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3001 lines
88 KiB
3001 lines
88 KiB
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/* pngrutil.c - utilities to read a PNG file |
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* |
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* libpng 1.2.1 - December 12, 2001 |
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* For conditions of distribution and use, see copyright notice in png.h |
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* Copyright (c) 1998-2001 Glenn Randers-Pehrson |
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* (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) |
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* (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) |
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* |
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* This file contains routines that are only called from within |
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* libpng itself during the course of reading an image. |
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*/ |
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|
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#define PNG_INTERNAL |
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#include "png.h" |
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|
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#if defined(_WIN32_WCE) |
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/* strtod() function is not supported on WindowsCE */ |
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# ifdef PNG_FLOATING_POINT_SUPPORTED |
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__inline double strtod(const char *nptr, char **endptr) |
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{ |
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double result = 0; |
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int len; |
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wchar_t *str, *end; |
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|
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len = MultiByteToWideChar(CP_ACP, 0, nptr, -1, NULL, 0); |
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str = (wchar_t *)malloc(len * sizeof(wchar_t)); |
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if ( NULL != str ) |
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{ |
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MultiByteToWideChar(CP_ACP, 0, nptr, -1, str, len); |
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result = wcstod(str, &end); |
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len = WideCharToMultiByte(CP_ACP, 0, end, -1, NULL, 0, NULL, NULL); |
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*endptr = (char *)nptr + (png_strlen(nptr) - len + 1); |
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free(str); |
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} |
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return result; |
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} |
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# endif |
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#endif |
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#ifndef PNG_READ_BIG_ENDIAN_SUPPORTED |
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/* Grab an unsigned 32-bit integer from a buffer in big-endian format. */ |
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png_uint_32 /* PRIVATE */ |
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png_get_uint_32(png_bytep buf) |
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{ |
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png_uint_32 i = ((png_uint_32)(*buf) << 24) + |
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((png_uint_32)(*(buf + 1)) << 16) + |
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((png_uint_32)(*(buf + 2)) << 8) + |
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(png_uint_32)(*(buf + 3)); |
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|
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return (i); |
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} |
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#if defined(PNG_READ_pCAL_SUPPORTED) || defined(PNG_READ_oFFs_SUPPORTED) |
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/* Grab a signed 32-bit integer from a buffer in big-endian format. The |
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* data is stored in the PNG file in two's complement format, and it is |
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* assumed that the machine format for signed integers is the same. */ |
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png_int_32 /* PRIVATE */ |
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png_get_int_32(png_bytep buf) |
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{ |
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png_int_32 i = ((png_int_32)(*buf) << 24) + |
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((png_int_32)(*(buf + 1)) << 16) + |
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((png_int_32)(*(buf + 2)) << 8) + |
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(png_int_32)(*(buf + 3)); |
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|
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return (i); |
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} |
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#endif /* PNG_READ_pCAL_SUPPORTED */ |
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|
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/* Grab an unsigned 16-bit integer from a buffer in big-endian format. */ |
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png_uint_16 /* PRIVATE */ |
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png_get_uint_16(png_bytep buf) |
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{ |
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png_uint_16 i = (png_uint_16)(((png_uint_16)(*buf) << 8) + |
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(png_uint_16)(*(buf + 1))); |
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|
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return (i); |
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} |
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#endif /* PNG_READ_BIG_ENDIAN_SUPPORTED */ |
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/* Read data, and (optionally) run it through the CRC. */ |
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void /* PRIVATE */ |
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png_crc_read(png_structp png_ptr, png_bytep buf, png_size_t length) |
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{ |
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png_read_data(png_ptr, buf, length); |
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png_calculate_crc(png_ptr, buf, length); |
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} |
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|
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/* Optionally skip data and then check the CRC. Depending on whether we |
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are reading a ancillary or critical chunk, and how the program has set |
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things up, we may calculate the CRC on the data and print a message. |
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Returns '1' if there was a CRC error, '0' otherwise. */ |
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int /* PRIVATE */ |
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png_crc_finish(png_structp png_ptr, png_uint_32 skip) |
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{ |
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png_size_t i; |
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png_size_t istop = png_ptr->zbuf_size; |
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|
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for (i = (png_size_t)skip; i > istop; i -= istop) |
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{ |
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png_crc_read(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size); |
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} |
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if (i) |
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{ |
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png_crc_read(png_ptr, png_ptr->zbuf, i); |
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} |
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|
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if (png_crc_error(png_ptr)) |
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{ |
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if (((png_ptr->chunk_name[0] & 0x20) && /* Ancillary */ |
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!(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN)) || |
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(!(png_ptr->chunk_name[0] & 0x20) && /* Critical */ |
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(png_ptr->flags & PNG_FLAG_CRC_CRITICAL_USE))) |
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{ |
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png_chunk_warning(png_ptr, "CRC error"); |
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} |
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else |
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{ |
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png_chunk_error(png_ptr, "CRC error"); |
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} |
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return (1); |
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} |
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|
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return (0); |
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} |
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|
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/* Compare the CRC stored in the PNG file with that calculated by libpng from |
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the data it has read thus far. */ |
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int /* PRIVATE */ |
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png_crc_error(png_structp png_ptr) |
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{ |
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png_byte crc_bytes[4]; |
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png_uint_32 crc; |
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int need_crc = 1; |
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|
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if (png_ptr->chunk_name[0] & 0x20) /* ancillary */ |
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{ |
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if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_MASK) == |
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(PNG_FLAG_CRC_ANCILLARY_USE | PNG_FLAG_CRC_ANCILLARY_NOWARN)) |
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need_crc = 0; |
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} |
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else /* critical */ |
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{ |
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if (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_IGNORE) |
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need_crc = 0; |
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} |
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png_read_data(png_ptr, crc_bytes, 4); |
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if (need_crc) |
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{ |
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crc = png_get_uint_32(crc_bytes); |
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return ((int)(crc != png_ptr->crc)); |
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} |
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else |
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return (0); |
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} |
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#if defined(PNG_READ_zTXt_SUPPORTED) || defined(PNG_READ_iTXt_SUPPORTED) || \ |
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defined(PNG_READ_iCCP_SUPPORTED) |
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/* |
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* Decompress trailing data in a chunk. The assumption is that chunkdata |
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* points at an allocated area holding the contents of a chunk with a |
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* trailing compressed part. What we get back is an allocated area |
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* holding the original prefix part and an uncompressed version of the |
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* trailing part (the malloc area passed in is freed). |
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*/ |
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png_charp /* PRIVATE */ |
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png_decompress_chunk(png_structp png_ptr, int comp_type, |
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png_charp chunkdata, png_size_t chunklength, |
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png_size_t prefix_size, png_size_t *newlength) |
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{ |
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static char msg[] = "Error decoding compressed text"; |
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png_charp text = NULL; |
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png_size_t text_size; |
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|
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if (comp_type == PNG_COMPRESSION_TYPE_BASE) |
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{ |
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int ret = Z_OK; |
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png_ptr->zstream.next_in = (png_bytep)(chunkdata + prefix_size); |
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png_ptr->zstream.avail_in = (uInt)(chunklength - prefix_size); |
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png_ptr->zstream.next_out = png_ptr->zbuf; |
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png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; |
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text_size = 0; |
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text = NULL; |
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while (png_ptr->zstream.avail_in) |
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{ |
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ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH); |
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if (ret != Z_OK && ret != Z_STREAM_END) |
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{ |
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if (png_ptr->zstream.msg != NULL) |
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png_warning(png_ptr, png_ptr->zstream.msg); |
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else |
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png_warning(png_ptr, msg); |
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inflateReset(&png_ptr->zstream); |
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png_ptr->zstream.avail_in = 0; |
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|
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if (text == NULL) |
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{ |
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text_size = prefix_size + sizeof(msg) + 1; |
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text = (png_charp)png_malloc(png_ptr, text_size); |
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png_memcpy(text, chunkdata, prefix_size); |
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} |
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text[text_size - 1] = 0x00; |
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|
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/* Copy what we can of the error message into the text chunk */ |
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text_size = (png_size_t)(chunklength - (text - chunkdata) - 1); |
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text_size = sizeof(msg) > text_size ? text_size : sizeof(msg); |
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png_memcpy(text + prefix_size, msg, text_size + 1); |
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break; |
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} |
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if (!png_ptr->zstream.avail_out || ret == Z_STREAM_END) |
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{ |
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if (text == NULL) |
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{ |
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text_size = prefix_size + |
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png_ptr->zbuf_size - png_ptr->zstream.avail_out; |
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text = (png_charp)png_malloc(png_ptr, text_size + 1); |
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png_memcpy(text + prefix_size, png_ptr->zbuf, |
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text_size - prefix_size); |
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png_memcpy(text, chunkdata, prefix_size); |
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*(text + text_size) = 0x00; |
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} |
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else |
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{ |
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png_charp tmp; |
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|
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tmp = text; |
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text = (png_charp)png_malloc(png_ptr, (png_uint_32)(text_size + |
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png_ptr->zbuf_size - png_ptr->zstream.avail_out + 1)); |
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png_memcpy(text, tmp, text_size); |
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png_free(png_ptr, tmp); |
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png_memcpy(text + text_size, png_ptr->zbuf, |
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(png_ptr->zbuf_size - png_ptr->zstream.avail_out)); |
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text_size += png_ptr->zbuf_size - png_ptr->zstream.avail_out; |
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*(text + text_size) = 0x00; |
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} |
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if (ret == Z_STREAM_END) |
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break; |
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else |
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{ |
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png_ptr->zstream.next_out = png_ptr->zbuf; |
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png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; |
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} |
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} |
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} |
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if (ret != Z_STREAM_END) |
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{ |
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#if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE) |
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char umsg[50]; |
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|
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if (ret == Z_BUF_ERROR) |
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sprintf(umsg,"Buffer error in compressed datastream in %s chunk", |
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png_ptr->chunk_name); |
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else if (ret == Z_DATA_ERROR) |
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sprintf(umsg,"Data error in compressed datastream in %s chunk", |
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png_ptr->chunk_name); |
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else |
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sprintf(umsg,"Incomplete compressed datastream in %s chunk", |
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png_ptr->chunk_name); |
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png_warning(png_ptr, umsg); |
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#else |
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png_warning(png_ptr, |
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"Incomplete compressed datastream in chunk other than IDAT"); |
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#endif |
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text_size=prefix_size; |
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if (text == NULL) |
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{ |
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text = (png_charp)png_malloc(png_ptr, text_size+1); |
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png_memcpy(text, chunkdata, prefix_size); |
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} |
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*(text + text_size) = 0x00; |
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} |
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inflateReset(&png_ptr->zstream); |
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png_ptr->zstream.avail_in = 0; |
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|
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png_free(png_ptr, chunkdata); |
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chunkdata = text; |
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*newlength=text_size; |
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} |
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else /* if (comp_type != PNG_COMPRESSION_TYPE_BASE) */ |
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{ |
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#if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE) |
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char umsg[50]; |
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|
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sprintf(umsg, "Unknown zTXt compression type %d", comp_type); |
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png_warning(png_ptr, umsg); |
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#else |
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png_warning(png_ptr, "Unknown zTXt compression type"); |
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#endif |
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*(chunkdata + prefix_size) = 0x00; |
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*newlength=prefix_size; |
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} |
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|
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return chunkdata; |
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} |
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#endif |
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|
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/* read and check the IDHR chunk */ |
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void /* PRIVATE */ |
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png_handle_IHDR(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) |
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{ |
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png_byte buf[13]; |
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png_uint_32 width, height; |
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int bit_depth, color_type, compression_type, filter_type; |
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int interlace_type; |
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png_debug(1, "in png_handle_IHDR\n"); |
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if (png_ptr->mode & PNG_HAVE_IHDR) |
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png_error(png_ptr, "Out of place IHDR"); |
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|
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/* check the length */ |
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if (length != 13) |
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png_error(png_ptr, "Invalid IHDR chunk"); |
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png_ptr->mode |= PNG_HAVE_IHDR; |
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|
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png_crc_read(png_ptr, buf, 13); |
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png_crc_finish(png_ptr, 0); |
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width = png_get_uint_32(buf); |
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height = png_get_uint_32(buf + 4); |
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bit_depth = buf[8]; |
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color_type = buf[9]; |
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compression_type = buf[10]; |
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filter_type = buf[11]; |
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interlace_type = buf[12]; |
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|
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|
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/* set internal variables */ |
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png_ptr->width = width; |
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png_ptr->height = height; |
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png_ptr->bit_depth = (png_byte)bit_depth; |
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png_ptr->interlaced = (png_byte)interlace_type; |
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png_ptr->color_type = (png_byte)color_type; |
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#if defined(PNG_MNG_FEATURES_SUPPORTED) |
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png_ptr->filter_type = (png_byte)filter_type; |
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#endif |
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|
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/* find number of channels */ |
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switch (png_ptr->color_type) |
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{ |
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case PNG_COLOR_TYPE_GRAY: |
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case PNG_COLOR_TYPE_PALETTE: |
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png_ptr->channels = 1; |
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break; |
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case PNG_COLOR_TYPE_RGB: |
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png_ptr->channels = 3; |
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break; |
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case PNG_COLOR_TYPE_GRAY_ALPHA: |
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png_ptr->channels = 2; |
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break; |
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case PNG_COLOR_TYPE_RGB_ALPHA: |
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png_ptr->channels = 4; |
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break; |
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} |
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|
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/* set up other useful info */ |
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png_ptr->pixel_depth = (png_byte)(png_ptr->bit_depth * |
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png_ptr->channels); |
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png_ptr->rowbytes = ((png_ptr->width * |
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(png_uint_32)png_ptr->pixel_depth + 7) >> 3); |
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png_debug1(3,"bit_depth = %d\n", png_ptr->bit_depth); |
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png_debug1(3,"channels = %d\n", png_ptr->channels); |
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png_debug1(3,"rowbytes = %lu\n", png_ptr->rowbytes); |
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png_set_IHDR(png_ptr, info_ptr, width, height, bit_depth, |
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color_type, interlace_type, compression_type, filter_type); |
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} |
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|
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/* read and check the palette */ |
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void /* PRIVATE */ |
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png_handle_PLTE(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) |
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{ |
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png_color palette[PNG_MAX_PALETTE_LENGTH]; |
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int num, i; |
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#ifndef PNG_NO_POINTER_INDEXING |
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png_colorp pal_ptr; |
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#endif |
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|
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png_debug(1, "in png_handle_PLTE\n"); |
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|
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if (!(png_ptr->mode & PNG_HAVE_IHDR)) |
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png_error(png_ptr, "Missing IHDR before PLTE"); |
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else if (png_ptr->mode & PNG_HAVE_IDAT) |
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{ |
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png_warning(png_ptr, "Invalid PLTE after IDAT"); |
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png_crc_finish(png_ptr, length); |
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return; |
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} |
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else if (png_ptr->mode & PNG_HAVE_PLTE) |
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png_error(png_ptr, "Duplicate PLTE chunk"); |
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|
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png_ptr->mode |= PNG_HAVE_PLTE; |
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|
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if (!(png_ptr->color_type&PNG_COLOR_MASK_COLOR)) |
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{ |
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png_warning(png_ptr, |
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"Ignoring PLTE chunk in grayscale PNG"); |
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png_crc_finish(png_ptr, length); |
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return; |
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} |
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#if !defined(PNG_READ_OPT_PLTE_SUPPORTED) |
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if (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE) |
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{ |
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png_crc_finish(png_ptr, length); |
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return; |
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} |
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#endif |
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|
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if (length > 3*PNG_MAX_PALETTE_LENGTH || length % 3) |
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{ |
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if (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE) |
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{ |
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png_warning(png_ptr, "Invalid palette chunk"); |
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png_crc_finish(png_ptr, length); |
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return; |
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} |
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else |
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{ |
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png_error(png_ptr, "Invalid palette chunk"); |
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} |
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} |
|
|
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num = (int)length / 3; |
|
|
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#ifndef PNG_NO_POINTER_INDEXING |
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for (i = 0, pal_ptr = palette; i < num; i++, pal_ptr++) |
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{ |
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png_byte buf[3]; |
|
|
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png_crc_read(png_ptr, buf, 3); |
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pal_ptr->red = buf[0]; |
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pal_ptr->green = buf[1]; |
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pal_ptr->blue = buf[2]; |
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} |
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#else |
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for (i = 0; i < num; i++) |
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{ |
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png_byte buf[3]; |
|
|
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png_crc_read(png_ptr, buf, 3); |
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/* don't depend upon png_color being any order */ |
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palette[i].red = buf[0]; |
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palette[i].green = buf[1]; |
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palette[i].blue = buf[2]; |
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} |
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#endif |
|
|
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/* If we actually NEED the PLTE chunk (ie for a paletted image), we do |
|
whatever the normal CRC configuration tells us. However, if we |
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have an RGB image, the PLTE can be considered ancillary, so |
|
we will act as though it is. */ |
|
#if !defined(PNG_READ_OPT_PLTE_SUPPORTED) |
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if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) |
|
#endif |
|
{ |
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png_crc_finish(png_ptr, 0); |
|
} |
|
#if !defined(PNG_READ_OPT_PLTE_SUPPORTED) |
|
else if (png_crc_error(png_ptr)) /* Only if we have a CRC error */ |
|
{ |
|
/* If we don't want to use the data from an ancillary chunk, |
|
we have two options: an error abort, or a warning and we |
|
ignore the data in this chunk (which should be OK, since |
|
it's considered ancillary for a RGB or RGBA image). */ |
|
if (!(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_USE)) |
|
{ |
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if (png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN) |
|
{ |
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png_chunk_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)) |
|
{ |
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png_chunk_warning(png_ptr, "CRC error"); |
|
} |
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} |
|
#endif |
|
|
|
png_set_PLTE(png_ptr, info_ptr, palette, num); |
|
|
|
#if defined(PNG_READ_tRNS_SUPPORTED) |
|
if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) |
|
{ |
|
if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS)) |
|
{ |
|
if (png_ptr->num_trans > (png_uint_16)num) |
|
{ |
|
png_warning(png_ptr, "Truncating incorrect tRNS chunk length"); |
|
png_ptr->num_trans = (png_uint_16)num; |
|
} |
|
if (info_ptr->num_trans > (png_uint_16)num) |
|
{ |
|
png_warning(png_ptr, "Truncating incorrect info tRNS chunk length"); |
|
info_ptr->num_trans = (png_uint_16)num; |
|
} |
|
} |
|
} |
|
#endif |
|
|
|
} |
|
|
|
void /* PRIVATE */ |
|
png_handle_IEND(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) |
|
{ |
|
png_debug(1, "in png_handle_IEND\n"); |
|
|
|
if (!(png_ptr->mode & PNG_HAVE_IHDR) || !(png_ptr->mode & PNG_HAVE_IDAT)) |
|
{ |
|
png_error(png_ptr, "No image in file"); |
|
|
|
info_ptr = info_ptr; /* quiet compiler warnings about unused info_ptr */ |
|
} |
|
|
|
png_ptr->mode |= (PNG_AFTER_IDAT | PNG_HAVE_IEND); |
|
|
|
if (length != 0) |
|
{ |
|
png_warning(png_ptr, "Incorrect IEND chunk length"); |
|
} |
|
png_crc_finish(png_ptr, length); |
|
} |
|
|
|
#if defined(PNG_READ_gAMA_SUPPORTED) |
|
void /* PRIVATE */ |
|
png_handle_gAMA(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) |
|
{ |
|
png_fixed_point igamma; |
|
#ifdef PNG_FLOATING_POINT_SUPPORTED |
|
float file_gamma; |
|
#endif |
|
png_byte buf[4]; |
|
|
|
png_debug(1, "in png_handle_gAMA\n"); |
|
|
|
if (!(png_ptr->mode & PNG_HAVE_IHDR)) |
|
png_error(png_ptr, "Missing IHDR before gAMA"); |
|
else if (png_ptr->mode & PNG_HAVE_IDAT) |
|
{ |
|
png_warning(png_ptr, "Invalid gAMA after IDAT"); |
|
png_crc_finish(png_ptr, length); |
|
return; |
|
} |
|
else if (png_ptr->mode & PNG_HAVE_PLTE) |
|
/* Should be an error, but we can cope with it */ |
|
png_warning(png_ptr, "Out of place gAMA chunk"); |
|
|
|
else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_gAMA) |
|
#if defined(PNG_READ_sRGB_SUPPORTED) |
|
&& !(info_ptr->valid & PNG_INFO_sRGB) |
|
#endif |
|
) |
|
{ |
|
png_warning(png_ptr, "Duplicate gAMA chunk"); |
|
png_crc_finish(png_ptr, length); |
|
return; |
|
} |
|
|
|
if (length != 4) |
|
{ |
|
png_warning(png_ptr, "Incorrect gAMA chunk length"); |
|
png_crc_finish(png_ptr, length); |
|
return; |
|
} |
|
|
|
png_crc_read(png_ptr, buf, 4); |
|
if (png_crc_finish(png_ptr, 0)) |
|
return; |
|
|
|
igamma = (png_fixed_point)png_get_uint_32(buf); |
|
/* check for zero gamma */ |
|
if (igamma == 0) |
|
{ |
|
png_warning(png_ptr, |
|
"Ignoring gAMA chunk with gamma=0"); |
|
return; |
|
} |
|
|
|
#if defined(PNG_READ_sRGB_SUPPORTED) |
|
if (info_ptr->valid & PNG_INFO_sRGB) |
|
if(igamma < 45000L || igamma > 46000L) |
|
{ |
|
png_warning(png_ptr, |
|
"Ignoring incorrect gAMA value when sRGB is also present"); |
|
#ifndef PNG_NO_CONSOLE_IO |
|
fprintf(stderr, "gamma = (%d/100000)\n", (int)igamma); |
|
#endif |
|
return; |
|
} |
|
#endif /* PNG_READ_sRGB_SUPPORTED */ |
|
|
|
#ifdef PNG_FLOATING_POINT_SUPPORTED |
|
file_gamma = (float)igamma / (float)100000.0; |
|
# ifdef PNG_READ_GAMMA_SUPPORTED |
|
png_ptr->gamma = file_gamma; |
|
# endif |
|
png_set_gAMA(png_ptr, info_ptr, file_gamma); |
|
#endif |
|
#ifdef PNG_FIXED_POINT_SUPPORTED |
|
png_set_gAMA_fixed(png_ptr, info_ptr, igamma); |
|
#endif |
|
} |
|
#endif |
|
|
|
#if defined(PNG_READ_sBIT_SUPPORTED) |
|
void /* PRIVATE */ |
|
png_handle_sBIT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) |
|
{ |
|
png_size_t truelen; |
|
png_byte buf[4]; |
|
|
|
png_debug(1, "in png_handle_sBIT\n"); |
|
|
|
buf[0] = buf[1] = buf[2] = buf[3] = 0; |
|
|
|
if (!(png_ptr->mode & PNG_HAVE_IHDR)) |
|
png_error(png_ptr, "Missing IHDR before sBIT"); |
|
else if (png_ptr->mode & PNG_HAVE_IDAT) |
|
{ |
|
png_warning(png_ptr, "Invalid sBIT after IDAT"); |
|
png_crc_finish(png_ptr, length); |
|
return; |
|
} |
|
else if (png_ptr->mode & PNG_HAVE_PLTE) |
|
{ |
|
/* Should be an error, but we can cope with it */ |
|
png_warning(png_ptr, "Out of place sBIT chunk"); |
|
} |
|
else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sBIT)) |
|
{ |
|
png_warning(png_ptr, "Duplicate sBIT chunk"); |
|
png_crc_finish(png_ptr, length); |
|
return; |
|
} |
|
|
|
if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) |
|
truelen = 3; |
|
else |
|
truelen = (png_size_t)png_ptr->channels; |
|
|
|
if (length != truelen) |
|
{ |
|
png_warning(png_ptr, "Incorrect sBIT chunk length"); |
|
png_crc_finish(png_ptr, length); |
|
return; |
|
} |
|
|
|
png_crc_read(png_ptr, buf, truelen); |
|
if (png_crc_finish(png_ptr, 0)) |
|
return; |
|
|
|
if (png_ptr->color_type & PNG_COLOR_MASK_COLOR) |
|
{ |
|
png_ptr->sig_bit.red = buf[0]; |
|
png_ptr->sig_bit.green = buf[1]; |
|
png_ptr->sig_bit.blue = buf[2]; |
|
png_ptr->sig_bit.alpha = buf[3]; |
|
} |
|
else |
|
{ |
|
png_ptr->sig_bit.gray = buf[0]; |
|
png_ptr->sig_bit.red = buf[0]; |
|
png_ptr->sig_bit.green = buf[0]; |
|
png_ptr->sig_bit.blue = buf[0]; |
|
png_ptr->sig_bit.alpha = buf[1]; |
|
} |
|
png_set_sBIT(png_ptr, info_ptr, &(png_ptr->sig_bit)); |
|
} |
|
#endif |
|
|
|
#if defined(PNG_READ_cHRM_SUPPORTED) |
|
void /* PRIVATE */ |
|
png_handle_cHRM(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) |
|
{ |
|
png_byte buf[4]; |
|
#ifdef PNG_FLOATING_POINT_SUPPORTED |
|
float white_x, white_y, red_x, red_y, green_x, green_y, blue_x, blue_y; |
|
#endif |
|
png_fixed_point int_x_white, int_y_white, int_x_red, int_y_red, int_x_green, |
|
int_y_green, int_x_blue, int_y_blue; |
|
|
|
png_debug(1, "in png_handle_cHRM\n"); |
|
|
|
if (!(png_ptr->mode & PNG_HAVE_IHDR)) |
|
png_error(png_ptr, "Missing IHDR before cHRM"); |
|
else if (png_ptr->mode & PNG_HAVE_IDAT) |
|
{ |
|
png_warning(png_ptr, "Invalid cHRM after IDAT"); |
|
png_crc_finish(png_ptr, length); |
|
return; |
|
} |
|
else if (png_ptr->mode & PNG_HAVE_PLTE) |
|
/* Should be an error, but we can cope with it */ |
|
png_warning(png_ptr, "Missing PLTE before cHRM"); |
|
|
|
else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM) |
|
#if defined(PNG_READ_sRGB_SUPPORTED) |
|
&& !(info_ptr->valid & PNG_INFO_sRGB) |
|
#endif |
|
) |
|
{ |
|
png_warning(png_ptr, "Duplicate cHRM chunk"); |
|
png_crc_finish(png_ptr, length); |
|
return; |
|
} |
|
|
|
if (length != 32) |
|
{ |
|
png_warning(png_ptr, "Incorrect cHRM chunk length"); |
|
png_crc_finish(png_ptr, length); |
|
return; |
|
} |
|
|
|
png_crc_read(png_ptr, buf, 4); |
|
int_x_white = (png_fixed_point)png_get_uint_32(buf); |
|
|
|
png_crc_read(png_ptr, buf, 4); |
|
int_y_white = (png_fixed_point)png_get_uint_32(buf); |
|
|
|
if (int_x_white > 80000L || int_y_white > 80000L || |
|
int_x_white + int_y_white > 100000L) |
|
{ |
|
png_warning(png_ptr, "Invalid cHRM white point"); |
|
png_crc_finish(png_ptr, 24); |
|
return; |
|
} |
|
|
|
png_crc_read(png_ptr, buf, 4); |
|
int_x_red = (png_fixed_point)png_get_uint_32(buf); |
|
|
|
png_crc_read(png_ptr, buf, 4); |
|
int_y_red = (png_fixed_point)png_get_uint_32(buf); |
|
|
|
if (int_x_red > 80000L || int_y_red > 80000L || |
|
int_x_red + int_y_red > 100000L) |
|
{ |
|
png_warning(png_ptr, "Invalid cHRM red point"); |
|
png_crc_finish(png_ptr, 16); |
|
return; |
|
} |
|
|
|
png_crc_read(png_ptr, buf, 4); |
|
int_x_green = (png_fixed_point)png_get_uint_32(buf); |
|
|
|
png_crc_read(png_ptr, buf, 4); |
|
int_y_green = (png_fixed_point)png_get_uint_32(buf); |
|
|
|
if (int_x_green > 80000L || int_y_green > 80000L || |
|
int_x_green + int_y_green > 100000L) |
|
{ |
|
png_warning(png_ptr, "Invalid cHRM green point"); |
|
png_crc_finish(png_ptr, 8); |
|
return; |
|
} |
|
|
|
png_crc_read(png_ptr, buf, 4); |
|
int_x_blue = (png_fixed_point)png_get_uint_32(buf); |
|
|
|
png_crc_read(png_ptr, buf, 4); |
|
int_y_blue = (png_fixed_point)png_get_uint_32(buf); |
|
|
|
if (int_x_blue > 80000L || int_y_blue > 80000L || |
|
int_x_blue + int_y_blue > 100000L) |
|
{ |
|
png_warning(png_ptr, "Invalid cHRM blue point"); |
|
png_crc_finish(png_ptr, 0); |
|
return; |
|
} |
|
#ifdef PNG_FLOATING_POINT_SUPPORTED |
|
white_x = (float)int_x_white / (float)100000.0; |
|
white_y = (float)int_y_white / (float)100000.0; |
|
red_x = (float)int_x_red / (float)100000.0; |
|
red_y = (float)int_y_red / (float)100000.0; |
|
green_x = (float)int_x_green / (float)100000.0; |
|
green_y = (float)int_y_green / (float)100000.0; |
|
blue_x = (float)int_x_blue / (float)100000.0; |
|
blue_y = (float)int_y_blue / (float)100000.0; |
|
#endif |
|
|
|
#if defined(PNG_READ_sRGB_SUPPORTED) |
|
if (info_ptr->valid & PNG_INFO_sRGB) |
|
{ |
|
if (abs(int_x_white - 31270L) > 1000 || |
|
abs(int_y_white - 32900L) > 1000 || |
|
abs(int_x_red - 64000L) > 1000 || |
|
abs(int_y_red - 33000L) > 1000 || |
|
abs(int_x_green - 30000L) > 1000 || |
|
abs(int_y_green - 60000L) > 1000 || |
|
abs(int_x_blue - 15000L) > 1000 || |
|
abs(int_y_blue - 6000L) > 1000) |
|
{ |
|
|
|
png_warning(png_ptr, |
|
"Ignoring incorrect cHRM value when sRGB is also present"); |
|
#ifndef PNG_NO_CONSOLE_IO |
|
#ifdef PNG_FLOATING_POINT_SUPPORTED |
|
fprintf(stderr,"wx=%f, wy=%f, rx=%f, ry=%f\n", |
|
white_x, white_y, red_x, red_y); |
|
fprintf(stderr,"gx=%f, gy=%f, bx=%f, by=%f\n", |
|
green_x, green_y, blue_x, blue_y); |
|
#else |
|
fprintf(stderr,"wx=%ld, wy=%ld, rx=%ld, ry=%ld\n", |
|
int_x_white, int_y_white, int_x_red, int_y_red); |
|
fprintf(stderr,"gx=%ld, gy=%ld, bx=%ld, by=%ld\n", |
|
int_x_green, int_y_green, int_x_blue, int_y_blue); |
|
#endif |
|
#endif /* PNG_NO_CONSOLE_IO */ |
|
} |
|
png_crc_finish(png_ptr, 0); |
|
return; |
|
} |
|
#endif /* PNG_READ_sRGB_SUPPORTED */ |
|
|
|
#ifdef PNG_FLOATING_POINT_SUPPORTED |
|
png_set_cHRM(png_ptr, info_ptr, |
|
white_x, white_y, red_x, red_y, green_x, green_y, blue_x, blue_y); |
|
#endif |
|
#ifdef PNG_FIXED_POINT_SUPPORTED |
|
png_set_cHRM_fixed(png_ptr, info_ptr, |
|
int_x_white, int_y_white, int_x_red, int_y_red, int_x_green, |
|
int_y_green, int_x_blue, int_y_blue); |
|
#endif |
|
if (png_crc_finish(png_ptr, 0)) |
|
return; |
|
} |
|
#endif |
|
|
|
#if defined(PNG_READ_sRGB_SUPPORTED) |
|
void /* PRIVATE */ |
|
png_handle_sRGB(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) |
|
{ |
|
int intent; |
|
png_byte buf[1]; |
|
|
|
png_debug(1, "in png_handle_sRGB\n"); |
|
|
|
if (!(png_ptr->mode & PNG_HAVE_IHDR)) |
|
png_error(png_ptr, "Missing IHDR before sRGB"); |
|
else if (png_ptr->mode & PNG_HAVE_IDAT) |
|
{ |
|
png_warning(png_ptr, "Invalid sRGB after IDAT"); |
|
png_crc_finish(png_ptr, length); |
|
return; |
|
} |
|
else if (png_ptr->mode & PNG_HAVE_PLTE) |
|
/* Should be an error, but we can cope with it */ |
|
png_warning(png_ptr, "Out of place sRGB chunk"); |
|
|
|
else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sRGB)) |
|
{ |
|
png_warning(png_ptr, "Duplicate sRGB chunk"); |
|
png_crc_finish(png_ptr, length); |
|
return; |
|
} |
|
|
|
if (length != 1) |
|
{ |
|
png_warning(png_ptr, "Incorrect sRGB chunk length"); |
|
png_crc_finish(png_ptr, length); |
|
return; |
|
} |
|
|
|
png_crc_read(png_ptr, buf, 1); |
|
if (png_crc_finish(png_ptr, 0)) |
|
return; |
|
|
|
intent = buf[0]; |
|
/* check for bad intent */ |
|
if (intent >= PNG_sRGB_INTENT_LAST) |
|
{ |
|
png_warning(png_ptr, "Unknown sRGB intent"); |
|
return; |
|
} |
|
|
|
#if defined(PNG_READ_gAMA_SUPPORTED) && defined(PNG_READ_GAMMA_SUPPORTED) |
|
if ((info_ptr->valid & PNG_INFO_gAMA)) |
|
{ |
|
int igamma; |
|
#ifdef PNG_FIXED_POINT_SUPPORTED |
|
igamma=(int)info_ptr->int_gamma; |
|
#else |
|
# ifdef PNG_FLOATING_POINT_SUPPORTED |
|
igamma=(int)(info_ptr->gamma * 100000.); |
|
# endif |
|
#endif |
|
#if 0 && defined(PNG_cHRM_SUPPORTED) && !defined(PNG_FIXED_POINT_SUPPORTED) |
|
/* We need to define these here because they aren't in png.h */ |
|
png_fixed_point int_x_white; |
|
png_fixed_point int_y_white; |
|
png_fixed_point int_x_red; |
|
png_fixed_point int_y_red; |
|
png_fixed_point int_x_green; |
|
png_fixed_point int_y_green; |
|
png_fixed_point int_x_blue; |
|
png_fixed_point int_y_blue; |
|
#endif |
|
if(igamma < 45000L || igamma > 46000L) |
|
{ |
|
png_warning(png_ptr, |
|
"Ignoring incorrect gAMA value when sRGB is also present"); |
|
#ifndef PNG_NO_CONSOLE_IO |
|
# ifdef PNG_FIXED_POINT_SUPPORTED |
|
fprintf(stderr,"incorrect gamma=(%d/100000)\n",(int)png_ptr->int_gamma); |
|
# else |
|
# ifdef PNG_FLOATING_POINT_SUPPORTED |
|
fprintf(stderr,"incorrect gamma=%f\n",png_ptr->gamma); |
|
# endif |
|
# endif |
|
#endif |
|
} |
|
} |
|
#endif /* PNG_READ_gAMA_SUPPORTED */ |
|
|
|
#ifdef PNG_READ_cHRM_SUPPORTED |
|
#ifdef PNG_FIXED_POINT_SUPPORTED |
|
if (info_ptr->valid & PNG_INFO_cHRM) |
|
if (abs(info_ptr->int_x_white - 31270L) > 1000 || |
|
abs(info_ptr->int_y_white - 32900L) > 1000 || |
|
abs(info_ptr->int_x_red - 64000L) > 1000 || |
|
abs(info_ptr->int_y_red - 33000L) > 1000 || |
|
abs(info_ptr->int_x_green - 30000L) > 1000 || |
|
abs(info_ptr->int_y_green - 60000L) > 1000 || |
|
abs(info_ptr->int_x_blue - 15000L) > 1000 || |
|
abs(info_ptr->int_y_blue - 6000L) > 1000) |
|
{ |
|
png_warning(png_ptr, |
|
"Ignoring incorrect cHRM value when sRGB is also present"); |
|
} |
|
#endif /* PNG_FIXED_POINT_SUPPORTED */ |
|
#endif /* PNG_READ_cHRM_SUPPORTED */ |
|
|
|
png_set_sRGB_gAMA_and_cHRM(png_ptr, info_ptr, intent); |
|
} |
|
#endif /* PNG_READ_sRGB_SUPPORTED */ |
|
|
|
#if defined(PNG_READ_iCCP_SUPPORTED) |
|
void /* PRIVATE */ |
|
png_handle_iCCP(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) |
|
/* Note: this does not properly handle chunks that are > 64K under DOS */ |
|
{ |
|
png_charp chunkdata; |
|
png_byte compression_type; |
|
png_charp profile; |
|
png_uint_32 skip = 0; |
|
png_uint_32 profile_size = 0; |
|
png_uint_32 profile_length = 0; |
|
png_size_t slength, prefix_length, data_length; |
|
|
|
png_debug(1, "in png_handle_iCCP\n"); |
|
|
|
if (!(png_ptr->mode & PNG_HAVE_IHDR)) |
|
png_error(png_ptr, "Missing IHDR before iCCP"); |
|
else if (png_ptr->mode & PNG_HAVE_IDAT) |
|
{ |
|
png_warning(png_ptr, "Invalid iCCP after IDAT"); |
|
png_crc_finish(png_ptr, length); |
|
return; |
|
} |
|
else if (png_ptr->mode & PNG_HAVE_PLTE) |
|
/* Should be an error, but we can cope with it */ |
|
png_warning(png_ptr, "Out of place iCCP chunk"); |
|
|
|
else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_iCCP)) |
|
{ |
|
png_warning(png_ptr, "Duplicate iCCP chunk"); |
|
png_crc_finish(png_ptr, length); |
|
return; |
|
} |
|
|
|
#ifdef PNG_MAX_MALLOC_64K |
|
if (length > (png_uint_32)65535L) |
|
{ |
|
png_warning(png_ptr, "iCCP chunk too large to fit in memory"); |
|
skip = length - (png_uint_32)65535L; |
|
length = (png_uint_32)65535L; |
|
} |
|
#endif |
|
|
|
chunkdata = (png_charp)png_malloc(png_ptr, length + 1); |
|
slength = (png_size_t)length; |
|
png_crc_read(png_ptr, (png_bytep)chunkdata, slength); |
|
|
|
if (png_crc_finish(png_ptr, skip)) |
|
{ |
|
png_free(png_ptr, chunkdata); |
|
return; |
|
} |
|
|
|
chunkdata[slength] = 0x00; |
|
|
|
for (profile = chunkdata; *profile; profile++) |
|
/* empty loop to find end of name */ ; |
|
|
|
++profile; |
|
|
|
/* there should be at least one zero (the compression type byte) |
|
following the separator, and we should be on it */ |
|
if ( profile >= chunkdata + slength) |
|
{ |
|
png_free(png_ptr, chunkdata); |
|
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 - chunkdata; |
|
chunkdata = png_decompress_chunk(png_ptr, compression_type, chunkdata, |
|
slength, prefix_length, &data_length); |
|
|
|
profile_length = data_length - prefix_length; |
|
|
|
if ( prefix_length > data_length || profile_length < 4) |
|
{ |
|
png_free(png_ptr, chunkdata); |
|
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 */ |
|
profile_size = ((*(chunkdata+prefix_length))<<24) | |
|
((*(chunkdata+prefix_length+1))<<16) | |
|
((*(chunkdata+prefix_length+2))<< 8) | |
|
((*(chunkdata+prefix_length+3)) ); |
|
|
|
if(profile_size < profile_length) |
|
profile_length = profile_size; |
|
|
|
if(profile_size > profile_length) |
|
{ |
|
png_free(png_ptr, chunkdata); |
|
png_warning(png_ptr, "Ignoring truncated iCCP profile.\n"); |
|
return; |
|
} |
|
|
|
png_set_iCCP(png_ptr, info_ptr, chunkdata, compression_type, |
|
chunkdata + prefix_length, profile_length); |
|
png_free(png_ptr, chunkdata); |
|
} |
|
#endif /* PNG_READ_iCCP_SUPPORTED */ |
|
|
|
#if defined(PNG_READ_sPLT_SUPPORTED) |
|
void /* PRIVATE */ |
|
png_handle_sPLT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) |
|
/* Note: this does not properly handle chunks that are > 64K under DOS */ |
|
{ |
|
png_bytep chunkdata; |
|
png_bytep entry_start; |
|
png_sPLT_t new_palette; |
|
#ifdef PNG_NO_POINTER_INDEXING |
|
png_sPLT_entryp pp; |
|
#endif |
|
int data_length, entry_size, i; |
|
png_uint_32 skip = 0; |
|
png_size_t slength; |
|
|
|
png_debug(1, "in png_handle_sPLT\n"); |
|
|
|
if (!(png_ptr->mode & PNG_HAVE_IHDR)) |
|
png_error(png_ptr, "Missing IHDR before sPLT"); |
|
else if (png_ptr->mode & PNG_HAVE_IDAT) |
|
{ |
|
png_warning(png_ptr, "Invalid sPLT after IDAT"); |
|
png_crc_finish(png_ptr, length); |
|
return; |
|
} |
|
|
|
#ifdef PNG_MAX_MALLOC_64K |
|
if (length > (png_uint_32)65535L) |
|
{ |
|
png_warning(png_ptr, "sPLT chunk too large to fit in memory"); |
|
skip = length - (png_uint_32)65535L; |
|
length = (png_uint_32)65535L; |
|
} |
|
#endif |
|
|
|
chunkdata = (png_bytep)png_malloc(png_ptr, length + 1); |
|
slength = (png_size_t)length; |
|
png_crc_read(png_ptr, (png_bytep)chunkdata, slength); |
|
|
|
if (png_crc_finish(png_ptr, skip)) |
|
{ |
|
png_free(png_ptr, chunkdata); |
|
return; |
|
} |
|
|
|
chunkdata[slength] = 0x00; |
|
|
|
for (entry_start = chunkdata; *entry_start; entry_start++) |
|
/* empty loop to find end of name */ ; |
|
++entry_start; |
|
|
|
/* a sample depth should follow the separator, and we should be on it */ |
|
if (entry_start > chunkdata + slength) |
|
{ |
|
png_free(png_ptr, chunkdata); |
|
png_warning(png_ptr, "malformed sPLT chunk"); |
|
return; |
|
} |
|
|
|
new_palette.depth = *entry_start++; |
|
entry_size = (new_palette.depth == 8 ? 6 : 10); |
|
data_length = (slength - (entry_start - chunkdata)); |
|
|
|
/* integrity-check the data length */ |
|
if (data_length % entry_size) |
|
{ |
|
png_free(png_ptr, chunkdata); |
|
png_warning(png_ptr, "sPLT chunk has bad length"); |
|
return; |
|
} |
|
|
|
new_palette.nentries = data_length / entry_size; |
|
new_palette.entries = (png_sPLT_entryp)png_malloc( |
|
png_ptr, new_palette.nentries * sizeof(png_sPLT_entry)); |
|
|
|
#ifndef PNG_NO_POINTER_INDEXING |
|
for (i = 0; i < new_palette.nentries; i++) |
|
{ |
|
png_sPLT_entryp pp = new_palette.entries + i; |
|
|
|
if (new_palette.depth == 8) |
|
{ |
|
pp->red = *entry_start++; |
|
pp->green = *entry_start++; |
|
pp->blue = *entry_start++; |
|
pp->alpha = *entry_start++; |
|
} |
|
else |
|
{ |
|
pp->red = png_get_uint_16(entry_start); entry_start += 2; |
|
pp->green = png_get_uint_16(entry_start); entry_start += 2; |
|
pp->blue = png_get_uint_16(entry_start); entry_start += 2; |
|
pp->alpha = png_get_uint_16(entry_start); entry_start += 2; |
|
} |
|
pp->frequency = png_get_uint_16(entry_start); entry_start += 2; |
|
} |
|
#else |
|
pp = new_palette.entries; |
|
for (i = 0; i < new_palette.nentries; i++) |
|
{ |
|
|
|
if (new_palette.depth == 8) |
|
{ |
|
pp[i].red = *entry_start++; |
|
pp[i].green = *entry_start++; |
|
pp[i].blue = *entry_start++; |
|
pp[i].alpha = *entry_start++; |
|
} |
|
else |
|
{ |
|
pp[i].red = png_get_uint_16(entry_start); entry_start += 2; |
|
pp[i].green = png_get_uint_16(entry_start); entry_start += 2; |
|
pp[i].blue = png_get_uint_16(entry_start); entry_start += 2; |
|
pp[i].alpha = png_get_uint_16(entry_start); entry_start += 2; |
|
} |
|
pp->frequency = png_get_uint_16(entry_start); entry_start += 2; |
|
} |
|
#endif |
|
|
|
/* discard all chunk data except the name and stash that */ |
|
new_palette.name = (png_charp)chunkdata; |
|
|
|
png_set_sPLT(png_ptr, info_ptr, &new_palette, 1); |
|
|
|
png_free(png_ptr, chunkdata); |
|
png_free(png_ptr, new_palette.entries); |
|
} |
|
#endif /* PNG_READ_sPLT_SUPPORTED */ |
|
|
|
#if defined(PNG_READ_tRNS_SUPPORTED) |
|
void /* PRIVATE */ |
|
png_handle_tRNS(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) |
|
{ |
|
png_byte readbuf[PNG_MAX_PALETTE_LENGTH]; |
|
|
|
png_debug(1, "in png_handle_tRNS\n"); |
|
|
|
if (!(png_ptr->mode & PNG_HAVE_IHDR)) |
|
png_error(png_ptr, "Missing IHDR before tRNS"); |
|
else if (png_ptr->mode & PNG_HAVE_IDAT) |
|
{ |
|
png_warning(png_ptr, "Invalid tRNS after IDAT"); |
|
png_crc_finish(png_ptr, length); |
|
return; |
|
} |
|
else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS)) |
|
{ |
|
png_warning(png_ptr, "Duplicate tRNS chunk"); |
|
png_crc_finish(png_ptr, length); |
|
return; |
|
} |
|
|
|
if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) |
|
{ |
|
if (!(png_ptr->mode & PNG_HAVE_PLTE)) |
|
{ |
|
/* Should be an error, but we can cope with it */ |
|
png_warning(png_ptr, "Missing PLTE before tRNS"); |
|
} |
|
else if (length > (png_uint_32)png_ptr->num_palette) |
|
{ |
|
png_warning(png_ptr, "Incorrect tRNS chunk length"); |
|
png_crc_finish(png_ptr, length); |
|
return; |
|
} |
|
if (length == 0) |
|
{ |
|
png_warning(png_ptr, "Zero length tRNS chunk"); |
|
png_crc_finish(png_ptr, length); |
|
return; |
|
} |
|
|
|
png_crc_read(png_ptr, readbuf, (png_size_t)length); |
|
png_ptr->num_trans = (png_uint_16)length; |
|
} |
|
else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB) |
|
{ |
|
png_byte buf[6]; |
|
|
|
if (length != 6) |
|
{ |
|
png_warning(png_ptr, "Incorrect tRNS chunk length"); |
|
png_crc_finish(png_ptr, length); |
|
return; |
|
} |
|
|
|
png_crc_read(png_ptr, buf, (png_size_t)length); |
|
png_ptr->num_trans = 1; |
|
png_ptr->trans_values.red = png_get_uint_16(buf); |
|
png_ptr->trans_values.green = png_get_uint_16(buf + 2); |
|
png_ptr->trans_values.blue = png_get_uint_16(buf + 4); |
|
} |
|
else if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY) |
|
{ |
|
png_byte buf[6]; |
|
|
|
if (length != 2) |
|
{ |
|
png_warning(png_ptr, "Incorrect tRNS chunk length"); |
|
png_crc_finish(png_ptr, length); |
|
return; |
|
} |
|
|
|
png_crc_read(png_ptr, buf, 2); |
|
png_ptr->num_trans = 1; |
|
png_ptr->trans_values.gray = png_get_uint_16(buf); |
|
} |
|
else |
|
{ |
|
png_warning(png_ptr, "tRNS chunk not allowed with alpha channel"); |
|
png_crc_finish(png_ptr, length); |
|
return; |
|
} |
|
|
|
if (png_crc_finish(png_ptr, 0)) |
|
return; |
|
|
|
png_set_tRNS(png_ptr, info_ptr, readbuf, png_ptr->num_trans, |
|
&(png_ptr->trans_values)); |
|
} |
|
#endif |
|
|
|
#if defined(PNG_READ_bKGD_SUPPORTED) |
|
void /* PRIVATE */ |
|
png_handle_bKGD(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) |
|
{ |
|
png_size_t truelen; |
|
png_byte buf[6]; |
|
|
|
png_debug(1, "in png_handle_bKGD\n"); |
|
|
|
if (!(png_ptr->mode & PNG_HAVE_IHDR)) |
|
png_error(png_ptr, "Missing IHDR before bKGD"); |
|
else if (png_ptr->mode & PNG_HAVE_IDAT) |
|
{ |
|
png_warning(png_ptr, "Invalid bKGD after IDAT"); |
|
png_crc_finish(png_ptr, length); |
|
return; |
|
} |
|
else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE && |
|
!(png_ptr->mode & PNG_HAVE_PLTE)) |
|
{ |
|
png_warning(png_ptr, "Missing PLTE before bKGD"); |
|
png_crc_finish(png_ptr, length); |
|
return; |
|
} |
|
else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_bKGD)) |
|
{ |
|
png_warning(png_ptr, "Duplicate bKGD chunk"); |
|
png_crc_finish(png_ptr, length); |
|
return; |
|
} |
|
|
|
if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) |
|
truelen = 1; |
|
else if (png_ptr->color_type & PNG_COLOR_MASK_COLOR) |
|
truelen = 6; |
|
else |
|
truelen = 2; |
|
|
|
if (length != truelen) |
|
{ |
|
png_warning(png_ptr, "Incorrect bKGD chunk length"); |
|
png_crc_finish(png_ptr, length); |
|
return; |
|
} |
|
|
|
png_crc_read(png_ptr, buf, truelen); |
|
if (png_crc_finish(png_ptr, 0)) |
|
return; |
|
|
|
/* We convert the index value into RGB components so that we can allow |
|
* arbitrary RGB values for background when we have transparency, and |
|
* so it is easy to determine the RGB values of the background color |
|
* from the info_ptr struct. */ |
|
if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) |
|
{ |
|
png_ptr->background.index = buf[0]; |
|
if(info_ptr->num_palette) |
|
{ |
|
if(buf[0] > info_ptr->num_palette) |
|
{ |
|
png_warning(png_ptr, "Incorrect bKGD chunk index value"); |
|
return; |
|
} |
|
png_ptr->background.red = |
|
(png_uint_16)png_ptr->palette[buf[0]].red; |
|
png_ptr->background.green = |
|
(png_uint_16)png_ptr->palette[buf[0]].green; |
|
png_ptr->background.blue = |
|
(png_uint_16)png_ptr->palette[buf[0]].blue; |
|
} |
|
} |
|
else if (!(png_ptr->color_type & PNG_COLOR_MASK_COLOR)) /* GRAY */ |
|
{ |
|
png_ptr->background.red = |
|
png_ptr->background.green = |
|
png_ptr->background.blue = |
|
png_ptr->background.gray = png_get_uint_16(buf); |
|
} |
|
else |
|
{ |
|
png_ptr->background.red = png_get_uint_16(buf); |
|
png_ptr->background.green = png_get_uint_16(buf + 2); |
|
png_ptr->background.blue = png_get_uint_16(buf + 4); |
|
} |
|
|
|
png_set_bKGD(png_ptr, info_ptr, &(png_ptr->background)); |
|
} |
|
#endif |
|
|
|
#if defined(PNG_READ_hIST_SUPPORTED) |
|
void /* PRIVATE */ |
|
png_handle_hIST(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) |
|
{ |
|
int num, i; |
|
png_uint_16 readbuf[PNG_MAX_PALETTE_LENGTH]; |
|
|
|
png_debug(1, "in png_handle_hIST\n"); |
|
|
|
if (!(png_ptr->mode & PNG_HAVE_IHDR)) |
|
png_error(png_ptr, "Missing IHDR before hIST"); |
|
else if (png_ptr->mode & PNG_HAVE_IDAT) |
|
{ |
|
png_warning(png_ptr, "Invalid hIST after IDAT"); |
|
png_crc_finish(png_ptr, length); |
|
return; |
|
} |
|
else if (!(png_ptr->mode & PNG_HAVE_PLTE)) |
|
{ |
|
png_warning(png_ptr, "Missing PLTE before hIST"); |
|
png_crc_finish(png_ptr, length); |
|
return; |
|
} |
|
else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_hIST)) |
|
{ |
|
png_warning(png_ptr, "Duplicate hIST chunk"); |
|
png_crc_finish(png_ptr, length); |
|
return; |
|
} |
|
|
|
num = (int)length / 2 ; |
|
if (num != png_ptr->num_palette) |
|
{ |
|
png_warning(png_ptr, "Incorrect hIST chunk length"); |
|
png_crc_finish(png_ptr, length); |
|
return; |
|
} |
|
|
|
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 |
|
|
|
#if defined(PNG_READ_pHYs_SUPPORTED) |
|
void /* PRIVATE */ |
|
png_handle_pHYs(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) |
|
{ |
|
png_byte buf[9]; |
|
png_uint_32 res_x, res_y; |
|
int unit_type; |
|
|
|
png_debug(1, "in png_handle_pHYs\n"); |
|
|
|
if (!(png_ptr->mode & PNG_HAVE_IHDR)) |
|
png_error(png_ptr, "Missing IHDR before pHYs"); |
|
else if (png_ptr->mode & PNG_HAVE_IDAT) |
|
{ |
|
png_warning(png_ptr, "Invalid pHYs after IDAT"); |
|
png_crc_finish(png_ptr, length); |
|
return; |
|
} |
|
else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs)) |
|
{ |
|
png_warning(png_ptr, "Duplicate pHYs chunk"); |
|
png_crc_finish(png_ptr, length); |
|
return; |
|
} |
|
|
|
if (length != 9) |
|
{ |
|
png_warning(png_ptr, "Incorrect pHYs chunk length"); |
|
png_crc_finish(png_ptr, length); |
|
return; |
|
} |
|
|
|
png_crc_read(png_ptr, buf, 9); |
|
if (png_crc_finish(png_ptr, 0)) |
|
return; |
|
|
|
res_x = png_get_uint_32(buf); |
|
res_y = png_get_uint_32(buf + 4); |
|
unit_type = buf[8]; |
|
png_set_pHYs(png_ptr, info_ptr, res_x, res_y, unit_type); |
|
} |
|
#endif |
|
|
|
#if defined(PNG_READ_oFFs_SUPPORTED) |
|
void /* PRIVATE */ |
|
png_handle_oFFs(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) |
|
{ |
|
png_byte buf[9]; |
|
png_int_32 offset_x, offset_y; |
|
int unit_type; |
|
|
|
png_debug(1, "in png_handle_oFFs\n"); |
|
|
|
if (!(png_ptr->mode & PNG_HAVE_IHDR)) |
|
png_error(png_ptr, "Missing IHDR before oFFs"); |
|
else if (png_ptr->mode & PNG_HAVE_IDAT) |
|
{ |
|
png_warning(png_ptr, "Invalid oFFs after IDAT"); |
|
png_crc_finish(png_ptr, length); |
|
return; |
|
} |
|
else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs)) |
|
{ |
|
png_warning(png_ptr, "Duplicate oFFs chunk"); |
|
png_crc_finish(png_ptr, length); |
|
return; |
|
} |
|
|
|
if (length != 9) |
|
{ |
|
png_warning(png_ptr, "Incorrect oFFs chunk length"); |
|
png_crc_finish(png_ptr, length); |
|
return; |
|
} |
|
|
|
png_crc_read(png_ptr, buf, 9); |
|
if (png_crc_finish(png_ptr, 0)) |
|
return; |
|
|
|
offset_x = png_get_int_32(buf); |
|
offset_y = png_get_int_32(buf + 4); |
|
unit_type = buf[8]; |
|
png_set_oFFs(png_ptr, info_ptr, offset_x, offset_y, unit_type); |
|
} |
|
#endif |
|
|
|
#if defined(PNG_READ_pCAL_SUPPORTED) |
|
/* read the pCAL chunk (described in the PNG Extensions document) */ |
|
void /* PRIVATE */ |
|
png_handle_pCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) |
|
{ |
|
png_charp purpose; |
|
png_int_32 X0, X1; |
|
png_byte type, nparams; |
|
png_charp buf, units, endptr; |
|
png_charpp params; |
|
png_size_t slength; |
|
int i; |
|
|
|
png_debug(1, "in png_handle_pCAL\n"); |
|
|
|
if (!(png_ptr->mode & PNG_HAVE_IHDR)) |
|
png_error(png_ptr, "Missing IHDR before pCAL"); |
|
else if (png_ptr->mode & PNG_HAVE_IDAT) |
|
{ |
|
png_warning(png_ptr, "Invalid pCAL after IDAT"); |
|
png_crc_finish(png_ptr, length); |
|
return; |
|
} |
|
else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_pCAL)) |
|
{ |
|
png_warning(png_ptr, "Duplicate pCAL chunk"); |
|
png_crc_finish(png_ptr, length); |
|
return; |
|
} |
|
|
|
png_debug1(2, "Allocating and reading pCAL chunk data (%lu bytes)\n", |
|
length + 1); |
|
purpose = (png_charp)png_malloc(png_ptr, length + 1); |
|
slength = (png_size_t)length; |
|
png_crc_read(png_ptr, (png_bytep)purpose, slength); |
|
|
|
if (png_crc_finish(png_ptr, 0)) |
|
{ |
|
png_free(png_ptr, purpose); |
|
return; |
|
} |
|
|
|
purpose[slength] = 0x00; /* null terminate the last string */ |
|
|
|
png_debug(3, "Finding end of pCAL purpose string\n"); |
|
for (buf = purpose; *buf; buf++) |
|
/* empty loop */ ; |
|
|
|
endptr = purpose + slength; |
|
|
|
/* We need to have at least 12 bytes after the purpose string |
|
in order to get the parameter information. */ |
|
if (endptr <= buf + 12) |
|
{ |
|
png_warning(png_ptr, "Invalid pCAL data"); |
|
png_free(png_ptr, purpose); |
|
return; |
|
} |
|
|
|
png_debug(3, "Reading pCAL X0, X1, type, nparams, and units\n"); |
|
X0 = png_get_int_32((png_bytep)buf+1); |
|
X1 = png_get_int_32((png_bytep)buf+5); |
|
type = buf[9]; |
|
nparams = buf[10]; |
|
units = buf + 11; |
|
|
|
png_debug(3, "Checking pCAL equation type and number of parameters\n"); |
|
/* Check that we have the right number of parameters for known |
|
equation types. */ |
|
if ((type == PNG_EQUATION_LINEAR && nparams != 2) || |
|
(type == PNG_EQUATION_BASE_E && nparams != 3) || |
|
(type == PNG_EQUATION_ARBITRARY && nparams != 3) || |
|
(type == PNG_EQUATION_HYPERBOLIC && nparams != 4)) |
|
{ |
|
png_warning(png_ptr, "Invalid pCAL parameters for equation type"); |
|
png_free(png_ptr, purpose); |
|
return; |
|
} |
|
else if (type >= PNG_EQUATION_LAST) |
|
{ |
|
png_warning(png_ptr, "Unrecognized equation type for pCAL chunk"); |
|
} |
|
|
|
for (buf = units; *buf; buf++) |
|
/* Empty loop to move past the units string. */ ; |
|
|
|
png_debug(3, "Allocating pCAL parameters array\n"); |
|
params = (png_charpp)png_malloc(png_ptr, (png_uint_32)(nparams |
|
*sizeof(png_charp))) ; |
|
|
|
/* Get pointers to the start of each parameter string. */ |
|
for (i = 0; i < (int)nparams; i++) |
|
{ |
|
buf++; /* Skip the null string terminator from previous parameter. */ |
|
|
|
png_debug1(3, "Reading pCAL parameter %d\n", i); |
|
for (params[i] = buf; *buf != 0x00 && buf <= endptr; buf++) |
|
/* Empty loop to move past each parameter string */ ; |
|
|
|
/* Make sure we haven't run out of data yet */ |
|
if (buf > endptr) |
|
{ |
|
png_warning(png_ptr, "Invalid pCAL data"); |
|
png_free(png_ptr, purpose); |
|
png_free(png_ptr, params); |
|
return; |
|
} |
|
} |
|
|
|
png_set_pCAL(png_ptr, info_ptr, purpose, X0, X1, type, nparams, |
|
units, params); |
|
|
|
png_free(png_ptr, purpose); |
|
png_free(png_ptr, params); |
|
} |
|
#endif |
|
|
|
#if defined(PNG_READ_sCAL_SUPPORTED) |
|
/* read the sCAL chunk */ |
|
void /* PRIVATE */ |
|
png_handle_sCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) |
|
{ |
|
png_charp buffer, ep; |
|
#ifdef PNG_FLOATING_POINT_SUPPORTED |
|
double width, height; |
|
png_charp vp; |
|
#else |
|
#ifdef PNG_FIXED_POINT_SUPPORTED |
|
png_charp swidth, sheight; |
|
#endif |
|
#endif |
|
png_size_t slength; |
|
|
|
png_debug(1, "in png_handle_sCAL\n"); |
|
|
|
if (!(png_ptr->mode & PNG_HAVE_IHDR)) |
|
png_error(png_ptr, "Missing IHDR before sCAL"); |
|
else if (png_ptr->mode & PNG_HAVE_IDAT) |
|
{ |
|
png_warning(png_ptr, "Invalid sCAL after IDAT"); |
|
png_crc_finish(png_ptr, length); |
|
return; |
|
} |
|
else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sCAL)) |
|
{ |
|
png_warning(png_ptr, "Duplicate sCAL chunk"); |
|
png_crc_finish(png_ptr, length); |
|
return; |
|
} |
|
|
|
png_debug1(2, "Allocating and reading sCAL chunk data (%lu bytes)\n", |
|
length + 1); |
|
buffer = (png_charp)png_malloc(png_ptr, length + 1); |
|
slength = (png_size_t)length; |
|
png_crc_read(png_ptr, (png_bytep)buffer, slength); |
|
|
|
if (png_crc_finish(png_ptr, 0)) |
|
{ |
|
png_free(png_ptr, buffer); |
|
return; |
|
} |
|
|
|
buffer[slength] = 0x00; /* null terminate the last string */ |
|
|
|
ep = buffer + 1; /* skip unit byte */ |
|
|
|
#ifdef PNG_FLOATING_POINT_SUPPORTED |
|
width = strtod(ep, &vp); |
|
if (*vp) |
|
{ |
|
png_warning(png_ptr, "malformed width string in sCAL chunk"); |
|
return; |
|
} |
|
#else |
|
#ifdef PNG_FIXED_POINT_SUPPORTED |
|
swidth = (png_charp)png_malloc(png_ptr, png_strlen(ep) + 1); |
|
png_memcpy(swidth, ep, (png_size_t)png_strlen(ep)); |
|
#endif |
|
#endif |
|
|
|
for (ep = buffer; *ep; ep++) |
|
/* empty loop */ ; |
|
ep++; |
|
|
|
#ifdef PNG_FLOATING_POINT_SUPPORTED |
|
height = strtod(ep, &vp); |
|
if (*vp) |
|
{ |
|
png_warning(png_ptr, "malformed height string in sCAL chunk"); |
|
return; |
|
} |
|
#else |
|
#ifdef PNG_FIXED_POINT_SUPPORTED |
|
sheight = (png_charp)png_malloc(png_ptr, png_strlen(ep) + 1); |
|
png_memcpy(sheight, ep, (png_size_t)png_strlen(ep)); |
|
#endif |
|
#endif |
|
|
|
if (buffer + slength < ep |
|
#ifdef PNG_FLOATING_POINT_SUPPORTED |
|
|| width <= 0. || height <= 0. |
|
#endif |
|
) |
|
{ |
|
png_warning(png_ptr, "Invalid sCAL data"); |
|
png_free(png_ptr, buffer); |
|
#if defined(PNG_FIXED_POINT_SUPPORTED) && !defined(PNG_FLOATING_POINT_SUPPORTED) |
|
png_free(png_ptr, swidth); |
|
png_free(png_ptr, sheight); |
|
#endif |
|
return; |
|
} |
|
|
|
|
|
#ifdef PNG_FLOATING_POINT_SUPPORTED |
|
png_set_sCAL(png_ptr, info_ptr, buffer[0], width, height); |
|
#else |
|
#ifdef PNG_FIXED_POINT_SUPPORTED |
|
png_set_sCAL_s(png_ptr, info_ptr, buffer[0], swidth, sheight); |
|
#endif |
|
#endif |
|
|
|
png_free(png_ptr, buffer); |
|
#if defined(PNG_FIXED_POINT_SUPPORTED) && !defined(PNG_FLOATING_POINT_SUPPORTED) |
|
png_free(png_ptr, swidth); |
|
png_free(png_ptr, sheight); |
|
#endif |
|
} |
|
#endif |
|
|
|
#if defined(PNG_READ_tIME_SUPPORTED) |
|
void /* PRIVATE */ |
|
png_handle_tIME(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) |
|
{ |
|
png_byte buf[7]; |
|
png_time mod_time; |
|
|
|
png_debug(1, "in png_handle_tIME\n"); |
|
|
|
if (!(png_ptr->mode & PNG_HAVE_IHDR)) |
|
png_error(png_ptr, "Out of place tIME chunk"); |
|
else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tIME)) |
|
{ |
|
png_warning(png_ptr, "Duplicate tIME chunk"); |
|
png_crc_finish(png_ptr, length); |
|
return; |
|
} |
|
|
|
if (png_ptr->mode & PNG_HAVE_IDAT) |
|
png_ptr->mode |= PNG_AFTER_IDAT; |
|
|
|
if (length != 7) |
|
{ |
|
png_warning(png_ptr, "Incorrect tIME chunk length"); |
|
png_crc_finish(png_ptr, length); |
|
return; |
|
} |
|
|
|
png_crc_read(png_ptr, buf, 7); |
|
if (png_crc_finish(png_ptr, 0)) |
|
return; |
|
|
|
mod_time.second = buf[6]; |
|
mod_time.minute = buf[5]; |
|
mod_time.hour = buf[4]; |
|
mod_time.day = buf[3]; |
|
mod_time.month = buf[2]; |
|
mod_time.year = png_get_uint_16(buf); |
|
|
|
png_set_tIME(png_ptr, info_ptr, &mod_time); |
|
} |
|
#endif |
|
|
|
#if defined(PNG_READ_tEXt_SUPPORTED) |
|
/* Note: this does not properly handle chunks that are > 64K under DOS */ |
|
void /* PRIVATE */ |
|
png_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) |
|
{ |
|
png_textp text_ptr; |
|
png_charp key; |
|
png_charp text; |
|
png_uint_32 skip = 0; |
|
png_size_t slength; |
|
|
|
png_debug(1, "in png_handle_tEXt\n"); |
|
|
|
if (!(png_ptr->mode & PNG_HAVE_IHDR)) |
|
png_error(png_ptr, "Missing IHDR before tEXt"); |
|
|
|
if (png_ptr->mode & PNG_HAVE_IDAT) |
|
png_ptr->mode |= PNG_AFTER_IDAT; |
|
|
|
#ifdef PNG_MAX_MALLOC_64K |
|
if (length > (png_uint_32)65535L) |
|
{ |
|
png_warning(png_ptr, "tEXt chunk too large to fit in memory"); |
|
skip = length - (png_uint_32)65535L; |
|
length = (png_uint_32)65535L; |
|
} |
|
#endif |
|
|
|
key = (png_charp)png_malloc(png_ptr, length + 1); |
|
slength = (png_size_t)length; |
|
png_crc_read(png_ptr, (png_bytep)key, slength); |
|
|
|
if (png_crc_finish(png_ptr, skip)) |
|
{ |
|
png_free(png_ptr, key); |
|
return; |
|
} |
|
|
|
key[slength] = 0x00; |
|
|
|
for (text = key; *text; text++) |
|
/* empty loop to find end of key */ ; |
|
|
|
if (text != key + slength) |
|
text++; |
|
|
|
text_ptr = (png_textp)png_malloc(png_ptr, (png_uint_32)sizeof(png_text)); |
|
text_ptr->compression = PNG_TEXT_COMPRESSION_NONE; |
|
text_ptr->key = key; |
|
#ifdef PNG_iTXt_SUPPORTED |
|
text_ptr->lang = NULL; |
|
text_ptr->lang_key = NULL; |
|
text_ptr->itxt_length = 0; |
|
#endif |
|
text_ptr->text = text; |
|
text_ptr->text_length = png_strlen(text); |
|
|
|
png_set_text(png_ptr, info_ptr, text_ptr, 1); |
|
|
|
png_free(png_ptr, key); |
|
png_free(png_ptr, text_ptr); |
|
} |
|
#endif |
|
|
|
#if defined(PNG_READ_zTXt_SUPPORTED) |
|
/* note: this does not correctly handle chunks that are > 64K under DOS */ |
|
void /* PRIVATE */ |
|
png_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) |
|
{ |
|
png_textp text_ptr; |
|
png_charp chunkdata; |
|
png_charp text; |
|
int comp_type; |
|
png_size_t slength, prefix_len, data_len; |
|
|
|
png_debug(1, "in png_handle_zTXt\n"); |
|
if (!(png_ptr->mode & PNG_HAVE_IHDR)) |
|
png_error(png_ptr, "Missing IHDR before zTXt"); |
|
|
|
if (png_ptr->mode & PNG_HAVE_IDAT) |
|
png_ptr->mode |= PNG_AFTER_IDAT; |
|
|
|
#ifdef PNG_MAX_MALLOC_64K |
|
/* We will no doubt have problems with chunks even half this size, but |
|
there is no hard and fast rule to tell us where to stop. */ |
|
if (length > (png_uint_32)65535L) |
|
{ |
|
png_warning(png_ptr,"zTXt chunk too large to fit in memory"); |
|
png_crc_finish(png_ptr, length); |
|
return; |
|
} |
|
#endif |
|
|
|
chunkdata = (png_charp)png_malloc(png_ptr, length + 1); |
|
slength = (png_size_t)length; |
|
png_crc_read(png_ptr, (png_bytep)chunkdata, slength); |
|
if (png_crc_finish(png_ptr, 0)) |
|
{ |
|
png_free(png_ptr, chunkdata); |
|
return; |
|
} |
|
|
|
chunkdata[slength] = 0x00; |
|
|
|
for (text = chunkdata; *text; text++) |
|
/* empty loop */ ; |
|
|
|
/* zTXt must have some text after the chunkdataword */ |
|
if (text == chunkdata + slength) |
|
{ |
|
comp_type = PNG_TEXT_COMPRESSION_NONE; |
|
png_warning(png_ptr, "Zero length zTXt chunk"); |
|
} |
|
else |
|
{ |
|
comp_type = *(++text); |
|
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 - chunkdata; |
|
|
|
chunkdata = (png_charp)png_decompress_chunk(png_ptr, comp_type, chunkdata, |
|
(png_size_t)length, prefix_len, &data_len); |
|
|
|
text_ptr = (png_textp)png_malloc(png_ptr, (png_uint_32)sizeof(png_text)); |
|
text_ptr->compression = comp_type; |
|
text_ptr->key = chunkdata; |
|
#ifdef PNG_iTXt_SUPPORTED |
|
text_ptr->lang = NULL; |
|
text_ptr->lang_key = NULL; |
|
text_ptr->itxt_length = 0; |
|
#endif |
|
text_ptr->text = chunkdata + prefix_len; |
|
text_ptr->text_length = data_len; |
|
|
|
png_set_text(png_ptr, info_ptr, text_ptr, 1); |
|
|
|
png_free(png_ptr, text_ptr); |
|
png_free(png_ptr, chunkdata); |
|
} |
|
#endif |
|
|
|
#if defined(PNG_READ_iTXt_SUPPORTED) |
|
/* note: this does not correctly handle chunks that are > 64K under DOS */ |
|
void /* PRIVATE */ |
|
png_handle_iTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) |
|
{ |
|
png_textp text_ptr; |
|
png_charp chunkdata; |
|
png_charp key, lang, text, lang_key; |
|
int comp_flag; |
|
int comp_type = 0; |
|
png_size_t slength, prefix_len, data_len; |
|
|
|
png_debug(1, "in png_handle_iTXt\n"); |
|
|
|
if (!(png_ptr->mode & PNG_HAVE_IHDR)) |
|
png_error(png_ptr, "Missing IHDR before iTXt"); |
|
|
|
if (png_ptr->mode & PNG_HAVE_IDAT) |
|
png_ptr->mode |= PNG_AFTER_IDAT; |
|
|
|
#ifdef PNG_MAX_MALLOC_64K |
|
/* We will no doubt have problems with chunks even half this size, but |
|
there is no hard and fast rule to tell us where to stop. */ |
|
if (length > (png_uint_32)65535L) |
|
{ |
|
png_warning(png_ptr,"iTXt chunk too large to fit in memory"); |
|
png_crc_finish(png_ptr, length); |
|
return; |
|
} |
|
#endif |
|
|
|
chunkdata = (png_charp)png_malloc(png_ptr, length + 1); |
|
slength = (png_size_t)length; |
|
png_crc_read(png_ptr, (png_bytep)chunkdata, slength); |
|
if (png_crc_finish(png_ptr, 0)) |
|
{ |
|
png_free(png_ptr, chunkdata); |
|
return; |
|
} |
|
|
|
chunkdata[slength] = 0x00; |
|
|
|
for (lang = chunkdata; *lang; lang++) |
|
/* empty loop */ ; |
|
lang++; /* skip NUL separator */ |
|
|
|
/* iTXt must have a language tag (possibly empty), two compression bytes, |
|
translated keyword (possibly empty), and possibly some text after the |
|
keyword */ |
|
|
|
if (lang >= chunkdata + slength) |
|
{ |
|
comp_flag = PNG_TEXT_COMPRESSION_NONE; |
|
png_warning(png_ptr, "Zero length iTXt chunk"); |
|
} |
|
else |
|
{ |
|
comp_flag = *lang++; |
|
comp_type = *lang++; |
|
} |
|
|
|
for (lang_key = lang; *lang_key; lang_key++) |
|
/* empty loop */ ; |
|
lang_key++; /* skip NUL separator */ |
|
|
|
for (text = lang_key; *text; text++) |
|
/* empty loop */ ; |
|
text++; /* skip NUL separator */ |
|
|
|
prefix_len = text - chunkdata; |
|
|
|
key=chunkdata; |
|
if (comp_flag) |
|
chunkdata = png_decompress_chunk(png_ptr, comp_type, chunkdata, |
|
(size_t)length, prefix_len, &data_len); |
|
else |
|
data_len=png_strlen(chunkdata + prefix_len); |
|
text_ptr = (png_textp)png_malloc(png_ptr, (png_uint_32)sizeof(png_text)); |
|
text_ptr->compression = (int)comp_flag + 1; |
|
text_ptr->lang_key = chunkdata+(lang_key-key); |
|
text_ptr->lang = chunkdata+(lang-key); |
|
text_ptr->itxt_length = data_len; |
|
text_ptr->text_length = 0; |
|
text_ptr->key = chunkdata; |
|
text_ptr->text = chunkdata + prefix_len; |
|
|
|
png_set_text(png_ptr, info_ptr, text_ptr, 1); |
|
|
|
png_free(png_ptr, text_ptr); |
|
png_free(png_ptr, chunkdata); |
|
} |
|
#endif |
|
|
|
/* This function is called when we haven't found a handler for a |
|
chunk. If there isn't a problem with the chunk itself (ie bad |
|
chunk name, CRC, or a critical chunk), the chunk is silently ignored |
|
-- unless the PNG_FLAG_UNKNOWN_CHUNKS_SUPPORTED flag is on in which |
|
case it will be saved away to be written out later. */ |
|
void /* PRIVATE */ |
|
png_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) |
|
{ |
|
png_uint_32 skip = 0; |
|
|
|
png_debug(1, "in png_handle_unknown\n"); |
|
|
|
if (png_ptr->mode & PNG_HAVE_IDAT) |
|
{ |
|
#ifdef PNG_USE_LOCAL_ARRAYS |
|
PNG_IDAT; |
|
#endif |
|
if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) /* not an IDAT */ |
|
png_ptr->mode |= PNG_AFTER_IDAT; |
|
} |
|
|
|
png_check_chunk_name(png_ptr, png_ptr->chunk_name); |
|
|
|
if (!(png_ptr->chunk_name[0] & 0x20)) |
|
{ |
|
#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED) |
|
if(png_handle_as_unknown(png_ptr, png_ptr->chunk_name) != |
|
HANDLE_CHUNK_ALWAYS |
|
#if defined(PNG_READ_USER_CHUNKS_SUPPORTED) |
|
&& png_ptr->read_user_chunk_fn == NULL |
|
#endif |
|
) |
|
#endif |
|
png_chunk_error(png_ptr, "unknown critical chunk"); |
|
} |
|
|
|
#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED) |
|
if (png_ptr->flags & PNG_FLAG_KEEP_UNKNOWN_CHUNKS) |
|
{ |
|
png_unknown_chunk chunk; |
|
|
|
#ifdef PNG_MAX_MALLOC_64K |
|
if (length > (png_uint_32)65535L) |
|
{ |
|
png_warning(png_ptr, "unknown chunk too large to fit in memory"); |
|
skip = length - (png_uint_32)65535L; |
|
length = (png_uint_32)65535L; |
|
} |
|
#endif |
|
png_strcpy((png_charp)chunk.name, (png_charp)png_ptr->chunk_name); |
|
chunk.data = (png_bytep)png_malloc(png_ptr, length); |
|
chunk.size = (png_size_t)length; |
|
png_crc_read(png_ptr, (png_bytep)chunk.data, length); |
|
#if defined(PNG_READ_USER_CHUNKS_SUPPORTED) |
|
if(png_ptr->read_user_chunk_fn != NULL) |
|
{ |
|
/* callback to user unknown chunk handler */ |
|
if ((*(png_ptr->read_user_chunk_fn)) (png_ptr, &chunk) <= 0) |
|
{ |
|
if (!(png_ptr->chunk_name[0] & 0x20)) |
|
if(png_handle_as_unknown(png_ptr, png_ptr->chunk_name) != |
|
HANDLE_CHUNK_ALWAYS) |
|
png_chunk_error(png_ptr, "unknown critical chunk"); |
|
png_set_unknown_chunks(png_ptr, info_ptr, &chunk, 1); |
|
} |
|
} |
|
else |
|
#endif |
|
png_set_unknown_chunks(png_ptr, info_ptr, &chunk, 1); |
|
png_free(png_ptr, chunk.data); |
|
} |
|
else |
|
#endif |
|
skip = length; |
|
|
|
png_crc_finish(png_ptr, skip); |
|
|
|
#if !defined(PNG_READ_USER_CHUNKS_SUPPORTED) |
|
info_ptr = 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. */ |
|
|
|
#define isnonalpha(c) ((c) < 41 || (c) > 122 || ((c) > 90 && (c) < 97)) |
|
|
|
void /* PRIVATE */ |
|
png_check_chunk_name(png_structp png_ptr, png_bytep chunk_name) |
|
{ |
|
png_debug(1, "in png_check_chunk_name\n"); |
|
if (isnonalpha(chunk_name[0]) || isnonalpha(chunk_name[1]) || |
|
isnonalpha(chunk_name[2]) || isnonalpha(chunk_name[3])) |
|
{ |
|
png_chunk_error(png_ptr, "invalid chunk type"); |
|
} |
|
} |
|
|
|
/* Combines the row recently read in with the existing pixels in the |
|
row. This routine takes care of alpha and transparency if requested. |
|
This routine also handles the two methods of progressive display |
|
of interlaced images, depending on the mask value. |
|
The mask value describes which pixels are to be combined with |
|
the row. The pattern always repeats every 8 pixels, so just 8 |
|
bits are needed. A one indicates the pixel is to be combined, |
|
a zero indicates the pixel is to be skipped. This is in addition |
|
to any alpha or transparency value associated with the pixel. If |
|
you want all pixels to be combined, pass 0xff (255) in mask. */ |
|
#ifndef PNG_HAVE_ASSEMBLER_COMBINE_ROW |
|
void /* PRIVATE */ |
|
png_combine_row(png_structp png_ptr, png_bytep row, int mask) |
|
{ |
|
png_debug(1,"in png_combine_row\n"); |
|
if (mask == 0xff) |
|
{ |
|
png_memcpy(row, png_ptr->row_buf + 1, |
|
(png_size_t)((png_ptr->width * |
|
png_ptr->row_info.pixel_depth + 7) >> 3)); |
|
} |
|
else |
|
{ |
|
switch (png_ptr->row_info.pixel_depth) |
|
{ |
|
case 1: |
|
{ |
|
png_bytep sp = png_ptr->row_buf + 1; |
|
png_bytep dp = row; |
|
int s_inc, s_start, s_end; |
|
int m = 0x80; |
|
int shift; |
|
png_uint_32 i; |
|
png_uint_32 row_width = png_ptr->width; |
|
|
|
#if defined(PNG_READ_PACKSWAP_SUPPORTED) |
|
if (png_ptr->transformations & PNG_PACKSWAP) |
|
{ |
|
s_start = 0; |
|
s_end = 7; |
|
s_inc = 1; |
|
} |
|
else |
|
#endif |
|
{ |
|
s_start = 7; |
|
s_end = 0; |
|
s_inc = -1; |
|
} |
|
|
|
shift = s_start; |
|
|
|
for (i = 0; i < row_width; i++) |
|
{ |
|
if (m & mask) |
|
{ |
|
int value; |
|
|
|
value = (*sp >> shift) & 0x01; |
|
*dp &= (png_byte)((0x7f7f >> (7 - shift)) & 0xff); |
|
*dp |= (png_byte)(value << shift); |
|
} |
|
|
|
if (shift == s_end) |
|
{ |
|
shift = s_start; |
|
sp++; |
|
dp++; |
|
} |
|
else |
|
shift += s_inc; |
|
|
|
if (m == 1) |
|
m = 0x80; |
|
else |
|
m >>= 1; |
|
} |
|
break; |
|
} |
|
case 2: |
|
{ |
|
png_bytep sp = png_ptr->row_buf + 1; |
|
png_bytep dp = row; |
|
int s_start, s_end, s_inc; |
|
int m = 0x80; |
|
int shift; |
|
png_uint_32 i; |
|
png_uint_32 row_width = png_ptr->width; |
|
int value; |
|
|
|
#if defined(PNG_READ_PACKSWAP_SUPPORTED) |
|
if (png_ptr->transformations & PNG_PACKSWAP) |
|
{ |
|
s_start = 0; |
|
s_end = 6; |
|
s_inc = 2; |
|
} |
|
else |
|
#endif |
|
{ |
|
s_start = 6; |
|
s_end = 0; |
|
s_inc = -2; |
|
} |
|
|
|
shift = s_start; |
|
|
|
for (i = 0; i < row_width; i++) |
|
{ |
|
if (m & mask) |
|
{ |
|
value = (*sp >> shift) & 0x03; |
|
*dp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff); |
|
*dp |= (png_byte)(value << shift); |
|
} |
|
|
|
if (shift == s_end) |
|
{ |
|
shift = s_start; |
|
sp++; |
|
dp++; |
|
} |
|
else |
|
shift += s_inc; |
|
if (m == 1) |
|
m = 0x80; |
|
else |
|
m >>= 1; |
|
} |
|
break; |
|
} |
|
case 4: |
|
{ |
|
png_bytep sp = png_ptr->row_buf + 1; |
|
png_bytep dp = row; |
|
int s_start, s_end, s_inc; |
|
int m = 0x80; |
|
int shift; |
|
png_uint_32 i; |
|
png_uint_32 row_width = png_ptr->width; |
|
int value; |
|
|
|
#if defined(PNG_READ_PACKSWAP_SUPPORTED) |
|
if (png_ptr->transformations & PNG_PACKSWAP) |
|
{ |
|
s_start = 0; |
|
s_end = 4; |
|
s_inc = 4; |
|
} |
|
else |
|
#endif |
|
{ |
|
s_start = 4; |
|
s_end = 0; |
|
s_inc = -4; |
|
} |
|
shift = s_start; |
|
|
|
for (i = 0; i < row_width; i++) |
|
{ |
|
if (m & mask) |
|
{ |
|
value = (*sp >> shift) & 0xf; |
|
*dp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff); |
|
*dp |= (png_byte)(value << shift); |
|
} |
|
|
|
if (shift == s_end) |
|
{ |
|
shift = s_start; |
|
sp++; |
|
dp++; |
|
} |
|
else |
|
shift += s_inc; |
|
if (m == 1) |
|
m = 0x80; |
|
else |
|
m >>= 1; |
|
} |
|
break; |
|
} |
|
default: |
|
{ |
|
png_bytep sp = png_ptr->row_buf + 1; |
|
png_bytep dp = row; |
|
png_size_t pixel_bytes = (png_ptr->row_info.pixel_depth >> 3); |
|
png_uint_32 i; |
|
png_uint_32 row_width = png_ptr->width; |
|
png_byte m = 0x80; |
|
|
|
|
|
for (i = 0; i < row_width; i++) |
|
{ |
|
if (m & mask) |
|
{ |
|
png_memcpy(dp, sp, pixel_bytes); |
|
} |
|
|
|
sp += pixel_bytes; |
|
dp += pixel_bytes; |
|
|
|
if (m == 1) |
|
m = 0x80; |
|
else |
|
m >>= 1; |
|
} |
|
break; |
|
} |
|
} |
|
} |
|
} |
|
#endif /* !PNG_HAVE_ASSEMBLER_COMBINE_ROW */ |
|
|
|
#ifdef PNG_READ_INTERLACING_SUPPORTED |
|
#ifndef PNG_HAVE_ASSEMBLER_READ_INTERLACE /* else in pngvcrd.c, pnggccrd.c */ |
|
/* OLD pre-1.0.9 interface: |
|
void png_do_read_interlace(png_row_infop row_info, png_bytep row, int pass, |
|
png_uint_32 transformations) |
|
*/ |
|
void /* PRIVATE */ |
|
png_do_read_interlace(png_structp png_ptr) |
|
{ |
|
png_row_infop row_info = &(png_ptr->row_info); |
|
png_bytep row = png_ptr->row_buf + 1; |
|
int pass = png_ptr->pass; |
|
png_uint_32 transformations = png_ptr->transformations; |
|
#ifdef PNG_USE_LOCAL_ARRAYS |
|
/* arrays to facilitate easy interlacing - use pass (0 - 6) as index */ |
|
/* offset to next interlace block */ |
|
const int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; |
|
#endif |
|
|
|
png_debug(1,"in png_do_read_interlace (stock C version)\n"); |
|
if (row != NULL && row_info != NULL) |
|
{ |
|
png_uint_32 final_width; |
|
|
|
final_width = row_info->width * png_pass_inc[pass]; |
|
|
|
switch (row_info->pixel_depth) |
|
{ |
|
case 1: |
|
{ |
|
png_bytep sp = row + (png_size_t)((row_info->width - 1) >> 3); |
|
png_bytep dp = row + (png_size_t)((final_width - 1) >> 3); |
|
int sshift, dshift; |
|
int s_start, s_end, s_inc; |
|
int jstop = png_pass_inc[pass]; |
|
png_byte v; |
|
png_uint_32 i; |
|
int j; |
|
|
|
#if defined(PNG_READ_PACKSWAP_SUPPORTED) |
|
if (transformations & PNG_PACKSWAP) |
|
{ |
|
sshift = (int)((row_info->width + 7) & 0x07); |
|
dshift = (int)((final_width + 7) & 0x07); |
|
s_start = 7; |
|
s_end = 0; |
|
s_inc = -1; |
|
} |
|
else |
|
#endif |
|
{ |
|
sshift = 7 - (int)((row_info->width + 7) & 0x07); |
|
dshift = 7 - (int)((final_width + 7) & 0x07); |
|
s_start = 0; |
|
s_end = 7; |
|
s_inc = 1; |
|
} |
|
|
|
for (i = 0; i < row_info->width; i++) |
|
{ |
|
v = (png_byte)((*sp >> sshift) & 0x01); |
|
for (j = 0; j < jstop; j++) |
|
{ |
|
*dp &= (png_byte)((0x7f7f >> (7 - dshift)) & 0xff); |
|
*dp |= (png_byte)(v << dshift); |
|
if (dshift == s_end) |
|
{ |
|
dshift = s_start; |
|
dp--; |
|
} |
|
else |
|
dshift += s_inc; |
|
} |
|
if (sshift == s_end) |
|
{ |
|
sshift = s_start; |
|
sp--; |
|
} |
|
else |
|
sshift += s_inc; |
|
} |
|
break; |
|
} |
|
case 2: |
|
{ |
|
png_bytep sp = row + (png_uint_32)((row_info->width - 1) >> 2); |
|
png_bytep dp = row + (png_uint_32)((final_width - 1) >> 2); |
|
int sshift, dshift; |
|
int s_start, s_end, s_inc; |
|
int jstop = png_pass_inc[pass]; |
|
png_uint_32 i; |
|
|
|
#if defined(PNG_READ_PACKSWAP_SUPPORTED) |
|
if (transformations & PNG_PACKSWAP) |
|
{ |
|
sshift = (int)(((row_info->width + 3) & 0x03) << 1); |
|
dshift = (int)(((final_width + 3) & 0x03) << 1); |
|
s_start = 6; |
|
s_end = 0; |
|
s_inc = -2; |
|
} |
|
else |
|
#endif |
|
{ |
|
sshift = (int)((3 - ((row_info->width + 3) & 0x03)) << 1); |
|
dshift = (int)((3 - ((final_width + 3) & 0x03)) << 1); |
|
s_start = 0; |
|
s_end = 6; |
|
s_inc = 2; |
|
} |
|
|
|
for (i = 0; i < row_info->width; i++) |
|
{ |
|
png_byte v; |
|
int j; |
|
|
|
v = (png_byte)((*sp >> sshift) & 0x03); |
|
for (j = 0; j < jstop; j++) |
|
{ |
|
*dp &= (png_byte)((0x3f3f >> (6 - dshift)) & 0xff); |
|
*dp |= (png_byte)(v << dshift); |
|
if (dshift == s_end) |
|
{ |
|
dshift = s_start; |
|
dp--; |
|
} |
|
else |
|
dshift += s_inc; |
|
} |
|
if (sshift == s_end) |
|
{ |
|
sshift = s_start; |
|
sp--; |
|
} |
|
else |
|
sshift += s_inc; |
|
} |
|
break; |
|
} |
|
case 4: |
|
{ |
|
png_bytep sp = row + (png_size_t)((row_info->width - 1) >> 1); |
|
png_bytep dp = row + (png_size_t)((final_width - 1) >> 1); |
|
int sshift, dshift; |
|
int s_start, s_end, s_inc; |
|
png_uint_32 i; |
|
int jstop = png_pass_inc[pass]; |
|
|
|
#if defined(PNG_READ_PACKSWAP_SUPPORTED) |
|
if (transformations & PNG_PACKSWAP) |
|
{ |
|
sshift = (int)(((row_info->width + 1) & 0x01) << 2); |
|
dshift = (int)(((final_width + 1) & 0x01) << 2); |
|
s_start = 4; |
|
s_end = 0; |
|
s_inc = -4; |
|
} |
|
else |
|
#endif |
|
{ |
|
sshift = (int)((1 - ((row_info->width + 1) & 0x01)) << 2); |
|
dshift = (int)((1 - ((final_width + 1) & 0x01)) << 2); |
|
s_start = 0; |
|
s_end = 4; |
|
s_inc = 4; |
|
} |
|
|
|
for (i = 0; i < row_info->width; i++) |
|
{ |
|
png_byte v = (png_byte)((*sp >> sshift) & 0xf); |
|
int j; |
|
|
|
for (j = 0; j < jstop; j++) |
|
{ |
|
*dp &= (png_byte)((0xf0f >> (4 - dshift)) & 0xff); |
|
*dp |= (png_byte)(v << dshift); |
|
if (dshift == s_end) |
|
{ |
|
dshift = s_start; |
|
dp--; |
|
} |
|
else |
|
dshift += s_inc; |
|
} |
|
if (sshift == s_end) |
|
{ |
|
sshift = s_start; |
|
sp--; |
|
} |
|
else |
|
sshift += s_inc; |
|
} |
|
break; |
|
} |
|
default: |
|
{ |
|
png_size_t pixel_bytes = (row_info->pixel_depth >> 3); |
|
png_bytep sp = row + (png_size_t)(row_info->width - 1) * pixel_bytes; |
|
png_bytep dp = row + (png_size_t)(final_width - 1) * pixel_bytes; |
|
|
|
int jstop = png_pass_inc[pass]; |
|
png_uint_32 i; |
|
|
|
for (i = 0; i < row_info->width; i++) |
|
{ |
|
png_byte v[8]; |
|
int j; |
|
|
|
png_memcpy(v, sp, pixel_bytes); |
|
for (j = 0; j < jstop; j++) |
|
{ |
|
png_memcpy(dp, v, pixel_bytes); |
|
dp -= pixel_bytes; |
|
} |
|
sp -= pixel_bytes; |
|
} |
|
break; |
|
} |
|
} |
|
row_info->width = final_width; |
|
row_info->rowbytes = ((final_width * |
|
(png_uint_32)row_info->pixel_depth + 7) >> 3); |
|
} |
|
#if !defined(PNG_READ_PACKSWAP_SUPPORTED) |
|
transformations = transformations; /* silence compiler warning */ |
|
#endif |
|
} |
|
#endif /* !PNG_HAVE_ASSEMBLER_READ_INTERLACE */ |
|
#endif /* PNG_READ_INTERLACING_SUPPORTED */ |
|
|
|
#ifndef PNG_HAVE_ASSEMBLER_READ_FILTER_ROW |
|
void /* PRIVATE */ |
|
png_read_filter_row(png_structp png_ptr, png_row_infop row_info, png_bytep row, |
|
png_bytep prev_row, int filter) |
|
{ |
|
png_debug(1, "in png_read_filter_row\n"); |
|
png_debug2(2,"row = %lu, filter = %d\n", png_ptr->row_number, filter); |
|
switch (filter) |
|
{ |
|
case PNG_FILTER_VALUE_NONE: |
|
break; |
|
case PNG_FILTER_VALUE_SUB: |
|
{ |
|
png_uint_32 i; |
|
png_uint_32 istop = row_info->rowbytes; |
|
png_uint_32 bpp = (row_info->pixel_depth + 7) >> 3; |
|
png_bytep rp = row + bpp; |
|
png_bytep lp = row; |
|
|
|
for (i = bpp; i < istop; i++) |
|
{ |
|
*rp = (png_byte)(((int)(*rp) + (int)(*lp++)) & 0xff); |
|
rp++; |
|
} |
|
break; |
|
} |
|
case PNG_FILTER_VALUE_UP: |
|
{ |
|
png_uint_32 i; |
|
png_uint_32 istop = row_info->rowbytes; |
|
png_bytep rp = row; |
|
png_bytep pp = prev_row; |
|
|
|
for (i = 0; i < istop; i++) |
|
{ |
|
*rp = (png_byte)(((int)(*rp) + (int)(*pp++)) & 0xff); |
|
rp++; |
|
} |
|
break; |
|
} |
|
case PNG_FILTER_VALUE_AVG: |
|
{ |
|
png_uint_32 i; |
|
png_bytep rp = row; |
|
png_bytep pp = prev_row; |
|
png_bytep lp = row; |
|
png_uint_32 bpp = (row_info->pixel_depth + 7) >> 3; |
|
png_uint_32 istop = row_info->rowbytes - bpp; |
|
|
|
for (i = 0; i < bpp; i++) |
|
{ |
|
*rp = (png_byte)(((int)(*rp) + |
|
((int)(*pp++) / 2 )) & 0xff); |
|
rp++; |
|
} |
|
|
|
for (i = 0; i < istop; i++) |
|
{ |
|
*rp = (png_byte)(((int)(*rp) + |
|
(int)(*pp++ + *lp++) / 2 ) & 0xff); |
|
rp++; |
|
} |
|
break; |
|
} |
|
case PNG_FILTER_VALUE_PAETH: |
|
{ |
|
png_uint_32 i; |
|
png_bytep rp = row; |
|
png_bytep pp = prev_row; |
|
png_bytep lp = row; |
|
png_bytep cp = prev_row; |
|
png_uint_32 bpp = (row_info->pixel_depth + 7) >> 3; |
|
png_uint_32 istop=row_info->rowbytes - bpp; |
|
|
|
for (i = 0; i < bpp; i++) |
|
{ |
|
*rp = (png_byte)(((int)(*rp) + (int)(*pp++)) & 0xff); |
|
rp++; |
|
} |
|
|
|
for (i = 0; i < istop; i++) /* use leftover rp,pp */ |
|
{ |
|
int a, b, c, pa, pb, pc, p; |
|
|
|
a = *lp++; |
|
b = *pp++; |
|
c = *cp++; |
|
|
|
p = b - c; |
|
pc = a - c; |
|
|
|
#ifdef PNG_USE_ABS |
|
pa = abs(p); |
|
pb = abs(pc); |
|
pc = abs(p + pc); |
|
#else |
|
pa = p < 0 ? -p : p; |
|
pb = pc < 0 ? -pc : pc; |
|
pc = (p + pc) < 0 ? -(p + pc) : p + pc; |
|
#endif |
|
|
|
/* |
|
if (pa <= pb && pa <= pc) |
|
p = a; |
|
else if (pb <= pc) |
|
p = b; |
|
else |
|
p = c; |
|
*/ |
|
|
|
p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c; |
|
|
|
*rp = (png_byte)(((int)(*rp) + p) & 0xff); |
|
rp++; |
|
} |
|
break; |
|
} |
|
default: |
|
png_warning(png_ptr, "Ignoring bad adaptive filter type"); |
|
*row=0; |
|
break; |
|
} |
|
} |
|
#endif /* !PNG_HAVE_ASSEMBLER_READ_FILTER_ROW */ |
|
|
|
void /* PRIVATE */ |
|
png_read_finish_row(png_structp png_ptr) |
|
{ |
|
#ifdef PNG_USE_LOCAL_ARRAYS |
|
/* arrays to facilitate easy interlacing - use pass (0 - 6) as index */ |
|
|
|
/* start of interlace block */ |
|
const int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; |
|
|
|
/* offset to next interlace block */ |
|
const int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; |
|
|
|
/* start of interlace block in the y direction */ |
|
const int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1}; |
|
|
|
/* offset to next interlace block in the y direction */ |
|
const int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; |
|
#endif |
|
|
|
png_debug(1, "in png_read_finish_row\n"); |
|
png_ptr->row_number++; |
|
if (png_ptr->row_number < png_ptr->num_rows) |
|
return; |
|
|
|
if (png_ptr->interlaced) |
|
{ |
|
png_ptr->row_number = 0; |
|
png_memset_check(png_ptr, png_ptr->prev_row, 0, png_ptr->rowbytes + 1); |
|
do |
|
{ |
|
png_ptr->pass++; |
|
if (png_ptr->pass >= 7) |
|
break; |
|
png_ptr->iwidth = (png_ptr->width + |
|
png_pass_inc[png_ptr->pass] - 1 - |
|
png_pass_start[png_ptr->pass]) / |
|
png_pass_inc[png_ptr->pass]; |
|
png_ptr->irowbytes = ((png_ptr->iwidth * |
|
(png_uint_32)png_ptr->pixel_depth + 7) >> 3) +1; |
|
|
|
if (!(png_ptr->transformations & PNG_INTERLACE)) |
|
{ |
|
png_ptr->num_rows = (png_ptr->height + |
|
png_pass_yinc[png_ptr->pass] - 1 - |
|
png_pass_ystart[png_ptr->pass]) / |
|
png_pass_yinc[png_ptr->pass]; |
|
if (!(png_ptr->num_rows)) |
|
continue; |
|
} |
|
else /* if (png_ptr->transformations & PNG_INTERLACE) */ |
|
break; |
|
} while (png_ptr->iwidth == 0); |
|
|
|
if (png_ptr->pass < 7) |
|
return; |
|
} |
|
|
|
if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED)) |
|
{ |
|
#ifdef PNG_USE_LOCAL_ARRAYS |
|
PNG_IDAT; |
|
#endif |
|
char extra; |
|
int ret; |
|
|
|
png_ptr->zstream.next_out = (Byte *)&extra; |
|
png_ptr->zstream.avail_out = (uInt)1; |
|
for(;;) |
|
{ |
|
if (!(png_ptr->zstream.avail_in)) |
|
{ |
|
while (!png_ptr->idat_size) |
|
{ |
|
png_byte chunk_length[4]; |
|
|
|
png_crc_finish(png_ptr, 0); |
|
|
|
png_read_data(png_ptr, chunk_length, 4); |
|
png_ptr->idat_size = png_get_uint_32(chunk_length); |
|
|
|
png_reset_crc(png_ptr); |
|
png_crc_read(png_ptr, png_ptr->chunk_name, 4); |
|
if (png_memcmp(png_ptr->chunk_name, (png_bytep)png_IDAT, 4)) |
|
png_error(png_ptr, "Not enough image data"); |
|
|
|
} |
|
png_ptr->zstream.avail_in = (uInt)png_ptr->zbuf_size; |
|
png_ptr->zstream.next_in = png_ptr->zbuf; |
|
if (png_ptr->zbuf_size > png_ptr->idat_size) |
|
png_ptr->zstream.avail_in = (uInt)png_ptr->idat_size; |
|
png_crc_read(png_ptr, png_ptr->zbuf, png_ptr->zstream.avail_in); |
|
png_ptr->idat_size -= png_ptr->zstream.avail_in; |
|
} |
|
ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH); |
|
if (ret == Z_STREAM_END) |
|
{ |
|
if (!(png_ptr->zstream.avail_out) || png_ptr->zstream.avail_in || |
|
png_ptr->idat_size) |
|
png_error(png_ptr, "Extra compressed data"); |
|
png_ptr->mode |= PNG_AFTER_IDAT; |
|
png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED; |
|
break; |
|
} |
|
if (ret != Z_OK) |
|
png_error(png_ptr, png_ptr->zstream.msg ? png_ptr->zstream.msg : |
|
"Decompression Error"); |
|
|
|
if (!(png_ptr->zstream.avail_out)) |
|
png_error(png_ptr, "Extra compressed data"); |
|
|
|
} |
|
png_ptr->zstream.avail_out = 0; |
|
} |
|
|
|
if (png_ptr->idat_size || png_ptr->zstream.avail_in) |
|
png_error(png_ptr, "Extra compression data"); |
|
|
|
inflateReset(&png_ptr->zstream); |
|
|
|
png_ptr->mode |= PNG_AFTER_IDAT; |
|
} |
|
|
|
void /* PRIVATE */ |
|
png_read_start_row(png_structp png_ptr) |
|
{ |
|
#ifdef PNG_USE_LOCAL_ARRAYS |
|
/* arrays to facilitate easy interlacing - use pass (0 - 6) as index */ |
|
|
|
/* start of interlace block */ |
|
const int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; |
|
|
|
/* offset to next interlace block */ |
|
const int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; |
|
|
|
/* start of interlace block in the y direction */ |
|
const int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1}; |
|
|
|
/* offset to next interlace block in the y direction */ |
|
const int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; |
|
#endif |
|
|
|
int max_pixel_depth; |
|
png_uint_32 row_bytes; |
|
|
|
png_debug(1, "in png_read_start_row\n"); |
|
png_ptr->zstream.avail_in = 0; |
|
png_init_read_transformations(png_ptr); |
|
if (png_ptr->interlaced) |
|
{ |
|
if (!(png_ptr->transformations & PNG_INTERLACE)) |
|
png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 - |
|
png_pass_ystart[0]) / png_pass_yinc[0]; |
|
else |
|
png_ptr->num_rows = png_ptr->height; |
|
|
|
png_ptr->iwidth = (png_ptr->width + |
|
png_pass_inc[png_ptr->pass] - 1 - |
|
png_pass_start[png_ptr->pass]) / |
|
png_pass_inc[png_ptr->pass]; |
|
|
|
row_bytes = ((png_ptr->iwidth * |
|
(png_uint_32)png_ptr->pixel_depth + 7) >> 3) +1; |
|
png_ptr->irowbytes = (png_size_t)row_bytes; |
|
if((png_uint_32)png_ptr->irowbytes != row_bytes) |
|
png_error(png_ptr, "Rowbytes overflow in png_read_start_row"); |
|
} |
|
else |
|
{ |
|
png_ptr->num_rows = png_ptr->height; |
|
png_ptr->iwidth = png_ptr->width; |
|
png_ptr->irowbytes = png_ptr->rowbytes + 1; |
|
} |
|
max_pixel_depth = png_ptr->pixel_depth; |
|
|
|
#if defined(PNG_READ_PACK_SUPPORTED) |
|
if ((png_ptr->transformations & PNG_PACK) && png_ptr->bit_depth < 8) |
|
max_pixel_depth = 8; |
|
#endif |
|
|
|
#if defined(PNG_READ_EXPAND_SUPPORTED) |
|
if (png_ptr->transformations & PNG_EXPAND) |
|
{ |
|
if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) |
|
{ |
|
if (png_ptr->num_trans) |
|
max_pixel_depth = 32; |
|
else |
|
max_pixel_depth = 24; |
|
} |
|
else if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY) |
|
{ |
|
if (max_pixel_depth < 8) |
|
max_pixel_depth = 8; |
|
if (png_ptr->num_trans) |
|
max_pixel_depth *= 2; |
|
} |
|
else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB) |
|
{ |
|
if (png_ptr->num_trans) |
|
{ |
|
max_pixel_depth *= 4; |
|
max_pixel_depth /= 3; |
|
} |
|
} |
|
} |
|
#endif |
|
|
|
#if defined(PNG_READ_FILLER_SUPPORTED) |
|
if (png_ptr->transformations & (PNG_FILLER)) |
|
{ |
|
if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) |
|
max_pixel_depth = 32; |
|
else if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY) |
|
{ |
|
if (max_pixel_depth <= 8) |
|
max_pixel_depth = 16; |
|
else |
|
max_pixel_depth = 32; |
|
} |
|
else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB) |
|
{ |
|
if (max_pixel_depth <= 32) |
|
max_pixel_depth = 32; |
|
else |
|
max_pixel_depth = 64; |
|
} |
|
} |
|
#endif |
|
|
|
#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED) |
|
if (png_ptr->transformations & PNG_GRAY_TO_RGB) |
|
{ |
|
if ( |
|
#if defined(PNG_READ_EXPAND_SUPPORTED) |
|
(png_ptr->num_trans && (png_ptr->transformations & PNG_EXPAND)) || |
|
#endif |
|
#if defined(PNG_READ_FILLER_SUPPORTED) |
|
(png_ptr->transformations & (PNG_FILLER)) || |
|
#endif |
|
png_ptr->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) |
|
{ |
|
if (max_pixel_depth <= 16) |
|
max_pixel_depth = 32; |
|
else |
|
max_pixel_depth = 64; |
|
} |
|
else |
|
{ |
|
if (max_pixel_depth <= 8) |
|
{ |
|
if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA) |
|
max_pixel_depth = 32; |
|
else |
|
max_pixel_depth = 24; |
|
} |
|
else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA) |
|
max_pixel_depth = 64; |
|
else |
|
max_pixel_depth = 48; |
|
} |
|
} |
|
#endif |
|
|
|
#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) && \ |
|
defined(PNG_USER_TRANSFORM_PTR_SUPPORTED) |
|
if(png_ptr->transformations & PNG_USER_TRANSFORM) |
|
{ |
|
int user_pixel_depth=png_ptr->user_transform_depth* |
|
png_ptr->user_transform_channels; |
|
if(user_pixel_depth > max_pixel_depth) |
|
max_pixel_depth=user_pixel_depth; |
|
} |
|
#endif |
|
|
|
/* align the width on the next larger 8 pixels. Mainly used |
|
for interlacing */ |
|
row_bytes = ((png_ptr->width + 7) & ~((png_uint_32)7)); |
|
/* calculate the maximum bytes needed, adding a byte and a pixel |
|
for safety's sake */ |
|
row_bytes = ((row_bytes * (png_uint_32)max_pixel_depth + 7) >> 3) + |
|
1 + ((max_pixel_depth + 7) >> 3); |
|
#ifdef PNG_MAX_MALLOC_64K |
|
if (row_bytes > (png_uint_32)65536L) |
|
png_error(png_ptr, "This image requires a row greater than 64KB"); |
|
#endif |
|
png_ptr->big_row_buf = (png_bytep)png_malloc(png_ptr, row_bytes+64); |
|
png_ptr->row_buf = png_ptr->big_row_buf+32; |
|
#if defined(PNG_DEBUG) && defined(PNG_USE_PNGGCCRD) |
|
png_ptr->row_buf_size = row_bytes; |
|
#endif |
|
|
|
#ifdef PNG_MAX_MALLOC_64K |
|
if ((png_uint_32)png_ptr->rowbytes + 1 > (png_uint_32)65536L) |
|
png_error(png_ptr, "This image requires a row greater than 64KB"); |
|
#endif |
|
png_ptr->prev_row = (png_bytep)png_malloc(png_ptr, (png_uint_32)( |
|
png_ptr->rowbytes + 1)); |
|
|
|
png_memset_check(png_ptr, png_ptr->prev_row, 0, png_ptr->rowbytes + 1); |
|
|
|
png_debug1(3, "width = %lu,\n", png_ptr->width); |
|
png_debug1(3, "height = %lu,\n", png_ptr->height); |
|
png_debug1(3, "iwidth = %lu,\n", png_ptr->iwidth); |
|
png_debug1(3, "num_rows = %lu\n", png_ptr->num_rows); |
|
png_debug1(3, "rowbytes = %lu,\n", png_ptr->rowbytes); |
|
png_debug1(3, "irowbytes = %lu,\n", png_ptr->irowbytes); |
|
|
|
png_ptr->flags |= PNG_FLAG_ROW_INIT; |
|
}
|
|
|