diff options
Diffstat (limited to 'src/3rdparty/libpng/pngrutil.c')
| -rw-r--r-- | src/3rdparty/libpng/pngrutil.c | 1531 |
1 files changed, 1037 insertions, 494 deletions
diff --git a/src/3rdparty/libpng/pngrutil.c b/src/3rdparty/libpng/pngrutil.c index 4c3cd53813..aa592ccfbd 100644 --- a/src/3rdparty/libpng/pngrutil.c +++ b/src/3rdparty/libpng/pngrutil.c @@ -1,8 +1,8 @@ /* pngrutil.c - utilities to read a PNG file * - * Last changed in libpng 1.5.1 [February 3, 2011] - * Copyright (c) 1998-2011 Glenn Randers-Pehrson + * Last changed in libpng 1.5.10 [March 8, 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.) * @@ -87,10 +87,10 @@ png_int_32 (PNGAPI png_get_int_32)(png_const_bytep buf) { png_uint_32 uval = png_get_uint_32(buf); - if ((uval & 0x80000000L) == 0) /* non-negative */ + if ((uval & 0x80000000) == 0) /* non-negative */ return uval; - uval = (uval ^ 0xffffffffL) + 1; /* 2's complement: -x = ~x+1 */ + uval = (uval ^ 0xffffffff) + 1; /* 2's complement: -x = ~x+1 */ return -(png_int_32)uval; } @@ -165,14 +165,14 @@ png_read_chunk_header(png_structp png_ptr) length = png_get_uint_31(png_ptr, buf); /* Put the chunk name into png_ptr->chunk_name. */ - png_memcpy(png_ptr->chunk_name, buf + 4, 4); + png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(buf+4); - png_debug2(0, "Reading %s chunk, length = %u", - png_ptr->chunk_name, length); + png_debug2(0, "Reading %lx chunk, length = %lu", + (unsigned long)png_ptr->chunk_name, (unsigned long)length); /* Reset the crc and run it over the chunk name. */ png_reset_crc(png_ptr); - png_calculate_crc(png_ptr, png_ptr->chunk_name, 4); + png_calculate_crc(png_ptr, buf + 4, 4); /* Check to see if chunk name is valid. */ png_check_chunk_name(png_ptr, png_ptr->chunk_name); @@ -218,10 +218,9 @@ png_crc_finish(png_structp png_ptr, png_uint_32 skip) if (png_crc_error(png_ptr)) { - if (((png_ptr->chunk_name[0] & 0x20) && /* Ancillary */ - !(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN)) || - (!(png_ptr->chunk_name[0] & 0x20) && /* Critical */ - (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_USE))) + if (PNG_CHUNK_ANCILLIARY(png_ptr->chunk_name) ? + !(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN) : + (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_USE)) { png_chunk_warning(png_ptr, "CRC error"); } @@ -248,14 +247,14 @@ png_crc_error(png_structp png_ptr) png_uint_32 crc; int need_crc = 1; - if (png_ptr->chunk_name[0] & 0x20) /* ancillary */ + if (PNG_CHUNK_ANCILLIARY(png_ptr->chunk_name)) { if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_MASK) == (PNG_FLAG_CRC_ANCILLARY_USE | PNG_FLAG_CRC_ANCILLARY_NOWARN)) need_crc = 0; } - else /* critical */ + else /* critical */ { if (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_IGNORE) need_crc = 0; @@ -278,8 +277,7 @@ png_crc_error(png_structp png_ptr) return (0); } -#if defined(PNG_READ_zTXt_SUPPORTED) || defined(PNG_READ_iTXt_SUPPORTED) || \ - defined(PNG_READ_iCCP_SUPPORTED) +#ifdef PNG_READ_COMPRESSED_TEXT_SUPPORTED static png_size_t png_inflate(png_structp png_ptr, png_bytep data, png_size_t size, png_bytep output, png_size_t output_size) @@ -303,7 +301,7 @@ png_inflate(png_structp png_ptr, png_bytep data, png_size_t size, { int ret, avail; - /* The setting of 'avail_in' used to be outside the loop, by setting it + /* The setting of 'avail_in' used to be outside the loop; by setting it * inside it is possible to chunk the input to zlib and simply rely on * zlib to advance the 'next_in' pointer. This allows arbitrary amounts o * data to be passed through zlib at the unavoidable cost of requiring a @@ -370,41 +368,31 @@ png_inflate(png_structp png_ptr, png_bytep data, png_size_t size, * and the error message is dumped into the uncompressed * buffer if available. */ +# ifdef PNG_WARNINGS_SUPPORTED { - PNG_CONST char *msg; -#ifdef PNG_CONSOLE_IO_SUPPORTED - char umsg[52]; -#endif + png_const_charp msg; + if (png_ptr->zstream.msg != 0) msg = png_ptr->zstream.msg; - else + else switch (ret) { -#ifdef PNG_CONSOLE_IO_SUPPORTED - switch (ret) - { - case Z_BUF_ERROR: - msg = "Buffer error in compressed datastream in %s chunk"; - break; - - case Z_DATA_ERROR: - msg = "Data error in compressed datastream in %s chunk"; - break; + case Z_BUF_ERROR: + msg = "Buffer error in compressed datastream"; + break; - default: - msg = "Incomplete compressed datastream in %s chunk"; - break; - } + case Z_DATA_ERROR: + msg = "Data error in compressed datastream"; + break; - png_snprintf(umsg, sizeof umsg, msg, png_ptr->chunk_name); - msg = umsg; -#else - msg = "Damaged compressed datastream in chunk other than IDAT"; -#endif + default: + msg = "Incomplete compressed datastream"; + break; } - png_warning(png_ptr, msg); + png_chunk_warning(png_ptr, msg); } +# endif /* 0 means an error - notice that this code simply ignores * zero length compressed chunks as a result. @@ -438,21 +426,22 @@ png_decompress_chunk(png_structp png_ptr, int comp_type, png_size_t expanded_size = png_inflate(png_ptr, (png_bytep)(png_ptr->chunkdata + prefix_size), chunklength - prefix_size, - 0, /*output*/ - 0); /*output size*/ + 0, /* output */ + 0); /* output size */ /* Now check the limits on this chunk - if the limit fails the * compressed data will be removed, the prefix will remain. */ -#ifdef PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED - if (png_ptr->user_chunk_malloc_max && + if (prefix_size >= (~(png_size_t)0) - 1 || + expanded_size >= (~(png_size_t)0) - 1 - prefix_size +#ifdef PNG_USER_LIMITS_SUPPORTED + || (png_ptr->user_chunk_malloc_max && (prefix_size + expanded_size >= png_ptr->user_chunk_malloc_max - 1)) #else -# ifdef PNG_USER_CHUNK_MALLOC_MAX - if ((PNG_USER_CHUNK_MALLOC_MAX > 0) && + || ((PNG_USER_CHUNK_MALLOC_MAX > 0) && prefix_size + expanded_size >= PNG_USER_CHUNK_MALLOC_MAX - 1) -# endif #endif + ) png_warning(png_ptr, "Exceeded size limit while expanding chunk"); /* If the size is zero either there was an error and a message @@ -460,16 +449,11 @@ png_decompress_chunk(png_structp png_ptr, int comp_type, * and we have nothing to do - the code will exit through the * error case below. */ -#if defined(PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED) || \ - defined(PNG_USER_CHUNK_MALLOC_MAX) else if (expanded_size > 0) -#else - if (expanded_size > 0) -#endif { /* Success (maybe) - really uncompress the chunk. */ png_size_t new_size = 0; - png_charp text = png_malloc_warn(png_ptr, + png_charp text = (png_charp)png_malloc_warn(png_ptr, prefix_size + expanded_size + 1); if (text != NULL) @@ -500,15 +484,9 @@ png_decompress_chunk(png_structp png_ptr, int comp_type, else /* if (comp_type != PNG_COMPRESSION_TYPE_BASE) */ { -#ifdef PNG_STDIO_SUPPORTED - char umsg[50]; - - png_snprintf(umsg, sizeof umsg, - "Unknown zTXt compression type %d", comp_type); - png_warning(png_ptr, umsg); -#else - png_warning(png_ptr, "Unknown zTXt compression type"); -#endif + PNG_WARNING_PARAMETERS(p) + png_warning_parameter_signed(p, 1, PNG_NUMBER_FORMAT_d, comp_type); + png_formatted_warning(png_ptr, p, "Unknown compression type @1"); /* The recovery is to simply drop the data. */ } @@ -518,7 +496,7 @@ png_decompress_chunk(png_structp png_ptr, int comp_type, * amount of compressed data. */ { - png_charp text = png_malloc_warn(png_ptr, prefix_size + 1); + png_charp text = (png_charp)png_malloc_warn(png_ptr, prefix_size + 1); if (text != NULL) { @@ -536,7 +514,7 @@ png_decompress_chunk(png_structp png_ptr, int comp_type, *newlength = prefix_size; } -#endif +#endif /* PNG_READ_COMPRESSED_TEXT_SUPPORTED */ /* Read and check the IDHR chunk */ void /* PRIVATE */ @@ -844,14 +822,12 @@ png_handle_gAMA(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) # ifdef PNG_READ_sRGB_SUPPORTED if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sRGB)) { - if (PNG_OUT_OF_RANGE(igamma, 45500L, 500)) + if (PNG_OUT_OF_RANGE(igamma, 45500, 500)) { - png_warning(png_ptr, - "Ignoring incorrect gAMA value when sRGB is also present"); - -# ifdef PNG_CONSOLE_IO_SUPPORTED - fprintf(stderr, "gamma = (%d/100000)", (int)igamma); -# endif + PNG_WARNING_PARAMETERS(p) + png_warning_parameter_signed(p, 1, PNG_NUMBER_FORMAT_fixed, igamma); + png_formatted_warning(png_ptr, p, + "Ignoring incorrect gAMA value @1 when sRGB is also present"); return; } } @@ -961,7 +937,7 @@ png_handle_cHRM(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) else if (png_ptr->mode & PNG_HAVE_PLTE) /* Should be an error, but we can cope with it */ - png_warning(png_ptr, "Missing PLTE before cHRM"); + png_warning(png_ptr, "Out of place cHRM chunk"); if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM) # ifdef PNG_READ_sRGB_SUPPORTED @@ -1013,28 +989,112 @@ png_handle_cHRM(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) { if (PNG_OUT_OF_RANGE(x_white, 31270, 1000) || PNG_OUT_OF_RANGE(y_white, 32900, 1000) || - PNG_OUT_OF_RANGE(x_red, 64000L, 1000) || + PNG_OUT_OF_RANGE(x_red, 64000, 1000) || PNG_OUT_OF_RANGE(y_red, 33000, 1000) || PNG_OUT_OF_RANGE(x_green, 30000, 1000) || - PNG_OUT_OF_RANGE(y_green, 60000L, 1000) || + PNG_OUT_OF_RANGE(y_green, 60000, 1000) || PNG_OUT_OF_RANGE(x_blue, 15000, 1000) || PNG_OUT_OF_RANGE(y_blue, 6000, 1000)) { - png_warning(png_ptr, - "Ignoring incorrect cHRM value when sRGB is also present"); - -#ifdef PNG_CONSOLE_IO_SUPPORTED - fprintf(stderr, "wx=%d, wy=%d, rx=%d, ry=%d\n", - x_white, y_white, x_red, y_red); - - fprintf(stderr, "gx=%d, gy=%d, bx=%d, by=%d\n", - x_green, y_green, x_blue, y_blue); -#endif /* PNG_CONSOLE_IO_SUPPORTED */ + PNG_WARNING_PARAMETERS(p) + + png_warning_parameter_signed(p, 1, PNG_NUMBER_FORMAT_fixed, x_white); + png_warning_parameter_signed(p, 2, PNG_NUMBER_FORMAT_fixed, y_white); + png_warning_parameter_signed(p, 3, PNG_NUMBER_FORMAT_fixed, x_red); + png_warning_parameter_signed(p, 4, PNG_NUMBER_FORMAT_fixed, y_red); + png_warning_parameter_signed(p, 5, PNG_NUMBER_FORMAT_fixed, x_green); + png_warning_parameter_signed(p, 6, PNG_NUMBER_FORMAT_fixed, y_green); + png_warning_parameter_signed(p, 7, PNG_NUMBER_FORMAT_fixed, x_blue); + png_warning_parameter_signed(p, 8, PNG_NUMBER_FORMAT_fixed, y_blue); + + png_formatted_warning(png_ptr, p, + "Ignoring incorrect cHRM white(@1,@2) r(@3,@4)g(@5,@6)b(@7,@8) " + "when sRGB is also present"); } return; } #endif /* PNG_READ_sRGB_SUPPORTED */ +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED + /* Store the _white values as default coefficients for the rgb to gray + * operation if it is supported. Check if the transform is already set to + * avoid destroying the transform values. + */ + if (!png_ptr->rgb_to_gray_coefficients_set) + { + /* png_set_background has not been called and we haven't seen an sRGB + * chunk yet. Find the XYZ of the three end points. + */ + png_XYZ XYZ; + png_xy xy; + + xy.redx = x_red; + xy.redy = y_red; + xy.greenx = x_green; + xy.greeny = y_green; + xy.bluex = x_blue; + xy.bluey = y_blue; + xy.whitex = x_white; + xy.whitey = y_white; + + if (png_XYZ_from_xy_checked(png_ptr, &XYZ, xy)) + { + /* The success case, because XYZ_from_xy normalises to a reference + * white Y of 1.0 we just need to scale the numbers. This should + * always work just fine. It is an internal error if this overflows. + */ + { + png_fixed_point r, g, b; + if (png_muldiv(&r, XYZ.redY, 32768, PNG_FP_1) && + r >= 0 && r <= 32768 && + png_muldiv(&g, XYZ.greenY, 32768, PNG_FP_1) && + g >= 0 && g <= 32768 && + png_muldiv(&b, XYZ.blueY, 32768, PNG_FP_1) && + b >= 0 && b <= 32768 && + r+g+b <= 32769) + { + /* We allow 0 coefficients here. r+g+b may be 32769 if two or + * all of the coefficients were rounded up. Handle this by + * reducing the *largest* coefficient by 1; this matches the + * approach used for the default coefficients in pngrtran.c + */ + int add = 0; + + if (r+g+b > 32768) + add = -1; + else if (r+g+b < 32768) + add = 1; + + if (add != 0) + { + if (g >= r && g >= b) + g += add; + else if (r >= g && r >= b) + r += add; + else + b += add; + } + + /* Check for an internal error. */ + if (r+g+b != 32768) + png_error(png_ptr, + "internal error handling cHRM coefficients"); + + png_ptr->rgb_to_gray_red_coeff = (png_uint_16)r; + png_ptr->rgb_to_gray_green_coeff = (png_uint_16)g; + } + + /* This is a png_error at present even though it could be ignored - + * it should never happen, but it is important that if it does, the + * bug is fixed. + */ + else + png_error(png_ptr, "internal error handling cHRM->XYZ"); + } + } + } +#endif + png_set_cHRM_fixed(png_ptr, info_ptr, x_white, y_white, x_red, y_red, x_green, y_green, x_blue, y_blue); } @@ -1094,13 +1154,15 @@ png_handle_sRGB(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) #if defined(PNG_READ_gAMA_SUPPORTED) && defined(PNG_READ_GAMMA_SUPPORTED) if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_gAMA)) { - if (PNG_OUT_OF_RANGE(info_ptr->gamma, 45500L, 500)) + if (PNG_OUT_OF_RANGE(info_ptr->gamma, 45500, 500)) { - png_warning(png_ptr, - "Ignoring incorrect gAMA value when sRGB is also present"); -#ifdef PNG_CONSOLE_IO_SUPPORTED - fprintf(stderr, "incorrect gamma=(%d/100000)\n", info_ptr->gamma); -#endif + PNG_WARNING_PARAMETERS(p) + + png_warning_parameter_signed(p, 1, PNG_NUMBER_FORMAT_fixed, + info_ptr->gamma); + + png_formatted_warning(png_ptr, p, + "Ignoring incorrect gAMA value @1 when sRGB is also present"); } } #endif /* PNG_READ_gAMA_SUPPORTED */ @@ -1109,10 +1171,10 @@ png_handle_sRGB(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM)) if (PNG_OUT_OF_RANGE(info_ptr->x_white, 31270, 1000) || PNG_OUT_OF_RANGE(info_ptr->y_white, 32900, 1000) || - PNG_OUT_OF_RANGE(info_ptr->x_red, 64000L, 1000) || + PNG_OUT_OF_RANGE(info_ptr->x_red, 64000, 1000) || PNG_OUT_OF_RANGE(info_ptr->y_red, 33000, 1000) || PNG_OUT_OF_RANGE(info_ptr->x_green, 30000, 1000) || - PNG_OUT_OF_RANGE(info_ptr->y_green, 60000L, 1000) || + PNG_OUT_OF_RANGE(info_ptr->y_green, 60000, 1000) || PNG_OUT_OF_RANGE(info_ptr->x_blue, 15000, 1000) || PNG_OUT_OF_RANGE(info_ptr->y_blue, 6000, 1000)) { @@ -1121,6 +1183,47 @@ png_handle_sRGB(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) } #endif /* PNG_READ_cHRM_SUPPORTED */ + /* This is recorded for use when handling the cHRM chunk above. An sRGB + * chunk unconditionally overwrites the coefficients for grayscale conversion + * too. + */ + png_ptr->is_sRGB = 1; + +# ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED + /* Don't overwrite user supplied values: */ + if (!png_ptr->rgb_to_gray_coefficients_set) + { + /* These numbers come from the sRGB specification (or, since one has to + * pay much money to get a copy, the wikipedia sRGB page) the + * chromaticity values quoted have been inverted to get the reverse + * transformation from RGB to XYZ and the 'Y' coefficients scaled by + * 32768 (then rounded). + * + * sRGB and ITU Rec-709 both truncate the values for the D65 white + * point to four digits and, even though it actually stores five + * digits, the PNG spec gives the truncated value. + * + * This means that when the chromaticities are converted back to XYZ + * end points we end up with (6968,23435,2366), which, as described in + * pngrtran.c, would overflow. If the five digit precision and up is + * used we get, instead: + * + * 6968*R + 23435*G + 2365*B + * + * (Notice that this rounds the blue coefficient down, rather than the + * choice used in pngrtran.c which is to round the green one down.) + */ + png_ptr->rgb_to_gray_red_coeff = 6968; /* 0.212639005871510 */ + png_ptr->rgb_to_gray_green_coeff = 23434; /* 0.715168678767756 */ + /* png_ptr->rgb_to_gray_blue_coeff = 2366; 0.072192315360734 */ + + /* The following keeps the cHRM chunk from destroying the + * coefficients again in the event that it follows the sRGB chunk. + */ + png_ptr->rgb_to_gray_coefficients_set = 1; + } +# endif + png_set_sRGB_gAMA_and_cHRM(png_ptr, info_ptr, intent); } #endif /* PNG_READ_sRGB_SUPPORTED */ @@ -1154,13 +1257,16 @@ png_handle_iCCP(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) /* Should be an error, but we can cope with it */ png_warning(png_ptr, "Out of place iCCP chunk"); - if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_iCCP)) + if ((png_ptr->mode & PNG_HAVE_iCCP) || (info_ptr != NULL && + (info_ptr->valid & (PNG_INFO_iCCP|PNG_INFO_sRGB)))) { png_warning(png_ptr, "Duplicate iCCP chunk"); png_crc_finish(png_ptr, length); return; } + png_ptr->mode |= PNG_HAVE_iCCP; + #ifdef PNG_MAX_MALLOC_64K if (length > (png_uint_32)65535L) { @@ -1172,7 +1278,7 @@ png_handle_iCCP(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) png_free(png_ptr, png_ptr->chunkdata); png_ptr->chunkdata = (png_charp)png_malloc(png_ptr, length + 1); - slength = (png_size_t)length; + slength = length; png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength); if (png_crc_finish(png_ptr, skip)) @@ -1240,23 +1346,15 @@ png_handle_iCCP(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) /* And the following guarantees that profile_size == profile_length. */ if (profile_size > profile_length) { + PNG_WARNING_PARAMETERS(p) + png_free(png_ptr, png_ptr->chunkdata); png_ptr->chunkdata = NULL; -#ifdef PNG_STDIO_SUPPORTED - { - char umsg[80]; - - png_snprintf2(umsg, 80, - "Ignoring iCCP chunk with declared size = %u " - "and actual length = %u", - (unsigned int) profile_size, - (unsigned int) profile_length); - png_warning(png_ptr, umsg); - } -#else - png_warning(png_ptr, - "Ignoring iCCP chunk with uncompressed size mismatch"); -#endif + + png_warning_parameter_unsigned(p, 1, PNG_NUMBER_FORMAT_u, profile_size); + png_warning_parameter_unsigned(p, 2, PNG_NUMBER_FORMAT_u, profile_length); + png_formatted_warning(png_ptr, p, + "Ignoring iCCP chunk with declared size = @1 and actual length = @2"); return; } @@ -1275,9 +1373,7 @@ png_handle_sPLT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) { png_bytep entry_start; png_sPLT_t new_palette; -#ifdef PNG_POINTER_INDEXING_SUPPORTED png_sPLT_entryp pp; -#endif png_uint_32 data_length; int entry_size, i; png_uint_32 skip = 0; @@ -1332,7 +1428,7 @@ png_handle_sPLT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) * that the PNG_MAX_MALLOC_64K test is enabled in this case, but this is a * potential breakage point if the types in pngconf.h aren't exactly right. */ - slength = (png_size_t)length; + slength = length; png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength); if (png_crc_finish(png_ptr, skip)) @@ -1442,7 +1538,7 @@ png_handle_sPLT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) pp[i].alpha = png_get_uint_16(entry_start); entry_start += 2; } - pp->frequency = png_get_uint_16(entry_start); entry_start += 2; + pp[i].frequency = png_get_uint_16(entry_start); entry_start += 2; } #endif @@ -1567,6 +1663,7 @@ png_handle_bKGD(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) { png_size_t truelen; png_byte buf[6]; + png_color_16 background; png_debug(1, "in png_handle_bKGD"); @@ -1623,7 +1720,7 @@ png_handle_bKGD(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) */ if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) { - png_ptr->background.index = buf[0]; + background.index = buf[0]; if (info_ptr && info_ptr->num_palette) { @@ -1633,33 +1730,36 @@ png_handle_bKGD(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) return; } - png_ptr->background.red = - (png_uint_16)png_ptr->palette[buf[0]].red; + background.red = (png_uint_16)png_ptr->palette[buf[0]].red; + background.green = (png_uint_16)png_ptr->palette[buf[0]].green; + background.blue = (png_uint_16)png_ptr->palette[buf[0]].blue; + } - png_ptr->background.green = - (png_uint_16)png_ptr->palette[buf[0]].green; + else + background.red = background.green = background.blue = 0; - png_ptr->background.blue = - (png_uint_16)png_ptr->palette[buf[0]].blue; - } + background.gray = 0; } else if (!(png_ptr->color_type & PNG_COLOR_MASK_COLOR)) /* GRAY */ { - png_ptr->background.red = - png_ptr->background.green = - png_ptr->background.blue = - png_ptr->background.gray = png_get_uint_16(buf); + background.index = 0; + background.red = + background.green = + background.blue = + background.gray = png_get_uint_16(buf); } else { - png_ptr->background.red = png_get_uint_16(buf); - png_ptr->background.green = png_get_uint_16(buf + 2); - png_ptr->background.blue = png_get_uint_16(buf + 4); + background.index = 0; + background.red = png_get_uint_16(buf); + background.green = png_get_uint_16(buf + 2); + background.blue = png_get_uint_16(buf + 4); + background.gray = 0; } - png_set_bKGD(png_ptr, info_ptr, &(png_ptr->background)); + png_set_bKGD(png_ptr, info_ptr, &background); } #endif @@ -1696,16 +1796,16 @@ png_handle_hIST(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) return; } - num = length / 2 ; - - if (num != (unsigned int)png_ptr->num_palette || num > - (unsigned int)PNG_MAX_PALETTE_LENGTH) + if (length > 2*PNG_MAX_PALETTE_LENGTH || + length != (unsigned int) (2*png_ptr->num_palette)) { png_warning(png_ptr, "Incorrect hIST chunk length"); png_crc_finish(png_ptr, length); return; } + num = length / 2 ; + for (i = 0; i < num; i++) { png_byte buf[2]; @@ -1855,7 +1955,7 @@ png_handle_pCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) return; } - slength = (png_size_t)length; + slength = length; png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength); if (png_crc_finish(png_ptr, 0)) @@ -1984,6 +2084,14 @@ png_handle_sCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) return; } + /* Need unit type, width, \0, height: minimum 4 bytes */ + else if (length < 4) + { + png_warning(png_ptr, "sCAL chunk too short"); + png_crc_finish(png_ptr, length); + return; + } + png_debug1(2, "Allocating and reading sCAL chunk data (%u bytes)", length + 1); @@ -1996,7 +2104,7 @@ png_handle_sCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) return; } - slength = (png_size_t)length; + slength = length; png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength); png_ptr->chunkdata[slength] = 0x00; /* Null terminate the last string */ @@ -2019,23 +2127,29 @@ png_handle_sCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) /* Validate the ASCII numbers, need two ASCII numbers separated by * a '\0' and they need to fit exactly in the chunk data. */ - i = 0; + i = 1; state = 0; - if (png_ptr->chunkdata[1] == 45 /* negative width */ || - !png_check_fp_number(png_ptr->chunkdata, slength, &state, &i) || + if (!png_check_fp_number(png_ptr->chunkdata, slength, &state, &i) || i >= slength || png_ptr->chunkdata[i++] != 0) png_warning(png_ptr, "Invalid sCAL chunk ignored: bad width format"); + else if (!PNG_FP_IS_POSITIVE(state)) + png_warning(png_ptr, "Invalid sCAL chunk ignored: non-positive width"); + else { png_size_t heighti = i; - if (png_ptr->chunkdata[i] == 45 /* negative height */ || - !png_check_fp_number(png_ptr->chunkdata, slength, &state, &i) || + state = 0; + if (!png_check_fp_number(png_ptr->chunkdata, slength, &state, &i) || i != slength) png_warning(png_ptr, "Invalid sCAL chunk ignored: bad height format"); + else if (!PNG_FP_IS_POSITIVE(state)) + png_warning(png_ptr, + "Invalid sCAL chunk ignored: non-positive height"); + else /* This is the (only) success case. */ png_set_sCAL_s(png_ptr, info_ptr, png_ptr->chunkdata[0], @@ -2150,7 +2264,7 @@ png_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) return; } - slength = (png_size_t)length; + slength = length; png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength); if (png_crc_finish(png_ptr, skip)) @@ -2258,7 +2372,7 @@ png_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) return; } - slength = (png_size_t)length; + slength = length; png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength); if (png_crc_finish(png_ptr, 0)) @@ -2389,7 +2503,7 @@ png_handle_iTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) return; } - slength = (png_size_t)length; + slength = length; png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength); if (png_crc_finish(png_ptr, 0)) @@ -2425,6 +2539,14 @@ png_handle_iTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) comp_type = *lang++; } + if (comp_type || (comp_flag && comp_flag != PNG_TEXT_COMPRESSION_zTXt)) + { + png_warning(png_ptr, "Unknown iTXt compression type or method"); + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + return; + } + for (lang_key = lang; *lang_key; lang_key++) /* Empty loop */ ; @@ -2525,16 +2647,14 @@ png_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) if (png_ptr->mode & PNG_HAVE_IDAT) { - PNG_IDAT; - - if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) /* Not an IDAT */ + if (png_ptr->chunk_name != png_IDAT) png_ptr->mode |= PNG_AFTER_IDAT; } - if (!(png_ptr->chunk_name[0] & 0x20)) + if (PNG_CHUNK_CRITICAL(png_ptr->chunk_name)) { #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED - if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) != + if (png_chunk_unknown_handling(png_ptr, png_ptr->chunk_name) != PNG_HANDLE_CHUNK_ALWAYS #ifdef PNG_READ_USER_CHUNKS_SUPPORTED && png_ptr->read_user_chunk_fn == NULL @@ -2552,21 +2672,20 @@ png_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) ) { #ifdef PNG_MAX_MALLOC_64K - if (length > (png_uint_32)65535L) + if (length > 65535) { png_warning(png_ptr, "unknown chunk too large to fit in memory"); - skip = length - (png_uint_32)65535L; - length = (png_uint_32)65535L; + skip = length - 65535; + length = 65535; } #endif - png_memcpy((png_charp)png_ptr->unknown_chunk.name, - (png_charp)png_ptr->chunk_name, - png_sizeof(png_ptr->unknown_chunk.name)); - - png_ptr->unknown_chunk.name[png_sizeof(png_ptr->unknown_chunk.name)-1] - = '\0'; - + /* TODO: this code is very close to the unknown handling in pngpread.c, + * maybe it can be put into a common utility routine? + * png_struct::unknown_chunk is just used as a temporary variable, along + * with the data into which the chunk is read. These can be eliminated. + */ + PNG_CSTRING_FROM_CHUNK(png_ptr->unknown_chunk.name, png_ptr->chunk_name); png_ptr->unknown_chunk.size = (png_size_t)length; if (length == 0) @@ -2575,7 +2694,7 @@ png_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) else { png_ptr->unknown_chunk.data = (png_bytep)png_malloc(png_ptr, length); - png_crc_read(png_ptr, (png_bytep)png_ptr->unknown_chunk.data, length); + png_crc_read(png_ptr, png_ptr->unknown_chunk.data, length); } #ifdef PNG_READ_USER_CHUNKS_SUPPORTED @@ -2592,10 +2711,10 @@ png_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) if (ret == 0) { - if (!(png_ptr->chunk_name[0] & 0x20)) + if (PNG_CHUNK_CRITICAL(png_ptr->chunk_name)) { #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED - if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) != + if (png_chunk_unknown_handling(png_ptr, png_ptr->chunk_name) != PNG_HANDLE_CHUNK_ALWAYS) #endif png_chunk_error(png_ptr, "unknown critical chunk"); @@ -2632,259 +2751,523 @@ png_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) * the chunk name itself is valid. */ -#define isnonalpha(c) ((c) < 65 || (c) > 122 || ((c) > 90 && (c) < 97)) +/* Bit hacking: the test for an invalid byte in the 4 byte chunk name is: + * + * ((c) < 65 || (c) > 122 || ((c) > 90 && (c) < 97)) + */ void /* PRIVATE */ -png_check_chunk_name(png_structp png_ptr, png_const_bytep chunk_name) +png_check_chunk_name(png_structp png_ptr, png_uint_32 chunk_name) { + int i; + png_debug(1, "in png_check_chunk_name"); - if (isnonalpha(chunk_name[0]) || isnonalpha(chunk_name[1]) || - isnonalpha(chunk_name[2]) || isnonalpha(chunk_name[3])) + + for (i=1; i<=4; ++i) { - png_chunk_error(png_ptr, "invalid chunk type"); + int c = chunk_name & 0xff; + + if (c < 65 || c > 122 || (c > 90 && c < 97)) + png_chunk_error(png_ptr, "invalid chunk type"); + + chunk_name >>= 8; } } -/* Combines the row recently read in with the existing pixels in the - * row. This routine takes care of alpha and transparency if requested. - * This routine also handles the two methods of progressive display - * of interlaced images, depending on the mask value. - * The mask value describes which pixels are to be combined with - * the row. The pattern always repeats every 8 pixels, so just 8 - * bits are needed. A one indicates the pixel is to be combined, - * a zero indicates the pixel is to be skipped. This is in addition - * to any alpha or transparency value associated with the pixel. If - * you want all pixels to be combined, pass 0xff (255) in mask. +/* Combines the row recently read in with the existing pixels in the row. This + * routine takes care of alpha and transparency if requested. This routine also + * handles the two methods of progressive display of interlaced images, + * depending on the 'display' value; if 'display' is true then the whole row + * (dp) is filled from the start by replicating the available pixels. If + * 'display' is false only those pixels present in the pass are filled in. */ - void /* PRIVATE */ -png_combine_row(png_structp png_ptr, png_bytep row, int mask) +png_combine_row(png_structp png_ptr, png_bytep dp, int display) { + unsigned int pixel_depth = png_ptr->transformed_pixel_depth; + png_const_bytep sp = png_ptr->row_buf + 1; + png_uint_32 row_width = png_ptr->width; + unsigned int pass = png_ptr->pass; + png_bytep end_ptr = 0; + png_byte end_byte = 0; + unsigned int end_mask; + png_debug(1, "in png_combine_row"); - if (mask == 0xff) - { - png_memcpy(row, png_ptr->row_buf + 1, - PNG_ROWBYTES(png_ptr->row_info.pixel_depth, png_ptr->width)); - } + /* Added in 1.5.6: it should not be possible to enter this routine until at + * least one row has been read from the PNG data and transformed. + */ + if (pixel_depth == 0) + png_error(png_ptr, "internal row logic error"); - else + /* Added in 1.5.4: the pixel depth should match the information returned by + * any call to png_read_update_info at this point. Do not continue if we got + * this wrong. + */ + if (png_ptr->info_rowbytes != 0 && png_ptr->info_rowbytes != + PNG_ROWBYTES(pixel_depth, row_width)) + png_error(png_ptr, "internal row size calculation error"); + + /* Don't expect this to ever happen: */ + if (row_width == 0) + png_error(png_ptr, "internal row width error"); + + /* Preserve the last byte in cases where only part of it will be overwritten, + * the multiply below may overflow, we don't care because ANSI-C guarantees + * we get the low bits. + */ + end_mask = (pixel_depth * row_width) & 7; + if (end_mask != 0) + { + /* end_ptr == NULL is a flag to say do nothing */ + end_ptr = dp + PNG_ROWBYTES(pixel_depth, row_width) - 1; + end_byte = *end_ptr; +# ifdef PNG_READ_PACKSWAP_SUPPORTED + if (png_ptr->transformations & PNG_PACKSWAP) /* little-endian byte */ + end_mask = 0xff << end_mask; + + else /* big-endian byte */ +# endif + end_mask = 0xff >> end_mask; + /* end_mask is now the bits to *keep* from the destination row */ + } + + /* For non-interlaced images this reduces to a png_memcpy(). A png_memcpy() + * will also happen if interlacing isn't supported or if the application + * does not call png_set_interlace_handling(). In the latter cases the + * caller just gets a sequence of the unexpanded rows from each interlace + * pass. + */ +#ifdef PNG_READ_INTERLACING_SUPPORTED + if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE) && + pass < 6 && (display == 0 || + /* The following copies everything for 'display' on passes 0, 2 and 4. */ + (display == 1 && (pass & 1) != 0))) { - switch (png_ptr->row_info.pixel_depth) + /* Narrow images may have no bits in a pass; the caller should handle + * this, but this test is cheap: + */ + if (row_width <= PNG_PASS_START_COL(pass)) + return; + + if (pixel_depth < 8) { - case 1: + /* For pixel depths up to 4 bpp the 8-pixel mask can be expanded to fit + * into 32 bits, then a single loop over the bytes using the four byte + * values in the 32-bit mask can be used. For the 'display' option the + * expanded mask may also not require any masking within a byte. To + * make this work the PACKSWAP option must be taken into account - it + * simply requires the pixels to be reversed in each byte. + * + * The 'regular' case requires a mask for each of the first 6 passes, + * the 'display' case does a copy for the even passes in the range + * 0..6. This has already been handled in the test above. + * + * The masks are arranged as four bytes with the first byte to use in + * the lowest bits (little-endian) regardless of the order (PACKSWAP or + * not) of the pixels in each byte. + * + * NOTE: the whole of this logic depends on the caller of this function + * only calling it on rows appropriate to the pass. This function only + * understands the 'x' logic; the 'y' logic is handled by the caller. + * + * The following defines allow generation of compile time constant bit + * masks for each pixel depth and each possibility of swapped or not + * swapped bytes. Pass 'p' is in the range 0..6; 'x', a pixel index, + * is in the range 0..7; and the result is 1 if the pixel is to be + * copied in the pass, 0 if not. 'S' is for the sparkle method, 'B' + * for the block method. + * + * With some compilers a compile time expression of the general form: + * + * (shift >= 32) ? (a >> (shift-32)) : (b >> shift) + * + * Produces warnings with values of 'shift' in the range 33 to 63 + * because the right hand side of the ?: expression is evaluated by + * the compiler even though it isn't used. Microsoft Visual C (various + * versions) and the Intel C compiler are known to do this. To avoid + * this the following macros are used in 1.5.6. This is a temporary + * solution to avoid destabilizing the code during the release process. + */ +# if PNG_USE_COMPILE_TIME_MASKS +# define PNG_LSR(x,s) ((x)>>((s) & 0x1f)) +# define PNG_LSL(x,s) ((x)<<((s) & 0x1f)) +# else +# define PNG_LSR(x,s) ((x)>>(s)) +# define PNG_LSL(x,s) ((x)<<(s)) +# endif +# define S_COPY(p,x) (((p)<4 ? PNG_LSR(0x80088822,(3-(p))*8+(7-(x))) :\ + PNG_LSR(0xaa55ff00,(7-(p))*8+(7-(x)))) & 1) +# define B_COPY(p,x) (((p)<4 ? PNG_LSR(0xff0fff33,(3-(p))*8+(7-(x))) :\ + PNG_LSR(0xff55ff00,(7-(p))*8+(7-(x)))) & 1) + + /* Return a mask for pass 'p' pixel 'x' at depth 'd'. The mask is + * little endian - the first pixel is at bit 0 - however the extra + * parameter 's' can be set to cause the mask position to be swapped + * within each byte, to match the PNG format. This is done by XOR of + * the shift with 7, 6 or 4 for bit depths 1, 2 and 4. + */ +# define PIXEL_MASK(p,x,d,s) \ + (PNG_LSL(((PNG_LSL(1U,(d)))-1),(((x)*(d))^((s)?8-(d):0)))) + + /* Hence generate the appropriate 'block' or 'sparkle' pixel copy mask. + */ +# define S_MASKx(p,x,d,s) (S_COPY(p,x)?PIXEL_MASK(p,x,d,s):0) +# define B_MASKx(p,x,d,s) (B_COPY(p,x)?PIXEL_MASK(p,x,d,s):0) + + /* Combine 8 of these to get the full mask. For the 1-bpp and 2-bpp + * cases the result needs replicating, for the 4-bpp case the above + * generates a full 32 bits. + */ +# define MASK_EXPAND(m,d) ((m)*((d)==1?0x01010101:((d)==2?0x00010001:1))) + +# define S_MASK(p,d,s) MASK_EXPAND(S_MASKx(p,0,d,s) + S_MASKx(p,1,d,s) +\ + S_MASKx(p,2,d,s) + S_MASKx(p,3,d,s) + S_MASKx(p,4,d,s) +\ + S_MASKx(p,5,d,s) + S_MASKx(p,6,d,s) + S_MASKx(p,7,d,s), d) + +# define B_MASK(p,d,s) MASK_EXPAND(B_MASKx(p,0,d,s) + B_MASKx(p,1,d,s) +\ + B_MASKx(p,2,d,s) + B_MASKx(p,3,d,s) + B_MASKx(p,4,d,s) +\ + B_MASKx(p,5,d,s) + B_MASKx(p,6,d,s) + B_MASKx(p,7,d,s), d) + +#if PNG_USE_COMPILE_TIME_MASKS + /* Utility macros to construct all the masks for a depth/swap + * combination. The 's' parameter says whether the format is PNG + * (big endian bytes) or not. Only the three odd-numbered passes are + * required for the display/block algorithm. + */ +# define S_MASKS(d,s) { S_MASK(0,d,s), S_MASK(1,d,s), S_MASK(2,d,s),\ + S_MASK(3,d,s), S_MASK(4,d,s), S_MASK(5,d,s) } + +# define B_MASKS(d,s) { B_MASK(1,d,s), S_MASK(3,d,s), S_MASK(5,d,s) } + +# define DEPTH_INDEX(d) ((d)==1?0:((d)==2?1:2)) + + /* Hence the pre-compiled masks indexed by PACKSWAP (or not), depth and + * then pass: + */ + static PNG_CONST png_uint_32 row_mask[2/*PACKSWAP*/][3/*depth*/][6] = { - png_bytep sp = png_ptr->row_buf + 1; - png_bytep dp = row; - int s_inc, s_start, s_end; - int m = 0x80; - int shift; - png_uint_32 i; - png_uint_32 row_width = png_ptr->width; - -#ifdef PNG_READ_PACKSWAP_SUPPORTED + /* Little-endian byte masks for PACKSWAP */ + { S_MASKS(1,0), S_MASKS(2,0), S_MASKS(4,0) }, + /* Normal (big-endian byte) masks - PNG format */ + { S_MASKS(1,1), S_MASKS(2,1), S_MASKS(4,1) } + }; + + /* display_mask has only three entries for the odd passes, so index by + * pass>>1. + */ + static PNG_CONST png_uint_32 display_mask[2][3][3] = + { + /* Little-endian byte masks for PACKSWAP */ + { B_MASKS(1,0), B_MASKS(2,0), B_MASKS(4,0) }, + /* Normal (big-endian byte) masks - PNG format */ + { B_MASKS(1,1), B_MASKS(2,1), B_MASKS(4,1) } + }; + +# define MASK(pass,depth,display,png)\ + ((display)?display_mask[png][DEPTH_INDEX(depth)][pass>>1]:\ + row_mask[png][DEPTH_INDEX(depth)][pass]) + +#else /* !PNG_USE_COMPILE_TIME_MASKS */ + /* This is the runtime alternative: it seems unlikely that this will + * ever be either smaller or faster than the compile time approach. + */ +# define MASK(pass,depth,display,png)\ + ((display)?B_MASK(pass,depth,png):S_MASK(pass,depth,png)) +#endif /* !PNG_USE_COMPILE_TIME_MASKS */ + + /* Use the appropriate mask to copy the required bits. In some cases + * the byte mask will be 0 or 0xff, optimize these cases. row_width is + * the number of pixels, but the code copies bytes, so it is necessary + * to special case the end. + */ + png_uint_32 pixels_per_byte = 8 / pixel_depth; + png_uint_32 mask; + +# ifdef PNG_READ_PACKSWAP_SUPPORTED if (png_ptr->transformations & PNG_PACKSWAP) - { - s_start = 0; - s_end = 7; - s_inc = 1; - } + mask = MASK(pass, pixel_depth, display, 0); else -#endif +# endif + mask = MASK(pass, pixel_depth, display, 1); + + for (;;) + { + png_uint_32 m; + + /* It doesn't matter in the following if png_uint_32 has more than + * 32 bits because the high bits always match those in m<<24; it is, + * however, essential to use OR here, not +, because of this. + */ + m = mask; + mask = (m >> 8) | (m << 24); /* rotate right to good compilers */ + m &= 0xff; + + if (m != 0) /* something to copy */ { - s_start = 7; - s_end = 0; - s_inc = -1; + if (m != 0xff) + *dp = (png_byte)((*dp & ~m) | (*sp & m)); + else + *dp = *sp; } - shift = s_start; + /* NOTE: this may overwrite the last byte with garbage if the image + * is not an exact number of bytes wide; libpng has always done + * this. + */ + if (row_width <= pixels_per_byte) + break; /* May need to restore part of the last byte */ - for (i = 0; i < row_width; i++) - { - if (m & mask) - { - int value; + row_width -= pixels_per_byte; + ++dp; + ++sp; + } + } - value = (*sp >> shift) & 0x01; - *dp &= (png_byte)((0x7f7f >> (7 - shift)) & 0xff); - *dp |= (png_byte)(value << shift); - } + else /* pixel_depth >= 8 */ + { + unsigned int bytes_to_copy, bytes_to_jump; - if (shift == s_end) - { - shift = s_start; - sp++; - dp++; - } + /* Validate the depth - it must be a multiple of 8 */ + if (pixel_depth & 7) + png_error(png_ptr, "invalid user transform pixel depth"); - else - shift += s_inc; + pixel_depth >>= 3; /* now in bytes */ + row_width *= pixel_depth; - if (m == 1) - m = 0x80; + /* Regardless of pass number the Adam 7 interlace always results in a + * fixed number of pixels to copy then to skip. There may be a + * different number of pixels to skip at the start though. + */ + { + unsigned int offset = PNG_PASS_START_COL(pass) * pixel_depth; - else - m >>= 1; - } - break; + row_width -= offset; + dp += offset; + sp += offset; } - case 2: + /* Work out the bytes to copy. */ + if (display) { - png_bytep sp = png_ptr->row_buf + 1; - png_bytep dp = row; - int s_start, s_end, s_inc; - int m = 0x80; - int shift; - png_uint_32 i; - png_uint_32 row_width = png_ptr->width; - int value; + /* When doing the 'block' algorithm the pixel in the pass gets + * replicated to adjacent pixels. This is why the even (0,2,4,6) + * passes are skipped above - the entire expanded row is copied. + */ + bytes_to_copy = (1<<((6-pass)>>1)) * pixel_depth; -#ifdef PNG_READ_PACKSWAP_SUPPORTED - if (png_ptr->transformations & PNG_PACKSWAP) - { - s_start = 0; - s_end = 6; - s_inc = 2; - } + /* But don't allow this number to exceed the actual row width. */ + if (bytes_to_copy > row_width) + bytes_to_copy = row_width; + } - else -#endif - { - s_start = 6; - s_end = 0; - s_inc = -2; - } + else /* normal row; Adam7 only ever gives us one pixel to copy. */ + bytes_to_copy = pixel_depth; + + /* In Adam7 there is a constant offset between where the pixels go. */ + bytes_to_jump = PNG_PASS_COL_OFFSET(pass) * pixel_depth; + + /* And simply copy these bytes. Some optimization is possible here, + * depending on the value of 'bytes_to_copy'. Special case the low + * byte counts, which we know to be frequent. + * + * Notice that these cases all 'return' rather than 'break' - this + * avoids an unnecessary test on whether to restore the last byte + * below. + */ + switch (bytes_to_copy) + { + case 1: + for (;;) + { + *dp = *sp; - shift = s_start; + if (row_width <= bytes_to_jump) + return; - for (i = 0; i < row_width; i++) - { - if (m & mask) - { - value = (*sp >> shift) & 0x03; - *dp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff); - *dp |= (png_byte)(value << shift); + dp += bytes_to_jump; + sp += bytes_to_jump; + row_width -= bytes_to_jump; } - if (shift == s_end) + case 2: + /* There is a possibility of a partial copy at the end here; this + * slows the code down somewhat. + */ + do { - shift = s_start; - sp++; - dp++; - } + dp[0] = sp[0], dp[1] = sp[1]; - else - shift += s_inc; + if (row_width <= bytes_to_jump) + return; - if (m == 1) - m = 0x80; + sp += bytes_to_jump; + dp += bytes_to_jump; + row_width -= bytes_to_jump; + } + while (row_width > 1); - else - m >>= 1; - } - break; - } + /* And there can only be one byte left at this point: */ + *dp = *sp; + return; - case 4: - { - png_bytep sp = png_ptr->row_buf + 1; - png_bytep dp = row; - int s_start, s_end, s_inc; - int m = 0x80; - int shift; - png_uint_32 i; - png_uint_32 row_width = png_ptr->width; - int value; - -#ifdef PNG_READ_PACKSWAP_SUPPORTED - if (png_ptr->transformations & PNG_PACKSWAP) - { - s_start = 0; - s_end = 4; - s_inc = 4; - } + case 3: + /* This can only be the RGB case, so each copy is exactly one + * pixel and it is not necessary to check for a partial copy. + */ + for(;;) + { + dp[0] = sp[0], dp[1] = sp[1], dp[2] = sp[2]; - else -#endif - { - s_start = 4; - s_end = 0; - s_inc = -4; - } - shift = s_start; + if (row_width <= bytes_to_jump) + return; - for (i = 0; i < row_width; i++) - { - if (m & mask) - { - value = (*sp >> shift) & 0xf; - *dp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff); - *dp |= (png_byte)(value << shift); + sp += bytes_to_jump; + dp += bytes_to_jump; + row_width -= bytes_to_jump; } - if (shift == s_end) + default: +#if PNG_ALIGN_TYPE != PNG_ALIGN_NONE + /* Check for double byte alignment and, if possible, use a + * 16-bit copy. Don't attempt this for narrow images - ones that + * are less than an interlace panel wide. Don't attempt it for + * wide bytes_to_copy either - use the png_memcpy there. + */ + if (bytes_to_copy < 16 /*else use png_memcpy*/ && + png_isaligned(dp, png_uint_16) && + png_isaligned(sp, png_uint_16) && + bytes_to_copy % sizeof (png_uint_16) == 0 && + bytes_to_jump % sizeof (png_uint_16) == 0) { - shift = s_start; - sp++; - dp++; + /* Everything is aligned for png_uint_16 copies, but try for + * png_uint_32 first. + */ + if (png_isaligned(dp, png_uint_32) && + png_isaligned(sp, png_uint_32) && + bytes_to_copy % sizeof (png_uint_32) == 0 && + bytes_to_jump % sizeof (png_uint_32) == 0) + { + png_uint_32p dp32 = (png_uint_32p)dp; + png_const_uint_32p sp32 = (png_const_uint_32p)sp; + unsigned int skip = (bytes_to_jump-bytes_to_copy) / + sizeof (png_uint_32); + + do + { + size_t c = bytes_to_copy; + do + { + *dp32++ = *sp32++; + c -= sizeof (png_uint_32); + } + while (c > 0); + + if (row_width <= bytes_to_jump) + return; + + dp32 += skip; + sp32 += skip; + row_width -= bytes_to_jump; + } + while (bytes_to_copy <= row_width); + + /* Get to here when the row_width truncates the final copy. + * There will be 1-3 bytes left to copy, so don't try the + * 16-bit loop below. + */ + dp = (png_bytep)dp32; + sp = (png_const_bytep)sp32; + do + *dp++ = *sp++; + while (--row_width > 0); + return; + } + + /* Else do it in 16-bit quantities, but only if the size is + * not too large. + */ + else + { + png_uint_16p dp16 = (png_uint_16p)dp; + png_const_uint_16p sp16 = (png_const_uint_16p)sp; + unsigned int skip = (bytes_to_jump-bytes_to_copy) / + sizeof (png_uint_16); + + do + { + size_t c = bytes_to_copy; + do + { + *dp16++ = *sp16++; + c -= sizeof (png_uint_16); + } + while (c > 0); + + if (row_width <= bytes_to_jump) + return; + + dp16 += skip; + sp16 += skip; + row_width -= bytes_to_jump; + } + while (bytes_to_copy <= row_width); + + /* End of row - 1 byte left, bytes_to_copy > row_width: */ + dp = (png_bytep)dp16; + sp = (png_const_bytep)sp16; + do + *dp++ = *sp++; + while (--row_width > 0); + return; + } } +#endif /* PNG_ALIGN_ code */ - else - shift += s_inc; + /* The true default - use a png_memcpy: */ + for (;;) + { + png_memcpy(dp, sp, bytes_to_copy); - if (m == 1) - m = 0x80; + if (row_width <= bytes_to_jump) + return; - else - m >>= 1; - } - break; + sp += bytes_to_jump; + dp += bytes_to_jump; + row_width -= bytes_to_jump; + if (bytes_to_copy > row_width) + bytes_to_copy = row_width; + } } - default: - { - png_bytep sp = png_ptr->row_buf + 1; - png_bytep dp = row; - png_size_t pixel_bytes = (png_ptr->row_info.pixel_depth >> 3); - png_uint_32 i; - png_uint_32 row_width = png_ptr->width; - png_byte m = 0x80; - - for (i = 0; i < row_width; i++) - { - if (m & mask) - { - png_memcpy(dp, sp, pixel_bytes); - } + /* NOT REACHED*/ + } /* pixel_depth >= 8 */ - sp += pixel_bytes; - dp += pixel_bytes; + /* Here if pixel_depth < 8 to check 'end_ptr' below. */ + } + else +#endif - if (m == 1) - m = 0x80; + /* If here then the switch above wasn't used so just png_memcpy the whole row + * from the temporary row buffer (notice that this overwrites the end of the + * destination row if it is a partial byte.) + */ + png_memcpy(dp, sp, PNG_ROWBYTES(pixel_depth, row_width)); - else - m >>= 1; - } - break; - } - } - } + /* Restore the overwritten bits from the last byte if necessary. */ + if (end_ptr != NULL) + *end_ptr = (png_byte)((end_byte & end_mask) | (*end_ptr & ~end_mask)); } #ifdef PNG_READ_INTERLACING_SUPPORTED void /* PRIVATE */ -png_do_read_interlace(png_structp png_ptr) +png_do_read_interlace(png_row_infop row_info, png_bytep row, int pass, + png_uint_32 transformations /* Because these may affect the byte layout */) { - png_row_infop row_info = &(png_ptr->row_info); - png_bytep row = png_ptr->row_buf + 1; - int pass = png_ptr->pass; - png_uint_32 transformations = png_ptr->transformations; /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ /* Offset to next interlace block */ - PNG_CONST int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; + static PNG_CONST int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; png_debug(1, "in png_do_read_interlace"); if (row != NULL && row_info != NULL) @@ -3049,7 +3432,7 @@ png_do_read_interlace(png_structp png_ptr) for (i = 0; i < row_info->width; i++) { - png_byte v = (png_byte)((*sp >> sshift) & 0xf); + png_byte v = (png_byte)((*sp >> sshift) & 0x0f); int j; for (j = 0; j < jstop; j++) @@ -3078,6 +3461,7 @@ png_do_read_interlace(png_structp png_ptr) } break; } + default: { png_size_t pixel_bytes = (row_info->pixel_depth >> 3); @@ -3108,6 +3492,7 @@ png_do_read_interlace(png_structp png_ptr) break; } } + row_info->width = final_width; row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, final_width); } @@ -3117,132 +3502,252 @@ png_do_read_interlace(png_structp png_ptr) } #endif /* PNG_READ_INTERLACING_SUPPORTED */ -void /* PRIVATE */ -png_read_filter_row(png_structp png_ptr, png_row_infop row_info, png_bytep row, - png_const_bytep prev_row, int filter) +static void +png_read_filter_row_sub(png_row_infop row_info, png_bytep row, + png_const_bytep prev_row) { - png_debug(1, "in png_read_filter_row"); - png_debug2(2, "row = %u, filter = %d", png_ptr->row_number, filter); - switch (filter) + png_size_t i; + png_size_t istop = row_info->rowbytes; + unsigned int bpp = (row_info->pixel_depth + 7) >> 3; + png_bytep rp = row + bpp; + + PNG_UNUSED(prev_row) + + for (i = bpp; i < istop; i++) { - case PNG_FILTER_VALUE_NONE: - break; + *rp = (png_byte)(((int)(*rp) + (int)(*(rp-bpp))) & 0xff); + rp++; + } +} - case PNG_FILTER_VALUE_SUB: - { - png_size_t i; - png_size_t istop = row_info->rowbytes; - unsigned int bpp = (row_info->pixel_depth + 7) >> 3; - png_bytep rp = row + bpp; - png_bytep lp = row; +static void +png_read_filter_row_up(png_row_infop row_info, png_bytep row, + png_const_bytep prev_row) +{ + png_size_t i; + png_size_t istop = row_info->rowbytes; + png_bytep rp = row; + png_const_bytep pp = prev_row; - for (i = bpp; i < istop; i++) - { - *rp = (png_byte)(((int)(*rp) + (int)(*lp++)) & 0xff); - rp++; - } - break; - } - case PNG_FILTER_VALUE_UP: - { - png_size_t i; - png_size_t istop = row_info->rowbytes; - png_bytep rp = row; - png_const_bytep pp = prev_row; + for (i = 0; i < istop; i++) + { + *rp = (png_byte)(((int)(*rp) + (int)(*pp++)) & 0xff); + rp++; + } +} - for (i = 0; i < istop; i++) - { - *rp = (png_byte)(((int)(*rp) + (int)(*pp++)) & 0xff); - rp++; - } - break; - } - case PNG_FILTER_VALUE_AVG: - { - png_size_t i; - png_bytep rp = row; - png_const_bytep pp = prev_row; - png_bytep lp = row; - unsigned int bpp = (row_info->pixel_depth + 7) >> 3; - png_size_t istop = row_info->rowbytes - bpp; - - for (i = 0; i < bpp; i++) - { - *rp = (png_byte)(((int)(*rp) + - ((int)(*pp++) / 2 )) & 0xff); +static void +png_read_filter_row_avg(png_row_infop row_info, png_bytep row, + png_const_bytep prev_row) +{ + png_size_t i; + png_bytep rp = row; + png_const_bytep pp = prev_row; + unsigned int bpp = (row_info->pixel_depth + 7) >> 3; + png_size_t istop = row_info->rowbytes - bpp; - rp++; - } + for (i = 0; i < bpp; i++) + { + *rp = (png_byte)(((int)(*rp) + + ((int)(*pp++) / 2 )) & 0xff); - for (i = 0; i < istop; i++) - { - *rp = (png_byte)(((int)(*rp) + - (int)(*pp++ + *lp++) / 2 ) & 0xff); + rp++; + } - rp++; - } - break; - } - case PNG_FILTER_VALUE_PAETH: - { - png_size_t i; - png_bytep rp = row; - png_const_bytep pp = prev_row; - png_bytep lp = row; - png_const_bytep cp = prev_row; - unsigned int bpp = (row_info->pixel_depth + 7) >> 3; - png_size_t istop=row_info->rowbytes - bpp; - - for (i = 0; i < bpp; i++) - { - *rp = (png_byte)(((int)(*rp) + (int)(*pp++)) & 0xff); - rp++; - } + for (i = 0; i < istop; i++) + { + *rp = (png_byte)(((int)(*rp) + + (int)(*pp++ + *(rp-bpp)) / 2 ) & 0xff); - for (i = 0; i < istop; i++) /* Use leftover rp,pp */ - { - int a, b, c, pa, pb, pc, p; + rp++; + } +} - a = *lp++; - b = *pp++; - c = *cp++; +static void +png_read_filter_row_paeth_1byte_pixel(png_row_infop row_info, png_bytep row, + png_const_bytep prev_row) +{ + png_bytep rp_end = row + row_info->rowbytes; + int a, c; - p = b - c; - pc = a - c; + /* First pixel/byte */ + c = *prev_row++; + a = *row + c; + *row++ = (png_byte)a; -#ifdef PNG_USE_ABS - pa = abs(p); - pb = abs(pc); - pc = abs(p + pc); -#else - pa = p < 0 ? -p : p; - pb = pc < 0 ? -pc : pc; - pc = (p + pc) < 0 ? -(p + pc) : p + pc; -#endif + /* Remainder */ + while (row < rp_end) + { + int b, pa, pb, pc, p; - /* - if (pa <= pb && pa <= pc) - p = a; + a &= 0xff; /* From previous iteration or start */ + b = *prev_row++; - else if (pb <= pc) - p = b; + p = b - c; + pc = a - c; - else - p = c; - */ +# ifdef PNG_USE_ABS + pa = abs(p); + pb = abs(pc); + pc = abs(p + pc); +# else + pa = p < 0 ? -p : p; + pb = pc < 0 ? -pc : pc; + pc = (p + pc) < 0 ? -(p + pc) : p + pc; +# endif - p = (pa <= pb && pa <= pc) ? a : (pb <= pc) ? b : c; + /* Find the best predictor, the least of pa, pb, pc favoring the earlier + * ones in the case of a tie. + */ + if (pb < pa) pa = pb, a = b; + if (pc < pa) a = c; - *rp = (png_byte)(((int)(*rp) + p) & 0xff); - rp++; - } + /* Calculate the current pixel in a, and move the previous row pixel to c + * for the next time round the loop + */ + c = b; + a += *row; + *row++ = (png_byte)a; + } +} + +static void +png_read_filter_row_paeth_multibyte_pixel(png_row_infop row_info, png_bytep row, + png_const_bytep prev_row) +{ + int bpp = (row_info->pixel_depth + 7) >> 3; + png_bytep rp_end = row + bpp; + + /* Process the first pixel in the row completely (this is the same as 'up' + * because there is only one candidate predictor for the first row). + */ + while (row < rp_end) + { + int a = *row + *prev_row++; + *row++ = (png_byte)a; + } + + /* Remainder */ + rp_end += row_info->rowbytes - bpp; + + while (row < rp_end) + { + int a, b, c, pa, pb, pc, p; + + c = *(prev_row - bpp); + a = *(row - bpp); + b = *prev_row++; + + p = b - c; + pc = a - c; + +# ifdef PNG_USE_ABS + pa = abs(p); + pb = abs(pc); + pc = abs(p + pc); +# else + pa = p < 0 ? -p : p; + pb = pc < 0 ? -pc : pc; + pc = (p + pc) < 0 ? -(p + pc) : p + pc; +# endif + + if (pb < pa) pa = pb, a = b; + if (pc < pa) a = c; + + c = b; + a += *row; + *row++ = (png_byte)a; + } +} + +#ifdef PNG_ARM_NEON + +#ifdef __linux__ +#include <stdio.h> +#include <elf.h> +#include <asm/hwcap.h> + +static int png_have_hwcap(unsigned cap) +{ + FILE *f = fopen("/proc/self/auxv", "r"); + Elf32_auxv_t aux; + int have_cap = 0; + + if (!f) + return 0; + + while (fread(&aux, sizeof(aux), 1, f) > 0) + { + if (aux.a_type == AT_HWCAP && + aux.a_un.a_val & cap) + { + have_cap = 1; break; } - default: - png_error(png_ptr, "Ignoring bad adaptive filter type"); - /*NOT REACHED */ - break; } + + fclose(f); + + return have_cap; +} +#endif /* __linux__ */ + +static void +png_init_filter_functions_neon(png_structp pp, unsigned int bpp) +{ +#ifdef __linux__ + if (!png_have_hwcap(HWCAP_NEON)) + return; +#endif + + pp->read_filter[PNG_FILTER_VALUE_UP-1] = png_read_filter_row_up_neon; + + if (bpp == 3) + { + pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub3_neon; + pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg3_neon; + pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = + png_read_filter_row_paeth3_neon; + } + + else if (bpp == 4) + { + pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub4_neon; + pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg4_neon; + pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = + png_read_filter_row_paeth4_neon; + } +} +#endif /* PNG_ARM_NEON */ + +static void +png_init_filter_functions(png_structp pp) +{ + unsigned int bpp = (pp->pixel_depth + 7) >> 3; + + pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub; + pp->read_filter[PNG_FILTER_VALUE_UP-1] = png_read_filter_row_up; + pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg; + if (bpp == 1) + pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = + png_read_filter_row_paeth_1byte_pixel; + else + pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = + png_read_filter_row_paeth_multibyte_pixel; + +#ifdef PNG_ARM_NEON + png_init_filter_functions_neon(pp, bpp); +#endif +} + +void /* PRIVATE */ +png_read_filter_row(png_structp pp, png_row_infop row_info, png_bytep row, + png_const_bytep prev_row, int filter) +{ + if (pp->read_filter[0] == NULL) + png_init_filter_functions(pp); + if (filter > PNG_FILTER_VALUE_NONE && filter < PNG_FILTER_VALUE_LAST) + pp->read_filter[filter-1](row_info, row, prev_row); } #ifdef PNG_SEQUENTIAL_READ_SUPPORTED @@ -3253,16 +3758,16 @@ png_read_finish_row(png_structp png_ptr) /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ /* Start of interlace block */ - PNG_CONST int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; + static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; /* Offset to next interlace block */ - PNG_CONST int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; + static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; /* Start of interlace block in the y direction */ - PNG_CONST int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1}; + static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1}; /* Offset to next interlace block in the y direction */ - PNG_CONST int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; + static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; #endif /* PNG_READ_INTERLACING_SUPPORTED */ png_debug(1, "in png_read_finish_row"); @@ -3275,6 +3780,9 @@ png_read_finish_row(png_structp png_ptr) { png_ptr->row_number = 0; + /* TO DO: don't do this if prev_row isn't needed (requires + * read-ahead of the next row's filter byte. + */ png_memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1); do @@ -3309,7 +3817,6 @@ png_read_finish_row(png_structp png_ptr) if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED)) { - PNG_IDAT; char extra; int ret; @@ -3324,7 +3831,7 @@ png_read_finish_row(png_structp png_ptr) { png_crc_finish(png_ptr, 0); png_ptr->idat_size = png_read_chunk_header(png_ptr); - if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) + if (png_ptr->chunk_name != png_IDAT) png_error(png_ptr, "Not enough image data"); } @@ -3383,16 +3890,16 @@ png_read_start_row(png_structp png_ptr) /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ /* Start of interlace block */ - PNG_CONST int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; + static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; /* Offset to next interlace block */ - PNG_CONST int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; + static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; /* Start of interlace block in the y direction */ - PNG_CONST int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1}; + static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1}; /* Offset to next interlace block in the y direction */ - PNG_CONST int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; + static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; #endif int max_pixel_depth; @@ -3400,7 +3907,9 @@ png_read_start_row(png_structp png_ptr) png_debug(1, "in png_read_start_row"); png_ptr->zstream.avail_in = 0; +#ifdef PNG_READ_TRANSFORMS_SUPPORTED png_init_read_transformations(png_ptr); +#endif #ifdef PNG_READ_INTERLACING_SUPPORTED if (png_ptr->interlaced) { @@ -3426,6 +3935,16 @@ png_read_start_row(png_structp png_ptr) max_pixel_depth = png_ptr->pixel_depth; + /* WARNING: * png_read_transform_info (pngrtran.c) performs a simpliar set of + * calculations to calculate the final pixel depth, then + * png_do_read_transforms actually does the transforms. This means that the + * code which effectively calculates this value is actually repeated in three + * separate places. They must all match. Innocent changes to the order of + * transformations can and will break libpng in a way that causes memory + * overwrites. + * + * TODO: fix this. + */ #ifdef PNG_READ_PACK_SUPPORTED if ((png_ptr->transformations & PNG_PACK) && png_ptr->bit_depth < 8) max_pixel_depth = 8; @@ -3463,13 +3982,28 @@ png_read_start_row(png_structp png_ptr) } #endif +#ifdef PNG_READ_EXPAND_16_SUPPORTED + if (png_ptr->transformations & PNG_EXPAND_16) + { +# ifdef PNG_READ_EXPAND_SUPPORTED + /* In fact it is an error if it isn't supported, but checking is + * the safe way. + */ + if (png_ptr->transformations & PNG_EXPAND) + { + if (png_ptr->bit_depth < 16) + max_pixel_depth *= 2; + } + else +# endif + png_ptr->transformations &= ~PNG_EXPAND_16; + } +#endif + #ifdef PNG_READ_FILLER_SUPPORTED if (png_ptr->transformations & (PNG_FILLER)) { - if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) - max_pixel_depth = 32; - - else if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY) + if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY) { if (max_pixel_depth <= 8) max_pixel_depth = 16; @@ -3478,7 +4012,8 @@ png_read_start_row(png_structp png_ptr) max_pixel_depth = 32; } - else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB) + else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB || + png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) { if (max_pixel_depth <= 32) max_pixel_depth = 32; @@ -3532,14 +4067,20 @@ png_read_start_row(png_structp png_ptr) defined(PNG_USER_TRANSFORM_PTR_SUPPORTED) if (png_ptr->transformations & PNG_USER_TRANSFORM) { - int user_pixel_depth = png_ptr->user_transform_depth* + int user_pixel_depth = png_ptr->user_transform_depth * png_ptr->user_transform_channels; if (user_pixel_depth > max_pixel_depth) - max_pixel_depth=user_pixel_depth; + max_pixel_depth = user_pixel_depth; } #endif + /* This value is stored in png_struct and double checked in the row read + * code. + */ + png_ptr->maximum_pixel_depth = (png_byte)max_pixel_depth; + png_ptr->transformed_pixel_depth = 0; /* calculated on demand */ + /* Align the width on the next larger 8 pixels. Mainly used * for interlacing */ @@ -3558,28 +4099,39 @@ defined(PNG_USER_TRANSFORM_PTR_SUPPORTED) if (row_bytes + 48 > png_ptr->old_big_row_buf_size) { png_free(png_ptr, png_ptr->big_row_buf); + png_free(png_ptr, png_ptr->big_prev_row); if (png_ptr->interlaced) png_ptr->big_row_buf = (png_bytep)png_calloc(png_ptr, row_bytes + 48); else - png_ptr->big_row_buf = (png_bytep)png_malloc(png_ptr, - row_bytes + 48); + png_ptr->big_row_buf = (png_bytep)png_malloc(png_ptr, row_bytes + 48); - png_ptr->old_big_row_buf_size = row_bytes + 48; + png_ptr->big_prev_row = (png_bytep)png_malloc(png_ptr, row_bytes + 48); #ifdef PNG_ALIGNED_MEMORY_SUPPORTED /* Use 16-byte aligned memory for row_buf with at least 16 bytes - * of padding before and after row_buf. + * of padding before and after row_buf; treat prev_row similarly. + * NOTE: the alignment is to the start of the pixels, one beyond the start + * of the buffer, because of the filter byte. Prior to libpng 1.5.6 this + * was incorrect; the filter byte was aligned, which had the exact + * opposite effect of that intended. */ - png_ptr->row_buf = png_ptr->big_row_buf + 32 - - (((png_alloc_size_t)png_ptr->big_row_buf + 15) & 0x0F); + { + png_bytep temp = png_ptr->big_row_buf + 32; + int extra = (int)((temp - (png_bytep)0) & 0x0f); + png_ptr->row_buf = temp - extra - 1/*filter byte*/; + + temp = png_ptr->big_prev_row + 32; + extra = (int)((temp - (png_bytep)0) & 0x0f); + png_ptr->prev_row = temp - extra - 1/*filter byte*/; + } - png_ptr->old_big_row_buf_size = row_bytes + 48; #else - /* Use 32 bytes of padding before and 16 bytes after row_buf. */ - png_ptr->row_buf = png_ptr->big_row_buf + 32; + /* 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; } @@ -3592,15 +4144,6 @@ defined(PNG_USER_TRANSFORM_PTR_SUPPORTED) if (png_ptr->rowbytes > (PNG_SIZE_MAX - 1)) png_error(png_ptr, "Row has too many bytes to allocate in memory"); - if (png_ptr->rowbytes + 1 > png_ptr->old_prev_row_size) - { - png_free(png_ptr, png_ptr->prev_row); - - png_ptr->prev_row = (png_bytep)png_malloc(png_ptr, png_ptr->rowbytes + 1); - - png_ptr->old_prev_row_size = png_ptr->rowbytes + 1; - } - png_memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1); png_debug1(3, "width = %u,", png_ptr->width); |