - me->wy = fix(chromaticity_y(white)); - - me->rx = fix(chromaticity_x(encoding->red)); - me->ry = fix(chromaticity_y(encoding->red)); - me->gx = fix(chromaticity_x(encoding->green)); - me->gy = fix(chromaticity_y(encoding->green)); - me->bx = fix(chromaticity_x(encoding->blue)); - me->by = fix(chromaticity_y(encoding->blue)); - - modification_init(&me->this); - me->this.chunk = CHUNK_cHRM; - me->this.modify_fn = chrm_modify; - me->this.add = CHUNK_PLTE; - me->this.next = pm->modifications; - pm->modifications = &me->this; -} - -typedef struct srgb_modification -{ - png_modification this; - png_byte intent; -} srgb_modification; - -static int -srgb_modify(png_modifier *pm, png_modification *me, int add) -{ - UNUSED(add) - /* As above, ignore add and just make a new chunk */ - png_save_uint_32(pm->buffer, 1); - png_save_uint_32(pm->buffer+4, CHUNK_sRGB); - pm->buffer[8] = ((srgb_modification*)me)->intent; - return 1; -} - -static void -srgb_modification_init(srgb_modification *me, png_modifier *pm, png_byte intent) -{ - modification_init(&me->this); - me->this.chunk = CHUNK_sBIT; - - if (intent <= 3) /* if valid, else *delete* sRGB chunks */ - { - me->this.modify_fn = srgb_modify; - me->this.add = CHUNK_PLTE; - me->intent = intent; - } - - else - { - me->this.modify_fn = 0; - me->this.add = 0; - me->intent = 0; - } - - me->this.next = pm->modifications; - pm->modifications = &me->this; -} - -typedef struct sbit_modification -{ - png_modification this; - png_byte sbit; -} sbit_modification; - -static int -sbit_modify(png_modifier *pm, png_modification *me, int add) -{ - png_byte sbit = ((sbit_modification*)me)->sbit; - if (pm->bit_depth > sbit) - { - int cb = 0; - switch (pm->colour_type) - { - case 0: - cb = 1; - break; - - case 2: - case 3: - cb = 3; - break; - - case 4: - cb = 2; - break; - - case 6: - cb = 4; - break; - - default: - png_error(pm->this.pread, - "unexpected colour type in sBIT modification"); - } - - png_save_uint_32(pm->buffer, cb); - png_save_uint_32(pm->buffer+4, CHUNK_sBIT); - - while (cb > 0) - (pm->buffer+8)[--cb] = sbit; - - return 1; - } - else if (!add) - { - /* Remove the sBIT chunk */ - pm->buffer_count = pm->buffer_position = 0; - return 1; - } - else - return 0; /* do nothing */ -} - -static void -sbit_modification_init(sbit_modification *me, png_modifier *pm, png_byte sbit) -{ - modification_init(&me->this); - me->this.chunk = CHUNK_sBIT; - me->this.modify_fn = sbit_modify; - me->this.add = CHUNK_PLTE; - me->sbit = sbit; - me->this.next = pm->modifications; - pm->modifications = &me->this; -} -#endif /* PNG_READ_TRANSFORMS_SUPPORTED */ - -/***************************** STANDARD PNG FILES *****************************/ -/* Standard files - write and save standard files. */ -/* There are two basic forms of standard images. Those which attempt to have - * all the possible pixel values (not possible for 16bpp images, but a range of - * values are produced) and those which have a range of image sizes. The former - * are used for testing transforms, in particular gamma correction and bit - * reduction and increase. The latter are reserved for testing the behavior of - * libpng with respect to 'odd' image sizes - particularly small images where - * rows become 1 byte and interlace passes disappear. - * - * The first, most useful, set are the 'transform' images, the second set of - * small images are the 'size' images. - * - * The transform files are constructed with rows which fit into a 1024 byte row - * buffer. This makes allocation easier below. Further regardless of the file - * format every row has 128 pixels (giving 1024 bytes for 64bpp formats). - * - * Files are stored with no gAMA or sBIT chunks, with a PLTE only when needed - * and with an ID derived from the colour type, bit depth and interlace type - * as above (FILEID). The width (128) and height (variable) are not stored in - * the FILEID - instead the fields are set to 0, indicating a transform file. - * - * The size files ar constructed with rows a maximum of 128 bytes wide, allowing - * a maximum width of 16 pixels (for the 64bpp case.) They also have a maximum - * height of 16 rows. The width and height are stored in the FILEID and, being - * non-zero, indicate a size file. - * - * For palette image (colour type 3) multiple transform images are stored with - * the same bit depth to allow testing of more colour combinations - - * particularly important for testing the gamma code because libpng uses a - * different code path for palette images. For size images a single palette is - * used. - */ - -/* Make a 'standard' palette. Because there are only 256 entries in a palette - * (maximum) this actually makes a random palette in the hope that enough tests - * will catch enough errors. (Note that the same palette isn't produced every - * time for the same test - it depends on what previous tests have been run - - * but a given set of arguments to pngvalid will always produce the same palette - * at the same test! This is why pseudo-random number generators are useful for - * testing.) - * - * The store must be open for write when this is called, otherwise an internal - * error will occur. This routine contains its own magic number seed, so the - * palettes generated don't change if there are intervening errors (changing the - * calls to the store_mark seed.) - */ -static store_palette_entry * -make_standard_palette(png_store* ps, int npalette, int do_tRNS) -{ - static png_uint_32 palette_seed[2] = { 0x87654321, 9 }; - - int i = 0; - png_byte values[256][4]; - - /* Always put in black and white plus the six primary and secondary colors. - */ - for (; i<8; ++i) - { - values[i][1] = (i&1) ? 255 : 0; - values[i][2] = (i&2) ? 255 : 0; - values[i][3] = (i&4) ? 255 : 0; - } - - /* Then add 62 grays (one quarter of the remaining 256 slots). */ - { - int j = 0; - png_byte random_bytes[4]; - png_byte need[256]; - - need[0] = 0; /*got black*/ - memset(need+1, 1, (sizeof need)-2); /*need these*/ - need[255] = 0; /*but not white*/ - - while (i<70) - { - png_byte b; - - if (j==0) - { - make_four_random_bytes(palette_seed, random_bytes); - j = 4; - } - - b = random_bytes[--j]; - if (need[b]) - { - values[i][1] = b; - values[i][2] = b; - values[i++][3] = b; - } - } - } - - /* Finally add 192 colors at random - don't worry about matches to things we - * already have, chance is less than 1/65536. Don't worry about grays, - * chance is the same, so we get a duplicate or extra gray less than 1 time - * in 170. - */ - for (; i<256; ++i) - make_four_random_bytes(palette_seed, values[i]); - - /* Fill in the alpha values in the first byte. Just use all possible values - * (0..255) in an apparently random order: - */ - { - store_palette_entry *palette; - png_byte selector[4]; - - make_four_random_bytes(palette_seed, selector); - - if (do_tRNS) - for (i=0; i<256; ++i) - values[i][0] = (png_byte)(i ^ selector[0]); - - else - for (i=0; i<256; ++i) - values[i][0] = 255; /* no transparency/tRNS chunk */ - - /* 'values' contains 256 ARGB values, but we only need 'npalette'. - * 'npalette' will always be a power of 2: 2, 4, 16 or 256. In the low - * bit depth cases select colors at random, else it is difficult to have - * a set of low bit depth palette test with any chance of a reasonable - * range of colors. Do this by randomly permuting values into the low - * 'npalette' entries using an XOR mask generated here. This also - * permutes the npalette == 256 case in a potentially useful way (there is - * no relationship between palette index and the color value therein!) - */ - palette = store_write_palette(ps, npalette); - - for (i=0; i 0) - png_set_tRNS(pp, pi, tRNS, j, 0/*color*/); - } -} - -/* The number of passes is related to the interlace type. There was no libpng - * API to determine this prior to 1.5, so we need an inquiry function: - */ -static int -npasses_from_interlace_type(png_structp pp, int interlace_type) -{ - switch (interlace_type) - { - default: - png_error(pp, "invalid interlace type"); - - case PNG_INTERLACE_NONE: - return 1; - - case PNG_INTERLACE_ADAM7: - return PNG_INTERLACE_ADAM7_PASSES; - } -} - -static unsigned int -bit_size(png_structp pp, png_byte colour_type, png_byte bit_depth) -{ - switch (colour_type) - { - default: png_error(pp, "invalid color type"); - - case 0: return bit_depth; - - case 2: return 3*bit_depth; - - case 3: return bit_depth; - - case 4: return 2*bit_depth; - - case 6: return 4*bit_depth; - } -} - -#define TRANSFORM_WIDTH 128U -#define TRANSFORM_ROWMAX (TRANSFORM_WIDTH*8U) -#define SIZE_ROWMAX (16*8U) /* 16 pixels, max 8 bytes each - 128 bytes */ -#define STANDARD_ROWMAX TRANSFORM_ROWMAX /* The larger of the two */ -#define SIZE_HEIGHTMAX 16 /* Maximum range of size images */ - -static size_t -transform_rowsize(png_structp pp, png_byte colour_type, png_byte bit_depth) -{ - return (TRANSFORM_WIDTH * bit_size(pp, colour_type, bit_depth)) / 8; -} - -/* transform_width(pp, colour_type, bit_depth) current returns the same number - * every time, so just use a macro: - */ -#define transform_width(pp, colour_type, bit_depth) TRANSFORM_WIDTH - -static png_uint_32 -transform_height(png_structp pp, png_byte colour_type, png_byte bit_depth) -{ - switch (bit_size(pp, colour_type, bit_depth)) - { - case 1: - case 2: - case 4: - return 1; /* Total of 128 pixels */ - - case 8: - return 2; /* Total of 256 pixels/bytes */ - - case 16: - return 512; /* Total of 65536 pixels */ - - case 24: - case 32: - return 512; /* 65536 pixels */ - - case 48: - case 64: - return 2048;/* 4 x 65536 pixels. */ -# define TRANSFORM_HEIGHTMAX 2048 - - default: - return 0; /* Error, will be caught later */ - } -} - -/* The following can only be defined here, now we have the definitions - * of the transform image sizes. - */ -static png_uint_32 -standard_width(png_structp pp, png_uint_32 id) -{ - png_uint_32 width = WIDTH_FROM_ID(id); - UNUSED(pp) - - if (width == 0) - width = transform_width(pp, COL_FROM_ID(id), DEPTH_FROM_ID(id)); - - return width; -} - -static png_uint_32 -standard_height(png_structp pp, png_uint_32 id) -{ - png_uint_32 height = HEIGHT_FROM_ID(id); - - if (height == 0) - height = transform_height(pp, COL_FROM_ID(id), DEPTH_FROM_ID(id)); - - return height; -} - -static png_uint_32 -standard_rowsize(png_structp pp, png_uint_32 id) -{ - png_uint_32 width = standard_width(pp, id); - - /* This won't overflow: */ - width *= bit_size(pp, COL_FROM_ID(id), DEPTH_FROM_ID(id)); - return (width + 7) / 8; -} - -static void -transform_row(png_structp pp, png_byte buffer[TRANSFORM_ROWMAX], - png_byte colour_type, png_byte bit_depth, png_uint_32 y) -{ - png_uint_32 v = y << 7; - png_uint_32 i = 0; - - switch (bit_size(pp, colour_type, bit_depth)) - { - case 1: - while (i<128/8) buffer[i] = v & 0xff, v += 17, ++i; - return; - - case 2: - while (i<128/4) buffer[i] = v & 0xff, v += 33, ++i; - return; - - case 4: - while (i<128/2) buffer[i] = v & 0xff, v += 65, ++i; - return; - - case 8: - /* 256 bytes total, 128 bytes in each row set as follows: */ - while (i<128) buffer[i] = v & 0xff, ++v, ++i; - return; - - case 16: - /* Generate all 65536 pixel values in order, which includes the 8 bit - * GA case as well as the 16 bit G case. - */ - while (i<128) - buffer[2*i] = (v>>8) & 0xff, buffer[2*i+1] = v & 0xff, ++v, ++i; - - return; - - case 24: - /* 65535 pixels, but rotate the values. */ - while (i<128) - { - /* Three bytes per pixel, r, g, b, make b by r^g */ - buffer[3*i+0] = (v >> 8) & 0xff; - buffer[3*i+1] = v & 0xff; - buffer[3*i+2] = ((v >> 8) ^ v) & 0xff; - ++v; - ++i; - } - - return; - - case 32: - /* 65535 pixels, r, g, b, a; just replicate */ - while (i<128) - { - buffer[4*i+0] = (v >> 8) & 0xff; - buffer[4*i+1] = v & 0xff; - buffer[4*i+2] = (v >> 8) & 0xff; - buffer[4*i+3] = v & 0xff; - ++v; - ++i; - } - - return; - - case 48: - /* y is maximum 2047, giving 4x65536 pixels, make 'r' increase by 1 at - * each pixel, g increase by 257 (0x101) and 'b' by 0x1111: - */ - while (i<128) - { - png_uint_32 t = v++; - buffer[6*i+0] = (t >> 8) & 0xff; - buffer[6*i+1] = t & 0xff; - t *= 257; - buffer[6*i+2] = (t >> 8) & 0xff; - buffer[6*i+3] = t & 0xff; - t *= 17; - buffer[6*i+4] = (t >> 8) & 0xff; - buffer[6*i+5] = t & 0xff; - ++i; - } - - return; - - case 64: - /* As above in the 32 bit case. */ - while (i<128) - { - png_uint_32 t = v++; - buffer[8*i+0] = (t >> 8) & 0xff; - buffer[8*i+1] = t & 0xff; - buffer[8*i+4] = (t >> 8) & 0xff; - buffer[8*i+5] = t & 0xff; - t *= 257; - buffer[8*i+2] = (t >> 8) & 0xff; - buffer[8*i+3] = t & 0xff; - buffer[8*i+6] = (t >> 8) & 0xff; - buffer[8*i+7] = t & 0xff; - ++i; - } - return; - - default: - break; - } - - png_error(pp, "internal error"); -} - -/* This is just to do the right cast - could be changed to a function to check - * 'bd' but there isn't much point. - */ -#define DEPTH(bd) ((png_byte)(1U << (bd))) - -/* Make a standardized image given a an image colour type, bit depth and - * interlace type. The standard images have a very restricted range of - * rows and heights and are used for testing transforms rather than image - * layout details. See make_size_images below for a way to make images - * that test odd sizes along with the libpng interlace handling. - */ -static void -make_transform_image(png_store* PNG_CONST ps, png_byte PNG_CONST colour_type, - png_byte PNG_CONST bit_depth, int palette_number, int interlace_type, - png_const_charp name) -{ - context(ps, fault); - - Try - { - png_infop pi; - png_structp pp = set_store_for_write(ps, &pi, name); - png_uint_32 h; - - /* In the event of a problem return control to the Catch statement below - * to do the clean up - it is not possible to 'return' directly from a Try - * block. - */ - if (pp == NULL) - Throw ps; - - h = transform_height(pp, colour_type, bit_depth); - - png_set_IHDR(pp, pi, transform_width(pp, colour_type, bit_depth), h, - bit_depth, colour_type, interlace_type, - PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE); - -#ifdef PNG_TEXT_SUPPORTED - { - static char key[] = "image name"; /* must be writeable */ - size_t pos; - png_text text; - char copy[FILE_NAME_SIZE]; - - /* Use a compressed text string to test the correct interaction of text - * compression and IDAT compression. - */ - text.compression = PNG_TEXT_COMPRESSION_zTXt; - text.key = key; - /* Yuck: the text must be writable! */ - pos = safecat(copy, sizeof copy, 0, ps->wname); - text.text = copy; - text.text_length = pos; - text.itxt_length = 0; - text.lang = 0; - text.lang_key = 0; - - png_set_text(pp, pi, &text, 1); - } -#endif - - if (colour_type == 3) /* palette */ - init_standard_palette(ps, pp, pi, 1U << bit_depth, 1/*do tRNS*/); - - png_write_info(pp, pi); - - if (png_get_rowbytes(pp, pi) != - transform_rowsize(pp, colour_type, bit_depth)) - png_error(pp, "row size incorrect"); - - else - { - /* Somewhat confusingly this must be called *after* png_write_info - * because if it is called before, the information in *pp has not been - * updated to reflect the interlaced image. - */ - int npasses = png_set_interlace_handling(pp); - int pass; - - if (npasses != npasses_from_interlace_type(pp, interlace_type)) - png_error(pp, "write: png_set_interlace_handling failed"); - - for (pass=0; passtest, sizeof ps->test, 0, "make standard images"); - - /* Use next_format to enumerate all the combinations we test, including - * generating multiple low bit depth palette images. - */ - while (next_format(&colour_type, &bit_depth, &palette_number)) - { - int interlace_type; - - for (interlace_type = PNG_INTERLACE_NONE; - interlace_type < PNG_INTERLACE_LAST; ++interlace_type) - { - char name[FILE_NAME_SIZE]; - - standard_name(name, sizeof name, 0, colour_type, bit_depth, - palette_number, interlace_type, 0, 0, 0); - make_transform_image(ps, colour_type, bit_depth, palette_number, - interlace_type, name); - } - } -} - -/* The following two routines use the PNG interlace support macros from - * png.h to interlace or deinterlace rows. - */ -static void -interlace_row(png_bytep buffer, png_const_bytep imageRow, - unsigned int pixel_size, png_uint_32 w, int pass) -{ - png_uint_32 xin, xout, xstep; - - /* Note that this can, trivially, be optimized to a memcpy on pass 7, the - * code is presented this way to make it easier to understand. In practice - * consult the code in the libpng source to see other ways of doing this. - */ - xin = PNG_PASS_START_COL(pass); - xstep = 1U<= 8) - *buffer++ = (png_byte)y++, bit_width -= 8; - - /* There may be up to 7 remaining bits, these go in the most significant - * bits of the byte. - */ - if (bit_width > 0) - { - png_uint_32 mask = (1U<<(8-bit_width))-1; - *buffer = (png_byte)((*buffer & mask) | (y & ~mask)); - } -} - -static void -make_size_image(png_store* PNG_CONST ps, png_byte PNG_CONST colour_type, - png_byte PNG_CONST bit_depth, int PNG_CONST interlace_type, - png_uint_32 PNG_CONST w, png_uint_32 PNG_CONST h, - int PNG_CONST do_interlace) -{ - context(ps, fault); - - Try - { - png_infop pi; - png_structp pp; - unsigned int pixel_size; - - /* Make a name and get an appropriate id for the store: */ - char name[FILE_NAME_SIZE]; - PNG_CONST png_uint_32 id = FILEID(colour_type, bit_depth, 0/*palette*/, - interlace_type, w, h, do_interlace); - - standard_name_from_id(name, sizeof name, 0, id); - pp = set_store_for_write(ps, &pi, name); - - /* In the event of a problem return control to the Catch statement below - * to do the clean up - it is not possible to 'return' directly from a Try - * block. - */ - if (pp == NULL) - Throw ps; - - png_set_IHDR(pp, pi, w, h, bit_depth, colour_type, interlace_type, - PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE); - - if (colour_type == 3) /* palette */ - init_standard_palette(ps, pp, pi, 1U << bit_depth, 0/*do tRNS*/); - - png_write_info(pp, pi); - - /* Calculate the bit size, divide by 8 to get the byte size - this won't - * overflow because we know the w values are all small enough even for - * a system where 'unsigned int' is only 16 bits. - */ - pixel_size = bit_size(pp, colour_type, bit_depth); - if (png_get_rowbytes(pp, pi) != ((w * pixel_size) + 7) / 8) - png_error(pp, "row size incorrect"); - - else - { - int npasses = npasses_from_interlace_type(pp, interlace_type); - png_uint_32 y; - int pass; - png_byte image[16][SIZE_ROWMAX]; - - /* To help consistent error detection make the parts of this buffer - * that aren't set below all '1': - */ - memset(image, 0xff, sizeof image); - - if (!do_interlace && npasses != png_set_interlace_handling(pp)) - png_error(pp, "write: png_set_interlace_handling failed"); - - /* Prepare the whole image first to avoid making it 7 times: */ - for (y=0; y 0) - { - /* Set to all 1's for error detection (libpng tends to - * set unset things to 0). - */ - memset(tempRow, 0xff, sizeof tempRow); - interlace_row(tempRow, row, pixel_size, w, pass); - row = tempRow; - } - else - continue; - } - - /* Only get to here if the row has some pixels in it. */ - png_write_row(pp, row); - } - } - } - - png_write_end(pp, pi); - - /* And store this under the appropriate id, then clean up. */ - store_storefile(ps, id); - - store_write_reset(ps); - } - - Catch(fault) - { - /* Use the png_store returned by the exception. This may help the compiler - * because 'ps' is not used in this branch of the setjmp. Note that fault - * and ps will always be the same value. - */ - store_write_reset(fault); - } -} - -static void -make_size(png_store* PNG_CONST ps, png_byte PNG_CONST colour_type, int bdlo, - int PNG_CONST bdhi) -{ - for (; bdlo <= bdhi; ++bdlo) - { - png_uint_32 width; - - for (width = 1; width <= 16; ++width) - { - png_uint_32 height; - - for (height = 1; height <= 16; ++height) - { - /* The four combinations of DIY interlace and interlace or not - - * no interlace + DIY should be identical to no interlace with - * libpng doing it. - */ - make_size_image(ps, colour_type, DEPTH(bdlo), PNG_INTERLACE_NONE, - width, height, 0); - make_size_image(ps, colour_type, DEPTH(bdlo), PNG_INTERLACE_NONE, - width, height, 1); - make_size_image(ps, colour_type, DEPTH(bdlo), PNG_INTERLACE_ADAM7, - width, height, 0); - make_size_image(ps, colour_type, DEPTH(bdlo), PNG_INTERLACE_ADAM7, - width, height, 1); - } - } - } -} - -static void -make_size_images(png_store *ps) -{ - /* This is in case of errors. */ - safecat(ps->test, sizeof ps->test, 0, "make size images"); - - /* Arguments are colour_type, low bit depth, high bit depth - */ - make_size(ps, 0, 0, WRITE_BDHI); - make_size(ps, 2, 3, WRITE_BDHI); - make_size(ps, 3, 0, 3 /*palette: max 8 bits*/); - make_size(ps, 4, 3, WRITE_BDHI); - make_size(ps, 6, 3, WRITE_BDHI); -} - -/* Return a row based on image id and 'y' for checking: */ -static void -standard_row(png_structp pp, png_byte std[STANDARD_ROWMAX], png_uint_32 id, - png_uint_32 y) -{ - if (WIDTH_FROM_ID(id) == 0) - transform_row(pp, std, COL_FROM_ID(id), DEPTH_FROM_ID(id), y); - else - size_row(std, WIDTH_FROM_ID(id) * bit_size(pp, COL_FROM_ID(id), - DEPTH_FROM_ID(id)), y); -} - -/* Tests - individual test cases */ -/* Like 'make_standard' but errors are deliberately introduced into the calls - * to ensure that they get detected - it should not be possible to write an - * invalid image with libpng! - */ -#ifdef PNG_WARNINGS_SUPPORTED -static void -sBIT0_error_fn(png_structp pp, png_infop pi) -{ - /* 0 is invalid... */ - png_color_8 bad; - bad.red = bad.green = bad.blue = bad.gray = bad.alpha = 0; - png_set_sBIT(pp, pi, &bad); -} - -static void -sBIT_error_fn(png_structp pp, png_infop pi) -{ - png_byte bit_depth; - png_color_8 bad; - - if (png_get_color_type(pp, pi) == PNG_COLOR_TYPE_PALETTE) - bit_depth = 8; - - else - bit_depth = png_get_bit_depth(pp, pi); - - /* Now we know the bit depth we can easily generate an invalid sBIT entry */ - bad.red = bad.green = bad.blue = bad.gray = bad.alpha = - (png_byte)(bit_depth+1); - png_set_sBIT(pp, pi, &bad); -} - -static PNG_CONST struct -{ - void (*fn)(png_structp, png_infop); - PNG_CONST char *msg; - unsigned int warning :1; /* the error is a warning... */ -} error_test[] = - { - /* no warnings makes these errors undetectable. */ - { sBIT0_error_fn, "sBIT(0): failed to detect error", 1 }, - { sBIT_error_fn, "sBIT(too big): failed to detect error", 1 }, - }; - -static void -make_error(png_store* volatile ps, png_byte PNG_CONST colour_type, - png_byte bit_depth, int interlace_type, int test, png_const_charp name) -{ - context(ps, fault); - - Try - { - png_structp pp; - png_infop pi; - - pp = set_store_for_write(ps, &pi, name); - - if (pp == NULL) - Throw ps; - - png_set_IHDR(pp, pi, transform_width(pp, colour_type, bit_depth), - transform_height(pp, colour_type, bit_depth), bit_depth, colour_type, - interlace_type, PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE); - - if (colour_type == 3) /* palette */ - init_standard_palette(ps, pp, pi, 1U << bit_depth, 0/*do tRNS*/); - - /* Time for a few errors; these are in various optional chunks, the - * standard tests test the standard chunks pretty well. - */ -# define exception__prev exception_prev_1 -# define exception__env exception_env_1 - Try - { - /* Expect this to throw: */ - ps->expect_error = !error_test[test].warning; - ps->expect_warning = error_test[test].warning; - ps->saw_warning = 0; - error_test[test].fn(pp, pi); - - /* Normally the error is only detected here: */ - png_write_info(pp, pi); - - /* And handle the case where it was only a warning: */ - if (ps->expect_warning && ps->saw_warning) - Throw ps; - - /* If we get here there is a problem, we have success - no error or - * no warning - when we shouldn't have success. Log an error. - */ - store_log(ps, pp, error_test[test].msg, 1 /*error*/); - } - - Catch (fault) - ps = fault; /* expected exit, make sure ps is not clobbered */ -#undef exception__prev -#undef exception__env - - /* And clear these flags */ - ps->expect_error = 0; - ps->expect_warning = 0; - - /* Now write the whole image, just to make sure that the detected, or - * undetected, errro has not created problems inside libpng. - */ - if (png_get_rowbytes(pp, pi) != - transform_rowsize(pp, colour_type, bit_depth)) - png_error(pp, "row size incorrect"); - - else - { - png_uint_32 h = transform_height(pp, colour_type, bit_depth); - int npasses = png_set_interlace_handling(pp); - int pass; - - if (npasses != npasses_from_interlace_type(pp, interlace_type)) - png_error(pp, "write: png_set_interlace_handling failed"); - - for (pass=0; passthis, colour_type, DEPTH(bdlo), interlace_type, - test, name); - - if (fail(pm)) - return 0; - } - } - } - - return 1; /* keep going */ -} -#endif - -static void -perform_error_test(png_modifier *pm) -{ -#ifdef PNG_WARNINGS_SUPPORTED /* else there are no cases that work! */ - /* Need to do this here because we just write in this test. */ - safecat(pm->this.test, sizeof pm->this.test, 0, "error test"); - - if (!make_errors(pm, 0, 0, WRITE_BDHI)) - return; - - if (!make_errors(pm, 2, 3, WRITE_BDHI)) - return; - - if (!make_errors(pm, 3, 0, 3)) - return; - - if (!make_errors(pm, 4, 3, WRITE_BDHI)) - return; - - if (!make_errors(pm, 6, 3, WRITE_BDHI)) - return; -#else - UNUSED(pm) -#endif -} - -/* This is just to validate the internal PNG formatting code - if this fails - * then the warning messages the library outputs will probably be garbage. - */ -static void -perform_formatting_test(png_store *volatile ps) -{ -#ifdef PNG_TIME_RFC1123_SUPPORTED - /* The handle into the formatting code is the RFC1123 support; this test does - * nothing if that is compiled out. - */ - context(ps, fault); - - Try - { - png_const_charp correct = "29 Aug 2079 13:53:60 +0000"; - png_const_charp result; - png_structp pp; - png_time pt; - - pp = set_store_for_write(ps, NULL, "libpng formatting test"); - - if (pp == NULL) - Throw ps; - - - /* Arbitrary settings: */ - pt.year = 2079; - pt.month = 8; - pt.day = 29; - pt.hour = 13; - pt.minute = 53; - pt.second = 60; /* a leap second */ - - result = png_convert_to_rfc1123(pp, &pt); - - if (result == NULL) - png_error(pp, "png_convert_to_rfc1123 failed"); - - if (strcmp(result, correct) != 0) - { - size_t pos = 0; - char msg[128]; - - pos = safecat(msg, sizeof msg, pos, "png_convert_to_rfc1123("); - pos = safecat(msg, sizeof msg, pos, correct); - pos = safecat(msg, sizeof msg, pos, ") returned: '"); - pos = safecat(msg, sizeof msg, pos, result); - pos = safecat(msg, sizeof msg, pos, "'"); - - png_error(pp, msg); - } - - store_write_reset(ps); - } - - Catch(fault) - { - store_write_reset(fault); - } -#else - UNUSED(ps) -#endif -} - -/* Because we want to use the same code in both the progressive reader and the - * sequential reader it is necessary to deal with the fact that the progressive - * reader callbacks only have one parameter (png_get_progressive_ptr()), so this - * must contain all the test parameters and all the local variables directly - * accessible to the sequential reader implementation. - * - * The technique adopted is to reinvent part of what Dijkstra termed a - * 'display'; an array of pointers to the stack frames of enclosing functions so - * that a nested function definition can access the local (C auto) variables of - * the functions that contain its definition. In fact C provides the first - * pointer (the local variables - the stack frame pointer) and the last (the - * global variables - the BCPL global vector typically implemented as global - * addresses), this code requires one more pointer to make the display - the - * local variables (and function call parameters) of the function that actually - * invokes either the progressive or sequential reader. - * - * Perhaps confusingly this technique is confounded with classes - the - * 'standard_display' defined here is sub-classed as the 'gamma_display' below. - * A gamma_display is a standard_display, taking advantage of the ANSI-C - * requirement that the pointer to the first member of a structure must be the - * same as the pointer to the structure. This allows us to reuse standard_ - * functions in the gamma test code; something that could not be done with - * nested functions! - */ -typedef struct standard_display -{ - png_store* ps; /* Test parameters (passed to the function) */ - png_byte colour_type; - png_byte bit_depth; - png_byte red_sBIT; /* Input data sBIT values. */ - png_byte green_sBIT; - png_byte blue_sBIT; - png_byte alpha_sBIT; - int interlace_type; - png_uint_32 id; /* Calculated file ID */ - png_uint_32 w; /* Width of image */ - png_uint_32 h; /* Height of image */ - int npasses; /* Number of interlaced passes */ - png_uint_32 pixel_size; /* Width of one pixel in bits */ - png_uint_32 bit_width; /* Width of output row in bits */ - size_t cbRow; /* Bytes in a row of the output image */ - int do_interlace; /* Do interlacing internally */ - int is_transparent; /* Transparency information was present. */ - int speed; /* Doing a speed test */ - int use_update_info;/* Call update_info, not start_image */ - struct - { - png_uint_16 red; - png_uint_16 green; - png_uint_16 blue; - } transparent; /* The transparent color, if set. */ - int npalette; /* Number of entries in the palette. */ - store_palette - palette; -} standard_display; - -static void -standard_display_init(standard_display *dp, png_store* ps, png_uint_32 id, - int do_interlace, int use_update_info) -{ - memset(dp, 0, sizeof *dp); - - dp->ps = ps; - dp->colour_type = COL_FROM_ID(id); - dp->bit_depth = DEPTH_FROM_ID(id); - if (dp->colour_type == 3) - dp->red_sBIT = dp->blue_sBIT = dp->green_sBIT = dp->alpha_sBIT = 8; - else - dp->red_sBIT = dp->blue_sBIT = dp->green_sBIT = dp->alpha_sBIT = - dp->bit_depth; - dp->interlace_type = INTERLACE_FROM_ID(id); - dp->id = id; - /* All the rest are filled in after the read_info: */ - dp->w = 0; - dp->h = 0; - dp->npasses = 0; - dp->pixel_size = 0; - dp->bit_width = 0; - dp->cbRow = 0; - dp->do_interlace = do_interlace; - dp->is_transparent = 0; - dp->speed = ps->speed; - dp->use_update_info = use_update_info; - dp->npalette = 0; - /* Preset the transparent color to black: */ - memset(&dp->transparent, 0, sizeof dp->transparent); - /* Preset the palette to full intensity/opaque througout: */ - memset(dp->palette, 0xff, sizeof dp->palette); -} - -/* Initialize the palette fields - this must be done later because the palette - * comes from the particular png_store_file that is selected. - */ -static void -standard_palette_init(standard_display *dp) -{ - store_palette_entry *palette = store_current_palette(dp->ps, &dp->npalette); - - /* The remaining entries remain white/opaque. */ - if (dp->npalette > 0) - { - int i = dp->npalette; - memcpy(dp->palette, palette, i * sizeof *palette); - - /* Check for a non-opaque palette entry: */ - while (--i >= 0) - if (palette[i].alpha < 255) - break; - -# ifdef __GNUC__ - /* GCC can't handle the more obviously optimizable version. */ - if (i >= 0) - dp->is_transparent = 1; - else - dp->is_transparent = 0; -# else - dp->is_transparent = (i >= 0); -# endif - } -} - -/* Utility to read the palette from the PNG file and convert it into - * store_palette format. This returns 1 if there is any transparency in the - * palette (it does not check for a transparent colour in the non-palette case.) - */ -static int -read_palette(store_palette palette, int *npalette, png_structp pp, png_infop pi) -{ - png_colorp pal; - png_bytep trans_alpha; - int num; - - pal = 0; - *npalette = -1; - - if (png_get_PLTE(pp, pi, &pal, npalette) & PNG_INFO_PLTE) - { - int i = *npalette; - - if (i <= 0 || i > 256) - png_error(pp, "validate: invalid PLTE count"); - - while (--i >= 0) - { - palette[i].red = pal[i].red; - palette[i].green = pal[i].green; - palette[i].blue = pal[i].blue; - } - - /* Mark the remainder of the entries with a flag value (other than - * white/opaque which is the flag value stored above.) - */ - memset(palette + *npalette, 126, (256-*npalette) * sizeof *palette); - } - - else /* !png_get_PLTE */ - { - if (*npalette != (-1)) - png_error(pp, "validate: invalid PLTE result"); - /* But there is no palette, so record this: */ - *npalette = 0; - memset(palette, 113, sizeof palette); - } - - trans_alpha = 0; - num = 2; /* force error below */ - if ((png_get_tRNS(pp, pi, &trans_alpha, &num, 0) & PNG_INFO_tRNS) != 0 && - (trans_alpha != NULL || num != 1/*returns 1 for a transparent color*/) && - /* Oops, if a palette tRNS gets expanded png_read_update_info (at least so - * far as 1.5.4) does not remove the trans_alpha pointer, only num_trans, - * so in the above call we get a success, we get a pointer (who knows what - * to) and we get num_trans == 0: - */ - !(trans_alpha != NULL && num == 0)) /* TODO: fix this in libpng. */ - { - int i; - - /* Any of these are crash-worthy - given the implementation of - * png_get_tRNS up to 1.5 an app won't crash if it just checks the - * result above and fails to check that the variables it passed have - * actually been filled in! Note that if the app were to pass the - * last, png_color_16p, variable too it couldn't rely on this. - */ - if (trans_alpha == NULL || num <= 0 || num > 256 || num > *npalette) - png_error(pp, "validate: unexpected png_get_tRNS (palette) result"); - - for (i=0; iis_transparent) - png_error(pp, "validate: palette transparency changed"); - - if (npalette != dp->npalette) - { - size_t pos = 0; - char msg[64]; - - pos = safecat(msg, sizeof msg, pos, "validate: palette size changed: "); - pos = safecatn(msg, sizeof msg, pos, dp->npalette); - pos = safecat(msg, sizeof msg, pos, " -> "); - pos = safecatn(msg, sizeof msg, pos, npalette); - png_error(pp, msg); - } - - { - int i = npalette; /* npalette is aliased */ - - while (--i >= 0) - if (palette[i].red != dp->palette[i].red || - palette[i].green != dp->palette[i].green || - palette[i].blue != dp->palette[i].blue || - palette[i].alpha != dp->palette[i].alpha) - png_error(pp, "validate: PLTE or tRNS chunk changed"); - } -} - -/* By passing a 'standard_display' the progressive callbacks can be used - * directly by the sequential code, the functions suffixed "_imp" are the - * implementations, the functions without the suffix are the callbacks. - * - * The code for the info callback is split into two because this callback calls - * png_read_update_info or png_start_read_image and what gets called depends on - * whether the info needs updating (we want to test both calls in pngvalid.) - */ -static void -standard_info_part1(standard_display *dp, png_structp pp, png_infop pi) -{ - if (png_get_bit_depth(pp, pi) != dp->bit_depth) - png_error(pp, "validate: bit depth changed"); - - if (png_get_color_type(pp, pi) != dp->colour_type) - png_error(pp, "validate: color type changed"); - - if (png_get_filter_type(pp, pi) != PNG_FILTER_TYPE_BASE) - png_error(pp, "validate: filter type changed"); - - if (png_get_interlace_type(pp, pi) != dp->interlace_type) - png_error(pp, "validate: interlacing changed"); - - if (png_get_compression_type(pp, pi) != PNG_COMPRESSION_TYPE_BASE) - png_error(pp, "validate: compression type changed"); - - dp->w = png_get_image_width(pp, pi); - - if (dp->w != standard_width(pp, dp->id)) - png_error(pp, "validate: image width changed"); - - dp->h = png_get_image_height(pp, pi); - - if (dp->h != standard_height(pp, dp->id)) - png_error(pp, "validate: image height changed"); - - /* Record (but don't check at present) the input sBIT according to the colour - * type information. - */ - { - png_color_8p sBIT = 0; - - if (png_get_sBIT(pp, pi, &sBIT) & PNG_INFO_sBIT) - { - int sBIT_invalid = 0; - - if (sBIT == 0) - png_error(pp, "validate: unexpected png_get_sBIT result"); - - if (dp->colour_type & PNG_COLOR_MASK_COLOR) - { - if (sBIT->red == 0 || sBIT->red > dp->bit_depth) - sBIT_invalid = 1; - else - dp->red_sBIT = sBIT->red; - - if (sBIT->green == 0 || sBIT->green > dp->bit_depth) - sBIT_invalid = 1; - else - dp->green_sBIT = sBIT->green; - - if (sBIT->blue == 0 || sBIT->blue > dp->bit_depth) - sBIT_invalid = 1; - else - dp->blue_sBIT = sBIT->blue; - } - - else /* !COLOR */ - { - if (sBIT->gray == 0 || sBIT->gray > dp->bit_depth) - sBIT_invalid = 1; - else - dp->blue_sBIT = dp->green_sBIT = dp->red_sBIT = sBIT->gray; - } - - /* All 8 bits in tRNS for a palette image are significant - see the - * spec. - */ - if (dp->colour_type & PNG_COLOR_MASK_ALPHA) - { - if (sBIT->alpha == 0 || sBIT->alpha > dp->bit_depth) - sBIT_invalid = 1; - else - dp->alpha_sBIT = sBIT->alpha; - } - - if (sBIT_invalid) - png_error(pp, "validate: sBIT value out of range"); - } - } - - /* Important: this is validating the value *before* any transforms have been - * put in place. It doesn't matter for the standard tests, where there are - * no transforms, but it does for other tests where rowbytes may change after - * png_read_update_info. - */ - if (png_get_rowbytes(pp, pi) != standard_rowsize(pp, dp->id)) - png_error(pp, "validate: row size changed"); - - /* Validate the colour type 3 palette (this can be present on other color - * types.) - */ - standard_palette_validate(dp, pp, pi); - - /* In any case always check for a tranparent color (notice that the - * colour type 3 case must not give a successful return on the get_tRNS call - * with these arguments!) - */ - { - png_color_16p trans_color = 0; - - if (png_get_tRNS(pp, pi, 0, 0, &trans_color) & PNG_INFO_tRNS) - { - if (trans_color == 0) - png_error(pp, "validate: unexpected png_get_tRNS (color) result"); - - switch (dp->colour_type) - { - case 0: - dp->transparent.red = dp->transparent.green = dp->transparent.blue = - trans_color->gray; - dp->is_transparent = 1; - break; - - case 2: - dp->transparent.red = trans_color->red; - dp->transparent.green = trans_color->green; - dp->transparent.blue = trans_color->blue; - dp->is_transparent = 1; - break; - - case 3: - /* Not expected because it should result in the array case - * above. - */ - png_error(pp, "validate: unexpected png_get_tRNS result"); - break; - - default: - png_error(pp, "validate: invalid tRNS chunk with alpha image"); - } - } - } - - /* Read the number of passes - expected to match the value used when - * creating the image (interlaced or not). This has the side effect of - * turning on interlace handling (if do_interlace is not set.) - */ - dp->npasses = npasses_from_interlace_type(pp, dp->interlace_type); - if (!dp->do_interlace && dp->npasses != png_set_interlace_handling(pp)) - png_error(pp, "validate: file changed interlace type"); - - /* Caller calls png_read_update_info or png_start_read_image now, then calls - * part2. - */ -} - -/* This must be called *after* the png_read_update_info call to get the correct - * 'rowbytes' value, otherwise png_get_rowbytes will refer to the untransformed - * image. - */ -static void -standard_info_part2(standard_display *dp, png_structp pp, png_infop pi, - int nImages) -{ - /* Record cbRow now that it can be found. */ - dp->pixel_size = bit_size(pp, png_get_color_type(pp, pi), - png_get_bit_depth(pp, pi)); - dp->bit_width = png_get_image_width(pp, pi) * dp->pixel_size; - dp->cbRow = png_get_rowbytes(pp, pi); - - /* Validate the rowbytes here again. */ - if (dp->cbRow != (dp->bit_width+7)/8) - png_error(pp, "bad png_get_rowbytes calculation"); - - /* Then ensure there is enough space for the output image(s). */ - store_ensure_image(dp->ps, pp, nImages, dp->cbRow, dp->h); -} - -static void -standard_info_imp(standard_display *dp, png_structp pp, png_infop pi, - int nImages) -{ - /* Note that the validation routine has the side effect of turning on - * interlace handling in the subsequent code. - */ - standard_info_part1(dp, pp, pi); - - /* And the info callback has to call this (or png_read_update_info - see - * below in the png_modifier code for that variant. - */ - if (dp->use_update_info) - { - /* For debugging the effect of multiple calls: */ - int i = dp->use_update_info; - while (i-- > 0) - png_read_update_info(pp, pi); - } - - else - png_start_read_image(pp); - - /* Validate the height, width and rowbytes plus ensure that sufficient buffer - * exists for decoding the image. - */ - standard_info_part2(dp, pp, pi, nImages); -} - -static void -standard_info(png_structp pp, png_infop pi) -{ - standard_display *dp = voidcast(standard_display*, - png_get_progressive_ptr(pp)); - - /* Call with nImages==1 because the progressive reader can only produce one - * image. - */ - standard_info_imp(dp, pp, pi, 1 /*only one image*/); -} - -static void -progressive_row(png_structp pp, png_bytep new_row, png_uint_32 y, int pass) -{ - PNG_CONST standard_display *dp = voidcast(standard_display*, - png_get_progressive_ptr(pp)); - - /* When handling interlacing some rows will be absent in each pass, the - * callback still gets called, but with a NULL pointer. This is checked - * in the 'else' clause below. We need our own 'cbRow', but we can't call - * png_get_rowbytes because we got no info structure. - */ - if (new_row != NULL) - { - png_bytep row; - - /* In the case where the reader doesn't do the interlace it gives - * us the y in the sub-image: - */ - if (dp->do_interlace && dp->interlace_type == PNG_INTERLACE_ADAM7) - { -#ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED - /* Use this opportunity to validate the png 'current' APIs: */ - if (y != png_get_current_row_number(pp)) - png_error(pp, "png_get_current_row_number is broken"); - - if (pass != png_get_current_pass_number(pp)) - png_error(pp, "png_get_current_pass_number is broken"); -#endif - - y = PNG_ROW_FROM_PASS_ROW(y, pass); - } - - /* Validate this just in case. */ - if (y >= dp->h) - png_error(pp, "invalid y to progressive row callback"); - - row = store_image_row(dp->ps, pp, 0, y); - -#ifdef PNG_READ_INTERLACING_SUPPORTED - /* Combine the new row into the old: */ - if (dp->do_interlace) - { - if (dp->interlace_type == PNG_INTERLACE_ADAM7) - deinterlace_row(row, new_row, dp->pixel_size, dp->w, pass); - else - row_copy(row, new_row, dp->pixel_size * dp->w); - } - else - png_progressive_combine_row(pp, row, new_row); - } else if (dp->interlace_type == PNG_INTERLACE_ADAM7 && - PNG_ROW_IN_INTERLACE_PASS(y, pass) && - PNG_PASS_COLS(dp->w, pass) > 0) - png_error(pp, "missing row in progressive de-interlacing"); -#endif /* PNG_READ_INTERLACING_SUPPORTED */ -} - -static void -sequential_row(standard_display *dp, png_structp pp, png_infop pi, - PNG_CONST int iImage, PNG_CONST int iDisplay) -{ - PNG_CONST int npasses = dp->npasses; - PNG_CONST int do_interlace = dp->do_interlace && - dp->interlace_type == PNG_INTERLACE_ADAM7; - PNG_CONST png_uint_32 height = standard_height(pp, dp->id); - PNG_CONST png_uint_32 width = standard_width(pp, dp->id); - PNG_CONST png_store* ps = dp->ps; - int pass; - - for (pass=0; pass 0 && PNG_ROW_IN_INTERLACE_PASS(y, pass)) - { - /* Read the row into a pair of temporary buffers, then do the - * merge here into the output rows. - */ - png_byte row[STANDARD_ROWMAX], display[STANDARD_ROWMAX]; - - /* The following aids (to some extent) error detection - we can - * see where png_read_row wrote. Use opposite values in row and - * display to make this easier. Don't use 0xff (which is used in - * the image write code to fill unused bits) or 0 (which is a - * likely value to overwrite unused bits with). - */ - memset(row, 0xc5, sizeof row); - memset(display, 0x5c, sizeof display); - - png_read_row(pp, row, display); - - if (iImage >= 0) - deinterlace_row(store_image_row(ps, pp, iImage, y), row, - dp->pixel_size, dp->w, pass); - - if (iDisplay >= 0) - deinterlace_row(store_image_row(ps, pp, iDisplay, y), display, - dp->pixel_size, dp->w, pass); - } - } - else - png_read_row(pp, - iImage >= 0 ? store_image_row(ps, pp, iImage, y) : NULL, - iDisplay >= 0 ? store_image_row(ps, pp, iDisplay, y) : NULL); - } - } - - /* And finish the read operation (only really necessary if the caller wants - * to find additional data in png_info from chunks after the last IDAT.) - */ - png_read_end(pp, pi); -} - -static void -standard_row_validate(standard_display *dp, png_structp pp, - int iImage, int iDisplay, png_uint_32 y) -{ - int where; - png_byte std[STANDARD_ROWMAX]; - - /* The row must be pre-initialized to the magic number here for the size - * tests to pass: - */ - memset(std, 178, sizeof std); - standard_row(pp, std, dp->id, y); - - /* At the end both the 'row' and 'display' arrays should end up identical. - * In earlier passes 'row' will be partially filled in, with only the pixels - * that have been read so far, but 'display' will have those pixels - * replicated to fill the unread pixels while reading an interlaced image. -#if PNG_LIBPNG_VER < 10506 - * The side effect inside the libpng sequential reader is that the 'row' - * array retains the correct values for unwritten pixels within the row - * bytes, while the 'display' array gets bits off the end of the image (in - * the last byte) trashed. Unfortunately in the progressive reader the - * row bytes are always trashed, so we always do a pixel_cmp here even though - * a memcmp of all cbRow bytes will succeed for the sequential reader. -#endif - */ - if (iImage >= 0 && - (where = pixel_cmp(std, store_image_row(dp->ps, pp, iImage, y), - dp->bit_width)) != 0) - { - char msg[64]; - sprintf(msg, "PNG image row[%d][%d] changed from %.2x to %.2x", y, - where-1, std[where-1], - store_image_row(dp->ps, pp, iImage, y)[where-1]); - png_error(pp, msg); - } - -#if PNG_LIBPNG_VER < 10506 - /* In this case use pixel_cmp because we need to compare a partial - * byte at the end of the row if the row is not an exact multiple - * of 8 bits wide. (This is fixed in libpng-1.5.6 and pixel_cmp is - * changed to match!) - */ -#endif - if (iDisplay >= 0 && - (where = pixel_cmp(std, store_image_row(dp->ps, pp, iDisplay, y), - dp->bit_width)) != 0) - { - char msg[64]; - sprintf(msg, "display row[%d][%d] changed from %.2x to %.2x", y, - where-1, std[where-1], - store_image_row(dp->ps, pp, iDisplay, y)[where-1]); - png_error(pp, msg); - } -} - -static void -standard_image_validate(standard_display *dp, png_structp pp, int iImage, - int iDisplay) -{ - png_uint_32 y; - - if (iImage >= 0) - store_image_check(dp->ps, pp, iImage); - - if (iDisplay >= 0) - store_image_check(dp->ps, pp, iDisplay); - - for (y=0; yh; ++y) - standard_row_validate(dp, pp, iImage, iDisplay, y); - - /* This avoids false positives if the validation code is never called! */ - dp->ps->validated = 1; -} - -static void -standard_end(png_structp pp, png_infop pi) -{ - standard_display *dp = voidcast(standard_display*, - png_get_progressive_ptr(pp)); - - UNUSED(pi) - - /* Validate the image - progressive reading only produces one variant for - * interlaced images. - */ - standard_image_validate(dp, pp, 0, -1); -} - -/* A single test run checking the standard image to ensure it is not damaged. */ -static void -standard_test(png_store* PNG_CONST psIn, png_uint_32 PNG_CONST id, - int do_interlace, int use_update_info) -{ - standard_display d; - context(psIn, fault); - - /* Set up the display (stack frame) variables from the arguments to the - * function and initialize the locals that are filled in later. - */ - standard_display_init(&d, psIn, id, do_interlace, use_update_info); - - /* Everything is protected by a Try/Catch. The functions called also - * typically have local Try/Catch blocks. - */ - Try - { - png_structp pp; - png_infop pi; - - /* Get a png_struct for reading the image. This will throw an error if it - * fails, so we don't need to check the result. - */ - pp = set_store_for_read(d.ps, &pi, d.id, - d.do_interlace ? (d.ps->progressive ? - "pngvalid progressive deinterlacer" : - "pngvalid sequential deinterlacer") : (d.ps->progressive ? - "progressive reader" : "sequential reader")); - - /* Initialize the palette correctly from the png_store_file. */ - standard_palette_init(&d); - - /* Introduce the correct read function. */ - if (d.ps->progressive) - { - png_set_progressive_read_fn(pp, &d, standard_info, progressive_row, - standard_end); - - /* Now feed data into the reader until we reach the end: */ - store_progressive_read(d.ps, pp, pi); - } - else - { - /* Note that this takes the store, not the display. */ - png_set_read_fn(pp, d.ps, store_read); - - /* Check the header values: */ - png_read_info(pp, pi); - - /* The code tests both versions of the images that the sequential - * reader can produce. - */ - standard_info_imp(&d, pp, pi, 2 /*images*/); - - /* Need the total bytes in the image below; we can't get to this point - * unless the PNG file values have been checked against the expected - * values. - */ - { - sequential_row(&d, pp, pi, 0, 1); - - /* After the last pass loop over the rows again to check that the - * image is correct. - */ - if (!d.speed) - standard_image_validate(&d, pp, 0, 1); - else - d.ps->validated = 1; - } - } - - /* Check for validation. */ - if (!d.ps->validated) - png_error(pp, "image read failed silently"); - - /* Successful completion. */ - } - - Catch(fault) - d.ps = fault; /* make sure this hasn't been clobbered. */ - - /* In either case clean up the store. */ - store_read_reset(d.ps); -} - -static int -test_standard(png_modifier* PNG_CONST pm, png_byte PNG_CONST colour_type, - int bdlo, int PNG_CONST bdhi) -{ - for (; bdlo <= bdhi; ++bdlo) - { - int interlace_type; - - for (interlace_type = PNG_INTERLACE_NONE; - interlace_type < PNG_INTERLACE_LAST; ++interlace_type) - { - standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), 0/*palette*/, - interlace_type, 0, 0, 0), 0/*do_interlace*/, pm->use_update_info); - - if (fail(pm)) - return 0; - } - } - - return 1; /* keep going */ -} - -static void -perform_standard_test(png_modifier *pm) -{ - /* Test each colour type over the valid range of bit depths (expressed as - * log2(bit_depth) in turn, stop as soon as any error is detected. - */ - if (!test_standard(pm, 0, 0, READ_BDHI)) - return; - - if (!test_standard(pm, 2, 3, READ_BDHI)) - return; - - if (!test_standard(pm, 3, 0, 3)) - return; - - if (!test_standard(pm, 4, 3, READ_BDHI)) - return; - - if (!test_standard(pm, 6, 3, READ_BDHI)) - return; -} - - -/********************************** SIZE TESTS ********************************/ -static int -test_size(png_modifier* PNG_CONST pm, png_byte PNG_CONST colour_type, - int bdlo, int PNG_CONST bdhi) -{ - /* Run the tests on each combination. - * - * NOTE: on my 32 bit x86 each of the following blocks takes - * a total of 3.5 seconds if done across every combo of bit depth - * width and height. This is a waste of time in practice, hence the - * hinc and winc stuff: - */ - static PNG_CONST png_byte hinc[] = {1, 3, 11, 1, 5}; - static PNG_CONST png_byte winc[] = {1, 9, 5, 7, 1}; - for (; bdlo <= bdhi; ++bdlo) - { - png_uint_32 h, w; - - for (h=1; h<=16; h+=hinc[bdlo]) for (w=1; w<=16; w+=winc[bdlo]) - { - /* First test all the 'size' images against the sequential - * reader using libpng to deinterlace (where required.) This - * validates the write side of libpng. There are four possibilities - * to validate. - */ - standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), 0/*palette*/, - PNG_INTERLACE_NONE, w, h, 0), 0/*do_interlace*/, - pm->use_update_info); - - if (fail(pm)) - return 0; - - standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), 0/*palette*/, - PNG_INTERLACE_NONE, w, h, 1), 0/*do_interlace*/, - pm->use_update_info); - - if (fail(pm)) - return 0; - - standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), 0/*palette*/, - PNG_INTERLACE_ADAM7, w, h, 0), 0/*do_interlace*/, - pm->use_update_info); - - if (fail(pm)) - return 0; - - standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), 0/*palette*/, - PNG_INTERLACE_ADAM7, w, h, 1), 0/*do_interlace*/, - pm->use_update_info); - - if (fail(pm)) - return 0; - - /* Now validate the interlaced read side - do_interlace true, - * in the progressive case this does actually make a difference - * to the code used in the non-interlaced case too. - */ - standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), 0/*palette*/, - PNG_INTERLACE_NONE, w, h, 0), 1/*do_interlace*/, - pm->use_update_info); - - if (fail(pm)) - return 0; - - standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), 0/*palette*/, - PNG_INTERLACE_ADAM7, w, h, 0), 1/*do_interlace*/, - pm->use_update_info); - - if (fail(pm)) - return 0; - } - } - - return 1; /* keep going */ -} - -static void -perform_size_test(png_modifier *pm) -{ - /* Test each colour type over the valid range of bit depths (expressed as - * log2(bit_depth) in turn, stop as soon as any error is detected. - */ - if (!test_size(pm, 0, 0, READ_BDHI)) - return; - - if (!test_size(pm, 2, 3, READ_BDHI)) - return; - - /* For the moment don't do the palette test - it's a waste of time when - * compared to the grayscale test. - */ -#if 0 - if (!test_size(pm, 3, 0, 3)) - return; -#endif - - if (!test_size(pm, 4, 3, READ_BDHI)) - return; - - if (!test_size(pm, 6, 3, READ_BDHI)) - return; -} - - -/******************************* TRANSFORM TESTS ******************************/ -#ifdef PNG_READ_TRANSFORMS_SUPPORTED -/* A set of tests to validate libpng image transforms. The possibilities here - * are legion because the transforms can be combined in a combinatorial - * fashion. To deal with this some measure of restraint is required, otherwise - * the tests would take forever. - */ -typedef struct image_pixel -{ - /* A local (pngvalid) representation of a PNG pixel, in all its - * various forms. - */ - unsigned int red, green, blue, alpha; /* For non-palette images. */ - unsigned int palette_index; /* For a palette image. */ - png_byte colour_type; /* As in the spec. */ - png_byte bit_depth; /* Defines bit size in row */ - png_byte sample_depth; /* Scale of samples */ - int have_tRNS; /* tRNS chunk may need processing */ - - /* For checking the code calculates double precision floating point values - * along with an error value, accumulated from the transforms. Because an - * sBIT setting allows larger error bounds (indeed, by the spec, apparently - * up to just less than +/-1 in the scaled value) the *lowest* sBIT for each - * channel is stored. This sBIT value is folded in to the stored error value - * at the end of the application of the transforms to the pixel. - */ - double redf, greenf, bluef, alphaf; - double rede, greene, bluee, alphae; - png_byte red_sBIT, green_sBIT, blue_sBIT, alpha_sBIT; -} image_pixel; - -/* Shared utility function, see below. */ -static void -image_pixel_setf(image_pixel *this, unsigned int max) -{ - this->redf = this->red / (double)max; - this->greenf = this->green / (double)max; - this->bluef = this->blue / (double)max; - this->alphaf = this->alpha / (double)max; - - if (this->red < max) - this->rede = this->redf * DBL_EPSILON; - else - this->rede = 0; - if (this->green < max) - this->greene = this->greenf * DBL_EPSILON; - else - this->greene = 0; - if (this->blue < max) - this->bluee = this->bluef * DBL_EPSILON; - else - this->bluee = 0; - if (this->alpha < max) - this->alphae = this->alphaf * DBL_EPSILON; - else - this->alphae = 0; -} - -/* Initialize the structure for the next pixel - call this before doing any - * transforms and call it for each pixel since all the fields may need to be - * reset. - */ -static void -image_pixel_init(image_pixel *this, png_const_bytep row, png_byte colour_type, - png_byte bit_depth, png_uint_32 x, store_palette palette) -{ - PNG_CONST png_byte sample_depth = (png_byte)(colour_type == - PNG_COLOR_TYPE_PALETTE ? 8 : bit_depth); - PNG_CONST unsigned int max = (1U<palette_index = this->red = this->green = this->blue = - sample(row, colour_type, bit_depth, x, 0); - this->alpha = max; - this->red_sBIT = this->green_sBIT = this->blue_sBIT = this->alpha_sBIT = - sample_depth; - - /* Then override as appropriate: */ - if (colour_type == 3) /* palette */ - { - /* This permits the caller to default to the sample value. */ - if (palette != 0) - { - PNG_CONST unsigned int i = this->palette_index; - - this->red = palette[i].red; - this->green = palette[i].green; - this->blue = palette[i].blue; - this->alpha = palette[i].alpha; - } - } - - else /* not palette */ - { - unsigned int i = 0; - - if (colour_type & 2) - { - this->green = sample(row, colour_type, bit_depth, x, 1); - this->blue = sample(row, colour_type, bit_depth, x, 2); - i = 2; - } - if (colour_type & 4) - this->alpha = sample(row, colour_type, bit_depth, x, ++i); - } - - /* Calculate the scaled values, these are simply the values divided by - * 'max' and the error is initialized to the double precision epsilon value - * from the header file. - */ - image_pixel_setf(this, max); - - /* Store the input information for use in the transforms - these will - * modify the information. - */ - this->colour_type = colour_type; - this->bit_depth = bit_depth; - this->sample_depth = sample_depth; - this->have_tRNS = 0; -} - -/* Convert a palette image to an rgb image. This necessarily converts the tRNS - * chunk at the same time, because the tRNS will be in palette form. The way - * palette validation works means that the original palette is never updated, - * instead the image_pixel value from the row contains the RGB of the - * corresponding palette entry and *this* is updated. Consequently this routine - * only needs to change the colour type information. - */ -static void -image_pixel_convert_PLTE(image_pixel *this) -{ - if (this->colour_type == PNG_COLOR_TYPE_PALETTE) - { - if (this->have_tRNS) - { - this->colour_type = PNG_COLOR_TYPE_RGB_ALPHA; - this->have_tRNS = 0; - } - else - this->colour_type = PNG_COLOR_TYPE_RGB; - - /* The bit depth of the row changes at this point too (notice that this is - * the row format, not the sample depth, which is separate.) - */ - this->bit_depth = 8; - } -} - -/* Add an alpha channel; this will import the tRNS information because tRNS is - * not valid in an alpha image. The bit depth will invariably be set to at - * least 8. Palette images will be converted to alpha (using the above API). - */ -static void -image_pixel_add_alpha(image_pixel *this, PNG_CONST standard_display *display) -{ - if (this->colour_type == PNG_COLOR_TYPE_PALETTE) - image_pixel_convert_PLTE(this); - - if ((this->colour_type & PNG_COLOR_MASK_ALPHA) == 0) - { - if (this->colour_type == PNG_COLOR_TYPE_GRAY) - { - if (this->bit_depth < 8) - this->bit_depth = 8; - - if (this->have_tRNS) - { - this->have_tRNS = 0; - - /* Check the input, original, channel value here against the - * original tRNS gray chunk valie. - */ - if (this->red == display->transparent.red) - this->alphaf = 0; - else - this->alphaf = 1; - } - else - this->alphaf = 1; - - this->colour_type = PNG_COLOR_TYPE_GRAY_ALPHA; - } - - else if (this->colour_type == PNG_COLOR_TYPE_RGB) - { - if (this->have_tRNS) - { - this->have_tRNS = 0; - - /* Again, check the exact input values, not the current transformed - * value! - */ - if (this->red == display->transparent.red && - this->green == display->transparent.green && - this->blue == display->transparent.blue) - this->alphaf = 0; - else - this->alphaf = 1; - - this->colour_type = PNG_COLOR_TYPE_RGB_ALPHA; - } - } - - /* The error in the alpha is zero and the sBIT value comes from the - * original sBIT data (actually it will always be the original bit depth). - */ - this->alphae = 0; - this->alpha_sBIT = display->alpha_sBIT; - } -} - -struct transform_display; -typedef struct image_transform -{ - /* The name of this transform: a string. */ - PNG_CONST char *name; - - /* Each transform can be disabled from the command line: */ - int enable; - - /* The global list of transforms; read only. */ - struct image_transform *PNG_CONST list; - - /* The global count of the number of times this transform has been set on an - * image. - */ - unsigned int global_use; - - /* The local count of the number of times this transform has been set. */ - unsigned int local_use; - - /* The next transform in the list, each transform must call its own next - * transform after it has processed the pixel successfully. - */ - PNG_CONST struct image_transform *next; - - /* A single transform for the image, expressed as a series of function - * callbacks and some space for values. - * - * First a callback to add any required modifications to the png_modifier; - * this gets called just before the modifier is set up for read. - */ - void (*ini)(PNG_CONST struct image_transform *this, - struct transform_display *that); - - /* And a callback to set the transform on the current png_read_struct: - */ - void (*set)(PNG_CONST struct image_transform *this, - struct transform_display *that, png_structp pp, png_infop pi); - - /* Then a transform that takes an input pixel in one PNG format or another - * and modifies it by a pngvalid implementation of the transform (thus - * duplicating the libpng intent without, we hope, duplicating the bugs - * in the libpng implementation!) The png_structp is solely to allow error - * reporting via png_error and png_warning. - */ - void (*mod)(PNG_CONST struct image_transform *this, image_pixel *that, - png_structp pp, PNG_CONST struct transform_display *display); - - /* Add this transform to the list and return true if the transform is - * meaningful for this colour type and bit depth - if false then the - * transform should have no effect on the image so there's not a lot of - * point running it. - */ - int (*add)(struct image_transform *this, - PNG_CONST struct image_transform **that, png_byte colour_type, - png_byte bit_depth); -} image_transform; - -typedef struct transform_display -{ - standard_display this; - - /* Parameters */ - png_modifier* pm; - PNG_CONST image_transform* transform_list; - - /* Local variables */ - png_byte output_colour_type; - png_byte output_bit_depth; - - /* Modifications (not necessarily used.) */ - gama_modification gama_mod; - chrm_modification chrm_mod; - srgb_modification srgb_mod; -} transform_display; - -/* Set sRGB, cHRM and gAMA transforms as required by the current encoding. */ -static void -transform_set_encoding(transform_display *this) -{ - /* Set up the png_modifier '_current' fields then use these to determine how - * to add appropriate chunks. - */ - png_modifier *pm = this->pm; - - modifier_set_encoding(pm); - - if (modifier_color_encoding_is_set(pm)) - { - if (modifier_color_encoding_is_sRGB(pm)) - srgb_modification_init(&this->srgb_mod, pm, PNG_sRGB_INTENT_ABSOLUTE); - - else - { - /* Set gAMA and cHRM separately. */ - gama_modification_init(&this->gama_mod, pm, pm->current_gamma); - - if (pm->current_encoding != 0) - chrm_modification_init(&this->chrm_mod, pm, pm->current_encoding); - } - } -} - -/* Three functions to end the list: */ -static void -image_transform_ini_end(PNG_CONST image_transform *this, - transform_display *that) -{ - UNUSED(this) - UNUSED(that) -} - -static void -image_transform_set_end(PNG_CONST image_transform *this, - transform_display *that, png_structp pp, png_infop pi) -{ - UNUSED(this) - UNUSED(that) - UNUSED(pp) - UNUSED(pi) -} - -/* At the end of the list recalculate the output image pixel value from the - * double precision values set up by the preceding 'mod' calls: - */ -static unsigned int -sample_scale(double sample_value, unsigned int scale) -{ - sample_value = floor(sample_value * scale + .5); - - /* Return NaN as 0: */ - if (!(sample_value > 0)) - sample_value = 0; - else if (sample_value > scale) - sample_value = scale; - - return (unsigned int)sample_value; -} - -static void -image_transform_mod_end(PNG_CONST image_transform *this, image_pixel *that, - png_structp pp, PNG_CONST transform_display *display) -{ - PNG_CONST unsigned int scale = (1U<sample_depth)-1; - - UNUSED(this) - UNUSED(pp) - UNUSED(display) - - /* At the end recalculate the digitized red green and blue values according - * to the current sample_depth of the pixel. - * - * The sample value is simply scaled to the maximum, checking for over - * and underflow (which can both happen for some image transforms, - * including simple size scaling, though libpng doesn't do that at present. - */ - that->red = sample_scale(that->redf, scale); - - /* The error value is increased, at the end, according to the lowest sBIT - * value seen. Common sense tells us that the intermediate integer - * representations are no more accurate than +/- 0.5 in the integral values, - * the sBIT allows the implementation to be worse than this. In addition the - * PNG specification actually permits any error within the range (-1..+1), - * but that is ignored here. Instead the final digitized value is compared, - * below to the digitized value of the error limits - this has the net effect - * of allowing (almost) +/-1 in the output value. It's difficult to see how - * any algorithm that digitizes intermediate results can be more accurate. - */ - that->rede += 1./(2*((1U<red_sBIT)-1)); - - if (that->colour_type & PNG_COLOR_MASK_COLOR) - { - that->green = sample_scale(that->greenf, scale); - that->blue = sample_scale(that->bluef, scale); - that->greene += 1./(2*((1U<green_sBIT)-1)); - that->bluee += 1./(2*((1U<blue_sBIT)-1)); - } - else - { - that->blue = that->green = that->red; - that->bluef = that->greenf = that->redf; - that->bluee = that->greene = that->rede; - } - - if ((that->colour_type & PNG_COLOR_MASK_ALPHA) || - that->colour_type == PNG_COLOR_TYPE_PALETTE) - { - that->alpha = sample_scale(that->alphaf, scale); - that->alphae += 1./(2*((1U<alpha_sBIT)-1)); - } - else - { - that->alpha = scale; /* opaque */ - that->alpha = 1; /* Override this. */ - that->alphae = 0; /* It's exact ;-) */ - } -} - -/* Static 'end' structure: */ -static image_transform image_transform_end = -{ - "(end)", /* name */ - 1, /* enable */ - 0, /* list */ - 0, /* global_use */ - 0, /* local_use */ - 0, /* next */ - image_transform_ini_end, - image_transform_set_end, - image_transform_mod_end, - 0 /* never called, I want it to crash if it is! */ -}; - -/* Reader callbacks and implementations, where they differ from the standard - * ones. - */ -static void -transform_display_init(transform_display *dp, png_modifier *pm, png_uint_32 id, - PNG_CONST image_transform *transform_list) -{ - memset(dp, 0, sizeof dp); - - /* Standard fields */ - standard_display_init(&dp->this, &pm->this, id, 0/*do_interlace*/, - pm->use_update_info); - - /* Parameter fields */ - dp->pm = pm; - dp->transform_list = transform_list; - - /* Local variable fields */ - dp->output_colour_type = 255; /* invalid */ - dp->output_bit_depth = 255; /* invalid */ -} - -static void -transform_info_imp(transform_display *dp, png_structp pp, png_infop pi) -{ - /* Reuse the standard stuff as appropriate. */ - standard_info_part1(&dp->this, pp, pi); - - /* Now set the list of transforms. */ - dp->transform_list->set(dp->transform_list, dp, pp, pi); - - /* Update the info structure for these transforms: */ - { - int i = dp->this.use_update_info; - /* Always do one call, even if use_update_info is 0. */ - do - png_read_update_info(pp, pi); - while (--i > 0); - } - - /* And get the output information into the standard_display */ - standard_info_part2(&dp->this, pp, pi, 1/*images*/); - - /* Plus the extra stuff we need for the transform tests: */ - dp->output_colour_type = png_get_color_type(pp, pi); - dp->output_bit_depth = png_get_bit_depth(pp, pi); - - /* Validate the combination of colour type and bit depth that we are getting - * out of libpng; the semantics of something not in the PNG spec are, at - * best, unclear. - */ - switch (dp->output_colour_type) - { - case PNG_COLOR_TYPE_PALETTE: - if (dp->output_bit_depth > 8) goto error; - /*FALL THROUGH*/ - case PNG_COLOR_TYPE_GRAY: - if (dp->output_bit_depth == 1 || dp->output_bit_depth == 2 || - dp->output_bit_depth == 4) - break; - /*FALL THROUGH*/ - default: - if (dp->output_bit_depth == 8 || dp->output_bit_depth == 16) - break; - /*FALL THROUGH*/ - error: - { - char message[128]; - size_t pos; - - pos = safecat(message, sizeof message, 0, - "invalid final bit depth: colour type("); - pos = safecatn(message, sizeof message, pos, dp->output_colour_type); - pos = safecat(message, sizeof message, pos, ") with bit depth: "); - pos = safecatn(message, sizeof message, pos, dp->output_bit_depth); - - png_error(pp, message); - } - } - - /* Use a test pixel to check that the output agrees with what we expect - - * this avoids running the whole test if the output is unexpected. - */ - { - image_pixel test_pixel; - - memset(&test_pixel, 0, sizeof test_pixel); - test_pixel.colour_type = dp->this.colour_type; /* input */ - test_pixel.bit_depth = dp->this.bit_depth; - if (test_pixel.colour_type == PNG_COLOR_TYPE_PALETTE) - test_pixel.sample_depth = 8; - else - test_pixel.sample_depth = test_pixel.bit_depth; - /* Don't need sBIT here */ - test_pixel.have_tRNS = dp->this.is_transparent; - - dp->transform_list->mod(dp->transform_list, &test_pixel, pp, dp); - - if (test_pixel.colour_type != dp->output_colour_type) - { - char message[128]; - size_t pos = safecat(message, sizeof message, 0, "colour type "); - - pos = safecatn(message, sizeof message, pos, dp->output_colour_type); - pos = safecat(message, sizeof message, pos, " expected "); - pos = safecatn(message, sizeof message, pos, test_pixel.colour_type); - - png_error(pp, message); - } - - if (test_pixel.bit_depth != dp->output_bit_depth) - { - char message[128]; - size_t pos = safecat(message, sizeof message, 0, "bit depth "); - - pos = safecatn(message, sizeof message, pos, dp->output_bit_depth); - pos = safecat(message, sizeof message, pos, " expected "); - pos = safecatn(message, sizeof message, pos, test_pixel.bit_depth); - - png_error(pp, message); - } - - /* If both bit depth and colour type are correct check the sample depth. - * I believe these are both internal errors. - */ - if (test_pixel.colour_type == PNG_COLOR_TYPE_PALETTE) - { - if (test_pixel.sample_depth != 8) /* oops - internal error! */ - png_error(pp, "pngvalid: internal: palette sample depth not 8"); - } - else if (test_pixel.sample_depth != dp->output_bit_depth) - { - char message[128]; - size_t pos = safecat(message, sizeof message, 0, - "internal: sample depth "); - - pos = safecatn(message, sizeof message, pos, dp->output_bit_depth); - pos = safecat(message, sizeof message, pos, " expected "); - pos = safecatn(message, sizeof message, pos, test_pixel.sample_depth); - - png_error(pp, message); - } - } -} - -static void -transform_info(png_structp pp, png_infop pi) -{ - transform_info_imp(voidcast(transform_display*, png_get_progressive_ptr(pp)), - pp, pi); -} - -static void -transform_range_check(png_structp pp, unsigned int r, unsigned int g, - unsigned int b, unsigned int a, unsigned int in_digitized, double in, - unsigned int out, png_byte sample_depth, double err, double limit, - PNG_CONST char *name, double digitization_error) -{ - /* Compare the scaled, digitzed, values of our local calculation (in+-err) - * with the digitized values libpng produced; 'sample_depth' is the actual - * digitization depth of the libpng output colors (the bit depth except for - * palette images where it is always 8.) The check on 'err' is to detect - * internal errors in pngvalid itself. - */ - unsigned int max = (1U< limit || !(out >= in_min && out <= in_max)) - { - char message[256]; - size_t pos; - - pos = safecat(message, sizeof message, 0, name); - pos = safecat(message, sizeof message, pos, " output value error: rgba("); - pos = safecatn(message, sizeof message, pos, r); - pos = safecat(message, sizeof message, pos, ","); - pos = safecatn(message, sizeof message, pos, g); - pos = safecat(message, sizeof message, pos, ","); - pos = safecatn(message, sizeof message, pos, b); - pos = safecat(message, sizeof message, pos, ","); - pos = safecatn(message, sizeof message, pos, a); - pos = safecat(message, sizeof message, pos, "): "); - pos = safecatn(message, sizeof message, pos, out); - pos = safecat(message, sizeof message, pos, " expected: "); - pos = safecatn(message, sizeof message, pos, in_digitized); - pos = safecat(message, sizeof message, pos, " ("); - pos = safecatd(message, sizeof message, pos, (in-err)*max, 3); - pos = safecat(message, sizeof message, pos, ".."); - pos = safecatd(message, sizeof message, pos, (in+err)*max, 3); - pos = safecat(message, sizeof message, pos, ")"); - - png_error(pp, message); - } -} - -static void -transform_image_validate(transform_display *dp, png_structp pp, png_infop pi) -{ - /* Constants for the loop below: */ - PNG_CONST png_store* PNG_CONST ps = dp->this.ps; - PNG_CONST png_byte in_ct = dp->this.colour_type; - PNG_CONST png_byte in_bd = dp->this.bit_depth; - PNG_CONST png_uint_32 w = dp->this.w; - PNG_CONST png_uint_32 h = dp->this.h; - PNG_CONST png_byte out_ct = dp->output_colour_type; - PNG_CONST png_byte out_bd = dp->output_bit_depth; - PNG_CONST png_byte sample_depth = (png_byte)(out_ct == - PNG_COLOR_TYPE_PALETTE ? 8 : out_bd); - PNG_CONST png_byte red_sBIT = dp->this.red_sBIT; - PNG_CONST png_byte green_sBIT = dp->this.green_sBIT; - PNG_CONST png_byte blue_sBIT = dp->this.blue_sBIT; - PNG_CONST png_byte alpha_sBIT = dp->this.alpha_sBIT; - PNG_CONST int have_tRNS = dp->this.is_transparent; - double digitization_error; - - store_palette out_palette; - png_uint_32 y; - - UNUSED(pi) - - /* Check for row overwrite errors */ - store_image_check(dp->this.ps, pp, 0); - - /* Read the palette corresponding to the output if the output colour type - * indicates a palette, othewise set out_palette to garbage. - */ - if (out_ct == PNG_COLOR_TYPE_PALETTE) - { - /* Validate that the palette count itself has not changed - this is not - * expected. - */ - int npalette = (-1); - - (void)read_palette(out_palette, &npalette, pp, pi); - if (npalette != dp->this.npalette) - png_error(pp, "unexpected change in palette size"); - - digitization_error = .5; - } - else - { - png_byte in_sample_depth; - - memset(out_palette, 0x5e, sizeof out_palette); - - /* assume-8-bit-calculations means assume that if the input has 8 bit - * (or less) samples and the output has 16 bit samples the calculations - * will be done with 8 bit precision, not 16. - * - * TODO: fix this in libpng; png_set_expand_16 should cause 16 bit - * calculations to be used throughout. - */ - if (in_ct == PNG_COLOR_TYPE_PALETTE || in_bd < 16) - in_sample_depth = 8; - else - in_sample_depth = in_bd; - - if (sample_depth != 16 || in_sample_depth > 8 || - !dp->pm->calculations_use_input_precision) - digitization_error = .5; - - /* Else errors are at 8 bit precision, scale .5 in 8 bits to the 16 bits: - */ - else - digitization_error = .5 * 257; - } - - for (y=0; ythis.palette); - - in_pixel.red_sBIT = red_sBIT; - in_pixel.green_sBIT = green_sBIT; - in_pixel.blue_sBIT = blue_sBIT; - in_pixel.alpha_sBIT = alpha_sBIT; - in_pixel.have_tRNS = have_tRNS; - - /* For error detection, below. */ - r = in_pixel.red; - g = in_pixel.green; - b = in_pixel.blue; - a = in_pixel.alpha; - - dp->transform_list->mod(dp->transform_list, &in_pixel, pp, dp); - - /* Read the output pixel and compare it to what we got, we don't - * use the error field here, so no need to update sBIT. - */ - image_pixel_init(&out_pixel, pRow, out_ct, out_bd, x, out_palette); - - /* We don't expect changes to the index here even if the bit depth is - * changed. - */ - if (in_ct == PNG_COLOR_TYPE_PALETTE && - out_ct == PNG_COLOR_TYPE_PALETTE) - { - if (in_pixel.palette_index != out_pixel.palette_index) - png_error(pp, "unexpected transformed palette index"); - } - - /* Check the colours for palette images too - in fact the palette could - * be separately verified itself in most cases. - */ - if (in_pixel.red != out_pixel.red) - transform_range_check(pp, r, g, b, a, in_pixel.red, in_pixel.redf, - out_pixel.red, sample_depth, in_pixel.rede, - dp->pm->limit + 1./(2*((1U<pm->limit + 1./(2*((1U<pm->limit + 1./(2*((1U<pm->limit + 1./(2*((1U<this.ps->validated = 1; -} - -static void -transform_end(png_structp pp, png_infop pi) -{ - transform_display *dp = voidcast(transform_display*, - png_get_progressive_ptr(pp)); - - if (!dp->this.speed) - transform_image_validate(dp, pp, pi); - else - dp->this.ps->validated = 1; -} - -/* A single test run. */ -static void -transform_test(png_modifier *pmIn, PNG_CONST png_uint_32 idIn, - PNG_CONST image_transform* transform_listIn, PNG_CONST char * volatile name) -{ - transform_display d; - context(&pmIn->this, fault); - - transform_display_init(&d, pmIn, idIn, transform_listIn); - - Try - { - size_t pos = 0; - png_structp pp; - png_infop pi; - char full_name[256]; - - /* Make sure the encoding fields are correct and enter the required - * modifications. - */ - transform_set_encoding(&d); - - /* Add any modifications required by the transform list. */ - d.transform_list->ini(d.transform_list, &d); - - /* Add the color space information, if any, to the name. */ - pos = safecat(full_name, sizeof full_name, pos, name); - pos = safecat_current_encoding(full_name, sizeof full_name, pos, d.pm); - - /* Get a png_struct for reading the image. */ - pp = set_modifier_for_read(d.pm, &pi, d.this.id, full_name); - standard_palette_init(&d.this); - -# if 0 - /* Logging (debugging only) */ - { - char buffer[256]; - - (void)store_message(&d.pm->this, pp, buffer, sizeof buffer, 0, - "running test"); - - fprintf(stderr, "%s\n", buffer); - } -# endif - - /* Introduce the correct read function. */ - if (d.pm->this.progressive) - { - /* Share the row function with the standard implementation. */ - png_set_progressive_read_fn(pp, &d, transform_info, progressive_row, - transform_end); - - /* Now feed data into the reader until we reach the end: */ - modifier_progressive_read(d.pm, pp, pi); - } - else - { - /* modifier_read expects a png_modifier* */ - png_set_read_fn(pp, d.pm, modifier_read); - - /* Check the header values: */ - png_read_info(pp, pi); - - /* Process the 'info' requirements. Only one image is generated */ - transform_info_imp(&d, pp, pi); - - sequential_row(&d.this, pp, pi, -1, 0); - - if (!d.this.speed) - transform_image_validate(&d, pp, pi); - else - d.this.ps->validated = 1; - } - - modifier_reset(d.pm); - } - - Catch(fault) - { - modifier_reset((png_modifier*)fault); - } -} - -/* The transforms: */ -#define ITSTRUCT(name) image_transform_##name -#define ITDATA(name) image_transform_data_##name -#define image_transform_ini image_transform_default_ini -#define IT(name)\ -static image_transform ITSTRUCT(name) =\ -{\ - #name,\ - 1, /*enable*/\ - &PT, /*list*/\ - 0, /*global_use*/\ - 0, /*local_use*/\ - 0, /*next*/\ - image_transform_ini,\ - image_transform_png_set_##name##_set,\ - image_transform_png_set_##name##_mod,\ - image_transform_png_set_##name##_add\ -} -#define PT ITSTRUCT(end) /* stores the previous transform */ - -/* To save code: */ -static void -image_transform_default_ini(PNG_CONST image_transform *this, - transform_display *that) -{ - this->next->ini(this->next, that); -} - -static int -image_transform_default_add(image_transform *this, - PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) -{ - UNUSED(colour_type) - UNUSED(bit_depth) - - this->next = *that; - *that = this; - - return 1; -} - -#ifdef PNG_READ_EXPAND_SUPPORTED -/* png_set_palette_to_rgb */ -static void -image_transform_png_set_palette_to_rgb_set(PNG_CONST image_transform *this, - transform_display *that, png_structp pp, png_infop pi) -{ - png_set_palette_to_rgb(pp); - this->next->set(this->next, that, pp, pi); -} - -static void -image_transform_png_set_palette_to_rgb_mod(PNG_CONST image_transform *this, - image_pixel *that, png_structp pp, PNG_CONST transform_display *display) -{ - if (that->colour_type == PNG_COLOR_TYPE_PALETTE) - image_pixel_convert_PLTE(that); - - this->next->mod(this->next, that, pp, display); -} - -static int -image_transform_png_set_palette_to_rgb_add(image_transform *this, - PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) -{ - UNUSED(bit_depth) - - this->next = *that; - *that = this; - - return colour_type == PNG_COLOR_TYPE_PALETTE; -} - -IT(palette_to_rgb); -#undef PT -#define PT ITSTRUCT(palette_to_rgb) -#endif /* PNG_READ_EXPAND_SUPPORTED */ - -#ifdef PNG_READ_EXPAND_SUPPORTED -/* png_set_tRNS_to_alpha */ -static void -image_transform_png_set_tRNS_to_alpha_set(PNG_CONST image_transform *this, - transform_display *that, png_structp pp, png_infop pi) -{ - png_set_tRNS_to_alpha(pp); - this->next->set(this->next, that, pp, pi); -} - -static void -image_transform_png_set_tRNS_to_alpha_mod(PNG_CONST image_transform *this, - image_pixel *that, png_structp pp, PNG_CONST transform_display *display) -{ - /* LIBPNG BUG: this always forces palette images to RGB. */ - if (that->colour_type == PNG_COLOR_TYPE_PALETTE) - image_pixel_convert_PLTE(that); - - /* This effectively does an 'expand' only if there is some transparency to - * convert to an alpha channel. - */ - if (that->have_tRNS) - image_pixel_add_alpha(that, &display->this); - - /* LIBPNG BUG: otherwise libpng still expands to 8 bits! */ - else - { - if (that->bit_depth < 8) - that->bit_depth =8; - if (that->sample_depth < 8) - that->sample_depth = 8; - } - - this->next->mod(this->next, that, pp, display); -} - -static int -image_transform_png_set_tRNS_to_alpha_add(image_transform *this, - PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) -{ - UNUSED(bit_depth) - - this->next = *that; - *that = this; - - /* We don't know yet whether there will be a tRNS chunk, but we know that - * this transformation should do nothing if there already is an alpha - * channel. - */ - return (colour_type & PNG_COLOR_MASK_ALPHA) == 0; -} - -IT(tRNS_to_alpha); -#undef PT -#define PT ITSTRUCT(tRNS_to_alpha) -#endif /* PNG_READ_EXPAND_SUPPORTED */ - -#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED -/* png_set_gray_to_rgb */ -static void -image_transform_png_set_gray_to_rgb_set(PNG_CONST image_transform *this, - transform_display *that, png_structp pp, png_infop pi) -{ - png_set_gray_to_rgb(pp); - this->next->set(this->next, that, pp, pi); -} - -static void -image_transform_png_set_gray_to_rgb_mod(PNG_CONST image_transform *this, - image_pixel *that, png_structp pp, PNG_CONST transform_display *display) -{ - /* NOTE: we can actually pend the tRNS processing at this point because we - * can correctly recognize the original pixel value even though we have - * mapped the one gray channel to the three RGB ones, but in fact libpng - * doesn't do this, so we don't either. - */ - if ((that->colour_type & PNG_COLOR_MASK_COLOR) == 0 && that->have_tRNS) - image_pixel_add_alpha(that, &display->this); - - /* Simply expand the bit depth and alter the colour type as required. */ - if (that->colour_type == PNG_COLOR_TYPE_GRAY) - { - /* RGB images have a bit depth at least equal to '8' */ - if (that->bit_depth < 8) - that->sample_depth = that->bit_depth = 8; - - /* And just changing the colour type works here because the green and blue - * channels are being maintained in lock-step with the red/gray: - */ - that->colour_type = PNG_COLOR_TYPE_RGB; - } - - else if (that->colour_type == PNG_COLOR_TYPE_GRAY_ALPHA) - that->colour_type = PNG_COLOR_TYPE_RGB_ALPHA; - - this->next->mod(this->next, that, pp, display); -} - -static int -image_transform_png_set_gray_to_rgb_add(image_transform *this, - PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) -{ - UNUSED(bit_depth) - - this->next = *that; - *that = this; - - return (colour_type & PNG_COLOR_MASK_COLOR) == 0; -} - -IT(gray_to_rgb); -#undef PT -#define PT ITSTRUCT(gray_to_rgb) -#endif /* PNG_READ_GRAY_TO_RGB_SUPPORTED */ - -#ifdef PNG_READ_EXPAND_SUPPORTED -/* png_set_expand */ -static void -image_transform_png_set_expand_set(PNG_CONST image_transform *this, - transform_display *that, png_structp pp, png_infop pi) -{ - png_set_expand(pp); - this->next->set(this->next, that, pp, pi); -} - -static void -image_transform_png_set_expand_mod(PNG_CONST image_transform *this, - image_pixel *that, png_structp pp, PNG_CONST transform_display *display) -{ - /* The general expand case depends on what the colour type is: */ - if (that->colour_type == PNG_COLOR_TYPE_PALETTE) - image_pixel_convert_PLTE(that); - else if (that->bit_depth < 8) /* grayscale */ - that->sample_depth = that->bit_depth = 8; - - if (that->have_tRNS) - image_pixel_add_alpha(that, &display->this); - - this->next->mod(this->next, that, pp, display); -} - -static int -image_transform_png_set_expand_add(image_transform *this, - PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) -{ - UNUSED(bit_depth) - - this->next = *that; - *that = this; - - /* 'expand' should do nothing for RGBA or GA input - no tRNS and the bit - * depth is at least 8 already. - */ - return (colour_type & PNG_COLOR_MASK_ALPHA) == 0; -} - -IT(expand); -#undef PT -#define PT ITSTRUCT(expand) -#endif /* PNG_READ_EXPAND_SUPPORTED */ - -#ifdef PNG_READ_EXPAND_SUPPORTED -/* png_set_expand_gray_1_2_4_to_8 - * LIBPNG BUG: this just does an 'expand' - */ -static void -image_transform_png_set_expand_gray_1_2_4_to_8_set( - PNG_CONST image_transform *this, transform_display *that, png_structp pp, - png_infop pi) -{ - png_set_expand_gray_1_2_4_to_8(pp); - this->next->set(this->next, that, pp, pi); -} - -static void -image_transform_png_set_expand_gray_1_2_4_to_8_mod( - PNG_CONST image_transform *this, image_pixel *that, png_structp pp, - PNG_CONST transform_display *display) -{ - image_transform_png_set_expand_mod(this, that, pp, display); -} - -static int -image_transform_png_set_expand_gray_1_2_4_to_8_add(image_transform *this, - PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) -{ - return image_transform_png_set_expand_add(this, that, colour_type, - bit_depth); -} - -IT(expand_gray_1_2_4_to_8); -#undef PT -#define PT ITSTRUCT(expand_gray_1_2_4_to_8) -#endif /* PNG_READ_EXPAND_SUPPORTED */ - -#ifdef PNG_READ_EXPAND_16_SUPPORTED -/* png_set_expand_16 */ -static void -image_transform_png_set_expand_16_set(PNG_CONST image_transform *this, - transform_display *that, png_structp pp, png_infop pi) -{ - png_set_expand_16(pp); - this->next->set(this->next, that, pp, pi); -} - -static void -image_transform_png_set_expand_16_mod(PNG_CONST image_transform *this, - image_pixel *that, png_structp pp, PNG_CONST transform_display *display) -{ - /* Expect expand_16 to expand everything to 16 bits as a result of also - * causing 'expand' to happen. - */ - if (that->colour_type == PNG_COLOR_TYPE_PALETTE) - image_pixel_convert_PLTE(that); - - if (that->have_tRNS) - image_pixel_add_alpha(that, &display->this); - - if (that->bit_depth < 16) - that->sample_depth = that->bit_depth = 16; - - this->next->mod(this->next, that, pp, display); -} - -static int -image_transform_png_set_expand_16_add(image_transform *this, - PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) -{ - UNUSED(colour_type) - - this->next = *that; - *that = this; - - /* expand_16 does something unless the bit depth is already 16. */ - return bit_depth < 16; -} - -IT(expand_16); -#undef PT -#define PT ITSTRUCT(expand_16) -#endif /* PNG_READ_EXPAND_16_SUPPORTED */ - -#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED /* API added in 1.5.4 */ -/* png_set_scale_16 */ -static void -image_transform_png_set_scale_16_set(PNG_CONST image_transform *this, - transform_display *that, png_structp pp, png_infop pi) -{ - png_set_scale_16(pp); - this->next->set(this->next, that, pp, pi); -} - -static void -image_transform_png_set_scale_16_mod(PNG_CONST image_transform *this, - image_pixel *that, png_structp pp, PNG_CONST transform_display *display) -{ - if (that->bit_depth == 16) - { - that->sample_depth = that->bit_depth = 8; - if (that->red_sBIT > 8) that->red_sBIT = 8; - if (that->green_sBIT > 8) that->green_sBIT = 8; - if (that->blue_sBIT > 8) that->blue_sBIT = 8; - if (that->alpha_sBIT > 8) that->alpha_sBIT = 8; - } - - this->next->mod(this->next, that, pp, display); -} - -static int -image_transform_png_set_scale_16_add(image_transform *this, - PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) -{ - UNUSED(colour_type) - - this->next = *that; - *that = this; - - return bit_depth > 8; -} - -IT(scale_16); -#undef PT -#define PT ITSTRUCT(scale_16) -#endif /* PNG_READ_SCALE_16_TO_8_SUPPORTED (1.5.4 on) */ - -#ifdef PNG_READ_16_TO_8_SUPPORTED /* the default before 1.5.4 */ -/* png_set_strip_16 */ -static void -image_transform_png_set_strip_16_set(PNG_CONST image_transform *this, - transform_display *that, png_structp pp, png_infop pi) -{ - png_set_strip_16(pp); - this->next->set(this->next, that, pp, pi); -} - -static void -image_transform_png_set_strip_16_mod(PNG_CONST image_transform *this, - image_pixel *that, png_structp pp, PNG_CONST transform_display *display) -{ - if (that->bit_depth == 16) - { - that->sample_depth = that->bit_depth = 8; - if (that->red_sBIT > 8) that->red_sBIT = 8; - if (that->green_sBIT > 8) that->green_sBIT = 8; - if (that->blue_sBIT > 8) that->blue_sBIT = 8; - if (that->alpha_sBIT > 8) that->alpha_sBIT = 8; - - /* Prior to 1.5.4 png_set_strip_16 would use an 'accurate' method if this - * configuration option is set. From 1.5.4 the flag is never set and the - * 'scale' API (above) must be used. - */ -# ifdef PNG_READ_ACCURATE_SCALE_SUPPORTED -# if PNG_LIBPNG_VER >= 10504 -# error PNG_READ_ACCURATE_SCALE should not be set -# endif - - /* The strip 16 algorithm drops the low 8 bits rather than calculating - * 1/257, so we need to adjust the permitted errors appropriately: - * Notice that this is only relevant prior to the addition of the - * png_set_scale_16 API in 1.5.4 (but 1.5.4+ always defines the above!) - */ - { - PNG_CONST double d = (255-128.5)/65535; - that->rede += d; - that->greene += d; - that->bluee += d; - that->alphae += d; - } -# endif - } - - this->next->mod(this->next, that, pp, display); -} - -static int -image_transform_png_set_strip_16_add(image_transform *this, - PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) -{ - UNUSED(colour_type) - - this->next = *that; - *that = this; - - return bit_depth > 8; -} - -IT(strip_16); -#undef PT -#define PT ITSTRUCT(strip_16) -#endif /* PNG_READ_16_TO_8_SUPPORTED */ - -#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED -/* png_set_strip_alpha */ -static void -image_transform_png_set_strip_alpha_set(PNG_CONST image_transform *this, - transform_display *that, png_structp pp, png_infop pi) -{ - png_set_strip_alpha(pp); - this->next->set(this->next, that, pp, pi); -} - -static void -image_transform_png_set_strip_alpha_mod(PNG_CONST image_transform *this, - image_pixel *that, png_structp pp, PNG_CONST transform_display *display) -{ - if (that->colour_type == PNG_COLOR_TYPE_GRAY_ALPHA) - that->colour_type = PNG_COLOR_TYPE_GRAY; - else if (that->colour_type == PNG_COLOR_TYPE_RGB_ALPHA) - that->colour_type = PNG_COLOR_TYPE_RGB; - - that->have_tRNS = 0; - that->alphaf = 1; - - this->next->mod(this->next, that, pp, display); -} - -static int -image_transform_png_set_strip_alpha_add(image_transform *this, - PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) -{ - UNUSED(bit_depth) - - this->next = *that; - *that = this; - - return (colour_type & PNG_COLOR_MASK_ALPHA) != 0; -} - -IT(strip_alpha); -#undef PT -#define PT ITSTRUCT(strip_alpha) -#endif /* PNG_READ_STRIP_ALPHA_SUPPORTED */ - -#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED -/* png_set_rgb_to_gray(png_structp, int err_action, double red, double green) - * png_set_rgb_to_gray_fixed(png_structp, int err_action, png_fixed_point red, - * png_fixed_point green) - * png_get_rgb_to_gray_status - * - * The 'default' test here uses values known to be used inside libpng: - * - * red: 6968 - * green: 23434 - * blue: 2366 - * - * These values are being retained for compatibility, along with the somewhat - * broken truncation calculation in the fast-and-inaccurate code path. Older - * versions of libpng will fail the accuracy tests below because they use the - * truncation algorithm everywhere. - */ -#define data ITDATA(rgb_to_gray) -static struct -{ - double gamma; /* File gamma to use in processing */ - - /* The following are the parameters for png_set_rgb_to_gray: */ -# ifdef PNG_FLOATING_POINT_SUPPORTED - double red_to_set; - double green_to_set; -# else - png_fixed_point red_to_set; - png_fixed_point green_to_set; -# endif - - /* The actual coefficients: */ - double red_coefficient; - double green_coefficient; - double blue_coefficient; - - /* Set if the coeefficients have been overridden. */ - int coefficients_overridden; -} data; - -#undef image_transform_ini -#define image_transform_ini image_transform_png_set_rgb_to_gray_ini -static void -image_transform_png_set_rgb_to_gray_ini(PNG_CONST image_transform *this, - transform_display *that) -{ - png_modifier *pm = that->pm; - PNG_CONST color_encoding *e = pm->current_encoding; - - UNUSED(this) - - /* Since we check the encoding this flag must be set: */ - pm->test_uses_encoding = 1; - - /* If 'e' is not NULL chromaticity information is present and either a cHRM - * or an sRGB chunk will be inserted. - */ - if (e != 0) - { - /* Coefficients come from the encoding, but may need to be normalized to a - * white point Y of 1.0 - */ - PNG_CONST double whiteY = e->red.Y + e->green.Y + e->blue.Y; - - data.red_coefficient = e->red.Y; - data.green_coefficient = e->green.Y; - data.blue_coefficient = e->blue.Y; - - if (whiteY != 1) - { - data.red_coefficient /= whiteY; - data.green_coefficient /= whiteY; - data.blue_coefficient /= whiteY; - } - } - - else - { - /* The default (built in) coeffcients, as above: */ - data.red_coefficient = 6968 / 32768.; - data.green_coefficient = 23434 / 32768.; - data.blue_coefficient = 2366 / 32768.; - } - - data.gamma = pm->current_gamma; - - /* If not set then the calculations assume linear encoding (implicitly): */ - if (data.gamma == 0) - data.gamma = 1; - - /* The arguments to png_set_rgb_to_gray can override the coefficients implied - * by the color space encoding. If doing exhaustive checks do the override - * in each case, otherwise do it randomly. - */ - if (pm->test_exhaustive) - { - /* First time in coefficients_overridden is 0, the following sets it to 1, - * so repeat if it is set. If a test fails this may mean we subsequently - * skip a non-override test, ignore that. - */ - data.coefficients_overridden = !data.coefficients_overridden; - pm->repeat = data.coefficients_overridden != 0; - } - - else - data.coefficients_overridden = random_choice(); - - if (data.coefficients_overridden) - { - /* These values override the color encoding defaults, simply use random - * numbers. - */ - png_uint_32 ru; - double total; - - RANDOMIZE(ru); - data.green_coefficient = total = (ru & 0xffff) / 65535.; - ru >>= 16; - data.red_coefficient = (1 - total) * (ru & 0xffff) / 65535.; - total += data.red_coefficient; - data.blue_coefficient = 1 - total; - -# ifdef PNG_FLOATING_POINT_SUPPORTED - data.red_to_set = data.red_coefficient; - data.green_to_set = data.green_coefficient; -# else - data.red_to_set = fix(data.red_coefficient); - data.green_to_set = fix(data.green_coefficient); -# endif - - /* The following just changes the error messages: */ - pm->encoding_ignored = 1; - } - - else - { - data.red_to_set = -1; - data.green_to_set = -1; - } - - /* Adjust the error limit in the png_modifier because of the larger errors - * produced in the digitization during the gamma handling. - */ - if (data.gamma != 1) /* Use gamma tables */ - { - if (that->this.bit_depth == 16 || pm->assume_16_bit_calculations) - { - /* The 16 bit case ends up producing a maximum error of about - * +/-5 in 65535, allow for +/-8 with the given gamma. - */ - that->pm->limit += pow(8./65535, data.gamma); - } - - else - { - /* Rounding to 8 bits in the linear space causes massive errors which - * will trigger the error check in transform_range_check. Fix that - * here by taking the gamma encoding into account. - */ - that->pm->limit += pow(1./255, data.gamma); - } - } - - else - { - /* With no gamma correction a large error comes from the truncation of the - * calculation in the 8 bit case, allow for that here. - */ - if (that->this.bit_depth != 16) - that->pm->limit += 4E-3; - } -} - -static void -image_transform_png_set_rgb_to_gray_set(PNG_CONST image_transform *this, - transform_display *that, png_structp pp, png_infop pi) -{ - PNG_CONST int error_action = 1; /* no error, no defines in png.h */ - -# ifdef PNG_FLOATING_POINT_SUPPORTED - png_set_rgb_to_gray(pp, error_action, data.red_to_set, data.green_to_set); -# else - png_set_rgb_to_gray_fixed(pp, error_action, data.red_to_set, - data.green_to_set); -# endif - -# ifdef PNG_READ_cHRM_SUPPORTED - if (that->pm->current_encoding != 0) - { - /* We have an encoding so a cHRM chunk may have been set; if so then - * check that the libpng APIs give the correct (X,Y,Z) values within - * some margin of error for the round trip through the chromaticity - * form. - */ -# ifdef PNG_FLOATING_POINT_SUPPORTED -# define API_function png_get_cHRM_XYZ -# define API_form "FP" -# define API_type double -# define API_cvt(x) (x) -# else -# define API_function png_get_cHRM_XYZ_fixed -# define API_form "fixed" -# define API_type png_fixed_point -# define API_cvt(x) ((double)(x)/PNG_FP_1) -# endif - - API_type rX, gX, bX; - API_type rY, gY, bY; - API_type rZ, gZ, bZ; - - if ((API_function(pp, pi, &rX, &rY, &rZ, &gX, &gY, &gZ, &bX, &bY, &bZ) - & PNG_INFO_cHRM) != 0) - { - double maxe; - PNG_CONST char *el; - color_encoding e, o; - - /* Expect libpng to return a normalized result, but the original - * color space encoding may not be normalized. - */ - modifier_current_encoding(that->pm, &o); - normalize_color_encoding(&o); - - /* Sanity check the pngvalid code - the coefficients should match - * the normalized Y values of the encoding unless they were - * overridden. - */ - if (data.red_to_set == -1 && data.green_to_set == -1 && - (fabs(o.red.Y - data.red_coefficient) > DBL_EPSILON || - fabs(o.green.Y - data.green_coefficient) > DBL_EPSILON || - fabs(o.blue.Y - data.blue_coefficient) > DBL_EPSILON)) - png_error(pp, "internal pngvalid cHRM coefficient error"); - - /* Generate a colour space encoding. */ - e.gamma = o.gamma; /* not used */ - e.red.X = API_cvt(rX); - e.red.Y = API_cvt(rY); - e.red.Z = API_cvt(rZ); - e.green.X = API_cvt(gX); - e.green.Y = API_cvt(gY); - e.green.Z = API_cvt(gZ); - e.blue.X = API_cvt(bX); - e.blue.Y = API_cvt(bY); - e.blue.Z = API_cvt(bZ); - - /* This should match the original one from the png_modifier, within - * the range permitted by the libpng fixed point representation. - */ - maxe = 0; - el = "-"; /* Set to element name with error */ - -# define CHECK(col,x)\ - {\ - double err = fabs(o.col.x - e.col.x);\ - if (err > maxe)\ - {\ - maxe = err;\ - el = #col "(" #x ")";\ - }\ - } - - CHECK(red,X) - CHECK(red,Y) - CHECK(red,Z) - CHECK(green,X) - CHECK(green,Y) - CHECK(green,Z) - CHECK(blue,X) - CHECK(blue,Y) - CHECK(blue,Z) - - /* Here in both fixed and floating cases to check the values read - * from the cHRm chunk. PNG uses fixed point in the cHRM chunk, so - * we can't expect better than +/-.5E-5 on the result, allow 1E-5. - */ - if (maxe >= 1E-5) - { - size_t pos = 0; - char buffer[256]; - - pos = safecat(buffer, sizeof buffer, pos, API_form); - pos = safecat(buffer, sizeof buffer, pos, " cHRM "); - pos = safecat(buffer, sizeof buffer, pos, el); - pos = safecat(buffer, sizeof buffer, pos, " error: "); - pos = safecatd(buffer, sizeof buffer, pos, maxe, 7); - pos = safecat(buffer, sizeof buffer, pos, " "); - /* Print the color space without the gamma value: */ - pos = safecat_color_encoding(buffer, sizeof buffer, pos, &o, 0); - pos = safecat(buffer, sizeof buffer, pos, " -> "); - pos = safecat_color_encoding(buffer, sizeof buffer, pos, &e, 0); - - png_error(pp, buffer); - } - } - } -# endif /* READ_cHRM */ - - this->next->set(this->next, that, pp, pi); -} - -static void -image_transform_png_set_rgb_to_gray_mod(PNG_CONST image_transform *this, - image_pixel *that, png_structp pp, PNG_CONST transform_display *display) -{ - if ((that->colour_type & PNG_COLOR_MASK_COLOR) != 0) - { - double gray, err; - - if (that->colour_type == PNG_COLOR_TYPE_PALETTE) - image_pixel_convert_PLTE(that); - - /* Image now has RGB channels... */ - { - PNG_CONST png_modifier *pm = display->pm; - PNG_CONST unsigned int sample_depth = that->sample_depth; - int isgray; - double r, g, b; - double rlo, rhi, glo, ghi, blo, bhi, graylo, grayhi; - - /* Do this using interval arithmetic, otherwise it is too difficult to - * handle the errors correctly. - * - * To handle the gamma correction work out the upper and lower bounds - * of the digitized value. Assume rounding here - normally the values - * will be identical after this operation if there is only one - * transform, feel free to delete the png_error checks on this below in - * the future (this is just me trying to ensure it works!) - */ - r = rlo = rhi = that->redf; - rlo -= that->rede; - rlo = digitize(pm, rlo, sample_depth, 1/*round*/); - rhi += that->rede; - rhi = digitize(pm, rhi, sample_depth, 1/*round*/); - - g = glo = ghi = that->greenf; - glo -= that->greene; - glo = digitize(pm, glo, sample_depth, 1/*round*/); - ghi += that->greene; - ghi = digitize(pm, ghi, sample_depth, 1/*round*/); - - b = blo = bhi = that->bluef; - blo -= that->bluee; - blo = digitize(pm, blo, sample_depth, 1/*round*/); - bhi += that->greene; - bhi = digitize(pm, bhi, sample_depth, 1/*round*/); - - isgray = r==g && g==b; - - if (data.gamma != 1) - { - PNG_CONST double power = 1/data.gamma; - PNG_CONST double abse = abserr(pm, sample_depth, sample_depth); - - /* 'abse' is the absolute error permitted in linear calculations. It - * is used here to capture the error permitted in the handling - * (undoing) of the gamma encoding. Once again digitization occurs - * to handle the upper and lower bounds of the values. This is - * where the real errors are introduced. - */ - r = pow(r, power); - rlo = digitize(pm, pow(rlo, power)-abse, sample_depth, 1); - rhi = digitize(pm, pow(rhi, power)+abse, sample_depth, 1); - - g = pow(g, power); - glo = digitize(pm, pow(glo, power)-abse, sample_depth, 1); - ghi = digitize(pm, pow(ghi, power)+abse, sample_depth, 1); - - b = pow(b, power); - blo = digitize(pm, pow(blo, power)-abse, sample_depth, 1); - bhi = digitize(pm, pow(bhi, power)+abse, sample_depth, 1); - } - - /* Now calculate the actual gray values. Although the error in the - * coefficients depends on whether they were specified on the command - * line (in which case truncation to 15 bits happened) or not (rounding - * was used) the maxium error in an individual coefficient is always - * 1/32768, because even in the rounding case the requirement that - * coefficients add up to 32768 can cause a larger rounding error. - * - * The only time when rounding doesn't occur in 1.5.5 and later is when - * the non-gamma code path is used for less than 16 bit data. - */ - gray = r * data.red_coefficient + g * data.green_coefficient + - b * data.blue_coefficient; - - { - PNG_CONST int do_round = data.gamma != 1 || sample_depth == 16; - PNG_CONST double ce = 1. / 32768; - - graylo = digitize(pm, rlo * (data.red_coefficient-ce) + - glo * (data.green_coefficient-ce) + - blo * (data.blue_coefficient-ce), sample_depth, do_round); - if (graylo <= 0) - graylo = 0; - - grayhi = digitize(pm, rhi * (data.red_coefficient+ce) + - ghi * (data.green_coefficient+ce) + - bhi * (data.blue_coefficient+ce), sample_depth, do_round); - if (grayhi >= 1) - grayhi = 1; - } - - /* And invert the gamma. */ - if (data.gamma != 1) - { - PNG_CONST double power = data.gamma; - - gray = pow(gray, power); - graylo = digitize(pm, pow(graylo, power), sample_depth, 1); - grayhi = digitize(pm, pow(grayhi, power), sample_depth, 1); - } - - /* Now the error can be calculated. - * - * If r==g==b because there is no overall gamma correction libpng - * currently preserves the original value. - */ - if (isgray) - err = (that->rede + that->greene + that->bluee)/3; - - else - { - err = fabs(grayhi-gray); - if (fabs(gray - graylo) > err) - err = fabs(graylo-gray); - - /* Check that this worked: */ - if (err > display->pm->limit) - { - size_t pos = 0; - char buffer[128]; - - pos = safecat(buffer, sizeof buffer, pos, "rgb_to_gray error "); - pos = safecatd(buffer, sizeof buffer, pos, err, 6); - pos = safecat(buffer, sizeof buffer, pos, " exceeds limit "); - pos = safecatd(buffer, sizeof buffer, pos, - display->pm->limit, 6); - png_error(pp, buffer); - } - } - } - - that->bluef = that->greenf = that->redf = gray; - that->bluee = that->greene = that->rede = err; - - /* The sBIT is the minium of the three colour channel sBITs. */ - if (that->red_sBIT > that->green_sBIT) - that->red_sBIT = that->green_sBIT; - if (that->red_sBIT > that->blue_sBIT) - that->red_sBIT = that->blue_sBIT; - that->blue_sBIT = that->green_sBIT = that->red_sBIT; - - /* And remove the colour bit in the type: */ - if (that->colour_type == PNG_COLOR_TYPE_RGB) - that->colour_type = PNG_COLOR_TYPE_GRAY; - else if (that->colour_type == PNG_COLOR_TYPE_RGB_ALPHA) - that->colour_type = PNG_COLOR_TYPE_GRAY_ALPHA; - } - - this->next->mod(this->next, that, pp, display); -} - -static int -image_transform_png_set_rgb_to_gray_add(image_transform *this, - PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) -{ - UNUSED(bit_depth) - - this->next = *that; - *that = this; - - return (colour_type & PNG_COLOR_MASK_COLOR) != 0; -} - -#undef data -IT(rgb_to_gray); -#undef PT -#define PT ITSTRUCT(rgb_to_gray) -#undef image_transform_ini -#define image_transform_ini image_transform_default_ini -#endif /* PNG_READ_RGB_TO_GRAY_SUPPORTED */ - -#ifdef PNG_READ_BACKGROUND_SUPPORTED -/* png_set_background(png_structp, png_const_color_16p background_color, - * int background_gamma_code, int need_expand, double background_gamma) - * png_set_background_fixed(png_structp, png_const_color_16p background_color, - * int background_gamma_code, int need_expand, - * png_fixed_point background_gamma) - * - * As with rgb_to_gray this ignores the gamma (at present.) -*/ -#define data ITDATA(background) -static image_pixel data; - -static void -image_transform_png_set_background_set(PNG_CONST image_transform *this, - transform_display *that, png_structp pp, png_infop pi) -{ - png_byte colour_type, bit_depth; - png_byte random_bytes[8]; /* 8 bytes - 64 bits - the biggest pixel */ - png_color_16 back; - - /* We need a background colour, because we don't know exactly what transforms - * have been set we have to supply the colour in the original file format and - * so we need to know what that is! The background colour is stored in the - * transform_display. - */ - RANDOMIZE(random_bytes); - - /* Read the random value, for colour type 3 the background colour is actually - * expressed as a 24bit rgb, not an index. - */ - colour_type = that->this.colour_type; - if (colour_type == 3) - { - colour_type = PNG_COLOR_TYPE_RGB; - bit_depth = 8; - } - - else - bit_depth = that->this.bit_depth; - - image_pixel_init(&data, random_bytes, colour_type, - bit_depth, 0/*x*/, 0/*unused: palette*/); - - /* Extract the background colour from this image_pixel, but make sure the - * unused fields of 'back' are garbage. - */ - RANDOMIZE(back); - - if (colour_type & PNG_COLOR_MASK_COLOR) - { - back.red = (png_uint_16)data.red; - back.green = (png_uint_16)data.green; - back.blue = (png_uint_16)data.blue; - } - - else - back.gray = (png_uint_16)data.red; - -# ifdef PNG_FLOATING_POINT_SUPPORTED - png_set_background(pp, &back, PNG_BACKGROUND_GAMMA_FILE, 1/*need expand*/, - 0); -# else - png_set_background_fixed(pp, &back, PNG_BACKGROUND_GAMMA_FILE, - 1/*need expand*/, 0); -# endif - - this->next->set(this->next, that, pp, pi); -} - -static void -image_transform_png_set_background_mod(PNG_CONST image_transform *this, - image_pixel *that, png_structp pp, PNG_CONST transform_display *display) -{ - /* Check for tRNS first: */ - if (that->have_tRNS && that->colour_type != PNG_COLOR_TYPE_PALETTE) - image_pixel_add_alpha(that, &display->this); - - /* This is only necessary if the alpha value is less than 1. */ - if (that->alphaf < 1) - { - /* Now we do the background calculation without any gamma correction. */ - if (that->alphaf <= 0) - { - that->redf = data.redf; - that->greenf = data.greenf; - that->bluef = data.bluef; - - that->rede = data.rede; - that->greene = data.greene; - that->bluee = data.bluee; - - that->red_sBIT= data.red_sBIT; - that->green_sBIT= data.green_sBIT; - that->blue_sBIT= data.blue_sBIT; - } - - else /* 0 < alpha < 1 */ - { - double alf = 1 - that->alphaf; - - that->redf = that->redf * that->alphaf + data.redf * alf; - that->rede = that->rede * that->alphaf + data.rede * alf + - DBL_EPSILON; - that->greenf = that->greenf * that->alphaf + data.greenf * alf; - that->greene = that->greene * that->alphaf + data.greene * alf + - DBL_EPSILON; - that->bluef = that->bluef * that->alphaf + data.bluef * alf; - that->bluee = that->bluee * that->alphaf + data.bluee * alf + - DBL_EPSILON; - } - - /* Remove the alpha type and set the alpha (not in that order.) */ - that->alphaf = 1; - that->alphae = 0; - - if (that->colour_type == PNG_COLOR_TYPE_RGB_ALPHA) - that->colour_type = PNG_COLOR_TYPE_RGB; - else if (that->colour_type == PNG_COLOR_TYPE_GRAY_ALPHA) - that->colour_type = PNG_COLOR_TYPE_GRAY; - /* PNG_COLOR_TYPE_PALETTE is not changed */ - } - - this->next->mod(this->next, that, pp, display); -} - -#define image_transform_png_set_background_add image_transform_default_add - -#undef data -IT(background); -#undef PT -#define PT ITSTRUCT(background) -#endif /* PNG_READ_BACKGROUND_SUPPORTED */ - -/* This may just be 'end' if all the transforms are disabled! */ -static image_transform *PNG_CONST image_transform_first = &PT; - -static void -transform_enable(PNG_CONST char *name) -{ - /* Everything starts out enabled, so if we see an 'enable' disabled - * everything else the first time round. - */ - static int all_disabled = 0; - int found_it = 0; - image_transform *list = image_transform_first; - - while (list != &image_transform_end) - { - if (strcmp(list->name, name) == 0) - { - list->enable = 1; - found_it = 1; - } - else if (!all_disabled) - list->enable = 0; - - list = list->list; - } - - all_disabled = 1; - - if (!found_it) - { - fprintf(stderr, "pngvalid: --transform-enable=%s: unknown transform\n", - name); - exit(1); - } -} - -static void -transform_disable(PNG_CONST char *name) -{ - image_transform *list = image_transform_first; - - while (list != &image_transform_end) - { - if (strcmp(list->name, name) == 0) - { - list->enable = 0; - return; - } - - list = list->list; - } - - fprintf(stderr, "pngvalid: --transform-disable=%s: unknown transform\n", - name); - exit(1); -} - -static void -image_transform_reset_count(void) -{ - image_transform *next = image_transform_first; - int count = 0; - - while (next != &image_transform_end) - { - next->local_use = 0; - next->next = 0; - next = next->list; - ++count; - } - - /* This can only happen if we every have more than 32 transforms (excluding - * the end) in the list. - */ - if (count > 32) abort(); -} - -static int -image_transform_test_counter(png_uint_32 counter, unsigned int max) -{ - /* Test the list to see if there is any point contining, given a current - * counter and a 'max' value. - */ - image_transform *next = image_transform_first; - - while (next != &image_transform_end) - { - /* For max 0 or 1 continue until the counter overflows: */ - counter >>= 1; - - /* Continue if any entry hasn't reacked the max. */ - if (max > 1 && next->local_use < max) - return 1; - next = next->list; - } - - return max <= 1 && counter == 0; -} - -static png_uint_32 -image_transform_add(PNG_CONST image_transform **this, unsigned int max, - png_uint_32 counter, char *name, size_t sizeof_name, size_t *pos, - png_byte colour_type, png_byte bit_depth) -{ - for (;;) /* until we manage to add something */ - { - png_uint_32 mask; - image_transform *list; - - /* Find the next counter value, if the counter is zero this is the start - * of the list. This routine always returns the current counter (not the - * next) so it returns 0 at the end and expects 0 at the beginning. - */ - if (counter == 0) /* first time */ - { - image_transform_reset_count(); - if (max <= 1) - counter = 1; - else - counter = random_32(); - } - else /* advance the counter */ - { - switch (max) - { - case 0: ++counter; break; - case 1: counter <<= 1; break; - default: counter = random_32(); break; - } - } - - /* Now add all these items, if possible */ - *this = &image_transform_end; - list = image_transform_first; - mask = 1; - - /* Go through the whole list adding anything that the counter selects: */ - while (list != &image_transform_end) - { - if ((counter & mask) != 0 && list->enable && - (max == 0 || list->local_use < max)) - { - /* Candidate to add: */ - if (list->add(list, this, colour_type, bit_depth) || max == 0) - { - /* Added, so add to the name too. */ - *pos = safecat(name, sizeof_name, *pos, " +"); - *pos = safecat(name, sizeof_name, *pos, list->name); - } - - else - { - /* Not useful and max>0, so remove it from *this: */ - *this = list->next; - list->next = 0; - - /* And, since we know it isn't useful, stop it being added again - * in this run: - */ - list->local_use = max; - } - } - - mask <<= 1; - list = list->list; - } - - /* Now if anything was added we have something to do. */ - if (*this != &image_transform_end) - return counter; - - /* Nothing added, but was there anything in there to add? */ - if (!image_transform_test_counter(counter, max)) - return 0; - } -} - -#ifdef THIS_IS_THE_PROFORMA -static void -image_transform_png_set_@_set(PNG_CONST image_transform *this, - transform_display *that, png_structp pp, png_infop pi) -{ - png_set_@(pp); - this->next->set(this->next, that, pp, pi); -} - -static void -image_transform_png_set_@_mod(PNG_CONST image_transform *this, - image_pixel *that, png_structp pp, PNG_CONST transform_display *display) -{ - this->next->mod(this->next, that, pp, display); -} - -static int -image_transform_png_set_@_add(image_transform *this, - PNG_CONST image_transform **that, char *name, size_t sizeof_name, - size_t *pos, png_byte colour_type, png_byte bit_depth) -{ - this->next = *that; - *that = this; - - *pos = safecat(name, sizeof_name, *pos, " +@"); - - return 1; -} - -IT(@); -#endif - -/* png_set_quantize(png_structp, png_colorp palette, int num_palette, - * int maximum_colors, png_const_uint_16p histogram, int full_quantize) - * - * Very difficult to validate this! - */ -/*NOTE: TBD NYI */ - -/* The data layout transforms are handled by swapping our own channel data, - * necessarily these need to happen at the end of the transform list because the - * semantic of the channels changes after these are executed. Some of these, - * like set_shift and set_packing, can't be done at present because they change - * the layout of the data at the sub-sample level so sample() won't get the - * right answer. - */ -/* png_set_invert_alpha */ -/*NOTE: TBD NYI */ - -/* png_set_bgr */ -/*NOTE: TBD NYI */ - -/* png_set_swap_alpha */ -/*NOTE: TBD NYI */ - -/* png_set_swap */ -/*NOTE: TBD NYI */ - -/* png_set_filler, (png_structp png_ptr, png_uint_32 filler, int flags)); */ -/*NOTE: TBD NYI */ - -/* png_set_add_alpha, (png_structp png_ptr, png_uint_32 filler, int flags)); */ -/*NOTE: TBD NYI */ - -/* png_set_packing */ -/*NOTE: TBD NYI */ - -/* png_set_packswap */ -/*NOTE: TBD NYI */ - -/* png_set_invert_mono */ -/*NOTE: TBD NYI */ - -/* png_set_shift(png_structp, png_const_color_8p true_bits) */ -/*NOTE: TBD NYI */ - -static void -perform_transform_test(png_modifier *pm) -{ - png_byte colour_type = 0; - png_byte bit_depth = 0; - int palette_number = 0; - - while (next_format(&colour_type, &bit_depth, &palette_number)) - { - png_uint_32 counter = 0; - size_t base_pos; - char name[64]; - - base_pos = safecat(name, sizeof name, 0, "transform:"); - - for (;;) - { - size_t pos = base_pos; - PNG_CONST image_transform *list = 0; - - /* 'max' is currently hardwired to '1'; this should be settable on the - * command line. - */ - counter = image_transform_add(&list, 1/*max*/, counter, - name, sizeof name, &pos, colour_type, bit_depth); - - if (counter == 0) - break; - - /* The command line can change this to checking interlaced images. */ - do - { - pm->repeat = 0; - transform_test(pm, FILEID(colour_type, bit_depth, palette_number, - pm->interlace_type, 0, 0, 0), list, name); - - if (fail(pm)) - return; - } - while (pm->repeat); - } - } -} -#endif /* PNG_READ_TRANSFORMS_SUPPORTED */ - -/********************************* GAMMA TESTS ********************************/ -#ifdef PNG_READ_GAMMA_SUPPORTED -/* Reader callbacks and implementations, where they differ from the standard - * ones. - */ -typedef struct gamma_display -{ - standard_display this; - - /* Parameters */ - png_modifier* pm; - double file_gamma; - double screen_gamma; - double background_gamma; - png_byte sbit; - int threshold_test; - int use_input_precision; - int scale16; - int expand16; - int do_background; - png_color_16 background_color; - - /* Local variables */ - double maxerrout; - double maxerrpc; - double maxerrabs; -} gamma_display; - -#define ALPHA_MODE_OFFSET 4 - -static void -gamma_display_init(gamma_display *dp, png_modifier *pm, png_uint_32 id, - double file_gamma, double screen_gamma, png_byte sbit, int threshold_test, - int use_input_precision, int scale16, int expand16, - int do_background, PNG_CONST png_color_16 *pointer_to_the_background_color, - double background_gamma) -{ - /* Standard fields */ - standard_display_init(&dp->this, &pm->this, id, 0/*do_interlace*/, - pm->use_update_info); - - /* Parameter fields */ - dp->pm = pm; - dp->file_gamma = file_gamma; - dp->screen_gamma = screen_gamma; - dp->background_gamma = background_gamma; - dp->sbit = sbit; - dp->threshold_test = threshold_test; - dp->use_input_precision = use_input_precision; - dp->scale16 = scale16; - dp->expand16 = expand16; - dp->do_background = do_background; - if (do_background && pointer_to_the_background_color != 0) - dp->background_color = *pointer_to_the_background_color; - else - memset(&dp->background_color, 0, sizeof dp->background_color); - - /* Local variable fields */ - dp->maxerrout = dp->maxerrpc = dp->maxerrabs = 0; -} - -static void -gamma_info_imp(gamma_display *dp, png_structp pp, png_infop pi) -{ - /* Reuse the standard stuff as appropriate. */ - standard_info_part1(&dp->this, pp, pi); - - /* If requested strip 16 to 8 bits - this is handled automagically below - * because the output bit depth is read from the library. Note that there - * are interactions with sBIT but, internally, libpng makes sbit at most - * PNG_MAX_GAMMA_8 when doing the following. - */ - if (dp->scale16) -# ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED - png_set_scale_16(pp); -# else - /* The following works both in 1.5.4 and earlier versions: */ -# ifdef PNG_READ_16_TO_8_SUPPORTED - png_set_strip_16(pp); -# else - png_error(pp, "scale16 (16 to 8 bit conversion) not supported"); -# endif -# endif - - if (dp->expand16) -# ifdef PNG_READ_EXPAND_16_SUPPORTED - png_set_expand_16(pp); -# else - png_error(pp, "expand16 (8 to 16 bit conversion) not supported"); -# endif - - if (dp->do_background >= ALPHA_MODE_OFFSET) - { -# ifdef PNG_READ_ALPHA_MODE_SUPPORTED - { - /* This tests the alpha mode handling, if supported. */ - int mode = dp->do_background - ALPHA_MODE_OFFSET; - - /* The gamma value is the output gamma, and is in the standard, - * non-inverted, represenation. It provides a default for the PNG file - * gamma, but since the file has a gAMA chunk this does not matter. - */ - PNG_CONST double sg = dp->screen_gamma; -# ifndef PNG_FLOATING_POINT_SUPPORTED - PNG_CONST png_fixed_point g = fix(sg); -# endif - -# ifdef PNG_FLOATING_POINT_SUPPORTED - png_set_alpha_mode(pp, mode, sg); -# else - png_set_alpha_mode_fixed(pp, mode, g); -# endif - - /* However, for the standard Porter-Duff algorithm the output defaults - * to be linear, so if the test requires non-linear output it must be - * corrected here. - */ - if (mode == PNG_ALPHA_STANDARD && sg != 1) - { -# ifdef PNG_FLOATING_POINT_SUPPORTED - png_set_gamma(pp, sg, dp->file_gamma); -# else - png_fixed_point f = fix(dp->file_gamma); - png_set_gamma_fixed(pp, g, f); -# endif - } - } -# else - png_error(pp, "alpha mode handling not supported"); -# endif - } - - else - { - /* Set up gamma processing. */ -# ifdef PNG_FLOATING_POINT_SUPPORTED - png_set_gamma(pp, dp->screen_gamma, dp->file_gamma); -# else - { - png_fixed_point s = fix(dp->screen_gamma); - png_fixed_point f = fix(dp->file_gamma); - png_set_gamma_fixed(pp, s, f); - } -# endif - - if (dp->do_background) - { -# ifdef PNG_READ_BACKGROUND_SUPPORTED - /* NOTE: this assumes the caller provided the correct background gamma! - */ - PNG_CONST double bg = dp->background_gamma; -# ifndef PNG_FLOATING_POINT_SUPPORTED - PNG_CONST png_fixed_point g = fix(bg); -# endif - -# ifdef PNG_FLOATING_POINT_SUPPORTED - png_set_background(pp, &dp->background_color, dp->do_background, - 0/*need_expand*/, bg); -# else - png_set_background_fixed(pp, &dp->background_color, - dp->do_background, 0/*need_expand*/, g); -# endif -# else - png_error(pp, "png_set_background not supported"); -# endif - } - } - - { - int i = dp->this.use_update_info; - /* Always do one call, even if use_update_info is 0. */ - do - png_read_update_info(pp, pi); - while (--i > 0); - } - - /* Now we may get a different cbRow: */ - standard_info_part2(&dp->this, pp, pi, 1 /*images*/); -} - -static void -gamma_info(png_structp pp, png_infop pi) -{ - gamma_info_imp(voidcast(gamma_display*, png_get_progressive_ptr(pp)), pp, - pi); -} - -/* Validate a single component value - the routine gets the input and output - * sample values as unscaled PNG component values along with a cache of all the - * information required to validate the values. - */ -typedef struct validate_info -{ - png_structp pp; - gamma_display *dp; - png_byte sbit; - int use_input_precision; - int do_background; - int scale16; - unsigned int sbit_max; - unsigned int isbit_shift; - unsigned int outmax; - - double gamma_correction; /* Overall correction required. */ - double file_inverse; /* Inverse of file gamma. */ - double screen_gamma; - double screen_inverse; /* Inverse of screen gamma. */ - - double background_red; /* Linear background value, red or gray. */ - double background_green; - double background_blue; - - double maxabs; - double maxpc; - double maxcalc; - double maxout; - double maxout_total; /* Total including quantization error */ - double outlog; - int outquant; -} -validate_info; - -static void -init_validate_info(validate_info *vi, gamma_display *dp, png_struct *pp, - int in_depth, int out_depth) -{ - PNG_CONST unsigned int outmax = (1U<pp = pp; - vi->dp = dp; - - if (dp->sbit > 0 && dp->sbit < in_depth) - { - vi->sbit = dp->sbit; - vi->isbit_shift = in_depth - dp->sbit; - } - - else - { - vi->sbit = (png_byte)in_depth; - vi->isbit_shift = 0; - } - - vi->sbit_max = (1U << vi->sbit)-1; - - /* This mimics the libpng threshold test, '0' is used to prevent gamma - * correction in the validation test. - */ - vi->screen_gamma = dp->screen_gamma; - if (fabs(vi->screen_gamma-1) < PNG_GAMMA_THRESHOLD) - vi->screen_gamma = vi->screen_inverse = 0; - else - vi->screen_inverse = 1/vi->screen_gamma; - - vi->use_input_precision = dp->use_input_precision; - vi->outmax = outmax; - vi->maxabs = abserr(dp->pm, in_depth, out_depth); - vi->maxpc = pcerr(dp->pm, in_depth, out_depth); - vi->maxcalc = calcerr(dp->pm, in_depth, out_depth); - vi->maxout = outerr(dp->pm, in_depth, out_depth); - vi->outquant = output_quantization_factor(dp->pm, in_depth, out_depth); - vi->maxout_total = vi->maxout + vi->outquant * .5; - vi->outlog = outlog(dp->pm, in_depth, out_depth); - - if ((dp->this.colour_type & PNG_COLOR_MASK_ALPHA) != 0 || - (dp->this.colour_type == 3 && dp->this.is_transparent)) - { - vi->do_background = dp->do_background; - - if (vi->do_background != 0) - { - PNG_CONST double bg_inverse = 1/dp->background_gamma; - double r, g, b; - - /* Caller must at least put the gray value into the red channel */ - r = dp->background_color.red; r /= outmax; - g = dp->background_color.green; g /= outmax; - b = dp->background_color.blue; b /= outmax; - -# if 0 - /* libpng doesn't do this optimization, if we do pngvalid will fail. - */ - if (fabs(bg_inverse-1) >= PNG_GAMMA_THRESHOLD) -# endif - { - r = pow(r, bg_inverse); - g = pow(g, bg_inverse); - b = pow(b, bg_inverse); - } - - vi->background_red = r; - vi->background_green = g; - vi->background_blue = b; - } - } - else - vi->do_background = 0; - - if (vi->do_background == 0) - vi->background_red = vi->background_green = vi->background_blue = 0; - - vi->gamma_correction = 1/(dp->file_gamma*dp->screen_gamma); - if (fabs(vi->gamma_correction-1) < PNG_GAMMA_THRESHOLD) - vi->gamma_correction = 0; - - vi->file_inverse = 1/dp->file_gamma; - if (fabs(vi->file_inverse-1) < PNG_GAMMA_THRESHOLD) - vi->file_inverse = 0; - - vi->scale16 = dp->scale16; -} - -/* This function handles composition of a single non-alpha component. The - * argument is the input sample value, in the range 0..1, and the alpha value. - * The result is the composed, linear, input sample. If alpha is less than zero - * this is the alpha component and the function should not be called! - */ -static double -gamma_component_compose(int do_background, double input_sample, double alpha, - double background, int *compose) -{ - switch (do_background) - { - case PNG_BACKGROUND_GAMMA_SCREEN: - case PNG_BACKGROUND_GAMMA_FILE: - case PNG_BACKGROUND_GAMMA_UNIQUE: - /* Standard PNG background processing. */ - if (alpha < 1) - { - if (alpha > 0) - { - input_sample = input_sample * alpha + background * (1-alpha); - if (compose != NULL) - *compose = 1; - } - - else - input_sample = background; - } - break; - -#ifdef PNG_READ_ALPHA_MODE_SUPPORTED - case ALPHA_MODE_OFFSET + PNG_ALPHA_STANDARD: - case ALPHA_MODE_OFFSET + PNG_ALPHA_BROKEN: - /* The components are premultiplied in either case and the output is - * gamma encoded (to get standard Porter-Duff we expect the output - * gamma to be set to 1.0!) - */ - case ALPHA_MODE_OFFSET + PNG_ALPHA_OPTIMIZED: - /* The optimization is that the partial-alpha entries are linear - * while the opaque pixels are gamma encoded, but this only affects the - * output encoding. - */ - if (alpha < 1) - { - if (alpha > 0) - { - input_sample *= alpha; - if (compose != NULL) - *compose = 1; - } - - else - input_sample = 0; - } - break; -#endif - - default: - /* Standard cases where no compositing is done (so the component - * value is already correct.) - */ - break; - } - - return input_sample; -} - -/* This API returns the encoded *input* component, in the range 0..1 */ -static double -gamma_component_validate(PNG_CONST char *name, PNG_CONST validate_info *vi, - PNG_CONST unsigned int id, PNG_CONST unsigned int od, - PNG_CONST double alpha /* <0 for the alpha channel itself */, - PNG_CONST double background /* component background value */) -{ - PNG_CONST unsigned int isbit = id >> vi->isbit_shift; - PNG_CONST unsigned int sbit_max = vi->sbit_max; - PNG_CONST unsigned int outmax = vi->outmax; - PNG_CONST int do_background = vi->do_background; - - double i; - - /* First check on the 'perfect' result obtained from the digitized input - * value, id, and compare this against the actual digitized result, 'od'. - * 'i' is the input result in the range 0..1: - */ - i = isbit; i /= sbit_max; - - /* Check for the fast route: if we don't do any background composition or if - * this is the alpha channel ('alpha' < 0) or if the pixel is opaque then - * just use the gamma_correction field to correct to the final output gamma. - */ - if (alpha == 1 /* opaque pixel component */ || !do_background -#ifdef PNG_READ_ALPHA_MODE_SUPPORTED - || do_background == ALPHA_MODE_OFFSET + PNG_ALPHA_PNG -#endif - || (alpha < 0 /* alpha channel */ -#ifdef PNG_READ_ALPHA_MODE_SUPPORTED - && do_background != ALPHA_MODE_OFFSET + PNG_ALPHA_BROKEN -#endif - )) - { - /* Then get the gamma corrected version of 'i' and compare to 'od', any - * error less than .5 is insignificant - just quantization of the output - * value to the nearest digital value (nevertheless the error is still - * recorded - it's interesting ;-) - */ - double encoded_sample = i; - double encoded_error; - - /* alpha less than 0 indicates the alpha channel, which is always linear - */ - if (alpha >= 0 && vi->gamma_correction > 0) - encoded_sample = pow(encoded_sample, vi->gamma_correction); - encoded_sample *= outmax; - - encoded_error = fabs(od-encoded_sample); - - if (encoded_error > vi->dp->maxerrout) - vi->dp->maxerrout = encoded_error; - - if (encoded_error < vi->maxout_total && encoded_error < vi->outlog) - return i; - } - - /* The slow route - attempt to do linear calculations. */ - /* There may be an error, or background processing is required, so calculate - * the actual sample values - unencoded light intensity values. Note that in - * practice these are not completely unencoded because they include a - * 'viewing correction' to decrease or (normally) increase the perceptual - * contrast of the image. There's nothing we can do about this - we don't - * know what it is - so assume the unencoded value is perceptually linear. - */ - { - double input_sample = i; /* In range 0..1 */ - double output, error, encoded_sample, encoded_error; - double es_lo, es_hi; - int compose = 0; /* Set to one if composition done */ - int output_is_encoded; /* Set if encoded to screen gamma */ - int log_max_error = 1; /* Check maximum error values */ - png_const_charp pass = 0; /* Reason test passes (or 0 for fail) */ - - /* Convert to linear light (with the above caveat.) The alpha channel is - * already linear. - */ - if (alpha >= 0) - { - int tcompose; - - if (vi->file_inverse > 0) - input_sample = pow(input_sample, vi->file_inverse); - - /* Handle the compose processing: */ - tcompose = 0; - input_sample = gamma_component_compose(do_background, input_sample, - alpha, background, &tcompose); - - if (tcompose) - compose = 1; - } - - /* And similarly for the output value, but we need to check the background - * handling to linearize it correctly. - */ - output = od; - output /= outmax; - - output_is_encoded = vi->screen_gamma > 0; - - if (alpha < 0) /* The alpha channel */ - { -#ifdef PNG_READ_ALPHA_MODE_SUPPORTED - if (do_background != ALPHA_MODE_OFFSET + PNG_ALPHA_BROKEN) -#endif - { - /* In all other cases the output alpha channel is linear already, - * don't log errors here, they are much larger in linear data. - */ - output_is_encoded = 0; - log_max_error = 0; - } - } - -#ifdef PNG_READ_ALPHA_MODE_SUPPORTED - else /* A component */ - { - if (do_background == ALPHA_MODE_OFFSET + PNG_ALPHA_OPTIMIZED && - alpha < 1) /* the optimized case - linear output */ - { - if (alpha > 0) log_max_error = 0; - output_is_encoded = 0; - } - } -#endif - - if (output_is_encoded) - output = pow(output, vi->screen_gamma); - - /* Calculate (or recalculate) the encoded_sample value and repeat the - * check above (unnecessary if we took the fast route, but harmless.) - */ - encoded_sample = input_sample; - if (output_is_encoded) - encoded_sample = pow(encoded_sample, vi->screen_inverse); - encoded_sample *= outmax; - - encoded_error = fabs(od-encoded_sample); - - /* Don't log errors in the alpha channel, or the 'optimized' case, - * neither are significant to the overall perception. - */ - if (log_max_error && encoded_error > vi->dp->maxerrout) - vi->dp->maxerrout = encoded_error; - - if (encoded_error < vi->maxout_total) - { - if (encoded_error < vi->outlog) - return i; - - /* Test passed but error is bigger than the log limit, record why the - * test passed: - */ - pass = "less than maxout:\n"; - } - - /* i: the original input value in the range 0..1 - * - * pngvalid calculations: - * input_sample: linear result; i linearized and composed, range 0..1 - * encoded_sample: encoded result; input_sample scaled to ouput bit depth - * - * libpng calculations: - * output: linear result; od scaled to 0..1 and linearized - * od: encoded result from libpng - */ - - /* Now we have the numbers for real errors, both absolute values as as a - * percentage of the correct value (output): - */ - error = fabs(input_sample-output); - - if (log_max_error && error > vi->dp->maxerrabs) - vi->dp->maxerrabs = error; - - /* The following is an attempt to ignore the tendency of quantization to - * dominate the percentage errors for lower result values: - */ - if (log_max_error && input_sample > .5) - { - double percentage_error = error/input_sample; - if (percentage_error > vi->dp->maxerrpc) - vi->dp->maxerrpc = percentage_error; - } - - /* Now calculate the digitization limits for 'encoded_sample' using the - * 'max' values. Note that maxout is in the encoded space but maxpc and - * maxabs are in linear light space. - * - * First find the maximum error in linear light space, range 0..1: - */ - { - double tmp = input_sample * vi->maxpc; - if (tmp < vi->maxabs) tmp = vi->maxabs; - /* If 'compose' is true the composition was done in linear space using - * integer arithmetic. This introduces an extra error of +/- 0.5 (at - * least) in the integer space used. 'maxcalc' records this, taking - * into account the possibility that even for 16 bit output 8 bit space - * may have been used. - */ - if (compose && tmp < vi->maxcalc) tmp = vi->maxcalc; - - /* The 'maxout' value refers to the encoded result, to compare with - * this encode input_sample adjusted by the maximum error (tmp) above. - */ - es_lo = encoded_sample - vi->maxout; - - if (es_lo > 0 && input_sample-tmp > 0) - { - double low_value = input_sample-tmp; - if (output_is_encoded) - low_value = pow(low_value, vi->screen_inverse); - low_value *= outmax; - if (low_value < es_lo) es_lo = low_value; - - /* Quantize this appropriately: */ - es_lo = ceil(es_lo / vi->outquant - .5) * vi->outquant; - } - - else - es_lo = 0; - - es_hi = encoded_sample + vi->maxout; - - if (es_hi < outmax && input_sample+tmp < 1) - { - double high_value = input_sample+tmp; - if (output_is_encoded) - high_value = pow(high_value, vi->screen_inverse); - high_value *= outmax; - if (high_value > es_hi) es_hi = high_value; - - es_hi = floor(es_hi / vi->outquant + .5) * vi->outquant; - } - - else - es_hi = outmax; - } - - /* The primary test is that the final encoded value returned by the - * library should be between the two limits (inclusive) that were - * calculated above. - */ - if (od >= es_lo && od <= es_hi) - { - /* The value passes, but we may need to log the information anyway. */ - if (encoded_error < vi->outlog) - return i; - - if (pass == 0) - pass = "within digitization limits:\n"; - } - - { - /* There has been an error in processing, or we need to log this - * value. - */ - double is_lo, is_hi; - - /* pass is set at this point if either of the tests above would have - * passed. Don't do these additional tests here - just log the - * original [es_lo..es_hi] values. - */ - if (pass == 0 && vi->use_input_precision) - { - /* Ok, something is wrong - this actually happens in current libpng - * 16-to-8 processing. Assume that the input value (id, adjusted - * for sbit) can be anywhere between value-.5 and value+.5 - quite a - * large range if sbit is low. - */ - double tmp = (isbit - .5)/sbit_max; - - if (tmp <= 0) - tmp = 0; - - else if (alpha >= 0 && vi->file_inverse > 0 && tmp < 1) - tmp = pow(tmp, vi->file_inverse); - - tmp = gamma_component_compose(do_background, tmp, alpha, background, - NULL); - - if (output_is_encoded && tmp > 0 && tmp < 1) - tmp = pow(tmp, vi->screen_inverse); - - is_lo = ceil(outmax * tmp - vi->maxout_total); - - if (is_lo < 0) - is_lo = 0; - - tmp = (isbit + .5)/sbit_max; - - if (tmp <= 0) - tmp = 0; - - else if (alpha >= 0 && vi->file_inverse > 0 && tmp < 1) - tmp = pow(tmp, vi->file_inverse); - - tmp = gamma_component_compose(do_background, tmp, alpha, background, - NULL); - - if (output_is_encoded && tmp > 0 && tmp < 1) - tmp = pow(tmp, vi->screen_inverse); - - is_hi = floor(outmax * tmp + vi->maxout_total); - - if (is_hi > outmax) - is_hi = outmax; - - if (!(od < is_lo || od > is_hi)) - { - if (encoded_error < vi->outlog) - return i; - - pass = "within input precision limits:\n"; - } - - /* One last chance. If this is an alpha channel and the 16to8 - * option has been used and 'inaccurate' scaling is used then the - * bit reduction is obtained by simply using the top 8 bits of the - * value. - * - * This is only done for older libpng versions when the 'inaccurate' - * (chop) method of scaling was used. - */ -# ifndef PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED -# if PNG_LIBPNG_VER < 10504 - /* This may be required for other components in the future, - * but at present the presence of gamma correction effectively - * prevents the errors in the component scaling (I don't quite - * understand why, but since it's better this way I care not - * to ask, JB 20110419.) - */ - if (pass == 0 && alpha < 0 && vi->scale16 && vi->sbit > 8 && - vi->sbit + vi->isbit_shift == 16) - { - tmp = ((id >> 8) - .5)/255; - - if (tmp > 0) - { - is_lo = ceil(outmax * tmp - vi->maxout_total); - if (is_lo < 0) is_lo = 0; - } - - else - is_lo = 0; - - tmp = ((id >> 8) + .5)/255; - - if (tmp < 1) - { - is_hi = floor(outmax * tmp + vi->maxout_total); - if (is_hi > outmax) is_hi = outmax; - } - - else - is_hi = outmax; - - if (!(od < is_lo || od > is_hi)) - { - if (encoded_error < vi->outlog) - return i; - - pass = "within 8 bit limits:\n"; - } - } -# endif -# endif - } - else /* !use_input_precision */ - is_lo = es_lo, is_hi = es_hi; - - /* Attempt to output a meaningful error/warning message: the message - * output depends on the background/composite operation being performed - * because this changes what parameters were actually used above. - */ - { - size_t pos = 0; - /* Need either 1/255 or 1/65535 precision here; 3 or 6 decimal - * places. Just use outmax to work out which. - */ - int precision = (outmax >= 1000 ? 6 : 3); - int use_input=1, use_background=0, do_compose=0; - char msg[256]; - - if (pass != 0) - pos = safecat(msg, sizeof msg, pos, "\n\t"); - - /* Set up the various flags, the output_is_encoded flag above - * is also used below. do_compose is just a double check. - */ - switch (do_background) - { - case PNG_BACKGROUND_GAMMA_SCREEN: - case PNG_BACKGROUND_GAMMA_FILE: - case PNG_BACKGROUND_GAMMA_UNIQUE: - use_background = (alpha >= 0 && alpha < 1); - /*FALL THROUGH*/ -# ifdef PNG_READ_ALPHA_MODE_SUPPORTED - case ALPHA_MODE_OFFSET + PNG_ALPHA_STANDARD: - case ALPHA_MODE_OFFSET + PNG_ALPHA_BROKEN: - case ALPHA_MODE_OFFSET + PNG_ALPHA_OPTIMIZED: -# endif /* ALPHA_MODE_SUPPORTED */ - do_compose = (alpha > 0 && alpha < 1); - use_input = (alpha != 0); - break; - - default: - break; - } - - /* Check the 'compose' flag */ - if (compose != do_compose) - png_error(vi->pp, "internal error (compose)"); - - /* 'name' is the component name */ - pos = safecat(msg, sizeof msg, pos, name); - pos = safecat(msg, sizeof msg, pos, "("); - pos = safecatn(msg, sizeof msg, pos, id); - if (use_input || pass != 0/*logging*/) - { - if (isbit != id) - { - /* sBIT has reduced the precision of the input: */ - pos = safecat(msg, sizeof msg, pos, ", sbit("); - pos = safecatn(msg, sizeof msg, pos, vi->sbit); - pos = safecat(msg, sizeof msg, pos, "): "); - pos = safecatn(msg, sizeof msg, pos, isbit); - } - pos = safecat(msg, sizeof msg, pos, "/"); - /* The output is either "id/max" or "id sbit(sbit): isbit/max" */ - pos = safecatn(msg, sizeof msg, pos, vi->sbit_max); - } - pos = safecat(msg, sizeof msg, pos, ")"); - - /* A component may have been multiplied (in linear space) by the - * alpha value, 'compose' says whether this is relevant. - */ - if (compose || pass != 0) - { - /* If any form of composition is being done report our - * calculated linear value here (the code above doesn't record - * the input value before composition is performed, so what - * gets reported is the value after composition.) - */ - if (use_input || pass != 0) - { - if (vi->file_inverse > 0) - { - pos = safecat(msg, sizeof msg, pos, "^"); - pos = safecatd(msg, sizeof msg, pos, vi->file_inverse, 2); - } - - else - pos = safecat(msg, sizeof msg, pos, "[linear]"); - - pos = safecat(msg, sizeof msg, pos, "*(alpha)"); - pos = safecatd(msg, sizeof msg, pos, alpha, precision); - } - - /* Now record the *linear* background value if it was used - * (this function is not passed the original, non-linear, - * value but it is contained in the test name.) - */ - if (use_background) - { - pos = safecat(msg, sizeof msg, pos, use_input ? "+" : " "); - pos = safecat(msg, sizeof msg, pos, "(background)"); - pos = safecatd(msg, sizeof msg, pos, background, precision); - pos = safecat(msg, sizeof msg, pos, "*"); - pos = safecatd(msg, sizeof msg, pos, 1-alpha, precision); - } - } - - /* Report the calculated value (input_sample) and the linearized - * libpng value (output) unless this is just a component gamma - * correction. - */ - if (compose || alpha < 0 || pass != 0) - { - pos = safecat(msg, sizeof msg, pos, - pass != 0 ? " =\n\t" : " = "); - pos = safecatd(msg, sizeof msg, pos, input_sample, precision); - pos = safecat(msg, sizeof msg, pos, " (libpng: "); - pos = safecatd(msg, sizeof msg, pos, output, precision); - pos = safecat(msg, sizeof msg, pos, ")"); - - /* Finally report the output gamma encoding, if any. */ - if (output_is_encoded) - { - pos = safecat(msg, sizeof msg, pos, " ^"); - pos = safecatd(msg, sizeof msg, pos, vi->screen_inverse, 2); - pos = safecat(msg, sizeof msg, pos, "(to screen) ="); - } - - else - pos = safecat(msg, sizeof msg, pos, " [screen is linear] ="); - } - - if ((!compose && alpha >= 0) || pass != 0) - { - if (pass != 0) /* logging */ - pos = safecat(msg, sizeof msg, pos, "\n\t[overall:"); - - /* This is the non-composition case, the internal linear - * values are irrelevant (though the log below will reveal - * them.) Output a much shorter warning/error message and report - * the overall gamma correction. - */ - if (vi->gamma_correction > 0) - { - pos = safecat(msg, sizeof msg, pos, " ^"); - pos = safecatd(msg, sizeof msg, pos, vi->gamma_correction, 2); - pos = safecat(msg, sizeof msg, pos, "(gamma correction) ="); - } - - else - pos = safecat(msg, sizeof msg, pos, - " [no gamma correction] ="); - - if (pass != 0) - pos = safecat(msg, sizeof msg, pos, "]"); - } - - /* This is our calculated encoded_sample which should (but does - * not) match od: - */ - pos = safecat(msg, sizeof msg, pos, pass != 0 ? "\n\t" : " "); - pos = safecatd(msg, sizeof msg, pos, is_lo, 1); - pos = safecat(msg, sizeof msg, pos, " < "); - pos = safecatd(msg, sizeof msg, pos, encoded_sample, 1); - pos = safecat(msg, sizeof msg, pos, " (libpng: "); - pos = safecatn(msg, sizeof msg, pos, od); - pos = safecat(msg, sizeof msg, pos, ")"); - pos = safecat(msg, sizeof msg, pos, "/"); - pos = safecatn(msg, sizeof msg, pos, outmax); - pos = safecat(msg, sizeof msg, pos, " < "); - pos = safecatd(msg, sizeof msg, pos, is_hi, 1); - - if (pass == 0) /* The error condition */ - { -# ifdef PNG_WARNINGS_SUPPORTED - png_warning(vi->pp, msg); -# else - store_warning(vi->pp, msg); -# endif - } - - else /* logging this value */ - store_verbose(&vi->dp->pm->this, vi->pp, pass, msg); - } - } - } - - return i; -} - -static void -gamma_image_validate(gamma_display *dp, png_structp pp, png_infop pi) -{ - /* Get some constants derived from the input and output file formats: */ - PNG_CONST png_store* PNG_CONST ps = dp->this.ps; - PNG_CONST png_byte in_ct = dp->this.colour_type; - PNG_CONST png_byte in_bd = dp->this.bit_depth; - PNG_CONST png_uint_32 w = dp->this.w; - PNG_CONST png_uint_32 h = dp->this.h; - PNG_CONST size_t cbRow = dp->this.cbRow; - PNG_CONST png_byte out_ct = png_get_color_type(pp, pi); - PNG_CONST png_byte out_bd = png_get_bit_depth(pp, pi); - - /* There are three sources of error, firstly the quantization in the - * file encoding, determined by sbit and/or the file depth, secondly - * the output (screen) gamma and thirdly the output file encoding. - * - * Since this API receives the screen and file gamma in double - * precision it is possible to calculate an exact answer given an input - * pixel value. Therefore we assume that the *input* value is exact - - * sample/maxsample - calculate the corresponding gamma corrected - * output to the limits of double precision arithmetic and compare with - * what libpng returns. - * - * Since the library must quantize the output to 8 or 16 bits there is - * a fundamental limit on the accuracy of the output of +/-.5 - this - * quantization limit is included in addition to the other limits - * specified by the paramaters to the API. (Effectively, add .5 - * everywhere.) - * - * The behavior of the 'sbit' paramter is defined by section 12.5 - * (sample depth scaling) of the PNG spec. That section forces the - * decoder to assume that the PNG values have been scaled if sBIT is - * present: - * - * png-sample = floor( input-sample * (max-out/max-in) + .5); - * - * This means that only a subset of the possible PNG values should - * appear in the input. However, the spec allows the encoder to use a - * variety of approximations to the above and doesn't require any - * restriction of the values produced. - * - * Nevertheless the spec requires that the upper 'sBIT' bits of the - * value stored in a PNG file be the original sample bits. - * Consequently the code below simply scales the top sbit bits by - * (1<this.palette; - PNG_CONST int in_is_transparent = dp->this.is_transparent; - int out_npalette = -1; - int out_is_transparent = 0; /* Just refers to the palette case */ - store_palette out_palette; - validate_info vi; - - /* Check for row overwrite errors */ - store_image_check(dp->this.ps, pp, 0); - - /* Supply the input and output sample depths here - 8 for an indexed image, - * otherwise the bit depth. - */ - init_validate_info(&vi, dp, pp, in_ct==3?8:in_bd, out_ct==3?8:out_bd); - - processing = (vi.gamma_correction > 0 && !dp->threshold_test) - || in_bd != out_bd || in_ct != out_ct || vi.do_background; - - /* TODO: FIX THIS: MAJOR BUG! If the transformations all happen inside - * the palette there is no way of finding out, because libpng fails to - * update the palette on png_read_update_info. Indeed, libpng doesn't - * even do the required work until much later, when it doesn't have any - * info pointer. Oops. For the moment 'processing' is turned off if - * out_ct is palette. - */ - if (in_ct == 3 && out_ct == 3) - processing = 0; - - if (processing && out_ct == 3) - out_is_transparent = read_palette(out_palette, &out_npalette, pp, pi); - - for (y=0; ythis.palette[in_index].alpha : - sample(std, in_ct, in_bd, x, samples_per_pixel); - - unsigned int output_alpha = 65536 /* as a flag value */; - - if (out_ct == 3) - { - if (out_is_transparent) - output_alpha = out_palette[out_index].alpha; - } - - else if ((out_ct & PNG_COLOR_MASK_ALPHA) != 0) - output_alpha = sample(pRow, out_ct, out_bd, x, - samples_per_pixel); - - if (output_alpha != 65536) - alpha = gamma_component_validate("alpha", &vi, input_alpha, - output_alpha, -1/*alpha*/, 0/*background*/); - - else /* no alpha in output */ - { - /* This is a copy of the calculation of 'i' above in order to - * have the alpha value to use in the background calculation. - */ - alpha = input_alpha >> vi.isbit_shift; - alpha /= vi.sbit_max; - } - } - - /* Handle grayscale or RGB components. */ - if ((in_ct & PNG_COLOR_MASK_COLOR) == 0) /* grayscale */ - (void)gamma_component_validate("gray", &vi, - sample(std, in_ct, in_bd, x, 0), - sample(pRow, out_ct, out_bd, x, 0), alpha/*component*/, - vi.background_red); - else /* RGB or palette */ - { - (void)gamma_component_validate("red", &vi, - in_ct == 3 ? in_palette[in_index].red : - sample(std, in_ct, in_bd, x, 0), - out_ct == 3 ? out_palette[out_index].red : - sample(pRow, out_ct, out_bd, x, 0), - alpha/*component*/, vi.background_red); - - (void)gamma_component_validate("green", &vi, - in_ct == 3 ? in_palette[in_index].green : - sample(std, in_ct, in_bd, x, 1), - out_ct == 3 ? out_palette[out_index].green : - sample(pRow, out_ct, out_bd, x, 1), - alpha/*component*/, vi.background_green); - - (void)gamma_component_validate("blue", &vi, - in_ct == 3 ? in_palette[in_index].blue : - sample(std, in_ct, in_bd, x, 2), - out_ct == 3 ? out_palette[out_index].blue : - sample(pRow, out_ct, out_bd, x, 2), - alpha/*component*/, vi.background_blue); - } - } - } - - else if (memcmp(std, pRow, cbRow) != 0) - { - char msg[64]; - - /* No transform is expected on the threshold tests. */ - sprintf(msg, "gamma: below threshold row %d changed", y); - - png_error(pp, msg); - } - } /* row (y) loop */ - - dp->this.ps->validated = 1; -} - -static void -gamma_end(png_structp pp, png_infop pi) -{ - gamma_display *dp = voidcast(gamma_display*, png_get_progressive_ptr(pp)); - - if (!dp->this.speed) - gamma_image_validate(dp, pp, pi); - else - dp->this.ps->validated = 1; -} - -/* A single test run checking a gamma transformation. - * - * maxabs: maximum absolute error as a fraction - * maxout: maximum output error in the output units - * maxpc: maximum percentage error (as a percentage) - */ -static void -gamma_test(png_modifier *pmIn, PNG_CONST png_byte colour_typeIn, - PNG_CONST png_byte bit_depthIn, PNG_CONST int palette_numberIn, - PNG_CONST int interlace_typeIn, - PNG_CONST double file_gammaIn, PNG_CONST double screen_gammaIn, - PNG_CONST png_byte sbitIn, PNG_CONST int threshold_testIn, - PNG_CONST char *name, - PNG_CONST int use_input_precisionIn, PNG_CONST int scale16In, - PNG_CONST int expand16In, PNG_CONST int do_backgroundIn, - PNG_CONST png_color_16 *bkgd_colorIn, double bkgd_gammaIn) -{ - gamma_display d; - context(&pmIn->this, fault); - - gamma_display_init(&d, pmIn, FILEID(colour_typeIn, bit_depthIn, - palette_numberIn, interlace_typeIn, 0, 0, 0), - file_gammaIn, screen_gammaIn, sbitIn, - threshold_testIn, use_input_precisionIn, scale16In, - expand16In, do_backgroundIn, bkgd_colorIn, bkgd_gammaIn); - - Try - { - png_structp pp; - png_infop pi; - gama_modification gama_mod; - srgb_modification srgb_mod; - sbit_modification sbit_mod; - - /* For the moment don't use the png_modifier support here. */ - d.pm->encoding_counter = 0; - modifier_set_encoding(d.pm); /* Just resets everything */ - d.pm->current_gamma = d.file_gamma; - - /* Make an appropriate modifier to set the PNG file gamma to the - * given gamma value and the sBIT chunk to the given precision. - */ - d.pm->modifications = NULL; - gama_modification_init(&gama_mod, d.pm, d.file_gamma); - srgb_modification_init(&srgb_mod, d.pm, 127 /*delete*/); - if (d.sbit > 0) - sbit_modification_init(&sbit_mod, d.pm, d.sbit); - - modification_reset(d.pm->modifications); - - /* Get a png_struct for writing the image. */ - pp = set_modifier_for_read(d.pm, &pi, d.this.id, name); - standard_palette_init(&d.this); - - /* Introduce the correct read function. */ - if (d.pm->this.progressive) - { - /* Share the row function with the standard implementation. */ - png_set_progressive_read_fn(pp, &d, gamma_info, progressive_row, - gamma_end); - - /* Now feed data into the reader until we reach the end: */ - modifier_progressive_read(d.pm, pp, pi); - } - else - { - /* modifier_read expects a png_modifier* */ - png_set_read_fn(pp, d.pm, modifier_read); - - /* Check the header values: */ - png_read_info(pp, pi); - - /* Process the 'info' requirements. Only one image is generated */ - gamma_info_imp(&d, pp, pi); - - sequential_row(&d.this, pp, pi, -1, 0); - - if (!d.this.speed) - gamma_image_validate(&d, pp, pi); - else - d.this.ps->validated = 1; - } - - modifier_reset(d.pm); - - if (d.pm->log && !d.threshold_test && !d.this.speed) - fprintf(stderr, "%d bit %s %s: max error %f (%.2g, %2g%%)\n", - d.this.bit_depth, colour_types[d.this.colour_type], name, - d.maxerrout, d.maxerrabs, 100*d.maxerrpc); - - /* Log the summary values too. */ - if (d.this.colour_type == 0 || d.this.colour_type == 4) - { - switch (d.this.bit_depth) - { - case 1: - break; - - case 2: - if (d.maxerrout > d.pm->error_gray_2) - d.pm->error_gray_2 = d.maxerrout; - - break; - - case 4: - if (d.maxerrout > d.pm->error_gray_4) - d.pm->error_gray_4 = d.maxerrout; - - break; - - case 8: - if (d.maxerrout > d.pm->error_gray_8) - d.pm->error_gray_8 = d.maxerrout; - - break; - - case 16: - if (d.maxerrout > d.pm->error_gray_16) - d.pm->error_gray_16 = d.maxerrout; - - break; - - default: - png_error(pp, "bad bit depth (internal: 1)"); - } - } - - else if (d.this.colour_type == 2 || d.this.colour_type == 6) - { - switch (d.this.bit_depth) - { - case 8: - - if (d.maxerrout > d.pm->error_color_8) - d.pm->error_color_8 = d.maxerrout; - - break; - - case 16: - - if (d.maxerrout > d.pm->error_color_16) - d.pm->error_color_16 = d.maxerrout; - - break; - - default: - png_error(pp, "bad bit depth (internal: 2)"); - } - } - - else if (d.this.colour_type == 3) - { - if (d.maxerrout > d.pm->error_indexed) - d.pm->error_indexed = d.maxerrout; - } - } - - Catch(fault) - modifier_reset((png_modifier*)fault); -} - -static void gamma_threshold_test(png_modifier *pm, png_byte colour_type, - png_byte bit_depth, int interlace_type, double file_gamma, - double screen_gamma) -{ - size_t pos = 0; - char name[64]; - pos = safecat(name, sizeof name, pos, "threshold "); - pos = safecatd(name, sizeof name, pos, file_gamma, 3); - pos = safecat(name, sizeof name, pos, "/"); - pos = safecatd(name, sizeof name, pos, screen_gamma, 3); - - (void)gamma_test(pm, colour_type, bit_depth, 0/*palette*/, interlace_type, - file_gamma, screen_gamma, 0/*sBIT*/, 1/*threshold test*/, name, - 0 /*no input precision*/, - 0 /*no scale16*/, 0 /*no expand16*/, 0 /*no background*/, 0 /*hence*/, - 0 /*no background gamma*/); -} - -static void -perform_gamma_threshold_tests(png_modifier *pm) -{ - png_byte colour_type = 0; - png_byte bit_depth = 0; - int palette_number = 0; - - /* Don't test more than one instance of each palette - it's pointless, in - * fact this test is somewhat excessive since libpng doesn't make this - * decision based on colour type or bit depth! - */ - while (next_format(&colour_type, &bit_depth, &palette_number)) - if (palette_number == 0) - { - double test_gamma = 1.0; - while (test_gamma >= .4) - { - /* There's little point testing the interlacing vs non-interlacing, - * but this can be set from the command line. - */ - gamma_threshold_test(pm, colour_type, bit_depth, pm->interlace_type, - test_gamma, 1/test_gamma); - test_gamma *= .95; - } - - /* And a special test for sRGB */ - gamma_threshold_test(pm, colour_type, bit_depth, pm->interlace_type, - .45455, 2.2); - - if (fail(pm)) - return; - } -} - -static void gamma_transform_test(png_modifier *pm, - PNG_CONST png_byte colour_type, PNG_CONST png_byte bit_depth, - PNG_CONST int palette_number, - PNG_CONST int interlace_type, PNG_CONST double file_gamma, - PNG_CONST double screen_gamma, PNG_CONST png_byte sbit, - PNG_CONST int use_input_precision, PNG_CONST int scale16) -{ - size_t pos = 0; - char name[64]; - - if (sbit != bit_depth && sbit != 0) - { - pos = safecat(name, sizeof name, pos, "sbit("); - pos = safecatn(name, sizeof name, pos, sbit); - pos = safecat(name, sizeof name, pos, ") "); - } - - else - pos = safecat(name, sizeof name, pos, "gamma "); - - if (scale16) - pos = safecat(name, sizeof name, pos, "16to8 "); - - pos = safecatd(name, sizeof name, pos, file_gamma, 3); - pos = safecat(name, sizeof name, pos, "->"); - pos = safecatd(name, sizeof name, pos, screen_gamma, 3); - - gamma_test(pm, colour_type, bit_depth, palette_number, interlace_type, - file_gamma, screen_gamma, sbit, 0, name, use_input_precision, - scale16, pm->test_gamma_expand16, 0 , 0, 0); -} - -static void perform_gamma_transform_tests(png_modifier *pm) -{ - png_byte colour_type = 0; - png_byte bit_depth = 0; - int palette_number = 0; - - while (next_format(&colour_type, &bit_depth, &palette_number)) - { - unsigned int i, j; - - for (i=0; ingamma_tests; ++i) for (j=0; jngamma_tests; ++j) - if (i != j) - { - gamma_transform_test(pm, colour_type, bit_depth, palette_number, - pm->interlace_type, 1/pm->gammas[i], pm->gammas[j], 0/*sBIT*/, - pm->use_input_precision, 0 /*do not scale16*/); - - if (fail(pm)) - return; - } - } -} - -static void perform_gamma_sbit_tests(png_modifier *pm) -{ - png_byte sbit; - - /* The only interesting cases are colour and grayscale, alpha is ignored here - * for overall speed. Only bit depths where sbit is less than the bit depth - * are tested. - */ - for (sbit=pm->sbitlow; sbit<(1<ngamma_tests; ++i) - { - unsigned int j; - - for (j=0; jngamma_tests; ++j) if (i != j) - { - gamma_transform_test(pm, colour_type, bit_depth, npalette, - pm->interlace_type, 1/pm->gammas[i], pm->gammas[j], - sbit, pm->use_input_precision_sbit, 0 /*scale16*/); - - if (fail(pm)) - return; - } - } - } - } -} - -/* Note that this requires a 16 bit source image but produces 8 bit output, so - * we only need the 16bit write support, but the 16 bit images are only - * generated if DO_16BIT is defined. - */ -#ifdef DO_16BIT -static void perform_gamma_scale16_tests(png_modifier *pm) -{ -# ifndef PNG_MAX_GAMMA_8 -# define PNG_MAX_GAMMA_8 11 -# endif - /* Include the alpha cases here. Note that sbit matches the internal value - * used by the library - otherwise we will get spurious errors from the - * internal sbit style approximation. - * - * The threshold test is here because otherwise the 16 to 8 conversion will - * proceed *without* gamma correction, and the tests above will fail (but not - * by much) - this could be fixed, it only appears with the -g option. - */ - unsigned int i, j; - for (i=0; ingamma_tests; ++i) - { - for (j=0; jngamma_tests; ++j) - { - if (i != j && - fabs(pm->gammas[j]/pm->gammas[i]-1) >= PNG_GAMMA_THRESHOLD) - { - gamma_transform_test(pm, 0, 16, 0, pm->interlace_type, - 1/pm->gammas[i], pm->gammas[j], PNG_MAX_GAMMA_8, - pm->use_input_precision_16to8, 1 /*scale16*/); - - if (fail(pm)) - return; - - gamma_transform_test(pm, 2, 16, 0, pm->interlace_type, - 1/pm->gammas[i], pm->gammas[j], PNG_MAX_GAMMA_8, - pm->use_input_precision_16to8, 1 /*scale16*/); - - if (fail(pm)) - return; - - gamma_transform_test(pm, 4, 16, 0, pm->interlace_type, - 1/pm->gammas[i], pm->gammas[j], PNG_MAX_GAMMA_8, - pm->use_input_precision_16to8, 1 /*scale16*/); - - if (fail(pm)) - return; - - gamma_transform_test(pm, 6, 16, 0, pm->interlace_type, - 1/pm->gammas[i], pm->gammas[j], PNG_MAX_GAMMA_8, - pm->use_input_precision_16to8, 1 /*scale16*/); - - if (fail(pm)) - return; - } - } - } -} -#endif /* 16 to 8 bit conversion */ - -#if defined PNG_READ_BACKGROUND_SUPPORTED ||\ - defined PNG_READ_ALPHA_MODE_SUPPORTED -static void gamma_composition_test(png_modifier *pm, - PNG_CONST png_byte colour_type, PNG_CONST png_byte bit_depth, - PNG_CONST int palette_number, - PNG_CONST int interlace_type, PNG_CONST double file_gamma, - PNG_CONST double screen_gamma, - PNG_CONST int use_input_precision, PNG_CONST int do_background, - PNG_CONST int expand_16) -{ - size_t pos = 0; - png_const_charp base; - double bg; - char name[128]; - png_color_16 background; - - /* Make up a name and get an appropriate background gamma value. */ - switch (do_background) - { - default: - base = ""; - bg = 4; /* should not be used */ - break; - case PNG_BACKGROUND_GAMMA_SCREEN: - base = " bckg(Screen):"; - bg = 1/screen_gamma; - break; - case PNG_BACKGROUND_GAMMA_FILE: - base = " bckg(File):"; - bg = file_gamma; - break; - case PNG_BACKGROUND_GAMMA_UNIQUE: - base = " bckg(Unique):"; - /* This tests the handling of a unique value, the math is such that the - * value tends to be <1, but is neither screen nor file (even if they - * match!) - */ - bg = (file_gamma + screen_gamma) / 3; - break; -#ifdef PNG_READ_ALPHA_MODE_SUPPORTED - case ALPHA_MODE_OFFSET + PNG_ALPHA_PNG: - base = " alpha(PNG)"; - bg = 4; /* should not be used */ - break; - case ALPHA_MODE_OFFSET + PNG_ALPHA_STANDARD: - base = " alpha(Porter-Duff)"; - bg = 4; /* should not be used */ - break; - case ALPHA_MODE_OFFSET + PNG_ALPHA_OPTIMIZED: - base = " alpha(Optimized)"; - bg = 4; /* should not be used */ - break; - case ALPHA_MODE_OFFSET + PNG_ALPHA_BROKEN: - base = " alpha(Broken)"; - bg = 4; /* should not be used */ - break; -#endif - } - - /* Use random background values - the background is always presented in the - * output space (8 or 16 bit components). - */ - if (expand_16 || bit_depth == 16) - { - png_uint_32 r = random_32(); - - background.red = (png_uint_16)r; - background.green = (png_uint_16)(r >> 16); - r = random_32(); - background.blue = (png_uint_16)r; - background.gray = (png_uint_16)(r >> 16); - } - - else /* 8 bit colors */ - { - png_uint_32 r = random_32(); - - background.red = (png_byte)r; - background.green = (png_byte)(r >> 8); - background.blue = (png_byte)(r >> 16); - background.gray = (png_byte)(r >> 24); - } - - background.index = 193; /* rgb(193,193,193) to detect errors */ - if (!(colour_type & PNG_COLOR_MASK_COLOR)) - { - /* Grayscale input, we do not convert to RGB (TBD), so we must set the - * background to gray - else libpng seems to fail. - */ - background.red = background.green = background.blue = background.gray; - } - - pos = safecat(name, sizeof name, pos, "gamma "); - pos = safecatd(name, sizeof name, pos, file_gamma, 3); - pos = safecat(name, sizeof name, pos, "->"); - pos = safecatd(name, sizeof name, pos, screen_gamma, 3); - - pos = safecat(name, sizeof name, pos, base); - if (do_background < ALPHA_MODE_OFFSET) - { - /* Include the background color and gamma in the name: */ - pos = safecat(name, sizeof name, pos, "("); - /* This assumes no expand gray->rgb - the current code won't handle that! - */ - if (colour_type & PNG_COLOR_MASK_COLOR) - { - pos = safecatn(name, sizeof name, pos, background.red); - pos = safecat(name, sizeof name, pos, ","); - pos = safecatn(name, sizeof name, pos, background.green); - pos = safecat(name, sizeof name, pos, ","); - pos = safecatn(name, sizeof name, pos, background.blue); - } - else - pos = safecatn(name, sizeof name, pos, background.gray); - pos = safecat(name, sizeof name, pos, ")^"); - pos = safecatd(name, sizeof name, pos, bg, 3); - } - - gamma_test(pm, colour_type, bit_depth, palette_number, interlace_type, - file_gamma, screen_gamma, 0/*sBIT*/, 0, name, use_input_precision, - 0/*strip 16*/, expand_16, do_background, &background, bg); -} - - -static void -perform_gamma_composition_tests(png_modifier *pm, int do_background, - int expand_16) -{ - png_byte colour_type = 0; - png_byte bit_depth = 0; - int palette_number = 0; - - /* Skip the non-alpha cases - there is no setting of a transparency colour at - * present. - */ - while (next_format(&colour_type, &bit_depth, &palette_number)) - if ((colour_type & PNG_COLOR_MASK_ALPHA) != 0) - { - unsigned int i, j; - - /* Don't skip the i==j case here - it's relevant. */ - for (i=0; ingamma_tests; ++i) for (j=0; jngamma_tests; ++j) - { - gamma_composition_test(pm, colour_type, bit_depth, palette_number, - pm->interlace_type, 1/pm->gammas[i], pm->gammas[j], - pm->use_input_precision, do_background, expand_16); - - if (fail(pm)) - return; - } - } -} -#endif /* READ_BACKGROUND || READ_ALPHA_MODE */ - -static void -init_gamma_errors(png_modifier *pm) -{ - pm->error_gray_2 = pm->error_gray_4 = pm->error_gray_8 = 0; - pm->error_color_8 = 0; - pm->error_indexed = 0; - pm->error_gray_16 = pm->error_color_16 = 0; -} - -static void -summarize_gamma_errors(png_modifier *pm, png_const_charp who, int low_bit_depth) -{ - if (who) - printf("Gamma correction with %s:\n", who); - - if (low_bit_depth) - { - printf(" 2 bit gray: %.5f\n", pm->error_gray_2); - printf(" 4 bit gray: %.5f\n", pm->error_gray_4); - printf(" 8 bit gray: %.5f\n", pm->error_gray_8); - printf(" 8 bit color: %.5f\n", pm->error_color_8); - printf(" indexed: %.5f\n", pm->error_indexed); - } - -#ifdef DO_16BIT - printf(" 16 bit gray: %.5f\n", pm->error_gray_16); - printf(" 16 bit color: %.5f\n", pm->error_color_16); -#endif -} - -static void -perform_gamma_test(png_modifier *pm, int summary) -{ - /*TODO: remove this*/ - /* Save certain values for the temporary overrides below. */ - unsigned int calculations_use_input_precision = - pm->calculations_use_input_precision; - double maxout8 = pm->maxout8; - - /* First some arbitrary no-transform tests: */ - if (!pm->this.speed && pm->test_gamma_threshold) - { - perform_gamma_threshold_tests(pm); - - if (fail(pm)) - return; - } - - /* Now some real transforms. */ - if (pm->test_gamma_transform) - { - init_gamma_errors(pm); - /*TODO: remove this. Necessary because the current libpng - * implementation works in 8 bits: - */ - if (pm->test_gamma_expand16) - pm->calculations_use_input_precision = 1; - perform_gamma_transform_tests(pm); - if (!calculations_use_input_precision) - pm->calculations_use_input_precision = 0; - - if (summary) - { - printf("Gamma correction error summary\n\n"); - printf("The printed value is the maximum error in the pixel values\n"); - printf("calculated by the libpng gamma correction code. The error\n"); - printf("is calculated as the difference between the output pixel\n"); - printf("value (always an integer) and the ideal value from the\n"); - printf("libpng specification (typically not an integer).\n\n"); - - printf("Expect this value to be less than .5 for 8 bit formats,\n"); - printf("less than 1 for formats with fewer than 8 bits and a small\n"); - printf("number (typically less than 5) for the 16 bit formats.\n"); - printf("For performance reasons the value for 16 bit formats\n"); - printf("increases when the image file includes an sBIT chunk.\n\n"); - - summarize_gamma_errors(pm, 0/*who*/, 1); - } - } - - /* The sbit tests produce much larger errors: */ - if (pm->test_gamma_sbit) - { - init_gamma_errors(pm); - perform_gamma_sbit_tests(pm); - - if (summary) - summarize_gamma_errors(pm, "sBIT", pm->sbitlow < 8U); - } - -#ifdef DO_16BIT /* Should be READ_16BIT_SUPPORTED */ - if (pm->test_gamma_scale16) - { - /* The 16 to 8 bit strip operations: */ - init_gamma_errors(pm); - perform_gamma_scale16_tests(pm); - - if (summary) - { - printf("Gamma correction with 16 to 8 bit reduction:\n"); - printf(" 16 bit gray: %.5f\n", pm->error_gray_16); - printf(" 16 bit color: %.5f\n", pm->error_color_16); - } - } -#endif - -#ifdef PNG_READ_BACKGROUND_SUPPORTED - if (pm->test_gamma_background) - { - init_gamma_errors(pm); - - /*TODO: remove this. Necessary because the current libpng - * implementation works in 8 bits: - */ - if (pm->test_gamma_expand16) - { - pm->calculations_use_input_precision = 1; - pm->maxout8 = .499; /* because the 16 bit background is smashed */ - } - perform_gamma_composition_tests(pm, PNG_BACKGROUND_GAMMA_UNIQUE, - pm->test_gamma_expand16); - if (!calculations_use_input_precision) - pm->calculations_use_input_precision = 0; - pm->maxout8 = maxout8; - - if (summary) - summarize_gamma_errors(pm, "background", 1); - } -#endif - -#ifdef PNG_READ_ALPHA_MODE_SUPPORTED - if (pm->test_gamma_alpha_mode) - { - int do_background; - - init_gamma_errors(pm); - - /*TODO: remove this. Necessary because the current libpng - * implementation works in 8 bits: - */ - if (pm->test_gamma_expand16) - pm->calculations_use_input_precision = 1; - for (do_background = ALPHA_MODE_OFFSET + PNG_ALPHA_STANDARD; - do_background <= ALPHA_MODE_OFFSET + PNG_ALPHA_BROKEN && !fail(pm); - ++do_background) - perform_gamma_composition_tests(pm, do_background, - pm->test_gamma_expand16); - if (!calculations_use_input_precision) - pm->calculations_use_input_precision = 0; - - if (summary) - summarize_gamma_errors(pm, "alpha mode", 1); - } -#endif -} -#endif /* PNG_READ_GAMMA_SUPPORTED */ - -/* INTERLACE MACRO VALIDATION */ -/* This is copied verbatim from the specification, it is simply the pass - * number in which each pixel in each 8x8 tile appears. The array must - * be indexed adam7[y][x] and notice that the pass numbers are based at - * 1, not 0 - the base libpng uses. - */ -static PNG_CONST -png_byte adam7[8][8] = -{ - { 1,6,4,6,2,6,4,6 }, - { 7,7,7,7,7,7,7,7 }, - { 5,6,5,6,5,6,5,6 }, - { 7,7,7,7,7,7,7,7 }, - { 3,6,4,6,3,6,4,6 }, - { 7,7,7,7,7,7,7,7 }, - { 5,6,5,6,5,6,5,6 }, - { 7,7,7,7,7,7,7,7 } -}; - -/* This routine validates all the interlace support macros in png.h for - * a variety of valid PNG widths and heights. It uses a number of similarly - * named internal routines that feed off the above array. - */ -static png_uint_32 -png_pass_start_row(int pass) -{ - int x, y; - ++pass; - for (y=0; y<8; ++y) for (x=0; x<8; ++x) if (adam7[y][x] == pass) - return y; - return 0xf; -} - -static png_uint_32 -png_pass_start_col(int pass) -{ - int x, y; - ++pass; - for (x=0; x<8; ++x) for (y=0; y<8; ++y) if (adam7[y][x] == pass) - return x; - return 0xf; -} - -static int -png_pass_row_shift(int pass) -{ - int x, y, base=(-1), inc=8; - ++pass; - for (y=0; y<8; ++y) for (x=0; x<8; ++x) if (adam7[y][x] == pass) - { - if (base == (-1)) - base = y; - else if (base == y) - {} - else if (inc == y-base) - base=y; - else if (inc == 8) - inc = y-base, base=y; - else if (inc != y-base) - return 0xff; /* error - more than one 'inc' value! */ - } - - if (base == (-1)) return 0xfe; /* error - no row in pass! */ - - /* The shift is always 1, 2 or 3 - no pass has all the rows! */ - switch (inc) - { -case 2: return 1; -case 4: return 2; -case 8: return 3; -default: break; - } - - /* error - unrecognized 'inc' */ - return (inc << 8) + 0xfd; -} - -static int -png_pass_col_shift(int pass) -{ - int x, y, base=(-1), inc=8; - ++pass; - for (x=0; x<8; ++x) for (y=0; y<8; ++y) if (adam7[y][x] == pass) - { - if (base == (-1)) - base = x; - else if (base == x) - {} - else if (inc == x-base) - base=x; - else if (inc == 8) - inc = x-base, base=x; - else if (inc != x-base) - return 0xff; /* error - more than one 'inc' value! */ - } - - if (base == (-1)) return 0xfe; /* error - no row in pass! */ - - /* The shift is always 1, 2 or 3 - no pass has all the rows! */ - switch (inc) - { -case 1: return 0; /* pass 7 has all the columns */ -case 2: return 1; -case 4: return 2; -case 8: return 3; -default: break; - } - - /* error - unrecognized 'inc' */ - return (inc << 8) + 0xfd; -} - -static png_uint_32 -png_row_from_pass_row(png_uint_32 yIn, int pass) -{ - /* By examination of the array: */ - switch (pass) - { -case 0: return yIn * 8; -case 1: return yIn * 8; -case 2: return yIn * 8 + 4; -case 3: return yIn * 4; -case 4: return yIn * 4 + 2; -case 5: return yIn * 2; -case 6: return yIn * 2 + 1; -default: break; - } - - return 0xff; /* bad pass number */ -} - -static png_uint_32 -png_col_from_pass_col(png_uint_32 xIn, int pass) -{ - /* By examination of the array: */ - switch (pass) - { -case 0: return xIn * 8; -case 1: return xIn * 8 + 4; -case 2: return xIn * 4; -case 3: return xIn * 4 + 2; -case 4: return xIn * 2; -case 5: return xIn * 2 + 1; -case 6: return xIn; -default: break; - } - - return 0xff; /* bad pass number */ -} - -static int -png_row_in_interlace_pass(png_uint_32 y, int pass) -{ - /* Is row 'y' in pass 'pass'? */ - int x; - y &= 7; - ++pass; - for (x=0; x<8; ++x) if (adam7[y][x] == pass) - return 1; - - return 0; -} - -static int -png_col_in_interlace_pass(png_uint_32 x, int pass) -{ - /* Is column 'x' in pass 'pass'? */ - int y; - x &= 7; - ++pass; - for (y=0; y<8; ++y) if (adam7[y][x] == pass) - return 1; - - return 0; -} - -static png_uint_32 -png_pass_rows(png_uint_32 height, int pass) -{ - png_uint_32 tiles = height>>3; - png_uint_32 rows = 0; - unsigned int x, y; - - height &= 7; - ++pass; - for (y=0; y<8; ++y) for (x=0; x<8; ++x) if (adam7[y][x] == pass) - { - rows += tiles; - if (y < height) ++rows; - break; /* i.e. break the 'x', column, loop. */ - } - - return rows; -} - -static png_uint_32 -png_pass_cols(png_uint_32 width, int pass) -{ - png_uint_32 tiles = width>>3; - png_uint_32 cols = 0; - unsigned int x, y; - - width &= 7; - ++pass; - for (x=0; x<8; ++x) for (y=0; y<8; ++y) if (adam7[y][x] == pass) - { - cols += tiles; - if (x < width) ++cols; - break; /* i.e. break the 'y', row, loop. */ - } - - return cols; -} - -static void -perform_interlace_macro_validation(void) -{ - /* The macros to validate, first those that depend only on pass: - * - * PNG_PASS_START_ROW(pass) - * PNG_PASS_START_COL(pass) - * PNG_PASS_ROW_SHIFT(pass) - * PNG_PASS_COL_SHIFT(pass) - */ - int pass; - - for (pass=0; pass<7; ++pass) - { - png_uint_32 m, f, v; - - m = PNG_PASS_START_ROW(pass); - f = png_pass_start_row(pass); - if (m != f) - { - fprintf(stderr, "PNG_PASS_START_ROW(%d) = %u != %x\n", pass, m, f); - exit(1); - } - - m = PNG_PASS_START_COL(pass); - f = png_pass_start_col(pass); - if (m != f) - { - fprintf(stderr, "PNG_PASS_START_COL(%d) = %u != %x\n", pass, m, f); - exit(1); - } - - m = PNG_PASS_ROW_SHIFT(pass); - f = png_pass_row_shift(pass); - if (m != f) - { - fprintf(stderr, "PNG_PASS_ROW_SHIFT(%d) = %u != %x\n", pass, m, f); - exit(1); - } - - m = PNG_PASS_COL_SHIFT(pass); - f = png_pass_col_shift(pass); - if (m != f) - { - fprintf(stderr, "PNG_PASS_COL_SHIFT(%d) = %u != %x\n", pass, m, f); - exit(1); - } - - /* Macros that depend on the image or sub-image height too: - * - * PNG_PASS_ROWS(height, pass) - * PNG_PASS_COLS(width, pass) - * PNG_ROW_FROM_PASS_ROW(yIn, pass) - * PNG_COL_FROM_PASS_COL(xIn, pass) - * PNG_ROW_IN_INTERLACE_PASS(y, pass) - * PNG_COL_IN_INTERLACE_PASS(x, pass) - */ - for (v=0;;) - { - /* First the base 0 stuff: */ - m = PNG_ROW_FROM_PASS_ROW(v, pass); - f = png_row_from_pass_row(v, pass); - if (m != f) - { - fprintf(stderr, "PNG_ROW_FROM_PASS_ROW(%u, %d) = %u != %x\n", - v, pass, m, f); - exit(1); - } - - m = PNG_COL_FROM_PASS_COL(v, pass); - f = png_col_from_pass_col(v, pass); - if (m != f) - { - fprintf(stderr, "PNG_COL_FROM_PASS_COL(%u, %d) = %u != %x\n", - v, pass, m, f); - exit(1); - } - - m = PNG_ROW_IN_INTERLACE_PASS(v, pass); - f = png_row_in_interlace_pass(v, pass); - if (m != f) - { - fprintf(stderr, "PNG_ROW_IN_INTERLACE_PASS(%u, %d) = %u != %x\n", - v, pass, m, f); - exit(1); - } - - m = PNG_COL_IN_INTERLACE_PASS(v, pass); - f = png_col_in_interlace_pass(v, pass); - if (m != f) - { - fprintf(stderr, "PNG_COL_IN_INTERLACE_PASS(%u, %d) = %u != %x\n", - v, pass, m, f); - exit(1); - } - - /* Then the base 1 stuff: */ - ++v; - m = PNG_PASS_ROWS(v, pass); - f = png_pass_rows(v, pass); - if (m != f) - { - fprintf(stderr, "PNG_PASS_ROWS(%u, %d) = %u != %x\n", - v, pass, m, f); - exit(1); - } - - m = PNG_PASS_COLS(v, pass); - f = png_pass_cols(v, pass); - if (m != f) - { - fprintf(stderr, "PNG_PASS_COLS(%u, %d) = %u != %x\n", - v, pass, m, f); - exit(1); - } - - /* Move to the next v - the stepping algorithm starts skipping - * values above 1024. - */ - if (v > 1024) - { - if (v == PNG_UINT_31_MAX) - break; - - v = (v << 1) ^ v; - if (v >= PNG_UINT_31_MAX) - v = PNG_UINT_31_MAX-1; - } - } - } -} - -/* Test color encodings. These values are back-calculated from the published - * chromaticities. The values are accurate to about 14 decimal places; 15 are - * given. These values are much more accurate than the ones given in the spec, - * which typically don't exceed 4 decimal places. This allows testing of the - * libpng code to its theoretical accuracy of 4 decimal places. (If pngvalid - * used the published errors the 'slack' permitted would have to be +/-.5E-4 or - * more.) - * - * The png_modifier code assumes that encodings[0] is sRGB and treats it - * specially: do not change the first entry in this list! - */ -static PNG_CONST color_encoding test_encodings[] = -{ -/* sRGB: must be first in this list! */ -/*gamma:*/ { 1/2.2, -/*red: */ { 0.412390799265959, 0.212639005871510, 0.019330818715592 }, -/*green:*/ { 0.357584339383878, 0.715168678767756, 0.119194779794626 }, -/*blue: */ { 0.180480788401834, 0.072192315360734, 0.950532152249660} }, -/* Kodak ProPhoto (wide gamut) */ -/*gamma:*/ { 1/1.6 /*approximate: uses 1.8 power law compared to sRGB 2.4*/, -/*red: */ { 0.797760489672303, 0.288071128229293, 0.000000000000000 }, -/*green:*/ { 0.135185837175740, 0.711843217810102, 0.000000000000000 }, -/*blue: */ { 0.031349349581525, 0.000085653960605, 0.825104602510460} }, -/* Adobe RGB (1998) */ -/*gamma:*/ { 1/(2+51./256), -/*red: */ { 0.576669042910131, 0.297344975250536, 0.027031361386412 }, -/*green:*/ { 0.185558237906546, 0.627363566255466, 0.070688852535827 }, -/*blue: */ { 0.188228646234995, 0.075291458493998, 0.991337536837639} }, -/* Adobe Wide Gamut RGB */ -/*gamma:*/ { 1/(2+51./256), -/*red: */ { 0.716500716779386, 0.258728243040113, 0.000000000000000 }, -/*green:*/ { 0.101020574397477, 0.724682314948566, 0.051211818965388 }, -/*blue: */ { 0.146774385252705, 0.016589442011321, 0.773892783545073} }, -}; - -/* main program */ -int main(int argc, PNG_CONST char **argv) -{ - volatile int summary = 1; /* Print the error summary at the end */ - volatile int memstats = 0; /* Print memory statistics at the end */ - - /* Create the given output file on success: */ - PNG_CONST char *volatile touch = NULL; - - /* This is an array of standard gamma values (believe it or not I've seen - * every one of these mentioned somewhere.) - * - * In the following list the most useful values are first! - */ - static double - gammas[]={2.2, 1.0, 2.2/1.45, 1.8, 1.5, 2.4, 2.5, 2.62, 2.9}; - - /* This records the command and arguments: */ - size_t cp = 0; - char command[1024]; - - png_modifier pm; - context(&pm.this, fault); - - modifier_init(&pm); - - /* Preallocate the image buffer, because we know how big it needs to be, - * note that, for testing purposes, it is deliberately mis-aligned by tag - * bytes either side. All rows have an additional five bytes of padding for - * overwrite checking. - */ - store_ensure_image(&pm.this, NULL, 2, TRANSFORM_ROWMAX, TRANSFORM_HEIGHTMAX); - - /* Don't give argv[0], it's normally some horrible libtool string: */ - cp = safecat(command, sizeof command, cp, "pngvalid"); - - /* Default to error on warning: */ - pm.this.treat_warnings_as_errors = 1; - - /* Store the test gammas */ - pm.gammas = gammas; - pm.ngammas = (sizeof gammas) / (sizeof gammas[0]); - pm.ngamma_tests = 0; /* default to off */ - - /* And the test encodings */ - pm.encodings = test_encodings; - pm.nencodings = (sizeof test_encodings) / (sizeof test_encodings[0]); - - pm.sbitlow = 8U; /* because libpng doesn't do sBIT below 8! */ - /* The following allows results to pass if they correspond to anything in the - * transformed range [input-.5,input+.5]; this is is required because of the - * way libpng treates the 16_TO_8 flag when building the gamma tables. - * - * TODO: review this - */ - pm.use_input_precision_16to8 = 1U; - - /* Some default values (set the behavior for 'make check' here). - * These values simply control the maximum error permitted in the gamma - * transformations. The practial limits for human perception are described - * below (the setting for maxpc16), however for 8 bit encodings it isn't - * possible to meet the accepted capabilities of human vision - i.e. 8 bit - * images can never be good enough, regardless of encoding. - */ - pm.maxout8 = .1; /* Arithmetic error in *encoded* value */ - pm.maxabs8 = .00005; /* 1/20000 */ - pm.maxcalc8 = .004; /* +/-1 in 8 bits for compose errors */ - pm.maxpc8 = .499; /* I.e., .499% fractional error */ - pm.maxout16 = .499; /* Error in *encoded* value */ - pm.maxabs16 = .00005;/* 1/20000 */ - pm.maxcalc16 =.000015;/* +/-1 in 16 bits for compose errors */ - - /* NOTE: this is a reasonable perceptual limit. We assume that humans can - * perceive light level differences of 1% over a 100:1 range, so we need to - * maintain 1 in 10000 accuracy (in linear light space), which is what the - * following guarantees. It also allows significantly higher errors at - * higher 16 bit values, which is important for performance. The actual - * maximum 16 bit error is about +/-1.9 in the fixed point implementation but - * this is only allowed for values >38149 by the following: - */ - pm.maxpc16 = .005; /* I.e., 1/200% - 1/20000 */ - - /* Now parse the command line options. */ - while (--argc >= 1) - { - int catmore = 0; /* Set if the argument has an argument. */ - - /* Record each argument for posterity: */ - cp = safecat(command, sizeof command, cp, " "); - cp = safecat(command, sizeof command, cp, *++argv); - - if (strcmp(*argv, "-v") == 0) - pm.this.verbose = 1; - - else if (strcmp(*argv, "-l") == 0) - pm.log = 1; - - else if (strcmp(*argv, "-q") == 0) - summary = pm.this.verbose = pm.log = 0; - - else if (strcmp(*argv, "-w") == 0) - pm.this.treat_warnings_as_errors = 0; - - else if (strcmp(*argv, "--speed") == 0) - pm.this.speed = 1, pm.ngamma_tests = pm.ngammas, pm.test_standard = 0, - summary = 0; - - else if (strcmp(*argv, "--memory") == 0) - memstats = 1; - - else if (strcmp(*argv, "--size") == 0) - pm.test_size = 1; - - else if (strcmp(*argv, "--nosize") == 0) - pm.test_size = 0; - - else if (strcmp(*argv, "--standard") == 0) - pm.test_standard = 1; - - else if (strcmp(*argv, "--nostandard") == 0) - pm.test_standard = 0; - - else if (strcmp(*argv, "--transform") == 0) - pm.test_transform = 1; - - else if (strcmp(*argv, "--notransform") == 0) - pm.test_transform = 0; - -#ifdef PNG_READ_TRANSFORMS_SUPPORTED - else if (strncmp(*argv, "--transform-disable=", - sizeof "--transform-disable") == 0) - { - pm.test_transform = 1; - transform_disable(*argv + sizeof "--transform-disable"); - } - - else if (strncmp(*argv, "--transform-enable=", - sizeof "--transform-enable") == 0) - { - pm.test_transform = 1; - transform_enable(*argv + sizeof "--transform-enable"); - } -#endif /* PNG_READ_TRANSFORMS_SUPPORTED */ - - else if (strcmp(*argv, "--gamma") == 0) - { - /* Just do two gamma tests here (2.2 and linear) for speed: */ - pm.ngamma_tests = 2U; - pm.test_gamma_threshold = 1; - pm.test_gamma_transform = 1; - pm.test_gamma_sbit = 1; - pm.test_gamma_scale16 = 1; - pm.test_gamma_background = 1; - pm.test_gamma_alpha_mode = 1; - } - - else if (strcmp(*argv, "--nogamma") == 0) - pm.ngamma_tests = 0; - - else if (strcmp(*argv, "--gamma-threshold") == 0) - pm.ngamma_tests = 2U, pm.test_gamma_threshold = 1; - - else if (strcmp(*argv, "--nogamma-threshold") == 0) - pm.test_gamma_threshold = 0; - - else if (strcmp(*argv, "--gamma-transform") == 0) - pm.ngamma_tests = 2U, pm.test_gamma_transform = 1; - - else if (strcmp(*argv, "--nogamma-transform") == 0) - pm.test_gamma_transform = 0; - - else if (strcmp(*argv, "--gamma-sbit") == 0) - pm.ngamma_tests = 2U, pm.test_gamma_sbit = 1; - - else if (strcmp(*argv, "--nogamma-sbit") == 0) - pm.test_gamma_sbit = 0; - - else if (strcmp(*argv, "--gamma-16-to-8") == 0) - pm.ngamma_tests = 2U, pm.test_gamma_scale16 = 1; - - else if (strcmp(*argv, "--nogamma-16-to-8") == 0) - pm.test_gamma_scale16 = 0; - - else if (strcmp(*argv, "--gamma-background") == 0) - pm.ngamma_tests = 2U, pm.test_gamma_background = 1; - - else if (strcmp(*argv, "--nogamma-background") == 0) - pm.test_gamma_background = 0; - - else if (strcmp(*argv, "--gamma-alpha-mode") == 0) - pm.ngamma_tests = 2U, pm.test_gamma_alpha_mode = 1; - - else if (strcmp(*argv, "--nogamma-alpha-mode") == 0) - pm.test_gamma_alpha_mode = 0; - - else if (strcmp(*argv, "--expand16") == 0) - pm.test_gamma_expand16 = 1; - - else if (strcmp(*argv, "--noexpand16") == 0) - pm.test_gamma_expand16 = 0; - - else if (strcmp(*argv, "--more-gammas") == 0) - pm.ngamma_tests = 3U; - - else if (strcmp(*argv, "--all-gammas") == 0) - pm.ngamma_tests = pm.ngammas; - - else if (strcmp(*argv, "--progressive-read") == 0) - pm.this.progressive = 1; - - else if (strcmp(*argv, "--use-update-info") == 0) - ++pm.use_update_info; /* Can call multiple times */ - - else if (strcmp(*argv, "--interlace") == 0) - pm.interlace_type = PNG_INTERLACE_ADAM7; - - else if (strcmp(*argv, "--use-input-precision") == 0) - pm.use_input_precision = 1; - - else if (strcmp(*argv, "--calculations-use-input-precision") == 0) - pm.calculations_use_input_precision = 1; - - else if (strcmp(*argv, "--assume-16-bit-calculations") == 0) - pm.assume_16_bit_calculations = 1; - - else if (strcmp(*argv, "--calculations-follow-bit-depth") == 0) - pm.calculations_use_input_precision = - pm.assume_16_bit_calculations = 0; - - else if (strcmp(*argv, "--exhaustive") == 0) - pm.test_exhaustive = 1; - - else if (argc > 1 && strcmp(*argv, "--sbitlow") == 0) - --argc, pm.sbitlow = (png_byte)atoi(*++argv), catmore = 1; - - else if (argc > 1 && strcmp(*argv, "--touch") == 0) - --argc, touch = *++argv, catmore = 1; - - else if (argc > 1 && strncmp(*argv, "--max", 5) == 0) - { - --argc; - - if (strcmp(5+*argv, "abs8") == 0) - pm.maxabs8 = atof(*++argv); - - else if (strcmp(5+*argv, "abs16") == 0) - pm.maxabs16 = atof(*++argv); - - else if (strcmp(5+*argv, "calc8") == 0) - pm.maxcalc8 = atof(*++argv); - - else if (strcmp(5+*argv, "calc16") == 0) - pm.maxcalc16 = atof(*++argv); - - else if (strcmp(5+*argv, "out8") == 0) - pm.maxout8 = atof(*++argv); - - else if (strcmp(5+*argv, "out16") == 0) - pm.maxout16 = atof(*++argv); - - else if (strcmp(5+*argv, "pc8") == 0) - pm.maxpc8 = atof(*++argv); - - else if (strcmp(5+*argv, "pc16") == 0) - pm.maxpc16 = atof(*++argv); - - else - { - fprintf(stderr, "pngvalid: %s: unknown 'max' option\n", *argv); - exit(1); - } - - catmore = 1; - } - - else if (strcmp(*argv, "--log8") == 0) - --argc, pm.log8 = atof(*++argv), catmore = 1; - - else if (strcmp(*argv, "--log16") == 0) - --argc, pm.log16 = atof(*++argv), catmore = 1; - - else - { - fprintf(stderr, "pngvalid: %s: unknown argument\n", *argv); - exit(1); - } - - if (catmore) /* consumed an extra *argv */ - { - cp = safecat(command, sizeof command, cp, " "); - cp = safecat(command, sizeof command, cp, *argv); - } - } - - /* If pngvalid is run with no arguments default to a reasonable set of the - * tests. - */ - if (pm.test_standard == 0 && pm.test_size == 0 && pm.test_transform == 0 && - pm.ngamma_tests == 0) - { - /* Make this do all the tests done in the test shell scripts with the same - * parameters, where possible. The limitation is that all the progressive - * read and interlace stuff has to be done in separate runs, so only the - * basic 'standard' and 'size' tests are done. - */ - pm.test_standard = 1; - pm.test_size = 1; - pm.test_transform = 1; - pm.ngamma_tests = 2U; - } - - if (pm.ngamma_tests > 0 && - pm.test_gamma_threshold == 0 && pm.test_gamma_transform == 0 && - pm.test_gamma_sbit == 0 && pm.test_gamma_scale16 == 0 && - pm.test_gamma_background == 0 && pm.test_gamma_alpha_mode == 0) - { - pm.test_gamma_threshold = 1; - pm.test_gamma_transform = 1; - pm.test_gamma_sbit = 1; - pm.test_gamma_scale16 = 1; - pm.test_gamma_background = 1; - pm.test_gamma_alpha_mode = 1; - } - - else if (pm.ngamma_tests == 0) - { - /* Nothing to test so turn everything off: */ - pm.test_gamma_threshold = 0; - pm.test_gamma_transform = 0; - pm.test_gamma_sbit = 0; - pm.test_gamma_scale16 = 0; - pm.test_gamma_background = 0; - pm.test_gamma_alpha_mode = 0; - } - - Try - { - /* Make useful base images */ - make_transform_images(&pm.this); - - /* Perform the standard and gamma tests. */ - if (pm.test_standard) - { - perform_interlace_macro_validation(); - perform_formatting_test(&pm.this); - perform_standard_test(&pm); - perform_error_test(&pm); - } - - /* Various oddly sized images: */ - if (pm.test_size) - { - make_size_images(&pm.this); - perform_size_test(&pm); - } - -#ifdef PNG_READ_TRANSFORMS_SUPPORTED - /* Combinatorial transforms: */ - if (pm.test_transform) - perform_transform_test(&pm); -#endif /* PNG_READ_TRANSFORMS_SUPPORTED */ - -#ifdef PNG_READ_GAMMA_SUPPORTED - if (pm.ngamma_tests > 0) - perform_gamma_test(&pm, summary); -#endif - } - - Catch(fault) - { - fprintf(stderr, "pngvalid: test aborted (probably failed in cleanup)\n"); - if (!pm.this.verbose) - { - if (pm.this.error[0] != 0) - fprintf(stderr, "pngvalid: first error: %s\n", pm.this.error); - - fprintf(stderr, "pngvalid: run with -v to see what happened\n"); - } - exit(1); - } - - if (summary) - { - printf("%s: %s (%s point arithmetic)\n", - (pm.this.nerrors || (pm.this.treat_warnings_as_errors && - pm.this.nwarnings)) ? "FAIL" : "PASS", - command, -#if defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) || PNG_LIBPNG_VER < 10500 - "floating" -#else - "fixed" -#endif - ); - } - - if (memstats) - { - printf("Allocated memory statistics (in bytes):\n" - "\tread %lu maximum single, %lu peak, %lu total\n" - "\twrite %lu maximum single, %lu peak, %lu total\n", - (unsigned long)pm.this.read_memory_pool.max_max, - (unsigned long)pm.this.read_memory_pool.max_limit, - (unsigned long)pm.this.read_memory_pool.max_total, - (unsigned long)pm.this.write_memory_pool.max_max, - (unsigned long)pm.this.write_memory_pool.max_limit, - (unsigned long)pm.this.write_memory_pool.max_total); - } - - /* Do this here to provoke memory corruption errors in memory not directly - * allocated by libpng - not a complete test, but better than nothing. - */ - store_delete(&pm.this); - - /* Error exit if there are any errors, and maybe if there are any - * warnings. - */ - if (pm.this.nerrors || (pm.this.treat_warnings_as_errors && - pm.this.nwarnings)) - { - if (!pm.this.verbose) - fprintf(stderr, "pngvalid: %s\n", pm.this.error); - - fprintf(stderr, "pngvalid: %d errors, %d warnings\n", pm.this.nerrors, - pm.this.nwarnings); - - exit(1); - } - - /* Success case. */ - if (touch != NULL) - { - FILE *fsuccess = fopen(touch, "wt"); - - if (fsuccess != NULL) - { - int error = 0; - fprintf(fsuccess, "PNG validation succeeded\n"); - fflush(fsuccess); - error = ferror(fsuccess); - - if (fclose(fsuccess) || error) - { - fprintf(stderr, "%s: write failed\n", touch); - exit(1); - } - } - } - - return 0; -} diff -ru4NwbB libpng-1.5.6/pngwrite.c libpng-1.5.7rc01/pngwrite.c --- libpng-1.5.6/pngwrite.c 2011-11-02 22:42:50.547268135 -0500 +++ libpng-1.5.7rc01/pngwrite.c 2011-12-01 09:01:18.393111334 -0600 @@ -1,8 +1,8 @@ /* pngwrite.c - general routines to write a PNG file * - * Last changed in libpng 1.5.6 [(PENDING RELEASE)] + * Last changed in libpng 1.5.7 [(PENDING RELEASE)] * Copyright (c) 1998-2011 Glenn Randers-Pehrson * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) * @@ -489,10 +489,11 @@ #endif #ifdef PNG_SETJMP_SUPPORTED /* Applications that neglect to set up their own setjmp() and then - encounter a png_error() will longjmp here. Since the jmpbuf is - then meaningless we abort instead of returning. */ + * encounter a png_error() will longjmp here. Since the jmpbuf is + * then meaningless we abort instead of returning. + */ #ifdef USE_FAR_KEYWORD if (setjmp(tmp_jmpbuf)) #else if (setjmp(png_jmpbuf(png_ptr))) /* sets longjmp to match setjmp */ diff -ru4NwbB libpng-1.5.6/pngwtran.c libpng-1.5.7rc01/pngwtran.c --- libpng-1.5.6/pngwtran.c 2011-11-02 22:42:50.554047247 -0500 +++ libpng-1.5.7rc01/pngwtran.c 2011-12-01 09:01:18.400210604 -0600 @@ -1,8 +1,8 @@ /* pngwtran.c - transforms the data in a row for PNG writers * - * Last changed in libpng 1.5.6 [(PENDING RELEASE)] + * Last changed in libpng 1.5.6 [November 3, 2011] * Copyright (c) 1998-2011 Glenn Randers-Pehrson * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) * diff -ru4NwbB libpng-1.5.6/pngwutil.c libpng-1.5.7rc01/pngwutil.c --- libpng-1.5.6/pngwutil.c 2011-11-02 22:42:50.567056497 -0500 +++ libpng-1.5.7rc01/pngwutil.c 2011-12-01 09:01:18.413363946 -0600 @@ -1,8 +1,8 @@ /* pngwutil.c - utilities to write a PNG file * - * Last changed in libpng 1.5.6 [(PENDING RELEASE)] + * Last changed in libpng 1.5.6 [November 3, 2011] * Copyright (c) 1998-2011 Glenn Randers-Pehrson * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) * diff -ru4NwbB libpng-1.5.6/projects/owatcom/libpng.wpj libpng-1.5.7rc01/projects/owatcom/libpng.wpj --- libpng-1.5.6/projects/owatcom/libpng.wpj 2011-06-11 06:32:45.000000000 -0500 +++ libpng-1.5.7rc01/projects/owatcom/libpng.wpj 2011-11-23 09:00:02.962504000 -0600 @@ -4,11 +4,11 @@ VpeMain 1 WRect 256 -146 -8966 -9303 +0 +8960 +9284 2 MProject 3 MCommand @@ -46,10 +46,10 @@ 10 WRect 0 0 -5644 -4183 +5632 +4164 0 0 11 WFileName @@ -61,11 +61,11 @@ VComponent 13 WRect 1280 -1560 -5644 -4183 +1540 +5632 +4164 0 0 14 WFileName @@ -76,12 +76,12 @@ 15 VComponent 16 WRect -530 -507 -5644 -4183 +518 +487 +5632 +4164 0 0 17 WFileName diff -ru4NwbB libpng-1.5.6/projects/owatcom/pngconfig.mak libpng-1.5.7rc01/projects/owatcom/pngconfig.mak --- libpng-1.5.6/projects/owatcom/pngconfig.mak 2011-06-11 06:11:41.000000000 -0500 +++ libpng-1.5.7rc01/projects/owatcom/pngconfig.mak 2011-11-08 19:12:49.511653000 -0600 @@ -56,11 +56,11 @@ instructions consult and edit projects/openwatcom/pngconfig.dfa << $(DELETE) dfn.c dfn1.out dfn2.out -pnglibconf.dfn: ..\..\scripts\pnglibconf.dfa ..\..\scripts\options.awk pngconfig.dfa +pnglibconf.dfn: ..\..\scripts\pnglibconf.dfa ..\..\scripts\options.awk pngconfig.dfa ..\..\pngconf.h $(DELETE) $@ dfn1.out dfn2.out - $(AWK) -f ..\..\scripts\options.awk out=dfn1.out ..\..\scripts\pnglibconf.dfa pngconfig.dfa $(DFA_XTRA) 1>&2 + $(AWK) -f ..\..\scripts\options.awk out=dfn1.out version=search ..\..\pngconf.h ..\..\scripts\pnglibconf.dfa pngconfig.dfa $(DFA_XTRA) 1>&2 $(AWK) -f ..\..\scripts\options.awk out=dfn2.out dfn1.out 1>&2 $(COPY) dfn2.out $@ $(DELETE) dfn1.out dfn2.out diff -ru4NwbB libpng-1.5.6/projects/vstudio/pngvalid/pngvalid.vcxproj libpng-1.5.7rc01/projects/vstudio/pngvalid/pngvalid.vcxproj --- libpng-1.5.6/projects/vstudio/pngvalid/pngvalid.vcxproj 2011-11-02 22:42:52.845365823 -0500 +++ libpng-1.5.7rc01/projects/vstudio/pngvalid/pngvalid.vcxproj 2011-12-01 09:01:20.864436650 -0600 @@ -203,9 +203,8 @@ UseLinkTimeCodeGeneration Executing PNG validation program - $(OutDir)pngvalid.exe ..\..\..\pngvalid.png $(IntDir)pngout.png "$(OutDir)pngvalid.exe" --touch "$(IntDir)pngvalid.out" $(IntDir)pngvalid.out $(OutDir)pngvalid.exe diff -ru4NwbB libpng-1.5.6/projects/vstudio/vstudio.sln libpng-1.5.7rc01/projects/vstudio/vstudio.sln --- libpng-1.5.6/projects/vstudio/vstudio.sln 2010-08-24 15:04:11.000000000 -0500 +++ libpng-1.5.7rc01/projects/vstudio/vstudio.sln 2011-11-23 09:00:02.985074000 -0600 @@ -1,24 +1,24 @@ Microsoft Visual Studio Solution File, Format Version 11.00 # Visual Studio 2010 Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "libpng", "libpng\libpng.vcxproj", "{D6973076-9317-4EF2-A0B8-B7A18AC0713E}" ProjectSection(ProjectDependencies) = postProject - {64CE4900-97EA-2DD5-4226-F2E36FFF2867} = {64CE4900-97EA-2DD5-4226-F2E36FFF2867} + {60F89955-91C6-3A36-8000-13C592FEC2DF} = {60F89955-91C6-3A36-8000-13C592FEC2DF} {EB33566E-DA7F-4D28-9077-88C0B7C77E35} = {EB33566E-DA7F-4D28-9077-88C0B7C77E35} EndProjectSection EndProject Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "pngtest", "pngtest\pngtest.vcxproj", "{228BA965-50D5-42B2-8BCF-AFCC227E3C1D}" ProjectSection(ProjectDependencies) = postProject - {64CE4900-97EA-2DD5-4226-F2E36FFF2867} = {64CE4900-97EA-2DD5-4226-F2E36FFF2867} + {60F89955-91C6-3A36-8000-13C592FEC2DF} = {60F89955-91C6-3A36-8000-13C592FEC2DF} {EB33566E-DA7F-4D28-9077-88C0B7C77E35} = {EB33566E-DA7F-4D28-9077-88C0B7C77E35} {D6973076-9317-4EF2-A0B8-B7A18AC0713E} = {D6973076-9317-4EF2-A0B8-B7A18AC0713E} EndProjectSection EndProject -Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "zlib", "zlib\zlib.vcxproj", "{64CE4900-97EA-2DD5-4226-F2E36FFF2867}" +Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "zlib", "zlib\zlib.vcxproj", "{60F89955-91C6-3A36-8000-13C592FEC2DF}" EndProject Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "pngvalid", "pngvalid\pngvalid.vcxproj", "{9B36B6FE-7FC0-434F-A71F-BBEF8099F1D8}" ProjectSection(ProjectDependencies) = postProject - {64CE4900-97EA-2DD5-4226-F2E36FFF2867} = {64CE4900-97EA-2DD5-4226-F2E36FFF2867} + {60F89955-91C6-3A36-8000-13C592FEC2DF} = {60F89955-91C6-3A36-8000-13C592FEC2DF} {EB33566E-DA7F-4D28-9077-88C0B7C77E35} = {EB33566E-DA7F-4D28-9077-88C0B7C77E35} {D6973076-9317-4EF2-A0B8-B7A18AC0713E} = {D6973076-9317-4EF2-A0B8-B7A18AC0713E} EndProjectSection EndProject @@ -47,16 +47,16 @@ {228BA965-50D5-42B2-8BCF-AFCC227E3C1D}.Release Library|Win32.ActiveCfg = Release Library|Win32 {228BA965-50D5-42B2-8BCF-AFCC227E3C1D}.Release Library|Win32.Build.0 = Release Library|Win32 {228BA965-50D5-42B2-8BCF-AFCC227E3C1D}.Release|Win32.ActiveCfg = Release|Win32 {228BA965-50D5-42B2-8BCF-AFCC227E3C1D}.Release|Win32.Build.0 = Release|Win32 - {64CE4900-97EA-2DD5-4226-F2E36FFF2867}.Debug Library|Win32.ActiveCfg = Debug Library|Win32 - {64CE4900-97EA-2DD5-4226-F2E36FFF2867}.Debug Library|Win32.Build.0 = Debug Library|Win32 - {64CE4900-97EA-2DD5-4226-F2E36FFF2867}.Debug|Win32.ActiveCfg = Debug|Win32 - {64CE4900-97EA-2DD5-4226-F2E36FFF2867}.Debug|Win32.Build.0 = Debug|Win32 - {64CE4900-97EA-2DD5-4226-F2E36FFF2867}.Release Library|Win32.ActiveCfg = Release Library|Win32 - {64CE4900-97EA-2DD5-4226-F2E36FFF2867}.Release Library|Win32.Build.0 = Release Library|Win32 - {64CE4900-97EA-2DD5-4226-F2E36FFF2867}.Release|Win32.ActiveCfg = Release|Win32 - {64CE4900-97EA-2DD5-4226-F2E36FFF2867}.Release|Win32.Build.0 = Release|Win32 + {60F89955-91C6-3A36-8000-13C592FEC2DF}.Debug Library|Win32.ActiveCfg = Debug Library|Win32 + {60F89955-91C6-3A36-8000-13C592FEC2DF}.Debug Library|Win32.Build.0 = Debug Library|Win32 + {60F89955-91C6-3A36-8000-13C592FEC2DF}.Debug|Win32.ActiveCfg = Debug|Win32 + {60F89955-91C6-3A36-8000-13C592FEC2DF}.Debug|Win32.Build.0 = Debug|Win32 + {60F89955-91C6-3A36-8000-13C592FEC2DF}.Release Library|Win32.ActiveCfg = Release Library|Win32 + {60F89955-91C6-3A36-8000-13C592FEC2DF}.Release Library|Win32.Build.0 = Release Library|Win32 + {60F89955-91C6-3A36-8000-13C592FEC2DF}.Release|Win32.ActiveCfg = Release|Win32 + {60F89955-91C6-3A36-8000-13C592FEC2DF}.Release|Win32.Build.0 = Release|Win32 {9B36B6FE-7FC0-434F-A71F-BBEF8099F1D8}.Debug Library|Win32.ActiveCfg = Debug Library|Win32 {9B36B6FE-7FC0-434F-A71F-BBEF8099F1D8}.Debug Library|Win32.Build.0 = Debug Library|Win32 {9B36B6FE-7FC0-434F-A71F-BBEF8099F1D8}.Debug|Win32.ActiveCfg = Debug|Win32 {9B36B6FE-7FC0-434F-A71F-BBEF8099F1D8}.Debug|Win32.Build.0 = Debug|Win32 @@ -71,8 +71,16 @@ {EB33566E-DA7F-4D28-9077-88C0B7C77E35}.Release Library|Win32.ActiveCfg = Release|Win32 {EB33566E-DA7F-4D28-9077-88C0B7C77E35}.Release Library|Win32.Build.0 = Release|Win32 {EB33566E-DA7F-4D28-9077-88C0B7C77E35}.Release|Win32.ActiveCfg = Release|Win32 {EB33566E-DA7F-4D28-9077-88C0B7C77E35}.Release|Win32.Build.0 = Release|Win32 + {277AC57F-313B-4D06-B119-A3CDB672D2FF}.Debug Library|Win32.ActiveCfg = Debug Library|Win32 + {277AC57F-313B-4D06-B119-A3CDB672D2FF}.Debug Library|Win32.Build.0 = Debug Library|Win32 + {277AC57F-313B-4D06-B119-A3CDB672D2FF}.Debug|Win32.ActiveCfg = Debug|Win32 + {277AC57F-313B-4D06-B119-A3CDB672D2FF}.Debug|Win32.Build.0 = Debug|Win32 + {277AC57F-313B-4D06-B119-A3CDB672D2FF}.Release Library|Win32.ActiveCfg = Release Library|Win32 + {277AC57F-313B-4D06-B119-A3CDB672D2FF}.Release Library|Win32.Build.0 = Release Library|Win32 + {277AC57F-313B-4D06-B119-A3CDB672D2FF}.Release|Win32.ActiveCfg = Release|Win32 + {277AC57F-313B-4D06-B119-A3CDB672D2FF}.Release|Win32.Build.0 = Release|Win32 EndGlobalSection GlobalSection(SolutionProperties) = preSolution HideSolutionNode = FALSE EndGlobalSection diff -ru4NwbB libpng-1.5.6/scripts/def.dfn libpng-1.5.7rc01/scripts/def.dfn --- libpng-1.5.6/scripts/def.dfn 2011-01-04 09:45:35.000000000 -0600 +++ libpng-1.5.7rc01/scripts/def.dfn 2011-11-03 16:13:57.945898000 -0500 @@ -26,13 +26,13 @@ S--E S-EXPORTS-E S-;Version 1.5.0beta58-E -/* NOTE: @@@ is interpreted by the calling script as a signal to +/* NOTE: PNG_JOIN is interpreted by the calling script as a signal to * join the two things on either side, so we can do symbol * substitution within the name, regular C ## joins the pp-tokens, * not their final values. */ #define PNG_EXPORTA(ordinal, type, name, args, attributes)\ - PNG_DEFN_MAGIC- SYMBOL_PREFIX @@@ name-PNG_DEFN_END + PNG_DEFN_MAGIC- SYMBOL_PREFIX PNG_JOIN name-PNG_DEFN_END #include "../png.h" diff -ru4NwbB libpng-1.5.6/scripts/makefile.std libpng-1.5.7rc01/scripts/makefile.std --- libpng-1.5.6/scripts/makefile.std 2011-11-02 22:42:52.714325462 -0500 +++ libpng-1.5.7rc01/scripts/makefile.std 2011-12-01 09:01:20.697768817 -0600 @@ -49,11 +49,11 @@ all: libpng.a pngtest # The standard pnglibconf.h exists as scripts/pnglibconf.h.prebuilt, # copy this if the following doesn't work. -pnglibconf.dfn: scripts/pnglibconf.dfa scripts/options.awk +pnglibconf.dfn: scripts/pnglibconf.dfa scripts/options.awk pngconf.h $(RM_F) $@ dfn?.out - $(AWK) -f scripts/options.awk out=dfn1.out\ + $(AWK) -f scripts/options.awk out=dfn1.out version=search pngconf.h\ scripts/pnglibconf.dfa $(DFA_XTRA) 1>&2 $(AWK) -f scripts/options.awk out=dfn2.out dfn1.out 1>&2 cp dfn2.out $@ $(RM_F) dfn?.out @@ -61,11 +61,11 @@ pnglibconf.h: pnglibconf.dfn $(RM_F) $@ dfn.c dfn?.out $(ECHO) '#include "pnglibconf.dfn"' >dfn.c $(CPP) $(DFNFLAGS) dfn.c >dfn1.out - $(SED) -n -e 's|^.*PNG_DEFN_MAGIC-\(.*\)-PNG_DEFN_END.*$$|\1|p'\ + $(SED) -n -e 's|^.*PNG_DEFN_MAGIC *-\(.*\)- *PNG_DEFN_END.*$$|\1|p'\ dfn1.out >dfn2.out - $(SED) -e 's| *@@@ *||g' -e 's| *$$||' dfn2.out >dfn3.out + $(SED) -e 's| *PNG_JOIN *||g' -e 's| *$$||' dfn2.out >dfn3.out cp dfn3.out $@ $(RM_F) dfn.c dfn?.out libpng.a: $(OBJS) diff -ru4NwbB libpng-1.5.6/scripts/options.awk libpng-1.5.7rc01/scripts/options.awk --- libpng-1.5.6/scripts/options.awk 2011-05-07 10:30:44.000000000 -0500 +++ libpng-1.5.7rc01/scripts/options.awk 2011-12-01 09:01:20.760974998 -0600 @@ -1,8 +1,8 @@ #!/bin/awk -f # scripts/options.awk - library build configuration control # -# last changed in libpng version 1.5.0 - January 6, 2011 +# last changed in libpng version 1.5.7 - (PENDING RELEASE) # # Copyright (c) 1998-2011 Glenn Randers-Pehrson # # This code is released under the libpng license. @@ -31,18 +31,21 @@ BEGIN{ out="/dev/null" # intermediate, preprocessed, file pre=-1 # preprocess (first line) + version="libpng version unknown" # version information + version_file="" # where to find the version err=0 # in-line exit sets this start="PNG_DEFN_MAGIC-" # Arbitrary start end="-PNG_DEFN_END" # Arbitrary end - cx= "/@@@*" # Open C comment for output file + ct="PNG_JOIN" # Join two tokens + cx= "/" ct "*" # Open C comment for output file comment=start cx # Comment start cend="*/" end # Comment end - def=start "#define PNG_@@@" # Arbitrary define - sup="@@@_SUPPORTED" end # end supported option - und=comment "#undef PNG_@@@" # Unsupported option - une="@@@_SUPPORTED" cend # end unsupported option + def=start "#define PNG_" ct # Arbitrary define + sup=ct "_SUPPORTED" end # end supported option + und=comment "#undef PNG_" ct # Unsupported option + une=ct "_SUPPORTED" cend # end unsupported option error=start "ERROR:" # error message # Variables deb=0 # debug - set on command line @@ -84,8 +87,30 @@ # And fall through to continue processing } } +# While pre-processing if version is set to "search" look for a version string +# in the following file. +pre && version == "search" && version_file == ""{ + version_file = FILENAME +} + +pre && version == "search" && version_file != FILENAME{ + print "version string not found in", version_file + err = 1 + exit 1 +} + +pre && version == "search" && $0 ~ /^ \* libpng version/{ + version = substr($0, 4) + print "version =", version >out + next +} + +pre && FILENAME == version_file{ + next +} + # variable=value # Sets the given variable to the given value (the syntax is fairly # free form, except for deb (you are expected to understand how to # set the debug variable...) @@ -93,8 +118,13 @@ # This happens before the check on 'pre' below skips most of the # rest of the actions, so the variable settings happen during # preprocessing but are recorded in the END action too. This # allows them to be set on the command line too. +$0 ~ /^[ ]*version[ ]*=/{ + sub(/^[ ]*version[ ]*=[ ]*/, "") + version = $0 + next +} $0 ~ /^[ ]*everything[ =]*off[ ]*$/{ everything = "off" next } @@ -164,8 +194,21 @@ print start end >out next } +# version +# Inserts a version comment +$1 == "version" && NF == 1{ + if (version == "") { + print "ERROR: no version string set" + err = 1 # prevent END{} running + exit 1 + } + + print comment, version, cend >out + next +} + # file output input protect # Informational: the official name of the input file (without # make generated local directories), the official name of the # output file and, if required, a name to use in a protection diff -ru4NwbB libpng-1.5.6/scripts/pnglibconf.dfa libpng-1.5.7rc01/scripts/pnglibconf.dfa --- libpng-1.5.6/scripts/pnglibconf.dfa 2011-10-13 19:32:21.681776000 -0500 +++ libpng-1.5.7rc01/scripts/pnglibconf.dfa 2011-11-23 09:00:02.993429000 -0600 @@ -5,9 +5,9 @@ @ */ # com pnglibconf.h - library build configuration com -com libpng version 1.5.3 - July 7, 2011 +version com com Copyright (c) 1998-2011 Glenn Randers-Pehrson com com This code is released under the libpng license. diff -ru4NwbB libpng-1.5.6/scripts/pnglibconf.h.prebuilt libpng-1.5.7rc01/scripts/pnglibconf.h.prebuilt --- libpng-1.5.6/scripts/pnglibconf.h.prebuilt 2011-10-13 19:32:27.985999000 -0500 +++ libpng-1.5.7rc01/scripts/pnglibconf.h.prebuilt 2011-12-01 09:01:20.773115354 -0600 @@ -2,9 +2,9 @@ /* libpng STANDARD API DEFINITION */ /* pnglibconf.h - library build configuration */ -/* libpng version 1.5.4 - last changed on June 22, 2011 */ +/* Libpng 1.5.7rc01 - December 1, 2011 */ /* Copyright (c) 1998-2011 Glenn Randers-Pehrson */ /* This code is released under the libpng license. */ @@ -53,8 +53,10 @@ #define PNG_ERROR_TEXT_SUPPORTED #define PNG_FIXED_POINT_SUPPORTED #define PNG_FLOATING_ARITHMETIC_SUPPORTED #define PNG_FLOATING_POINT_SUPPORTED +#define PNG_FORMAT_AFIRST_SUPPORTED +#define PNG_FORMAT_BGR_SUPPORTED #define PNG_gAMA_SUPPORTED #define PNG_HANDLE_AS_UNKNOWN_SUPPORTED #define PNG_hIST_SUPPORTED #define PNG_iCCP_SUPPORTED diff -ru4NwbB libpng-1.5.6/scripts/pnglibconf.mak libpng-1.5.7rc01/scripts/pnglibconf.mak --- libpng-1.5.6/scripts/pnglibconf.mak 2011-05-07 10:31:01.000000000 -0500 +++ libpng-1.5.7rc01/scripts/pnglibconf.mak 2011-11-08 19:12:49.536424000 -0600 @@ -34,20 +34,21 @@ $(DELETE) $@ dfn.c dfn1.out dfn2.out dfn3.out $(ECHO) '#include "pnglibconf.dfn"' >dfn.c $(CPP) $(DFNFLAGS) dfn.c >dfn1.out $(ECHO) "If 'cpp -e' crashes try /lib/cpp (e.g. CPP='/lib/cpp')" >&2 - $(SED) -n -e 's|^.*PNG_DEFN_MAGIC-\(.*\)-PNG_DEFN_END.*$$|\1|p'\ + $(SED) -n -e 's|^.*PNG_DEFN_MAGIC *-\(.*\)- *PNG_DEFN_END.*$$|\1|p'\ dfn1.out >dfn2.out - $(SED) -e 's| *@@@ *||g' -e 's| *$$||' dfn2.out >dfn3.out + $(SED) -e 's| *PNG_JOIN *||g' -e 's| *$$||' dfn2.out >dfn3.out $(COPY) dfn3.out $@ $(DELETE) dfn.c dfn1.out dfn2.out dfn3.out -pnglibconf.dfn: $(srcdir)/scripts/pnglibconf.dfa $(srcdir)/scripts/options.awk +pnglibconf.dfn: $(srcdir)/scripts/pnglibconf.dfa $(srcdir)/scripts/options.awk $(srcdir)/pngconf.h $(DELETE) $@ dfn1.out dfn2.out $(ECHO) "Calling $(AWK) from scripts/pnglibconf.mak" >&2 $(ECHO) "If 'awk' crashes try a better awk (e.g. AWK='nawk')" >&2 - $(AWK) -f $(srcdir)/scripts/options.awk out=dfn1.out\ - $(srcdir)/scripts/pnglibconf.dfa $(DFA_XTRA) 1>&2 + $(AWK) -f $(srcdir)/scripts/options.awk out=dfn1.out version=search\ + $(srcdir)/pngconf.h $(srcdir)/scripts/pnglibconf.dfa\ + $(DFA_XTRA) 1>&2 $(AWK) -f $(srcdir)/scripts/options.awk out=dfn2.out dfn1.out 1>&2 $(COPY) dfn2.out $@ $(DELETE) dfn1.out dfn2.out diff -ru4NwbB libpng-1.5.6/scripts/sym.dfn libpng-1.5.7rc01/scripts/sym.dfn --- libpng-1.5.6/scripts/sym.dfn 2011-01-21 19:20:38.000000000 -0600 +++ libpng-1.5.7rc01/scripts/sym.dfn 2011-11-03 16:13:57.962584000 -0500 @@ -9,7 +9,7 @@ * and license in png.h */ #define PNG_EXPORTA(ordinal, type, name, args, attributes)\ - PNG_DEFN_MAGIC-SYMBOL_PREFIX @@@ name-PNG_DEFN_END + PNG_DEFN_MAGIC-SYMBOL_PREFIX PNG_JOIN name-PNG_DEFN_END #include "../png.h" diff -ru4NwbB libpng-1.5.6/scripts/vers.dfn libpng-1.5.7rc01/scripts/vers.dfn --- libpng-1.5.6/scripts/vers.dfn 2011-01-21 19:20:50.000000000 -0600 +++ libpng-1.5.7rc01/scripts/vers.dfn 2011-11-03 16:13:57.969672000 -0500 @@ -10,15 +10,15 @@ */ #define HEADER PNG_DEFN_MAGIC-PNGLIB_LIBNAME {global:-PNG_DEFN_END -/* NOTE: @@@ is interpreted by the calling script as a signal to +/* NOTE: PNG_JOIN is interpreted by the calling script as a signal to * join the two things on either side, so we can do symbol * substitution within the name, regular C ## joins the pp-tokens, * not their final values. */ #define PNG_EXPORTA(ordinal, type, name, args, attributes)\ - PNG_DEFN_MAGIC- SYMBOL_PREFIX @@@ name;-PNG_DEFN_END + PNG_DEFN_MAGIC- SYMBOL_PREFIX PNG_JOIN name;-PNG_DEFN_END #define TRAILER PNG_DEFN_MAGIC-local: *; };-PNG_DEFN_END HEADER