/* pngrutil.c - utilities to read a PNG file * * libpng 1.0.7beta16 - June 4, 2000 * For conditions of distribution and use, see copyright notice in png.h * Copyright (c) 1998, 1999, 2000 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.) * * This file contains routines that are only called from within * libpng itself during the course of reading an image. */ #define PNG_INTERNAL #include "png.h" #ifndef PNG_READ_BIG_ENDIAN_SUPPORTED /* Grab an unsigned 32-bit integer from a buffer in big-endian format. */ png_uint_32 /* PRIVATE */ png_get_uint_32(png_bytep buf) { png_uint_32 i = ((png_uint_32)(*buf) << 24) + ((png_uint_32)(*(buf + 1)) << 16) + ((png_uint_32)(*(buf + 2)) << 8) + (png_uint_32)(*(buf + 3)); return (i); } #if defined(PNG_READ_pCAL_SUPPORTED) || defined(PNG_READ_oFFs_SUPPORTED) /* Grab a signed 32-bit integer from a buffer in big-endian format. The * data is stored in the PNG file in two's complement format, and it is * assumed that the machine format for signed integers is the same. */ png_int_32 /* PRIVATE */ png_get_int_32(png_bytep buf) { png_int_32 i = ((png_int_32)(*buf) << 24) + ((png_int_32)(*(buf + 1)) << 16) + ((png_int_32)(*(buf + 2)) << 8) + (png_int_32)(*(buf + 3)); return (i); } #endif /* PNG_READ_pCAL_SUPPORTED */ /* Grab an unsigned 16-bit integer from a buffer in big-endian format. */ png_uint_16 /* PRIVATE */ png_get_uint_16(png_bytep buf) { png_uint_16 i = (png_uint_16)(((png_uint_16)(*buf) << 8) + (png_uint_16)(*(buf + 1))); return (i); } #endif /* PNG_READ_BIG_ENDIAN_SUPPORTED */ /* Read data, and (optionally) run it through the CRC. */ void /* PRIVATE */ png_crc_read(png_structp png_ptr, png_bytep buf, png_size_t length) { png_read_data(png_ptr, buf, length); png_calculate_crc(png_ptr, buf, length); } /* Optionally skip data and then check the CRC. Depending on whether we are reading a ancillary or critical chunk, and how the program has set things up, we may calculate the CRC on the data and print a message. Returns '1' if there was a CRC error, '0' otherwise. */ int /* PRIVATE */ png_crc_finish(png_structp png_ptr, png_uint_32 skip) { png_size_t i; png_size_t istop = png_ptr->zbuf_size; for (i = (png_size_t)skip; i > istop; i -= istop) { png_crc_read(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size); } if (i) { png_crc_read(png_ptr, png_ptr->zbuf, i); } 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))) { png_chunk_warning(png_ptr, "CRC error"); } else { png_chunk_error(png_ptr, "CRC error"); } return (1); } return (0); } /* Compare the CRC stored in the PNG file with that calculated by libpng from the data it has read thus far. */ int /* PRIVATE */ png_crc_error(png_structp png_ptr) { png_byte crc_bytes[4]; png_uint_32 crc; int need_crc = 1; if (png_ptr->chunk_name[0] & 0x20) /* ancillary */ { if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_MASK) == (PNG_FLAG_CRC_ANCILLARY_USE | PNG_FLAG_CRC_ANCILLARY_NOWARN)) need_crc = 0; } else /* critical */ { if (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_IGNORE) need_crc = 0; } png_read_data(png_ptr, crc_bytes, 4); if (need_crc) { crc = png_get_uint_32(crc_bytes); return ((int)(crc != png_ptr->crc)); } else return (0); } #if defined(PNG_READ_zTXt_SUPPORTED) || defined(PNG_READ_iTXt_SUPPORTED) || \ defined(PNG_READ_iCCP_SUPPORTED) /* * Decompress trailing data in a chunk. The assumption is that chunkdata * points at an allocated area holding the contents of a chunk with a * trailing compressed part. What we get back is an allocated area * holding the original prefix part and an uncompressed version of the * trailing part (the malloc area passed in is freed). */ png_charp /* PRIVATE */ png_decompress_chunk(png_structp png_ptr, int comp_type, png_charp chunkdata, png_size_t chunklength, png_size_t prefix_size, png_size_t *newlength) { static char msg[] = "Error decoding compressed text"; png_charp text = NULL; png_size_t text_size; if (comp_type == PNG_TEXT_COMPRESSION_zTXt) { int ret = Z_OK; png_ptr->zstream.next_in = (png_bytep)(chunkdata + prefix_size); png_ptr->zstream.avail_in = (uInt)(chunklength - prefix_size); png_ptr->zstream.next_out = png_ptr->zbuf; png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; text_size = 0; text = NULL; while (png_ptr->zstream.avail_in) { ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH); if (ret != Z_OK && ret != Z_STREAM_END) { if (png_ptr->zstream.msg != NULL) png_warning(png_ptr, png_ptr->zstream.msg); else png_warning(png_ptr, msg); inflateReset(&png_ptr->zstream); png_ptr->zstream.avail_in = 0; if (text == NULL) { text_size = prefix_size + sizeof(msg) + 1; text = (png_charp)png_malloc(png_ptr, text_size); png_memcpy(text, chunkdata, prefix_size); } text[text_size - 1] = 0x00; /* Copy what we can of the error message into the text chunk */ text_size = (png_size_t)(chunklength - (text - chunkdata) - 1); text_size = sizeof(msg) > text_size ? text_size : sizeof(msg); png_memcpy(text + prefix_size, msg, text_size + 1); break; } if (!png_ptr->zstream.avail_out || ret == Z_STREAM_END) { if (text == NULL) { text_size = prefix_size + png_ptr->zbuf_size - png_ptr->zstream.avail_out; text = (png_charp)png_malloc(png_ptr, text_size + 1); png_memcpy(text + prefix_size, png_ptr->zbuf, text_size - prefix_size); png_memcpy(text, chunkdata, prefix_size); *(text + text_size) = 0x00; } else { png_charp tmp; tmp = text; text = (png_charp)png_malloc(png_ptr, (png_uint_32)(text_size + png_ptr->zbuf_size - png_ptr->zstream.avail_out + 1)); png_memcpy(text, tmp, text_size); png_free(png_ptr, tmp); png_memcpy(text + text_size, png_ptr->zbuf, (png_ptr->zbuf_size - png_ptr->zstream.avail_out)); text_size += png_ptr->zbuf_size - png_ptr->zstream.avail_out; *(text + text_size) = 0x00; } if (ret == Z_STREAM_END) break; else { png_ptr->zstream.next_out = png_ptr->zbuf; png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; } } } if (ret != Z_STREAM_END) png_warning(png_ptr, "End of datastream not found in a compressed chunk (other than IDAT)"); inflateReset(&png_ptr->zstream); png_ptr->zstream.avail_in = 0; png_free(png_ptr, chunkdata); chunkdata = text; *newlength=text_size; } else /* if (comp_type >= PNG_TEXT_COMPRESSION_LAST) */ { #if !defined(PNG_NO_STDIO) char umsg[50]; sprintf(umsg, "Unknown zTXt compression type %d", comp_type); png_warning(png_ptr, umsg); #else png_warning(png_ptr, "Unknown zTXt compression type"); #endif /* Copy what we can of the error message into the text chunk */ text_size = (png_size_t)(chunklength - (text - chunkdata)); text_size = sizeof(msg) > text_size ? text_size : sizeof(msg); png_memcpy(text, msg, text_size); } return chunkdata; } #endif /* read and check the IDHR chunk */ void /* PRIVATE */ png_handle_IHDR(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) { png_byte buf[13]; png_uint_32 width, height; int bit_depth, color_type, compression_type, filter_type; int interlace_type; png_debug(1, "in png_handle_IHDR\n"); if (png_ptr->mode & PNG_HAVE_IHDR) png_error(png_ptr, "Out of place IHDR"); /* check the length */ if (length != 13) png_error(png_ptr, "Invalid IHDR chunk"); png_ptr->mode |= PNG_HAVE_IHDR; png_crc_read(png_ptr, buf, 13); png_crc_finish(png_ptr, 0); width = png_get_uint_32(buf); height = png_get_uint_32(buf + 4); bit_depth = buf[8]; color_type = buf[9]; compression_type = buf[10]; filter_type = buf[11]; interlace_type = buf[12]; /* check for width and height valid values */ if (width == 0 || width > PNG_MAX_UINT || height == 0 || height > PNG_MAX_UINT) png_error(png_ptr, "Invalid image size in IHDR"); /* check other values */ if (bit_depth != 1 && bit_depth != 2 && bit_depth != 4 && bit_depth != 8 && bit_depth != 16) png_error(png_ptr, "Invalid bit depth in IHDR"); if (color_type < 0 || color_type == 1 || color_type == 5 || color_type > 6) png_error(png_ptr, "Invalid color type in IHDR"); if (((color_type == PNG_COLOR_TYPE_PALETTE) && bit_depth > 8) || ((color_type == PNG_COLOR_TYPE_RGB || color_type == PNG_COLOR_TYPE_GRAY_ALPHA || color_type == PNG_COLOR_TYPE_RGB_ALPHA) && bit_depth < 8)) png_error(png_ptr, "Invalid color type/bit depth combination in IHDR"); if (interlace_type >= PNG_INTERLACE_LAST) png_error(png_ptr, "Unknown interlace method in IHDR"); if (compression_type != PNG_COMPRESSION_TYPE_BASE) png_error(png_ptr, "Unknown compression method in IHDR"); if (filter_type != PNG_FILTER_TYPE_BASE) png_error(png_ptr, "Unknown filter method in IHDR"); /* set internal variables */ png_ptr->width = width; png_ptr->height = height; png_ptr->bit_depth = (png_byte)bit_depth; png_ptr->interlaced = (png_byte)interlace_type; png_ptr->color_type = (png_byte)color_type; /* find number of channels */ switch (png_ptr->color_type) { case PNG_COLOR_TYPE_GRAY: case PNG_COLOR_TYPE_PALETTE: png_ptr->channels = 1; break; case PNG_COLOR_TYPE_RGB: png_ptr->channels = 3; break; case PNG_COLOR_TYPE_GRAY_ALPHA: png_ptr->channels = 2; break; case PNG_COLOR_TYPE_RGB_ALPHA: png_ptr->channels = 4; break; } /* set up other useful info */ png_ptr->pixel_depth = (png_byte)(png_ptr->bit_depth * png_ptr->channels); png_ptr->rowbytes = ((png_ptr->width * (png_uint_32)png_ptr->pixel_depth + 7) >> 3); png_debug1(3,"bit_depth = %d\n", png_ptr->bit_depth); png_debug1(3,"channels = %d\n", png_ptr->channels); png_debug1(3,"rowbytes = %d\n", png_ptr->rowbytes); png_set_IHDR(png_ptr, info_ptr, width, height, bit_depth, color_type, interlace_type, compression_type, filter_type); } /* read and check the palette */ void /* PRIVATE */ png_handle_PLTE(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) { png_colorp palette; int num, i; #ifndef PNG_NO_POINTER_INDEXING png_colorp pal_ptr; #endif png_debug(1, "in png_handle_PLTE\n"); if (!(png_ptr->mode & PNG_HAVE_IHDR)) png_error(png_ptr, "Missing IHDR before PLTE"); else if (png_ptr->mode & PNG_HAVE_IDAT) { png_warning(png_ptr, "Invalid PLTE after IDAT"); png_crc_finish(png_ptr, length); return; } else if (png_ptr->mode & PNG_HAVE_PLTE) png_error(png_ptr, "Duplicate PLTE chunk"); png_ptr->mode |= PNG_HAVE_PLTE; #if !defined(PNG_READ_OPT_PLTE_SUPPORTED) if (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE) { png_crc_finish(png_ptr, length); return; } #endif if (length > 768 || length % 3) { if (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE) { png_warning(png_ptr, "Invalid palette chunk"); png_crc_finish(png_ptr, length); return; } else { png_error(png_ptr, "Invalid palette chunk"); } } num = (int)length / 3; palette = (png_colorp)png_zalloc(png_ptr, (uInt)num, sizeof (png_color)); #ifndef PNG_NO_POINTER_INDEXING for (i = 0, pal_ptr = palette; i < num; i++, pal_ptr++) { png_byte buf[3]; png_crc_read(png_ptr, buf, 3); pal_ptr->red = buf[0]; pal_ptr->green = buf[1]; pal_ptr->blue = buf[2]; } #else for (i = 0; i < num; i++) { png_byte buf[3]; png_crc_read(png_ptr, buf, 3); /* don't depend upon png_color being any order */ palette[i].red = buf[0]; palette[i].green = buf[1]; palette[i].blue = buf[2]; } #endif /* If we actually NEED the PLTE chunk (ie for a paletted image), we do whatever the normal CRC configuration tells us. However, if we have an RGB image, the PLTE can be considered ancillary, so we will act as though it is. */ #if !defined(PNG_READ_OPT_PLTE_SUPPORTED) if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) #endif { png_crc_finish(png_ptr, 0); } #if !defined(PNG_READ_OPT_PLTE_SUPPORTED) else if (png_crc_error(png_ptr)) /* Only if we have a CRC error */ { /* If we don't want to use the data from an ancillary chunk, we have two options: an error abort, or a warning and we ignore the data in this chunk (which should be OK, since it's considered ancillary for a RGB or RGBA image). */ if (!(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_USE)) { if (png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN) { png_chunk_error(png_ptr, "CRC error"); } else { png_chunk_warning(png_ptr, "CRC error"); png_zfree(png_ptr, palette); return; } } /* Otherwise, we (optionally) emit a warning and use the chunk. */ else if (!(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN)) { png_chunk_warning(png_ptr, "CRC error"); } } #endif png_ptr->palette = palette; png_ptr->num_palette = (png_uint_16)num; #ifdef PNG_FREE_ME_SUPPORTED png_free_data(png_ptr, info_ptr, PNG_FREE_PLTE, 0); png_ptr->free_me |= PNG_FREE_PLTE; #else png_ptr->flags |= PNG_FLAG_FREE_PLTE; #endif png_set_PLTE(png_ptr, info_ptr, palette, num); #if defined(PNG_READ_tRNS_SUPPORTED) if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) { if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS)) { if (png_ptr->num_trans > (png_uint_16)num) { png_warning(png_ptr, "Truncating incorrect tRNS chunk length"); png_ptr->num_trans = (png_uint_16)num; } if (info_ptr->num_trans > (png_uint_16)num) { png_warning(png_ptr, "Truncating incorrect info tRNS chunk length"); info_ptr->num_trans = (png_uint_16)num; } } } #endif } void /* PRIVATE */ png_handle_IEND(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) { png_debug(1, "in png_handle_IEND\n"); if (!(png_ptr->mode & PNG_HAVE_IHDR) || !(png_ptr->mode & PNG_HAVE_IDAT)) { png_error(png_ptr, "No image in file"); /* to quiet compiler warnings about unused info_ptr */ if (info_ptr == NULL) return; } png_ptr->mode |= (PNG_AFTER_IDAT | PNG_HAVE_IEND); if (length != 0) { png_warning(png_ptr, "Incorrect IEND chunk length"); } png_crc_finish(png_ptr, length); } #if defined(PNG_READ_gAMA_SUPPORTED) void /* PRIVATE */ png_handle_gAMA(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) { png_fixed_point igamma; #ifdef PNG_FLOATING_POINT_SUPPORTED float file_gamma; #endif png_byte buf[4]; png_debug(1, "in png_handle_gAMA\n"); if (!(png_ptr->mode & PNG_HAVE_IHDR)) png_error(png_ptr, "Missing IHDR before gAMA"); else if (png_ptr->mode & PNG_HAVE_IDAT) { png_warning(png_ptr, "Invalid gAMA after IDAT"); png_crc_finish(png_ptr, length); return; } else if (png_ptr->mode & PNG_HAVE_PLTE) /* Should be an error, but we can cope with it */ png_warning(png_ptr, "Out of place gAMA chunk"); else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_gAMA) #if defined(PNG_READ_sRGB_SUPPORTED) && !(info_ptr->valid & PNG_INFO_sRGB) #endif ) { png_warning(png_ptr, "Duplicate gAMA chunk"); png_crc_finish(png_ptr, length); return; } if (length != 4) { png_warning(png_ptr, "Incorrect gAMA chunk length"); png_crc_finish(png_ptr, length); return; } png_crc_read(png_ptr, buf, 4); if (png_crc_finish(png_ptr, 0)) return; igamma = (png_fixed_point)png_get_uint_32(buf); /* check for zero gamma */ if (igamma == 0) return; #if defined(PNG_READ_sRGB_SUPPORTED) if (info_ptr->valid & PNG_INFO_sRGB) if(igamma < 45000L || igamma > 46000L) { png_warning(png_ptr, "Ignoring incorrect gAMA value when sRGB is also present"); #ifndef PNG_NO_STDIO fprintf(stderr, "gamma = (%d/100000)\n", (int)igamma); #endif return; } #endif /* PNG_READ_sRGB_SUPPORTED */ #ifdef PNG_FLOATING_POINT_SUPPORTED file_gamma = (float)igamma / (float)100000.0; # ifdef PNG_READ_GAMMA_SUPPORTED png_ptr->gamma = file_gamma; # endif png_set_gAMA(png_ptr, info_ptr, file_gamma); #endif #ifdef PNG_FIXED_POINT_SUPPORTED png_set_gAMA_fixed(png_ptr, info_ptr, igamma); #endif } #endif #if defined(PNG_READ_sBIT_SUPPORTED) void /* PRIVATE */ png_handle_sBIT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) { png_size_t truelen; png_byte buf[4]; png_debug(1, "in png_handle_sBIT\n"); buf[0] = buf[1] = buf[2] = buf[3] = 0; if (!(png_ptr->mode & PNG_HAVE_IHDR)) png_error(png_ptr, "Missing IHDR before sBIT"); else if (png_ptr->mode & PNG_HAVE_IDAT) { png_warning(png_ptr, "Invalid sBIT after IDAT"); png_crc_finish(png_ptr, length); return; } else if (png_ptr->mode & PNG_HAVE_PLTE) { /* Should be an error, but we can cope with it */ png_warning(png_ptr, "Out of place sBIT chunk"); } else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sBIT)) { png_warning(png_ptr, "Duplicate sBIT chunk"); png_crc_finish(png_ptr, length); return; } if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) truelen = 3; else truelen = (png_size_t)png_ptr->channels; if (length != truelen) { png_warning(png_ptr, "Incorrect sBIT chunk length"); png_crc_finish(png_ptr, length); return; } png_crc_read(png_ptr, buf, truelen); if (png_crc_finish(png_ptr, 0)) return; if (png_ptr->color_type & PNG_COLOR_MASK_COLOR) { png_ptr->sig_bit.red = buf[0]; png_ptr->sig_bit.green = buf[1]; png_ptr->sig_bit.blue = buf[2]; png_ptr->sig_bit.alpha = buf[3]; } else { png_ptr->sig_bit.gray = buf[0]; png_ptr->sig_bit.red = buf[0]; png_ptr->sig_bit.green = buf[0]; png_ptr->sig_bit.blue = buf[0]; png_ptr->sig_bit.alpha = buf[1]; } png_set_sBIT(png_ptr, info_ptr, &(png_ptr->sig_bit)); } #endif #if defined(PNG_READ_cHRM_SUPPORTED) void /* PRIVATE */ png_handle_cHRM(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) { png_byte buf[4]; #ifdef PNG_FLOATING_POINT_SUPPORTED float white_x, white_y, red_x, red_y, green_x, green_y, blue_x, blue_y; #endif png_fixed_point int_x_white, int_y_white, int_x_red, int_y_red, int_x_green, int_y_green, int_x_blue, int_y_blue; png_debug(1, "in png_handle_cHRM\n"); if (!(png_ptr->mode & PNG_HAVE_IHDR)) png_error(png_ptr, "Missing IHDR before cHRM"); else if (png_ptr->mode & PNG_HAVE_IDAT) { png_warning(png_ptr, "Invalid cHRM after IDAT"); png_crc_finish(png_ptr, length); return; } 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"); else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM) #if defined(PNG_READ_sRGB_SUPPORTED) && !(info_ptr->valid & PNG_INFO_sRGB) #endif ) { png_warning(png_ptr, "Duplicate cHRM chunk"); png_crc_finish(png_ptr, length); return; } if (length != 32) { png_warning(png_ptr, "Incorrect cHRM chunk length"); png_crc_finish(png_ptr, length); return; } png_crc_read(png_ptr, buf, 4); int_x_white = (png_fixed_point)png_get_uint_32(buf); png_crc_read(png_ptr, buf, 4); int_y_white = (png_fixed_point)png_get_uint_32(buf); if (int_x_white > 80000L || int_y_white > 80000L || int_x_white + int_y_white > 100000L) { png_warning(png_ptr, "Invalid cHRM white point"); png_crc_finish(png_ptr, 24); return; } png_crc_read(png_ptr, buf, 4); int_x_red = (png_fixed_point)png_get_uint_32(buf); png_crc_read(png_ptr, buf, 4); int_y_red = (png_fixed_point)png_get_uint_32(buf); if (int_x_red > 80000L || int_y_red > 80000L || int_x_red + int_y_red > 100000L) { png_warning(png_ptr, "Invalid cHRM red point"); png_crc_finish(png_ptr, 16); return; } png_crc_read(png_ptr, buf, 4); int_x_green = (png_fixed_point)png_get_uint_32(buf); png_crc_read(png_ptr, buf, 4); int_y_green = (png_fixed_point)png_get_uint_32(buf); if (int_x_green > 80000L || int_y_green > 80000L || int_x_green + int_y_green > 100000L) { png_warning(png_ptr, "Invalid cHRM green point"); png_crc_finish(png_ptr, 8); return; } png_crc_read(png_ptr, buf, 4); int_x_blue = (png_fixed_point)png_get_uint_32(buf); png_crc_read(png_ptr, buf, 4); int_y_blue = (png_fixed_point)png_get_uint_32(buf); if (int_x_blue > 80000L || int_y_blue > 80000L || int_x_blue + int_y_blue > 100000L) { png_warning(png_ptr, "Invalid cHRM blue point"); png_crc_finish(png_ptr, 0); return; } #ifdef PNG_FLOATING_POINT_SUPPORTED white_x = (float)int_x_white / (float)100000.0; white_y = (float)int_y_white / (float)100000.0; red_x = (float)int_x_red / (float)100000.0; red_y = (float)int_y_red / (float)100000.0; green_x = (float)int_x_green / (float)100000.0; green_y = (float)int_y_green / (float)100000.0; blue_x = (float)int_x_blue / (float)100000.0; blue_y = (float)int_y_blue / (float)100000.0; #endif #if defined(PNG_READ_sRGB_SUPPORTED) if (info_ptr->valid & PNG_INFO_sRGB) { if (abs(int_x_white - 31270L) > 1000 || abs(int_y_white - 32900L) > 1000 || abs( int_x_red - 64000L) > 1000 || abs( int_y_red - 33000L) > 1000 || abs(int_x_green - 30000L) > 1000 || abs(int_y_green - 60000L) > 1000 || abs( int_x_blue - 15000L) > 1000 || abs( int_y_blue - 6000L) > 1000) { png_warning(png_ptr, "Ignoring incorrect cHRM value when sRGB is also present"); #ifndef PNG_NO_STDIO #ifdef PNG_FLOATING_POINT_SUPPORTED fprintf(stderr,"wx=%f, wy=%f, rx=%f, ry=%f\n", white_x, white_y, red_x, red_y); fprintf(stderr,"gx=%f, gy=%f, bx=%f, by=%f\n", green_x, green_y, blue_x, blue_y); #else fprintf(stderr,"wx=%ld, wy=%ld, rx=%ld, ry=%ld\n", int_x_white, int_y_white, int_x_red, int_y_red); fprintf(stderr,"gx=%ld, gy=%ld, bx=%ld, by=%ld\n", int_x_green, int_y_green, int_x_blue, int_y_blue); #endif #endif /* PNG_NO_STDIO */ } png_crc_finish(png_ptr, 0); return; } #endif /* PNG_READ_sRGB_SUPPORTED */ #ifdef PNG_FLOATING_POINT_SUPPORTED png_set_cHRM(png_ptr, info_ptr, white_x, white_y, red_x, red_y, green_x, green_y, blue_x, blue_y); #endif #ifdef PNG_FIXED_POINT_SUPPORTED png_set_cHRM_fixed(png_ptr, info_ptr, int_x_white, int_y_white, int_x_red, int_y_red, int_x_green, int_y_green, int_x_blue, int_y_blue); #endif if (png_crc_finish(png_ptr, 0)) return; } #endif #if defined(PNG_READ_sRGB_SUPPORTED) void /* PRIVATE */ png_handle_sRGB(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) { int intent; png_byte buf[1]; png_debug(1, "in png_handle_sRGB\n"); if (!(png_ptr->mode & PNG_HAVE_IHDR)) png_error(png_ptr, "Missing IHDR before sRGB"); else if (png_ptr->mode & PNG_HAVE_IDAT) { png_warning(png_ptr, "Invalid sRGB after IDAT"); png_crc_finish(png_ptr, length); return; } else if (png_ptr->mode & PNG_HAVE_PLTE) /* Should be an error, but we can cope with it */ png_warning(png_ptr, "Out of place sRGB chunk"); else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sRGB)) { png_warning(png_ptr, "Duplicate sRGB chunk"); png_crc_finish(png_ptr, length); return; } if (length != 1) { png_warning(png_ptr, "Incorrect sRGB chunk length"); png_crc_finish(png_ptr, length); return; } png_crc_read(png_ptr, buf, 1); if (png_crc_finish(png_ptr, 0)) return; intent = buf[0]; /* check for bad intent */ if (intent >= PNG_sRGB_INTENT_LAST) { png_warning(png_ptr, "Unknown sRGB intent"); return; } #if defined(PNG_READ_gAMA_SUPPORTED) && defined(PNG_READ_GAMMA_SUPPORTED) if ((info_ptr->valid & PNG_INFO_gAMA)) { int igamma; #ifdef PNG_FIXED_POINT_SUPPORTED igamma=(int)info_ptr->int_gamma; #else # ifdef PNG_FLOATING_POINT_SUPPORTED igamma=(int)(info_ptr->gamma * 100000.); # endif #endif #if 0 && defined(PNG_cHRM_SUPPORTED) && !defined(PNG_FIXED_POINT_SUPPORTED) /* We need to define these here because they aren't in png.h */ png_fixed_point int_x_white; png_fixed_point int_y_white; png_fixed_point int_x_red; png_fixed_point int_y_red; png_fixed_point int_x_green; png_fixed_point int_y_green; png_fixed_point int_x_blue; png_fixed_point int_y_blue; #endif if(igamma < 45000L || igamma > 46000L) { png_warning(png_ptr, "Ignoring incorrect gAMA value when sRGB is also present"); #ifndef PNG_NO_STDIO # ifdef PNG_FIXED_POINT_SUPPORTED fprintf(stderr,"incorrect gamma=(%d/100000)\n",(int)png_ptr->int_gamma); # else # ifdef PNG_FLOATING_POINT_SUPPORTED fprintf(stderr,"incorrect gamma=%f\n",png_ptr->gamma); # endif # endif #endif } } #endif /* PNG_READ_gAMA_SUPPORTED */ #ifdef PNG_READ_cHRM_SUPPORTED #ifdef PNG_FIXED_POINT_SUPPORTED if (info_ptr->valid & PNG_INFO_cHRM) if (abs(info_ptr->int_x_white - 31270L) > 1000 || abs(info_ptr->int_y_white - 32900L) > 1000 || abs( info_ptr->int_x_red - 64000L) > 1000 || abs( info_ptr->int_y_red - 33000L) > 1000 || abs(info_ptr->int_x_green - 30000L) > 1000 || abs(info_ptr->int_y_green - 60000L) > 1000 || abs( info_ptr->int_x_blue - 15000L) > 1000 || abs( info_ptr->int_y_blue - 6000L) > 1000) { png_warning(png_ptr, "Ignoring incorrect cHRM value when sRGB is also present"); } #endif /* PNG_FIXED_POINT_SUPPORTED */ #endif /* PNG_READ_cHRM_SUPPORTED */ png_set_sRGB_gAMA_and_cHRM(png_ptr, info_ptr, intent); } #endif /* PNG_READ_sRGB_SUPPORTED */ #if defined(PNG_READ_iCCP_SUPPORTED) void /* PRIVATE */ png_handle_iCCP(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) /* Note: this does not properly handle chunks that are > 64K under DOS */ { png_charp chunkdata; png_byte compression_type; png_charp profile; png_uint_32 skip = 0; png_size_t slength, prefix_length, data_length; png_debug(1, "in png_handle_iCCP\n"); if (!(png_ptr->mode & PNG_HAVE_IHDR)) png_error(png_ptr, "Missing IHDR before iCCP"); else if (png_ptr->mode & PNG_HAVE_IDAT) { png_warning(png_ptr, "Invalid iCCP after IDAT"); png_crc_finish(png_ptr, length); return; } else if (png_ptr->mode & PNG_HAVE_PLTE) /* Should be an error, but we can cope with it */ png_warning(png_ptr, "Out of place iCCP chunk"); else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_iCCP)) { png_warning(png_ptr, "Duplicate iCCP chunk"); png_crc_finish(png_ptr, length); return; } #ifdef PNG_MAX_MALLOC_64K if (length > (png_uint_32)65535L) { png_warning(png_ptr, "iCCP chunk too large to fit in memory"); skip = length - (png_uint_32)65535L; length = (png_uint_32)65535L; } #endif chunkdata = (png_charp)png_malloc(png_ptr, length + 1); slength = (png_size_t)length; png_crc_read(png_ptr, (png_bytep)chunkdata, slength); if (png_crc_finish(png_ptr, skip)) { png_free(png_ptr, chunkdata); return; } chunkdata[slength] = 0x00; for (profile = chunkdata; *profile; profile++) /* empty loop to find end of name */ ; ++profile; /* there should be at least one zero (the compression type byte) following the separator, and we should be on it */ if (*profile || profile >= chunkdata + slength) { png_free(png_ptr, chunkdata); png_warning(png_ptr, "malformed iCCP chunk"); return; } /* compression_type should always be zero */ compression_type = *profile++; prefix_length = profile - chunkdata; chunkdata = png_decompress_chunk(png_ptr, compression_type, chunkdata, slength, prefix_length, &data_length); png_set_iCCP(png_ptr, info_ptr, chunkdata, compression_type, chunkdata + prefix_length, data_length); png_free(png_ptr, chunkdata); } #endif /* PNG_READ_iCCP_SUPPORTED */ #if defined(PNG_READ_sPLT_SUPPORTED) void /* PRIVATE */ png_handle_sPLT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) /* Note: this does not properly handle chunks that are > 64K under DOS */ { png_bytep chunkdata; png_bytep entry_start; png_sPLT_t new_palette; #ifdef PNG_NO_POINTER_INDEXING png_sPLT_entryp pp; #endif int data_length, entry_size, i; png_uint_32 skip = 0; png_size_t slength; png_debug(1, "in png_handle_sPLT\n"); if (!(png_ptr->mode & PNG_HAVE_IHDR)) png_error(png_ptr, "Missing IHDR before sPLT"); else if (png_ptr->mode & PNG_HAVE_IDAT) { png_warning(png_ptr, "Invalid sPLT after IDAT"); png_crc_finish(png_ptr, length); return; } #ifdef PNG_MAX_MALLOC_64K if (length > (png_uint_32)65535L) { png_warning(png_ptr, "sPLT chunk too large to fit in memory"); skip = length - (png_uint_32)65535L; length = (png_uint_32)65535L; } #endif chunkdata = (png_bytep)png_malloc(png_ptr, length + 1); slength = (png_size_t)length; png_crc_read(png_ptr, chunkdata, slength); if (png_crc_finish(png_ptr, skip)) { png_free(png_ptr, chunkdata); return; } chunkdata[slength] = 0x00; for (entry_start = chunkdata; *entry_start; entry_start++) /* empty loop to find end of name */ ; ++entry_start; /* a sample depth should follow the separator, and we should be on it */ if (entry_start > chunkdata + slength) { png_free(png_ptr, chunkdata); png_warning(png_ptr, "malformed sPLT chunk"); return; } new_palette.depth = *entry_start++; entry_size = (new_palette.depth == 8 ? 6 : 10); data_length = (slength - (entry_start - chunkdata)); /* integrity-check the data length */ if (data_length % entry_size) { png_free(png_ptr, chunkdata); png_error(png_ptr, "sPLT chunk has bad length"); } new_palette.nentries = data_length / entry_size; new_palette.entries = (png_sPLT_entryp)png_malloc( png_ptr, new_palette.nentries * sizeof(png_sPLT_entry)); #ifndef PNG_NO_POINTER_INDEXING for (i = 0; i < new_palette.nentries; i++) { png_sPLT_entryp pp = new_palette.entries + i; if (new_palette.depth == 8) { pp->red = *entry_start++; pp->green = *entry_start++; pp->blue = *entry_start++; pp->alpha = *entry_start++; } else { pp->red = png_get_uint_16(entry_start); entry_start += 2; pp->green = png_get_uint_16(entry_start); entry_start += 2; pp->blue = png_get_uint_16(entry_start); entry_start += 2; pp->alpha = png_get_uint_16(entry_start); entry_start += 2; } pp->frequency = png_get_uint_16(entry_start); entry_start += 2; } #else pp = new_palette.entries; for (i = 0; i < new_palette.nentries; i++) { if (new_palette.depth == 8) { pp[i].red = *entry_start++; pp[i].green = *entry_start++; pp[i].blue = *entry_start++; pp[i].alpha = *entry_start++; } else { pp[i].red = png_get_uint_16(entry_start); entry_start += 2; pp[i].green = png_get_uint_16(entry_start); entry_start += 2; pp[i].blue = png_get_uint_16(entry_start); entry_start += 2; pp[i].alpha = png_get_uint_16(entry_start); entry_start += 2; } pp->frequency = png_get_uint_16(entry_start); entry_start += 2; } #endif /* discard all chunk data except the name and stash that */ new_palette.name = (png_charp)chunkdata; png_set_sPLT(png_ptr, info_ptr, &new_palette, 1); png_free(png_ptr, chunkdata); png_free(png_ptr, new_palette.entries); } #endif /* PNG_READ_sPLT_SUPPORTED */ #if defined(PNG_READ_tRNS_SUPPORTED) void /* PRIVATE */ png_handle_tRNS(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) { png_debug(1, "in png_handle_tRNS\n"); if (!(png_ptr->mode & PNG_HAVE_IHDR)) png_error(png_ptr, "Missing IHDR before tRNS"); else if (png_ptr->mode & PNG_HAVE_IDAT) { png_warning(png_ptr, "Invalid tRNS after IDAT"); png_crc_finish(png_ptr, length); return; } else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS)) { png_warning(png_ptr, "Duplicate tRNS chunk"); png_crc_finish(png_ptr, length); return; } if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) { if (!(png_ptr->mode & PNG_HAVE_PLTE)) { /* Should be an error, but we can cope with it */ png_warning(png_ptr, "Missing PLTE before tRNS"); } else if (length > (png_uint_32)png_ptr->num_palette) { png_warning(png_ptr, "Incorrect tRNS chunk length"); png_crc_finish(png_ptr, length); return; } if (length == 0) { png_warning(png_ptr, "Zero length tRNS chunk"); png_crc_finish(png_ptr, length); return; } png_ptr->trans = (png_bytep)png_malloc(png_ptr, length); png_crc_read(png_ptr, png_ptr->trans, (png_size_t)length); png_ptr->num_trans = (png_uint_16)length; } else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB) { png_byte buf[6]; if (length != 6) { png_warning(png_ptr, "Incorrect tRNS chunk length"); png_crc_finish(png_ptr, length); return; } png_crc_read(png_ptr, buf, (png_size_t)length); png_ptr->num_trans = 1; png_ptr->trans_values.red = png_get_uint_16(buf); png_ptr->trans_values.green = png_get_uint_16(buf + 2); png_ptr->trans_values.blue = png_get_uint_16(buf + 4); } else if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY) { png_byte buf[6]; if (length != 2) { png_warning(png_ptr, "Incorrect tRNS chunk length"); png_crc_finish(png_ptr, length); return; } png_crc_read(png_ptr, buf, 2); png_ptr->num_trans = 1; png_ptr->trans_values.gray = png_get_uint_16(buf); } else { png_warning(png_ptr, "tRNS chunk not allowed with alpha channel"); png_crc_finish(png_ptr, length); return; } if (png_crc_finish(png_ptr, 0)) return; #ifdef PNG_FREE_ME_SUPPORTED png_free_data(png_ptr, info_ptr, PNG_FREE_TRNS, 0); png_ptr->free_me |= PNG_FREE_TRNS; #else png_ptr->flags |= PNG_FLAG_FREE_TRNS; #endif png_set_tRNS(png_ptr, info_ptr, png_ptr->trans, png_ptr->num_trans, &(png_ptr->trans_values)); } #endif #if defined(PNG_READ_bKGD_SUPPORTED) void /* PRIVATE */ png_handle_bKGD(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) { png_size_t truelen; png_byte buf[6]; png_debug(1, "in png_handle_bKGD\n"); if (!(png_ptr->mode & PNG_HAVE_IHDR)) png_error(png_ptr, "Missing IHDR before bKGD"); else if (png_ptr->mode & PNG_HAVE_IDAT) { png_warning(png_ptr, "Invalid bKGD after IDAT"); png_crc_finish(png_ptr, length); return; } else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE && !(png_ptr->mode & PNG_HAVE_PLTE)) { png_warning(png_ptr, "Missing PLTE before bKGD"); png_crc_finish(png_ptr, length); return; } else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_bKGD)) { png_warning(png_ptr, "Duplicate bKGD chunk"); png_crc_finish(png_ptr, length); return; } if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) truelen = 1; else if (png_ptr->color_type & PNG_COLOR_MASK_COLOR) truelen = 6; else truelen = 2; if (length != truelen) { png_warning(png_ptr, "Incorrect bKGD chunk length"); png_crc_finish(png_ptr, length); return; } png_crc_read(png_ptr, buf, truelen); if (png_crc_finish(png_ptr, 0)) return; /* We convert the index value into RGB components so that we can allow * arbitrary RGB values for background when we have transparency, and * so it is easy to determine the RGB values of the background color * from the info_ptr struct. */ if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) { png_ptr->background.index = buf[0]; if(info_ptr->num_palette) { if(buf[0] > info_ptr->num_palette) { png_warning(png_ptr, "Incorrect bKGD chunk index value"); png_crc_finish(png_ptr, length); return; } png_ptr->background.red = (png_uint_16)png_ptr->palette[buf[0]].red; png_ptr->background.green = (png_uint_16)png_ptr->palette[buf[0]].green; png_ptr->background.blue = (png_uint_16)png_ptr->palette[buf[0]].blue; } } 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); } 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); } png_set_bKGD(png_ptr, info_ptr, &(png_ptr->background)); } #endif #if defined(PNG_READ_hIST_SUPPORTED) void /* PRIVATE */ png_handle_hIST(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) { int num, i; png_debug(1, "in png_handle_hIST\n"); if (!(png_ptr->mode & PNG_HAVE_IHDR)) png_error(png_ptr, "Missing IHDR before hIST"); else if (png_ptr->mode & PNG_HAVE_IDAT) { png_warning(png_ptr, "Invalid hIST after IDAT"); png_crc_finish(png_ptr, length); return; } else if (!(png_ptr->mode & PNG_HAVE_PLTE)) { png_warning(png_ptr, "Missing PLTE before hIST"); png_crc_finish(png_ptr, length); return; } else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_hIST)) { png_warning(png_ptr, "Duplicate hIST chunk"); png_crc_finish(png_ptr, length); return; } if (length != (png_uint_32)(2 * png_ptr->num_palette)) { png_warning(png_ptr, "Incorrect hIST chunk length"); png_crc_finish(png_ptr, length); return; } num = (int)length / 2 ; png_ptr->hist = (png_uint_16p)png_malloc(png_ptr, (png_uint_32)(num * sizeof (png_uint_16))); for (i = 0; i < num; i++) { png_byte buf[2]; png_crc_read(png_ptr, buf, 2); png_ptr->hist[i] = png_get_uint_16(buf); } if (png_crc_finish(png_ptr, 0)) return; #ifdef PNG_FREE_ME_SUPPORTED png_free_data(png_ptr, info_ptr, PNG_FREE_HIST, 0); png_ptr->free_me |= PNG_FREE_HIST; #else png_ptr->flags |= PNG_FLAG_FREE_HIST; #endif png_set_hIST(png_ptr, info_ptr, png_ptr->hist); } #endif #if defined(PNG_READ_pHYs_SUPPORTED) void /* PRIVATE */ png_handle_pHYs(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) { png_byte buf[9]; png_uint_32 res_x, res_y; int unit_type; png_debug(1, "in png_handle_pHYs\n"); if (!(png_ptr->mode & PNG_HAVE_IHDR)) png_error(png_ptr, "Missing IHDR before pHYs"); else if (png_ptr->mode & PNG_HAVE_IDAT) { png_warning(png_ptr, "Invalid pHYs after IDAT"); png_crc_finish(png_ptr, length); return; } else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs)) { png_warning(png_ptr, "Duplicate pHYs chunk"); png_crc_finish(png_ptr, length); return; } if (length != 9) { png_warning(png_ptr, "Incorrect pHYs chunk length"); png_crc_finish(png_ptr, length); return; } png_crc_read(png_ptr, buf, 9); if (png_crc_finish(png_ptr, 0)) return; res_x = png_get_uint_32(buf); res_y = png_get_uint_32(buf + 4); unit_type = buf[8]; png_set_pHYs(png_ptr, info_ptr, res_x, res_y, unit_type); } #endif #if defined(PNG_READ_oFFs_SUPPORTED) void /* PRIVATE */ png_handle_oFFs(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) { png_byte buf[9]; png_int_32 offset_x, offset_y; int unit_type; png_debug(1, "in png_handle_oFFs\n"); if (!(png_ptr->mode & PNG_HAVE_IHDR)) png_error(png_ptr, "Missing IHDR before oFFs"); else if (png_ptr->mode & PNG_HAVE_IDAT) { png_warning(png_ptr, "Invalid oFFs after IDAT"); png_crc_finish(png_ptr, length); return; } else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs)) { png_warning(png_ptr, "Duplicate oFFs chunk"); png_crc_finish(png_ptr, length); return; } if (length != 9) { png_warning(png_ptr, "Incorrect oFFs chunk length"); png_crc_finish(png_ptr, length); return; } png_crc_read(png_ptr, buf, 9); if (png_crc_finish(png_ptr, 0)) return; offset_x = png_get_int_32(buf); offset_y = png_get_int_32(buf + 4); unit_type = buf[8]; png_set_oFFs(png_ptr, info_ptr, offset_x, offset_y, unit_type); } #endif #if defined(PNG_READ_pCAL_SUPPORTED) /* read the pCAL chunk (png-scivis-19970203) */ void /* PRIVATE */ png_handle_pCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) { png_charp purpose; png_int_32 X0, X1; png_byte type, nparams; png_charp buf, units, endptr; png_charpp params; png_size_t slength; int i; png_debug(1, "in png_handle_pCAL\n"); if (!(png_ptr->mode & PNG_HAVE_IHDR)) png_error(png_ptr, "Missing IHDR before pCAL"); else if (png_ptr->mode & PNG_HAVE_IDAT) { png_warning(png_ptr, "Invalid pCAL after IDAT"); png_crc_finish(png_ptr, length); return; } else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_pCAL)) { png_warning(png_ptr, "Duplicate pCAL chunk"); png_crc_finish(png_ptr, length); return; } png_debug1(2, "Allocating and reading pCAL chunk data (%d bytes)\n", length + 1); purpose = (png_charp)png_malloc(png_ptr, length + 1); slength = (png_size_t)length; png_crc_read(png_ptr, (png_bytep)purpose, slength); if (png_crc_finish(png_ptr, 0)) { png_free(png_ptr, purpose); return; } purpose[slength] = 0x00; /* null terminate the last string */ png_debug(3, "Finding end of pCAL purpose string\n"); for (buf = purpose; *buf; buf++) /* empty loop */ ; endptr = purpose + slength; /* We need to have at least 12 bytes after the purpose string in order to get the parameter information. */ if (endptr <= buf + 12) { png_warning(png_ptr, "Invalid pCAL data"); png_free(png_ptr, purpose); return; } png_debug(3, "Reading pCAL X0, X1, type, nparams, and units\n"); X0 = png_get_int_32((png_bytep)buf+1); X1 = png_get_int_32((png_bytep)buf+5); type = buf[9]; nparams = buf[10]; units = buf + 11; png_debug(3, "Checking pCAL equation type and number of parameters\n"); /* Check that we have the right number of parameters for known equation types. */ if ((type == PNG_EQUATION_LINEAR && nparams != 2) || (type == PNG_EQUATION_BASE_E && nparams != 3) || (type == PNG_EQUATION_ARBITRARY && nparams != 3) || (type == PNG_EQUATION_HYPERBOLIC && nparams != 4)) { png_warning(png_ptr, "Invalid pCAL parameters for equation type"); png_free(png_ptr, purpose); return; } else if (type >= PNG_EQUATION_LAST) { png_warning(png_ptr, "Unrecognized equation type for pCAL chunk"); } for (buf = units; *buf; buf++) /* Empty loop to move past the units string. */ ; png_debug(3, "Allocating pCAL parameters array\n"); params = (png_charpp)png_malloc(png_ptr, (png_uint_32)(nparams *sizeof(png_charp))) ; /* Get pointers to the start of each parameter string. */ for (i = 0; i < (int)nparams; i++) { buf++; /* Skip the null string terminator from previous parameter. */ png_debug1(3, "Reading pCAL parameter %d\n", i); for (params[i] = buf; *buf != 0x00 && buf <= endptr; buf++) /* Empty loop to move past each parameter string */ ; /* Make sure we haven't run out of data yet */ if (buf > endptr) { png_warning(png_ptr, "Invalid pCAL data"); png_free(png_ptr, purpose); png_free(png_ptr, params); return; } } png_set_pCAL(png_ptr, info_ptr, purpose, X0, X1, type, nparams, units, params); png_free(png_ptr, purpose); png_free(png_ptr, params); } #endif #if defined(PNG_READ_sCAL_SUPPORTED) /* read the sCAL chunk */ void /* PRIVATE */ png_handle_sCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) { png_charp buffer, ep; #ifdef PNG_FLOATING_POINT_SUPPORTED double width, height; png_charp vp; #else #ifdef PNG_FIXED_POINT_SUPPORTED png_charp swidth, sheight; #endif #endif png_size_t slength; png_debug(1, "in png_handle_sCAL\n"); if (!(png_ptr->mode & PNG_HAVE_IHDR)) png_error(png_ptr, "Missing IHDR before sCAL"); else if (png_ptr->mode & PNG_HAVE_IDAT) { png_warning(png_ptr, "Invalid sCAL after IDAT"); png_crc_finish(png_ptr, length); return; } else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sCAL)) { png_warning(png_ptr, "Duplicate sCAL chunk"); png_crc_finish(png_ptr, length); return; } png_debug1(2, "Allocating and reading sCAL chunk data (%d bytes)\n", length + 1); buffer = (png_charp)png_malloc(png_ptr, length + 1); slength = (png_size_t)length; png_crc_read(png_ptr, (png_bytep)buffer, slength); if (png_crc_finish(png_ptr, 0)) { png_free(png_ptr, buffer); return; } buffer[slength] = 0x00; /* null terminate the last string */ ep = buffer + 1; /* skip unit byte */ #ifdef PNG_FLOATING_POINT_SUPPORTED width = strtod(ep, &vp); if (*vp) { png_warning(png_ptr, "malformed width string in sCAL chunk"); return; } #else #ifdef PNG_FIXED_POINT_SUPPORTED swidth = (png_charp)png_malloc(png_ptr, strlen(ep) + 1); png_memcpy(swidth, ep, (png_size_t)strlen(ep)); #endif #endif for (ep = buffer; *ep; ep++) /* empty loop */ ; ep++; #ifdef PNG_FLOATING_POINT_SUPPORTED height = strtod(ep, &vp); if (*vp) { png_warning(png_ptr, "malformed height string in sCAL chunk"); return; } #else #ifdef PNG_FIXED_POINT_SUPPORTED sheight = (png_charp)png_malloc(png_ptr, strlen(ep) + 1); png_memcpy(sheight, ep, (png_size_t)strlen(ep)); #endif #endif if (buffer + slength < ep #ifdef PNG_FLOATING_POINT_SUPPORTED || width <= 0. || height <= 0. #endif ) { png_warning(png_ptr, "Invalid sCAL data"); png_free(png_ptr, buffer); #if defined(PNG_FIXED_POINT_SUPPORTED) && !defined(PNG_FLOATING_POINT_SUPPORTED) png_free(png_ptr, swidth); png_free(png_ptr, sheight); #endif return; } #ifdef PNG_FLOATING_POINT_SUPPORTED png_set_sCAL(png_ptr, info_ptr, buffer[0], width, height); #else #ifdef PNG_FIXED_POINT_SUPPORTED png_set_sCAL_s(png_ptr, info_ptr, buffer[0], swidth, sheight); #endif #endif png_free(png_ptr, buffer); #if defined(PNG_FIXED_POINT_SUPPORTED) && !defined(PNG_FLOATING_POINT_SUPPORTED) png_free(png_ptr, swidth); png_free(png_ptr, sheight); #endif } #endif #if defined(PNG_READ_tIME_SUPPORTED) void /* PRIVATE */ png_handle_tIME(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) { png_byte buf[7]; png_time mod_time; png_debug(1, "in png_handle_tIME\n"); if (!(png_ptr->mode & PNG_HAVE_IHDR)) png_error(png_ptr, "Out of place tIME chunk"); else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tIME)) { png_warning(png_ptr, "Duplicate tIME chunk"); png_crc_finish(png_ptr, length); return; } if (png_ptr->mode & PNG_HAVE_IDAT) png_ptr->mode |= PNG_AFTER_IDAT; if (length != 7) { png_warning(png_ptr, "Incorrect tIME chunk length"); png_crc_finish(png_ptr, length); return; } png_crc_read(png_ptr, buf, 7); if (png_crc_finish(png_ptr, 0)) return; mod_time.second = buf[6]; mod_time.minute = buf[5]; mod_time.hour = buf[4]; mod_time.day = buf[3]; mod_time.month = buf[2]; mod_time.year = png_get_uint_16(buf); png_set_tIME(png_ptr, info_ptr, &mod_time); } #endif #if defined(PNG_READ_tEXt_SUPPORTED) /* Note: this does not properly handle chunks that are > 64K under DOS */ void /* PRIVATE */ png_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) { png_textp text_ptr; png_charp key; png_charp text; png_uint_32 skip = 0; png_size_t slength; png_debug(1, "in png_handle_tEXt\n"); if (!(png_ptr->mode & PNG_HAVE_IHDR)) png_error(png_ptr, "Missing IHDR before tEXt"); if (png_ptr->mode & PNG_HAVE_IDAT) png_ptr->mode |= PNG_AFTER_IDAT; #ifdef PNG_MAX_MALLOC_64K if (length > (png_uint_32)65535L) { png_warning(png_ptr, "tEXt chunk too large to fit in memory"); skip = length - (png_uint_32)65535L; length = (png_uint_32)65535L; } #endif key = (png_charp)png_malloc(png_ptr, length + 1); slength = (png_size_t)length; png_crc_read(png_ptr, (png_bytep)key, slength); if (png_crc_finish(png_ptr, skip)) { png_free(png_ptr, key); return; } key[slength] = 0x00; for (text = key; *text; text++) /* empty loop to find end of key */ ; if (text != key + slength) text++; text_ptr = (png_textp)png_malloc(png_ptr, (png_uint_32)sizeof(png_text)); text_ptr->compression = PNG_TEXT_COMPRESSION_NONE; text_ptr->key = key; #ifdef PNG_iTXt_SUPPORTED text_ptr->lang = NULL; text_ptr->lang_key = NULL; text_ptr->itxt_length = 0; #endif text_ptr->text = text; text_ptr->text_length = png_strlen(text); png_set_text(png_ptr, info_ptr, text_ptr, 1); png_free(png_ptr, key); png_free(png_ptr, text_ptr); } #endif #if defined(PNG_READ_zTXt_SUPPORTED) /* note: this does not correctly handle chunks that are > 64K under DOS */ void /* PRIVATE */ png_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) { png_textp text_ptr; png_charp chunkdata; png_charp text; int comp_type; png_size_t slength, prefix_len, data_len; png_debug(1, "in png_handle_zTXt\n"); if (!(png_ptr->mode & PNG_HAVE_IHDR)) png_error(png_ptr, "Missing IHDR before zTXt"); if (png_ptr->mode & PNG_HAVE_IDAT) png_ptr->mode |= PNG_AFTER_IDAT; #ifdef PNG_MAX_MALLOC_64K /* We will no doubt have problems with chunks even half this size, but there is no hard and fast rule to tell us where to stop. */ if (length > (png_uint_32)65535L) { png_warning(png_ptr,"zTXt chunk too large to fit in memory"); png_crc_finish(png_ptr, length); return; } #endif chunkdata = (png_charp)png_malloc(png_ptr, length + 1); slength = (png_size_t)length; png_crc_read(png_ptr, (png_bytep)chunkdata, slength); if (png_crc_finish(png_ptr, 0)) { png_free(png_ptr, chunkdata); return; } chunkdata[slength] = 0x00; for (text = chunkdata; *text; text++) /* empty loop */ ; /* zTXt must have some text after the chunkdataword */ if (text == chunkdata + slength) { comp_type = PNG_TEXT_COMPRESSION_NONE; png_warning(png_ptr, "Zero length zTXt chunk"); } else { comp_type = *(++text); text++; /* skip the compression_method byte */ } prefix_len = text - chunkdata; chunkdata = (png_charp)png_decompress_chunk(png_ptr, comp_type, chunkdata, (png_size_t)length, prefix_len, &data_len); text_ptr = (png_textp)png_malloc(png_ptr, (png_uint_32)sizeof(png_text)); text_ptr->compression = comp_type; text_ptr->key = chunkdata; #ifdef PNG_iTXt_SUPPORTED text_ptr->lang = NULL; text_ptr->lang_key = NULL; text_ptr->itxt_length = 0; #endif text_ptr->text = chunkdata + prefix_len; text_ptr->text_length = data_len; png_set_text(png_ptr, info_ptr, text_ptr, 1); png_free(png_ptr, text_ptr); png_free(png_ptr, chunkdata); } #endif #if defined(PNG_READ_iTXt_SUPPORTED) /* note: this does not correctly handle chunks that are > 64K under DOS */ void /* PRIVATE */ png_handle_iTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) { png_textp text_ptr; png_charp chunkdata; png_charp key, lang, text, lang_key; int comp_flag; int comp_type = 0; png_size_t slength, prefix_len, data_len; png_debug(1, "in png_handle_iTXt\n"); if (!(png_ptr->mode & PNG_HAVE_IHDR)) png_error(png_ptr, "Missing IHDR before iTXt"); if (png_ptr->mode & PNG_HAVE_IDAT) png_ptr->mode |= PNG_AFTER_IDAT; #ifdef PNG_MAX_MALLOC_64K /* We will no doubt have problems with chunks even half this size, but there is no hard and fast rule to tell us where to stop. */ if (length > (png_uint_32)65535L) { png_warning(png_ptr,"iTXt chunk too large to fit in memory"); png_crc_finish(png_ptr, length); return; } #endif chunkdata = (png_charp)png_malloc(png_ptr, length + 1); slength = (png_size_t)length; png_crc_read(png_ptr, (png_bytep)chunkdata, slength); if (png_crc_finish(png_ptr, 0)) { png_free(png_ptr, chunkdata); return; } chunkdata[slength] = 0x00; for (lang = chunkdata; *lang; lang++) /* empty loop */ ; lang++; /* skip NUL separator */ /* iTXt must have a language tag (possibly empty), two compression bytes, translated keyword (possibly empty), and possibly some text after the keyword */ if (lang >= chunkdata + slength) { comp_flag = PNG_TEXT_COMPRESSION_NONE; png_warning(png_ptr, "Zero length iTXt chunk"); } else { comp_flag = *lang++; comp_type = *lang++; } for (lang_key = lang; *lang_key; lang_key++) /* empty loop */ ; lang_key++; /* skip NUL separator */ for (text = lang_key; *text; text++) /* empty loop */ ; text++; /* skip NUL separator */ prefix_len = text - chunkdata; key=chunkdata; if (comp_flag) chunkdata = png_decompress_chunk(png_ptr, comp_type, chunkdata, (size_t)length, prefix_len, &data_len); else data_len=png_strlen(chunkdata + prefix_len); text_ptr = (png_textp)png_malloc(png_ptr, (png_uint_32)sizeof(png_text)); text_ptr->compression = (int)comp_flag + 1; text_ptr->lang_key = chunkdata+(lang_key-key); text_ptr->lang = chunkdata+(lang-key); text_ptr->itxt_length = data_len; text_ptr->text_length = 0; text_ptr->key = chunkdata; text_ptr->text = chunkdata + prefix_len; png_set_text(png_ptr, info_ptr, text_ptr, 1); png_free(png_ptr, text_ptr); png_free(png_ptr, chunkdata); } #endif /* This function is called when we haven't found a handler for a chunk. If there isn't a problem with the chunk itself (ie bad chunk name, CRC, or a critical chunk), the chunk is silently ignored -- unless the PNG_FLAG_UNKNOWN_CHUNKS_SUPPORTED flag is on in which case it will be saved away to be written out later. */ void /* PRIVATE */ png_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) { png_uint_32 skip = 0; png_debug(1, "in png_handle_unknown\n"); if (png_ptr->mode & PNG_HAVE_IDAT) { #ifdef PNG_USE_LOCAL_ARRAYS PNG_IDAT; #endif if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) /* not an IDAT */ png_ptr->mode |= PNG_AFTER_IDAT; } png_check_chunk_name(png_ptr, png_ptr->chunk_name); if (!(png_ptr->chunk_name[0] & 0x20)) { #if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED) if(png_handle_as_unknown(png_ptr, png_ptr->chunk_name) != HANDLE_CHUNK_ALWAYS #if defined(PNG_READ_USER_CHUNKS_SUPPORTED) && png_ptr->read_user_chunk_fn == (png_user_chunk_ptr)NULL #endif ) #endif png_chunk_error(png_ptr, "unknown critical chunk"); } #if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED) if (png_ptr->flags & PNG_FLAG_KEEP_UNKNOWN_CHUNKS) { png_unknown_chunk chunk; #ifdef PNG_MAX_MALLOC_64K if (length > (png_uint_32)65535L) { png_warning(png_ptr, "unknown chunk too large to fit in memory"); skip = length - (png_uint_32)65535L; length = (png_uint_32)65535L; } #endif strcpy((png_charp)chunk.name, (png_charp)png_ptr->chunk_name); chunk.data = (png_bytep)png_malloc(png_ptr, length); png_crc_read(png_ptr, chunk.data, length); chunk.size = length; #if defined(PNG_READ_USER_CHUNKS_SUPPORTED) if(png_ptr->read_user_chunk_fn != (png_user_chunk_ptr)NULL) { /* callback to user unknown chunk handler */ if ((*(png_ptr->read_user_chunk_fn)) (png_ptr, &chunk) <= 0) { if (!(png_ptr->chunk_name[0] & 0x20)) if(png_handle_as_unknown(png_ptr, png_ptr->chunk_name) != HANDLE_CHUNK_ALWAYS) png_chunk_error(png_ptr, "unknown critical chunk"); png_set_unknown_chunks(png_ptr, info_ptr, &chunk, 1); } } else #endif png_set_unknown_chunks(png_ptr, info_ptr, &chunk, 1); png_free(png_ptr, chunk.data); } else #endif skip = length; png_crc_finish(png_ptr, skip); #if !defined(PNG_READ_USER_CHUNKS_SUPPORTED) if (info_ptr == NULL) /* quiet compiler warnings about unused info_ptr */ ; #endif } /* This function is called to verify that a chunk name is valid. This function can't have the "critical chunk check" incorporated into it, since in the future we will need to be able to call user functions to handle unknown critical chunks after we check that the chunk name itself is valid. */ #define isnonalpha(c) ((c) < 41 || (c) > 122 || ((c) > 90 && (c) < 97)) void /* PRIVATE */ png_check_chunk_name(png_structp png_ptr, png_bytep chunk_name) { png_debug(1, "in png_check_chunk_name\n"); if (isnonalpha(chunk_name[0]) || isnonalpha(chunk_name[1]) || isnonalpha(chunk_name[2]) || isnonalpha(chunk_name[3])) { png_chunk_error(png_ptr, "invalid chunk type"); } } /* 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. */ void /* PRIVATE */ #ifdef PNG_HAVE_ASSEMBLER_COMBINE_ROW png_combine_row_c #else png_combine_row #endif /* PNG_HAVE_ASSEMBLER_COMBINE_ROW */ (png_structp png_ptr, png_bytep row, int mask) { png_debug(1,"in png_combine_row\n"); if (mask == 0xff) { png_memcpy(row, png_ptr->row_buf + 1, (png_size_t)((png_ptr->width * png_ptr->row_info.pixel_depth + 7) >> 3)); } else { switch (png_ptr->row_info.pixel_depth) { case 1: { 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; #if defined(PNG_READ_PACKSWAP_SUPPORTED) if (png_ptr->transformations & PNG_PACKSWAP) { s_start = 0; s_end = 7; s_inc = 1; } else #endif { s_start = 7; s_end = 0; s_inc = -1; } shift = s_start; for (i = 0; i < row_width; i++) { if (m & mask) { int value; value = (*sp >> shift) & 0x01; *dp &= (png_byte)((0x7f7f >> (7 - shift)) & 0xff); *dp |= (png_byte)(value << shift); } if (shift == s_end) { shift = s_start; sp++; dp++; } else shift += s_inc; if (m == 1) m = 0x80; else m >>= 1; } break; } case 2: { 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; #if defined(PNG_READ_PACKSWAP_SUPPORTED) if (png_ptr->transformations & PNG_PACKSWAP) { s_start = 0; s_end = 6; s_inc = 2; } else #endif { s_start = 6; s_end = 0; s_inc = -2; } shift = s_start; 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); } if (shift == s_end) { shift = s_start; sp++; dp++; } else shift += s_inc; if (m == 1) m = 0x80; else m >>= 1; } break; } 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; #if defined(PNG_READ_PACKSWAP_SUPPORTED) if (png_ptr->transformations & PNG_PACKSWAP) { s_start = 0; s_end = 4; s_inc = 4; } else #endif { s_start = 4; s_end = 0; s_inc = -4; } shift = s_start; 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); } if (shift == s_end) { shift = s_start; sp++; dp++; } else shift += s_inc; if (m == 1) m = 0x80; else m >>= 1; } break; } 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); } sp += pixel_bytes; dp += pixel_bytes; if (m == 1) m = 0x80; else m >>= 1; } break; } } } } #if defined(PNG_READ_INTERLACING_SUPPORTED) void /* PRIVATE */ #ifdef PNG_HAVE_ASSEMBLER_READ_INTERLACE png_do_read_interlace_c #else png_do_read_interlace #endif /* PNG_HAVE_ASSEMBLER_READ_INTERLACE */ (png_row_infop row_info, png_bytep row, int pass, png_uint_32 transformations) { #ifdef PNG_USE_LOCAL_ARRAYS /* arrays to facilitate easy interlacing - use pass (0 - 6) as index */ /* offset to next interlace block */ const int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; #endif png_debug(1,"in png_do_read_interlace\n"); if (row != NULL && row_info != NULL) { png_uint_32 final_width; final_width = row_info->width * png_pass_inc[pass]; switch (row_info->pixel_depth) { case 1: { png_bytep sp = row + (png_size_t)((row_info->width - 1) >> 3); png_bytep dp = row + (png_size_t)((final_width - 1) >> 3); int sshift, dshift; int s_start, s_end, s_inc; int jstop = png_pass_inc[pass]; png_byte v; png_uint_32 i; int j; #if defined(PNG_READ_PACKSWAP_SUPPORTED) if (transformations & PNG_PACKSWAP) { sshift = (int)((row_info->width + 7) & 0x07); dshift = (int)((final_width + 7) & 0x07); s_start = 7; s_end = 0; s_inc = -1; } else #endif { sshift = 7 - (int)((row_info->width + 7) & 0x07); dshift = 7 - (int)((final_width + 7) & 0x07); s_start = 0; s_end = 7; s_inc = 1; } for (i = 0; i < row_info->width; i++) { v = (png_byte)((*sp >> sshift) & 0x01); for (j = 0; j < jstop; j++) { *dp &= (png_byte)((0x7f7f >> (7 - dshift)) & 0xff); *dp |= (png_byte)(v << dshift); if (dshift == s_end) { dshift = s_start; dp--; } else dshift += s_inc; } if (sshift == s_end) { sshift = s_start; sp--; } else sshift += s_inc; } break; } case 2: { png_bytep sp = row + (png_uint_32)((row_info->width - 1) >> 2); png_bytep dp = row + (png_uint_32)((final_width - 1) >> 2); int sshift, dshift; int s_start, s_end, s_inc; int jstop = png_pass_inc[pass]; png_uint_32 i; #if defined(PNG_READ_PACKSWAP_SUPPORTED) if (transformations & PNG_PACKSWAP) { sshift = (int)(((row_info->width + 3) & 0x03) << 1); dshift = (int)(((final_width + 3) & 0x03) << 1); s_start = 6; s_end = 0; s_inc = -2; } else #endif { sshift = (int)((3 - ((row_info->width + 3) & 0x03)) << 1); dshift = (int)((3 - ((final_width + 3) & 0x03)) << 1); s_start = 0; s_end = 6; s_inc = 2; } for (i = 0; i < row_info->width; i++) { png_byte v; int j; v = (png_byte)((*sp >> sshift) & 0x03); for (j = 0; j < jstop; j++) { *dp &= (png_byte)((0x3f3f >> (6 - dshift)) & 0xff); *dp |= (png_byte)(v << dshift); if (dshift == s_end) { dshift = s_start; dp--; } else dshift += s_inc; } if (sshift == s_end) { sshift = s_start; sp--; } else sshift += s_inc; } break; } case 4: { png_bytep sp = row + (png_size_t)((row_info->width - 1) >> 1); png_bytep dp = row + (png_size_t)((final_width - 1) >> 1); int sshift, dshift; int s_start, s_end, s_inc; png_uint_32 i; int jstop = png_pass_inc[pass]; #if defined(PNG_READ_PACKSWAP_SUPPORTED) if (transformations & PNG_PACKSWAP) { sshift = (int)(((row_info->width + 1) & 0x01) << 2); dshift = (int)(((final_width + 1) & 0x01) << 2); s_start = 4; s_end = 0; s_inc = -4; } else #endif { sshift = (int)((1 - ((row_info->width + 1) & 0x01)) << 2); dshift = (int)((1 - ((final_width + 1) & 0x01)) << 2); s_start = 0; s_end = 4; s_inc = 4; } for (i = 0; i < row_info->width; i++) { png_byte v = (png_byte)((*sp >> sshift) & 0xf); int j; for (j = 0; j < jstop; j++) { *dp &= (png_byte)((0xf0f >> (4 - dshift)) & 0xff); *dp |= (png_byte)(v << dshift); if (dshift == s_end) { dshift = s_start; dp--; } else dshift += s_inc; } if (sshift == s_end) { sshift = s_start; sp--; } else sshift += s_inc; } break; } default: { png_size_t pixel_bytes = (row_info->pixel_depth >> 3); png_bytep sp = row + (png_size_t)(row_info->width - 1) * pixel_bytes; png_bytep dp = row + (png_size_t)(final_width - 1) * pixel_bytes; int jstop = png_pass_inc[pass]; png_uint_32 i; for (i = 0; i < row_info->width; i++) { png_byte v[8]; int j; png_memcpy(v, sp, pixel_bytes); for (j = 0; j < jstop; j++) { png_memcpy(dp, v, pixel_bytes); dp -= pixel_bytes; } sp -= pixel_bytes; } break; } } row_info->width = final_width; row_info->rowbytes = ((final_width * (png_uint_32)row_info->pixel_depth + 7) >> 3); } #if !defined(PNG_READ_PACKSWAP_SUPPORTED) /* silence compiler warning */ if (transformations) return; #endif } #endif void /* PRIVATE */ #ifdef PNG_HAVE_ASSEMBLER_READ_FILTER_ROW png_read_filter_row_c #else png_read_filter_row #endif /* PNG_HAVE_ASSEMBLER_READ_FILTER_ROW */ (png_structp png_ptr, png_row_infop row_info, png_bytep row, png_bytep prev_row, int filter) { png_debug(1, "in png_read_filter_row\n"); png_debug2(2,"row = %d, filter = %d\n", png_ptr->row_number, filter); switch (filter) { case PNG_FILTER_VALUE_NONE: break; case PNG_FILTER_VALUE_SUB: { png_uint_32 i; png_uint_32 istop = row_info->rowbytes; png_uint_32 bpp = (row_info->pixel_depth + 7) >> 3; png_bytep rp = row + bpp; png_bytep lp = row; for (i = bpp; i < istop; i++) { *rp = (png_byte)(((int)(*rp) + (int)(*lp++)) & 0xff); rp++; } break; } case PNG_FILTER_VALUE_UP: { png_uint_32 i; png_uint_32 istop = row_info->rowbytes; png_bytep rp = row; png_bytep pp = prev_row; for (i = 0; i < istop; i++) { *rp = (png_byte)(((int)(*rp) + (int)(*pp++)) & 0xff); rp++; } break; } case PNG_FILTER_VALUE_AVG: { png_uint_32 i; png_bytep rp = row; png_bytep pp = prev_row; png_bytep lp = row; png_uint_32 bpp = (row_info->pixel_depth + 7) >> 3; png_uint_32 istop = row_info->rowbytes - bpp; for (i = 0; i < bpp; i++) { *rp = (png_byte)(((int)(*rp) + ((int)(*pp++) / 2 )) & 0xff); rp++; } for (i = 0; i < istop; i++) { *rp = (png_byte)(((int)(*rp) + (int)(*pp++ + *lp++) / 2 ) & 0xff); rp++; } break; } case PNG_FILTER_VALUE_PAETH: { png_uint_32 i; png_bytep rp = row; png_bytep pp = prev_row; png_bytep lp = row; png_bytep cp = prev_row; png_uint_32 bpp = (row_info->pixel_depth + 7) >> 3; png_uint_32 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++) /* use leftover rp,pp */ { int a, b, c, pa, pb, pc, p; a = *lp++; b = *pp++; c = *cp++; 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 (pa <= pb && pa <= pc) p = a; else if (pb <= pc) p = b; else p = c; */ p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c; *rp = (png_byte)(((int)(*rp) + p) & 0xff); rp++; } break; } default: png_warning(png_ptr, "Ignoring bad adaptive filter type"); *row=0; break; } } void /* PRIVATE */ png_read_finish_row(png_structp png_ptr) { #ifdef PNG_USE_LOCAL_ARRAYS /* arrays to facilitate easy interlacing - use pass (0 - 6) as index */ /* start of interlace block */ const int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; /* offset to next interlace block */ const int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; /* start of interlace block in the y direction */ const int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1}; /* offset to next interlace block in the y direction */ const int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; #endif png_debug(1, "in png_read_finish_row\n"); png_ptr->row_number++; if (png_ptr->row_number < png_ptr->num_rows) return; if (png_ptr->interlaced) { png_ptr->row_number = 0; png_memset_check(png_ptr, png_ptr->prev_row, 0, png_ptr->rowbytes + 1); do { png_ptr->pass++; if (png_ptr->pass >= 7) break; png_ptr->iwidth = (png_ptr->width + png_pass_inc[png_ptr->pass] - 1 - png_pass_start[png_ptr->pass]) / png_pass_inc[png_ptr->pass]; png_ptr->irowbytes = ((png_ptr->iwidth * (png_uint_32)png_ptr->pixel_depth + 7) >> 3) +1; if (!(png_ptr->transformations & PNG_INTERLACE)) { png_ptr->num_rows = (png_ptr->height + png_pass_yinc[png_ptr->pass] - 1 - png_pass_ystart[png_ptr->pass]) / png_pass_yinc[png_ptr->pass]; if (!(png_ptr->num_rows)) continue; } else /* if (png_ptr->transformations & PNG_INTERLACE) */ break; } while (png_ptr->iwidth == 0); if (png_ptr->pass < 7) return; } if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED)) { #ifdef PNG_USE_LOCAL_ARRAYS PNG_IDAT; #endif char extra; int ret; png_ptr->zstream.next_out = (Byte *)&extra; png_ptr->zstream.avail_out = (uInt)1; for(;;) { if (!(png_ptr->zstream.avail_in)) { while (!png_ptr->idat_size) { png_byte chunk_length[4]; png_crc_finish(png_ptr, 0); png_read_data(png_ptr, chunk_length, 4); png_ptr->idat_size = png_get_uint_32(chunk_length); png_reset_crc(png_ptr); png_crc_read(png_ptr, png_ptr->chunk_name, 4); if (png_memcmp(png_ptr->chunk_name, (png_bytep)png_IDAT, 4)) png_error(png_ptr, "Not enough image data"); } png_ptr->zstream.avail_in = (uInt)png_ptr->zbuf_size; png_ptr->zstream.next_in = png_ptr->zbuf; if (png_ptr->zbuf_size > png_ptr->idat_size) png_ptr->zstream.avail_in = (uInt)png_ptr->idat_size; png_crc_read(png_ptr, png_ptr->zbuf, png_ptr->zstream.avail_in); png_ptr->idat_size -= png_ptr->zstream.avail_in; } ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH); if (ret == Z_STREAM_END) { if (!(png_ptr->zstream.avail_out) || png_ptr->zstream.avail_in || png_ptr->idat_size) png_error(png_ptr, "Extra compressed data"); png_ptr->mode |= PNG_AFTER_IDAT; png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED; break; } if (ret != Z_OK) png_error(png_ptr, png_ptr->zstream.msg ? png_ptr->zstream.msg : "Decompression Error"); if (!(png_ptr->zstream.avail_out)) png_error(png_ptr, "Extra compressed data"); } png_ptr->zstream.avail_out = 0; } if (png_ptr->idat_size || png_ptr->zstream.avail_in) png_error(png_ptr, "Extra compression data"); inflateReset(&png_ptr->zstream); png_ptr->mode |= PNG_AFTER_IDAT; } void /* PRIVATE */ png_read_start_row(png_structp png_ptr) { #ifdef PNG_USE_LOCAL_ARRAYS /* arrays to facilitate easy interlacing - use pass (0 - 6) as index */ /* start of interlace block */ const int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; /* offset to next interlace block */ const int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; /* start of interlace block in the y direction */ const int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1}; /* offset to next interlace block in the y direction */ const int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; #endif int max_pixel_depth; png_uint_32 row_bytes; png_debug(1, "in png_read_start_row\n"); png_ptr->zstream.avail_in = 0; png_init_read_transformations(png_ptr); if (png_ptr->interlaced) { if (!(png_ptr->transformations & PNG_INTERLACE)) png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 - png_pass_ystart[0]) / png_pass_yinc[0]; else png_ptr->num_rows = png_ptr->height; png_ptr->iwidth = (png_ptr->width + png_pass_inc[png_ptr->pass] - 1 - png_pass_start[png_ptr->pass]) / png_pass_inc[png_ptr->pass]; row_bytes = ((png_ptr->iwidth * (png_uint_32)png_ptr->pixel_depth + 7) >> 3) +1; png_ptr->irowbytes = (png_size_t)row_bytes; if((png_uint_32)png_ptr->irowbytes != row_bytes) png_error(png_ptr, "Rowbytes overflow in png_read_start_row"); } else { png_ptr->num_rows = png_ptr->height; png_ptr->iwidth = png_ptr->width; png_ptr->irowbytes = png_ptr->rowbytes + 1; } max_pixel_depth = png_ptr->pixel_depth; #if defined(PNG_READ_PACK_SUPPORTED) if ((png_ptr->transformations & PNG_PACK) && png_ptr->bit_depth < 8) max_pixel_depth = 8; #endif #if defined(PNG_READ_EXPAND_SUPPORTED) if (png_ptr->transformations & PNG_EXPAND) { if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) { if (png_ptr->num_trans) max_pixel_depth = 32; else max_pixel_depth = 24; } else if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY) { if (max_pixel_depth < 8) max_pixel_depth = 8; if (png_ptr->num_trans) max_pixel_depth *= 2; } else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB) { if (png_ptr->num_trans) { max_pixel_depth *= 4; max_pixel_depth /= 3; } } } #endif #if defined(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 (max_pixel_depth <= 8) max_pixel_depth = 16; else max_pixel_depth = 32; } else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB) { if (max_pixel_depth <= 32) max_pixel_depth = 32; else max_pixel_depth = 64; } } #endif #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED) if (png_ptr->transformations & PNG_GRAY_TO_RGB) { if ( #if defined(PNG_READ_EXPAND_SUPPORTED) (png_ptr->num_trans && (png_ptr->transformations & PNG_EXPAND)) || #endif #if defined(PNG_READ_FILLER_SUPPORTED) (png_ptr->transformations & (PNG_FILLER)) || #endif png_ptr->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) { if (max_pixel_depth <= 16) max_pixel_depth = 32; else max_pixel_depth = 64; } else { if (max_pixel_depth <= 8) { if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA) max_pixel_depth = 32; else max_pixel_depth = 24; } else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA) max_pixel_depth = 64; else max_pixel_depth = 48; } } #endif #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) && \ defined(PNG_USER_TRANSFORM_PTR_SUPPORTED) if(png_ptr->transformations & PNG_USER_TRANSFORM) { 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; } #endif /* align the width on the next larger 8 pixels. Mainly used for interlacing */ row_bytes = ((png_ptr->width + 7) & ~((png_uint_32)7)); /* calculate the maximum bytes needed, adding a byte and a pixel for safety's sake */ row_bytes = ((row_bytes * (png_uint_32)max_pixel_depth + 7) >> 3) + 1 + ((max_pixel_depth + 7) >> 3); #ifdef PNG_MAX_MALLOC_64K if (row_bytes > (png_uint_32)65536L) png_error(png_ptr, "This image requires a row greater than 64KB"); #endif png_ptr->row_buf = (png_bytep)png_malloc(png_ptr, row_bytes); #ifdef PNG_MAX_MALLOC_64K if ((png_uint_32)png_ptr->rowbytes + 1 > (png_uint_32)65536L) png_error(png_ptr, "This image requires a row greater than 64KB"); #endif png_ptr->prev_row = (png_bytep)png_malloc(png_ptr, (png_uint_32)( png_ptr->rowbytes + 1)); png_memset_check(png_ptr, png_ptr->prev_row, 0, png_ptr->rowbytes + 1); png_debug1(3, "width = %d,\n", png_ptr->width); png_debug1(3, "height = %d,\n", png_ptr->height); png_debug1(3, "iwidth = %d,\n", png_ptr->iwidth); png_debug1(3, "num_rows = %d\n", png_ptr->num_rows); png_debug1(3, "rowbytes = %d,\n", png_ptr->rowbytes); png_debug1(3, "irowbytes = %d,\n", png_ptr->irowbytes); png_ptr->flags |= PNG_FLAG_ROW_INIT; }