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Diffstat (limited to 'plugingui/png/pngrutil.c')
| -rw-r--r-- | plugingui/png/pngrutil.c | 4159 |
1 files changed, 0 insertions, 4159 deletions
diff --git a/plugingui/png/pngrutil.c b/plugingui/png/pngrutil.c deleted file mode 100644 index bc79d5c..0000000 --- a/plugingui/png/pngrutil.c +++ /dev/null @@ -1,4159 +0,0 @@ - -/* pngrutil.c - utilities to read a PNG file - * - * 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.) - * - * This code is released under the libpng license. - * For conditions of distribution and use, see the disclaimer - * and license in png.h - * - * This file contains routines that are only called from within - * libpng itself during the course of reading an image. - */ - -#include "pngpriv.h" - -#ifdef PNG_READ_SUPPORTED - -#define png_strtod(p,a,b) strtod(a,b) - -png_uint_32 PNGAPI -png_get_uint_31(png_structp png_ptr, png_const_bytep buf) -{ - png_uint_32 uval = png_get_uint_32(buf); - - if (uval > PNG_UINT_31_MAX) - dg_png_error(png_ptr, "PNG unsigned integer out of range"); - - return (uval); -} - -#if defined(PNG_READ_gAMA_SUPPORTED) || defined(PNG_READ_cHRM_SUPPORTED) -/* The following is a variation on the above for use with the fixed - * point values used for gAMA and cHRM. Instead of png_error it - * issues a warning and returns (-1) - an invalid value because both - * gAMA and cHRM use *unsigned* integers for fixed point values. - */ -#define PNG_FIXED_ERROR (-1) - -static png_fixed_point /* PRIVATE */ -png_get_fixed_point(png_structp png_ptr, png_const_bytep buf) -{ - png_uint_32 uval = png_get_uint_32(buf); - - if (uval <= PNG_UINT_31_MAX) - return (png_fixed_point)uval; /* known to be in range */ - - /* The caller can turn off the warning by passing NULL. */ - if (png_ptr != NULL) - png_warning(png_ptr, "PNG fixed point integer out of range"); - - return PNG_FIXED_ERROR; -} -#endif - -#ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED -/* NOTE: the read macros will obscure these definitions, so that if - * PNG_USE_READ_MACROS is set the library will not use them internally, - * but the APIs will still be available externally. - * - * The parentheses around "PNGAPI function_name" in the following three - * functions are necessary because they allow the macros to co-exist with - * these (unused but exported) functions. - */ - -/* Grab an unsigned 32-bit integer from a buffer in big-endian format. */ -png_uint_32 (PNGAPI -png_get_uint_32)(png_const_bytep buf) -{ - png_uint_32 uval = - ((png_uint_32)(*(buf )) << 24) + - ((png_uint_32)(*(buf + 1)) << 16) + - ((png_uint_32)(*(buf + 2)) << 8) + - ((png_uint_32)(*(buf + 3)) ) ; - - return uval; -} - -/* 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 there - * is no guarantee that a 'png_int_32' is exactly 32 bits, therefore - * the following code does a two's complement to native conversion. - */ -png_int_32 (PNGAPI -png_get_int_32)(png_const_bytep buf) -{ - png_uint_32 uval = png_get_uint_32(buf); - if ((uval & 0x80000000) == 0) /* non-negative */ - return uval; - - uval = (uval ^ 0xffffffff) + 1; /* 2's complement: -x = ~x+1 */ - return -(png_int_32)uval; -} - -/* Grab an unsigned 16-bit integer from a buffer in big-endian format. */ -png_uint_16 (PNGAPI -png_get_uint_16)(png_const_bytep buf) -{ - /* ANSI-C requires an int value to accomodate at least 16 bits so this - * works and allows the compiler not to worry about possible narrowing - * on 32 bit systems. (Pre-ANSI systems did not make integers smaller - * than 16 bits either.) - */ - unsigned int val = - ((unsigned int)(*buf) << 8) + - ((unsigned int)(*(buf + 1))); - - return (png_uint_16)val; -} - -#endif /* PNG_READ_INT_FUNCTIONS_SUPPORTED */ - -/* Read and check the PNG file signature */ -void /* PRIVATE */ -png_read_sig(png_structp png_ptr, png_infop info_ptr) -{ - png_size_t num_checked, num_to_check; - - /* Exit if the user application does not expect a signature. */ - if (png_ptr->sig_bytes >= 8) - return; - - num_checked = png_ptr->sig_bytes; - num_to_check = 8 - num_checked; - -#ifdef PNG_IO_STATE_SUPPORTED - png_ptr->io_state = PNG_IO_READING | PNG_IO_SIGNATURE; -#endif - - /* The signature must be serialized in a single I/O call. */ - png_read_data(png_ptr, &(info_ptr->signature[num_checked]), num_to_check); - png_ptr->sig_bytes = 8; - - if (dg_png_sig_cmp(info_ptr->signature, num_checked, num_to_check)) - { - if (num_checked < 4 && - dg_png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4)) - dg_png_error(png_ptr, "Not a PNG file"); - else - dg_png_error(png_ptr, "PNG file corrupted by ASCII conversion"); - } - if (num_checked < 3) - png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE; -} - -/* Read the chunk header (length + type name). - * Put the type name into png_ptr->chunk_name, and return the length. - */ -png_uint_32 /* PRIVATE */ -png_read_chunk_header(png_structp png_ptr) -{ - png_byte buf[8]; - png_uint_32 length; - -#ifdef PNG_IO_STATE_SUPPORTED - png_ptr->io_state = PNG_IO_READING | PNG_IO_CHUNK_HDR; -#endif - - /* Read the length and the chunk name. - * This must be performed in a single I/O call. - */ - png_read_data(png_ptr, buf, 8); - length = png_get_uint_31(png_ptr, buf); - - /* Put the chunk name into png_ptr->chunk_name. */ - png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(buf+4); - - 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, buf + 4, 4); - - /* Check to see if chunk name is valid. */ - png_check_chunk_name(png_ptr, png_ptr->chunk_name); - -#ifdef PNG_IO_STATE_SUPPORTED - png_ptr->io_state = PNG_IO_READING | PNG_IO_CHUNK_DATA; -#endif - - return length; -} - -/* 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) -{ - if (png_ptr == NULL) - return; - - 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_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"); - } - - else - { - png_chunk_benign_error(png_ptr, "CRC error"); - return (0); - } - - 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_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 */ - { - if (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_IGNORE) - need_crc = 0; - } - -#ifdef PNG_IO_STATE_SUPPORTED - png_ptr->io_state = PNG_IO_READING | PNG_IO_CHUNK_CRC; -#endif - - /* The chunk CRC must be serialized in a single I/O call. */ - 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); -} - -#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) -{ - png_size_t count = 0; - - /* zlib can't necessarily handle more than 65535 bytes at once (i.e. it can't - * even necessarily handle 65536 bytes) because the type uInt is "16 bits or - * more". Consequently it is necessary to chunk the input to zlib. This - * code uses ZLIB_IO_MAX, from pngpriv.h, as the maximum (the maximum value - * that can be stored in a uInt.) It is possible to set ZLIB_IO_MAX to a - * lower value in pngpriv.h and this may sometimes have a performance - * advantage, because it forces access of the input data to be separated from - * at least some of the use by some period of time. - */ - png_ptr->zstream.next_in = data; - /* avail_in is set below from 'size' */ - png_ptr->zstream.avail_in = 0; - - while (1) - { - int ret, avail; - - /* 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 - * window save (memcpy of up to 32768 output bytes) every ZLIB_IO_MAX - * input bytes. - */ - if (png_ptr->zstream.avail_in == 0 && size > 0) - { - if (size <= ZLIB_IO_MAX) - { - /* The value is less than ZLIB_IO_MAX so the cast is safe: */ - png_ptr->zstream.avail_in = (uInt)size; - size = 0; - } - - else - { - png_ptr->zstream.avail_in = ZLIB_IO_MAX; - size -= ZLIB_IO_MAX; - } - } - - /* Reset the output buffer each time round - we empty it - * after every inflate call. - */ - png_ptr->zstream.next_out = png_ptr->zbuf; - png_ptr->zstream.avail_out = png_ptr->zbuf_size; - - ret = inflate(&png_ptr->zstream, Z_NO_FLUSH); - avail = png_ptr->zbuf_size - png_ptr->zstream.avail_out; - - /* First copy/count any new output - but only if we didn't - * get an error code. - */ - if ((ret == Z_OK || ret == Z_STREAM_END) && avail > 0) - { - png_size_t space = avail; /* > 0, see above */ - - if (output != 0 && output_size > count) - { - png_size_t copy = output_size - count; - - if (space < copy) - copy = space; - - png_memcpy(output + count, png_ptr->zbuf, copy); - } - count += space; - } - - if (ret == Z_OK) - continue; - - /* Termination conditions - always reset the zstream, it - * must be left in inflateInit state. - */ - png_ptr->zstream.avail_in = 0; - inflateReset(&png_ptr->zstream); - - if (ret == Z_STREAM_END) - return count; /* NOTE: may be zero. */ - - /* Now handle the error codes - the API always returns 0 - * and the error message is dumped into the uncompressed - * buffer if available. - */ -# ifdef PNG_WARNINGS_SUPPORTED - { - png_const_charp msg; - - if (png_ptr->zstream.msg != 0) - msg = png_ptr->zstream.msg; - - else switch (ret) - { - case Z_BUF_ERROR: - msg = "Buffer error in compressed datastream"; - break; - - case Z_DATA_ERROR: - msg = "Data error in compressed datastream"; - break; - - default: - msg = "Incomplete compressed datastream"; - break; - } - - png_chunk_warning(png_ptr, msg); - } -# endif - - /* 0 means an error - notice that this code simply ignores - * zero length compressed chunks as a result. - */ - return 0; - } -} - -/* - * 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). - */ -void /* PRIVATE */ -png_decompress_chunk(png_structp png_ptr, int comp_type, - png_size_t chunklength, - png_size_t prefix_size, png_size_t *newlength) -{ - /* The caller should guarantee this */ - if (prefix_size > chunklength) - { - /* The recovery is to delete the chunk. */ - png_warning(png_ptr, "invalid chunklength"); - prefix_size = 0; /* To delete everything */ - } - - else if (comp_type == PNG_COMPRESSION_TYPE_BASE) - { - png_size_t expanded_size = png_inflate(png_ptr, - (png_bytep)(png_ptr->chunkdata + prefix_size), - chunklength - prefix_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. - */ - 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 - || ((PNG_USER_CHUNK_MALLOC_MAX > 0) && - prefix_size + expanded_size >= PNG_USER_CHUNK_MALLOC_MAX - 1) -#endif - ) - png_warning(png_ptr, "Exceeded size limit while expanding chunk"); - - /* If the size is zero either there was an error and a message - * has already been output (warning) or the size really is zero - * and we have nothing to do - the code will exit through the - * error case below. - */ - else if (expanded_size > 0) - { - /* Success (maybe) - really uncompress the chunk. */ - png_size_t new_size = 0; - png_charp text = (png_charp)png_malloc_warn(png_ptr, - prefix_size + expanded_size + 1); - - if (text != NULL) - { - png_memcpy(text, png_ptr->chunkdata, prefix_size); - new_size = png_inflate(png_ptr, - (png_bytep)(png_ptr->chunkdata + prefix_size), - chunklength - prefix_size, - (png_bytep)(text + prefix_size), expanded_size); - text[prefix_size + expanded_size] = 0; /* just in case */ - - if (new_size == expanded_size) - { - png_free(png_ptr, png_ptr->chunkdata); - png_ptr->chunkdata = text; - *newlength = prefix_size + expanded_size; - return; /* The success return! */ - } - - png_warning(png_ptr, "png_inflate logic error"); - png_free(png_ptr, text); - } - - else - png_warning(png_ptr, "Not enough memory to decompress chunk"); - } - } - - else /* if (comp_type != PNG_COMPRESSION_TYPE_BASE) */ - { - PNG_WARNING_PARAMETERS(p) - png_warning_parameter_signed(p, 1, PNG_NUMBER_FORMAT_d, comp_type); - png_formatted_warning(png_ptr, p, "Unknown compression type @1"); - - /* The recovery is to simply drop the data. */ - } - - /* Generic error return - leave the prefix, delete the compressed - * data, reallocate the chunkdata to remove the potentially large - * amount of compressed data. - */ - { - png_charp text = (png_charp)png_malloc_warn(png_ptr, prefix_size + 1); - - if (text != NULL) - { - if (prefix_size > 0) - png_memcpy(text, png_ptr->chunkdata, prefix_size); - - png_free(png_ptr, png_ptr->chunkdata); - png_ptr->chunkdata = text; - - /* This is an extra zero in the 'uncompressed' part. */ - *(png_ptr->chunkdata + prefix_size) = 0x00; - } - /* Ignore a malloc error here - it is safe. */ - } - - *newlength = prefix_size; -} -#endif /* PNG_READ_COMPRESSED_TEXT_SUPPORTED */ - -/* 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"); - - if (png_ptr->mode & PNG_HAVE_IHDR) - dg_png_error(png_ptr, "Out of place IHDR"); - - /* Check the length */ - if (length != 13) - dg_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_31(png_ptr, buf); - height = png_get_uint_31(png_ptr, buf + 4); - bit_depth = buf[8]; - color_type = buf[9]; - compression_type = buf[10]; - filter_type = buf[11]; - interlace_type = buf[12]; - - /* 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; -#ifdef PNG_MNG_FEATURES_SUPPORTED - png_ptr->filter_type = (png_byte)filter_type; -#endif - png_ptr->compression_type = (png_byte)compression_type; - - /* Find number of channels */ - switch (png_ptr->color_type) - { - default: /* invalid, png_set_IHDR calls png_error */ - 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_ROWBYTES(png_ptr->pixel_depth, png_ptr->width); - png_debug1(3, "bit_depth = %d", png_ptr->bit_depth); - png_debug1(3, "channels = %d", png_ptr->channels); - png_debug1(3, "rowbytes = %lu", (unsigned long)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_color palette[PNG_MAX_PALETTE_LENGTH]; - int num, i; -#ifdef PNG_POINTER_INDEXING_SUPPORTED - png_colorp pal_ptr; -#endif - - png_debug(1, "in png_handle_PLTE"); - - if (!(png_ptr->mode & PNG_HAVE_IHDR)) - dg_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) - dg_png_error(png_ptr, "Duplicate PLTE chunk"); - - png_ptr->mode |= PNG_HAVE_PLTE; - - if (!(png_ptr->color_type&PNG_COLOR_MASK_COLOR)) - { - png_warning(png_ptr, - "Ignoring PLTE chunk in grayscale PNG"); - png_crc_finish(png_ptr, length); - return; - } - -#ifndef PNG_READ_OPT_PLTE_SUPPORTED - if (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE) - { - png_crc_finish(png_ptr, length); - return; - } -#endif - - if (length > 3*PNG_MAX_PALETTE_LENGTH || 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 - { - dg_png_error(png_ptr, "Invalid palette chunk"); - } - } - - num = (int)length / 3; - -#ifdef PNG_POINTER_INDEXING_SUPPORTED - 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. - */ -#ifndef PNG_READ_OPT_PLTE_SUPPORTED - if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) -#endif - { - png_crc_finish(png_ptr, 0); - } - -#ifndef 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_benign_error(png_ptr, "CRC error"); - } - - else - { - png_chunk_warning(png_ptr, "CRC error"); - 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_set_PLTE(png_ptr, info_ptr, palette, num); - -#ifdef 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"); - - if (!(png_ptr->mode & PNG_HAVE_IHDR) || !(png_ptr->mode & PNG_HAVE_IDAT)) - { - dg_png_error(png_ptr, "No image in file"); - } - - 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); - - PNG_UNUSED(info_ptr) /* Quiet compiler warnings about unused info_ptr */ -} - -#ifdef 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; - png_byte buf[4]; - - png_debug(1, "in png_handle_gAMA"); - - if (!(png_ptr->mode & PNG_HAVE_IHDR)) - dg_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"); - - if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_gAMA) -#ifdef 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_get_fixed_point(NULL, buf); - - /* Check for zero gamma or an error. */ - if (igamma <= 0) - { - png_warning(png_ptr, - "Ignoring gAMA chunk with out of range gamma"); - - return; - } - -# ifdef PNG_READ_sRGB_SUPPORTED - if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sRGB)) - { - if (PNG_OUT_OF_RANGE(igamma, 45500, 500)) - { - 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; - } - } -# endif /* PNG_READ_sRGB_SUPPORTED */ - -# ifdef PNG_READ_GAMMA_SUPPORTED - /* Gamma correction on read is supported. */ - png_ptr->gamma = igamma; -# endif - /* And set the 'info' structure members. */ - png_set_gAMA_fixed(png_ptr, info_ptr, igamma); -} -#endif - -#ifdef 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"); - - buf[0] = buf[1] = buf[2] = buf[3] = 0; - - if (!(png_ptr->mode & PNG_HAVE_IHDR)) - dg_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"); - } - - 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 || length > 4) - { - 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 - -#ifdef PNG_READ_cHRM_SUPPORTED -void /* PRIVATE */ -png_handle_cHRM(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) -{ - png_byte buf[32]; - png_fixed_point x_white, y_white, x_red, y_red, x_green, y_green, x_blue, - y_blue; - - png_debug(1, "in png_handle_cHRM"); - - if (!(png_ptr->mode & PNG_HAVE_IHDR)) - dg_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, "Out of place cHRM chunk"); - - if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM) -# ifdef 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, 32); - - if (png_crc_finish(png_ptr, 0)) - return; - - x_white = png_get_fixed_point(NULL, buf); - y_white = png_get_fixed_point(NULL, buf + 4); - x_red = png_get_fixed_point(NULL, buf + 8); - y_red = png_get_fixed_point(NULL, buf + 12); - x_green = png_get_fixed_point(NULL, buf + 16); - y_green = png_get_fixed_point(NULL, buf + 20); - x_blue = png_get_fixed_point(NULL, buf + 24); - y_blue = png_get_fixed_point(NULL, buf + 28); - - if (x_white == PNG_FIXED_ERROR || - y_white == PNG_FIXED_ERROR || - x_red == PNG_FIXED_ERROR || - y_red == PNG_FIXED_ERROR || - x_green == PNG_FIXED_ERROR || - y_green == PNG_FIXED_ERROR || - x_blue == PNG_FIXED_ERROR || - y_blue == PNG_FIXED_ERROR) - { - png_warning(png_ptr, "Ignoring cHRM chunk with negative chromaticities"); - return; - } - -#ifdef PNG_READ_sRGB_SUPPORTED - if ((info_ptr != NULL) && (info_ptr->valid & PNG_INFO_sRGB)) - { - if (PNG_OUT_OF_RANGE(x_white, 31270, 1000) || - PNG_OUT_OF_RANGE(y_white, 32900, 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, 60000, 1000) || - PNG_OUT_OF_RANGE(x_blue, 15000, 1000) || - PNG_OUT_OF_RANGE(y_blue, 6000, 1000)) - { - 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) - dg_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 - dg_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); -} -#endif - -#ifdef 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"); - - if (!(png_ptr->mode & PNG_HAVE_IHDR)) - dg_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"); - - 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 != NULL && (info_ptr->valid & PNG_INFO_gAMA)) - { - if (PNG_OUT_OF_RANGE(info_ptr->gamma, 45500, 500)) - { - 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 */ - -#ifdef PNG_READ_cHRM_SUPPORTED - 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, 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, 60000, 1000) || - PNG_OUT_OF_RANGE(info_ptr->x_blue, 15000, 1000) || - PNG_OUT_OF_RANGE(info_ptr->y_blue, 6000, 1000)) - { - png_warning(png_ptr, - "Ignoring incorrect cHRM value when sRGB is also present"); - } -#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 */ - -#ifdef 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_byte compression_type; - png_bytep pC; - png_charp profile; - png_uint_32 skip = 0; - png_uint_32 profile_size; - png_alloc_size_t profile_length; - png_size_t slength, prefix_length, data_length; - - png_debug(1, "in png_handle_iCCP"); - - if (!(png_ptr->mode & PNG_HAVE_IHDR)) - dg_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"); - - 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) - { - png_warning(png_ptr, "iCCP chunk too large to fit in memory"); - skip = length - (png_uint_32)65535L; - length = (png_uint_32)65535L; - } -#endif - - png_free(png_ptr, png_ptr->chunkdata); - png_ptr->chunkdata = (png_charp)png_malloc(png_ptr, length + 1); - slength = length; - png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength); - - if (png_crc_finish(png_ptr, skip)) - { - png_free(png_ptr, png_ptr->chunkdata); - png_ptr->chunkdata = NULL; - return; - } - - png_ptr->chunkdata[slength] = 0x00; - - for (profile = png_ptr->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 >= png_ptr->chunkdata + slength - 1) - { - png_free(png_ptr, png_ptr->chunkdata); - png_ptr->chunkdata = NULL; - png_warning(png_ptr, "Malformed iCCP chunk"); - return; - } - - /* Compression_type should always be zero */ - compression_type = *profile++; - - if (compression_type) - { - png_warning(png_ptr, "Ignoring nonzero compression type in iCCP chunk"); - compression_type = 0x00; /* Reset it to zero (libpng-1.0.6 through 1.0.8 - wrote nonzero) */ - } - - prefix_length = profile - png_ptr->chunkdata; - png_decompress_chunk(png_ptr, compression_type, - slength, prefix_length, &data_length); - - profile_length = data_length - prefix_length; - - if (prefix_length > data_length || profile_length < 4) - { - png_free(png_ptr, png_ptr->chunkdata); - png_ptr->chunkdata = NULL; - png_warning(png_ptr, "Profile size field missing from iCCP chunk"); - return; - } - - /* Check the profile_size recorded in the first 32 bits of the ICC profile */ - pC = (png_bytep)(png_ptr->chunkdata + prefix_length); - profile_size = ((*(pC )) << 24) | - ((*(pC + 1)) << 16) | - ((*(pC + 2)) << 8) | - ((*(pC + 3)) ); - - /* NOTE: the following guarantees that 'profile_length' fits into 32 bits, - * because profile_size is a 32 bit value. - */ - if (profile_size < profile_length) - profile_length = profile_size; - - /* 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; - - 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; - } - - png_set_iCCP(png_ptr, info_ptr, png_ptr->chunkdata, - compression_type, (png_bytep)png_ptr->chunkdata + prefix_length, - profile_size); - png_free(png_ptr, png_ptr->chunkdata); - png_ptr->chunkdata = NULL; -} -#endif /* PNG_READ_iCCP_SUPPORTED */ - -#ifdef 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 entry_start; - png_sPLT_t new_palette; - png_sPLT_entryp pp; - png_uint_32 data_length; - int entry_size, i; - png_uint_32 skip = 0; - png_size_t slength; - png_uint_32 dl; - png_size_t max_dl; - - png_debug(1, "in png_handle_sPLT"); - -#ifdef PNG_USER_LIMITS_SUPPORTED - - if (png_ptr->user_chunk_cache_max != 0) - { - if (png_ptr->user_chunk_cache_max == 1) - { - png_crc_finish(png_ptr, length); - return; - } - - if (--png_ptr->user_chunk_cache_max == 1) - { - png_warning(png_ptr, "No space in chunk cache for sPLT"); - png_crc_finish(png_ptr, length); - return; - } - } -#endif - - if (!(png_ptr->mode & PNG_HAVE_IHDR)) - dg_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 - - png_free(png_ptr, png_ptr->chunkdata); - png_ptr->chunkdata = (png_charp)png_malloc(png_ptr, length + 1); - - /* WARNING: this may break if size_t is less than 32 bits; it is assumed - * 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 = length; - png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength); - - if (png_crc_finish(png_ptr, skip)) - { - png_free(png_ptr, png_ptr->chunkdata); - png_ptr->chunkdata = NULL; - return; - } - - png_ptr->chunkdata[slength] = 0x00; - - for (entry_start = (png_bytep)png_ptr->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 > (png_bytep)png_ptr->chunkdata + slength - 2) - { - png_free(png_ptr, png_ptr->chunkdata); - png_ptr->chunkdata = NULL; - png_warning(png_ptr, "malformed sPLT chunk"); - return; - } - - new_palette.depth = *entry_start++; - entry_size = (new_palette.depth == 8 ? 6 : 10); - /* This must fit in a png_uint_32 because it is derived from the original - * chunk data length (and use 'length', not 'slength' here for clarity - - * they are guaranteed to be the same, see the tests above.) - */ - data_length = length - (png_uint_32)(entry_start - - (png_bytep)png_ptr->chunkdata); - - /* Integrity-check the data length */ - if (data_length % entry_size) - { - png_free(png_ptr, png_ptr->chunkdata); - png_ptr->chunkdata = NULL; - png_warning(png_ptr, "sPLT chunk has bad length"); - return; - } - - dl = (png_int_32)(data_length / entry_size); - max_dl = PNG_SIZE_MAX / png_sizeof(png_sPLT_entry); - - if (dl > max_dl) - { - png_warning(png_ptr, "sPLT chunk too long"); - return; - } - - new_palette.nentries = (png_int_32)(data_length / entry_size); - - new_palette.entries = (png_sPLT_entryp)png_malloc_warn( - png_ptr, new_palette.nentries * png_sizeof(png_sPLT_entry)); - - if (new_palette.entries == NULL) - { - png_warning(png_ptr, "sPLT chunk requires too much memory"); - return; - } - -#ifdef PNG_POINTER_INDEXING_SUPPORTED - for (i = 0; i < new_palette.nentries; i++) - { - 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[i].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_ptr->chunkdata; - - png_set_sPLT(png_ptr, info_ptr, &new_palette, 1); - - png_free(png_ptr, png_ptr->chunkdata); - png_ptr->chunkdata = NULL; - png_free(png_ptr, new_palette.entries); -} -#endif /* PNG_READ_sPLT_SUPPORTED */ - -#ifdef PNG_READ_tRNS_SUPPORTED -void /* PRIVATE */ -png_handle_tRNS(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) -{ - png_byte readbuf[PNG_MAX_PALETTE_LENGTH]; - - png_debug(1, "in png_handle_tRNS"); - - if (!(png_ptr->mode & PNG_HAVE_IHDR)) - dg_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_GRAY) - { - png_byte buf[2]; - - 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_color.gray = png_get_uint_16(buf); - } - - 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_color.red = png_get_uint_16(buf); - png_ptr->trans_color.green = png_get_uint_16(buf + 2); - png_ptr->trans_color.blue = png_get_uint_16(buf + 4); - } - - else 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"); - } - - if (length > (png_uint_32)png_ptr->num_palette || - length > PNG_MAX_PALETTE_LENGTH) - { - 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_crc_read(png_ptr, readbuf, (png_size_t)length); - png_ptr->num_trans = (png_uint_16)length; - } - - 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)) - { - png_ptr->num_trans = 0; - return; - } - - png_set_tRNS(png_ptr, info_ptr, readbuf, png_ptr->num_trans, - &(png_ptr->trans_color)); -} -#endif - -#ifdef 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_color_16 background; - - png_debug(1, "in png_handle_bKGD"); - - if (!(png_ptr->mode & PNG_HAVE_IHDR)) - dg_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) - { - background.index = buf[0]; - - if (info_ptr && info_ptr->num_palette) - { - if (buf[0] >= info_ptr->num_palette) - { - png_warning(png_ptr, "Incorrect bKGD chunk index value"); - return; - } - - 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; - } - - else - background.red = background.green = background.blue = 0; - - background.gray = 0; - } - - else if (!(png_ptr->color_type & PNG_COLOR_MASK_COLOR)) /* GRAY */ - { - background.index = 0; - background.red = - background.green = - background.blue = - background.gray = png_get_uint_16(buf); - } - - else - { - 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, &background); -} -#endif - -#ifdef PNG_READ_hIST_SUPPORTED -void /* PRIVATE */ -png_handle_hIST(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) -{ - unsigned int num, i; - png_uint_16 readbuf[PNG_MAX_PALETTE_LENGTH]; - - png_debug(1, "in png_handle_hIST"); - - if (!(png_ptr->mode & PNG_HAVE_IHDR)) - dg_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 > 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]; - - png_crc_read(png_ptr, buf, 2); - readbuf[i] = png_get_uint_16(buf); - } - - if (png_crc_finish(png_ptr, 0)) - return; - - png_set_hIST(png_ptr, info_ptr, readbuf); -} -#endif - -#ifdef 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"); - - if (!(png_ptr->mode & PNG_HAVE_IHDR)) - dg_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 - -#ifdef 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"); - - if (!(png_ptr->mode & PNG_HAVE_IHDR)) - dg_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 - -#ifdef PNG_READ_pCAL_SUPPORTED -/* Read the pCAL chunk (described in the PNG Extensions document) */ -void /* PRIVATE */ -png_handle_pCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) -{ - 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"); - - if (!(png_ptr->mode & PNG_HAVE_IHDR)) - dg_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 (%u bytes)", - length + 1); - png_free(png_ptr, png_ptr->chunkdata); - png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1); - - if (png_ptr->chunkdata == NULL) - { - png_warning(png_ptr, "No memory for pCAL purpose"); - return; - } - - slength = length; - png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength); - - if (png_crc_finish(png_ptr, 0)) - { - png_free(png_ptr, png_ptr->chunkdata); - png_ptr->chunkdata = NULL; - return; - } - - png_ptr->chunkdata[slength] = 0x00; /* Null terminate the last string */ - - png_debug(3, "Finding end of pCAL purpose string"); - for (buf = png_ptr->chunkdata; *buf; buf++) - /* Empty loop */ ; - - endptr = png_ptr->chunkdata + 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, png_ptr->chunkdata); - png_ptr->chunkdata = NULL; - return; - } - - png_debug(3, "Reading pCAL X0, X1, type, nparams, and units"); - 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"); - /* 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, png_ptr->chunkdata); - png_ptr->chunkdata = NULL; - 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"); - - params = (png_charpp)png_malloc_warn(png_ptr, - (png_size_t)(nparams * png_sizeof(png_charp))); - - if (params == NULL) - { - png_free(png_ptr, png_ptr->chunkdata); - png_ptr->chunkdata = NULL; - png_warning(png_ptr, "No memory for pCAL params"); - return; - } - - /* 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", i); - - for (params[i] = buf; buf <= endptr && *buf != 0x00; 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, png_ptr->chunkdata); - png_ptr->chunkdata = NULL; - png_free(png_ptr, params); - return; - } - } - - png_set_pCAL(png_ptr, info_ptr, png_ptr->chunkdata, X0, X1, type, nparams, - units, params); - - png_free(png_ptr, png_ptr->chunkdata); - png_ptr->chunkdata = NULL; - png_free(png_ptr, params); -} -#endif - -#ifdef 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_size_t slength, i; - int state; - - png_debug(1, "in png_handle_sCAL"); - - if (!(png_ptr->mode & PNG_HAVE_IHDR)) - dg_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; - } - - /* 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); - - png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1); - - if (png_ptr->chunkdata == NULL) - { - png_warning(png_ptr, "Out of memory while processing sCAL chunk"); - png_crc_finish(png_ptr, length); - return; - } - - slength = length; - png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength); - png_ptr->chunkdata[slength] = 0x00; /* Null terminate the last string */ - - if (png_crc_finish(png_ptr, 0)) - { - png_free(png_ptr, png_ptr->chunkdata); - png_ptr->chunkdata = NULL; - return; - } - - /* Validate the unit. */ - if (png_ptr->chunkdata[0] != 1 && png_ptr->chunkdata[0] != 2) - { - png_warning(png_ptr, "Invalid sCAL ignored: invalid unit"); - png_free(png_ptr, png_ptr->chunkdata); - png_ptr->chunkdata = NULL; - return; - } - - /* Validate the ASCII numbers, need two ASCII numbers separated by - * a '\0' and they need to fit exactly in the chunk data. - */ - i = 1; - state = 0; - - 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; - - 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], - png_ptr->chunkdata+1, png_ptr->chunkdata+heighti); - } - - /* Clean up - just free the temporarily allocated buffer. */ - png_free(png_ptr, png_ptr->chunkdata); - png_ptr->chunkdata = NULL; -} -#endif - -#ifdef 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"); - - if (!(png_ptr->mode & PNG_HAVE_IHDR)) - dg_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 - -#ifdef 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; - int ret; - - png_debug(1, "in png_handle_tEXt"); - -#ifdef PNG_USER_LIMITS_SUPPORTED - if (png_ptr->user_chunk_cache_max != 0) - { - if (png_ptr->user_chunk_cache_max == 1) - { - png_crc_finish(png_ptr, length); - return; - } - - if (--png_ptr->user_chunk_cache_max == 1) - { - png_warning(png_ptr, "No space in chunk cache for tEXt"); - png_crc_finish(png_ptr, length); - return; - } - } -#endif - - if (!(png_ptr->mode & PNG_HAVE_IHDR)) - dg_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 - - png_free(png_ptr, png_ptr->chunkdata); - - png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1); - - if (png_ptr->chunkdata == NULL) - { - png_warning(png_ptr, "No memory to process text chunk"); - return; - } - - slength = length; - png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength); - - if (png_crc_finish(png_ptr, skip)) - { - png_free(png_ptr, png_ptr->chunkdata); - png_ptr->chunkdata = NULL; - return; - } - - key = png_ptr->chunkdata; - - 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_warn(png_ptr, - png_sizeof(png_text)); - - if (text_ptr == NULL) - { - png_warning(png_ptr, "Not enough memory to process text chunk"); - png_free(png_ptr, png_ptr->chunkdata); - png_ptr->chunkdata = NULL; - return; - } - - text_ptr->compression = PNG_TEXT_COMPRESSION_NONE; - text_ptr->key = key; - text_ptr->lang = NULL; - text_ptr->lang_key = NULL; - text_ptr->itxt_length = 0; - text_ptr->text = text; - text_ptr->text_length = png_strlen(text); - - ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1); - - png_free(png_ptr, png_ptr->chunkdata); - png_ptr->chunkdata = NULL; - png_free(png_ptr, text_ptr); - - if (ret) - png_warning(png_ptr, "Insufficient memory to process text chunk"); -} -#endif - -#ifdef 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 text; - int comp_type; - int ret; - png_size_t slength, prefix_len, data_len; - - png_debug(1, "in png_handle_zTXt"); - -#ifdef PNG_USER_LIMITS_SUPPORTED - if (png_ptr->user_chunk_cache_max != 0) - { - if (png_ptr->user_chunk_cache_max == 1) - { - png_crc_finish(png_ptr, length); - return; - } - - if (--png_ptr->user_chunk_cache_max == 1) - { - png_warning(png_ptr, "No space in chunk cache for zTXt"); - png_crc_finish(png_ptr, length); - return; - } - } -#endif - - if (!(png_ptr->mode & PNG_HAVE_IHDR)) - dg_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 - - png_free(png_ptr, png_ptr->chunkdata); - png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1); - - if (png_ptr->chunkdata == NULL) - { - png_warning(png_ptr, "Out of memory processing zTXt chunk"); - return; - } - - slength = length; - png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength); - - if (png_crc_finish(png_ptr, 0)) - { - png_free(png_ptr, png_ptr->chunkdata); - png_ptr->chunkdata = NULL; - return; - } - - png_ptr->chunkdata[slength] = 0x00; - - for (text = png_ptr->chunkdata; *text; text++) - /* Empty loop */ ; - - /* zTXt must have some text after the chunkdataword */ - if (text >= png_ptr->chunkdata + slength - 2) - { - png_warning(png_ptr, "Truncated zTXt chunk"); - png_free(png_ptr, png_ptr->chunkdata); - png_ptr->chunkdata = NULL; - return; - } - - else - { - comp_type = *(++text); - - if (comp_type != PNG_TEXT_COMPRESSION_zTXt) - { - png_warning(png_ptr, "Unknown compression type in zTXt chunk"); - comp_type = PNG_TEXT_COMPRESSION_zTXt; - } - - text++; /* Skip the compression_method byte */ - } - - prefix_len = text - png_ptr->chunkdata; - - png_decompress_chunk(png_ptr, comp_type, - (png_size_t)length, prefix_len, &data_len); - - text_ptr = (png_textp)png_malloc_warn(png_ptr, - png_sizeof(png_text)); - - if (text_ptr == NULL) - { - png_warning(png_ptr, "Not enough memory to process zTXt chunk"); - png_free(png_ptr, png_ptr->chunkdata); - png_ptr->chunkdata = NULL; - return; - } - - text_ptr->compression = comp_type; - text_ptr->key = png_ptr->chunkdata; - text_ptr->lang = NULL; - text_ptr->lang_key = NULL; - text_ptr->itxt_length = 0; - text_ptr->text = png_ptr->chunkdata + prefix_len; - text_ptr->text_length = data_len; - - ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1); - - png_free(png_ptr, text_ptr); - png_free(png_ptr, png_ptr->chunkdata); - png_ptr->chunkdata = NULL; - - if (ret) - dg_png_error(png_ptr, "Insufficient memory to store zTXt chunk"); -} -#endif - -#ifdef 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 key, lang, text, lang_key; - int comp_flag; - int comp_type = 0; - int ret; - png_size_t slength, prefix_len, data_len; - - png_debug(1, "in png_handle_iTXt"); - -#ifdef PNG_USER_LIMITS_SUPPORTED - if (png_ptr->user_chunk_cache_max != 0) - { - if (png_ptr->user_chunk_cache_max == 1) - { - png_crc_finish(png_ptr, length); - return; - } - - if (--png_ptr->user_chunk_cache_max == 1) - { - png_warning(png_ptr, "No space in chunk cache for iTXt"); - png_crc_finish(png_ptr, length); - return; - } - } -#endif - - if (!(png_ptr->mode & PNG_HAVE_IHDR)) - dg_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 - - png_free(png_ptr, png_ptr->chunkdata); - png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1); - - if (png_ptr->chunkdata == NULL) - { - png_warning(png_ptr, "No memory to process iTXt chunk"); - return; - } - - slength = length; - png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength); - - if (png_crc_finish(png_ptr, 0)) - { - png_free(png_ptr, png_ptr->chunkdata); - png_ptr->chunkdata = NULL; - return; - } - - png_ptr->chunkdata[slength] = 0x00; - - for (lang = png_ptr->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 >= png_ptr->chunkdata + slength - 3) - { - png_warning(png_ptr, "Truncated iTXt chunk"); - png_free(png_ptr, png_ptr->chunkdata); - png_ptr->chunkdata = NULL; - return; - } - - else - { - comp_flag = *lang++; - comp_type = *lang++; - } - - if (comp_type || (comp_flag && comp_flag != PNG_TEXT_COMPRESSION_zTXt)) - { - png_warning(png_ptr, "Unknown iTXt compression type or method"); - png_free(png_ptr, png_ptr->chunkdata); - png_ptr->chunkdata = NULL; - return; - } - - for (lang_key = lang; *lang_key; lang_key++) - /* Empty loop */ ; - - lang_key++; /* Skip NUL separator */ - - if (lang_key >= png_ptr->chunkdata + slength) - { - png_warning(png_ptr, "Truncated iTXt chunk"); - png_free(png_ptr, png_ptr->chunkdata); - png_ptr->chunkdata = NULL; - return; - } - - for (text = lang_key; *text; text++) - /* Empty loop */ ; - - text++; /* Skip NUL separator */ - - if (text >= png_ptr->chunkdata + slength) - { - png_warning(png_ptr, "Malformed iTXt chunk"); - png_free(png_ptr, png_ptr->chunkdata); - png_ptr->chunkdata = NULL; - return; - } - - prefix_len = text - png_ptr->chunkdata; - - key=png_ptr->chunkdata; - - if (comp_flag) - png_decompress_chunk(png_ptr, comp_type, - (size_t)length, prefix_len, &data_len); - - else - data_len = png_strlen(png_ptr->chunkdata + prefix_len); - - text_ptr = (png_textp)png_malloc_warn(png_ptr, - png_sizeof(png_text)); - - if (text_ptr == NULL) - { - png_warning(png_ptr, "Not enough memory to process iTXt chunk"); - png_free(png_ptr, png_ptr->chunkdata); - png_ptr->chunkdata = NULL; - return; - } - - text_ptr->compression = (int)comp_flag + 1; - text_ptr->lang_key = png_ptr->chunkdata + (lang_key - key); - text_ptr->lang = png_ptr->chunkdata + (lang - key); - text_ptr->itxt_length = data_len; - text_ptr->text_length = 0; - text_ptr->key = png_ptr->chunkdata; - text_ptr->text = png_ptr->chunkdata + prefix_len; - - ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1); - - png_free(png_ptr, text_ptr); - png_free(png_ptr, png_ptr->chunkdata); - png_ptr->chunkdata = NULL; - - if (ret) - dg_png_error(png_ptr, "Insufficient memory to store iTXt chunk"); -} -#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"); - -#ifdef PNG_USER_LIMITS_SUPPORTED - if (png_ptr->user_chunk_cache_max != 0) - { - if (png_ptr->user_chunk_cache_max == 1) - { - png_crc_finish(png_ptr, length); - return; - } - - if (--png_ptr->user_chunk_cache_max == 1) - { - png_warning(png_ptr, "No space in chunk cache for unknown chunk"); - png_crc_finish(png_ptr, length); - return; - } - } -#endif - - if (png_ptr->mode & PNG_HAVE_IDAT) - { - if (png_ptr->chunk_name != png_IDAT) - png_ptr->mode |= PNG_AFTER_IDAT; - } - - if (PNG_CHUNK_CRITICAL(png_ptr->chunk_name)) - { -#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED - 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 -#endif - ) -#endif - png_chunk_error(png_ptr, "unknown critical chunk"); - } - -#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED - if ((png_ptr->flags & PNG_FLAG_KEEP_UNKNOWN_CHUNKS) -#ifdef PNG_READ_USER_CHUNKS_SUPPORTED - || (png_ptr->read_user_chunk_fn != NULL) -#endif - ) - { -#ifdef PNG_MAX_MALLOC_64K - if (length > 65535) - { - png_warning(png_ptr, "unknown chunk too large to fit in memory"); - skip = length - 65535; - length = 65535; - } -#endif - - /* 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) - png_ptr->unknown_chunk.data = NULL; - - else - { - png_ptr->unknown_chunk.data = (png_bytep)png_malloc(png_ptr, length); - png_crc_read(png_ptr, png_ptr->unknown_chunk.data, length); - } - -#ifdef PNG_READ_USER_CHUNKS_SUPPORTED - if (png_ptr->read_user_chunk_fn != NULL) - { - /* Callback to user unknown chunk handler */ - int ret; - - ret = (*(png_ptr->read_user_chunk_fn)) - (png_ptr, &png_ptr->unknown_chunk); - - if (ret < 0) - png_chunk_error(png_ptr, "error in user chunk"); - - if (ret == 0) - { - if (PNG_CHUNK_CRITICAL(png_ptr->chunk_name)) - { -#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED - if (png_chunk_unknown_handling(png_ptr, png_ptr->chunk_name) != - PNG_HANDLE_CHUNK_ALWAYS) -#endif - png_chunk_error(png_ptr, "unknown critical chunk"); - } - - png_set_unknown_chunks(png_ptr, info_ptr, - &png_ptr->unknown_chunk, 1); - } - } - - else -#endif - png_set_unknown_chunks(png_ptr, info_ptr, &png_ptr->unknown_chunk, 1); - - png_free(png_ptr, png_ptr->unknown_chunk.data); - png_ptr->unknown_chunk.data = NULL; - } - - else -#endif - skip = length; - - png_crc_finish(png_ptr, skip); - -#ifndef PNG_READ_USER_CHUNKS_SUPPORTED - PNG_UNUSED(info_ptr) /* 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. - */ - -/* 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_uint_32 chunk_name) -{ - int i; - - png_debug(1, "in png_check_chunk_name"); - - for (i=1; i<=4; ++i) - { - 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 'display' value; if 'display' is true then the whole row - * (dp) is filled from the start by replicating the available pixels. If - * 'display' is false only those pixels present in the pass are filled in. - */ -void /* PRIVATE */ -png_combine_row(png_structp png_ptr, png_bytep dp, int display) -{ - unsigned int pixel_depth = png_ptr->transformed_pixel_depth; - 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"); - - /* 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) - dg_png_error(png_ptr, "internal row logic error"); - - /* 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)) - dg_png_error(png_ptr, "internal row size calculation error"); - - /* Don't expect this to ever happen: */ - if (row_width == 0) - dg_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))) - { - /* 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) - { - /* 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] = - { - /* 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) - mask = MASK(pass, pixel_depth, display, 0); - - else -# 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 */ - { - if (m != 0xff) - *dp = (png_byte)((*dp & ~m) | (*sp & m)); - else - *dp = *sp; - } - - /* 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 */ - - row_width -= pixels_per_byte; - ++dp; - ++sp; - } - } - - else /* pixel_depth >= 8 */ - { - unsigned int bytes_to_copy, bytes_to_jump; - - /* Validate the depth - it must be a multiple of 8 */ - if (pixel_depth & 7) - dg_png_error(png_ptr, "invalid user transform pixel depth"); - - pixel_depth >>= 3; /* now in bytes */ - row_width *= pixel_depth; - - /* 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; - - row_width -= offset; - dp += offset; - sp += offset; - } - - /* Work out the bytes to copy. */ - if (display) - { - /* 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; - - /* But don't allow this number to exceed the actual row width. */ - if (bytes_to_copy > row_width) - bytes_to_copy = row_width; - } - - 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; - - if (row_width <= bytes_to_jump) - return; - - dp += bytes_to_jump; - sp += bytes_to_jump; - row_width -= bytes_to_jump; - } - - case 2: - /* There is a possibility of a partial copy at the end here; this - * slows the code down somewhat. - */ - do - { - dp[0] = sp[0], dp[1] = sp[1]; - - if (row_width <= bytes_to_jump) - return; - - sp += bytes_to_jump; - dp += bytes_to_jump; - row_width -= bytes_to_jump; - } - while (row_width > 1); - - /* And there can only be one byte left at this point: */ - *dp = *sp; - return; - - 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]; - - if (row_width <= bytes_to_jump) - return; - - sp += bytes_to_jump; - dp += bytes_to_jump; - row_width -= bytes_to_jump; - } - - 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) - { - /* 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 */ - - /* The true default - use a png_memcpy: */ - for (;;) - { - png_memcpy(dp, sp, bytes_to_copy); - - if (row_width <= bytes_to_jump) - return; - - sp += bytes_to_jump; - dp += bytes_to_jump; - row_width -= bytes_to_jump; - if (bytes_to_copy > row_width) - bytes_to_copy = row_width; - } - } - - /* NOT REACHED*/ - } /* pixel_depth >= 8 */ - - /* Here if pixel_depth < 8 to check 'end_ptr' below. */ - } - else -#endif - - /* 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)); - - /* 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_row_infop row_info, png_bytep row, int pass, - png_uint_32 transformations /* Because these may affect the byte layout */) -{ - /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ - /* Offset to next interlace block */ - 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) - { - 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; - -#ifdef 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; - -#ifdef 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]; - -#ifdef 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) & 0x0f); - 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 = PNG_ROWBYTES(row_info->pixel_depth, final_width); - } -#ifndef PNG_READ_PACKSWAP_SUPPORTED - PNG_UNUSED(transformations) /* Silence compiler warning */ -#endif -} -#endif /* PNG_READ_INTERLACING_SUPPORTED */ - -static void -png_read_filter_row_sub(png_row_infop row_info, png_bytep row, - png_const_bytep prev_row) -{ - png_size_t i; - png_size_t istop = row_info->rowbytes; - unsigned int bpp = (row_info->pixel_depth + 7) >> 3; - png_bytep rp = row + bpp; - - PNG_UNUSED(prev_row) - - for (i = bpp; i < istop; i++) - { - *rp = (png_byte)(((int)(*rp) + (int)(*(rp-bpp))) & 0xff); - rp++; - } -} - -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 = 0; i < istop; i++) - { - *rp = (png_byte)(((int)(*rp) + (int)(*pp++)) & 0xff); - rp++; - } -} - -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; - - 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++ + *(rp-bpp)) / 2 ) & 0xff); - - rp++; - } -} - -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; - - /* First pixel/byte */ - c = *prev_row++; - a = *row + c; - *row++ = (png_byte)a; - - /* Remainder */ - while (row < rp_end) - { - int b, pa, pb, pc, p; - - a &= 0xff; /* From previous iteration or start */ - b = *prev_row++; - - p = b - c; - pc = a - c; - -# ifdef PNG_USE_ABS - pa = abs(p); - pb = abs(pc); - pc = abs(p + pc); -# else - pa = p < 0 ? -p : p; - pb = pc < 0 ? -pc : pc; - pc = (p + pc) < 0 ? -(p + pc) : p + pc; -# endif - - /* Find the best predictor, the least of pa, pb, pc favoring the earlier - * ones in the case of a tie. - */ - if (pb < pa) pa = pb, a = b; - if (pc < pa) a = c; - - /* Calculate the current pixel in a, and move the previous row pixel to c - * for the next time round the loop - */ - c = b; - a += *row; - *row++ = (png_byte)a; - } -} - -static void -png_read_filter_row_paeth_multibyte_pixel(png_row_infop row_info, png_bytep row, - png_const_bytep prev_row) -{ - int bpp = (row_info->pixel_depth + 7) >> 3; - png_bytep rp_end = row + bpp; - - /* Process the first pixel in the row completely (this is the same as 'up' - * because there is only one candidate predictor for the first row). - */ - while (row < rp_end) - { - int a = *row + *prev_row++; - *row++ = (png_byte)a; - } - - /* 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; - } - } - - fclose(f); - - return have_cap; -} -#endif /* __linux__ */ - -static void -png_init_filter_functions_neon(png_structp pp, unsigned int bpp) -{ -#ifdef __linux__ - if (!png_have_hwcap(HWCAP_NEON)) - return; -#endif - - pp->read_filter[PNG_FILTER_VALUE_UP-1] = png_read_filter_row_up_neon; - - if (bpp == 3) - { - pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub3_neon; - pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg3_neon; - pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = - png_read_filter_row_paeth3_neon; - } - - else if (bpp == 4) - { - pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub4_neon; - pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg4_neon; - pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = - png_read_filter_row_paeth4_neon; - } -} -#endif /* PNG_ARM_NEON */ - -static void -png_init_filter_functions(png_structp pp) -{ - unsigned int bpp = (pp->pixel_depth + 7) >> 3; - - pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub; - pp->read_filter[PNG_FILTER_VALUE_UP-1] = png_read_filter_row_up; - pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg; - if (bpp == 1) - pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = - png_read_filter_row_paeth_1byte_pixel; - else - pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = - png_read_filter_row_paeth_multibyte_pixel; - -#ifdef PNG_ARM_NEON - png_init_filter_functions_neon(pp, bpp); -#endif -} - -void /* PRIVATE */ -png_read_filter_row(png_structp pp, png_row_infop row_info, png_bytep row, - png_const_bytep prev_row, int filter) -{ - if (pp->read_filter[0] == NULL) - png_init_filter_functions(pp); - if (filter > PNG_FILTER_VALUE_NONE && filter < PNG_FILTER_VALUE_LAST) - pp->read_filter[filter-1](row_info, row, prev_row); -} - -#ifdef PNG_SEQUENTIAL_READ_SUPPORTED -void /* PRIVATE */ -png_read_finish_row(png_structp png_ptr) -{ -#ifdef PNG_READ_INTERLACING_SUPPORTED - /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ - - /* Start of interlace block */ - static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; - - /* Offset to next interlace block */ - static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; - - /* Start of interlace block in the y direction */ - 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 */ - 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"); - png_ptr->row_number++; - if (png_ptr->row_number < png_ptr->num_rows) - return; - -#ifdef PNG_READ_INTERLACING_SUPPORTED - if (png_ptr->interlaced) - { - 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 - { - 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]; - - 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]; - } - - else /* if (png_ptr->transformations & PNG_INTERLACE) */ - break; /* libpng deinterlacing sees every row */ - - } while (png_ptr->num_rows == 0 || png_ptr->iwidth == 0); - - if (png_ptr->pass < 7) - return; - } -#endif /* PNG_READ_INTERLACING_SUPPORTED */ - - if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED)) - { - 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_crc_finish(png_ptr, 0); - png_ptr->idat_size = png_read_chunk_header(png_ptr); - if (png_ptr->chunk_name != png_IDAT) - dg_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_warning(png_ptr, "Extra compressed data"); - - png_ptr->mode |= PNG_AFTER_IDAT; - png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED; - break; - } - - if (ret != Z_OK) - dg_png_error(png_ptr, png_ptr->zstream.msg ? png_ptr->zstream.msg : - "Decompression Error"); - - if (!(png_ptr->zstream.avail_out)) - { - png_warning(png_ptr, "Extra compressed data"); - png_ptr->mode |= PNG_AFTER_IDAT; - png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED; - break; - } - - } - png_ptr->zstream.avail_out = 0; - } - - if (png_ptr->idat_size || png_ptr->zstream.avail_in) - png_warning(png_ptr, "Extra compression data"); - - inflateReset(&png_ptr->zstream); - - png_ptr->mode |= PNG_AFTER_IDAT; -} -#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */ - -void /* PRIVATE */ -png_read_start_row(png_structp png_ptr) -{ -#ifdef PNG_READ_INTERLACING_SUPPORTED - /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ - - /* Start of interlace block */ - static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; - - /* Offset to next interlace block */ - static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; - - /* Start of interlace block in the y direction */ - 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 */ - static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; -#endif - - int max_pixel_depth; - png_size_t row_bytes; - - 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) - { - 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]; - } - - else -#endif /* PNG_READ_INTERLACING_SUPPORTED */ - { - png_ptr->num_rows = png_ptr->height; - png_ptr->iwidth = png_ptr->width; - } - - max_pixel_depth = png_ptr->pixel_depth; - - /* WARNING: * png_read_transform_info (pngrtran.c) performs a simpliar set of - * calculations to calculate the final pixel depth, then - * png_do_read_transforms actually does the transforms. This means that the - * code which effectively calculates this value is actually repeated in three - * separate places. They must all match. Innocent changes to the order of - * transformations can and will break libpng in a way that causes memory - * overwrites. - * - * TODO: fix this. - */ -#ifdef PNG_READ_PACK_SUPPORTED - if ((png_ptr->transformations & PNG_PACK) && png_ptr->bit_depth < 8) - max_pixel_depth = 8; -#endif - -#ifdef 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 - -#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_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 || - png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) - { - if (max_pixel_depth <= 32) - max_pixel_depth = 32; - - else - max_pixel_depth = 64; - } - } -#endif - -#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED - if (png_ptr->transformations & PNG_GRAY_TO_RGB) - { - if ( -#ifdef PNG_READ_EXPAND_SUPPORTED - (png_ptr->num_trans && (png_ptr->transformations & PNG_EXPAND)) || -#endif -#ifdef 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 - - /* 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 - */ - 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 = PNG_ROWBYTES(max_pixel_depth, row_bytes) + - 1 + ((max_pixel_depth + 7) >> 3); - -#ifdef PNG_MAX_MALLOC_64K - if (row_bytes > (png_uint_32)65536L) - dg_png_error(png_ptr, "This image requires a row greater than 64KB"); -#endif - - 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_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; 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_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*/; - } - -#else - /* 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; - } - -#ifdef PNG_MAX_MALLOC_64K - if (png_ptr->rowbytes > 65535) - dg_png_error(png_ptr, "This image requires a row greater than 64KB"); - -#endif - if (png_ptr->rowbytes > (PNG_SIZE_MAX - 1)) - dg_png_error(png_ptr, "Row has too many bytes to allocate in memory"); - - png_memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1); - - png_debug1(3, "width = %u,", png_ptr->width); - png_debug1(3, "height = %u,", png_ptr->height); - png_debug1(3, "iwidth = %u,", png_ptr->iwidth); - png_debug1(3, "num_rows = %u,", png_ptr->num_rows); - png_debug1(3, "rowbytes = %lu,", (unsigned long)png_ptr->rowbytes); - png_debug1(3, "irowbytes = %lu", - (unsigned long)PNG_ROWBYTES(png_ptr->pixel_depth, png_ptr->iwidth) + 1); - - png_ptr->flags |= PNG_FLAG_ROW_INIT; -} -#endif /* PNG_READ_SUPPORTED */ |