mirror of
https://github.com/AquariaOSE/Aquaria.git
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2372 lines
66 KiB
C
2372 lines
66 KiB
C
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/* pngrutil.c - utilities to read a PNG file
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*
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* libpng 1.0.2 - June 14, 1998
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* For conditions of distribution and use, see copyright notice in png.h
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* Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
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* Copyright (c) 1996, 1997 Andreas Dilger
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* Copyright (c) 1998, Glenn Randers-Pehrson
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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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#define PNG_INTERNAL
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#include "png.h"
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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
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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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return (i);
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}
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#if defined(PNG_READ_pCAL_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
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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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return (i);
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}
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#endif /* PNG_READ_pCAL_SUPPORTED */
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/* Grab an unsigned 16-bit integer from a buffer in big-endian format. */
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png_uint_16
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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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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
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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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/* 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
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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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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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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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return (0);
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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
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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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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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/* read and check the IDHR chunk */
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void
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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_BEFORE_IHDR)
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png_error(png_ptr, "Out of place IHDR");
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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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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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/* check for width and height valid values */
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if (width == 0 || width > (png_uint_32)2147483647L || height == 0 ||
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height > (png_uint_32)2147483647L)
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png_error(png_ptr, "Invalid image size in IHDR");
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/* check other values */
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if (bit_depth != 1 && bit_depth != 2 && bit_depth != 4 &&
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bit_depth != 8 && bit_depth != 16)
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png_error(png_ptr, "Invalid bit depth in IHDR");
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if (color_type < 0 || color_type == 1 ||
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color_type == 5 || color_type > 6)
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png_error(png_ptr, "Invalid color type in IHDR");
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if ((color_type == PNG_COLOR_TYPE_PALETTE && bit_depth) > 8 ||
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((color_type == PNG_COLOR_TYPE_RGB ||
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color_type == PNG_COLOR_TYPE_GRAY_ALPHA ||
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color_type == PNG_COLOR_TYPE_RGB_ALPHA) && bit_depth < 8))
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png_error(png_ptr, "Invalid color type/bit depth combination in IHDR");
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if (interlace_type >= PNG_INTERLACE_LAST)
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png_error(png_ptr, "Unknown interlace method in IHDR");
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if (compression_type != PNG_COMPRESSION_TYPE_BASE)
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png_error(png_ptr, "Unknown compression method in IHDR");
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if (filter_type != PNG_FILTER_TYPE_BASE)
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png_error(png_ptr, "Unknown filter method in IHDR");
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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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/* 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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/* 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 = %d\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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/* read and check the palette */
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void
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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_colorp palette;
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int num, i;
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png_debug(1, "in png_handle_PLTE\n");
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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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png_ptr->mode |= PNG_HAVE_PLTE;
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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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if (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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palette = (png_colorp)png_zalloc(png_ptr, (uInt)num, sizeof (png_color));
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png_ptr->flags |= PNG_FLAG_FREE_PALETTE;
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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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/* If we actually NEED the PLTE chunk (ie for a paletted image), we do
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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
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we will act as though it is. */
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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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#endif
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{
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png_crc_finish(png_ptr, 0);
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}
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#if !defined(PNG_READ_OPT_PLTE_SUPPORTED)
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else if (png_crc_error(png_ptr)) /* Only if we have a CRC error */
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{
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/* If we don't want to use the data from an ancillary chunk,
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we have two options: an error abort, or a warning and we
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ignore the data in this chunk (which should be OK, since
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it's considered ancillary for a RGB or RGBA image). */
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if (!(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_USE))
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{
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if (png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN)
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{
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png_chunk_error(png_ptr, "CRC error");
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}
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else
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{
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png_chunk_warning(png_ptr, "CRC error");
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png_ptr->flags &= ~PNG_FLAG_FREE_PALETTE;
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png_zfree(png_ptr, palette);
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return;
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}
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}
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/* Otherwise, we (optionally) emit a warning and use the chunk. */
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else if (!(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN))
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{
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png_chunk_warning(png_ptr, "CRC error");
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}
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}
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#endif
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png_ptr->palette = palette;
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png_ptr->num_palette = (png_uint_16)num;
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png_set_PLTE(png_ptr, info_ptr, palette, num);
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#if defined (PNG_READ_tRNS_SUPPORTED)
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if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
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{
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if (info_ptr != NULL && info_ptr->valid & PNG_INFO_tRNS)
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{
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if (png_ptr->num_trans > png_ptr->num_palette)
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{
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png_warning(png_ptr, "Truncating incorrect tRNS chunk length");
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png_ptr->num_trans = png_ptr->num_palette;
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}
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}
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}
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#endif
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}
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void
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png_handle_IEND(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
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{
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png_debug(1, "in png_handle_IEND\n");
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if (!(png_ptr->mode & PNG_HAVE_IHDR) || !(png_ptr->mode & PNG_HAVE_IDAT))
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{
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png_error(png_ptr, "No image in file");
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/* to quiet compiler warnings about unused info_ptr */
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if (info_ptr == NULL)
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return;
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}
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png_ptr->mode |= PNG_AFTER_IDAT | PNG_HAVE_IEND;
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if (length != 0)
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{
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png_warning(png_ptr, "Incorrect IEND chunk length");
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}
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png_crc_finish(png_ptr, length);
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}
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#if defined(PNG_READ_gAMA_SUPPORTED)
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void
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png_handle_gAMA(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
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{
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png_uint_32 igamma;
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float file_gamma;
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png_byte buf[4];
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png_debug(1, "in png_handle_gAMA\n");
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if (!(png_ptr->mode & PNG_HAVE_IHDR))
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png_error(png_ptr, "Missing IHDR before gAMA");
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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 gAMA 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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/* Should be an error, but we can cope with it */
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png_warning(png_ptr, "Out of place gAMA chunk");
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else if (info_ptr != NULL && info_ptr->valid & PNG_INFO_gAMA
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#if defined(PNG_READ_sRGB_SUPPORTED)
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&& !(info_ptr->valid & PNG_INFO_sRGB)
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#endif
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)
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{
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png_warning(png_ptr, "Duplicate gAMA chunk");
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png_crc_finish(png_ptr, length);
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return;
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}
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if (length != 4)
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{
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png_warning(png_ptr, "Incorrect gAMA chunk length");
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png_crc_finish(png_ptr, length);
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return;
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}
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png_crc_read(png_ptr, buf, 4);
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if (png_crc_finish(png_ptr, 0))
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return;
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igamma = png_get_uint_32(buf);
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/* check for zero gamma */
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if (igamma == 0)
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return;
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#if defined(PNG_READ_sRGB_SUPPORTED)
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if (info_ptr->valid & PNG_INFO_sRGB)
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if(igamma != (png_uint_32)45000L)
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{
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png_warning(png_ptr,
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"Ignoring incorrect gAMA value when sRGB is also present");
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#ifndef PNG_NO_STDIO
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fprintf(stderr, "igamma = %lu\n", igamma);
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#endif
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return;
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}
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#endif /* PNG_READ_sRGB_SUPPORTED */
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file_gamma = (float)igamma / (float)100000.0;
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#ifdef PNG_READ_GAMMA_SUPPORTED
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png_ptr->gamma = file_gamma;
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#endif
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png_set_gAMA(png_ptr, info_ptr, file_gamma);
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}
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#endif
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#if defined(PNG_READ_sBIT_SUPPORTED)
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void
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png_handle_sBIT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
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{
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png_size_t truelen;
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png_byte buf[4];
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png_debug(1, "in png_handle_sBIT\n");
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buf[0] = buf[1] = buf[2] = buf[3] = 0;
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if (!(png_ptr->mode & PNG_HAVE_IHDR))
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png_error(png_ptr, "Missing IHDR before sBIT");
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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 sBIT 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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{
|
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/* Should be an error, but we can cope with it */
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png_warning(png_ptr, "Out of place sBIT chunk");
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}
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else if (info_ptr != NULL && info_ptr->valid & PNG_INFO_sBIT)
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{
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png_warning(png_ptr, "Duplicate sBIT chunk");
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png_crc_finish(png_ptr, length);
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return;
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}
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if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
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truelen = 3;
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else
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truelen = (png_size_t)png_ptr->channels;
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if (length != truelen)
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{
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png_warning(png_ptr, "Incorrect sBIT chunk length");
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png_crc_finish(png_ptr, length);
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return;
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}
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png_crc_read(png_ptr, buf, truelen);
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if (png_crc_finish(png_ptr, 0))
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return;
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if (png_ptr->color_type & PNG_COLOR_MASK_COLOR)
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{
|
|
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.alpha = buf[1];
|
|
}
|
|
png_set_sBIT(png_ptr, info_ptr, &(png_ptr->sig_bit));
|
|
}
|
|
#endif
|
|
|
|
#if defined(PNG_READ_cHRM_SUPPORTED)
|
|
void
|
|
png_handle_cHRM(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
|
|
{
|
|
png_byte buf[4];
|
|
png_uint_32 val;
|
|
float white_x, white_y, red_x, red_y, green_x, green_y, blue_x, blue_y;
|
|
|
|
png_debug(1, "in png_handle_cHRM\n");
|
|
|
|
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 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);
|
|
val = png_get_uint_32(buf);
|
|
white_x = (float)val / (float)100000.0;
|
|
|
|
png_crc_read(png_ptr, buf, 4);
|
|
val = png_get_uint_32(buf);
|
|
white_y = (float)val / (float)100000.0;
|
|
|
|
if (white_x < 0 || white_x > 0.8 || white_y < 0 || white_y > 0.8 ||
|
|
white_x + white_y > 1.0)
|
|
{
|
|
png_warning(png_ptr, "Invalid cHRM white point");
|
|
png_crc_finish(png_ptr, 24);
|
|
return;
|
|
}
|
|
|
|
png_crc_read(png_ptr, buf, 4);
|
|
val = png_get_uint_32(buf);
|
|
red_x = (float)val / (float)100000.0;
|
|
|
|
png_crc_read(png_ptr, buf, 4);
|
|
val = png_get_uint_32(buf);
|
|
red_y = (float)val / (float)100000.0;
|
|
|
|
if (red_x < 0 || red_x > 0.8 || red_y < 0 || red_y > 0.8 ||
|
|
red_x + red_y > 1.0)
|
|
{
|
|
png_warning(png_ptr, "Invalid cHRM red point");
|
|
png_crc_finish(png_ptr, 16);
|
|
return;
|
|
}
|
|
|
|
png_crc_read(png_ptr, buf, 4);
|
|
val = png_get_uint_32(buf);
|
|
green_x = (float)val / (float)100000.0;
|
|
|
|
png_crc_read(png_ptr, buf, 4);
|
|
val = png_get_uint_32(buf);
|
|
green_y = (float)val / (float)100000.0;
|
|
|
|
if (green_x < 0 || green_x > 0.8 || green_y < 0 || green_y > 0.8 ||
|
|
green_x + green_y > 1.0)
|
|
{
|
|
png_warning(png_ptr, "Invalid cHRM green point");
|
|
png_crc_finish(png_ptr, 8);
|
|
return;
|
|
}
|
|
|
|
png_crc_read(png_ptr, buf, 4);
|
|
val = png_get_uint_32(buf);
|
|
blue_x = (float)val / (float)100000.0;
|
|
|
|
png_crc_read(png_ptr, buf, 4);
|
|
val = png_get_uint_32(buf);
|
|
blue_y = (float)val / (float)100000.0;
|
|
|
|
if (blue_x < (float)0 || blue_x > (float)0.8 || blue_y < (float)0 ||
|
|
blue_y > (float)0.8 || blue_x + blue_y > (float)1.0)
|
|
{
|
|
png_warning(png_ptr, "Invalid cHRM blue point");
|
|
png_crc_finish(png_ptr, 0);
|
|
return;
|
|
}
|
|
|
|
if (png_crc_finish(png_ptr, 0))
|
|
return;
|
|
|
|
#if defined(PNG_READ_sRGB_SUPPORTED)
|
|
if (info_ptr->valid & PNG_INFO_sRGB)
|
|
{
|
|
if (fabs(white_x - (float).3127) > (float).001 ||
|
|
fabs(white_y - (float).3290) > (float).001 ||
|
|
fabs( red_x - (float).6400) > (float).001 ||
|
|
fabs( red_y - (float).3300) > (float).001 ||
|
|
fabs(green_x - (float).3000) > (float).001 ||
|
|
fabs(green_y - (float).6000) > (float).001 ||
|
|
fabs( blue_x - (float).1500) > (float).001 ||
|
|
fabs( blue_y - (float).0600) > (float).001)
|
|
{
|
|
|
|
png_warning(png_ptr,
|
|
"Ignoring incorrect cHRM value when sRGB is also present");
|
|
#ifndef PNG_NO_STDIO
|
|
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);
|
|
#endif
|
|
}
|
|
return;
|
|
}
|
|
#endif /* PNG_READ_sRGB_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
|
|
|
|
#if defined(PNG_READ_sRGB_SUPPORTED)
|
|
void
|
|
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))
|
|
if((png_uint_32)(png_ptr->gamma*(float)100000.+.5) != (png_uint_32)45000L)
|
|
{
|
|
png_warning(png_ptr,
|
|
"Ignoring incorrect gAMA value when sRGB is also present");
|
|
#ifndef PNG_NO_STDIO
|
|
fprintf(stderr,"gamma=%f\n",png_ptr->gamma);
|
|
#endif
|
|
}
|
|
#endif /* PNG_READ_gAMA_SUPPORTED */
|
|
|
|
#ifdef PNG_READ_cHRM_SUPPORTED
|
|
if (info_ptr->valid & PNG_INFO_cHRM)
|
|
if (fabs(info_ptr->x_white - (float).3127) > (float).001 ||
|
|
fabs(info_ptr->y_white - (float).3290) > (float).001 ||
|
|
fabs( info_ptr->x_red - (float).6400) > (float).001 ||
|
|
fabs( info_ptr->y_red - (float).3300) > (float).001 ||
|
|
fabs(info_ptr->x_green - (float).3000) > (float).001 ||
|
|
fabs(info_ptr->y_green - (float).6000) > (float).001 ||
|
|
fabs( info_ptr->x_blue - (float).1500) > (float).001 ||
|
|
fabs( info_ptr->y_blue - (float).0600) > (float).001)
|
|
{
|
|
png_warning(png_ptr,
|
|
"Ignoring incorrect cHRM value when sRGB is also present");
|
|
}
|
|
#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_tRNS_SUPPORTED)
|
|
void
|
|
png_handle_tRNS(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
|
|
{
|
|
png_debug(1, "in png_handle_tRNS\n");
|
|
|
|
if (!(png_ptr->mode & PNG_HAVE_IHDR))
|
|
png_error(png_ptr, "Missing IHDR before tRNS");
|
|
else if (png_ptr->mode & PNG_HAVE_IDAT)
|
|
{
|
|
png_warning(png_ptr, "Invalid tRNS after IDAT");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
else if (info_ptr != NULL && info_ptr->valid & PNG_INFO_tRNS)
|
|
{
|
|
png_warning(png_ptr, "Duplicate tRNS chunk");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
|
|
if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
|
|
{
|
|
if (!(png_ptr->mode & PNG_HAVE_PLTE))
|
|
{
|
|
/* Should be an error, but we can cope with it */
|
|
png_warning(png_ptr, "Missing PLTE before tRNS");
|
|
}
|
|
else if (length > png_ptr->num_palette)
|
|
{
|
|
png_warning(png_ptr, "Incorrect tRNS chunk length");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
if (length == 0)
|
|
{
|
|
png_warning(png_ptr, "Zero length tRNS chunk");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
|
|
png_ptr->trans = (png_bytep)png_malloc(png_ptr, length);
|
|
png_ptr->flags |= PNG_FLAG_FREE_TRANS;
|
|
png_crc_read(png_ptr, png_ptr->trans, (png_size_t)length);
|
|
png_ptr->num_trans = (png_uint_16)length;
|
|
}
|
|
else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB)
|
|
{
|
|
png_byte buf[6];
|
|
|
|
if (length != 6)
|
|
{
|
|
png_warning(png_ptr, "Incorrect tRNS chunk length");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
|
|
png_crc_read(png_ptr, buf, (png_size_t)length);
|
|
png_ptr->num_trans = 1;
|
|
png_ptr->trans_values.red = png_get_uint_16(buf);
|
|
png_ptr->trans_values.green = png_get_uint_16(buf + 2);
|
|
png_ptr->trans_values.blue = png_get_uint_16(buf + 4);
|
|
}
|
|
else if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY)
|
|
{
|
|
png_byte buf[6];
|
|
|
|
if (length != 2)
|
|
{
|
|
png_warning(png_ptr, "Incorrect tRNS chunk length");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
|
|
png_crc_read(png_ptr, buf, 2);
|
|
png_ptr->num_trans = 1;
|
|
png_ptr->trans_values.gray = png_get_uint_16(buf);
|
|
}
|
|
else
|
|
{
|
|
png_warning(png_ptr, "tRNS chunk not allowed with alpha channel");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
|
|
if (png_crc_finish(png_ptr, 0))
|
|
return;
|
|
|
|
png_set_tRNS(png_ptr, info_ptr, png_ptr->trans, png_ptr->num_trans,
|
|
&(png_ptr->trans_values));
|
|
}
|
|
#endif
|
|
|
|
#if defined(PNG_READ_bKGD_SUPPORTED)
|
|
void
|
|
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];
|
|
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
|
|
png_handle_hIST(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
|
|
{
|
|
int num, i;
|
|
|
|
png_debug(1, "in png_handle_hIST\n");
|
|
|
|
if (!(png_ptr->mode & PNG_HAVE_IHDR))
|
|
png_error(png_ptr, "Missing IHDR before hIST");
|
|
else if (png_ptr->mode & PNG_HAVE_IDAT)
|
|
{
|
|
png_warning(png_ptr, "Invalid hIST after IDAT");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
else if (!(png_ptr->mode & PNG_HAVE_PLTE))
|
|
{
|
|
png_warning(png_ptr, "Missing PLTE before hIST");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
else if (info_ptr != NULL && info_ptr->valid & PNG_INFO_hIST)
|
|
{
|
|
png_warning(png_ptr, "Duplicate hIST chunk");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
|
|
if (length != (png_uint_32)(2 * png_ptr->num_palette))
|
|
{
|
|
png_warning(png_ptr, "Incorrect hIST chunk length");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
|
|
num = (int)length / 2;
|
|
png_ptr->hist = (png_uint_16p)png_malloc(png_ptr,
|
|
(png_uint_32)(num * sizeof (png_uint_16)));
|
|
png_ptr->flags |= PNG_FLAG_FREE_HIST;
|
|
for (i = 0; i < num; i++)
|
|
{
|
|
png_byte buf[2];
|
|
|
|
png_crc_read(png_ptr, buf, 2);
|
|
png_ptr->hist[i] = png_get_uint_16(buf);
|
|
}
|
|
|
|
if (png_crc_finish(png_ptr, 0))
|
|
return;
|
|
|
|
png_set_hIST(png_ptr, info_ptr, png_ptr->hist);
|
|
}
|
|
#endif
|
|
|
|
#if defined(PNG_READ_pHYs_SUPPORTED)
|
|
void
|
|
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
|
|
png_handle_oFFs(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
|
|
{
|
|
png_byte buf[9];
|
|
png_uint_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_uint_32(buf);
|
|
offset_y = png_get_uint_32(buf + 4);
|
|
unit_type = buf[8];
|
|
png_set_oFFs(png_ptr, info_ptr, offset_x, offset_y, unit_type);
|
|
}
|
|
#endif
|
|
|
|
#if defined(PNG_READ_pCAL_SUPPORTED)
|
|
/* read the pCAL chunk (png-scivis-19970203) */
|
|
void
|
|
png_handle_pCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
|
|
{
|
|
png_charp purpose;
|
|
png_int_32 X0, X1;
|
|
png_byte type, nparams;
|
|
png_charp buf, units, endptr;
|
|
png_charpp params;
|
|
png_size_t slength;
|
|
int i;
|
|
|
|
png_debug(1, "in png_handle_pCAL\n");
|
|
|
|
if (!(png_ptr->mode & PNG_HAVE_IHDR))
|
|
png_error(png_ptr, "Missing IHDR before pCAL");
|
|
else if (png_ptr->mode & PNG_HAVE_IDAT)
|
|
{
|
|
png_warning(png_ptr, "Invalid pCAL after IDAT");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
else if (info_ptr != NULL && info_ptr->valid & PNG_INFO_pCAL)
|
|
{
|
|
png_warning(png_ptr, "Duplicate pCAL chunk");
|
|
png_crc_finish(png_ptr, length);
|
|
return;
|
|
}
|
|
|
|
png_debug1(2, "Allocating and reading pCAL chunk data (%d bytes)\n",
|
|
length + 1);
|
|
purpose = (png_charp)png_malloc(png_ptr, length + 1);
|
|
slength = (png_size_t)length;
|
|
png_crc_read(png_ptr, (png_bytep)purpose, slength);
|
|
|
|
if (png_crc_finish(png_ptr, 0))
|
|
{
|
|
png_free(png_ptr, purpose);
|
|
return;
|
|
}
|
|
|
|
purpose[slength] = 0x00; /* null terminate the last string */
|
|
|
|
png_debug(3, "Finding end of pCAL purpose string\n");
|
|
for (buf = purpose; *buf; buf++)
|
|
/* empty loop */ ;
|
|
|
|
endptr = purpose + slength;
|
|
|
|
/* We need to have at least 12 bytes after the purpose string
|
|
in order to get the parameter information. */
|
|
if (endptr <= buf + 12)
|
|
{
|
|
png_warning(png_ptr, "Invalid pCAL data");
|
|
png_free(png_ptr, purpose);
|
|
return;
|
|
}
|
|
|
|
png_debug(3, "Reading pCAL X0, X1, type, nparams, and units\n");
|
|
X0 = png_get_int_32((png_bytep)buf+1);
|
|
X1 = png_get_int_32((png_bytep)buf+5);
|
|
type = buf[9];
|
|
nparams = buf[10];
|
|
units = buf + 11;
|
|
|
|
png_debug(3, "Checking pCAL equation type and number of parameters\n");
|
|
/* Check that we have the right number of parameters for known
|
|
equation types. */
|
|
if ((type == PNG_EQUATION_LINEAR && nparams != 2) ||
|
|
(type == PNG_EQUATION_BASE_E && nparams != 3) ||
|
|
(type == PNG_EQUATION_ARBITRARY && nparams != 3) ||
|
|
(type == PNG_EQUATION_HYPERBOLIC && nparams != 4))
|
|
{
|
|
png_warning(png_ptr, "Invalid pCAL parameters for equation type");
|
|
png_free(png_ptr, purpose);
|
|
return;
|
|
}
|
|
else if (type >= PNG_EQUATION_LAST)
|
|
{
|
|
png_warning(png_ptr, "Unrecognized equation type for pCAL chunk");
|
|
}
|
|
|
|
for (buf = units; *buf; buf++)
|
|
/* Empty loop to move past the units string. */ ;
|
|
|
|
png_debug(3, "Allocating pCAL parameters array\n");
|
|
params = (png_charpp)png_malloc(png_ptr, (png_uint_32)(nparams
|
|
*sizeof(png_charp))) ;
|
|
|
|
/* Get pointers to the start of each parameter string. */
|
|
for (i = 0; i < (int)nparams; i++)
|
|
{
|
|
buf++; /* Skip the null string terminator from previous parameter. */
|
|
|
|
png_debug1(3, "Reading pCAL parameter %d\n", i);
|
|
for (params[i] = buf; *buf != 0x00 && buf <= endptr; buf++)
|
|
/* Empty loop to move past each parameter string */ ;
|
|
|
|
/* Make sure we haven't run out of data yet */
|
|
if (buf > endptr)
|
|
{
|
|
png_warning(png_ptr, "Invalid pCAL data");
|
|
png_free(png_ptr, purpose);
|
|
png_free(png_ptr, params);
|
|
return;
|
|
}
|
|
}
|
|
|
|
png_set_pCAL(png_ptr, info_ptr, purpose, X0, X1, type, nparams,
|
|
units, params);
|
|
|
|
png_free(png_ptr, purpose);
|
|
png_free(png_ptr, params);
|
|
}
|
|
#endif
|
|
|
|
#if defined(PNG_READ_tIME_SUPPORTED)
|
|
void
|
|
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
|
|
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;
|
|
text_ptr->text = text;
|
|
|
|
png_set_text(png_ptr, info_ptr, text_ptr, 1);
|
|
|
|
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
|
|
png_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
|
|
{
|
|
static char msg[] = "Error decoding zTXt chunk";
|
|
png_textp text_ptr;
|
|
png_charp key;
|
|
png_charp text;
|
|
int comp_type = PNG_TEXT_COMPRESSION_NONE;
|
|
png_size_t slength;
|
|
|
|
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
|
|
|
|
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, 0))
|
|
{
|
|
png_free(png_ptr, key);
|
|
return;
|
|
}
|
|
|
|
key[slength] = 0x00;
|
|
|
|
for (text = key; *text; text++)
|
|
/* empty loop */ ;
|
|
|
|
/* zTXt must have some text after the keyword */
|
|
if (text == key + slength)
|
|
{
|
|
png_warning(png_ptr, "Zero length zTXt chunk");
|
|
}
|
|
else if ((comp_type = *(++text)) == PNG_TEXT_COMPRESSION_zTXt)
|
|
{
|
|
png_size_t text_size, key_size;
|
|
text++;
|
|
|
|
png_ptr->zstream.next_in = (png_bytep)text;
|
|
png_ptr->zstream.avail_in = (uInt)(length - (text - key));
|
|
png_ptr->zstream.next_out = png_ptr->zbuf;
|
|
png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
|
|
|
|
key_size = (png_size_t)(text - key);
|
|
text_size = 0;
|
|
text = NULL;
|
|
|
|
while (png_ptr->zstream.avail_in)
|
|
{
|
|
int ret;
|
|
|
|
ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
|
|
if (ret != Z_OK && ret != Z_STREAM_END)
|
|
{
|
|
if (png_ptr->zstream.msg != NULL)
|
|
png_warning(png_ptr, png_ptr->zstream.msg);
|
|
else
|
|
png_warning(png_ptr, msg);
|
|
inflateReset(&png_ptr->zstream);
|
|
png_ptr->zstream.avail_in = 0;
|
|
|
|
if (text == NULL)
|
|
{
|
|
text_size = key_size + sizeof(msg) + 1;
|
|
text = (png_charp)png_malloc(png_ptr, (png_uint_32)text_size);
|
|
png_memcpy(text, key, key_size);
|
|
}
|
|
|
|
text[text_size - 1] = 0x00;
|
|
|
|
/* Copy what we can of the error message into the text chunk */
|
|
text_size = (png_size_t)(slength - (text - key) - 1);
|
|
text_size = sizeof(msg) > text_size ? text_size : sizeof(msg);
|
|
png_memcpy(text + key_size, msg, text_size + 1);
|
|
break;
|
|
}
|
|
if (!png_ptr->zstream.avail_out || ret == Z_STREAM_END)
|
|
{
|
|
if (text == NULL)
|
|
{
|
|
text = (png_charp)png_malloc(png_ptr,
|
|
(png_uint_32)(png_ptr->zbuf_size - png_ptr->zstream.avail_out
|
|
+ key_size + 1));
|
|
png_memcpy(text + key_size, png_ptr->zbuf,
|
|
png_ptr->zbuf_size - png_ptr->zstream.avail_out);
|
|
png_memcpy(text, key, key_size);
|
|
text_size = key_size + png_ptr->zbuf_size -
|
|
png_ptr->zstream.avail_out;
|
|
*(text + text_size) = 0x00;
|
|
}
|
|
else
|
|
{
|
|
png_charp tmp;
|
|
|
|
tmp = text;
|
|
text = (png_charp)png_malloc(png_ptr, (png_uint_32)(text_size +
|
|
png_ptr->zbuf_size - png_ptr->zstream.avail_out + 1));
|
|
png_memcpy(text, tmp, text_size);
|
|
png_free(png_ptr, tmp);
|
|
png_memcpy(text + text_size, png_ptr->zbuf,
|
|
(png_ptr->zbuf_size - png_ptr->zstream.avail_out));
|
|
text_size += png_ptr->zbuf_size - png_ptr->zstream.avail_out;
|
|
*(text + text_size) = 0x00;
|
|
}
|
|
if (ret != Z_STREAM_END)
|
|
{
|
|
png_ptr->zstream.next_out = png_ptr->zbuf;
|
|
png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
|
|
}
|
|
else
|
|
{
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
inflateReset(&png_ptr->zstream);
|
|
png_ptr->zstream.avail_in = 0;
|
|
|
|
png_free(png_ptr, key);
|
|
key = text;
|
|
text += key_size;
|
|
}
|
|
else /* if (comp_type >= PNG_TEXT_COMPRESSION_LAST) */
|
|
{
|
|
png_size_t text_size;
|
|
#if !defined(PNG_NO_STDIO)
|
|
char umsg[50];
|
|
|
|
sprintf(umsg, "Unknown zTXt compression type %d", comp_type);
|
|
png_warning(png_ptr, umsg);
|
|
#else
|
|
png_warning(png_ptr, "Unknown zTXt compression type");
|
|
#endif
|
|
|
|
/* Copy what we can of the error message into the text chunk */
|
|
text_size = (png_size_t)(slength - (text - key) - 1);
|
|
text_size = sizeof(msg) > text_size ? text_size : sizeof(msg);
|
|
png_memcpy(text, msg, text_size + 1);
|
|
}
|
|
|
|
text_ptr = (png_textp)png_malloc(png_ptr, (png_uint_32)sizeof(png_text));
|
|
text_ptr->compression = comp_type;
|
|
text_ptr->key = key;
|
|
text_ptr->text = text;
|
|
|
|
png_set_text(png_ptr, info_ptr, text_ptr, 1);
|
|
|
|
png_free(png_ptr, text_ptr);
|
|
}
|
|
#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. */
|
|
void
|
|
png_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
|
|
{
|
|
png_debug(1, "in png_handle_unknown\n");
|
|
|
|
/* In the future we can have code here that calls user-supplied
|
|
* callback functions for unknown chunks before they are ignored or
|
|
* cause an error.
|
|
*/
|
|
png_check_chunk_name(png_ptr, png_ptr->chunk_name);
|
|
|
|
if (!(png_ptr->chunk_name[0] & 0x20))
|
|
{
|
|
png_chunk_error(png_ptr, "unknown critical chunk");
|
|
|
|
/* to quiet compiler warnings about unused info_ptr */
|
|
if (info_ptr == NULL)
|
|
return;
|
|
}
|
|
|
|
if (png_ptr->mode & PNG_HAVE_IDAT)
|
|
png_ptr->mode |= PNG_AFTER_IDAT;
|
|
|
|
png_crc_finish(png_ptr, length);
|
|
|
|
}
|
|
|
|
/* 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
|
|
png_check_chunk_name(png_structp png_ptr, png_bytep chunk_name)
|
|
{
|
|
png_debug(1, "in png_check_chunk_name\n");
|
|
if (isnonalpha(chunk_name[0]) || isnonalpha(chunk_name[1]) ||
|
|
isnonalpha(chunk_name[2]) || isnonalpha(chunk_name[3]))
|
|
{
|
|
png_chunk_error(png_ptr, "invalid chunk type");
|
|
}
|
|
}
|
|
|
|
/* Combines the row recently read in with the existing pixels in the
|
|
row. This routine takes care of alpha and transparency if requested.
|
|
This routine also handles the two methods of progressive display
|
|
of interlaced images, depending on the mask value.
|
|
The mask value describes which pixels are to be combined with
|
|
the row. The pattern always repeats every 8 pixels, so just 8
|
|
bits are needed. A one indicates the pixel is to be combined,
|
|
a zero indicates the pixel is to be skipped. This is in addition
|
|
to any alpha or transparency value associated with the pixel. If
|
|
you want all pixels to be combined, pass 0xff (255) in mask. */
|
|
void
|
|
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) & 0x1;
|
|
*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) & 0x3;
|
|
*dp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff);
|
|
*dp |= (png_byte)(value << shift);
|
|
}
|
|
|
|
if (shift == s_end)
|
|
{
|
|
shift = s_start;
|
|
sp++;
|
|
dp++;
|
|
}
|
|
else
|
|
shift += s_inc;
|
|
if (m == 1)
|
|
m = 0x80;
|
|
else
|
|
m >>= 1;
|
|
}
|
|
break;
|
|
}
|
|
case 4:
|
|
{
|
|
png_bytep sp = png_ptr->row_buf + 1;
|
|
png_bytep dp = row;
|
|
int s_start, s_end, s_inc;
|
|
int m = 0x80;
|
|
int shift;
|
|
png_uint_32 i;
|
|
png_uint_32 row_width = png_ptr->width;
|
|
int value;
|
|
|
|
#if defined(PNG_READ_PACKSWAP_SUPPORTED)
|
|
if (png_ptr->transformations & PNG_PACKSWAP)
|
|
{
|
|
s_start = 0;
|
|
s_end = 4;
|
|
s_inc = 4;
|
|
}
|
|
else
|
|
#endif
|
|
{
|
|
s_start = 4;
|
|
s_end = 0;
|
|
s_inc = -4;
|
|
}
|
|
shift = s_start;
|
|
|
|
for (i = 0; i < row_width; i++)
|
|
{
|
|
if (m & mask)
|
|
{
|
|
value = (*sp >> shift) & 0xf;
|
|
*dp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff);
|
|
*dp |= (png_byte)(value << shift);
|
|
}
|
|
|
|
if (shift == s_end)
|
|
{
|
|
shift = s_start;
|
|
sp++;
|
|
dp++;
|
|
}
|
|
else
|
|
shift += s_inc;
|
|
if (m == 1)
|
|
m = 0x80;
|
|
else
|
|
m >>= 1;
|
|
}
|
|
break;
|
|
}
|
|
default:
|
|
{
|
|
png_bytep sp = png_ptr->row_buf + 1;
|
|
png_bytep dp = row;
|
|
png_size_t pixel_bytes = (png_ptr->row_info.pixel_depth >> 3);
|
|
png_uint_32 i;
|
|
png_uint_32 row_width = png_ptr->width;
|
|
png_byte m = 0x80;
|
|
|
|
|
|
for (i = 0; i < row_width; i++)
|
|
{
|
|
if (m & mask)
|
|
{
|
|
png_memcpy(dp, sp, pixel_bytes);
|
|
}
|
|
|
|
sp += pixel_bytes;
|
|
dp += pixel_bytes;
|
|
|
|
if (m == 1)
|
|
m = 0x80;
|
|
else
|
|
m >>= 1;
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
#if defined(PNG_READ_INTERLACING_SUPPORTED)
|
|
void
|
|
png_do_read_interlace(png_row_infop row_info, png_bytep row, int pass,
|
|
png_uint_32 transformations)
|
|
{
|
|
png_debug(1,"in png_do_read_interlace\n");
|
|
if (row != NULL && row_info != NULL)
|
|
{
|
|
png_uint_32 final_width;
|
|
|
|
final_width = row_info->width * png_pass_inc[pass];
|
|
|
|
switch (row_info->pixel_depth)
|
|
{
|
|
case 1:
|
|
{
|
|
png_bytep sp = row + (png_size_t)((row_info->width - 1) >> 3);
|
|
png_bytep dp = row + (png_size_t)((final_width - 1) >> 3);
|
|
int sshift, dshift;
|
|
int s_start, s_end, s_inc;
|
|
int jstop = png_pass_inc[pass];
|
|
png_byte v;
|
|
png_uint_32 i;
|
|
int j;
|
|
|
|
#if defined(PNG_READ_PACKSWAP_SUPPORTED)
|
|
if (transformations & PNG_PACKSWAP)
|
|
{
|
|
sshift = (int)((row_info->width + 7) & 7);
|
|
dshift = (int)((final_width + 7) & 7);
|
|
s_start = 7;
|
|
s_end = 0;
|
|
s_inc = -1;
|
|
}
|
|
else
|
|
#endif
|
|
{
|
|
sshift = 7 - (int)((row_info->width + 7) & 7);
|
|
dshift = 7 - (int)((final_width + 7) & 7);
|
|
s_start = 0;
|
|
s_end = 7;
|
|
s_inc = 1;
|
|
}
|
|
|
|
for (i = 0; i < row_info->width; i++)
|
|
{
|
|
v = (png_byte)((*sp >> sshift) & 0x1);
|
|
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) & 3) << 1);
|
|
dshift = (int)(((final_width + 3) & 3) << 1);
|
|
s_start = 6;
|
|
s_end = 0;
|
|
s_inc = -2;
|
|
}
|
|
else
|
|
#endif
|
|
{
|
|
sshift = (int)((3 - ((row_info->width + 3) & 3)) << 1);
|
|
dshift = (int)((3 - ((final_width + 3) & 3)) << 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) & 0x3);
|
|
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) & 1) << 2);
|
|
dshift = (int)(((final_width + 1) & 1) << 2);
|
|
s_start = 4;
|
|
s_end = 0;
|
|
s_inc = -4;
|
|
}
|
|
else
|
|
#endif
|
|
{
|
|
sshift = (int)((1 - ((row_info->width + 1) & 1)) << 2);
|
|
dshift = (int)((1 - ((final_width + 1) & 1)) << 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);
|
|
}
|
|
}
|
|
#endif
|
|
|
|
#ifndef PNG_READ_SLOW_FILTERING
|
|
void
|
|
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 = %d, filter = %d\n", png_ptr->row_number, filter);
|
|
|
|
|
|
switch (filter)
|
|
{
|
|
case PNG_FILTER_VALUE_NONE:
|
|
break;
|
|
case PNG_FILTER_VALUE_SUB:
|
|
{
|
|
png_uint_32 i;
|
|
png_uint_32 istop = row_info->rowbytes;
|
|
png_uint_32 bpp = (row_info->pixel_depth + 7) / 8;
|
|
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) / 8;
|
|
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) / 8;
|
|
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_error(png_ptr, "Bad adaptive filter type");
|
|
break;
|
|
}
|
|
}
|
|
#else /* PNG_READ_SLOW_FILTERING */
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void
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png_read_filter_row(png_structp png_ptr, png_row_infop row_info, png_bytep row,
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png_bytep prev_row, int filter)
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|
{
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png_debug(1, "in png_read_filter_row\n");
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png_debug2(2,"row = %d, filter = %d\n", png_ptr->row_number, filter);
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|
|
|
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switch (filter)
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{
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case PNG_FILTER_VALUE_NONE:
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break;
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|
case PNG_FILTER_VALUE_SUB:
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|
{
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|
png_uint_32 i;
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int bpp = (row_info->pixel_depth + 7) / 8;
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png_bytep rp;
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png_bytep lp;
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|
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for (i = (png_uint_32)bpp, rp = row + bpp, lp = row;
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i < row_info->rowbytes; i++, rp++, lp++)
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{
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*rp = (png_byte)(((int)(*rp) + (int)(*lp)) & 0xff);
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}
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break;
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}
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case PNG_FILTER_VALUE_UP:
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{
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png_uint_32 i;
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png_bytep rp;
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png_bytep pp;
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|
|
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for (i = 0, rp = row, pp = prev_row;
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i < row_info->rowbytes; i++, rp++, pp++)
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{
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*rp = (png_byte)(((int)(*rp) + (int)(*pp)) & 0xff);
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}
|
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break;
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|
}
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case PNG_FILTER_VALUE_AVG:
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|
{
|
|
png_uint_32 i;
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|
int bpp = (row_info->pixel_depth + 7) / 8;
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png_bytep rp;
|
|
png_bytep pp;
|
|
png_bytep lp;
|
|
|
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for (i = 0, rp = row, pp = prev_row;
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i < (png_uint_32)bpp; i++, rp++, pp++)
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{
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*rp = (png_byte)(((int)(*rp) +
|
|
((int)(*pp) / 2)) & 0xff);
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|
}
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for (lp = row; i < row_info->rowbytes; i++, rp++, lp++, pp++)
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{
|
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*rp = (png_byte)(((int)(*rp) +
|
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(int)(*pp + *lp) / 2) & 0xff);
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}
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break;
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|
}
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case PNG_FILTER_VALUE_PAETH:
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|
{
|
|
int bpp = (row_info->pixel_depth + 7) / 8;
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png_uint_32 i;
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png_bytep rp;
|
|
png_bytep pp;
|
|
png_bytep lp;
|
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png_bytep cp;
|
|
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for (i = 0, rp = row, pp = prev_row,
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lp = row - bpp, cp = prev_row - bpp;
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i < row_info->rowbytes; i++, rp++, pp++, lp++, cp++)
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{
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int a, b, c, pa, pb, pc, p;
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|
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b = *pp;
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if (i >= (png_uint_32)bpp)
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{
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c = *cp;
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a = *lp;
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}
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else
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{
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a = c = 0;
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}
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p = a + b - c;
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pa = abs(p - a);
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pb = abs(p - b);
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pc = abs(p - c);
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|
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if (pa <= pb && pa <= pc)
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p = a;
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else if (pb <= pc)
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p = b;
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else
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p = c;
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|
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*rp = (png_byte)(((int)(*rp) + p) & 0xff);
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}
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break;
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}
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default:
|
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png_error(png_ptr, "Bad adaptive filter type");
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|
break;
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}
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|
}
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#endif /* PNG_READ_SLOW_FILTERING */
|
|
|
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void
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png_read_finish_row(png_structp png_ptr)
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|
{
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png_debug(1, "in png_read_finish_row\n");
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png_ptr->row_number++;
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if (png_ptr->row_number < png_ptr->num_rows)
|
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return;
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|
|
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if (png_ptr->interlaced)
|
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{
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png_ptr->row_number = 0;
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png_memset_check(png_ptr, png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
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|
do
|
|
{
|
|
png_ptr->pass++;
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if (png_ptr->pass >= 7)
|
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break;
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|
png_ptr->iwidth = (png_ptr->width +
|
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png_pass_inc[png_ptr->pass] - 1 -
|
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png_pass_start[png_ptr->pass]) /
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png_pass_inc[png_ptr->pass];
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png_ptr->irowbytes = ((png_ptr->iwidth *
|
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(png_uint_32)png_ptr->pixel_depth + 7) >> 3) +1;
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|
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if (!(png_ptr->transformations & PNG_INTERLACE))
|
|
{
|
|
png_ptr->num_rows = (png_ptr->height +
|
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png_pass_yinc[png_ptr->pass] - 1 -
|
|
png_pass_ystart[png_ptr->pass]) /
|
|
png_pass_yinc[png_ptr->pass];
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if (!(png_ptr->num_rows))
|
|
continue;
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|
}
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|
else /* if (png_ptr->transformations & PNG_INTERLACE) */
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|
break;
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|
} while (png_ptr->iwidth == 0);
|
|
|
|
if (png_ptr->pass < 7)
|
|
return;
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|
}
|
|
|
|
if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
|
|
{
|
|
char extra;
|
|
int ret;
|
|
|
|
png_ptr->zstream.next_out = (Byte *)&extra;
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|
png_ptr->zstream.avail_out = (uInt)1;
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|
for(;;)
|
|
{
|
|
if (!(png_ptr->zstream.avail_in))
|
|
{
|
|
while (!png_ptr->idat_size)
|
|
{
|
|
png_byte chunk_length[4];
|
|
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png_crc_finish(png_ptr, 0);
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|
|
|
png_read_data(png_ptr, chunk_length, 4);
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png_ptr->idat_size = png_get_uint_32(chunk_length);
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|
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|
png_reset_crc(png_ptr);
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png_crc_read(png_ptr, png_ptr->chunk_name, 4);
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if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
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|
png_error(png_ptr, "Not enough image data");
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|
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|
}
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png_ptr->zstream.avail_in = (uInt)png_ptr->zbuf_size;
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png_ptr->zstream.next_in = png_ptr->zbuf;
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if (png_ptr->zbuf_size > png_ptr->idat_size)
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png_ptr->zstream.avail_in = (uInt)png_ptr->idat_size;
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png_crc_read(png_ptr, png_ptr->zbuf, png_ptr->zstream.avail_in);
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png_ptr->idat_size -= png_ptr->zstream.avail_in;
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}
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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)
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|
png_error(png_ptr, "Extra compressed data");
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|
png_ptr->mode |= PNG_AFTER_IDAT;
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|
png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
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|
break;
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|
}
|
|
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
|
|
png_read_start_row(png_structp png_ptr)
|
|
{
|
|
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 ((png_ptr->num_trans && (png_ptr->transformations & PNG_EXPAND)) ||
|
|
png_ptr->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
|
|
{
|
|
if (max_pixel_depth <= 16)
|
|
max_pixel_depth = 32;
|
|
else if (max_pixel_depth <= 32)
|
|
max_pixel_depth = 64;
|
|
}
|
|
else
|
|
{
|
|
if (max_pixel_depth <= 8)
|
|
max_pixel_depth = 24;
|
|
else if (max_pixel_depth <= 16)
|
|
max_pixel_depth = 48;
|
|
}
|
|
}
|
|
#endif
|
|
|
|
/* align the width on the next larger 8 pixels. Mainly used
|
|
for interlacing */
|
|
row_bytes = ((png_ptr->width + 7) & ~((png_uint_32)7));
|
|
/* calculate the maximum bytes needed, adding a byte and a pixel
|
|
for safety's sake */
|
|
row_bytes = ((row_bytes * (png_uint_32)max_pixel_depth + 7) >> 3) +
|
|
1 + ((max_pixel_depth + 7) >> 3);
|
|
#ifdef PNG_MAX_MALLOC_64K
|
|
if (row_bytes > (png_uint_32)65536L)
|
|
png_error(png_ptr, "This image requires a row greater than 64KB");
|
|
#endif
|
|
png_ptr->row_buf = (png_bytep)png_malloc(png_ptr, row_bytes);
|
|
|
|
#ifdef PNG_MAX_MALLOC_64K
|
|
if ((png_uint_32)png_ptr->rowbytes + 1 > (png_uint_32)65536L)
|
|
png_error(png_ptr, "This image requires a row greater than 64KB");
|
|
#endif
|
|
png_ptr->prev_row = (png_bytep)png_malloc(png_ptr, (png_uint_32)(
|
|
png_ptr->rowbytes + 1));
|
|
|
|
png_memset_check(png_ptr, png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
|
|
|
|
png_debug1(3, "width = %d,\n", png_ptr->width);
|
|
png_debug1(3, "height = %d,\n", png_ptr->height);
|
|
png_debug1(3, "iwidth = %d,\n", png_ptr->iwidth);
|
|
png_debug1(3, "num_rows = %d\n", png_ptr->num_rows);
|
|
png_debug1(3, "rowbytes = %d,\n", png_ptr->rowbytes);
|
|
png_debug1(3, "irowbytes = %d,\n", png_ptr->irowbytes);
|
|
|
|
png_ptr->flags |= PNG_FLAG_ROW_INIT;
|
|
}
|
|
|