diff -ru4NwbB libpng-1.6.0beta33/arm/arm_init.c libpng-1.7.0alpha02/arm/arm_init.c --- libpng-1.6.0beta33/arm/arm_init.c 2012-12-15 07:25:15.067576000 -0600 +++ libpng-1.7.0alpha02/arm/arm_init.c 2012-12-15 20:42:25.107421000 -0600 @@ -2,9 +2,9 @@ /* arm_init.c - NEON optimised filter functions * * Copyright (c) 2012 Glenn Randers-Pehrson * Written by Mans Rullgard, 2011. - * Last changed in libpng 1.5.14 [(PENDING RELEASE)] + * Last changed in libpng 1.6.0 [(PENDING RELEASE)] * * This code is released under the libpng license. * For conditions of distribution and use, see the disclaimer * and license in png.h @@ -42,9 +42,9 @@ } #endif /* __linux__ && __arm__ */ void -png_init_filter_functions_neon(png_structp pp, unsigned int bpp) +png_init_filter_functions_neon(png_structrp pp, unsigned int bpp) { #ifdef __arm__ #ifdef __linux__ if (!png_have_hwcap(HWCAP_NEON)) diff -ru4NwbB libpng-1.6.0beta33/configure.ac libpng-1.7.0alpha02/configure.ac --- libpng-1.6.0beta33/configure.ac 2012-12-15 08:22:45.407827842 -0600 +++ libpng-1.7.0alpha02/configure.ac 2012-12-16 19:28:07.970316311 -0600 @@ -38,9 +38,9 @@ dnl stop configure from automagically running automake PNGLIB_VERSION=1.7.0alpha02 PNGLIB_MAJOR=1 -PNGLIB_MINOR=6 +PNGLIB_MINOR=7 PNGLIB_RELEASE=%RELEASE% dnl End of version number stuff diff -ru4NwbB libpng-1.6.0beta33/contrib/gregbook/Makefile.sgi libpng-1.7.0alpha02/contrib/gregbook/Makefile.sgi --- libpng-1.6.0beta33/contrib/gregbook/Makefile.sgi 2012-12-15 08:22:35.264896311 -0600 +++ libpng-1.7.0alpha02/contrib/gregbook/Makefile.sgi 2012-12-16 19:27:56.015956121 -0600 @@ -22,11 +22,11 @@ # macros -------------------------------------------------------------------- -PNGINC = -I/usr/local/include/libpng16 -PNGLIB = -L/usr/local/lib -lpng16 # dynamically linked against libpng -#PNGLIB = /usr/local/lib/libpng16.a # statically linked against libpng +PNGINC = -I/usr/local/include/libpng17 +PNGLIB = -L/usr/local/lib -lpng17 # dynamically linked against libpng +#PNGLIB = /usr/local/lib/libpng17.a # statically linked against libpng # or: #PNGINC = -I../.. #PNGLIB = -L../.. -lpng #PNGLIB = ../../libpng.a diff -ru4NwbB libpng-1.6.0beta33/contrib/gregbook/Makefile.unx libpng-1.7.0alpha02/contrib/gregbook/Makefile.unx --- libpng-1.6.0beta33/contrib/gregbook/Makefile.unx 2012-12-15 08:22:35.275834871 -0600 +++ libpng-1.7.0alpha02/contrib/gregbook/Makefile.unx 2012-12-16 19:27:56.026268516 -0600 @@ -25,16 +25,16 @@ # macros -------------------------------------------------------------------- #PNGDIR = /usr/local/lib -#PNGINC = -I/usr/local/include/libpng16 -#PNGLIBd = -L$(PNGDIR) -lpng16 # dynamically linked, installed libpng -#PNGLIBs = $(PNGDIR)/libpng16.a # statically linked, installed libpng +#PNGINC = -I/usr/local/include/libpng17 +#PNGLIBd = -L$(PNGDIR) -lpng17 # dynamically linked, installed libpng +#PNGLIBs = $(PNGDIR)/libpng17.a # statically linked, installed libpng # or: PNGDIR = ../..# this one is for libpng-x.y.z/contrib/gregbook builds #PNGDIR = ../libpng PNGINC = -I$(PNGDIR) -PNGLIBd = -Wl,-rpath,$(PNGDIR) -L$(PNGDIR) -lpng16 # dynamically linked +PNGLIBd = -Wl,-rpath,$(PNGDIR) -L$(PNGDIR) -lpng17 # dynamically linked PNGLIBs = $(PNGDIR)/libpng.a # statically linked, local libpng ZDIR = /usr/local/lib #ZDIR = /usr/lib64 diff -ru4NwbB libpng-1.6.0beta33/contrib/libtests/pngvalid.c libpng-1.7.0alpha02/contrib/libtests/pngvalid.c --- libpng-1.6.0beta33/contrib/libtests/pngvalid.c 2012-12-15 08:22:37.833553322 -0600 +++ libpng-1.7.0alpha02/contrib/libtests/pngvalid.c 2012-12-16 19:27:58.688157489 -0600 @@ -343,13 +343,18 @@ #define PALETTE_COUNT(bit_depth) ((bit_depth) > 4 ? 1U : 16U) static int next_format(png_bytep colour_type, png_bytep bit_depth, - unsigned int* palette_number) + unsigned int* palette_number, int no_low_depth_gray) { if (*bit_depth == 0) { - *colour_type = 0, *bit_depth = 1, *palette_number = 0; + *colour_type = 0; + if (no_low_depth_gray) + *bit_depth = 8; + else + *bit_depth = 1; + *palette_number = 0; return 1; } if (*colour_type == 3) @@ -1827,8 +1832,9 @@ 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 maxcalcG; /* 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 @@ -1866,12 +1872,17 @@ /* Run the odd-sized image and interlace read/write tests? */ unsigned int test_size :1; - /* Run tests on reading with a combiniation of transforms, */ + /* Run tests on reading with a combination of transforms, */ unsigned int test_transform :1; - /* When to use the use_input_precision option: */ + /* When to use the use_input_precision option, this controls the gamma + * validation code checks. If set any value that is within the transformed + * range input-.5 to input+.5 will be accepted, otherwise the value must be + * within the normal limits. It should not be necessary to set this; the + * result should always be exact within the permitted error limits. + */ unsigned int use_input_precision :1; unsigned int use_input_precision_sbit :1; unsigned int use_input_precision_16to8 :1; @@ -1879,10 +1890,10 @@ * 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. + /* If set assume that the calculations are done in 16 bits even if the sample + * depth is 8 bits. */ unsigned int assume_16_bit_calculations :1; /* Which gamma tests to run: */ @@ -1935,8 +1946,9 @@ 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->maxcalcG = 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; @@ -1949,8 +1961,9 @@ pm->use_input_precision = 0; pm->use_input_precision_sbit = 0; pm->use_input_precision_16to8 = 0; pm->calculations_use_input_precision = 0; + pm->assume_16_bit_calculations = 0; pm->test_gamma_threshold = 0; pm->test_gamma_transform = 0; pm->test_gamma_sbit = 0; pm->test_gamma_scale16 = 0; @@ -1963,28 +1976,35 @@ /* Rely on the memset for all the other fields - there are no pointers */ } #ifdef PNG_READ_TRANSFORMS_SUPPORTED + +/* This controls use of checks that explicitly know how libpng digitizes the + * samples in calculations; setting this circumvents simple error limit checking + * in the rgb_to_gray check, replacing it with an exact copy of the libpng 1.5 + * algorithm. + */ +#define DIGITIZE PNG_LIBPNG_VER < 10700 + /* 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. + * with the precision of the input, not the precision of the output depth. * * 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. */ #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED -static double digitize(PNG_CONST png_modifier *pm, double value, - int sample_depth, int do_round) +#if DIGITIZE +static double digitize(double value, int 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; + PNG_CONST unsigned int digitization_factor = (1U << depth) -1; /* 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. */ @@ -1997,33 +2018,32 @@ if (do_round) value += .5; return floor(value)/digitization_factor; } #endif +#endif /* RGB_TO_GRAY */ -#if (defined PNG_READ_GAMMA_SUPPORTED) ||\ - (defined PNG_READ_RGB_TO_GRAY_SUPPORTED) +#ifdef PNG_READ_GAMMA_SUPPORTED 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))) + if (pm->assume_16_bit_calculations || + (pm->calculations_use_input_precision ? in_depth : out_depth) == 16) return pm->maxabs16; else return pm->maxabs8; } -#endif -#ifdef PNG_READ_GAMMA_SUPPORTED 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))) + if ((pm->calculations_use_input_precision ? in_depth : out_depth) == 16) return pm->maxcalc16; + else if (pm->assume_16_bit_calculations) + return pm->maxcalcG; else return pm->maxcalc8; } @@ -2031,10 +2051,10 @@ { /* 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))) + if (pm->assume_16_bit_calculations || + (pm->calculations_use_input_precision ? in_depth : out_depth) == 16) return pm->maxpc16 * .01; else return pm->maxpc8 * .01; } @@ -2064,10 +2084,9 @@ if (out_depth == 4) return .90644-.5; - if (out_depth == 16 && (in_depth == 16 || - !pm->calculations_use_input_precision)) + if ((pm->calculations_use_input_precision ? in_depth : out_depth) == 16) return pm->maxout16; /* This is the case where the value was calculated at 8-bit precision then * scaled to 16 bits. @@ -2098,10 +2117,9 @@ return pm->log8; } - if (out_depth == 16 && (in_depth == 16 || - !pm->calculations_use_input_precision)) + if ((pm->calculations_use_input_precision ? in_depth : out_depth) == 16) { if (pm->log16 == 0) return 65536; @@ -2124,10 +2142,10 @@ */ 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) + if (out_depth == 16 && in_depth != 16 && + pm->calculations_use_input_precision) return 257; else return 1; } @@ -3472,9 +3490,9 @@ /* 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)) + while (next_format(&colour_type, &bit_depth, &palette_number, 0)) { int interlace_type; for (interlace_type = PNG_INTERLACE_NONE; @@ -5783,14 +5801,11 @@ 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. + /* use-input-precision 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. */ if (in_ct == PNG_COLOR_TYPE_PALETTE || in_bd < 16) in_sample_depth = 8; else @@ -5799,9 +5814,10 @@ 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 calculations are at 8 bit precision, and the output actually + * consists of scaled 8-bit values, so scale .5 in 8 bits to the 16 bits: */ else digitization_error = .5 * 257; } @@ -6615,12 +6631,25 @@ 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); + /* The computations have the form: + * + * r * rc + g * gc + b * bc + * + * Each component of which is +/-1/65535 from the gamma_to_1 table + * lookup, resulting in a base error of +/-6. The gamma_from_1 + * conversion adds another +/-2 in the 16-bit case and + * +/-(1<<(15-PNG_MAX_GAMMA_8)) in the 8-bit case. + */ + that->pm->limit += pow( +# if PNG_MAX_GAMMA_8 < 14 + (that->this.bit_depth == 16 ? 8. : + 6. + (1<<(15-PNG_MAX_GAMMA_8))) +# else + 8. +# endif + /65535, data.gamma); } else { @@ -6636,9 +6665,9 @@ { /* 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) + if (that->this.bit_depth != 16 && !pm->assume_16_bit_calculations) that->pm->limit += 4E-3; } } @@ -6781,11 +6810,16 @@ if (that->colour_type == PNG_COLOR_TYPE_PALETTE) image_pixel_convert_PLTE(that); /* Image now has RGB channels... */ +# if DIGITIZE { PNG_CONST png_modifier *pm = display->pm; - PNG_CONST unsigned int sample_depth = that->sample_depth; + const unsigned int sample_depth = that->sample_depth; + const unsigned int calc_depth = (pm->assume_16_bit_calculations ? 16 : + sample_depth); + const unsigned int gamma_depth = (sample_depth == 16 ? 16 : + (pm->assume_16_bit_calculations ? PNG_MAX_GAMMA_8 : sample_depth)); int isgray; double r, g, b; double rlo, rhi, glo, ghi, blo, bhi, graylo, grayhi; @@ -6799,48 +6833,48 @@ * 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*/); + rlo = digitize(rlo, calc_depth, 1/*round*/); rhi += that->rede; - rhi = digitize(pm, rhi, sample_depth, 1/*round*/); + rhi = digitize(rhi, calc_depth, 1/*round*/); g = glo = ghi = that->greenf; glo -= that->greene; - glo = digitize(pm, glo, sample_depth, 1/*round*/); + glo = digitize(glo, calc_depth, 1/*round*/); ghi += that->greene; - ghi = digitize(pm, ghi, sample_depth, 1/*round*/); + ghi = digitize(ghi, calc_depth, 1/*round*/); b = blo = bhi = that->bluef; blo -= that->bluee; - blo = digitize(pm, blo, sample_depth, 1/*round*/); + blo = digitize(blo, calc_depth, 1/*round*/); bhi += that->greene; - bhi = digitize(pm, bhi, sample_depth, 1/*round*/); + bhi = digitize(bhi, calc_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); + PNG_CONST double abse = calc_depth == 16 ? .5/65535 : .5/255; /* '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); + rlo = digitize(pow(rlo, power)-abse, calc_depth, 1); + rhi = digitize(pow(rhi, power)+abse, calc_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); + glo = digitize(pow(glo, power)-abse, calc_depth, 1); + ghi = digitize(pow(ghi, power)+abse, calc_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); + blo = digitize(pow(blo, power)-abse, calc_depth, 1); + bhi = digitize(pow(bhi, power)+abse, calc_depth, 1); } /* Now calculate the actual gray values. Although the error in the * coefficients depends on whether they were specified on the command @@ -6855,20 +6889,20 @@ 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 int do_round = data.gamma != 1 || calc_depth == 16; PNG_CONST double ce = 1. / 32768; - graylo = digitize(pm, rlo * (data.red_coefficient-ce) + + graylo = digitize(rlo * (data.red_coefficient-ce) + glo * (data.green_coefficient-ce) + - blo * (data.blue_coefficient-ce), sample_depth, do_round); + blo * (data.blue_coefficient-ce), gamma_depth, do_round); if (graylo <= 0) graylo = 0; - grayhi = digitize(pm, rhi * (data.red_coefficient+ce) + + grayhi = digitize(rhi * (data.red_coefficient+ce) + ghi * (data.green_coefficient+ce) + - bhi * (data.blue_coefficient+ce), sample_depth, do_round); + bhi * (data.blue_coefficient+ce), gamma_depth, do_round); if (grayhi >= 1) grayhi = 1; } @@ -6877,10 +6911,10 @@ { 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); + graylo = digitize(pow(graylo, power), sample_depth, 1); + grayhi = digitize(pow(grayhi, power), sample_depth, 1); } /* Now the error can be calculated. * @@ -6896,22 +6930,130 @@ if (fabs(gray - graylo) > err) err = fabs(graylo-gray); /* Check that this worked: */ - if (err > display->pm->limit) + if (err > 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, pm->limit, 6); + png_error(pp, buffer); + } + } + } +# else /* DIGITIZE */ + { + double r = that->redf; + double re = that->rede; + double g = that->greenf; + double ge = that->greene; + double b = that->bluef; + double be = that->bluee; + + /* The true gray case involves no math. */ + if (r == g && r == b) + { + gray = r; + err = re; + if (err < ge) err = ge; + if (err < be) err = be; + } + + else if (data.gamma == 1) + { + /* There is no need to do the conversions to and from linear space, + * so the calculation should be a lot more accurate. There is a + * built in 1/32768 error in the coefficients because they only have + * 15 bits and are adjusted to make sure they add up to 32768, so + * the result may have an additional error up to 1/32768. (Note + * that adding the 1/32768 here avoids needing to increase the + * global error limits to take this into account.) + */ + gray = r * data.red_coefficient + g * data.green_coefficient + + b * data.blue_coefficient; + err = re * data.red_coefficient + ge * data.green_coefficient + + be * data.blue_coefficient + 1./32768 + gray * 5 * DBL_EPSILON; + } + + else + { + /* The calculation happens in linear space, and this produces much + * wider errors in the encoded space. These are handled here by + * factoring the errors in to the calculation. There are two table + * lookups in the calculation and each introduces a quantization + * error defined by the table size. + */ + PNG_CONST png_modifier *pm = display->pm; + double in_qe = (that->sample_depth > 8 ? .5/65535 : .5/255); + double out_qe = (that->sample_depth > 8 ? .5/65535 : + (pm->assume_16_bit_calculations ? .5/(1< 1) rhi = 1; + r -= re + in_qe; if (r < 0) r = 0; + ghi = g + ge + in_qe; if (ghi > 1) ghi = 1; + g -= ge + in_qe; if (g < 0) g = 0; + bhi = b + be + in_qe; if (bhi > 1) bhi = 1; + b -= be + in_qe; if (b < 0) b = 0; + + r = pow(r, g1)*(1-DBL_EPSILON); rhi = pow(rhi, g1)*(1+DBL_EPSILON); + g = pow(g, g1)*(1-DBL_EPSILON); ghi = pow(ghi, g1)*(1+DBL_EPSILON); + b = pow(b, g1)*(1-DBL_EPSILON); bhi = pow(bhi, g1)*(1+DBL_EPSILON); + + /* Work out the lower and upper bounds for the gray value in the + * encoded space, then work out an average and error. Remove the + * previously added input quantization error at this point. + */ + gray = r * data.red_coefficient + g * data.green_coefficient + + b * data.blue_coefficient - 1./32768 - out_qe; + if (gray <= 0) + gray = 0; + else + { + gray *= (1 - 6 * DBL_EPSILON); + gray = pow(gray, data.gamma) * (1-DBL_EPSILON); + } + + grayhi = rhi * data.red_coefficient + ghi * data.green_coefficient + + bhi * data.blue_coefficient + 1./32768 + out_qe; + grayhi *= (1 + 6 * DBL_EPSILON); + if (grayhi >= 1) + grayhi = 1; + else + grayhi = pow(grayhi, data.gamma) * (1+DBL_EPSILON); + + err = (grayhi - gray) / 2; + gray = (grayhi + gray) / 2; + + if (err <= in_qe) + err = gray * DBL_EPSILON; + + else + err -= in_qe; + + /* Validate that the error is within limits (this has caused + * problems before, it's much easier to detect them here.) + */ + if (err > 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); + pos = safecatd(buffer, sizeof buffer, pos, pm->limit, 6); png_error(pp, buffer); } } } +# endif /* !DIGITIZE */ that->bluef = that->greenf = that->redf = gray; that->bluee = that->greene = that->rede = err; @@ -6958,9 +7100,9 @@ * 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.) + * This ignores the gamma (at present.) */ #define data ITDATA(background) static image_pixel data; @@ -6969,8 +7111,9 @@ 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 */ + int expand; 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 @@ -6986,12 +7129,16 @@ if (colour_type == 3) { colour_type = PNG_COLOR_TYPE_RGB; bit_depth = 8; + expand = 0; /* passing in an RGB not a pixel index */ } else + { bit_depth = that->this.bit_depth; + expand = 1; + } image_pixel_init(&data, random_bytes, colour_type, bit_depth, 0/*x*/, 0/*unused: palette*/); @@ -7010,13 +7157,11 @@ 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); + png_set_background(pp, &back, PNG_BACKGROUND_GAMMA_FILE, expand, 0); # else - png_set_background_fixed(pp, &back, PNG_BACKGROUND_GAMMA_FILE, - 1/*need expand*/, 0); + png_set_background_fixed(pp, &back, PNG_BACKGROUND_GAMMA_FILE, expand, 0); # endif this->next->set(this->next, that, pp, pi); } @@ -7346,9 +7491,9 @@ png_byte colour_type = 0; png_byte bit_depth = 0; unsigned int palette_number = 0; - while (next_format(&colour_type, &bit_depth, &palette_number)) + while (next_format(&colour_type, &bit_depth, &palette_number, 0)) { png_uint_32 counter = 0; size_t base_pos; char name[64]; @@ -8031,16 +8176,27 @@ /* 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) + if (pass == 0 && vi->use_input_precision && vi->dp->sbit) { /* 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. + * + * NOTE: at present because the libpng gamma table stuff has been + * changed to use a rounding algorithm to correct errors in 8-bit + * calculations the precise sbit calculation (a shift) has been + * lost. This can result in up to a +/-1 error in the presence of + * an sbit less than the bit depth. */ - double tmp = (isbit - .5)/sbit_max; +# if PNG_LIBPNG_VER < 10700 +# define SBIT_ERROR .5 +# else +# define SBIT_ERROR 1. +# endif + double tmp = (isbit - SBIT_ERROR)/sbit_max; if (tmp <= 0) tmp = 0; @@ -8057,12 +8213,12 @@ if (is_lo < 0) is_lo = 0; - tmp = (isbit + .5)/sbit_max; + tmp = (isbit + SBIT_ERROR)/sbit_max; - if (tmp <= 0) - tmp = 0; + if (tmp >= 1) + tmp = 1; else if (alpha >= 0 && vi->file_inverse > 0 && tmp < 1) tmp = pow(tmp, vi->file_inverse); @@ -8377,9 +8533,9 @@ * * Because there is limited precision in the input it is arguable that * an acceptable result is any valid result from input-.5 to input+.5. * The basic tests below do not do this, however if 'use_input_precision' - * is set a subsequent test is performed below. + * is set a subsequent test is performed above. */ PNG_CONST unsigned int samples_per_pixel = (out_ct & 2U) ? 3U : 1U; int processing; png_uint_32 y; @@ -8719,9 +8875,9 @@ /* 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)) + while (next_format(&colour_type, &bit_depth, &palette_number, 1/*gamma*/)) if (palette_number == 0) { double test_gamma = 1.0; while (test_gamma >= .4) @@ -8780,9 +8936,9 @@ png_byte colour_type = 0; png_byte bit_depth = 0; unsigned int palette_number = 0; - while (next_format(&colour_type, &bit_depth, &palette_number)) + while (next_format(&colour_type, &bit_depth, &palette_number, 1/*gamma*/)) { unsigned int i, j; for (i=0; ingamma_tests; ++i) for (j=0; jngamma_tests; ++j) @@ -8810,9 +8966,9 @@ { png_byte colour_type = 0, bit_depth = 0; unsigned int npalette = 0; - while (next_format(&colour_type, &bit_depth, &npalette)) + while (next_format(&colour_type, &bit_depth, &npalette, 1/*gamma*/)) if ((colour_type & PNG_COLOR_MASK_ALPHA) == 0 && ((colour_type == 3 && sbit < 8) || (colour_type != 3 && sbit < bit_depth))) { @@ -8845,8 +9001,9 @@ { # ifndef PNG_MAX_GAMMA_8 # define PNG_MAX_GAMMA_8 11 # endif +# define SBIT_16_TO_8 PNG_MAX_GAMMA_8 /* 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. * @@ -8862,30 +9019,30 @@ 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, + 1/pm->gammas[i], pm->gammas[j], SBIT_16_TO_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, + 1/pm->gammas[i], pm->gammas[j], SBIT_16_TO_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, + 1/pm->gammas[i], pm->gammas[j], SBIT_16_TO_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, + 1/pm->gammas[i], pm->gammas[j], SBIT_16_TO_8, pm->use_input_precision_16to8, 1 /*scale16*/); if (fail(pm)) return; @@ -9029,9 +9186,9 @@ /* Skip the non-alpha cases - there is no setting of a transparency colour at * present. */ - while (next_format(&colour_type, &bit_depth, &palette_number)) + while (next_format(&colour_type, &bit_depth, &palette_number, 1/*gamma*/)) if ((colour_type & PNG_COLOR_MASK_ALPHA) != 0) { unsigned int i, j; @@ -9051,33 +9208,48 @@ 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; + /* Use -1 to catch tests that were not actually run */ + pm->error_gray_2 = pm->error_gray_4 = pm->error_gray_8 = -1.; + pm->error_color_8 = -1.; + pm->error_indexed = -1.; + pm->error_gray_16 = pm->error_color_16 = -1.; +} + +static void +print_one(const char *leader, double err) +{ + if (err != -1.) + printf(" %s %.5f\n", leader, err); } static void -summarize_gamma_errors(png_modifier *pm, png_const_charp who, int low_bit_depth) +summarize_gamma_errors(png_modifier *pm, png_const_charp who, int low_bit_depth, + int indexed) { + fflush(stderr); + if (who) - printf("Gamma correction with %s:\n", who); + printf("\nGamma correction with %s:\n", who); + + else + printf("\nBasic gamma correction:\n"); 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); + print_one(" 2 bit gray: ", pm->error_gray_2); + print_one(" 4 bit gray: ", pm->error_gray_4); + print_one(" 8 bit gray: ", pm->error_gray_8); + print_one(" 8 bit color:", pm->error_color_8); + if (indexed) + print_one(" indexed: ", 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 + print_one("16 bit gray: ", pm->error_gray_16); + print_one("16 bit color:", pm->error_color_16); + + fflush(stdout); } static void perform_gamma_test(png_modifier *pm, int summary) @@ -9101,20 +9273,11 @@ /* 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) { + fflush(stderr); 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"); @@ -9124,12 +9287,27 @@ 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); + printf("increases when the image file includes an sBIT chunk.\n"); + fflush(stdout); } + + 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) + summarize_gamma_errors(pm, 0/*who*/, 1/*low bit depth*/, 1/*indexed*/); + + if (fail(pm)) + return; } /* The sbit tests produce much larger errors: */ if (pm->test_gamma_sbit) @@ -9137,9 +9315,12 @@ init_gamma_errors(pm); perform_gamma_sbit_tests(pm); if (summary) - summarize_gamma_errors(pm, "sBIT", pm->sbitlow < 8U); + summarize_gamma_errors(pm, "sBIT", pm->sbitlow < 8U, 1/*indexed*/); + + if (fail(pm)) + return; } #ifdef DO_16BIT /* Should be READ_16BIT_SUPPORTED */ if (pm->test_gamma_scale16) @@ -9149,12 +9330,17 @@ perform_gamma_scale16_tests(pm); if (summary) { - printf("Gamma correction with 16 to 8 bit reduction:\n"); + fflush(stderr); + printf("\nGamma 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); + fflush(stdout); } + + if (fail(pm)) + return; } #endif #ifdef PNG_READ_BACKGROUND_SUPPORTED @@ -9176,9 +9362,12 @@ pm->calculations_use_input_precision = 0; pm->maxout8 = maxout8; if (summary) - summarize_gamma_errors(pm, "background", 1); + summarize_gamma_errors(pm, "background", 1, 0/*indexed*/); + + if (fail(pm)) + return; } #endif #ifdef PNG_READ_ALPHA_MODE_SUPPORTED @@ -9201,9 +9390,12 @@ if (!calculations_use_input_precision) pm->calculations_use_input_precision = 0; if (summary) - summarize_gamma_errors(pm, "alpha mode", 1); + summarize_gamma_errors(pm, "alpha mode", 1, 0/*indexed*/); + + if (fail(pm)) + return; } #endif } #endif /* PNG_READ_GAMMA_SUPPORTED */ @@ -9709,8 +9901,21 @@ /* Default to error on warning: */ pm.this.treat_warnings_as_errors = 1; + /* Default assume_16_bit_calculations appropriately; this tells the checking + * code that 16-bit arithmetic is used for 8-bit samples when it would make a + * difference. + */ + pm.assume_16_bit_calculations = PNG_LIBPNG_VER >= 10700; + + /* Currently 16 bit expansion happens at the end of the pipeline, so the + * calculations are done in the input bit depth not the output. + * + * TODO: fix this + */ + pm.calculations_use_input_precision = 1U; + /* Store the test gammas */ pm.gammas = gammas; pm.ngammas = (sizeof gammas) / (sizeof gammas[0]); pm.ngamma_tests = 0; /* default to off */ @@ -9719,15 +9924,18 @@ 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. + * way libpng treates the 16_TO_8 flag when building the gamma tables in + * releases up to 1.6.0. * * TODO: review this */ pm.use_input_precision_16to8 = 1U; + pm.use_input_precision_sbit = 1U; /* because libpng now rounds sBIT */ /* 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 @@ -9736,13 +9944,14 @@ * 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.maxcalc8 = 1./255; /* +/-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 */ + pm.maxcalc16 =1./65535;/* +/-1 in 16 bits for compose errors */ + pm.maxcalcG = 1./((1< +#include + +#if (defined HAVE_CONFIG_H) && !(defined PNG_NO_CONFIG_H) +# include +#endif + +#ifdef HAVE_FEENABLEEXCEPT /* from config.h, if included */ +# include +#endif + +/* Define the following to use this test against your installed libpng, rather + * than the one being built here: + */ +#ifdef PNG_FREESTANDING_TESTS +# include +#else +# include "../../png.h" +#endif + +#ifdef PNG_WRITE_SUPPORTED /* else pngvalid can do nothing */ + +#if PNG_LIBPNG_VER < 10500 +/* This deliberately 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 + +#if PNG_LIBPNG_VER < 10600 + /* 1.6.0 constifies many APIs, the following exists to allow pngvalid to be + * compiled against earlier versions. + */ +# define png_const_structp png_structp +#endif + +#include /* 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 *****************************/ +#ifdef PNG_FREESTANDING_TESTS +# include +#else +# include "../visupng/cexcept.h" +#endif + +#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 +}; + +#ifdef PNG_READ_SUPPORTED +/* 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; +} +#endif /* PNG_READ_SUPPORTED */ + +/* 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" (Pseudo-Random Bit Sequences and Noise + * Generation.) + */ +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); +} + +#ifdef PNG_READ_SUPPORTED +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 */ +} + +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED +static int +random_choice(void) +{ + unsigned char x; + + RANDOMIZE(x); + + return x & 1; +} +#endif +#endif /* PNG_READ_SUPPORTED */ + +/* 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) (((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, unsigned 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 ? 1U : 16U) + +static int +next_format(png_bytep colour_type, png_bytep bit_depth, + unsigned int* palette_number, int no_low_depth_gray) +{ + if (*bit_depth == 0) + { + *colour_type = 0; + if (no_low_depth_gray) + *bit_depth = 8; + else + *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); +} + +#ifdef PNG_READ_SUPPORTED +/* 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; + } +} +#endif /* PNG_READ_SUPPORTED */ + +/*************************** 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); +} + +#ifdef PNG_READ_SUPPORTED +/* 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; + } +} +#endif /* PNG_READ_SUPPORTED */ + +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_const_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_const_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_const_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); +} + +#ifdef PNG_READ_SUPPORTED +/* 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; + } +} +#endif /* PNG_READ_SUPPORTED */ + +/* Functions to use as PNG callbacks. */ +static void +store_error(png_structp ppIn, png_const_charp message) /* PNG_NORETURN */ +{ + png_const_structp pp = ppIn; + 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 ppIn, png_const_charp message) +{ + png_const_structp pp = ppIn; + 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_const_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_const_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_const_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; + } + } +} +#endif /* PNG_READ_SUPPORTED */ + +static void +store_write(png_structp ppIn, png_bytep pb, png_size_t st) +{ + png_const_structp pp = ppIn; + 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 ppIn) +{ + UNUSED(ppIn) /*DOES NOTHING*/ +} + +#ifdef PNG_READ_SUPPORTED +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 ppIn, png_bytep pb, png_size_t st) +{ + png_const_structp pp = ppIn; + 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)); +} +#endif /* PNG_READ_SUPPORTED */ + +/* 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; +} + +#ifdef PNG_READ_SUPPORTED +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; +} +#endif /* PNG_READ_SUPPORTED */ + +/***************************** 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_const_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_const_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 ppIn, png_alloc_size_t cb) +{ + png_const_structp pp = ppIn; + 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 ppIn, png_voidp memory) +{ + png_const_structp pp = ppIn; + 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). + * This routine exists even when there is no read support to make the code + * tidier (avoid a mass of ifdefs) and so easier to maintain. + */ +static void +store_read_reset(png_store *ps) +{ +# ifdef PNG_READ_SUPPORTED + 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; + } +# endif + + /* 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; +} + +#ifdef PNG_READ_SUPPORTED +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; +} +#endif /* PNG_READ_SUPPORTED */ + +/* 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; + +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; + +#ifdef PNG_READ_SUPPORTED +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); +} + +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; +} + +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED +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; + } +} +#endif + +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; +} +#endif /* PNG_READ_SUPPORTED */ + +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 maxcalcG; /* 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 combination of transforms, */ + unsigned int test_transform :1; + + /* When to use the use_input_precision option, this controls the gamma + * validation code checks. If set any value that is within the transformed + * range input-.5 to input+.5 will be accepted, otherwise the value must be + * within the normal limits. It should not be necessary to set this; the + * result should always be exact within the permitted error limits. + */ + 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 the sample + * depth is 8 bits. + */ + 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->maxcalcG = 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->assume_16_bit_calculations = 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 + +/* This controls use of checks that explicitly know how libpng digitizes the + * samples in calculations; setting this circumvents simple error limit checking + * in the rgb_to_gray check, replacing it with an exact copy of the libpng 1.5 + * algorithm. + */ +#define DIGITIZE PNG_LIBPNG_VER < 10600 + +/* If pm->calculations_use_input_precision is set then operations will happen + * with the precision of the input, not the precision of the output depth. + * + * 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. + */ +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED +#if DIGITIZE +static double digitize(double value, int 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 = (1U << depth) -1; + + /* 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; +} +#endif +#endif /* RGB_TO_GRAY */ + +#ifdef PNG_READ_GAMMA_SUPPORTED +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 || + (pm->calculations_use_input_precision ? in_depth : out_depth) == 16) + 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->calculations_use_input_precision ? in_depth : out_depth) == 16) + return pm->maxcalc16; + else if (pm->assume_16_bit_calculations) + return pm->maxcalcG; + 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 || + (pm->calculations_use_input_precision ? in_depth : out_depth) == 16) + 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 ((pm->calculations_use_input_precision ? in_depth : out_depth) == 16) + 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 ((pm->calculations_use_input_precision ? in_depth : out_depth) == 16) + { + 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; +} +#endif /* PNG_READ_GAMMA_SUPPORTED */ + +/* 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); +} + +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED +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; +} +#endif + +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 ppIn, png_bytep pb, png_size_t st) +{ + png_const_structp pp = ppIn; + 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; +} + +#ifdef PNG_READ_GAMMA_SUPPORTED +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_GAMMA_SUPPORTED */ +#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] = (png_byte)((i&1) ? 255U : 0U); + values[i][2] = (png_byte)((i&2) ? 255U : 0U); + values[i][3] = (png_byte)((i&4) ? 255U : 0U); + } + + /* 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_const_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_const_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_const_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_const_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 */ + } +} + +#ifdef PNG_READ_SUPPORTED +/* The following can only be defined here, now we have the definitions + * of the transform image sizes. + */ +static png_uint_32 +standard_width(png_const_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_const_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_const_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; +} +#endif /* PNG_READ_SUPPORTED */ + +static void +transform_row(png_const_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] = (png_byte)(v & 0xff), v += 17, ++i; + return; + + case 2: + while (i<128/4) buffer[i] = (png_byte)(v & 0xff), v += 33, ++i; + return; + + case 4: + while (i<128/2) buffer[i] = (png_byte)(v & 0xff), v += 65, ++i; + return; + + case 8: + /* 256 bytes total, 128 bytes in each row set as follows: */ + while (i<128) buffer[i] = (png_byte)(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] = (png_byte)((v>>8) & 0xff); + buffer[2*i+1] = (png_byte)(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] = (png_byte)((v >> 8) & 0xff); + buffer[3*i+1] = (png_byte)(v & 0xff); + buffer[3*i+2] = (png_byte)(((v >> 8) ^ v) & 0xff); + ++v; + ++i; + } + + return; + + case 32: + /* 65535 pixels, r, g, b, a; just replicate */ + while (i<128) + { + buffer[4*i+0] = (png_byte)((v >> 8) & 0xff); + buffer[4*i+1] = (png_byte)(v & 0xff); + buffer[4*i+2] = (png_byte)((v >> 8) & 0xff); + buffer[4*i+3] = (png_byte)(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] = (png_byte)((t >> 8) & 0xff); + buffer[6*i+1] = (png_byte)(t & 0xff); + t *= 257; + buffer[6*i+2] = (png_byte)((t >> 8) & 0xff); + buffer[6*i+3] = (png_byte)(t & 0xff); + t *= 17; + buffer[6*i+4] = (png_byte)((t >> 8) & 0xff); + buffer[6*i+5] = (png_byte)(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] = (png_byte)((t >> 8) & 0xff); + buffer[8*i+1] = (png_byte)(t & 0xff); + buffer[8*i+4] = (png_byte)((t >> 8) & 0xff); + buffer[8*i+5] = (png_byte)(t & 0xff); + t *= 257; + buffer[8*i+2] = (png_byte)((t >> 8) & 0xff); + buffer[8*i+3] = (png_byte)(t & 0xff); + buffer[8*i+6] = (png_byte)((t >> 8) & 0xff); + buffer[8*i+7] = (png_byte)(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, unsigned 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 +# if (defined PNG_READ_zTXt_SUPPORTED) && (defined PNG_WRITE_zTXt_SUPPORTED) +# define TEXT_COMPRESSION PNG_TEXT_COMPRESSION_zTXt +# else +# define TEXT_COMPRESSION PNG_TEXT_COMPRESSION_NONE +# endif + { + 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 = TEXT_COMPRESSION; + 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, 0)) + { + 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); + +#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 = TEXT_COMPRESSION; + 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, 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); + } + } + } + +#ifdef PNG_TEXT_SUPPORTED + { + static char key[] = "end marker"; + static char comment[] = "end"; + png_text text; + + /* Use a compressed text string to test the correct interaction of text + * compression and IDAT compression. + */ + text.compression = TEXT_COMPRESSION; + text.key = key; + text.text = comment; + text.text_length = (sizeof comment)-1; + text.itxt_length = 0; + text.lang = 0; + text.lang_key = 0; + + png_set_text(pp, pi, &text, 1); + } +#endif + + 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); +} + +#ifdef PNG_READ_SUPPORTED +/* Return a row based on image id and 'y' for checking: */ +static void +standard_row(png_const_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); +} +#endif /* PNG_READ_SUPPORTED */ + +/* 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! + */ +/* TODO: the 'set' functions can probably all be made to take a + * png_const_structp rather than a modifiable one. + */ +#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; +# if PNG_LIBPNG_VER >= 10600 + char timestring[29]; +# endif + 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 */ + +# if PNG_LIBPNG_VER < 10600 + result = png_convert_to_rfc1123(pp, &pt); +# else + if (png_convert_to_rfc1123_buffer(timestring, &pt)) + result = timestring; + + else + result = NULL; +# endif + + 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 +} + +#ifdef PNG_READ_SUPPORTED +/* 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_const_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 (store_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_const_structp pp, + png_const_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 ppIn, png_bytep new_row, png_uint_32 y, int pass) +{ + png_const_structp pp = ppIn; + 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); +} + +#ifdef PNG_TEXT_SUPPORTED +static void +standard_check_text(png_const_structp pp, png_const_textp tp, + png_const_charp keyword, png_const_charp text) +{ + char msg[1024]; + size_t pos = safecat(msg, sizeof msg, 0, "text: "); + size_t ok; + + pos = safecat(msg, sizeof msg, pos, keyword); + pos = safecat(msg, sizeof msg, pos, ": "); + ok = pos; + + if (tp->compression != TEXT_COMPRESSION) + { + char buf[64]; + + sprintf(buf, "compression [%d->%d], ", TEXT_COMPRESSION, + tp->compression); + pos = safecat(msg, sizeof msg, pos, buf); + } + + if (tp->key == NULL || strcmp(tp->key, keyword) != 0) + { + pos = safecat(msg, sizeof msg, pos, "keyword \""); + if (tp->key != NULL) + { + pos = safecat(msg, sizeof msg, pos, tp->key); + pos = safecat(msg, sizeof msg, pos, "\", "); + } + + else + pos = safecat(msg, sizeof msg, pos, "null, "); + } + + if (tp->text == NULL) + pos = safecat(msg, sizeof msg, pos, "text lost, "); + + else + { + if (tp->text_length != strlen(text)) + { + char buf[64]; + sprintf(buf, "text length changed[%lu->%lu], ", + (unsigned long)strlen(text), (unsigned long)tp->text_length); + pos = safecat(msg, sizeof msg, pos, buf); + } + + if (strcmp(tp->text, text) != 0) + { + pos = safecat(msg, sizeof msg, pos, "text becomes \""); + pos = safecat(msg, sizeof msg, pos, tp->text); + pos = safecat(msg, sizeof msg, pos, "\" (was \""); + pos = safecat(msg, sizeof msg, pos, text); + pos = safecat(msg, sizeof msg, pos, "\"), "); + } + } + + if (tp->itxt_length != 0) + pos = safecat(msg, sizeof msg, pos, "iTXt length set, "); + + if (tp->lang != NULL) + { + pos = safecat(msg, sizeof msg, pos, "iTXt language \""); + pos = safecat(msg, sizeof msg, pos, tp->lang); + pos = safecat(msg, sizeof msg, pos, "\", "); + } + + if (tp->lang_key != NULL) + { + pos = safecat(msg, sizeof msg, pos, "iTXt keyword \""); + pos = safecat(msg, sizeof msg, pos, tp->lang_key); + pos = safecat(msg, sizeof msg, pos, "\", "); + } + + if (pos > ok) + { + msg[pos-2] = '\0'; /* Remove the ", " at the end */ + png_error(pp, msg); + } +} + +static void +standard_text_validate(standard_display *dp, png_const_structp pp, + png_const_infop pi) +{ + png_textp tp = NULL; + png_uint_32 num_text = png_get_text(pp, pi, &tp, NULL); + + if (num_text == 2 && tp != NULL) + { + standard_check_text(pp, tp, "image name", dp->ps->current->name); + standard_check_text(pp, tp+1, "end marker", "end"); + } + + else + { + char msg[64]; + + sprintf(msg, "expected two text items, got %lu", + (unsigned long)num_text); + png_error(pp, msg); + } +} +#else +# define standard_text_validate(dp,pp,pi) ((void)0) +#endif + +static void +standard_row_validate(standard_display *dp, png_const_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[%lu][%d] changed from %.2x to %.2x", + (unsigned long)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[%lu][%d] changed from %.2x to %.2x", + (unsigned long)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_const_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 ppIn, png_infop pi) +{ + png_const_structp pp = ppIn; + 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_text_validate(dp, pp, pi); + 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_text_validate(&d, pp, pi); + 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_const_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_const_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_const_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_const_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); + + /* use-input-precision 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. + */ + 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 calculations are at 8 bit precision, and the output actually + * consists of scaled 8-bit values, so 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 ppIn, png_infop pi) +{ + png_const_structp pp = ppIn; + 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); +} + +#ifdef PNG_READ_BACKGROUND_SUPPORTED +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; +} +#endif + +#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_const_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_const_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_const_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_const_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_const_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_const_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_const_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_const_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_const_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 computations have the form: + * + * r * rc + g * gc + b * bc + * + * Each component of which is +/-1/65535 from the gamma_to_1 table + * lookup, resulting in a base error of +/-6. The gamma_from_1 + * conversion adds another +/-2 in the 16-bit case and + * +/-(1<<(15-PNG_MAX_GAMMA_8)) in the 8-bit case. + */ + that->pm->limit += pow( +# if PNG_MAX_GAMMA_8 < 14 + (that->this.bit_depth == 16 ? 8. : + 6. + (1<<(15-PNG_MAX_GAMMA_8))) +# else + 8. +# endif + /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 && !pm->assume_16_bit_calculations) + 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_const_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... */ +# if DIGITIZE + { + PNG_CONST png_modifier *pm = display->pm; + const unsigned int sample_depth = that->sample_depth; + const unsigned int calc_depth = (pm->assume_16_bit_calculations ? 16 : + sample_depth); + const unsigned int gamma_depth = (sample_depth == 16 ? 16 : + (pm->assume_16_bit_calculations ? PNG_MAX_GAMMA_8 : 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(rlo, calc_depth, 1/*round*/); + rhi += that->rede; + rhi = digitize(rhi, calc_depth, 1/*round*/); + + g = glo = ghi = that->greenf; + glo -= that->greene; + glo = digitize(glo, calc_depth, 1/*round*/); + ghi += that->greene; + ghi = digitize(ghi, calc_depth, 1/*round*/); + + b = blo = bhi = that->bluef; + blo -= that->bluee; + blo = digitize(blo, calc_depth, 1/*round*/); + bhi += that->greene; + bhi = digitize(bhi, calc_depth, 1/*round*/); + + isgray = r==g && g==b; + + if (data.gamma != 1) + { + PNG_CONST double power = 1/data.gamma; + PNG_CONST double abse = calc_depth == 16 ? .5/65535 : .5/255; + + /* '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(pow(rlo, power)-abse, calc_depth, 1); + rhi = digitize(pow(rhi, power)+abse, calc_depth, 1); + + g = pow(g, power); + glo = digitize(pow(glo, power)-abse, calc_depth, 1); + ghi = digitize(pow(ghi, power)+abse, calc_depth, 1); + + b = pow(b, power); + blo = digitize(pow(blo, power)-abse, calc_depth, 1); + bhi = digitize(pow(bhi, power)+abse, calc_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 || calc_depth == 16; + PNG_CONST double ce = 1. / 32768; + + graylo = digitize(rlo * (data.red_coefficient-ce) + + glo * (data.green_coefficient-ce) + + blo * (data.blue_coefficient-ce), gamma_depth, do_round); + if (graylo <= 0) + graylo = 0; + + grayhi = digitize(rhi * (data.red_coefficient+ce) + + ghi * (data.green_coefficient+ce) + + bhi * (data.blue_coefficient+ce), gamma_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(pow(graylo, power), sample_depth, 1); + grayhi = digitize(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 > 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, pm->limit, 6); + png_error(pp, buffer); + } + } + } +# else /* DIGITIZE */ + { + double r = that->redf; + double re = that->rede; + double g = that->greenf; + double ge = that->greene; + double b = that->bluef; + double be = that->bluee; + + /* The true gray case involves no math. */ + if (r == g && r == b) + { + gray = r; + err = re; + if (err < ge) err = ge; + if (err < be) err = be; + } + + else if (data.gamma == 1) + { + /* There is no need to do the conversions to and from linear space, + * so the calculation should be a lot more accurate. There is a + * built in 1/32768 error in the coefficients because they only have + * 15 bits and are adjusted to make sure they add up to 32768, so + * the result may have an additional error up to 1/32768. (Note + * that adding the 1/32768 here avoids needing to increase the + * global error limits to take this into account.) + */ + gray = r * data.red_coefficient + g * data.green_coefficient + + b * data.blue_coefficient; + err = re * data.red_coefficient + ge * data.green_coefficient + + be * data.blue_coefficient + 1./32768 + gray * 5 * DBL_EPSILON; + } + + else + { + /* The calculation happens in linear space, and this produces much + * wider errors in the encoded space. These are handled here by + * factoring the errors in to the calculation. There are two table + * lookups in the calculation and each introduces a quantization + * error defined by the table size. + */ + PNG_CONST png_modifier *pm = display->pm; + double in_qe = (that->sample_depth > 8 ? .5/65535 : .5/255); + double out_qe = (that->sample_depth > 8 ? .5/65535 : + (pm->assume_16_bit_calculations ? .5/(1< 1) rhi = 1; + r -= re + in_qe; if (r < 0) r = 0; + ghi = g + ge + in_qe; if (ghi > 1) ghi = 1; + g -= ge + in_qe; if (g < 0) g = 0; + bhi = b + be + in_qe; if (bhi > 1) bhi = 1; + b -= be + in_qe; if (b < 0) b = 0; + + r = pow(r, g1)*(1-DBL_EPSILON); rhi = pow(rhi, g1)*(1+DBL_EPSILON); + g = pow(g, g1)*(1-DBL_EPSILON); ghi = pow(ghi, g1)*(1+DBL_EPSILON); + b = pow(b, g1)*(1-DBL_EPSILON); bhi = pow(bhi, g1)*(1+DBL_EPSILON); + + /* Work out the lower and upper bounds for the gray value in the + * encoded space, then work out an average and error. Remove the + * previously added input quantization error at this point. + */ + gray = r * data.red_coefficient + g * data.green_coefficient + + b * data.blue_coefficient - 1./32768 - out_qe; + if (gray <= 0) + gray = 0; + else + { + gray *= (1 - 6 * DBL_EPSILON); + gray = pow(gray, data.gamma) * (1-DBL_EPSILON); + } + + grayhi = rhi * data.red_coefficient + ghi * data.green_coefficient + + bhi * data.blue_coefficient + 1./32768 + out_qe; + grayhi *= (1 + 6 * DBL_EPSILON); + if (grayhi >= 1) + grayhi = 1; + else + grayhi = pow(grayhi, data.gamma) * (1+DBL_EPSILON); + + err = (grayhi - gray) / 2; + gray = (grayhi + gray) / 2; + + if (err <= in_qe) + err = gray * DBL_EPSILON; + + else + err -= in_qe; + + /* Validate that the error is within limits (this has caused + * problems before, it's much easier to detect them here.) + */ + if (err > 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, pm->limit, 6); + png_error(pp, buffer); + } + } + } +# endif /* !DIGITIZE */ + + 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) + * + * 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 */ + int expand; + 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; + expand = 0; /* passing in an RGB not a pixel index */ + } + + else + { + bit_depth = that->this.bit_depth; + expand = 1; + } + + 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, expand, 0); +# else + png_set_background_fixed(pp, &back, PNG_BACKGROUND_GAMMA_FILE, 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_const_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_const_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; + unsigned int palette_number = 0; + + while (next_format(&colour_type, &bit_depth, &palette_number, 0)) + { + 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_const_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_const_structp 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) + { +#ifdef PNG_READ_BACKGROUND_SUPPORTED + 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; +#endif + +#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.) + */ + UNUSED(alpha) + UNUSED(background) + UNUSED(compose) + 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 && vi->dp->sbit) + { + /* 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. + * + * NOTE: at present because the libpng gamma table stuff has been + * changed to use a rounding algorithm to correct errors in 8-bit + * calculations the precise sbit calculation (a shift) has been + * lost. This can result in up to a +/-1 error in the presence of + * an sbit less than the bit depth. + */ +# if PNG_LIBPNG_VER < 10600 +# define SBIT_ERROR .5 +# else +# define SBIT_ERROR 1. +# endif + double tmp = (isbit - SBIT_ERROR)/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 + SBIT_ERROR)/sbit_max; + + if (tmp >= 1) + tmp = 1; + + 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) + { +# ifdef PNG_READ_BACKGROUND_SUPPORTED + case PNG_BACKGROUND_GAMMA_SCREEN: + case PNG_BACKGROUND_GAMMA_FILE: + case PNG_BACKGROUND_GAMMA_UNIQUE: + use_background = (alpha >= 0 && alpha < 1); + /*FALL THROUGH*/ +# endif +# 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_const_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 %lu changed", + (unsigned long)y); + + png_error(pp, msg); + } + } /* row (y) loop */ + + dp->this.ps->validated = 1; +} + +static void +gamma_end(png_structp ppIn, png_infop pi) +{ + png_const_structp pp = ppIn; + 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; + unsigned 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, 1/*gamma*/)) + 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; + unsigned int palette_number = 0; + + while (next_format(&colour_type, &bit_depth, &palette_number, 1/*gamma*/)) + { + 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 +# define SBIT_16_TO_8 PNG_MAX_GAMMA_8 + /* 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], SBIT_16_TO_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], SBIT_16_TO_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], SBIT_16_TO_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], SBIT_16_TO_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; + unsigned 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, 1/*gamma*/)) + 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) +{ + /* Use -1 to catch tests that were not actually run */ + pm->error_gray_2 = pm->error_gray_4 = pm->error_gray_8 = -1.; + pm->error_color_8 = -1.; + pm->error_indexed = -1.; + pm->error_gray_16 = pm->error_color_16 = -1.; +} + +static void +print_one(const char *leader, double err) +{ + if (err != -1.) + printf(" %s %.5f\n", leader, err); +} + +static void +summarize_gamma_errors(png_modifier *pm, png_const_charp who, int low_bit_depth, + int indexed) +{ + fflush(stderr); + + if (who) + printf("\nGamma correction with %s:\n", who); + + else + printf("\nBasic gamma correction:\n"); + + if (low_bit_depth) + { + print_one(" 2 bit gray: ", pm->error_gray_2); + print_one(" 4 bit gray: ", pm->error_gray_4); + print_one(" 8 bit gray: ", pm->error_gray_8); + print_one(" 8 bit color:", pm->error_color_8); + if (indexed) + print_one(" indexed: ", pm->error_indexed); + } + + print_one("16 bit gray: ", pm->error_gray_16); + print_one("16 bit color:", pm->error_color_16); + + fflush(stdout); +} + +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; +# ifdef PNG_READ_BACKGROUND_SUPPORTED + double maxout8 = pm->maxout8; +# endif + + /* 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) + { + if (summary) + { + fflush(stderr); + 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"); + fflush(stdout); + } + + 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) + summarize_gamma_errors(pm, 0/*who*/, 1/*low bit depth*/, 1/*indexed*/); + + if (fail(pm)) + return; + } + + /* 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, 1/*indexed*/); + + if (fail(pm)) + return; + } + +#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) + { + fflush(stderr); + printf("\nGamma 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); + fflush(stdout); + } + + if (fail(pm)) + return; + } +#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, 0/*indexed*/); + + if (fail(pm)) + return; + } +#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, 0/*indexed*/); + + if (fail(pm)) + return; + } +#endif +} +#endif /* PNG_READ_GAMMA_SUPPORTED */ +#endif /* PNG_READ_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, 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]; + + anon_context(&pm.this); + + /* 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; + + /* Default assume_16_bit_calculations appropriately; this tells the checking + * code that 16-bit arithmetic is used for 8-bit samples when it would make a + * difference. + * + * TODO: IMPORTANT; set to '>= 10600' below to enable development, change + * this to the correct value before release! + */ + pm.assume_16_bit_calculations = PNG_LIBPNG_VER >= 10600; + + /* Currently 16 bit expansion happens at the end of the pipeline, so the + * calculations are done in the input bit depth not the output. + * + * TODO: fix this + */ + pm.calculations_use_input_precision = 1U; + + /* 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 in + * releases up to 1.6.0. + * + * TODO: review this + */ + pm.use_input_precision_16to8 = 1U; + pm.use_input_precision_sbit = 1U; /* because libpng now rounds sBIT */ + + /* 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 = 1./255; /* +/-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 =1./65535;/* +/-1 in 16 bits for compose errors */ + pm.maxcalcG = 1./((1<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 = 1U; + + else if (strcmp(*argv, "--use-calculation-precision") == 0) + pm.use_input_precision = 0; + + else if (strcmp(*argv, "--calculations-use-input-precision") == 0) + pm.calculations_use_input_precision = 1U; + + else if (strcmp(*argv, "--assume-16-bit-calculations") == 0) + pm.assume_16_bit_calculations = 1U; + + 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); +# ifdef PNG_READ_SUPPORTED + perform_standard_test(&pm); +# endif + perform_error_test(&pm); + } + + /* Various oddly sized images: */ + if (pm.test_size) + { + make_size_images(&pm.this); +# ifdef PNG_READ_SUPPORTED + perform_size_test(&pm); +# endif + } + +#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_anonymous + { + 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); + } + } + + else + { + fprintf(stderr, "%s: open failed\n", touch); + exit(1); + } + } + + return 0; +} +#else /* write not supported */ +int main(void) +{ + fprintf(stderr, "pngvalid: no write support in libpng, all tests skipped\n"); + return 0; +} +#endif diff -ru4NwbB libpng-1.6.0beta33/contrib/libtests/timepng.c libpng-1.7.0alpha02/contrib/libtests/timepng.c --- libpng-1.6.0beta33/contrib/libtests/timepng.c 2012-12-15 08:22:37.908164671 -0600 +++ libpng-1.7.0alpha02/contrib/libtests/timepng.c 2012-12-16 19:27:58.811190020 -0600 @@ -251,9 +251,9 @@ char filename[FILENAME_MAX+1]; while (fgets(filename, FILENAME_MAX+1, stdin)) { - int len = strlen(filename); + size_t len = strlen(filename); if (filename[len-1] == '\n') { filename[len-1] = 0; diff -ru4NwbB libpng-1.6.0beta33/contrib/pngminus/makefile.std libpng-1.7.0alpha02/contrib/pngminus/makefile.std --- libpng-1.6.0beta33/contrib/pngminus/makefile.std 2012-12-15 08:22:35.507669600 -0600 +++ libpng-1.7.0alpha02/contrib/pngminus/makefile.std 2012-12-16 19:27:56.256662335 -0600 @@ -7,11 +7,11 @@ RM=rm -f #PNGPATH = /usr/local -#PNGINC = -I$(PNGPATH)/include/libpng16 -#PNGLIB = -L$(PNGPATH)/lib -lpng16 -#PNGLIBS = $(PNGPATH)/lib/libpng16.a +#PNGINC = -I$(PNGPATH)/include/libpng17 +#PNGLIB = -L$(PNGPATH)/lib -lpng17 +#PNGLIBS = $(PNGPATH)/lib/libpng17.a PNGINC = -I../.. PNGLIB = -L../.. -lpng PNGLIBS = ../../libpng.a diff -ru4NwbB libpng-1.6.0beta33/contrib/tools/scale.c libpng-1.7.0alpha02/contrib/tools/scale.c --- libpng-1.6.0beta33/contrib/tools/scale.c 1969-12-31 18:00:00.000000000 -0600 +++ libpng-1.7.0alpha02/contrib/tools/scale.c 2012-12-16 19:27:58.900569879 -0600 @@ -0,0 +1,238 @@ +/* Given a target range and a source range work out an expression to scale from + * the source to the target of the form: + * + * (number * mult + add)>>16 + * + * The command arguments are: + * + * scale target source + * + * and the program works out a pair of numbers, mult and add, that evaluate: + * + * number * target + * round( --------------- ) + * source + * + * exactly for number in the range 0..source + */ +#define _ISOC99_SOURCE 1 + +#include +#include +#include +#include + +static double minerr; +static unsigned long minmult, minadd, minshift; +static long mindelta; + +static int +test(unsigned long target, unsigned long source, unsigned long mult, + long add, unsigned long shift, long delta) +{ + unsigned long i; + double maxerr = 0; + double rs = (double)target/source; + + for (i=0; i<=source; ++i) + { + unsigned long t = i*mult+add; + double err = fabs((t >> shift) - i*rs); + + if (err > minerr) + return 0; + + if (err > maxerr) + maxerr = err; + } + + if (maxerr < minerr) + { + minerr = maxerr; + minmult = mult; + minadd = add; + minshift = shift; + mindelta = delta; + } + + return maxerr < .5; +} + +static int +dotest(unsigned long target, unsigned long source, unsigned long mult, + long add, unsigned long shift, long delta, int print) +{ + if (test(target, source, mult, add, shift, delta)) + { + if (print & 4) + printf(" {%11lu,%6ld /* >>%lu */ }, /* %lu/%lu */\n", + mult, add, shift, target, source); + + else if (print & 2) + printf(" {%11lu,%6ld,%3lu }, /* %lu/%lu */\n", + mult, add, shift, target, source); + + else if (print) + printf("number * %lu/%lu = (number * %lu + %ld) >> %lu [delta %ld]\n", + target, source, mult, add, shift, delta); + + return 1; + } + + return 0; +} + +static int +find(unsigned long target, unsigned long source, int print, int fixshift) +{ + unsigned long shift = 0; + unsigned long shiftlim = 0; + + /* In the final math the sum is at most (source*mult+add) >> shift, so: + * + * source*mult+add < 1<<32 + * mult < (1<<32)/source + * + * but: + * + * mult = (target<>1)) / source; + long delta; + long limit = 1; /* seems to be sufficient */ + long add, start, end; + + end = 1<>%lu */ }, /* %lu/%lu ERROR: .5+%g*/\n", + minmult, minadd, minshift, target, source, minerr-.5); + + else if (print & 2) + printf(" {%11lu,%6ld,%3lu }, /* %lu/%lu ERROR: .5+%g*/\n", + minmult, minadd, minshift, target, source, minerr-.5); + + else if (print) + printf( + "number * %lu/%lu ~= (number * %lu + %ld) >> %lu +/-.5+%g [delta %ld]\n", + target, source, minmult, minadd, minshift, minerr-.5, mindelta); + + return 0; +} + +static void +usage(const char *prog) +{ + fprintf(stderr, + "usage: %s {--denominator|--maxshift|--code} target {source}\n" + " For each 'source' prints 'mult' and 'add' such that:\n\n" + " (number * mult + add) >> 16 = round(number*target/source)\n\n" + " for all integer values of number in the range 0..source.\n\n" + " --denominator: swap target and source (specify a single source first\n" + " and follow with multiple targets.)\n" + " --maxshift: find the lowest shift value that works for all the\n" + " repeated 'source' values\n" + " --code: output C code for array/structure initialization\n", + prog); + exit(1); +} + +int +main(int argc, const char **argv) +{ + int i, err = 0, maxshift = 0, firstsrc = 1, code = 0, denominator = 0; + unsigned long target, shift = 0; + + while (argc > 1) + { + if (strcmp(argv[firstsrc], "--maxshift") == 0) + { + maxshift = 1; + ++firstsrc; + } + + else if (strcmp(argv[firstsrc], "--code") == 0) + { + code = 1; + ++firstsrc; + } + + else if (strcmp(argv[firstsrc], "--denominator") == 0) + { + denominator = 1; + ++firstsrc; + } + + else + break; + } + + + if (argc < 2+firstsrc) + usage(argv[0]); + + target = strtoul(argv[firstsrc++], 0, 0); + if (target == 0) usage(argv[0]); + + for (i=firstsrc; i shift) shift = minshift; + } + + if (maxshift) for (i=firstsrc; i png_info_struct_size) - { - *ptr_ptr = NULL; - /* The following line is why this API should not be used: */ - free(info_ptr); - info_ptr = png_voidcast(png_inforp, png_malloc_base(NULL, - (sizeof *info_ptr))); - *ptr_ptr = info_ptr; - } - - /* Set everything to 0 */ - memset(info_ptr, 0, (sizeof *info_ptr)); -} - -/* The following API is not called internally */ -void PNGAPI -png_data_freer(png_const_structrp png_ptr, png_inforp info_ptr, - int freer, png_uint_32 mask) -{ - png_debug(1, "in png_data_freer"); - - if (png_ptr == NULL || info_ptr == NULL) - return; - - if (freer == PNG_DESTROY_WILL_FREE_DATA) - info_ptr->free_me |= mask; - - else if (freer == PNG_USER_WILL_FREE_DATA) - info_ptr->free_me &= ~mask; - - else - png_error(png_ptr, "Unknown freer parameter in png_data_freer"); -} - void PNGAPI png_free_data(png_const_structrp png_ptr, png_inforp info_ptr, png_uint_32 mask, int num) { @@ -472,11 +417,12 @@ #ifdef PNG_tRNS_SUPPORTED /* Free any tRNS entry */ if ((mask & PNG_FREE_TRNS) & info_ptr->free_me) { + info_ptr->valid &= ~PNG_INFO_tRNS; png_free(png_ptr, info_ptr->trans_alpha); info_ptr->trans_alpha = NULL; - info_ptr->valid &= ~PNG_INFO_tRNS; + info_ptr->num_trans = 0; } #endif #ifdef PNG_sCAL_SUPPORTED @@ -731,31 +677,8 @@ } return 1; } - -# if PNG_LIBPNG_VER < 10700 -/* To do: remove the following from libpng-1.7 */ -/* Original API that uses a private buffer in png_struct. - * Deprecated because it causes png_struct to carry a spurious temporary - * buffer (png_struct::time_buffer), better to have the caller pass this in. - */ -png_const_charp PNGAPI -png_convert_to_rfc1123(png_structrp png_ptr, png_const_timep ptime) -{ - if (png_ptr != NULL) - { - /* The only failure above if png_ptr != NULL is from an invalid ptime */ - if (!png_convert_to_rfc1123_buffer(png_ptr->time_buffer, ptime)) - png_warning(png_ptr, "Ignoring invalid time value"); - - else - return png_ptr->time_buffer; - } - - return NULL; -} -# endif # endif /* PNG_TIME_RFC1123_SUPPORTED */ #endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */ @@ -866,21 +789,8 @@ } #endif /* READ_UNKNOWN_CHUNKS */ #endif /* SET_UNKNOWN_CHUNKS */ -#ifdef PNG_READ_SUPPORTED -/* This function, added to libpng-1.0.6g, is untested. */ -int PNGAPI -png_reset_zstream(png_structrp png_ptr) -{ - if (png_ptr == NULL) - return Z_STREAM_ERROR; - - /* WARNING: this resets the window bits to the maximum! */ - return (inflateReset(&png_ptr->zstream)); -} -#endif /* PNG_READ_SUPPORTED */ - /* This function was added to libpng-1.0.7 */ png_uint_32 PNGAPI png_access_version_number(void) { @@ -2286,9 +2194,9 @@ void /* PRIVATE */ png_colorspace_set_rgb_coefficients(png_structrp png_ptr) { /* Set the rgb_to_gray coefficients from the colorspace. */ - if (!png_ptr->rgb_to_gray_coefficients_set && + if ((png_ptr->colorspace.flags & PNG_COLORSPACE_RGB_TO_GRAY_SET) == 0 && (png_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0) { /* png_set_background has not been called, get the coefficients from the Y * values of the colorspace colorants. @@ -3262,8 +3170,9 @@ #endif #ifdef PNG_READ_GAMMA_SUPPORTED /* A local convenience routine. */ +#ifndef PNG_FLOATING_ARITHMETIC_SUPPORTED static png_fixed_point png_product2(png_fixed_point a, png_fixed_point b) { /* The required result is 1/a * 1/b; the following preserves accuracy. */ @@ -3282,8 +3191,9 @@ #endif return 0; /* overflow */ } +#endif /* The inverse of the above. */ png_fixed_point png_reciprocal2(png_fixed_point a, png_fixed_point b) @@ -3660,8 +3570,9 @@ else return png_gamma_16bit_correct(value, gamma_val); } +#if 0 /* 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 * to shift the input values right (or 16-number_of_signifiant_bits). * @@ -3669,9 +3580,9 @@ * png_error (i.e. if one of the mallocs below fails) - i.e. the *table argument * should be somewhere that will be cleaned. */ static void -png_build_16bit_table(png_structrp png_ptr, png_uint_16pp *ptable, +png_build_16bit_table(png_structrp png_ptr, png_uint_16p *ptable, PNG_CONST unsigned int shift, PNG_CONST png_fixed_point gamma_val) { /* Various values derived from 'shift': */ PNG_CONST unsigned int num = 1U << (8U - shift); @@ -3750,9 +3661,9 @@ (png_uint_16pp)png_calloc(png_ptr, num * (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. + * 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 * (sizeof (png_uint_16))); @@ -3817,8 +3728,506 @@ else for (i=0; i<256; ++i) table[i] = (png_byte)i; } +#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \ + defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \ + defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) +static void +png_build_8to16_table(png_structrp png_ptr, png_uint_16pp ptable, + PNG_CONST png_fixed_point gamma_val) +{ + unsigned int i; + png_uint_16p table = *ptable = (png_uint_16p)png_malloc(png_ptr, + sizeof (png_uint_16[256])); + + if (png_gamma_significant(gamma_val)) for (i=0; i<256; i++) + table[i] = png_gamma_16bit_correct(i*257, gamma_val); + + else for (i=0; i<256; ++i) + table[i] = (png_uint_16)(i*257); +} + +static void +png_build_16to8_table(png_structrp png_ptr, png_bytepp ptable8, + png_uint_16pp ptable16, png_fixed_point gamma_val, int gamma_shift) + /* Build a table of (1<<(16-gamma_shift))+1 entries to find 8-bit values + * encoded by gamma_val. The table is to be indexed with a 16-bit value + * scaled down by gamma_shift: + * + * table[(value + (1<<(gamma_shift-1)) >> gamma_shift] + * + * Because of the rounding the table is 2^(16-gamma_shift)+1 entries. + * Each table entry must contain value^gamma_val, rounded to 8 bits. + */ +{ + unsigned int size = 1U << (16-gamma_shift); + unsigned int add = (gamma_shift > 0 ? 1U<<(gamma_shift-1) : 0U); + png_bytep table8; + png_uint_16p table16; + unsigned int i; + + /* If 'table8' it gets the output values as 8-bit bytes, if 'table16' is set + * the same values are scaled by 257 to give 16-bit values. + */ + if (ptable8) + { + table8 = png_voidcast(png_bytep, png_malloc(png_ptr, size+1)); + *ptable8 = table8; + table8[0] = 0; + } + + else + table8 = NULL; + + if (ptable16) + { + table16 = png_voidcast(png_uint_16p, png_malloc(png_ptr, + sizeof (png_uint_16) * (size+1))); + *ptable16 = table16; + table16[0] = 0; + } + + else + table16 = NULL; + + i = 1; + +# define FILL(val) do {\ + if (table8) table8[i] = (val);\ + if (table16) table16[i] = (png_uint_16)((val)*257U);\ + ++i; + } while (0) + + if (gamma_val < PNG_FP_1 - PNG_GAMMA_THRESHOLD_FIXED) + { + /* gamma < 1; the output values will jump by more than one for each table + * entry initially. + */ + png_byte last_out = 0; + + while (i < size) + { + png_byte out = (png_byte)PNG_DIV257(png_gamma_16bit_correct( + i << gamma_shift, gamma_val)); + + FILL(out); + + if (out <= last_out) + { + /* The table values are no longer advancing at each step, swap to + * finding the *last* table index corresponding to this value + * of 'out' - this is the one that corresponds to out+.5, below this + * is calculated as out*257+128; the exact value would be + * out*257+128.5, so we get a lower value, rounding ensures that we + * fill all the table entries corresponding to 'out' (with some very + * small chance of error at the boundaries.) + */ + png_fixed_point gamma_inv = png_reciprocal(gamma_val); + + while (out < 255 && i < size) + { + unsigned int next_index = (png_gamma_16bit_correct(out*257+128, + gamma_inv) + add) >> gamma_shift; + + while (i <= next_index && i < size) + FILL(out); + + ++out; + } + + break; /* fill remaining entries with 255 */ + } + } + } + + else if (gamma_val > PNG_FP_1 + PNG_GAMMA_THRESHOLD_FIXED) + { + /* gamma > 1; initially multiple table entries will correspond to the same + * value, invert the above loops. + */ + png_fixed_point gamma_inv = png_reciprocal(gamma_val); + png_byte out = 0; + + while (out < 255) + { + unsigned int next_index = (png_gamma_16bit_correct(out*257+128, + gamma_inv) + add) >> gamma_shift; + + /* If this 'out' value falls in the same slot as the last one + * recalculate the value for this slot. + */ + if (next_index <= i) + { + i = next_index; + break; + } + + while (i <= next_index && i < size) + FILL(out); + + ++out; + } + + while (i < size && out < 255) + { + out = (png_byte)PNG_DIV257(png_gamma_16bit_correct(i << gamma_shift, + gamma_val)); + FILL(out); + } + } + + else /* gamma_val not significant */ + { + png_byte out = 0; /* current output value */ + + add += 128; + + while (out < 255 && i < size) { + unsigned int next_index = (out*257+add) >> gamma_shift; + + while (i <= next_index && i < size) + FILL(out); + + ++out; + } + } + + /* Fill in the remainder of the table */ + while (i <= size) + FILL(255); +} +#endif /* BACKGROUND || ALPHA_MODE || RGB_TO_GRAY */ +#endif /* UNUSED */ + +#define PNG_GAMMA_TABLE_8 0 /* 8-bit entries in png_byte */ +#define PNG_GAMMA_TABLE_8_IN_16 1 /* 8-bit entries * 257 in png_uint_16 */ +#define PNG_GAMMA_TABLE_16 2 /* 16-bit entries in png_uint_16 */ + +typedef struct +{ + png_fixed_point gamma; + png_uint_32 mult; + unsigned int add; + unsigned int shift; /* input value is (i * mult + add) >> shift */ + unsigned int output; /* One of the above values */ + int adjust; /* Divide or multiple output by 257 */ + png_voidp table; /* Lookup table */ +} gamma_table_data; + +static unsigned int +write_gamma_table_entry(const gamma_table_data *data, png_uint_32 i) + /* Calculate and write a single entry into table[i], the value of the entry + * written is returned. + */ +{ + png_uint_32 in = (i * data->mult + data->add) >> data->shift; + unsigned int out; + + /* If the output is TABLE_8 with no adjust, or the output is not with an + * adjust, use 8-bit correction. + */ + if ((data->output == PNG_GAMMA_TABLE_8) != (data->adjust != 0)) + { + out = png_gamma_8bit_correct((unsigned int)in, data->gamma); + + if (data->adjust != 0) + out *= 257U; + } + + else /* 16-bit correction */ + { + out = png_gamma_16bit_correct((unsigned int)in, data->gamma); + + if (data->adjust != 0) + out = PNG_DIV257(out); + } + + if (data->output == PNG_GAMMA_TABLE_8) + ((png_bytep)data->table)[i] = (png_byte)out; + + else + ((png_uint_16p)data->table)[i] = (png_uint_16)out; + + return out; +} + +static void +write_gamma_table(const gamma_table_data *data, png_uint_32 lo, + unsigned int loval, png_uint_32 hi, unsigned int hival) + /* Fill in gamma table entries between lo and hi, exclusive. The entries at + * table[lo] and table[hi] have already been written, the intervening entries + * are written. + */ +{ + if (hi > lo+1) /* Else nothing to fill in */ + { + if (hival == loval) + { + /* All intervening entries must be the same. */ + if (data->output == PNG_GAMMA_TABLE_8) + { + png_bytep table8 = ((png_bytep)data->table); + + while (++lo < hi) + table8[lo] = (png_byte)loval; + } + + else + { + png_uint_16p table16 = ((png_uint_16p)data->table); + + while (++lo < hi) + table16[lo] = (png_uint_16)loval; + } + } + + else + { + png_uint_32 mid = (lo+hi) >> 1; + unsigned int midval = write_gamma_table_entry(data, mid); + + /* The algorithm used is to divide the entries to be written in half + * and fill in the middle. For all practical tables with significant + * gamma this will result in a performance gain because the expensive + * gamma correction arithmetic is avoided for some entries. + */ + write_gamma_table(data, lo, loval, mid, midval); + write_gamma_table(data, mid, midval, hi, hival); + } + } +} + +static void * +png_build_gamma_table(png_structrp png_ptr, png_fixed_point gamma_val, + unsigned int output/*as above*/, unsigned int input_depth, int use_shift) + /* Build a gamma lookup table to encode input_depth bit input values. + * The table will have 2^input_depth entries plus an extra one if use_shift + * is specified. With shift the table is accessed: + * + * table[(original-value + rounding) >> shift] + * + * And an extra entry exists to accomodate overflow of original-value on + * rounding. If use_shift is not specified the table is accessed with an + * input_depth bit value and the original values must have been correctly + * scaled to this range (not using a shift!) + * + * Each table entry contains input-value^gamma_val rounded to the output + * precision. This is 8 bit precision unless output is specified as + * PNG_GAMMA_TABLE_16, in which case it is 16-bit precision. For + * PNG_GAMMA_TABLE_8_IN_16 the 8-bit value is scaled to 16-bits by + * multiplying by 257. + */ +{ + png_uint_32 size; + unsigned int hival; + gamma_table_data data; + + /* If use_shift is true or if the input or output is not 8-bit the gamma + * correction will use the 16-bit correction code. This requires a value in + * the range 0..65535. For use_shift the value is simply: + * + * input << shift + * + * For the scaling case the value is: + * + * round(input * 65535 / ((1<> shift; + * + * With 'mult' and 'add' chosen to minimize the error for all input values + * in the range 0..((1< PNG_GAMMA_TABLE_8; + + if (use_shift) + { + /* The multiplier does the shift: */ + data.mult = 1U << (8-input_depth); + data.add = 0; + data.shift = 0; + if (input_depth < 8) ++size; + } + + else + { + data.mult = multadd255[input_depth-1].mult; + data.add = multadd255[input_depth-1].add; + data.shift = multadd255[input_depth-1].shift; + } + } + + else + { + /* 16-bit correction is used for cases where input or output require more + * than 8 bits. + */ + data.adjust = output == PNG_GAMMA_TABLE_8; + + if (use_shift) + { + data.mult = 1U << (16-input_depth); + data.add = 0; + data.shift = 0; + if (input_depth < 16) ++size; + } + + else + { + data.mult = multadd65535[input_depth-1].mult; + data.add = multadd65535[input_depth-1].add; + data.shift = multadd65535[input_depth-1].shift; + } + } + + if (output == PNG_GAMMA_TABLE_8) + { + data.table = png_malloc(png_ptr, size * sizeof (png_byte)); + ((png_bytep)data.table)[0] = 0; + hival = ((png_bytep)data.table)[size-1] = 255; + } + + else + { + /* Output is 16 bits, although it may only have 8 bits of precision */ + data.table = png_malloc(png_ptr, size * sizeof (png_uint_16)); + ((png_uint_16p)data.table)[0] = 0; + hival = ((png_uint_16p)data.table)[size-1] = 65535; + } + + if (png_gamma_significant(gamma_val)) + write_gamma_table(&data, 0, 0, size-1, hival); + + else /* gamma_val not significant */ + { + if (output == PNG_GAMMA_TABLE_8) + { + png_uint_32 i; + png_bytep table8 = ((png_bytep)data.table); + + if (data.adjust) + for (i=1; i> + data.shift); + + else + for (i=1; i> data.shift); + } + + else + { + png_uint_32 i; + png_uint_16p table16 = ((png_uint_16p)data.table); + + if (data.adjust) + for (i=1; i> + data.shift) * 257U); + + else + for (i=1; i> + data.shift); + } + } + + return data.table; +} + /* Used from png_read_destroy and below to release the memory used by the gamma * tables. */ void /* PRIVATE */ @@ -3826,19 +4235,10 @@ { png_free(png_ptr, png_ptr->gamma_table); png_ptr->gamma_table = NULL; - if (png_ptr->gamma_16_table != NULL) - { - int i; - int istop = (1 << (8 - png_ptr->gamma_shift)); - for (i = 0; i < istop; i++) - { - png_free(png_ptr, png_ptr->gamma_16_table[i]); - } png_free(png_ptr, png_ptr->gamma_16_table); png_ptr->gamma_16_table = NULL; - } #if defined(PNG_READ_BACKGROUND_SUPPORTED) || \ defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \ defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) @@ -3846,30 +4246,12 @@ png_ptr->gamma_from_1 = NULL; png_free(png_ptr, png_ptr->gamma_to_1); png_ptr->gamma_to_1 = NULL; - if (png_ptr->gamma_16_from_1 != NULL) - { - int i; - int istop = (1 << (8 - png_ptr->gamma_shift)); - for (i = 0; i < istop; i++) - { - png_free(png_ptr, png_ptr->gamma_16_from_1[i]); - } png_free(png_ptr, png_ptr->gamma_16_from_1); png_ptr->gamma_16_from_1 = NULL; - } - if (png_ptr->gamma_16_to_1 != NULL) - { - int i; - int istop = (1 << (8 - png_ptr->gamma_shift)); - for (i = 0; i < istop; i++) - { - png_free(png_ptr, png_ptr->gamma_16_to_1[i]); - } png_free(png_ptr, png_ptr->gamma_16_to_1); png_ptr->gamma_16_to_1 = NULL; - } #endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */ } /* We build the 8- or 16-bit gamma tables here. Note that for 16-bit @@ -3877,9 +4259,9 @@ * the future. Note also how the gamma_16 tables are segmented so that * we don't need to allocate > 64K chunks for a full 16-bit table. */ void /* PRIVATE */ -png_build_gamma_table(png_structrp png_ptr, int bit_depth) +png_build_gamma_tables(png_structrp png_ptr, int bit_depth) { png_debug(1, "in png_build_gamma_table"); /* Remove any existing table; this copes with multiple calls to @@ -3895,29 +4277,46 @@ } if (bit_depth <= 8) { - png_build_8bit_table(png_ptr, &png_ptr->gamma_table, - png_ptr->screen_gamma > 0 ? png_reciprocal2(png_ptr->colorspace.gamma, - png_ptr->screen_gamma) : PNG_FP_1); + png_ptr->gamma_table = png_voidcast(png_bytep, png_build_gamma_table( + png_ptr, png_ptr->screen_gamma > 0 ? + png_reciprocal2(png_ptr->colorspace.gamma, png_ptr->screen_gamma) : + PNG_FP_1, PNG_GAMMA_TABLE_8, 8/*input depth*/, 0/*scale*/)); #if defined(PNG_READ_BACKGROUND_SUPPORTED) || \ defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \ defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) if (png_ptr->transformations & (PNG_COMPOSE | PNG_RGB_TO_GRAY)) { - png_build_8bit_table(png_ptr, &png_ptr->gamma_to_1, - png_reciprocal(png_ptr->colorspace.gamma)); + /* This sets the accuracy of 8-bit composition and the 8-bit RGB to gray + * conversion - PNG_MAX_GAMMA_8 (the number of bits in the sixteen bit + * value that are considered significant.) + */ + png_ptr->gamma_to_1 = png_voidcast(png_uint_16p, png_build_gamma_table( + png_ptr, png_reciprocal(png_ptr->colorspace.gamma), + PNG_GAMMA_TABLE_16, 8/*input depth*/, 0/*scale*/)); + + png_ptr->gamma_from_1 = png_voidcast(png_bytep, png_build_gamma_table( + png_ptr, png_ptr->screen_gamma > 0 ? + png_reciprocal(png_ptr->screen_gamma) : + png_ptr->colorspace.gamma/* Probably doing rgb_to_gray */, + PNG_GAMMA_TABLE_8, PNG_MAX_GAMMA_8/*input depth*/, 1/*shift*/)); - png_build_8bit_table(png_ptr, &png_ptr->gamma_from_1, - png_ptr->screen_gamma > 0 ? png_reciprocal(png_ptr->screen_gamma) : - png_ptr->colorspace.gamma/* Probably doing rgb_to_gray */); + png_ptr->gamma_shift = 16-PNG_MAX_GAMMA_8; } #endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */ } else { png_byte shift, sig_bit; + int table_type; + +# ifdef PNG_16BIT_SUPPORTED + table_type = PNG_GAMMA_TABLE_16; +# else + table_type = PNG_GAMMA_TABLE_8_IN_16; +# endif if (png_ptr->color_type & PNG_COLOR_MASK_COLOR) { sig_bit = png_ptr->sig_bit.red; @@ -3930,26 +4329,8 @@ } else sig_bit = png_ptr->sig_bit.gray; - /* 16-bit gamma code uses this equation: - * - * ov = table[(iv & 0xff) >> gamma_shift][iv >> 8] - * - * 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 - * 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] - * - * So the table 'n' corresponds to all those 'iv' of: - * - * ..<(n+1 << gamma_shift)-1> - * - */ if (sig_bit > 0 && sig_bit < 16U) shift = (png_byte)(16U - sig_bit); /* shift == insignificant bits */ else @@ -3958,53 +4339,42 @@ if (png_ptr->transformations & (PNG_16_TO_8 | PNG_SCALE_16_TO_8)) { /* PNG_MAX_GAMMA_8 is the number of bits to keep - effectively * the significant bits in the *input* when the output will - * eventually be 8 bits. By default it is 11. + * eventually be 8 bits. */ if (shift < (16U - PNG_MAX_GAMMA_8)) shift = (16U - PNG_MAX_GAMMA_8); - } - if (shift > 8U) - shift = 8U; /* Guarantees at least one table! */ + table_type = PNG_GAMMA_TABLE_8_IN_16; + } png_ptr->gamma_shift = shift; -#ifdef PNG_16BIT_SUPPORTED - /* NOTE: prior to 1.5.4 this test used to include PNG_BACKGROUND (now - * PNG_COMPOSE). This effectively smashed the background calculation for - * 16-bit output because the 8-bit table assumes the result will be reduced - * to 8 bits. - */ - if (png_ptr->transformations & (PNG_16_TO_8 | PNG_SCALE_16_TO_8)) -#endif - png_build_16to8_table(png_ptr, &png_ptr->gamma_16_table, shift, - png_ptr->screen_gamma > 0 ? png_product2(png_ptr->colorspace.gamma, - png_ptr->screen_gamma) : PNG_FP_1); - -#ifdef PNG_16BIT_SUPPORTED - else - png_build_16bit_table(png_ptr, &png_ptr->gamma_16_table, shift, - png_ptr->screen_gamma > 0 ? png_reciprocal2(png_ptr->colorspace.gamma, - png_ptr->screen_gamma) : PNG_FP_1); -#endif + png_ptr->gamma_16_table = png_voidcast(png_uint_16p, png_build_gamma_table( + png_ptr, png_ptr->screen_gamma > 0 ? png_reciprocal2( + png_ptr->colorspace.gamma, png_ptr->screen_gamma) : PNG_FP_1, + table_type, (16-shift)/*input depth*/, 1/*shift*/)); #if defined(PNG_READ_BACKGROUND_SUPPORTED) || \ defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \ defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) if (png_ptr->transformations & (PNG_COMPOSE | PNG_RGB_TO_GRAY)) { - png_build_16bit_table(png_ptr, &png_ptr->gamma_16_to_1, shift, - png_reciprocal(png_ptr->colorspace.gamma)); + png_ptr->gamma_16_to_1 = png_voidcast(png_uint_16p, + png_build_gamma_table(png_ptr, + png_reciprocal(png_ptr->colorspace.gamma), PNG_GAMMA_TABLE_16, + (16-shift)/*input depth*/, 1/*shift*/)); /* Notice that the '16 from 1' table should be full precision, however * the lookup on this table still uses gamma_shift, so it can't be. * TODO: fix this. */ - png_build_16bit_table(png_ptr, &png_ptr->gamma_16_from_1, shift, - png_ptr->screen_gamma > 0 ? png_reciprocal(png_ptr->screen_gamma) : - png_ptr->colorspace.gamma/* Probably doing rgb_to_gray */); + png_ptr->gamma_16_from_1 = png_voidcast(png_uint_16p, + png_build_gamma_table(png_ptr, png_ptr->screen_gamma > 0 ? + png_reciprocal(png_ptr->screen_gamma) : + png_ptr->colorspace.gamma/* Probably doing rgb_to_gray */, + PNG_GAMMA_TABLE_16, (16-shift)/*input depth*/, 1/*shift*/)); } #endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */ } } diff -ru4NwbB libpng-1.6.0beta33/png.h libpng-1.7.0alpha02/png.h --- libpng-1.6.0beta33/png.h 2012-12-15 08:22:34.934444179 -0600 +++ libpng-1.7.0alpha02/png.h 2012-12-16 19:27:55.667529505 -0600 @@ -165,9 +165,10 @@ * 1.5.6 15 10506 15.so.15.6[.0] * 1.5.7beta01-05 15 10507 15.so.15.7[.0] * 1.5.7rc01-03 15 10507 15.so.15.7[.0] * 1.5.7 15 10507 15.so.15.7[.0] - * 1.6.0beta01-34 16 10600 16.so.16.0[.0] + * 1.6.0beta01-33 16 10600 16.so.16.0[.0] + * 1.7.0alpha01-02 17 10700 17.so.17.0[.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 @@ -1053,10 +1054,10 @@ PNG_EXPORTA(9, void, png_longjmp, (png_const_structrp png_ptr, int val), PNG_NORETURN); #ifdef PNG_READ_SUPPORTED -/* Reset the compression stream */ -PNG_EXPORTA(10, int, png_reset_zstream, (png_structrp png_ptr), PNG_DEPRECATED); +/* Reset the compression stream -- Removed from libpng-1.7.0 */ +PNG_REMOVED(10, int, png_reset_zstream, (png_structrp png_ptr), PNG_DEPRECATED) #endif /* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */ #ifdef PNG_USER_MEM_SUPPORTED @@ -1093,14 +1094,11 @@ /* Allocate and initialize the info structure */ PNG_EXPORTA(18, png_infop, png_create_info_struct, (png_const_structrp png_ptr), PNG_ALLOCATED); -/* DEPRECATED: this function allowed init structures to be created using the - * default allocation method (typically malloc). Use is deprecated in 1.6.0 and - * the API will be removed in the future. - */ -PNG_EXPORTA(19, void, png_info_init_3, (png_infopp info_ptr, - png_size_t png_info_struct_size), PNG_DEPRECATED); +/* Removed from libpng-1.7.0 */ +PNG_REMOVED(19, void, png_info_init_3, (png_infopp info_ptr, + png_size_t png_info_struct_size), PNG_DEPRECATED) /* Writes all the PNG information before the image. */ PNG_EXPORT(20, void, png_write_info_before_PLTE, (png_structrp png_ptr, png_const_inforp info_ptr)); @@ -1115,15 +1113,12 @@ #ifdef PNG_TIME_RFC1123_SUPPORTED /* Convert to a US string format: there is no localization support in this * routine. The original implementation used a 29 character buffer in - * png_struct, this will be removed in future versions. + * png_struct, this has been removed (in libpng 1.7.0). */ -#if PNG_LIBPNG_VER < 10700 -/* To do: remove this from libpng17 (and from libpng17/png.c and pngstruct.h) */ -PNG_EXPORTA(23, png_const_charp, png_convert_to_rfc1123, (png_structrp png_ptr, - png_const_timep ptime),PNG_DEPRECATED); -#endif +PNG_REMOVED(23, png_const_charp, png_convert_to_rfc1123, (png_structrp png_ptr, + png_const_timep ptime),PNG_DEPRECATED) PNG_EXPORT(241, int, png_convert_to_rfc1123_buffer, (char out[29], png_const_timep ptime)); #endif @@ -1618,32 +1613,38 @@ */ PNG_EXPORT(67, void, png_set_filter, (png_structrp png_ptr, int method, int filters)); -/* Flags for png_set_filter() to say which filters to use. The flags - * are chosen so that they don't conflict with real filter types - * below, in case they are supplied instead of the #defined constants. - * These values should NOT be changed. - */ -#define PNG_NO_FILTERS 0x00 -#define PNG_FILTER_NONE 0x08 -#define PNG_FILTER_SUB 0x10 -#define PNG_FILTER_UP 0x20 -#define PNG_FILTER_AVG 0x40 -#define PNG_FILTER_PAETH 0x80 -#define PNG_ALL_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP | \ - PNG_FILTER_AVG | PNG_FILTER_PAETH) - /* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now. - * These defines should NOT be changed. + * These defines match the values in the PNG specification. */ #define PNG_FILTER_VALUE_NONE 0 #define PNG_FILTER_VALUE_SUB 1 #define PNG_FILTER_VALUE_UP 2 #define PNG_FILTER_VALUE_AVG 3 #define PNG_FILTER_VALUE_PAETH 4 #define PNG_FILTER_VALUE_LAST 5 +/* The above values are valid arguments to png_set_filter() if only a single + * filter is to be used. If multiple filters are to be allowed (the default is + * to allow any of them) then a combination of the following masks must be used + * and the low three bits of the argument to png_set_filter must be 0. + * + * The resultant argument fits in a single byte. + */ +#define PNG_FILTER_NONE (0x08 << PNG_FILTER_VALUE_NONE) +#define PNG_FILTER_SUB (0x08 << PNG_FILTER_VALUE_SUB) +#define PNG_FILTER_UP (0x08 << PNG_FILTER_VALUE_UP) +#define PNG_FILTER_AVG (0x08 << PNG_FILTER_VALUE_AVG) +#define PNG_FILTER_PAETH (0x08 << PNG_FILTER_VALUE_PAETH) + +/* Then two convenience values. PNG_NO_FILTERS is the same as + * PNG_FILTER_VALUE_NONE, but this is harmless because they mean the same thing. + */ +#define PNG_NO_FILTERS 0x00 +#define PNG_ALL_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP | \ + PNG_FILTER_AVG | PNG_FILTER_PAETH) + #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* EXPERIMENTAL */ /* The "heuristic_method" is given by one of the PNG_FILTER_HEURISTIC_ * defines, either the default (minimum-sum-of-absolute-differences), or * the experimental method (weighted-minimum-sum-of-absolute-differences). @@ -1927,18 +1928,15 @@ * by libpng or by the application; this works on the png_info structure passed * in, it does not change the state for other png_info structures. * * It is unlikely that this function works correctly as of 1.6.0 and using it - * may result either in memory leaks or double free of allocated data. + * may result either in memory leaks or double free of allocated data. It was + * removed in libpng 1.7.0. */ -PNG_EXPORTA(99, void, png_data_freer, (png_const_structrp png_ptr, - png_inforp info_ptr, int freer, png_uint_32 mask), PNG_DEPRECATED); +PNG_REMOVED(99, void, png_data_freer, (png_const_structrp png_ptr, + png_inforp info_ptr, int freer, png_uint_32 mask), PNG_DEPRECATED) -/* Assignments for png_data_freer */ -#define PNG_DESTROY_WILL_FREE_DATA 1 -#define PNG_SET_WILL_FREE_DATA 1 -#define PNG_USER_WILL_FREE_DATA 2 -/* Flags for png_ptr->free_me and info_ptr->free_me */ +/* Flags for png_free_data */ #define PNG_FREE_HIST 0x0008 #define PNG_FREE_ICCP 0x0010 #define PNG_FREE_SPLT 0x0020 #define PNG_FREE_ROWS 0x0040 @@ -1954,12 +1952,16 @@ #define PNG_FREE_ALL 0x7fff #define PNG_FREE_MUL 0x4220 /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */ #ifdef PNG_USER_MEM_SUPPORTED -PNG_EXPORTA(100, png_voidp, png_malloc_default, (png_const_structrp png_ptr, - png_alloc_size_t size), PNG_ALLOCATED PNG_DEPRECATED); -PNG_EXPORTA(101, void, png_free_default, (png_const_structrp png_ptr, - png_voidp ptr), PNG_DEPRECATED); + /* These were deprecated in libpng 1.6.0 and have been removed from libpng + * 1.7.0; the functionality should be accessed by calling malloc or free + * directly or, if png_error handling is required, calling png_malloc. + */ +PNG_REMOVED(100, png_voidp, png_malloc_default, (png_const_structrp png_ptr, + png_alloc_size_t size), PNG_ALLOCATED PNG_DEPRECATED) +PNG_REMOVED(101, void, png_free_default, (png_const_structrp png_ptr, + png_voidp ptr), PNG_DEPRECATED) #endif #ifdef PNG_ERROR_TEXT_SUPPORTED /* Fatal error in PNG image of libpng - can't continue */ diff -ru4NwbB libpng-1.6.0beta33/pngconf.h libpng-1.7.0alpha02/pngconf.h --- libpng-1.6.0beta33/pngconf.h 2012-12-15 08:22:34.942006734 -0600 +++ libpng-1.7.0alpha02/pngconf.h 2012-12-16 19:27:55.675003466 -0600 @@ -1,8 +1,8 @@ /* pngconf.h - machine configurable file for libpng * - * libpng version 1.7.0alpha02 - December 17, 2012 + * libpng version 1.6.0beta32 - November 25, 2012 * * Copyright (c) 1998-2012 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-1.6.0beta33/pngerror.c libpng-1.7.0alpha02/pngerror.c --- libpng-1.6.0beta33/pngerror.c 2012-12-15 08:22:35.003725735 -0600 +++ libpng-1.7.0alpha02/pngerror.c 2012-12-16 19:27:55.738908459 -0600 @@ -1,8 +1,8 @@ /* pngerror.c - stub functions for i/o and memory allocation * - * Last changed in libpng 1.6.0 [(PENDING RELEASE)] + * Last changed in libpng 1.7.0 [(PENDING RELEASE)] * Copyright (c) 1998-2012 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.) * @@ -162,9 +162,9 @@ case PNG_NUMBER_FORMAT_02u: /* Expects at least 2 digits. */ mincount = 2; - /* FALL THROUGH */ + /* fall through */ case PNG_NUMBER_FORMAT_u: *--end = digits[number % 10]; number /= 10; @@ -172,9 +172,9 @@ case PNG_NUMBER_FORMAT_02x: /* This format expects at least two digits */ mincount = 2; - /* FALL THROUGH */ + /* fall through */ case PNG_NUMBER_FORMAT_x: *--end = digits[number & 0xf]; number >>= 4; diff -ru4NwbB libpng-1.6.0beta33/pngget.c libpng-1.7.0alpha02/pngget.c --- libpng-1.6.0beta33/pngget.c 2012-12-15 08:22:35.012327871 -0600 +++ libpng-1.7.0alpha02/pngget.c 2012-12-16 19:27:55.747596339 -0600 @@ -1,8 +1,8 @@ /* pngget.c - retrieval of values from info struct * - * Last changed in libpng 1.6.0 [(PENDING RELEASE)] + * Last changed in libpng 1.7.0 [(PENDING RELEASE)] * Copyright (c) 1998-2012 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-1.6.0beta33/pngmem.c libpng-1.7.0alpha02/pngmem.c --- libpng-1.6.0beta33/pngmem.c 2012-12-15 08:22:35.018121390 -0600 +++ libpng-1.7.0alpha02/pngmem.c 2012-12-16 19:27:55.753228471 -0600 @@ -109,33 +109,13 @@ ret = png_malloc_base(png_ptr, size); if (ret == NULL) - png_error(png_ptr, "Out of memory"); /* 'm' means png_malloc */ + png_error(png_ptr, "Out of memory"); return ret; } -#ifdef PNG_USER_MEM_SUPPORTED -PNG_FUNCTION(png_voidp,PNGAPI -png_malloc_default,(png_const_structrp png_ptr, png_alloc_size_t size), - PNG_ALLOCATED PNG_DEPRECATED) -{ - png_voidp ret; - - if (png_ptr == NULL) - return NULL; - - /* Passing 'NULL' here bypasses the application provided memory handler. */ - ret = png_malloc_base(NULL/*use malloc*/, size); - - if (ret == NULL) - png_error(png_ptr, "Out of Memory"); /* 'M' means png_malloc_default */ - - return ret; -} -#endif /* PNG_USER_MEM_SUPPORTED */ - /* This function was added at libpng version 1.2.3. The png_malloc_warn() * function will issue a png_warning and return NULL instead of issuing a * png_error, if it fails to allocate the requested memory. */ @@ -169,18 +149,9 @@ if (png_ptr->free_fn != NULL) png_ptr->free_fn(png_constcast(png_structrp,png_ptr), ptr); else - png_free_default(png_ptr, ptr); -} - -PNG_FUNCTION(void,PNGAPI -png_free_default,(png_const_structrp png_ptr, png_voidp ptr),PNG_DEPRECATED) -{ - if (png_ptr == NULL || ptr == NULL) - return; #endif /* PNG_USER_MEM_SUPPORTED */ - free(ptr); } #ifdef PNG_USER_MEM_SUPPORTED diff -ru4NwbB libpng-1.6.0beta33/pngpriv.h libpng-1.7.0alpha02/pngpriv.h --- libpng-1.6.0beta33/pngpriv.h 2012-12-15 08:22:34.952465247 -0600 +++ libpng-1.7.0alpha02/pngpriv.h 2012-12-16 19:27:55.685795123 -0600 @@ -5,9 +5,9 @@ * Copyright (c) 1998-2012 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 1.6.0 [(PENDING RELEASE)] + * Last changed in libpng 1.7.0 [(PENDING RELEASE)] * * This code is released under the libpng license. * For conditions of distribution and use, see the disclaimer * and license in png.h @@ -457,9 +457,9 @@ /* 0x80 (unused) */ #define PNG_HAVE_CHUNK_HEADER 0x100 #define PNG_WROTE_tIME 0x200 #define PNG_WROTE_INFO_BEFORE_PLTE 0x400 -#define PNG_BACKGROUND_IS_GRAY 0x800 + /* 0x800 (unused) */ #define PNG_HAVE_PNG_SIGNATURE 0x1000 #define PNG_HAVE_CHUNK_AFTER_IDAT 0x2000 /* Have another chunk after IDAT */ /* 0x4000 (unused) */ #define PNG_IS_READ_STRUCT 0x8000 /* Else is a write struct */ @@ -472,9 +472,9 @@ #define PNG_SWAP_BYTES 0x0010 #define PNG_INVERT_MONO 0x0020 #define PNG_QUANTIZE 0x0040 #define PNG_COMPOSE 0x0080 /* Was PNG_BACKGROUND */ -#define PNG_BACKGROUND_EXPAND 0x0100 + /* 0x0100 unused */ #define PNG_EXPAND_16 0x0200 /* Added to libpng 1.5.2 */ #define PNG_16_TO_8 0x0400 /* Becomes 'chop' in 1.5.4 */ #define PNG_RGBA 0x0800 #define PNG_EXPAND 0x1000 @@ -528,10 +528,10 @@ #define PNG_FLAG_STRIP_ERROR_TEXT 0x80000 #define PNG_FLAG_BENIGN_ERRORS_WARN 0x100000 /* Added to libpng-1.4.0 */ #define PNG_FLAG_APP_WARNINGS_WARN 0x200000 /* Added to libpng-1.6.0 */ #define PNG_FLAG_APP_ERRORS_WARN 0x400000 /* Added to libpng-1.6.0 */ - /* 0x800000 unused */ - /* 0x1000000 unused */ +#define PNG_FLAG_BACKGROUND_IS_GRAY 0x800000 +#define PNG_FLAG_BACKGROUND_EXPAND 0x1000000 /* 0x2000000 unused */ /* 0x4000000 unused */ /* 0x8000000 unused */ /* 0x10000000 unused */ @@ -732,8 +732,18 @@ png_compression_bufferp *list),PNG_EMPTY); /* Free the buffer list used by the compressed write code. */ #endif +#ifdef PNG_WRITE_FILTER_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_write_alloc_filter_row_buffers, + (png_structrp png_ptr, int filters),PNG_EMPTY); + /* Allocate pixel row buffers to cache filtered rows while testing candidate + * filters. + * TODO: avoid this, only one spare row buffer (at most) is required, this + * wastes a lot of memory for large images. + */ +#endif + #if defined(PNG_FLOATING_POINT_SUPPORTED) && \ !defined(PNG_FIXED_POINT_MACRO_SUPPORTED) && \ (defined(PNG_gAMA_SUPPORTED) || defined(PNG_cHRM_SUPPORTED) || \ defined(PNG_sCAL_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) || \ @@ -1801,9 +1811,9 @@ PNG_INTERNAL_FUNCTION(png_byte,png_gamma_8bit_correct,(unsigned int value, png_fixed_point gamma_value),PNG_EMPTY); PNG_INTERNAL_FUNCTION(void,png_destroy_gamma_table,(png_structrp png_ptr), PNG_EMPTY); -PNG_INTERNAL_FUNCTION(void,png_build_gamma_table,(png_structrp png_ptr, +PNG_INTERNAL_FUNCTION(void,png_build_gamma_tables,(png_structrp png_ptr, int bit_depth),PNG_EMPTY); #endif /* SIMPLIFIED READ/WRITE SUPPORT */ @@ -1862,9 +1872,10 @@ #endif /* SIMPLIFIED READ/WRITE */ #ifdef PNG_FILTER_OPTIMIZATIONS -PNG_INTERNAL_FUNCTION(void, PNG_FILTER_OPTIMIZATIONS, (png_structp png_ptr, unsigned int bpp), PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void, PNG_FILTER_OPTIMIZATIONS, (png_structrp png_ptr, + unsigned int bpp), PNG_EMPTY); /* This is the initialization function for hardware specific optimizations, * one implementation (for ARM NEON machines) is contained in * arm/filter_neon.c. It need not be defined - the generic code will be used * if not. diff -ru4NwbB libpng-1.6.0beta33/pngrio.c libpng-1.7.0alpha02/pngrio.c --- libpng-1.6.0beta33/pngrio.c 2012-12-15 08:22:35.048045941 -0600 +++ libpng-1.7.0alpha02/pngrio.c 2012-12-16 19:27:55.792251970 -0600 @@ -1,8 +1,8 @@ /* pngrio.c - functions for data input * - * Last changed in libpng 1.6.0 [(PENDING RELEASE)] + * Last changed in libpng 1.7.0 [(PENDING RELEASE)] * Copyright (c) 1998-2012 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.) * @@ -101,16 +101,18 @@ #else png_ptr->read_data_fn = read_data_fn; #endif +#ifdef PNG_WRITE_SUPPORTED /* It is an error to write to a read device */ if (png_ptr->write_data_fn != NULL) { png_ptr->write_data_fn = NULL; png_warning(png_ptr, "Can't set both read_data_fn and write_data_fn in the" " same structure"); } +#endif #ifdef PNG_WRITE_FLUSH_SUPPORTED png_ptr->output_flush_fn = NULL; #endif diff -ru4NwbB libpng-1.6.0beta33/pngrtran.c libpng-1.7.0alpha02/pngrtran.c --- libpng-1.6.0beta33/pngrtran.c 2012-12-15 08:22:35.066116908 -0600 +++ libpng-1.7.0alpha02/pngrtran.c 2012-12-16 19:27:55.810735169 -0600 @@ -1,8 +1,8 @@ /* pngrtran.c - transforms the data in a row for PNG readers * - * Last changed in libpng 1.6.0 [(PENDING RELEASE)] + * Last changed in libpng 1.7.0 [(PENDING RELEASE)] * Copyright (c) 1998-2012 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.) * @@ -129,11 +129,13 @@ if (!png_rtran_ok(png_ptr, 0) || background_color == NULL) return; - if (background_gamma_code == PNG_BACKGROUND_GAMMA_UNKNOWN) + if (background_gamma_code != PNG_BACKGROUND_GAMMA_SCREEN && + background_gamma_code != PNG_BACKGROUND_GAMMA_FILE && + background_gamma_code != PNG_BACKGROUND_GAMMA_UNIQUE) { - png_warning(png_ptr, "Application must supply a known background gamma"); + png_app_error(png_ptr, "invalid gamma type"); return; } png_ptr->transformations |= PNG_COMPOSE | PNG_STRIP_ALPHA; @@ -142,12 +144,14 @@ png_ptr->background = *background_color; png_ptr->background_gamma = background_gamma; png_ptr->background_gamma_type = (png_byte)(background_gamma_code); + if (need_expand) - png_ptr->transformations |= PNG_BACKGROUND_EXPAND; + png_ptr->flags |= PNG_FLAG_BACKGROUND_EXPAND; + else - png_ptr->transformations &= ~PNG_BACKGROUND_EXPAND; + png_ptr->flags &= ~PNG_FLAG_BACKGROUND_EXPAND; } # ifdef PNG_FLOATING_POINT_SUPPORTED void PNGAPI @@ -366,9 +370,9 @@ /* And obtain alpha pre-multiplication by composing on black: */ memset(&png_ptr->background, 0, (sizeof png_ptr->background)); png_ptr->background_gamma = png_ptr->colorspace.gamma; /* just in case */ png_ptr->background_gamma_type = PNG_BACKGROUND_GAMMA_FILE; - png_ptr->transformations &= ~PNG_BACKGROUND_EXPAND; + png_ptr->flags &= ~PNG_FLAG_BACKGROUND_EXPAND; if (png_ptr->transformations & PNG_COMPOSE) png_error(png_ptr, "conflicting calls to set alpha mode and background"); @@ -1004,9 +1008,11 @@ green_int = (png_uint_16)(((png_uint_32)green*32768)/100000); png_ptr->rgb_to_gray_red_coeff = red_int; png_ptr->rgb_to_gray_green_coeff = green_int; - png_ptr->rgb_to_gray_coefficients_set = 1; +# if defined PNG_COLORS_SPACE_SUPPORTED || defined PNG_GAMMA_SUPPORTED + png_ptr->colorspace.flags |= PNG_COLORSPACE_RGB_TO_GRAY_SET; +# endif } else { @@ -1090,25 +1096,265 @@ /* Initialize everything needed for the read. This includes modifying * the palette. */ +#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\ + defined(PNG_READ_ALPHA_MODE_SUPPORTED) +static void +gamma_correct_background(unsigned int value, unsigned int depth, + png_uint_16p backgroundp, png_uint_16p background_1p, + png_fixed_point gamma_correct, png_fixed_point gamma_to_1) +{ + switch (depth) + { + case 8: + if (gamma_correct != PNG_FP_1) + *backgroundp = png_gamma_8bit_correct(value, gamma_correct); + + else + *backgroundp = (png_uint_16)value; + + if (gamma_to_1 != PNG_FP_1) + *background_1p = png_gamma_16bit_correct(value*257, gamma_to_1); + + else + *background_1p = (png_uint_16)(value*257); + + return; + + case 16: + if (gamma_correct != PNG_FP_1) + *backgroundp = png_gamma_16bit_correct(value, gamma_correct); + + else + *backgroundp = (png_uint_16)value; + + if (gamma_to_1 != PNG_FP_1) + *background_1p = png_gamma_16bit_correct(value, gamma_to_1); + + else + *background_1p = (png_uint_16)value; + + return; + + default: + /* Low bit depth gray levels; do no harm. */ + break; + } + + *backgroundp = (png_uint_16)value; + *background_1p = 0; /* should not be used */ +} -/*For the moment 'png_init_palette_transformations' and - * 'png_init_rgb_transformations' only do some flag canceling optimizations. - * The intent is that these two routines should have palette or rgb operations - * extracted from 'png_init_read_transformations'. - */ static void /* PRIVATE */ -png_init_palette_transformations(png_structrp png_ptr) +png_init_background_transformations(png_structrp png_ptr) + /* Set the png_ptr->background and png_ptr->background_1 members correctly + * for the bit depth and format. + */ { - /* Called to handle the (input) palette case. In png_do_read_transformations - * the first step is to expand the palette if requested, so this code must - * take care to only make changes that are invariant with respect to the - * palette expansion, or only do them if there is no expansion. + /* png_ptr->background is only assigned by png_set_background and + * png_set_alpha_mode (which just zeros out the fields.) png_set_background + * can set the PNG_FLAG_BACKGROUND_EXPAND flag if the input value is in the + * file format, for example if it comes from a bKGD chunk. + * + * Under some circumstances deficiencies in the current libpng code mean that + * the bit depth of the values must differ from the final bit depth; the bit + * depth has to match that at which the processing of the image pixels + * happens and this is not always the final bit depth. This is fixed up + * here. * - * STRIP_ALPHA has already been handled in the caller (by setting num_trans - * to 0.) + * First find the required depth. */ + unsigned int bit_depth, required_bit_depth; + unsigned int color_type = png_ptr->color_type; + const png_uint_32 transform = png_ptr->transformations; + const int expand = (png_ptr->flags & PNG_FLAG_BACKGROUND_EXPAND) != 0; + + if (color_type & PNG_COLOR_MASK_PALETTE) + required_bit_depth = bit_depth = 8; + + else + { + required_bit_depth = bit_depth = png_ptr->bit_depth; + + /* But not PNG_EXPAND_16 at present because it happens after the compose + * operation where the background is used! + */ + if (bit_depth < 8 && (transform & PNG_EXPAND) != 0) + required_bit_depth = 8; + } + + /* bit_depth and color_type now refer to the original file data and + * required_bit_depth is correct for the processing libpng does, however it + * does not necessarily match the output the application gets, fix that and + * the color type here: + */ + if (!expand) + { + /* The background bit_depth and color_type need correcting */ + if ((transform & PNG_EXPAND) != 0) + color_type &= ~PNG_COLOR_MASK_PALETTE; + + /* The RGB<->gray transformations do the to gray operation first, then the + * from gray. + */ + if ((transform & PNG_RGB_TO_GRAY) != 0) + color_type &= ~PNG_COLOR_MASK_COLOR; + + if ((transform & PNG_GRAY_TO_RGB) != 0) + color_type |= PNG_COLOR_MASK_COLOR; + + bit_depth = required_bit_depth; + + /* The expansion to 16 bits and the scaling back from 16 bits per + * component to only 8 happens after the background processing (at + * present) so these transforms only affect the screen value, not the + * required value. Note that the 16_TO_8 conversions happen before the 8 + * to 16 one, so in theory both could occur - the order of the tests below + * must be correct! + * + * TODO: Note that the second of these changes cause an input 16-bit + * background value to be temporarily crushed to 8-bits per component, + * losing precision. This is a bug and should be fixed. + */ + if (bit_depth == 16 && + (transform & (PNG_16_TO_8|PNG_SCALE_16_TO_8)) != 0) + bit_depth = 8; + + if (bit_depth == 8 && (color_type & PNG_COLOR_MASK_PALETTE) == 0 && + (transform & PNG_EXPAND_16) != 0) + bit_depth = 16; + } + + /* Now make the background have the correct format. This involves reading the + * correct fields from png_ptr->background, adjusting the bit depth of the + * result and potentially gamma correcting the value then calculating the + * png_ptr->background_1 values too. + */ + { + unsigned int mult = 1; + png_fixed_point gamma_to_1, gamma_correct; + + switch (png_ptr->background_gamma_type) + { + case PNG_BACKGROUND_GAMMA_SCREEN: + gamma_to_1 = png_ptr->screen_gamma; + gamma_correct = PNG_FP_1; + break; + + case PNG_BACKGROUND_GAMMA_FILE: + gamma_to_1 = png_reciprocal(png_ptr->colorspace.gamma); + gamma_correct = png_reciprocal2(png_ptr->colorspace.gamma, + png_ptr->screen_gamma); + break; + + case PNG_BACKGROUND_GAMMA_UNIQUE: + gamma_to_1 = png_reciprocal(png_ptr->background_gamma); + gamma_correct = png_reciprocal2(png_ptr->background_gamma, + png_ptr->screen_gamma); + break; + + default: + gamma_to_1 = PNG_FP_1; + gamma_correct = PNG_FP_1; + break; + } + +# define CORRECT(v, c)\ + gamma_correct_background((v)*mult, bit_depth,\ + &png_ptr->background.c, &png_ptr->background_1.c,\ + gamma_correct, gamma_to_1);\ + if (bit_depth > required_bit_depth)\ + png_ptr->background.c =\ + (png_uint_16)PNG_DIV257(png_ptr->background.c) + + /* The multiplier 'mult' scales the values to 'required_depth', + * 'bit_depth' is the depth of the resultant values. + */ + while (bit_depth < required_bit_depth) + mult += mult << bit_depth, bit_depth <<= 1; + + /* In the event that this still leaves the background bit depth greater + * than the libpng required depth scale the values back to the 8-bit + * range, the test below verifies that this is correct. + */ + if (bit_depth > required_bit_depth) + { + if (bit_depth != 16 || required_bit_depth != 8) + png_error(png_ptr, "internal error handling background depth"); + } + + if ((color_type & PNG_COLOR_MASK_COLOR) != 0) + { + png_ptr->flags &= ~PNG_FLAG_BACKGROUND_IS_GRAY; /* checked below */ + + /* If need_expand was passed to png_set_background the background value + * was in the file format, therefore if the file is a palette file the + * background will have been an index into the palette. Notice that if + * need_expand was false then the color is RGB even if the output still + * has a palette. + */ + if (expand && (color_type & PNG_COLOR_MASK_PALETTE) != 0) + { + unsigned int index = png_ptr->background.index; + + if (index < png_ptr->num_palette && png_ptr->palette != NULL) + { + /* In fact 'mult' is always 1 at present in this case */ + CORRECT(png_ptr->palette[index].red, red); + CORRECT(png_ptr->palette[index].green, green); + CORRECT(png_ptr->palette[index].blue, blue); + } + + else + { + png_app_error(png_ptr, "out of range background index"); + memset(&png_ptr->background, 0, sizeof png_ptr->background); + memset(&png_ptr->background_1, 0, sizeof png_ptr->background_1); + } + } + + else + { + CORRECT(png_ptr->background.red, red); + CORRECT(png_ptr->background.green, green); + CORRECT(png_ptr->background.blue, blue); + } + + if (png_ptr->background.red == png_ptr->background.blue && + png_ptr->background.red == png_ptr->background.green) + { + png_ptr->flags |= PNG_FLAG_BACKGROUND_IS_GRAY; + png_ptr->background.gray = png_ptr->background.red; + png_ptr->background_1.gray = png_ptr->background_1.red; + } + + else + png_ptr->background.gray = png_ptr->background_1.gray = 0; + } + + else + { + png_ptr->flags |= PNG_FLAG_BACKGROUND_IS_GRAY; + + CORRECT(png_ptr->background.gray, gray); + + png_ptr->background.red = + png_ptr->background.green = + png_ptr->background.blue = png_ptr->background.gray; + + png_ptr->background_1.red = + png_ptr->background_1.green = + png_ptr->background_1.blue = png_ptr->background_1.gray; + } +# undef CORRECT + } +} +#endif /* READ_BACKGROUND || READ_ALPHA_MODE */ + +static void /* PRIVATE */ +png_init_palette_transformations(png_structrp png_ptr) +{ int input_has_alpha = 0; int input_has_transparency = 0; if (png_ptr->num_trans > 0) @@ -1128,57 +1374,17 @@ /* If no alpha we can optimize. */ if (!input_has_alpha) { /* Any alpha means background and associative alpha processing is - * required, however if the alpha is 0 or 1 throughout OPTIIMIZE_ALPHA + * required, however if the alpha is 0 or 1 throughout OPTIMIZE_ALPHA * and ENCODE_ALPHA are irrelevant. */ png_ptr->transformations &= ~PNG_ENCODE_ALPHA; png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; if (!input_has_transparency) - png_ptr->transformations &= ~(PNG_COMPOSE | PNG_BACKGROUND_EXPAND); - } - -#if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED) - /* png_set_background handling - deals with the complexity of whether the - * background color is in the file format or the screen format in the case - * where an 'expand' will happen. - */ - - /* The following code cannot be entered in the alpha pre-multiplication case - * because PNG_BACKGROUND_EXPAND is cancelled below. - */ - if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) && - (png_ptr->transformations & PNG_EXPAND)) - { - { - png_ptr->background.red = - png_ptr->palette[png_ptr->background.index].red; - png_ptr->background.green = - png_ptr->palette[png_ptr->background.index].green; - png_ptr->background.blue = - png_ptr->palette[png_ptr->background.index].blue; - -#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED - if (png_ptr->transformations & PNG_INVERT_ALPHA) - { - if (!(png_ptr->transformations & PNG_EXPAND_tRNS)) - { - /* Invert the alpha channel (in tRNS) unless the pixels are - * going to be expanded, in which case leave it for later - */ - int i, istop = png_ptr->num_trans; - - for (i=0; itrans_alpha[i] = (png_byte)(255 - - png_ptr->trans_alpha[i]); - } - } -#endif /* PNG_READ_INVERT_ALPHA_SUPPORTED */ + png_ptr->transformations &= ~PNG_COMPOSE; } - } /* background expand and (therefore) no alpha association. */ -#endif /* PNG_READ_EXPAND_SUPPORTED && PNG_READ_BACKGROUND_SUPPORTED */ } static void /* PRIVATE */ png_init_rgb_transformations(png_structrp png_ptr) @@ -1202,68 +1408,10 @@ png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; # endif if (!input_has_transparency) - png_ptr->transformations &= ~(PNG_COMPOSE | PNG_BACKGROUND_EXPAND); - } - -#if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED) - /* png_set_background handling - deals with the complexity of whether the - * background color is in the file format or the screen format in the case - * where an 'expand' will happen. - */ - - /* The following code cannot be entered in the alpha pre-multiplication case - * because PNG_BACKGROUND_EXPAND is cancelled below. - */ - if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) && - (png_ptr->transformations & PNG_EXPAND) && - !(png_ptr->color_type & PNG_COLOR_MASK_COLOR)) - /* i.e., GRAY or GRAY_ALPHA */ - { - { - /* Expand background and tRNS chunks */ - int gray = png_ptr->background.gray; - int trans_gray = png_ptr->trans_color.gray; - - switch (png_ptr->bit_depth) - { - case 1: - gray *= 0xff; - trans_gray *= 0xff; - break; - - case 2: - gray *= 0x55; - trans_gray *= 0x55; - break; - - case 4: - gray *= 0x11; - trans_gray *= 0x11; - break; - - default: - - case 8: - /* FALL THROUGH (Already 8 bits) */ - - case 16: - /* Already a full 16 bits */ - break; - } - - png_ptr->background.red = png_ptr->background.green = - png_ptr->background.blue = (png_uint_16)gray; - - if (!(png_ptr->transformations & PNG_EXPAND_tRNS)) - { - png_ptr->trans_color.red = png_ptr->trans_color.green = - png_ptr->trans_color.blue = (png_uint_16)trans_gray; - } + png_ptr->transformations &= ~PNG_COMPOSE; } - } /* background expand and (therefore) no alpha association. */ -#endif /* PNG_READ_EXPAND_SUPPORTED && PNG_READ_BACKGROUND_SUPPORTED */ } void /* PRIVATE */ png_init_read_transformations(png_structrp png_ptr) @@ -1346,18 +1494,18 @@ * * 1) PNG_EXPAND (including PNG_EXPAND_tRNS) * 2) PNG_STRIP_ALPHA (if no compose) * 3) PNG_RGB_TO_GRAY - * 4) PNG_GRAY_TO_RGB iff !PNG_BACKGROUND_IS_GRAY + * 4) PNG_GRAY_TO_RGB iff !PNG_FLAG_BACKGROUND_IS_GRAY * 5) PNG_COMPOSE * 6) PNG_GAMMA * 7) PNG_STRIP_ALPHA (if compose) * 8) PNG_ENCODE_ALPHA * 9) PNG_SCALE_16_TO_8 * 10) PNG_16_TO_8 * 11) PNG_QUANTIZE (converts to palette) * 12) PNG_EXPAND_16 - * 13) PNG_GRAY_TO_RGB iff PNG_BACKGROUND_IS_GRAY + * 13) PNG_GRAY_TO_RGB iff PNG_FLAG_BACKGROUND_IS_GRAY * 14) PNG_INVERT_MONO * 15) PNG_SHIFT * 16) PNG_PACK * 17) PNG_BGR @@ -1368,18 +1516,21 @@ * 22) PNG_SWAP_BYTES * 23) PNG_USER_TRANSFORM [must be last] */ #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED - if ((png_ptr->transformations & PNG_STRIP_ALPHA) && - !(png_ptr->transformations & PNG_COMPOSE)) + if (png_ptr->transformations & PNG_STRIP_ALPHA) + { + if (!(png_ptr->transformations & PNG_FILLER)) + png_ptr->transformations &= ~(PNG_INVERT_ALPHA|PNG_SWAP_ALPHA); + + if (!(png_ptr->transformations & PNG_COMPOSE)) { /* Stripping the alpha channel happens immediately after the 'expand' - * transformations, before all other transformation, so it cancels out + * transformations, before all other transformations, so it cancels out * the alpha handling. It has the side effect negating the effect of * PNG_EXPAND_tRNS too: */ - png_ptr->transformations &= ~(PNG_BACKGROUND_EXPAND | PNG_ENCODE_ALPHA | - PNG_EXPAND_tRNS); + png_ptr->transformations &= ~(PNG_ENCODE_ALPHA | PNG_EXPAND_tRNS); png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; /* Kill the tRNS chunk itself too. Prior to 1.5.4 this did not happen * so transparency information would remain just so long as it wasn't @@ -1389,8 +1540,9 @@ * get.) This makes the behavior consistent from 1.5.4: */ png_ptr->num_trans = 0; } + } #endif /* STRIP_ALPHA supported, no COMPOSE */ #ifdef PNG_READ_ALPHA_MODE_SUPPORTED /* If the screen gamma is about 1.0 then the OPTIMIZE_ALPHA and ENCODE_ALPHA @@ -1410,53 +1562,21 @@ if (png_ptr->transformations & PNG_RGB_TO_GRAY) png_colorspace_set_rgb_coefficients(png_ptr); #endif -#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED -#if defined PNG_READ_EXPAND_SUPPORTED && defined PNG_READ_BACKGROUND_SUPPORTED - /* Detect gray background and attempt to enable optimization for - * gray --> RGB case. - * - * Note: if PNG_BACKGROUND_EXPAND is set and color_type is either RGB or - * RGB_ALPHA (in which case need_expand is superfluous anyway), the - * background color might actually be gray yet not be flagged as such. - * This is not a problem for the current code, which uses - * PNG_BACKGROUND_IS_GRAY only to decide when to do the - * png_do_gray_to_rgb() transformation. - * - * TODO: this code needs to be revised to avoid the complexity and - * interdependencies. The color type of the background should be recorded in - * png_set_background, along with the bit depth, then the code has a record - * of exactly what color space the background is currently in. - */ - if (png_ptr->transformations & PNG_BACKGROUND_EXPAND) - { - /* PNG_BACKGROUND_EXPAND: the background is in the file color space, so if - * the file was grayscale the background value is gray. - */ - if (!(png_ptr->color_type & PNG_COLOR_MASK_COLOR)) - png_ptr->mode |= PNG_BACKGROUND_IS_GRAY; - } + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + png_init_palette_transformations(png_ptr); - else if (png_ptr->transformations & PNG_COMPOSE) - { - /* PNG_COMPOSE: png_set_background was called with need_expand false, - * so the color is in the color space of the output or png_set_alpha_mode - * was called and the color is black. Ignore RGB_TO_GRAY because that - * happens before GRAY_TO_RGB. + else + png_init_rgb_transformations(png_ptr); + +#ifdef PNG_READ_BACKGROUND_SUPPORTED + /* Set up the background information if required. It is only used if + * PNG_COMPOSE is specified. */ - if (png_ptr->transformations & PNG_GRAY_TO_RGB) - { - if (png_ptr->background.red == png_ptr->background.green && - png_ptr->background.red == png_ptr->background.blue) - { - png_ptr->mode |= PNG_BACKGROUND_IS_GRAY; - png_ptr->background.gray = png_ptr->background.red; - } - } - } -#endif /* PNG_READ_EXPAND_SUPPORTED && PNG_READ_BACKGROUND_SUPPORTED */ -#endif /* PNG_READ_GRAY_TO_RGB_SUPPORTED */ + if (png_ptr->transformations & PNG_COMPOSE) + png_init_background_transformations(png_ptr); +#endif /* For indexed PNG data (PNG_COLOR_TYPE_PALETTE) many of the transformations * can be performed directly on the palette, and some (such as rgb to gray) * can be optimized inside the palette. This is particularly true of the @@ -1467,76 +1587,13 @@ * earlier and the palette stuff is actually handled on the first row. This * leads to the reported bug that the palette returned by png_get_PLTE is not * updated. */ - if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) - png_init_palette_transformations(png_ptr); - - else - png_init_rgb_transformations(png_ptr); - -#if defined(PNG_READ_BACKGROUND_SUPPORTED) && \ - defined(PNG_READ_EXPAND_16_SUPPORTED) - if ((png_ptr->transformations & PNG_EXPAND_16) && - (png_ptr->transformations & PNG_COMPOSE) && - !(png_ptr->transformations & PNG_BACKGROUND_EXPAND) && - png_ptr->bit_depth != 16) - { - /* TODO: fix this. Because the expand_16 operation is after the compose - * handling the background color must be 8, not 16, bits deep, but the - * application will supply a 16-bit value so reduce it here. - * - * The PNG_BACKGROUND_EXPAND code above does not expand to 16 bits at - * present, so that case is ok (until do_expand_16 is moved.) - * - * NOTE: this discards the low 16 bits of the user supplied background - * color, but until expand_16 works properly there is no choice! - */ -# define CHOP(x) (x)=((png_uint_16)PNG_DIV257(x)) - CHOP(png_ptr->background.red); - CHOP(png_ptr->background.green); - CHOP(png_ptr->background.blue); - CHOP(png_ptr->background.gray); -# 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); - } +#if 0 /* NYI */ + png_do_palette_transformations(png_ptr); #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 - * 1.5.4 betas simply to enable external critique and testing (i.e. to - * implement the new API quickly, without lots of internal changes.) - */ - #ifdef PNG_READ_GAMMA_SUPPORTED -# ifdef PNG_READ_BACKGROUND_SUPPORTED - /* Includes ALPHA_MODE */ - png_ptr->background_1 = png_ptr->background; -# endif - /* This needs to change - in the palette image case a whole set of tables are * built when it would be quicker to just calculate the correct value for * each palette entry directly. Also, the test is too tricky - why check * PNG_RGB_TO_GRAY if PNG_GAMMA is not set? The answer seems to be that @@ -1563,9 +1620,9 @@ )) || ((png_ptr->transformations & PNG_ENCODE_ALPHA) && png_gamma_significant(png_ptr->screen_gamma)) ) { - png_build_gamma_table(png_ptr, png_ptr->bit_depth); + png_build_gamma_tables(png_ptr, png_ptr->bit_depth); #ifdef PNG_READ_BACKGROUND_SUPPORTED if (png_ptr->transformations & PNG_COMPOSE) { @@ -1580,113 +1637,43 @@ "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. - */ - png_color back, back_1; + unsigned int i, num_palette = png_ptr->num_palette; + png_color back; + png_color_16 back_1 = png_ptr->background_1; png_colorp palette = png_ptr->palette; - int num_palette = png_ptr->num_palette; - int i; - if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_FILE) - { - - back.red = png_ptr->gamma_table[png_ptr->background.red]; - back.green = png_ptr->gamma_table[png_ptr->background.green]; - back.blue = png_ptr->gamma_table[png_ptr->background.blue]; - - back_1.red = png_ptr->gamma_to_1[png_ptr->background.red]; - back_1.green = png_ptr->gamma_to_1[png_ptr->background.green]; - back_1.blue = png_ptr->gamma_to_1[png_ptr->background.blue]; - } - else - { - png_fixed_point g, gs; - - switch (png_ptr->background_gamma_type) - { - case PNG_BACKGROUND_GAMMA_SCREEN: - g = (png_ptr->screen_gamma); - gs = PNG_FP_1; - break; - - case PNG_BACKGROUND_GAMMA_FILE: - g = png_reciprocal(png_ptr->colorspace.gamma); - gs = png_reciprocal2(png_ptr->colorspace.gamma, - png_ptr->screen_gamma); - break; - - case PNG_BACKGROUND_GAMMA_UNIQUE: - g = png_reciprocal(png_ptr->background_gamma); - gs = png_reciprocal2(png_ptr->background_gamma, - png_ptr->screen_gamma); - break; - default: - g = PNG_FP_1; /* back_1 */ - gs = PNG_FP_1; /* back */ - break; - } - - if (png_gamma_significant(gs)) - { - back.red = png_gamma_8bit_correct(png_ptr->background.red, - gs); - back.green = png_gamma_8bit_correct(png_ptr->background.green, - gs); - back.blue = png_gamma_8bit_correct(png_ptr->background.blue, - gs); - } - else - { back.red = (png_byte)png_ptr->background.red; back.green = (png_byte)png_ptr->background.green; back.blue = (png_byte)png_ptr->background.blue; - } - - if (png_gamma_significant(g)) - { - back_1.red = png_gamma_8bit_correct(png_ptr->background.red, - g); - back_1.green = png_gamma_8bit_correct( - png_ptr->background.green, g); - back_1.blue = png_gamma_8bit_correct(png_ptr->background.blue, - g); - } - - else - { - back_1.red = (png_byte)png_ptr->background.red; - back_1.green = (png_byte)png_ptr->background.green; - back_1.blue = (png_byte)png_ptr->background.blue; - } - } for (i = 0; i < num_palette; i++) { - if (i < (int)png_ptr->num_trans && - png_ptr->trans_alpha[i] != 0xff) + if (i < png_ptr->num_trans && png_ptr->trans_alpha[i] != 0xff) { if (png_ptr->trans_alpha[i] == 0) { palette[i] = back; } else /* if (png_ptr->trans_alpha[i] != 0xff) */ { - png_byte v, w; + png_uint_16 v, w; + unsigned int alpha = png_ptr->trans_alpha[i] * 257U; + unsigned int shift = png_ptr->gamma_shift; + unsigned int add = (shift > 0 ? 1U<<(shift-1) : 0); v = png_ptr->gamma_to_1[palette[i].red]; - png_composite(w, v, png_ptr->trans_alpha[i], back_1.red); - palette[i].red = png_ptr->gamma_from_1[w]; + png_composite_16(w, v, alpha, back_1.red); + palette[i].red = png_ptr->gamma_from_1[(w+add)>>shift]; v = png_ptr->gamma_to_1[palette[i].green]; - png_composite(w, v, png_ptr->trans_alpha[i], back_1.green); - palette[i].green = png_ptr->gamma_from_1[w]; + png_composite_16(w, v, alpha, back_1.green); + palette[i].green = png_ptr->gamma_from_1[(w+add)>>shift]; v = png_ptr->gamma_to_1[palette[i].blue]; - png_composite(w, v, png_ptr->trans_alpha[i], back_1.blue); - palette[i].blue = png_ptr->gamma_from_1[w]; + png_composite_16(w, v, alpha, back_1.blue); + palette[i].blue = png_ptr->gamma_from_1[(w+add)>>shift]; } } else { @@ -1703,93 +1690,8 @@ * transformations elsewhere. */ png_ptr->transformations &= ~(PNG_COMPOSE | PNG_GAMMA); } /* color_type == PNG_COLOR_TYPE_PALETTE */ - - /* if (png_ptr->background_gamma_type!=PNG_BACKGROUND_GAMMA_UNKNOWN) */ - else /* color_type != PNG_COLOR_TYPE_PALETTE */ - { - int gs_sig, g_sig; - png_fixed_point g = PNG_FP_1; /* Correction to linear */ - png_fixed_point gs = PNG_FP_1; /* Correction to screen */ - - switch (png_ptr->background_gamma_type) - { - case PNG_BACKGROUND_GAMMA_SCREEN: - g = png_ptr->screen_gamma; - /* gs = PNG_FP_1; */ - break; - - case PNG_BACKGROUND_GAMMA_FILE: - g = png_reciprocal(png_ptr->colorspace.gamma); - gs = png_reciprocal2(png_ptr->colorspace.gamma, - png_ptr->screen_gamma); - break; - - case PNG_BACKGROUND_GAMMA_UNIQUE: - g = png_reciprocal(png_ptr->background_gamma); - gs = png_reciprocal2(png_ptr->background_gamma, - png_ptr->screen_gamma); - break; - - default: - png_error(png_ptr, "invalid background gamma type"); - } - - g_sig = png_gamma_significant(g); - gs_sig = png_gamma_significant(gs); - - if (g_sig) - png_ptr->background_1.gray = png_gamma_correct(png_ptr, - png_ptr->background.gray, g); - - if (gs_sig) - png_ptr->background.gray = png_gamma_correct(png_ptr, - png_ptr->background.gray, gs); - - if ((png_ptr->background.red != png_ptr->background.green) || - (png_ptr->background.red != png_ptr->background.blue) || - (png_ptr->background.red != png_ptr->background.gray)) - { - /* RGB or RGBA with color background */ - if (g_sig) - { - png_ptr->background_1.red = png_gamma_correct(png_ptr, - png_ptr->background.red, g); - - png_ptr->background_1.green = png_gamma_correct(png_ptr, - png_ptr->background.green, g); - - png_ptr->background_1.blue = png_gamma_correct(png_ptr, - png_ptr->background.blue, g); - } - - if (gs_sig) - { - png_ptr->background.red = png_gamma_correct(png_ptr, - png_ptr->background.red, gs); - - png_ptr->background.green = png_gamma_correct(png_ptr, - png_ptr->background.green, gs); - - png_ptr->background.blue = png_gamma_correct(png_ptr, - png_ptr->background.blue, gs); - } - } - - else - { - /* GRAY, GRAY ALPHA, RGB, or RGBA with gray background */ - png_ptr->background_1.red = png_ptr->background_1.green - = png_ptr->background_1.blue = png_ptr->background_1.gray; - - png_ptr->background.red = png_ptr->background.green - = png_ptr->background.blue = png_ptr->background.gray; - } - - /* The background is now in screen gamma: */ - png_ptr->background_gamma_type = PNG_BACKGROUND_GAMMA_SCREEN; - } /* color_type != PNG_COLOR_TYPE_PALETTE */ }/* png_ptr->transformations & PNG_BACKGROUND */ else /* Transformation does not include PNG_BACKGROUND */ @@ -2234,9 +2136,9 @@ /* If gray -> RGB, do so now only if background is non-gray; else do later * for performance reasons */ if ((png_ptr->transformations & PNG_GRAY_TO_RGB) && - !(png_ptr->mode & PNG_BACKGROUND_IS_GRAY)) + !(png_ptr->flags & PNG_FLAG_BACKGROUND_IS_GRAY)) png_do_gray_to_rgb(row_info, png_ptr->row_buf + 1); #endif #if (defined PNG_READ_BACKGROUND_SUPPORTED) ||\ @@ -2319,9 +2221,9 @@ #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED /* NOTE: moved here in 1.5.4 (from much later in this list.) */ if ((png_ptr->transformations & PNG_GRAY_TO_RGB) && - (png_ptr->mode & PNG_BACKGROUND_IS_GRAY)) + (png_ptr->flags & PNG_FLAG_BACKGROUND_IS_GRAY)) png_do_gray_to_rgb(row_info, png_ptr->row_buf + 1); #endif #ifdef PNG_READ_INVERT_SUPPORTED @@ -3283,25 +3185,26 @@ (row_info->color_type & PNG_COLOR_MASK_ALPHA) != 0; if (row_info->bit_depth == 8) { -#ifdef PNG_READ_GAMMA_SUPPORTED /* Notice that gamma to/from 1 are not necessarily inverses (if * there is an overall gamma correction). Prior to 1.5.5 this code * checked the linearized values for equality; this doesn't match * the documentation, the original values must be checked. */ if (png_ptr->gamma_from_1 != NULL && png_ptr->gamma_to_1 != NULL) { + PNG_CONST unsigned int shift = 15 + png_ptr->gamma_shift; + PNG_CONST png_uint_32 add = 1U << (shift-1); png_bytep sp = row; png_bytep dp = row; png_uint_32 i; for (i = 0; i < row_width; i++) { - png_byte red = *(sp++); - png_byte green = *(sp++); - png_byte blue = *(sp++); + unsigned int red = *(sp++); + unsigned int green = *(sp++); + unsigned int blue = *(sp++); if (red != green || red != blue) { red = png_ptr->gamma_to_1[red]; @@ -3309,9 +3212,9 @@ blue = png_ptr->gamma_to_1[blue]; rgb_error |= 1; *(dp++) = png_ptr->gamma_from_1[ - (rc*red + gc*green + bc*blue + 16384)>>15]; + (rc*red + gc*green + bc*blue + add)>>shift]; } else { @@ -3320,9 +3223,9 @@ */ if (png_ptr->gamma_table != NULL) red = png_ptr->gamma_table[red]; - *(dp++) = red; + *(dp++) = (png_byte)red; } if (have_alpha) *(dp++) = *(sp++); @@ -3327,10 +3230,10 @@ if (have_alpha) *(dp++) = *(sp++); } } + else -#endif { png_bytep sp = row; png_bytep dp = row; png_uint_32 i; @@ -3343,12 +3246,9 @@ if (red != green || red != blue) { rgb_error |= 1; - /* NOTE: this is the historical approach which simply - * truncates the results. - */ - *(dp++) = (png_byte)((rc*red + gc*green + bc*blue)>>15); + *(dp++) = (png_byte)((rc*red+gc*green+bc*blue+16384)>>15); } else *(dp++) = red; @@ -3360,11 +3260,12 @@ } else /* RGB bit_depth == 16 */ { -#ifdef PNG_READ_GAMMA_SUPPORTED if (png_ptr->gamma_16_to_1 != NULL && png_ptr->gamma_16_from_1 != NULL) { + unsigned int shift = png_ptr->gamma_shift; + unsigned int add = (shift > 0 ? (1U << (shift-1)) : 0); png_bytep sp = row; png_bytep dp = row; png_uint_32 i; @@ -3378,28 +3279,25 @@ if (red == green && red == blue) { if (png_ptr->gamma_16_table != NULL) - w = png_ptr->gamma_16_table[(red&0xff) - >> png_ptr->gamma_shift][red>>8]; + w = png_ptr->gamma_16_table[(red+add) >> shift]; else w = red; } else { - png_uint_16 red_1 = png_ptr->gamma_16_to_1[(red&0xff) - >> png_ptr->gamma_shift][red>>8]; - png_uint_16 green_1 = - png_ptr->gamma_16_to_1[(green&0xff) >> - png_ptr->gamma_shift][green>>8]; - png_uint_16 blue_1 = png_ptr->gamma_16_to_1[(blue&0xff) - >> png_ptr->gamma_shift][blue>>8]; + png_uint_16 red_1 = png_ptr->gamma_16_to_1[(red+add) + >> shift]; + png_uint_16 green_1 = png_ptr->gamma_16_to_1[(green+add) + >> shift]; + png_uint_16 blue_1 = png_ptr->gamma_16_to_1[(blue+add) + >> shift]; png_uint_16 gray16 = (png_uint_16)((rc*red_1 + gc*green_1 + bc*blue_1 + 16384)>>15); - w = png_ptr->gamma_16_from_1[(gray16&0xff) >> - png_ptr->gamma_shift][gray16 >> 8]; + w = png_ptr->gamma_16_from_1[(gray16+add) >> shift]; rgb_error |= 1; } *(dp++) = (png_byte)((w>>8) & 0xff); @@ -3411,10 +3309,10 @@ *(dp++) = *(sp++); } } } + else -#endif { png_bytep sp = row; png_bytep dp = row; png_uint_32 i; @@ -3433,10 +3331,9 @@ /* 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) >> - 15); + gray16 = (png_uint_16)((rc*red+gc*green+bc*blue+16384) >> 15); *(dp++) = (png_byte)((gray16>>8) & 0xff); *(dp++) = (png_byte)(gray16 & 0xff); if (have_alpha) @@ -3526,23 +3423,21 @@ */ void /* PRIVATE */ png_do_compose(png_row_infop row_info, png_bytep row, png_structrp png_ptr) { -#ifdef PNG_READ_GAMMA_SUPPORTED png_const_bytep gamma_table = png_ptr->gamma_table; png_const_bytep gamma_from_1 = png_ptr->gamma_from_1; - png_const_bytep gamma_to_1 = png_ptr->gamma_to_1; - png_const_uint_16pp gamma_16 = png_ptr->gamma_16_table; - png_const_uint_16pp gamma_16_from_1 = png_ptr->gamma_16_from_1; - png_const_uint_16pp gamma_16_to_1 = png_ptr->gamma_16_to_1; - int gamma_shift = png_ptr->gamma_shift; - int optimize = (png_ptr->flags & PNG_FLAG_OPTIMIZE_ALPHA) != 0; -#endif + png_const_uint_16p gamma_to_1 = png_ptr->gamma_to_1; + png_const_uint_16p gamma_16 = png_ptr->gamma_16_table; + png_const_uint_16p gamma_16_from_1 = png_ptr->gamma_16_from_1; + png_const_uint_16p gamma_16_to_1 = png_ptr->gamma_16_to_1; + PNG_CONST unsigned int shift = png_ptr->gamma_shift; + PNG_CONST unsigned int add = (shift > 0 ? 1U<<(shift-1) : 0); + PNG_CONST int optimize = (png_ptr->flags & PNG_FLAG_OPTIMIZE_ALPHA) != 0; png_bytep sp; png_uint_32 i; png_uint_32 row_width = row_info->width; - int shift; png_debug(1, "in png_do_compose"); { @@ -3553,167 +3448,166 @@ switch (row_info->bit_depth) { case 1: { + int bit_shift = 7; sp = row; - shift = 7; for (i = 0; i < row_width; i++) { - if ((png_uint_16)((*sp >> shift) & 0x01) + if ((png_uint_16)((*sp >> bit_shift) & 0x01) == png_ptr->trans_color.gray) { - unsigned int tmp = *sp & (0x7f7f >> (7 - shift)); - tmp |= png_ptr->background.gray << shift; + unsigned int tmp = *sp & (0x7f7f >> (7 - bit_shift)); + tmp |= png_ptr->background.gray << bit_shift; *sp = (png_byte)(tmp & 0xff); } - if (!shift) + if (!bit_shift) { - shift = 7; + bit_shift = 7; sp++; } else - shift--; + bit_shift--; } break; } case 2: { -#ifdef PNG_READ_GAMMA_SUPPORTED +#if 0 if (gamma_table != NULL) { + int bit_shift = 6; sp = row; - shift = 6; for (i = 0; i < row_width; i++) { - if ((png_uint_16)((*sp >> shift) & 0x03) + if ((png_uint_16)((*sp >> bit_shift) & 0x03) == png_ptr->trans_color.gray) { - unsigned int tmp = *sp & (0x3f3f >> (6 - shift)); - tmp |= png_ptr->background.gray << shift; + unsigned int tmp = *sp & (0x3f3f >> (6 - bit_shift)); + tmp |= png_ptr->background.gray << bit_shift; *sp = (png_byte)(tmp & 0xff); } else { - unsigned int p = (*sp >> shift) & 0x03; + unsigned int p = (*sp >> bit_shift) & 0x03; unsigned int g = (gamma_table [p | (p << 2) | (p << 4) | (p << 6)] >> 6) & 0x03; - unsigned int tmp = *sp & (0x3f3f >> (6 - shift)); - tmp |= g << shift; + unsigned int tmp = *sp & (0x3f3f >> (6 - bit_shift)); + tmp |= g << bit_shift; *sp = (png_byte)(tmp & 0xff); } - if (!shift) + if (!bit_shift) { - shift = 6; + bit_shift = 6; sp++; } else - shift -= 2; + bit_shift -= 2; } } else #endif { + int bit_shift = 6; sp = row; - shift = 6; for (i = 0; i < row_width; i++) { - if ((png_uint_16)((*sp >> shift) & 0x03) + if ((png_uint_16)((*sp >> bit_shift) & 0x03) == png_ptr->trans_color.gray) { - unsigned int tmp = *sp & (0x3f3f >> (6 - shift)); - tmp |= png_ptr->background.gray << shift; + unsigned int tmp = *sp & (0x3f3f >> (6 - bit_shift)); + tmp |= png_ptr->background.gray << bit_shift; *sp = (png_byte)(tmp & 0xff); } - if (!shift) + if (!bit_shift) { - shift = 6; + bit_shift = 6; sp++; } else - shift -= 2; + bit_shift -= 2; } } break; } case 4: { -#ifdef PNG_READ_GAMMA_SUPPORTED +#if 0 if (gamma_table != NULL) { + int bit_shift = 4; sp = row; - shift = 4; for (i = 0; i < row_width; i++) { - if ((png_uint_16)((*sp >> shift) & 0x0f) + if ((png_uint_16)((*sp >> bit_shift) & 0x0f) == png_ptr->trans_color.gray) { - unsigned int tmp = *sp & (0xf0f >> (4 - shift)); - tmp |= png_ptr->background.gray << shift; + unsigned int tmp = *sp & (0xf0f >> (4 - bit_shift)); + tmp |= png_ptr->background.gray << bit_shift; *sp = (png_byte)(tmp & 0xff); } else { - unsigned int p = (*sp >> shift) & 0x0f; + unsigned int p = (*sp >> bit_shift) & 0x0f; unsigned int g = (gamma_table[p | (p << 4)] >> 4) & 0x0f; - unsigned int tmp = *sp & (0xf0f >> (4 - shift)); - tmp |= g << shift; + unsigned int tmp = *sp & (0xf0f >> (4 - bit_shift)); + tmp |= g << bit_shift; *sp = (png_byte)(tmp & 0xff); } - if (!shift) + if (!bit_shift) { - shift = 4; + bit_shift = 4; sp++; } else - shift -= 4; + bit_shift -= 4; } } else #endif { + int bit_shift = 4; sp = row; - shift = 4; for (i = 0; i < row_width; i++) { - if ((png_uint_16)((*sp >> shift) & 0x0f) + if ((png_uint_16)((*sp >> bit_shift) & 0x0f) == png_ptr->trans_color.gray) { - unsigned int tmp = *sp & (0xf0f >> (4 - shift)); - tmp |= png_ptr->background.gray << shift; + unsigned int tmp = *sp & (0xf0f >> (4 - bit_shift)); + tmp |= png_ptr->background.gray << bit_shift; *sp = (png_byte)(tmp & 0xff); } - if (!shift) + if (!bit_shift) { - shift = 4; + bit_shift = 4; sp++; } else - shift -= 4; + bit_shift -= 4; } } break; } case 8: { -#ifdef PNG_READ_GAMMA_SUPPORTED if (gamma_table != NULL) { sp = row; for (i = 0; i < row_width; i++, sp++) @@ -3724,10 +3618,10 @@ else *sp = gamma_table[*sp]; } } + else -#endif { sp = row; for (i = 0; i < row_width; i++, sp++) { @@ -3739,9 +3633,8 @@ } case 16: { -#ifdef PNG_READ_GAMMA_SUPPORTED if (gamma_16 != NULL) { sp = row; for (i = 0; i < row_width; i++, sp += 2) @@ -3760,9 +3653,9 @@ } else { - v = gamma_16[*(sp + 1) >> gamma_shift][*sp]; + v = gamma_16[(v+add) >> shift]; *sp = (png_byte)((v >> 8) & 0xff); *(sp + 1) = (png_byte)(v & 0xff); } } @@ -3766,10 +3659,10 @@ *(sp + 1) = (png_byte)(v & 0xff); } } } + else -#endif { sp = row; for (i = 0; i < row_width; i++, sp += 2) { @@ -3798,9 +3691,8 @@ case PNG_COLOR_TYPE_RGB: { if (row_info->bit_depth == 8) { -#ifdef PNG_READ_GAMMA_SUPPORTED if (gamma_table != NULL) { sp = row; for (i = 0; i < row_width; i++, sp += 3) @@ -3821,10 +3713,10 @@ *(sp + 2) = gamma_table[*(sp + 2)]; } } } + else -#endif { sp = row; for (i = 0; i < row_width; i++, sp += 3) { @@ -3840,9 +3732,8 @@ } } else /* if (row_info->bit_depth == 16) */ { -#ifdef PNG_READ_GAMMA_SUPPORTED if (gamma_16 != NULL) { sp = row; for (i = 0; i < row_width; i++, sp += 6) @@ -3872,25 +3763,24 @@ } else { - png_uint_16 v = gamma_16[*(sp + 1) >> gamma_shift][*sp]; + png_uint_16 v = gamma_16[(r+add) >> shift]; *sp = (png_byte)((v >> 8) & 0xff); *(sp + 1) = (png_byte)(v & 0xff); - v = gamma_16[*(sp + 3) >> gamma_shift][*(sp + 2)]; + v = gamma_16[(g+add) >> shift]; *(sp + 2) = (png_byte)((v >> 8) & 0xff); *(sp + 3) = (png_byte)(v & 0xff); - v = gamma_16[*(sp + 5) >> gamma_shift][*(sp + 4)]; + v = gamma_16[(b+add) >> shift]; *(sp + 4) = (png_byte)((v >> 8) & 0xff); *(sp + 5) = (png_byte)(v & 0xff); } } } else -#endif { sp = row; for (i = 0; i < row_width; i++, sp += 6) { @@ -3925,9 +3815,8 @@ case PNG_COLOR_TYPE_GRAY_ALPHA: { if (row_info->bit_depth == 8) { -#ifdef PNG_READ_GAMMA_SUPPORTED if (gamma_to_1 != NULL && gamma_from_1 != NULL && gamma_table != NULL) { sp = row; @@ -3945,20 +3834,26 @@ } else { - png_byte v, w; + unsigned int v, w; v = gamma_to_1[*sp]; - png_composite(w, v, a, png_ptr->background_1.gray); + png_composite_16(w, v, 257*a, + png_ptr->background_1.gray); + if (!optimize) - w = gamma_from_1[w]; - *sp = w; + w = gamma_from_1[(w+add)>>shift]; + + else /* alpha pixels linear and approximate */ + w = PNG_DIV257(w); + + *sp = (png_byte)w; } } } + else -#endif { sp = row; for (i = 0; i < row_width; i++, sp += 2) { @@ -3971,11 +3866,11 @@ png_composite(*sp, *sp, a, png_ptr->background.gray); } } } + else /* if (png_ptr->bit_depth == 16) */ { -#ifdef PNG_READ_GAMMA_SUPPORTED if (gamma_16 != NULL && gamma_16_from_1 != NULL && gamma_16_to_1 != NULL) { sp = row; @@ -3987,9 +3882,9 @@ if (a == (png_uint_16)0xffff) { png_uint_16 v; - v = gamma_16[*(sp + 1) >> gamma_shift][*sp]; + v = gamma_16[((sp[0]<<8)+sp[1]+add) >> shift]; *sp = (png_byte)((v >> 8) & 0xff); *(sp + 1) = (png_byte)(v & 0xff); } @@ -4004,14 +3899,17 @@ else { png_uint_16 g, v, w; - g = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp]; + g = gamma_16_to_1[((sp[0]<<8)+sp[1]+add) >> shift]; png_composite_16(v, g, a, png_ptr->background_1.gray); - if (optimize) - w = v; + + if (!optimize) + w = gamma_16_from_1[(v+add) >> shift]; + else - w = gamma_16_from_1[(v&0xff) >> gamma_shift][v >> 8]; + w = v; + *sp = (png_byte)((w >> 8) & 0xff); *(sp + 1) = (png_byte)(w & 0xff); } } @@ -4015,10 +3913,10 @@ *(sp + 1) = (png_byte)(w & 0xff); } } } + else -#endif { sp = row; for (i = 0; i < row_width; i++, sp += 4) { @@ -4050,9 +3948,8 @@ case PNG_COLOR_TYPE_RGB_ALPHA: { if (row_info->bit_depth == 8) { -#ifdef PNG_READ_GAMMA_SUPPORTED if (gamma_to_1 != NULL && gamma_from_1 != NULL && gamma_table != NULL) { sp = row; @@ -4076,29 +3973,51 @@ } else { - png_byte v, w; + unsigned int v, w; + unsigned int alpha = a * 257U; v = gamma_to_1[*sp]; - png_composite(w, v, a, png_ptr->background_1.red); - if (!optimize) w = gamma_from_1[w]; - *sp = w; + png_composite_16(w, v, alpha, + png_ptr->background_1.red); + + if (!optimize) + w = gamma_from_1[(w+add)>>shift]; + + else + w = PNG_DIV257(w); + + *sp = (png_byte)w; v = gamma_to_1[*(sp + 1)]; - png_composite(w, v, a, png_ptr->background_1.green); - if (!optimize) w = gamma_from_1[w]; - *(sp + 1) = w; + png_composite_16(w, v, alpha, + png_ptr->background_1.green); + + if (!optimize) + w = gamma_from_1[(w+add)>>shift]; + + else + w = PNG_DIV257(w); + + *(sp + 1) = (png_byte)w; v = gamma_to_1[*(sp + 2)]; - png_composite(w, v, a, png_ptr->background_1.blue); - if (!optimize) w = gamma_from_1[w]; - *(sp + 2) = w; + png_composite_16(w, v, alpha, + png_ptr->background_1.blue); + + if (!optimize) + w = gamma_from_1[(w+add)>>shift]; + + else + w = PNG_DIV257(w); + + *(sp + 2) = (png_byte)w; } } } + else -#endif { sp = row; for (i = 0; i < row_width; i++, sp += 4) { @@ -4123,11 +4042,11 @@ } } } } + else /* if (row_info->bit_depth == 16) */ { -#ifdef PNG_READ_GAMMA_SUPPORTED if (gamma_16 != NULL && gamma_16_from_1 != NULL && gamma_16_to_1 != NULL) { sp = row; @@ -4139,17 +4058,17 @@ if (a == (png_uint_16)0xffff) { png_uint_16 v; - v = gamma_16[*(sp + 1) >> gamma_shift][*sp]; + v = gamma_16[((sp[0]<<8)+sp[1]+add) >> shift]; *sp = (png_byte)((v >> 8) & 0xff); *(sp + 1) = (png_byte)(v & 0xff); - v = gamma_16[*(sp + 3) >> gamma_shift][*(sp + 2)]; + v = gamma_16[((sp[2]<<8)+sp[3]+add) >> shift]; *(sp + 2) = (png_byte)((v >> 8) & 0xff); *(sp + 3) = (png_byte)(v & 0xff); - v = gamma_16[*(sp + 5) >> gamma_shift][*(sp + 4)]; + v = gamma_16[((sp[4]<<8)+sp[5]+add) >> shift]; *(sp + 4) = (png_byte)((v >> 8) & 0xff); *(sp + 5) = (png_byte)(v & 0xff); } @@ -4170,39 +4089,39 @@ else { png_uint_16 v, w; - v = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp]; + v = gamma_16_to_1[((sp[0]<<8)+sp[1]+add) >> shift]; png_composite_16(w, v, a, png_ptr->background_1.red); + if (!optimize) - w = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >> - 8]; + w = gamma_16_from_1[(w+add) >> shift]; + *sp = (png_byte)((w >> 8) & 0xff); *(sp + 1) = (png_byte)(w & 0xff); - v = gamma_16_to_1[*(sp + 3) >> gamma_shift][*(sp + 2)]; + v = gamma_16_to_1[((sp[2]<<8)+sp[3]+add) >> shift]; png_composite_16(w, v, a, png_ptr->background_1.green); + if (!optimize) - w = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >> - 8]; + w = gamma_16_from_1[(w+add) >> shift]; *(sp + 2) = (png_byte)((w >> 8) & 0xff); *(sp + 3) = (png_byte)(w & 0xff); - v = gamma_16_to_1[*(sp + 5) >> gamma_shift][*(sp + 4)]; + v = gamma_16_to_1[((sp[4]<<8)+sp[5]+add) >> shift]; png_composite_16(w, v, a, png_ptr->background_1.blue); + if (!optimize) - w = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >> - 8]; + w = gamma_16_from_1[(w+add) >> shift]; *(sp + 4) = (png_byte)((w >> 8) & 0xff); *(sp + 5) = (png_byte)(w & 0xff); } } } else -#endif { sp = row; for (i = 0; i < row_width; i++, sp += 8) { @@ -4267,18 +4186,24 @@ void /* PRIVATE */ png_do_gamma(png_row_infop row_info, png_bytep row, png_structrp png_ptr) { png_const_bytep gamma_table = png_ptr->gamma_table; - png_const_uint_16pp gamma_16_table = png_ptr->gamma_16_table; - int gamma_shift = png_ptr->gamma_shift; + png_const_uint_16p gamma_16_table = png_ptr->gamma_16_table; + int shift = png_ptr->gamma_shift; + int add = (shift > 0 ? 1U << (shift-1) : 0); png_bytep sp; png_uint_32 i; png_uint_32 row_width=row_info->width; png_debug(1, "in png_do_gamma"); - if (((row_info->bit_depth <= 8 && gamma_table != NULL) || + /* Prior to libpng 1.7.0 this code would attempt to gamma correct 2 and 4 bit + * gray level values, the results are ridiculously inaccurate. In 1.7.0 the + * code is removed and a warning is introduced to catch cases where an + * application might actually try it. + */ + if (((row_info->bit_depth == 8 && gamma_table != NULL) || (row_info->bit_depth == 16 && gamma_16_table != NULL))) { switch (row_info->color_type) { @@ -4304,19 +4229,19 @@ for (i = 0; i < row_width; i++) { png_uint_16 v; - v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; + v = gamma_16_table[((sp[0]<<8)+sp[1]+add) >> shift]; *sp = (png_byte)((v >> 8) & 0xff); *(sp + 1) = (png_byte)(v & 0xff); sp += 2; - v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; + v = gamma_16_table[((sp[0]<<8)+sp[1]+add) >> shift]; *sp = (png_byte)((v >> 8) & 0xff); *(sp + 1) = (png_byte)(v & 0xff); sp += 2; - v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; + v = gamma_16_table[((sp[0]<<8)+sp[1]+add) >> shift]; *sp = (png_byte)((v >> 8) & 0xff); *(sp + 1) = (png_byte)(v & 0xff); sp += 2; } @@ -4348,19 +4273,21 @@ { sp = row; for (i = 0; i < row_width; i++) { - png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; + png_uint_16 v; + + v = gamma_16_table[((sp[0]<<8)+sp[1]+add) >> shift]; *sp = (png_byte)((v >> 8) & 0xff); *(sp + 1) = (png_byte)(v & 0xff); sp += 2; - v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; + v = gamma_16_table[((sp[0]<<8)+sp[1]+add) >> shift]; *sp = (png_byte)((v >> 8) & 0xff); *(sp + 1) = (png_byte)(v & 0xff); sp += 2; - v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; + v = gamma_16_table[((sp[0]<<8)+sp[1]+add) >> shift]; *sp = (png_byte)((v >> 8) & 0xff); *(sp + 1) = (png_byte)(v & 0xff); sp += 4; } @@ -4384,9 +4311,11 @@ { sp = row; for (i = 0; i < row_width; i++) { - png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; + png_uint_16 v; + + v = gamma_16_table[((sp[0]<<8)+sp[1]+add) >> shift]; *sp = (png_byte)((v >> 8) & 0xff); *(sp + 1) = (png_byte)(v & 0xff); sp += 4; } @@ -4395,42 +4324,9 @@ } case PNG_COLOR_TYPE_GRAY: { - if (row_info->bit_depth == 2) - { - sp = row; - for (i = 0; i < row_width; i += 4) - { - int a = *sp & 0xc0; - int b = *sp & 0x30; - int c = *sp & 0x0c; - int d = *sp & 0x03; - - *sp = (png_byte)( - ((((int)gamma_table[a|(a>>2)|(a>>4)|(a>>6)]) ) & 0xc0)| - ((((int)gamma_table[(b<<2)|b|(b>>2)|(b>>4)])>>2) & 0x30)| - ((((int)gamma_table[(c<<4)|(c<<2)|c|(c>>2)])>>4) & 0x0c)| - ((((int)gamma_table[(d<<6)|(d<<4)|(d<<2)|d])>>6) )); - sp++; - } - } - - if (row_info->bit_depth == 4) - { - sp = row; - for (i = 0; i < row_width; i += 2) - { - int msb = *sp & 0xf0; - int lsb = *sp & 0x0f; - - *sp = (png_byte)((((int)gamma_table[msb | (msb >> 4)]) & 0xf0) - | (((int)gamma_table[(lsb << 4) | lsb]) >> 4)); - sp++; - } - } - - else if (row_info->bit_depth == 8) + if (row_info->bit_depth == 8) { sp = row; for (i = 0; i < row_width; i++) { @@ -4438,14 +4334,16 @@ sp++; } } - else if (row_info->bit_depth == 16) + else /*row_info->bit_depth == 16 */ { sp = row; for (i = 0; i < row_width; i++) { - png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; + png_uint_16 v; + + v = gamma_16_table[((sp[0]<<8)+sp[1]+add) >> shift]; *sp = (png_byte)((v >> 8) & 0xff); *(sp + 1) = (png_byte)(v & 0xff); sp += 2; } @@ -4473,33 +4371,35 @@ png_debug(1, "in png_do_encode_alpha"); if (row_info->color_type & PNG_COLOR_MASK_ALPHA) { + PNG_CONST unsigned int shift = png_ptr->gamma_shift; + PNG_CONST unsigned int add = (shift > 0 ? 1U<<(shift-1) : 0); + if (row_info->bit_depth == 8) { - PNG_CONST png_bytep table = png_ptr->gamma_from_1; + PNG_CONST png_bytep gamma_from_1 = png_ptr->gamma_from_1; - if (table != NULL) + if (gamma_from_1 != NULL) { PNG_CONST int step = (row_info->color_type & PNG_COLOR_MASK_COLOR) ? 4 : 2; /* The alpha channel is the last component: */ row += step - 1; for (; row_width > 0; --row_width, row += step) - *row = table[*row]; + *row = gamma_from_1[(257U**row+add)>>shift]; return; } } else if (row_info->bit_depth == 16) { - PNG_CONST png_uint_16pp table = png_ptr->gamma_16_from_1; - PNG_CONST int gamma_shift = png_ptr->gamma_shift; + PNG_CONST png_uint_16p gamma_16_from_1 = png_ptr->gamma_16_from_1; - if (table != NULL) + if (gamma_16_from_1 != NULL) { PNG_CONST int step = (row_info->color_type & PNG_COLOR_MASK_COLOR) ? 8 : 4; @@ -4509,9 +4409,9 @@ for (; row_width > 0; --row_width, row += step) { png_uint_16 v; - v = table[*(row + 1) >> gamma_shift][*row]; + v = gamma_16_from_1[((row[0]<<8)+row[1]+add) >> shift]; *row = (png_byte)((v >> 8) & 0xff); *(row + 1) = (png_byte)(v & 0xff); } diff -ru4NwbB libpng-1.6.0beta33/pngrutil.c libpng-1.7.0alpha02/pngrutil.c --- libpng-1.6.0beta33/pngrutil.c 2012-12-15 08:22:35.082722722 -0600 +++ libpng-1.7.0alpha02/pngrutil.c 2012-12-16 19:27:55.827200698 -0600 @@ -1,8 +1,8 @@ /* pngrutil.c - utilities to read a PNG file * - * Last changed in libpng 1.6.0 [(PENDING RELEASE)] + * Last changed in libpng 1.7.0 [(PENDING RELEASE)] * Copyright (c) 1998-2012 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.) * @@ -561,9 +561,9 @@ * limited only by the maximum chunk size. */ png_alloc_size_t limit = PNG_SIZE_MAX; -# ifdef PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED +# ifdef PNG_SET_USER_LIMITS_SUPPOPRTED if (png_ptr->user_chunk_malloc_max > 0 && png_ptr->user_chunk_malloc_max < limit) limit = png_ptr->user_chunk_malloc_max; # elif PNG_USER_CHUNK_MALLOC_MAX > 0 @@ -1581,9 +1581,10 @@ } if (--png_ptr->user_chunk_cache_max == 1) { - png_warning(png_ptr, "No space in chunk cache for sPLT"); + /* Warn the first time */ + png_chunk_benign_error(png_ptr, "chunk cache full"); png_crc_finish(png_ptr, length); return; } } @@ -1831,8 +1832,10 @@ * png_info. Fix this. */ png_set_tRNS(png_ptr, info_ptr, readbuf, png_ptr->num_trans, &(png_ptr->trans_color)); + + png_ptr->trans_alpha = info_ptr->trans_alpha; } #endif #ifdef PNG_READ_bKGD_SUPPORTED @@ -2369,9 +2372,9 @@ if (--png_ptr->user_chunk_cache_max == 1) { png_crc_finish(png_ptr, length); - png_chunk_benign_error(png_ptr, "no space in chunk cache"); + png_chunk_benign_error(png_ptr, "chunk cache full"); return; } } #endif @@ -2448,9 +2451,9 @@ if (--png_ptr->user_chunk_cache_max == 1) { png_crc_finish(png_ptr, length); - png_chunk_benign_error(png_ptr, "no space in chunk cache"); + png_chunk_benign_error(png_ptr, "chunk cache full"); return; } } #endif @@ -2557,9 +2560,9 @@ if (--png_ptr->user_chunk_cache_max == 1) { png_crc_finish(png_ptr, length); - png_chunk_benign_error(png_ptr, "no space in chunk cache"); + png_chunk_benign_error(png_ptr, "chunk cache full"); return; } } #endif @@ -2697,9 +2700,9 @@ png_free(png_ptr, png_ptr->unknown_chunk.data); png_ptr->unknown_chunk.data = NULL; } -# ifdef PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED +# ifdef PNG_SET_USER_LIMITS_SUPPOPRTED if (png_ptr->user_chunk_malloc_max > 0 && png_ptr->user_chunk_malloc_max < limit) limit = png_ptr->user_chunk_malloc_max; @@ -2892,9 +2895,9 @@ switch (png_ptr->user_chunk_cache_max) { case 2: png_ptr->user_chunk_cache_max = 1; - png_chunk_benign_error(png_ptr, "no space in chunk cache"); + png_chunk_benign_error(png_ptr, "chunk cache full"); /* FALL THROUGH */ case 1: /* NOTE: prior to 1.6.0 this case resulted in an unknown critical * chunk being skipped, now there will be a hard error below. @@ -3869,9 +3872,9 @@ * implementations required to reverse the filtering of PNG rows. Reversing * the filter is the first transformation performed on the row data. It is * performed in place, therefore an implementation can be selected based on * the image pixel format. If the implementation depends on image width then - * take care to ensure that it works corretly if the image is interlaced - + * take care to ensure that it works correctly if the image is interlaced - * interlacing causes the actual row width to vary. */ { unsigned int bpp = (pp->pixel_depth + 7) >> 3; @@ -4369,9 +4372,9 @@ if (row_bytes > (png_uint_32)65536L) png_error(png_ptr, "This image requires a row greater than 64KB"); #endif - if (row_bytes + 48 > png_ptr->old_big_row_buf_size) + if (row_bytes + 48 > png_ptr->big_row_buf_size) { png_free(png_ptr, png_ptr->big_row_buf); png_free(png_ptr, png_ptr->big_prev_row); @@ -4406,9 +4409,9 @@ /* Use 31 bytes of padding before and 17 bytes after row_buf. */ png_ptr->row_buf = png_ptr->big_row_buf + 31; png_ptr->prev_row = png_ptr->big_prev_row + 31; #endif - png_ptr->old_big_row_buf_size = row_bytes + 48; + png_ptr->big_row_buf_size = row_bytes + 48; } #ifdef PNG_MAX_MALLOC_64K if (png_ptr->rowbytes > 65535) diff -ru4NwbB libpng-1.6.0beta33/pngset.c libpng-1.7.0alpha02/pngset.c --- libpng-1.6.0beta33/pngset.c 2012-12-15 08:22:35.092114465 -0600 +++ libpng-1.7.0alpha02/pngset.c 2012-12-16 19:27:55.836472392 -0600 @@ -1,8 +1,8 @@ /* pngset.c - storage of image information into info struct * - * Last changed in libpng 1.6.0 [(PENDING RELEASE)] + * Last changed in libpng 1.7.0 [(PENDING RELEASE)] * Copyright (c) 1998-2012 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.) * @@ -909,54 +909,91 @@ if (png_ptr == NULL || info_ptr == NULL) return; - if (trans_alpha != NULL) + if (info_ptr->color_type & PNG_COLOR_MASK_ALPHA) + png_chunk_report(png_ptr, + "png_set_tRNS: invalid on PNG with alpha channel", PNG_CHUNK_ERROR); + + else if (info_ptr->color_type & PNG_COLOR_MASK_PALETTE) { - /* It may not actually be necessary to set png_ptr->trans_alpha here; - * we do it for backward compatibility with the way the png_handle_tRNS - * function used to do the allocation. - * - * 1.6.0: The above statement is incorrect; png_handle_tRNS effectively - * relies on png_set_tRNS storing the information in png_struct - * (otherwise it won't be there for the code in pngrtran.c). - */ + int max_num; + /* Free the old data; num_trans 0 can be used to kill the tRNS */ png_free_data(png_ptr, info_ptr, PNG_FREE_TRNS, 0); - /* Changed from num_trans to PNG_MAX_PALETTE_LENGTH in version 1.2.1 */ - png_ptr->trans_alpha = info_ptr->trans_alpha = png_voidcast(png_bytep, - png_malloc(png_ptr, PNG_MAX_PALETTE_LENGTH)); + /* Do this just in case the old data was not owned by libpng: */ + info_ptr->valid &= ~PNG_INFO_tRNS; + info_ptr->trans_alpha = NULL; + info_ptr->num_trans = 0; + + /* Expect png_set_PLTE to happen before png_set_tRNS, so num_palette will + * be set, but this is not a requirement of the API. + */ + if (png_ptr->num_palette) + max_num = png_ptr->num_palette; + + else + max_num = 1 << png_ptr->bit_depth; + + if (num_trans > max_num) + { + png_chunk_report(png_ptr, "png_set_tRNS: num_trans too large", + PNG_CHUNK_ERROR); + /* If control returns simply limit it; the behavior prior to 1.7 was to + * issue a warning and skip the palette in png_write_tRNS. + */ + num_trans = max_num; + } + + /* But only attempt a malloc if there is something to do; so the app can + * set a tRNS array then later delete it. + */ + if (num_trans > 0 && trans_alpha != NULL) + { + /* Changed from num_trans to PNG_MAX_PALETTE_LENGTH in version 1.2.1, + * this avoids issues where a palette image contains out of range + * indices. + */ + info_ptr->trans_alpha = png_voidcast(png_bytep, png_malloc(png_ptr, + PNG_MAX_PALETTE_LENGTH)); + info_ptr->free_me |= PNG_FREE_TRNS; - if (num_trans > 0 && num_trans <= PNG_MAX_PALETTE_LENGTH) - memcpy(info_ptr->trans_alpha, trans_alpha, (png_size_t)num_trans); + memcpy(info_ptr->trans_alpha, trans_alpha, num_trans); + info_ptr->valid |= PNG_INFO_tRNS; + info_ptr->num_trans = (png_uint_16)num_trans; /* SAFE */ + } } + else /* not a PALETTE image */ + { + /* Invalidate any prior transparent color, set num_trans too, it is not + * used internally in this case but png_get_tRNS still returns it. + */ + info_ptr->valid &= ~PNG_INFO_tRNS; + info_ptr->num_trans = 0; /* for png_get_tRNS */ + if (trans_color != NULL) { int sample_max = (1 << info_ptr->bit_depth); if ((info_ptr->color_type == PNG_COLOR_TYPE_GRAY && - trans_color->gray > sample_max) || + trans_color->gray <= sample_max) || (info_ptr->color_type == PNG_COLOR_TYPE_RGB && - (trans_color->red > sample_max || - trans_color->green > sample_max || - trans_color->blue > sample_max))) - png_warning(png_ptr, - "tRNS chunk has out-of-range samples for bit_depth"); - + trans_color->red <= sample_max && + trans_color->green <= sample_max && + trans_color->blue <= sample_max)) + { info_ptr->trans_color = *trans_color; - - if (num_trans == 0) - num_trans = 1; + info_ptr->valid |= PNG_INFO_tRNS; + info_ptr->num_trans = 1; /* for png_get_tRNS */ } - info_ptr->num_trans = (png_uint_16)num_trans; - - if (num_trans != 0) - { - info_ptr->valid |= PNG_INFO_tRNS; - info_ptr->free_me |= PNG_FREE_TRNS; + else + png_chunk_report(png_ptr, + "tRNS chunk has out-of-range samples for bit_depth", + PNG_CHUNK_ERROR); + } } } #endif @@ -1486,29 +1523,29 @@ /* Images with dimensions larger than these limits will be * rejected by png_set_IHDR(). To accept any PNG datastream * regardless of dimensions, set both limits to 0x7ffffffL. */ - if (png_ptr == NULL) - return; - + if (png_ptr != NULL) + { png_ptr->user_width_max = user_width_max; png_ptr->user_height_max = user_height_max; } +} /* This function was added to libpng 1.4.0 */ void PNGAPI png_set_chunk_cache_max (png_structrp png_ptr, png_uint_32 user_chunk_cache_max) { - if (png_ptr) + if (png_ptr != NULL) png_ptr->user_chunk_cache_max = user_chunk_cache_max; } /* This function was added to libpng 1.4.1 */ void PNGAPI png_set_chunk_malloc_max (png_structrp png_ptr, png_alloc_size_t user_chunk_malloc_max) { - if (png_ptr) + if (png_ptr != NULL) png_ptr->user_chunk_malloc_max = user_chunk_malloc_max; } #endif /* ?PNG_SET_USER_LIMITS_SUPPORTED */ diff -ru4NwbB libpng-1.6.0beta33/pngstruct.h libpng-1.7.0alpha02/pngstruct.h --- libpng-1.6.0beta33/pngstruct.h 2012-12-15 08:22:34.959263272 -0600 +++ libpng-1.7.0alpha02/pngstruct.h 2012-12-16 19:27:55.692936989 -0600 @@ -4,9 +4,9 @@ * Copyright (c) 1998-2012 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 1.6.0 [(PENDING RELEASE)] + * Last changed in libpng 1.6.0 [(PENDING RELEASE)] * * This code is released under the libpng license. * For conditions of distribution and use, see the disclaimer * and license in png.h @@ -47,12 +47,12 @@ /* zlib.h declares a magic type 'uInt' that limits the amount of data that zlib * can handle at once. This type need be no larger than 16 bits (so maximum of * 65535), this define allows us to discover how big it is, but limited by the - * maximuum for png_size_t. The value can be overriden in a library build - * (pngusr.h, or set it in CPPFLAGS) and it works to set it to a considerably - * lower value (e.g. 255 works). A lower value may help memory usage (slightly) - * and may even improve performance on some systems (and degrade it on others.) + * maximum for size_t. The value can be overridden in a library build (pngusr.h, + * or set it in CPPFLAGS) and it works to set it to a considerably lower value + * (e.g. 255 works). A lower value may help memory usage (slightly) and may + * even improve performance on some systems (and degrade it on others.) */ #ifndef ZLIB_IO_MAX # define ZLIB_IO_MAX ((uInt)-1) #endif @@ -136,348 +136,412 @@ #define PNG_COLORSPACE_FROM_cHRM 0x0010 #define PNG_COLORSPACE_FROM_sRGB 0x0020 #define PNG_COLORSPACE_ENDPOINTS_MATCH_sRGB 0x0040 #define PNG_COLORSPACE_MATCHES_sRGB 0x0080 /* exact match on profile */ +#define PNG_COLORSPACE_RGB_TO_GRAY_SET 0x0100 /* user specified coeffs */ #define PNG_COLORSPACE_INVALID 0x8000 #define PNG_COLORSPACE_CANCEL(flags) (0xffff ^ (flags)) #endif /* COLORSPACE || GAMMA */ struct png_struct_def { -#ifdef PNG_SETJMP_SUPPORTED - jmp_buf jmp_buf_local; /* New name in 1.6.0 for jmp_buf in png_struct */ - png_longjmp_ptr longjmp_fn;/* setjmp non-local goto function. */ - jmp_buf *jmp_buf_ptr; /* passed to longjmp_fn */ - size_t jmp_buf_size; /* size of the above, if allocated */ -#endif - png_error_ptr error_fn; /* function for printing errors and aborting */ -#ifdef PNG_WARNINGS_SUPPORTED - png_error_ptr warning_fn; /* function for printing warnings */ -#endif - png_voidp error_ptr; /* user supplied struct for error functions */ - png_rw_ptr write_data_fn; /* function for writing output data */ - png_rw_ptr read_data_fn; /* function for reading input data */ - png_voidp io_ptr; /* ptr to application struct for I/O functions */ - -#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED - png_user_transform_ptr read_user_transform_fn; /* user read transform */ -#endif - -#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED - png_user_transform_ptr write_user_transform_fn; /* user write transform */ -#endif - -/* These were added in libpng-1.0.2 */ -#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED -#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \ - defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) - png_voidp user_transform_ptr; /* user supplied struct for user transform */ - png_byte user_transform_depth; /* bit depth of user transformed pixels */ - png_byte user_transform_channels; /* channels in user transformed pixels */ -#endif -#endif - - png_uint_32 mode; /* tells us where we are in the PNG file */ - png_uint_32 flags; /* flags indicating various things to libpng */ - png_uint_32 transformations; /* which transformations to perform */ - - png_uint_32 zowner; /* ID (chunk type) of zstream owner, 0 if none */ - z_stream zstream; /* decompression structure */ - -#ifdef PNG_WRITE_SUPPORTED - png_compression_bufferp zbuffer_list; /* Created on demand during write */ - uInt zbuffer_size; /* size of the actual buffer */ - - int zlib_level; /* holds zlib compression level */ - int zlib_method; /* holds zlib compression method */ - int zlib_window_bits; /* holds zlib compression window bits */ - int zlib_mem_level; /* holds zlib compression memory level */ - int zlib_strategy; /* holds zlib compression strategy */ -#endif -/* Added at libpng 1.5.4 */ -#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED - int zlib_text_level; /* holds zlib compression level */ - int zlib_text_method; /* holds zlib compression method */ - int zlib_text_window_bits; /* holds zlib compression window bits */ - int zlib_text_mem_level; /* holds zlib compression memory level */ - int zlib_text_strategy; /* holds zlib compression strategy */ -#endif -/* End of material added at libpng 1.5.4 */ -/* Added at libpng 1.6.0 */ -#ifdef PNG_WRITE_SUPPORTED - int zlib_set_level; /* Actual values set into the zstream on write */ - int zlib_set_method; - int zlib_set_window_bits; - int zlib_set_mem_level; - int zlib_set_strategy; -#endif - + /* Rearranged in libpng 1.7 to attempt to lessen padding; in general + * (char), (short), (int) and pointer types are kept separate, however + * associated members under the control of the same #define are still + * together. + * + * First the frequently accessed fields. Many processors perform arithmetic + * in the address pipeline, but frequently the amount of addition or + * subtraction is limited. By putting these fields at the head of png_struct + * the hope is that such processors will generate code that is both smaller + * and faster. + */ + png_colorp palette; /* palette from the input file */ + size_t rowbytes; /* size of row in bytes */ + size_t info_rowbytes; /* cache of updated row bytes */ png_uint_32 width; /* width of image in pixels */ png_uint_32 height; /* height of image in pixels */ png_uint_32 num_rows; /* number of rows in current pass */ png_uint_32 usr_width; /* width of row at start of write */ - png_size_t rowbytes; /* size of row in bytes */ png_uint_32 iwidth; /* width of current interlaced row in pixels */ png_uint_32 row_number; /* current row in interlace pass */ png_uint_32 chunk_name; /* PNG_CHUNK() id of current chunk */ - png_bytep prev_row; /* buffer to save previous (unfiltered) row. - * This is a pointer into big_prev_row - */ - png_bytep row_buf; /* buffer to save current (unfiltered) row. - * This is a pointer into big_row_buf - */ -#ifdef PNG_WRITE_SUPPORTED - png_bytep sub_row; /* buffer to save "sub" row when filtering */ - png_bytep up_row; /* buffer to save "up" row when filtering */ - png_bytep avg_row; /* buffer to save "avg" row when filtering */ - png_bytep paeth_row; /* buffer to save "Paeth" row when filtering */ -#endif - png_size_t info_rowbytes; /* Added in 1.5.4: cache of updated row bytes */ - - png_uint_32 idat_size; /* current IDAT size for read */ png_uint_32 crc; /* current chunk CRC value */ - png_colorp palette; /* palette from the input file */ - png_uint_16 num_palette; /* number of color entries in palette */ + png_uint_32 mode; /* tells us where we are in the PNG file */ + png_uint_32 flags; /* flags indicating various things to libpng */ + png_uint_32 transformations;/* which transformations to perform */ + png_uint_32 zowner; /* ID (chunk type) of zstream owner, 0 if none */ + png_uint_32 free_me; /* items libpng is responsible for freeing */ -/* Added at libpng-1.5.10 */ + int maximum_pixel_depth; /* pixel depth used for the row buffers */ #ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED int num_palette_max; /* maximum palette index found in IDAT */ #endif + png_uint_16 num_palette; /* number of color entries in palette */ png_uint_16 num_trans; /* number of transparency values */ - png_byte compression; /* file compression type (always 0) */ + + /* Single byte values, typically used either to save space or to hold 1-byte + * values from the PNG chunk specifications. + */ + png_byte compression_type; /* file compression type (always 0) */ png_byte filter; /* file filter type (always 0) */ png_byte interlaced; /* PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */ png_byte pass; /* current interlace pass (0 - 6) */ png_byte do_filter; /* row filter flags (see PNG_FILTER_ below ) */ png_byte color_type; /* color type of file */ png_byte bit_depth; /* bit depth of file */ - png_byte usr_bit_depth; /* bit depth of users row: write only */ png_byte pixel_depth; /* number of bits per pixel */ png_byte channels; /* number of channels in file */ -#ifdef PNG_WRITE_SUPPORTED - png_byte usr_channels; /* channels at start of write: write only */ -#endif png_byte sig_bytes; /* magic bytes read/written from start of file */ - png_byte maximum_pixel_depth; - /* pixel depth used for the row buffers */ png_byte transformed_pixel_depth; /* pixel depth after read/write transforms */ -#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED) - png_uint_16 filler; /* filler bytes for pixel expansion */ + + /* ERROR HANDLING */ +#ifdef PNG_SETJMP_SUPPORTED + /* jmp_buf can have very high alignment requirements on some systems, so put + * it first. + */ + jmp_buf jmp_buf_local; + jmp_buf *jmp_buf_ptr; /* passed to longjmp_fn */ + png_longjmp_ptr longjmp_fn; /* setjmp non-local goto function. */ + size_t jmp_buf_size; /* size of *jmp_buf_ptr, if allocated */ #endif -#if defined(PNG_bKGD_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) ||\ - defined(PNG_READ_ALPHA_MODE_SUPPORTED) - png_byte background_gamma_type; - png_fixed_point background_gamma; - png_color_16 background; /* background color in screen gamma space */ -#ifdef PNG_READ_GAMMA_SUPPORTED - png_color_16 background_1; /* background normalized to gamma 1.0 */ + /* Error/warning callbacks */ + png_error_ptr error_fn; /* print an error message and abort */ +#ifdef PNG_WARNINGS_SUPPORTED + png_error_ptr warning_fn; /* print a warning and continue */ #endif -#endif /* PNG_bKGD_SUPPORTED */ + png_voidp error_ptr; /* user supplied data for the above */ -#ifdef PNG_WRITE_FLUSH_SUPPORTED - png_flush_ptr output_flush_fn; /* Function for flushing output */ - png_uint_32 flush_dist; /* how many rows apart to flush, 0 - no flush */ - png_uint_32 flush_rows; /* number of rows written since last flush */ + /* MEMORY ALLOCATION */ +#ifdef PNG_USER_MEM_SUPPORTED + png_malloc_ptr malloc_fn; /* allocate memory */ + png_free_ptr free_fn; /* free memory */ + png_voidp mem_ptr; /* user supplied data for the above */ #endif -#ifdef PNG_READ_GAMMA_SUPPORTED - int gamma_shift; /* number of "insignificant" bits in 16-bit gamma */ - png_fixed_point screen_gamma; /* screen gamma value (display_exponent) */ + /* IO and BASIC READ/WRITE SUPPORT */ + png_voidp io_ptr; /* user supplied data for IO callbacks */ - png_bytep gamma_table; /* gamma table for 8-bit depth files */ - png_uint_16pp gamma_16_table; /* gamma table for 16-bit depth files */ -#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \ - defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \ - defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) - png_bytep gamma_from_1; /* converts from 1.0 to screen */ - png_bytep gamma_to_1; /* converts from file to 1.0 */ - png_uint_16pp gamma_16_from_1; /* converts from 1.0 to screen */ - png_uint_16pp gamma_16_to_1; /* converts from file to 1.0 */ -#endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */ -#endif +#ifdef PNG_READ_SUPPORTED + png_rw_ptr read_data_fn; /* read some bytes (must succeed) */ + png_read_status_ptr read_row_fn; /* called after each row is decoded */ + png_bytep read_buffer; /* buffer for reading chunk data */ -#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_sBIT_SUPPORTED) - png_color_8 sig_bit; /* significant bits in each available channel */ -#endif + /* During read the following array is set up to point to the appropriate + * un-filter function, this allows per-image and per-processor optimization. + */ + void (*read_filter[PNG_FILTER_VALUE_LAST-1])(png_row_infop row_info, + png_bytep row, png_const_bytep prev_row); -#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED) - png_color_8 shift; /* shift for significant bit tranformation */ +#if (defined PNG_COLORSPACE_SUPPORTED || defined PNG_GAMMA_SUPPORTED) + /* The png_struct colorspace structure is only required on read - on write it + * is in (just) the info_struct. + */ + png_colorspace colorspace; #endif +#endif /* PNG_READ_SUPPORTED */ -#if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) \ - || defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) - png_bytep trans_alpha; /* alpha values for paletted files */ - png_color_16 trans_color; /* transparent color for non-paletted files */ +#ifdef PNG_SET_USER_LIMITS_SUPPORTED + png_uint_32 user_width_max; /* Maximum width on read */ + png_uint_32 user_height_max; /* Maximum height on read */ + /* Total memory that a single zTXt, sPLT, iTXt, iCCP, or unknown chunk + * can occupy when decompressed. 0 means unlimited. This field is a counter + * - it is decremented as memory is allocated. + */ + png_alloc_size_t user_chunk_malloc_max; +#endif +#ifdef PNG_USER_LIMITS_SUPPORTED + /* limit on total *number* of sPLT, text and unknown chunks that can be + * stored. 0 means unlimited. This field is a counter - it is decremented + * as chunks are encountered. + */ + png_uint_32 user_chunk_cache_max; #endif - png_read_status_ptr read_row_fn; /* called after each row is decoded */ - png_write_status_ptr write_row_fn; /* called after each row is encoded */ + /* The progressive reader gets passed data and calls application handling + * functions when appropriate. + */ #ifdef PNG_PROGRESSIVE_READ_SUPPORTED png_progressive_info_ptr info_fn; /* called after header data fully read */ - png_progressive_row_ptr row_fn; /* called after a prog. row is decoded */ + png_progressive_row_ptr row_fn; /* called after a row is decoded */ png_progressive_end_ptr end_fn; /* called after image is complete */ + + /* Progressive read control data */ png_bytep save_buffer_ptr; /* current location in save_buffer */ png_bytep save_buffer; /* buffer for previously read data */ png_bytep current_buffer_ptr; /* current location in current_buffer */ png_bytep current_buffer; /* buffer for recently used data */ + + size_t save_buffer_size; /* amount of data now in save_buffer */ + size_t save_buffer_max; /* total size of save_buffer */ + size_t buffer_size; /* total amount of available input data */ + size_t current_buffer_size; /* amount of data now in current_buffer */ + png_uint_32 push_length; /* size of current input chunk */ png_uint_32 skip_length; /* bytes to skip in input data */ - png_size_t save_buffer_size; /* amount of data now in save_buffer */ - png_size_t save_buffer_max; /* total size of save_buffer */ - png_size_t buffer_size; /* total amount of available input data */ - png_size_t current_buffer_size; /* amount of data now in current_buffer */ + int process_mode; /* what push library is currently doing */ int cur_palette; /* current push library palette index */ +#endif -#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */ - -#if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__) -/* For the Borland special 64K segment handler */ - png_bytepp offset_table_ptr; - png_bytep offset_table; - png_uint_16 offset_table_number; - png_uint_16 offset_table_count; - png_uint_16 offset_table_count_free; +#ifdef PNG_WRITE_SUPPORTED + png_rw_ptr write_data_fn;/* write some bytes (must succeed) */ + png_write_status_ptr write_row_fn; /* called after each row is encoded */ #endif -#ifdef PNG_READ_QUANTIZE_SUPPORTED - png_bytep palette_lookup; /* lookup table for quantizing */ - png_bytep quantize_index; /* index translation for palette files */ +#ifdef PNG_WRITE_FLUSH_SUPPORTED + png_flush_ptr output_flush_fn; /* Function for flushing output */ + png_uint_32 flush_dist; /* how many rows apart to flush, 0 - no flush */ + png_uint_32 flush_rows; /* number of rows written since last flush */ #endif #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED - png_byte heuristic_method; /* heuristic for row filter selection */ - png_byte num_prev_filters; /* number of weights for previous rows */ png_bytep prev_filters; /* filter type(s) of previous row(s) */ png_uint_16p filter_weights; /* weight(s) for previous line(s) */ png_uint_16p inv_filter_weights; /* 1/weight(s) for previous line(s) */ png_uint_16p filter_costs; /* relative filter calculation cost */ png_uint_16p inv_filter_costs; /* 1/relative filter calculation cost */ + png_byte heuristic_method; /* heuristic for row filter selection */ + png_byte num_prev_filters; /* number of weights for previous rows */ #endif -#if PNG_LIBPNG_VER < 10700 -/* To do: remove this from libpng-1.7 */ -#ifdef PNG_TIME_RFC1123_SUPPORTED - char time_buffer[29]; /* String to hold RFC 1123 time text */ +#ifdef PNG_WRITE_SUPPORTED + png_byte usr_bit_depth; /* bit depth of users row */ + png_byte usr_channels; /* channels at start of write */ #endif + +#ifdef PNG_IO_STATE_SUPPORTED + png_uint_32 io_state; /* tells the app read/write progress */ #endif -/* New members added in libpng-1.0.6 */ + /* ROW BUFFERS + * + * Members that hold pointers to the decompressed image rows. + */ + png_bytep row_buf; /* buffer for the current (unfiltered) row */ +#if (defined PNG_WRITE_FILTER_SUPPORTED) || (defined PNG_READ_SUPPORTED) + png_bytep prev_row; /* buffer to save the previous (unfiltered) row */ +#endif - png_uint_32 free_me; /* flags items libpng is responsible for freeing */ +#ifdef PNG_READ_SUPPORTED + /* The row_buf and prev_row pointers are misaligned so that the start of the + * row - after the filter byte - is aligned, the 'big_' pointers record the + * original allocated pointer. + */ + png_bytep big_row_buf; + png_bytep big_prev_row; + size_t big_row_buf_size; /* Actual size of both */ +#endif +#ifdef PNG_WRITE_SUPPORTED + /* This is somewhat excessive, there is no obvious reason on write to + * allocate a buffer for each possible filtered row, only for the one being + * tested and the current best. + * + * TODO: fix this + */ + png_bytep sub_row; /* buffer to save "sub" row when filtering */ + png_bytep up_row; /* buffer to save "up" row when filtering */ + png_bytep avg_row; /* buffer to save "avg" row when filtering */ + png_bytep paeth_row; /* buffer to save "Paeth" row when filtering */ +#endif + + /* UNKNOWN CHUNK HANDLING */ + /* TODO: this is excessively complicated, there are multiple ways of doing + * the same thing. It should be cleaned up, possibly by finding out which + * APIs applications really use. + */ #ifdef PNG_USER_CHUNKS_SUPPORTED + /* General purpose pointer for all user/unknown chunk handling; points to + * application supplied data for use in the read_user_chunk_fn callback + * (currently there is no write side support - the write side must use the + * set_unknown_chunks interface.) + */ png_voidp user_chunk_ptr; +#endif + #ifdef PNG_READ_USER_CHUNKS_SUPPORTED + /* This is called back from the unknown chunk handling */ png_user_chunk_ptr read_user_chunk_fn; /* user read chunk handler */ #endif +#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED + /* Temporary storage for unknown chunk that the library doesn't recognize, + * used while reading the chunk. + */ + png_unknown_chunk unknown_chunk; #endif #ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED - int unknown_default; /* As PNG_HANDLE_* */ - unsigned int num_chunk_list; /* Number of entries in the list */ png_bytep chunk_list; /* List of png_byte[5]; the textual chunk name * followed by a PNG_HANDLE_* byte */ + int unknown_default; /* As PNG_HANDLE_* */ + unsigned int num_chunk_list; /* Number of entries in the list */ #endif -/* New members added in libpng-1.0.3 */ -#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED - png_byte rgb_to_gray_status; - /* Added in libpng 1.5.5 to record setting of coefficients: */ - png_byte rgb_to_gray_coefficients_set; - /* These were changed from png_byte in libpng-1.0.6 */ - png_uint_16 rgb_to_gray_red_coeff; - png_uint_16 rgb_to_gray_green_coeff; - /* deleted in 1.5.5: rgb_to_gray_blue_coeff; */ + /* USER TRANSFORM SUPPORT */ +#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED + png_user_transform_ptr read_user_transform_fn; /* user read transform */ +#endif +#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED + png_user_transform_ptr write_user_transform_fn; /* user write transform */ +#endif +#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED + png_voidp user_transform_ptr; /* user supplied data for the above */ + png_byte user_transform_depth; /* bit depth of user transformed pixels */ + png_byte user_transform_channels; /* channels in user transformed pixels */ #endif -/* New member added in libpng-1.0.4 (renamed in 1.0.9) */ -#if defined(PNG_MNG_FEATURES_SUPPORTED) -/* Changed from png_byte to png_uint_32 at version 1.2.0 */ - png_uint_32 mng_features_permitted; + /* READ TRANSFORM SUPPORT + * + * Quite a lot of things can be done to the original image data on read, and + * most of these are configurable. The data required by the configurable + * read transforms should be stored here. The png_color_16 and png_color_8 + * structures have low alignment requirements and odd sizes, so may cause + * misalignment when present. Member alignment is as follows: + * + * png_color_16 png_uint_16 + * png_color_8 png_byte + */ + /* GAMMA/BACKGROUND/ALPHA-MODE/RGB-TO-GRAY/tRNS/sBIT + * + * These things are all interrelated because they need some or all of the + * gamma tables. Some attempt has been made below to order these members by + * size, so that as little padding as possible is required. + */ +#ifdef PNG_READ_GAMMA_SUPPORTED + png_bytep gamma_table; /* gamma table for 8-bit depth files */ + png_uint_16p gamma_16_table; /* gamma table for 16-bit depth files */ + +#if defined PNG_READ_BACKGROUND_SUPPORTED ||\ + defined PNG_READ_ALPHA_MODE_SUPPORTED ||\ + defined PNG_READ_RGB_TO_GRAY_SUPPORTED + png_bytep gamma_from_1; /* converts from 1.0 to screen */ + png_uint_16p gamma_to_1; /* converts from file to 1.0 */ + png_uint_16p gamma_16_from_1; /* converts from 1.0 to screen */ + png_uint_16p gamma_16_to_1; /* converts from file to 1.0 */ +#endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */ +#endif /* PNG_READ_GAMMA_SUPPORTED */ + +#if defined PNG_READ_tRNS_SUPPORTED || defined PNG_READ_BACKGROUND_SUPPORTED ||\ + defined PNG_READ_EXPAND_SUPPORTED + png_bytep trans_alpha; /* alpha values for paletted files */ #endif -/* New member added in libpng-1.0.9, ifdef'ed out in 1.0.12, enabled in 1.2.0 */ -#ifdef PNG_MNG_FEATURES_SUPPORTED - png_byte filter_type; + /* Integer values */ +#if defined PNG_READ_BACKGROUND_SUPPORTED ||\ + defined PNG_READ_ALPHA_MODE_SUPPORTED + png_fixed_point background_gamma; +#endif +#ifdef PNG_READ_GAMMA_SUPPORTED + png_fixed_point screen_gamma; /* screen gamma value (display_exponent) */ + int gamma_shift; /* number of "insignificant" bits in 16-bit gamma */ #endif -/* New members added in libpng-1.2.0 */ + /* png_color_16 */ +#if defined PNG_READ_BACKGROUND_SUPPORTED ||\ + defined PNG_READ_ALPHA_MODE_SUPPORTED + png_color_16 background; /* background color in screen gamma space */ + png_color_16 background_1; /* background normalized to gamma 1.0 */ +#endif +#if defined PNG_READ_tRNS_SUPPORTED || defined PNG_READ_BACKGROUND_SUPPORTED ||\ + defined PNG_READ_EXPAND_SUPPORTED + png_color_16 trans_color; /* transparent color for non-paletted files */ +#endif -/* New members added in libpng-1.0.2 but first enabled by default in 1.2.0 */ -#ifdef PNG_USER_MEM_SUPPORTED - png_voidp mem_ptr; /* user supplied struct for mem functions */ - png_malloc_ptr malloc_fn; /* function for allocating memory */ - png_free_ptr free_fn; /* function for freeing memory */ + /* png_uint_16 */ +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED + png_uint_16 rgb_to_gray_red_coeff; + png_uint_16 rgb_to_gray_green_coeff; + /* The blue coefficient is calculated from the above */ #endif -/* New member added in libpng-1.0.13 and 1.2.0 */ - png_bytep big_row_buf; /* buffer to save current (unfiltered) row */ + /* png_color_8 */ +#if defined PNG_READ_GAMMA_SUPPORTED || defined PNG_READ_sBIT_SUPPORTED + png_color_8 sig_bit; /* significant bits in each available channel */ +#endif -#ifdef PNG_READ_QUANTIZE_SUPPORTED -/* The following three members were added at version 1.0.14 and 1.2.4 */ - png_bytep quantize_sort; /* working sort array */ - png_bytep index_to_palette; /* where the original index currently is - in the palette */ - png_bytep palette_to_index; /* which original index points to this - palette color */ + /* png_byte */ +#if defined PNG_READ_BACKGROUND_SUPPORTED ||\ + defined PNG_READ_ALPHA_MODE_SUPPORTED + png_byte background_gamma_type; +#endif +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED + png_byte rgb_to_gray_status; #endif -/* New members added in libpng-1.0.16 and 1.2.6 */ - png_byte compression_type; + /* SHIFT - both READ_SHIFT and WRITE_SHIFT */ +#if defined PNG_READ_SHIFT_SUPPORTED || defined PNG_WRITE_SHIFT_SUPPORTED + png_color_8 shift; /* shift for significant bit tranformation */ +#endif -#ifdef PNG_USER_LIMITS_SUPPORTED - png_uint_32 user_width_max; - png_uint_32 user_height_max; + /* FILLER SUPPORT (pixel expansion or read, contraction on write) */ +#if defined PNG_READ_FILLER_SUPPORTED || defined PNG_WRITE_FILLER_SUPPORTED + png_uint_16 filler; /* filler bytes for pixel expansion */ +#endif - /* Added in libpng-1.4.0: Total number of sPLT, text, and unknown - * chunks that can be stored (0 means unlimited). + /* QUANTIZE (convert to color-mapped) */ +#ifdef PNG_READ_QUANTIZE_SUPPORTED + png_bytep palette_lookup; /* lookup table for quantizing */ + png_bytep quantize_index; /* index translation for palette files */ + png_bytep quantize_sort; /* working sort array */ + png_bytep index_to_palette; /* where the original index currently is in the + * palette */ - png_uint_32 user_chunk_cache_max; - - /* Total memory that a zTXt, sPLT, iTXt, iCCP, or unknown chunk - * can occupy when decompressed. 0 means unlimited. + png_bytep palette_to_index; /* which original index points to this palette + * color */ - png_alloc_size_t user_chunk_malloc_max; #endif -/* New member added in libpng-1.0.25 and 1.2.17 */ -#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED - /* Temporary storage for unknown chunk that the library doesn't recognize, - * used while reading the chunk. - */ - png_unknown_chunk unknown_chunk; + /* MNG SUPPORT */ +#ifdef PNG_MNG_FEATURES_SUPPORTED + png_uint_32 mng_features_permitted; + png_byte filter_type; #endif -/* New member added in libpng-1.2.26 */ - png_size_t old_big_row_buf_size; + /* COMPRESSION AND DECOMPRESSION SUPPORT. + * + * zlib expects a 'zstream' as the fundamental control structure, it allows + * all the parameters to be passed as one pointer. + */ + z_stream zstream; /* decompression structure */ #ifdef PNG_READ_SUPPORTED -/* New member added in libpng-1.2.30 */ - png_bytep read_buffer; /* buffer for reading chunk data */ + /* These, and IDAT_read_size below, control how much input and output (at + * most) is available to zlib. + */ + png_uint_32 idat_size; /* current IDAT size for read */ png_alloc_size_t read_buffer_size; /* current size of the buffer */ #endif -#ifdef PNG_SEQUENTIAL_READ_SUPPORTED - uInt IDAT_read_size; /* limit on read buffer size for IDAT */ -#endif -#ifdef PNG_IO_STATE_SUPPORTED -/* New member added in libpng-1.4.0 */ - png_uint_32 io_state; +#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED + int zlib_text_level; /* holds zlib compression level */ + int zlib_text_method; /* holds zlib compression method */ + int zlib_text_window_bits; /* holds zlib compression window bits */ + int zlib_text_mem_level; /* holds zlib compression memory level */ + int zlib_text_strategy; /* holds zlib compression strategy */ #endif -/* New member added in libpng-1.5.6 */ - png_bytep big_prev_row; +#ifdef PNG_WRITE_SUPPORTED + int zlib_level; /* holds zlib compression level */ + int zlib_method; /* holds zlib compression method */ + int zlib_window_bits; /* holds zlib compression window bits */ + int zlib_mem_level; /* holds zlib compression memory level */ + int zlib_strategy; /* holds zlib compression strategy */ - void (*read_filter[PNG_FILTER_VALUE_LAST-1])(png_row_infop row_info, - png_bytep row, png_const_bytep prev_row); + int zlib_set_level; /* Actual values set into the zstream on write */ + int zlib_set_method; + int zlib_set_window_bits; + int zlib_set_mem_level; + int zlib_set_strategy; -#ifdef PNG_READ_SUPPORTED -#if defined PNG_COLORSPACE_SUPPORTED || defined PNG_GAMMA_SUPPORTED - png_colorspace colorspace; + png_compression_bufferp zbuffer_list; /* Created on demand during write */ + uInt zbuffer_size; /* size of the actual zlib buffer */ #endif + +#ifdef PNG_SEQUENTIAL_READ_SUPPORTED + uInt IDAT_read_size; /* limit on read buffer size for IDAT */ #endif }; #endif /* PNGSTRUCT_H */ diff -ru4NwbB libpng-1.6.0beta33/pngtest.c libpng-1.7.0alpha02/pngtest.c --- libpng-1.6.0beta33/pngtest.c 2012-12-15 08:22:35.102408430 -0600 +++ libpng-1.7.0alpha02/pngtest.c 2012-12-16 19:27:55.846625165 -0600 @@ -1,8 +1,8 @@ /* pngtest.c - a simple test program to test libpng * - * Last changed in libpng 1.6.0 [(PENDING RELEASE)] + * Last changed in libpng 1.7.0 [(PENDING RELEASE)] * Copyright (c) 1998-2012 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-1.6.0beta33/pngtrans.c libpng-1.7.0alpha02/pngtrans.c --- libpng-1.6.0beta33/pngtrans.c 2012-12-15 08:22:35.110156186 -0600 +++ libpng-1.7.0alpha02/pngtrans.c 2012-12-16 19:27:55.854334116 -0600 @@ -1,8 +1,8 @@ /* pngtrans.c - transforms the data in a row (used by both readers and writers) * - * Last changed in libpng 1.6.0 [(PENDING RELEASE)] + * Last changed in libpng 1.7.0 [(PENDING RELEASE)] * Copyright (c) 1998-2012 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.) * @@ -56,9 +56,11 @@ if (png_ptr->bit_depth < 8) { png_ptr->transformations |= PNG_PACK; +# ifdef PNG_WRITE_SUPPORTED png_ptr->usr_bit_depth = 8; +# endif } } #endif diff -ru4NwbB libpng-1.6.0beta33/pngwio.c libpng-1.7.0alpha02/pngwio.c --- libpng-1.6.0beta33/pngwio.c 2012-12-15 08:22:35.115737137 -0600 +++ libpng-1.7.0alpha02/pngwio.c 2012-12-16 19:27:55.859922713 -0600 @@ -1,8 +1,8 @@ /* pngwio.c - functions for data output * - * Last changed in libpng 1.6.0 [(PENDING RELEASE)] + * Last changed in libpng 1.7.0 [(PENDING RELEASE)] * Copyright (c) 1998-2012 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.) * @@ -150,8 +150,9 @@ png_ptr->output_flush_fn = output_flush_fn; # endif #endif /* PNG_WRITE_FLUSH_SUPPORTED */ +#ifdef PNG_READ_SUPPORTED /* It is an error to read while writing a png file */ if (png_ptr->read_data_fn != NULL) { png_ptr->read_data_fn = NULL; @@ -159,6 +160,7 @@ png_warning(png_ptr, "Can't set both read_data_fn and write_data_fn in the" " same structure"); } +#endif } #endif /* PNG_WRITE_SUPPORTED */ diff -ru4NwbB libpng-1.6.0beta33/pngwrite.c libpng-1.7.0alpha02/pngwrite.c --- libpng-1.6.0beta33/pngwrite.c 2012-12-15 08:22:35.126743178 -0600 +++ libpng-1.7.0alpha02/pngwrite.c 2012-12-16 19:27:55.870993421 -0600 @@ -1,8 +1,8 @@ /* pngwrite.c - general routines to write a PNG file * - * Last changed in libpng 1.6.0 [(PENDING RELEASE)] + * Last changed in libpng 1.7.0 [(PENDING RELEASE)] * Copyright (c) 1998-2012 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.) * @@ -215,10 +215,15 @@ /* Invert the alpha channel (in tRNS) */ if ((png_ptr->transformations & PNG_INVERT_ALPHA) && info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) { - int j; - for (j = 0; j<(int)info_ptr->num_trans; j++) + int j, jend; + + jend = info_ptr->num_trans; + if (jend > PNG_MAX_PALETTE_LENGTH) + jend = PNG_MAX_PALETTE_LENGTH; + + for (j = 0; jtrans_alpha[j] = (png_byte)(255 - info_ptr->trans_alpha[j]); } #endif @@ -926,121 +931,101 @@ #ifdef PNG_MNG_FEATURES_SUPPORTED if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) && (method == PNG_INTRAPIXEL_DIFFERENCING)) method = PNG_FILTER_TYPE_BASE; - #endif - if (method == PNG_FILTER_TYPE_BASE) - { - switch (filters & (PNG_ALL_FILTERS | 0x07)) - { -#ifdef PNG_WRITE_FILTER_SUPPORTED - case 5: - case 6: - case 7: png_app_error(png_ptr, "Unknown row filter for method 0"); - /* FALL THROUGH */ -#endif /* PNG_WRITE_FILTER_SUPPORTED */ - case PNG_FILTER_VALUE_NONE: - png_ptr->do_filter = PNG_FILTER_NONE; break; + /* The only supported method, except for the check above, is + * PNG_FILTER_TYPE_BASE. The code below does not use 'method' other than + * for the check, so just keep going if png_app_error returns. + */ + if (method != PNG_FILTER_TYPE_BASE) + png_app_error(png_ptr, "Unknown custom filter method"); + + /* If filter writing is not supported the 'filters' value must be zero, + * otherwise the value must be a single, valid, filter value or a set of the + * mask values. The defines in png.h are such that the filter masks used in + * this API and internally are 1<<(3+value), value is in the range 0..4, so + * this fits in a byte. + */ #ifdef PNG_WRITE_FILTER_SUPPORTED - case PNG_FILTER_VALUE_SUB: - png_ptr->do_filter = PNG_FILTER_SUB; break; - - case PNG_FILTER_VALUE_UP: - png_ptr->do_filter = PNG_FILTER_UP; break; + /* Notice that PNG_NO_FILTERS is 0 and passes this test; this is OK + * because filters then gets set to PNG_FILTER_NONE, as is required. + */ + if (filters < PNG_FILTER_VALUE_LAST) + filters = 0x08 << filters; - case PNG_FILTER_VALUE_AVG: - png_ptr->do_filter = PNG_FILTER_AVG; break; + else if ((filters & ~PNG_ALL_FILTERS) != 0) + { + png_app_error(png_ptr, "png_set_filter: invalid filters mask/value"); - case PNG_FILTER_VALUE_PAETH: - png_ptr->do_filter = PNG_FILTER_PAETH; break; + /* For compatibility with the previous behavior assume a mask value was + * passed and ignore the non-mask bits. + */ + filters &= PNG_ALL_FILTERS; - default: - png_ptr->do_filter = (png_byte)filters; break; -#else - default: - png_app_error(png_ptr, "Unknown row filter for method 0"); -#endif /* PNG_WRITE_FILTER_SUPPORTED */ + /* For a possibly foolish consistency (it shouldn't matter) set + * PNG_FILTER_NONE rather than 0. + */ + if (filters == 0) + filters = PNG_FILTER_NONE; } +# else + /* PNG_FILTER_VALUE_NONE and PNG_NO_FILTERS are both 0. */ + if (filters != 0 && filters != PNG_FILTER_NONE) + png_app_error(png_ptr, "png_set_filter: no filters supported"); + + filters = PNG_FILTER_NONE; +# endif +# ifdef PNG_WRITE_FILTER_SUPPORTED /* If we have allocated the row_buf, this means we have already started * with the image and we should have allocated all of the filter buffers * that have been selected. If prev_row isn't already allocated, then * it is too late to start using the filters that need it, since we * will be missing the data in the previous row. If an application * wants to start and stop using particular filters during compression, * it should start out with all of the filters, and then add and * remove them after the start of compression. + * + * NOTE: this is a nasty constraint on the code, because it means that the + * prev_row buffer must be maintained even if there are currently no + * 'prev_row' requiring filters active. */ if (png_ptr->row_buf != NULL) { -#ifdef PNG_WRITE_FILTER_SUPPORTED - if ((png_ptr->do_filter & PNG_FILTER_SUB) && png_ptr->sub_row == NULL) - { - png_ptr->sub_row = (png_bytep)png_malloc(png_ptr, - (png_ptr->rowbytes + 1)); - png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB; - } - - if ((png_ptr->do_filter & PNG_FILTER_UP) && png_ptr->up_row == NULL) - { - if (png_ptr->prev_row == NULL) - { - png_warning(png_ptr, "Can't add Up filter after starting"); - png_ptr->do_filter = (png_byte)(png_ptr->do_filter & - ~PNG_FILTER_UP); - } + /* Repeat the checks in png_write_start_row; 1 pixel high or wide + * images cannot benefit from certain filters. If this isn't done here + * the check below will fire on 1 pixel high images. + */ + if (png_ptr->height == 1) + filters &= ~(PNG_FILTER_UP|PNG_FILTER_AVG|PNG_FILTER_PAETH); - else - { - png_ptr->up_row = (png_bytep)png_malloc(png_ptr, - (png_ptr->rowbytes + 1)); - png_ptr->up_row[0] = PNG_FILTER_VALUE_UP; - } - } + if (png_ptr->width == 1) + filters &= ~(PNG_FILTER_SUB|PNG_FILTER_AVG|PNG_FILTER_PAETH); - if ((png_ptr->do_filter & PNG_FILTER_AVG) && png_ptr->avg_row == NULL) - { - if (png_ptr->prev_row == NULL) + if ((filters & (PNG_FILTER_UP|PNG_FILTER_AVG|PNG_FILTER_PAETH)) != 0 + && png_ptr->prev_row == NULL) { - png_warning(png_ptr, "Can't add Average filter after starting"); - png_ptr->do_filter = (png_byte)(png_ptr->do_filter & - ~PNG_FILTER_AVG); - } - - else - { - png_ptr->avg_row = (png_bytep)png_malloc(png_ptr, - (png_ptr->rowbytes + 1)); - png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG; - } - } - - if ((png_ptr->do_filter & PNG_FILTER_PAETH) && - png_ptr->paeth_row == NULL) - { - if (png_ptr->prev_row == NULL) - { - png_warning(png_ptr, "Can't add Paeth filter after starting"); - png_ptr->do_filter &= (png_byte)(~PNG_FILTER_PAETH); + /* This is the error case, however it is benign - the previous row + * is not available so the filter can't be used. Just warn here. + */ + png_app_warning(png_ptr, + "png_set_filter: UP/AVG/PAETH cannot be added after start"); + filters &= ~(PNG_FILTER_UP|PNG_FILTER_AVG|PNG_FILTER_PAETH); } - else - { - png_ptr->paeth_row = (png_bytep)png_malloc(png_ptr, - (png_ptr->rowbytes + 1)); - png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH; - } + /* Allocate any required buffers that have not already been allocated. + */ + png_write_alloc_filter_row_buffers(png_ptr, filters); } - - if (png_ptr->do_filter == PNG_NO_FILTERS) #endif /* PNG_WRITE_FILTER_SUPPORTED */ - png_ptr->do_filter = PNG_FILTER_NONE; - } - } - else - png_error(png_ptr, "Unknown custom filter method"); + + /* Finally store the value. + * TODO: this field could probably be removed if neither READ nor + * WRITE_FILTER are supported. + */ + png_ptr->do_filter = (png_byte)filters; /* SAFE: checked above */ } /* This allows us to influence the way in which libpng chooses the "best" * filter for the current scanline. While the "minimum-sum-of-absolute- diff -ru4NwbB libpng-1.6.0beta33/pngwutil.c libpng-1.7.0alpha02/pngwutil.c --- libpng-1.6.0beta33/pngwutil.c 2012-12-15 08:22:35.146220665 -0600 +++ libpng-1.7.0alpha02/pngwutil.c 2012-12-16 19:27:55.890815066 -0600 @@ -1,8 +1,8 @@ /* pngwutil.c - utilities to write a PNG file * - * Last changed in libpng 1.6.0 [(PENDING RELEASE)] + * Last changed in libpng 1.7.0 [(PENDING RELEASE)] * Copyright (c) 1998-2012 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.) * @@ -1424,11 +1424,12 @@ png_debug(1, "in png_write_tRNS"); if (color_type == PNG_COLOR_TYPE_PALETTE) { - if (num_trans <= 0 || num_trans > (int)png_ptr->num_palette) + if (num_trans <= 0 || num_trans > png_ptr->num_palette) { - png_app_warning(png_ptr, + /* This is an error which can only be reliably detected late. */ + png_app_error(png_ptr, "Invalid number of transparent colors specified"); return; } @@ -1441,9 +1442,10 @@ { /* One 16 bit value */ if (tran->gray >= (1 << png_ptr->bit_depth)) { - png_app_warning(png_ptr, + /* This can no longer happen because it is checked in png_set_tRNS */ + png_app_error(png_ptr, "Ignoring attempt to write tRNS chunk out-of-range for bit_depth"); return; } @@ -1463,9 +1465,10 @@ #else if (buf[0] | buf[2] | buf[4]) #endif { - png_app_warning(png_ptr, + /* Also checked in png_set_tRNS */ + png_app_error(png_ptr, "Ignoring attempt to write 16-bit tRNS chunk when bit_depth is 8"); return; } @@ -1473,9 +1476,10 @@ } else { - png_app_warning(png_ptr, "Can't write tRNS with an alpha channel"); + /* Checked in png_set_tRNS */ + png_app_error(png_ptr, "Can't write tRNS with an alpha channel"); } } #endif @@ -1930,8 +1934,49 @@ png_write_complete_chunk(png_ptr, png_tIME, buf, (png_size_t)7); } #endif +#ifdef PNG_WRITE_FILTER_SUPPORTED +void /* PRIVATE */ +png_write_alloc_filter_row_buffers(png_structrp png_ptr, int filters) + /* Allocate row buffers for any filters that need them, this is also called + * from png_set_filter if the filters are changed during write to ensure that + * the required buffers exist. png_set_filter ensures that up/avg/paeth are + * only set if png_ptr->prev_row is allocated. + */ +{ + /* The buffer size is determined just by the output row size, not any + * processing requirements. + */ + png_alloc_size_t buf_size = png_ptr->rowbytes + 1; + + if ((filters & PNG_FILTER_SUB) != 0 && png_ptr->sub_row == NULL) + { + png_ptr->sub_row = png_voidcast(png_bytep, png_malloc(png_ptr, buf_size)); + png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB; + } + + if ((filters & PNG_FILTER_UP) != 0 && png_ptr->up_row == NULL) + { + png_ptr->up_row = png_voidcast(png_bytep, png_malloc(png_ptr, buf_size)); + png_ptr->up_row[0] = PNG_FILTER_VALUE_UP; + } + + if ((filters & PNG_FILTER_AVG) != 0 && png_ptr->avg_row == NULL) + { + png_ptr->avg_row = png_voidcast(png_bytep, png_malloc(png_ptr, buf_size)); + png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG; + } + + if ((filters & PNG_FILTER_PAETH) != 0 && png_ptr->paeth_row == NULL) + { + png_ptr->paeth_row = png_voidcast(png_bytep, png_malloc(png_ptr, + buf_size)); + png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH; + } +} +#endif /* PNG_WRITE_FILTER_SUPPORTED */ + /* Initializes the row writing capability of libpng */ void /* PRIVATE */ png_write_start_row(png_structrp png_ptr) { @@ -1950,64 +1995,56 @@ /* Offset to next interlace block in the y direction */ static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; #endif +#ifdef PNG_WRITE_FILTER_SUPPORTED + int filters; +#endif + png_alloc_size_t buf_size; int usr_pixel_depth; png_debug(1, "in png_write_start_row"); + if (png_ptr == NULL) + return; + usr_pixel_depth = png_ptr->usr_channels * png_ptr->usr_bit_depth; buf_size = PNG_ROWBYTES(usr_pixel_depth, png_ptr->width) + 1; /* 1.5.6: added to allow checking in the row write code. */ png_ptr->transformed_pixel_depth = png_ptr->pixel_depth; png_ptr->maximum_pixel_depth = (png_byte)usr_pixel_depth; /* Set up row buffer */ - png_ptr->row_buf = (png_bytep)png_malloc(png_ptr, buf_size); + png_ptr->row_buf = png_voidcast(png_bytep, png_malloc(png_ptr, buf_size)); png_ptr->row_buf[0] = PNG_FILTER_VALUE_NONE; #ifdef PNG_WRITE_FILTER_SUPPORTED - /* Set up filtering buffer, if using this filter */ - if (png_ptr->do_filter & PNG_FILTER_SUB) - { - png_ptr->sub_row = (png_bytep)png_malloc(png_ptr, png_ptr->rowbytes + 1); + filters = png_ptr->do_filter; - png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB; - } - - /* We only need to keep the previous row if we are using one of these. */ - if (png_ptr->do_filter & (PNG_FILTER_AVG | PNG_FILTER_UP | PNG_FILTER_PAETH)) - { - /* Set up previous row buffer */ - png_ptr->prev_row = (png_bytep)png_calloc(png_ptr, buf_size); - - if (png_ptr->do_filter & PNG_FILTER_UP) - { - png_ptr->up_row = (png_bytep)png_malloc(png_ptr, - png_ptr->rowbytes + 1); + if (png_ptr->height == 1) + filters &= ~(PNG_FILTER_UP|PNG_FILTER_AVG|PNG_FILTER_PAETH); - png_ptr->up_row[0] = PNG_FILTER_VALUE_UP; - } + if (png_ptr->width == 1) + filters &= ~(PNG_FILTER_SUB|PNG_FILTER_AVG|PNG_FILTER_PAETH); - if (png_ptr->do_filter & PNG_FILTER_AVG) - { - png_ptr->avg_row = (png_bytep)png_malloc(png_ptr, - png_ptr->rowbytes + 1); + if (filters == 0) + filters = PNG_FILTER_NONE; - png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG; - } + /* We only need to keep the previous row if we are using one of the following + * filters. + */ + if (filters & (PNG_FILTER_AVG | PNG_FILTER_UP | PNG_FILTER_PAETH)) + png_ptr->prev_row = png_voidcast(png_bytep, png_calloc(png_ptr, + buf_size)); - if (png_ptr->do_filter & PNG_FILTER_PAETH) - { - png_ptr->paeth_row = (png_bytep)png_malloc(png_ptr, - png_ptr->rowbytes + 1); + png_write_alloc_filter_row_buffers(png_ptr, filters); - png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH; - } - } + png_ptr->do_filter = (png_byte)filters; /* in case it was changed above */ +#else + png_ptr->do_filter = PNG_FILTER_NONE; #endif /* PNG_WRITE_FILTER_SUPPORTED */ #ifdef PNG_WRITE_INTERLACING_SUPPORTED /* If interlaced, we need to set up width and height of pass */ diff -ru4NwbB libpng-1.6.0beta33/projects/vstudio/libpng/libpng.vcxproj libpng-1.7.0alpha02/projects/vstudio/libpng/libpng.vcxproj --- libpng-1.6.0beta33/projects/vstudio/libpng/libpng.vcxproj 2012-12-15 08:22:37.650759334 -0600 +++ libpng-1.7.0alpha02/projects/vstudio/libpng/libpng.vcxproj 2012-12-16 19:27:58.502394592 -0600 @@ -62,25 +62,25 @@ false - $(ProjectName)16 + $(ProjectName)17 false - $(ProjectName)16 + $(ProjectName)17 false - $(ProjectName)16 + $(ProjectName)17 false - $(ProjectName)16 + $(ProjectName)17 Use @@ -106,9 +106,9 @@ Windows true zlib.lib - 16 + 17 $(OutDir) @@ -163,9 +163,9 @@ true true true zlib.lib - 16 + 17 $(OutDir) diff -ru4NwbB libpng-1.6.0beta33/projects/vstudio/pngtest/pngtest.vcxproj libpng-1.7.0alpha02/projects/vstudio/pngtest/pngtest.vcxproj --- libpng-1.6.0beta33/projects/vstudio/pngtest/pngtest.vcxproj 2012-12-15 08:22:37.661580689 -0600 +++ libpng-1.7.0alpha02/projects/vstudio/pngtest/pngtest.vcxproj 2012-12-16 19:27:58.513382324 -0600 @@ -95,9 +95,9 @@ Console true - libpng16.lib + libpng17.lib $(OutDir) Executing PNG test program @@ -128,9 +128,9 @@ Console true - libpng16.lib;zlib.lib + libpng17.lib;zlib.lib $(OutDir) Executing PNG test program @@ -163,9 +163,9 @@ true true true UseLinkTimeCodeGeneration - libpng16.lib + libpng17.lib $(OutDir) Executing PNG test program @@ -198,9 +198,9 @@ Console true true true - libpng16.lib;zlib.lib + libpng17.lib;zlib.lib UseLinkTimeCodeGeneration $(OutDir) diff -ru4NwbB libpng-1.6.0beta33/projects/vstudio/pngunknown/pngunknown.vcxproj libpng-1.7.0alpha02/projects/vstudio/pngunknown/pngunknown.vcxproj --- libpng-1.6.0beta33/projects/vstudio/pngunknown/pngunknown.vcxproj 2012-12-15 08:22:37.672454427 -0600 +++ libpng-1.7.0alpha02/projects/vstudio/pngunknown/pngunknown.vcxproj 2012-12-16 19:27:58.524339987 -0600 @@ -95,9 +95,9 @@ Console true - libpng16.lib;zlib.lib + libpng17.lib;zlib.lib $(OutDir) Executing PNG validation program @@ -128,9 +128,9 @@ Console true - libpng16.lib;zlib.lib + libpng17.lib;zlib.lib $(OutDir) Executing PNG validation program @@ -162,9 +162,9 @@ Console true true true - libpng16.lib;zlib.lib + libpng17.lib;zlib.lib $(OutDir) UseLinkTimeCodeGeneration @@ -198,9 +198,9 @@ Console true true true - libpng16.lib;zlib.lib + libpng17.lib;zlib.lib $(OutDir) UseLinkTimeCodeGeneration diff -ru4NwbB libpng-1.6.0beta33/projects/vstudio/pngvalid/pngvalid.vcxproj libpng-1.7.0alpha02/projects/vstudio/pngvalid/pngvalid.vcxproj --- libpng-1.6.0beta33/projects/vstudio/pngvalid/pngvalid.vcxproj 2012-12-15 08:22:37.682948223 -0600 +++ libpng-1.7.0alpha02/projects/vstudio/pngvalid/pngvalid.vcxproj 2012-12-16 19:27:58.535227870 -0600 @@ -95,9 +95,9 @@ Console true - libpng16.lib;zlib.lib + libpng17.lib;zlib.lib $(OutDir) Executing PNG validation program @@ -128,9 +128,9 @@ Console true - libpng16.lib;zlib.lib + libpng17.lib;zlib.lib $(OutDir) Executing PNG validation program @@ -162,9 +162,9 @@ Console true true true - libpng16.lib;zlib.lib + libpng17.lib;zlib.lib $(OutDir) UseLinkTimeCodeGeneration @@ -198,9 +198,9 @@ Console true true true - libpng16.lib;zlib.lib + libpng17.lib;zlib.lib $(OutDir) UseLinkTimeCodeGeneration diff -ru4NwbB libpng-1.6.0beta33/projects/vstudio/readme.txt libpng-1.7.0alpha02/projects/vstudio/readme.txt --- libpng-1.6.0beta33/projects/vstudio/readme.txt 2012-12-15 08:22:37.631136652 -0600 +++ libpng-1.7.0alpha02/projects/vstudio/readme.txt 2012-12-16 19:27:58.482396692 -0600 @@ -39,9 +39,9 @@ problems. If you don't use the Visual Studio defaults your application must still be built with the default runtime option (/MD). If, for some reason, it is not then your -application will crash inside libpng16.dll as soon as libpng tries to read +application will crash inside libpng17.dll as soon as libpng tries to read from a file handle you pass in. If you do not want to use the DLL, for example for a very small application, the 'release library' configuration may be more appropriate. This is built diff -ru4NwbB libpng-1.6.0beta33/scripts/def.dfn libpng-1.7.0alpha02/scripts/def.dfn --- libpng-1.6.0beta33/scripts/def.dfn 2011-12-21 08:49:02.000000000 -0600 +++ libpng-1.7.0alpha02/scripts/def.dfn 2012-12-16 19:27:57.902715004 -0600 @@ -24,9 +24,9 @@ S-OS2 DESCRIPTION "PNG image compression library"-E S-OS2 CODE PRELOAD MOVEABLE DISCARDABLE-E S--E S-EXPORTS-E -S-;Version 1.5.0beta58-E +S-;Version 1.7.0alpha02-E /* 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, diff -ru4NwbB libpng-1.6.0beta33/scripts/pnglibconf.dfa libpng-1.7.0alpha02/scripts/pnglibconf.dfa --- libpng-1.6.0beta33/scripts/pnglibconf.dfa 2012-12-15 08:22:37.557499978 -0600 +++ libpng-1.7.0alpha02/scripts/pnglibconf.dfa 2012-12-16 19:27:58.407483362 -0600 @@ -275,50 +275,42 @@ # Added at libpng-1.4.0 option IO_STATE -# This is only for PowerPC big-endian and 680x0 systems -# some testing, not enabled by default. -# NO LONGER USED - -#option READ_BIG_ENDIAN disabled - -# Allow users to control limits on what the READ code will -# read: - -# Added at libpng-1.2.43; adds limit fields to png_struct, -# allows some usages of these fields - -option USER_LIMITS - -# Added at libpng-1.2.6; adds setting APIs, allows additional -# usage of this field (UTSL) - -option SET_USER_LIMITS requires USER_LIMITS - -# Feature added at libpng-1.4.0, this flag added at 1.4.1 -option SET_USER_LIMITS enables SET_CHUNK_CACHE_LIMIT -# Feature added at libpng-1.4.1, this flag added at 1.4.1 +# Libpng limits: limit the size of images and data on read. +# +# If this option is disabled all the limit checking code will be disabled: -option SET_USER_LIMITS enables SET_CHUNK_MALLOC_LIMIT +option USER_LIMITS requires READ -# Libpng limits. -# -# If these settings are *not* set libpng will not limit the size of +# If the following settings are *not* set libpng will not limit the size of # images or the size of data in ancilliary chunks. This does lead to -# security issues if PNG files come from untrusted sources. +# security issues if PNG files come from untrusted sources. Settings have the +# following interpretations: +# +# USER_WIDTH_MAX: maximum width of an image that will be read +# USER_HEIGHT_MAX: maximum height +# USER_CHUNK_MALLOC_MAX: maximum in-memory (decompressed) size of a single chunk +# USER_CHUNK_CACHE_MAX: maximum number of chunks to be cached +# +# Only chunks that are variable in number are counted towards the +# USER_CHUNK_CACHE_MAX limit setting USER_WIDTH_MAX setting USER_HEIGHT_MAX -setting USER_CHUNK_CACHE_MAX setting USER_CHUNK_MALLOC_MAX +setting USER_CHUNK_CACHE_MAX # To default all these settings to values that are large but probably # safe turn the SAFE_LIMITS option on; this will cause the value in # pngpriv.h to be used. Individual values can also be set, simply set # them in pngusr.dfa with '@#define PNG_setting value' lines. option SAFE_LIMITS enables USER_LIMITS disabled = SAFE_LIMITS SAFE_LIMITS +# If this option is enabled APIs to set the above limits at run time are added; +# without these the hardwired (compile time) limits will be used. +option SET_USER_LIMITS requires USER_LIMITS + # All of the following options relate to code capabilities for # processing image data before creating a PNG or after reading one. # You can remove these capabilities safely and still be PNG # conformant, however the library that results is still non-standard. diff -ru4NwbB libpng-1.6.0beta33/scripts/symbols.def libpng-1.7.0alpha02/scripts/symbols.def --- libpng-1.6.0beta33/scripts/symbols.def 2012-12-15 08:22:37.579864777 -0600 +++ libpng-1.7.0alpha02/scripts/symbols.def 2012-12-16 19:27:58.430350557 -0600 @@ -14,22 +14,19 @@ png_get_compression_buffer_size @6 png_set_compression_buffer_size @7 png_set_longjmp_fn @8 png_longjmp @9 - png_reset_zstream @10 png_create_read_struct_2 @11 png_create_write_struct_2 @12 png_write_sig @13 png_write_chunk @14 png_write_chunk_start @15 png_write_chunk_data @16 png_write_chunk_end @17 png_create_info_struct @18 - png_info_init_3 @19 png_write_info_before_PLTE @20 png_write_info @21 png_read_info @22 - png_convert_to_rfc1123 @23 png_convert_from_struct_tm @24 png_convert_from_time_t @25 png_set_expand @26 png_set_expand_gray_1_2_4_to_8 @27 @@ -103,11 +100,8 @@ png_calloc @95 png_malloc_warn @96 png_free @97 png_free_data @98 - png_data_freer @99 - png_malloc_default @100 - png_free_default @101 png_error @102 png_chunk_error @103 png_err @104 png_warning @105 diff -ru4NwbB libpng-1.6.0beta33/scripts/symbols.def.orig libpng-1.7.0alpha02/scripts/symbols.def.orig --- libpng-1.6.0beta33/scripts/symbols.def.orig 1969-12-31 18:00:00.000000000 -0600 +++ libpng-1.7.0alpha02/scripts/symbols.def.orig 2012-12-16 19:27:58.441350830 -0600 @@ -0,0 +1,245 @@ +;-------------------------------------------------------------- +; LIBPNG symbol list as a Win32 DEF file +; Contains all the symbols that can be exported from libpng +;-------------------------------------------------------------- +LIBRARY + +EXPORTS +;Version 1.7.0alpha02 + png_access_version_number @1 + png_set_sig_bytes @2 + png_sig_cmp @3 + png_create_read_struct @4 + png_create_write_struct @5 + png_get_compression_buffer_size @6 + png_set_compression_buffer_size @7 + png_set_longjmp_fn @8 + png_longjmp @9 + png_create_read_struct_2 @11 + png_create_write_struct_2 @12 + png_write_sig @13 + png_write_chunk @14 + png_write_chunk_start @15 + png_write_chunk_data @16 + png_write_chunk_end @17 + png_create_info_struct @18 + png_write_info_before_PLTE @20 + png_write_info @21 + png_read_info @22 + png_convert_from_struct_tm @24 + png_convert_from_time_t @25 + png_set_expand @26 + png_set_expand_gray_1_2_4_to_8 @27 + png_set_palette_to_rgb @28 + png_set_tRNS_to_alpha @29 + png_set_bgr @30 + png_set_gray_to_rgb @31 + png_set_rgb_to_gray @32 + png_set_rgb_to_gray_fixed @33 + png_get_rgb_to_gray_status @34 + png_build_grayscale_palette @35 + png_set_strip_alpha @36 + png_set_swap_alpha @37 + png_set_invert_alpha @38 + png_set_filler @39 + png_set_add_alpha @40 + png_set_swap @41 + png_set_packing @42 + png_set_packswap @43 + png_set_shift @44 + png_set_interlace_handling @45 + png_set_invert_mono @46 + png_set_background @47 + png_set_strip_16 @48 + png_set_quantize @49 + png_set_gamma @50 + png_set_flush @51 + png_write_flush @52 + png_start_read_image @53 + png_read_update_info @54 + png_read_rows @55 + png_read_row @56 + png_read_image @57 + png_write_row @58 + png_write_rows @59 + png_write_image @60 + png_write_end @61 + png_read_end @62 + png_destroy_info_struct @63 + png_destroy_read_struct @64 + png_destroy_write_struct @65 + png_set_crc_action @66 + png_set_filter @67 + png_set_filter_heuristics @68 + png_set_compression_level @69 + png_set_compression_mem_level @70 + png_set_compression_strategy @71 + png_set_compression_window_bits @72 + png_set_compression_method @73 + png_init_io @74 + png_set_error_fn @75 + png_get_error_ptr @76 + png_set_write_fn @77 + png_set_read_fn @78 + png_get_io_ptr @79 + png_set_read_status_fn @80 + png_set_write_status_fn @81 + png_set_mem_fn @82 + png_get_mem_ptr @83 + png_set_read_user_transform_fn @84 + png_set_write_user_transform_fn @85 + png_set_user_transform_info @86 + png_get_user_transform_ptr @87 + png_set_read_user_chunk_fn @88 + png_get_user_chunk_ptr @89 + png_set_progressive_read_fn @90 + png_get_progressive_ptr @91 + png_process_data @92 + png_progressive_combine_row @93 + png_malloc @94 + png_calloc @95 + png_malloc_warn @96 + png_free @97 + png_free_data @98 + png_malloc_default @100 + png_free_default @101 + png_error @102 + png_chunk_error @103 + png_err @104 + png_warning @105 + png_chunk_warning @106 + png_benign_error @107 + png_chunk_benign_error @108 + png_set_benign_errors @109 + png_get_valid @110 + png_get_rowbytes @111 + png_get_rows @112 + png_set_rows @113 + png_get_channels @114 + png_get_image_width @115 + png_get_image_height @116 + png_get_bit_depth @117 + png_get_color_type @118 + png_get_filter_type @119 + png_get_interlace_type @120 + png_get_compression_type @121 + png_get_pixels_per_meter @122 + png_get_x_pixels_per_meter @123 + png_get_y_pixels_per_meter @124 + png_get_pixel_aspect_ratio @125 + png_get_x_offset_pixels @126 + png_get_y_offset_pixels @127 + png_get_x_offset_microns @128 + png_get_y_offset_microns @129 + png_get_signature @130 + png_get_bKGD @131 + png_set_bKGD @132 + png_get_cHRM @133 + png_get_cHRM_fixed @134 + png_set_cHRM @135 + png_set_cHRM_fixed @136 + png_get_gAMA @137 + png_get_gAMA_fixed @138 + png_set_gAMA @139 + png_set_gAMA_fixed @140 + png_get_hIST @141 + png_set_hIST @142 + png_get_IHDR @143 + png_set_IHDR @144 + png_get_oFFs @145 + png_set_oFFs @146 + png_get_pCAL @147 + png_set_pCAL @148 + png_get_pHYs @149 + png_set_pHYs @150 + png_get_PLTE @151 + png_set_PLTE @152 + png_get_sBIT @153 + png_set_sBIT @154 + png_get_sRGB @155 + png_set_sRGB @156 + png_set_sRGB_gAMA_and_cHRM @157 + png_get_iCCP @158 + png_set_iCCP @159 + png_get_sPLT @160 + png_set_sPLT @161 + png_get_text @162 + png_set_text @163 + png_get_tIME @164 + png_set_tIME @165 + png_get_tRNS @166 + png_set_tRNS @167 + png_get_sCAL @168 + png_get_sCAL_s @169 + png_set_sCAL @170 + png_set_sCAL_s @171 + png_set_keep_unknown_chunks @172 + png_handle_as_unknown @173 + png_set_unknown_chunks @174 + png_set_unknown_chunk_location @175 + png_get_unknown_chunks @176 + png_set_invalid @177 + png_read_png @178 + png_write_png @179 + png_get_copyright @180 + png_get_header_ver @181 + png_get_header_version @182 + png_get_libpng_ver @183 + png_permit_mng_features @184 + png_set_strip_error_numbers @185 + png_set_user_limits @186 + png_get_user_width_max @187 + png_get_user_height_max @188 + png_set_chunk_cache_max @189 + png_get_chunk_cache_max @190 + png_set_chunk_malloc_max @191 + png_get_chunk_malloc_max @192 + png_get_pixels_per_inch @193 + png_get_x_pixels_per_inch @194 + png_get_y_pixels_per_inch @195 + png_get_x_offset_inches @196 + png_get_y_offset_inches @197 + png_get_pHYs_dpi @198 + png_get_io_state @199 + png_get_uint_32 @201 + png_get_uint_16 @202 + png_get_int_32 @203 + png_get_uint_31 @204 + png_save_uint_32 @205 + png_save_int_32 @206 + png_save_uint_16 @207 + png_set_gamma_fixed @208 + png_set_filter_heuristics_fixed @209 + png_get_pixel_aspect_ratio_fixed @210 + png_get_x_offset_inches_fixed @211 + png_get_y_offset_inches_fixed @212 + png_set_sCAL_fixed @213 + png_get_sCAL_fixed @214 + png_set_background_fixed @215 + png_get_io_chunk_type @216 + png_get_current_row_number @217 + png_get_current_pass_number @218 + png_process_data_pause @219 + png_process_data_skip @220 + png_set_expand_16 @221 + png_set_text_compression_level @222 + png_set_text_compression_mem_level @223 + png_set_text_compression_strategy @224 + png_set_text_compression_window_bits @225 + png_set_text_compression_method @226 + png_set_alpha_mode @227 + png_set_alpha_mode_fixed @228 + png_set_scale_16 @229 + png_get_cHRM_XYZ @230 + png_get_cHRM_XYZ_fixed @231 + png_set_cHRM_XYZ @232 + png_set_cHRM_XYZ_fixed @233 + png_image_begin_read_from_file @234 + png_image_begin_read_from_stdio @235 + png_image_begin_read_from_memory @236 + png_image_finish_read @237 + png_image_free @238 + png_image_write_to_file @239 + png_image_write_to_stdio @240 + png_convert_to_rfc1123_buffer @241 + png_set_check_for_invalid_index @242