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/*
* PNG image format
* Copyright (c) 2003 Fabrice Bellard.
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef AVCODEC_PNG_H
#define AVCODEC_PNG_H
#include <stdint.h>
#include <zlib.h>
#define PNG_COLOR_MASK_PALETTE 1
#define PNG_COLOR_MASK_COLOR 2
#define PNG_COLOR_MASK_ALPHA 4
#define PNG_COLOR_TYPE_GRAY 0
#define PNG_COLOR_TYPE_PALETTE (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE)
#define PNG_COLOR_TYPE_RGB (PNG_COLOR_MASK_COLOR)
#define PNG_COLOR_TYPE_RGB_ALPHA (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA)
#define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA)
#define PNG_FILTER_VALUE_NONE 0
#define PNG_FILTER_VALUE_SUB 1
#define PNG_FILTER_VALUE_UP 2
#define PNG_FILTER_VALUE_AVG 3
#define PNG_FILTER_VALUE_PAETH 4
#define PNG_IHDR 0x0001
#define PNG_IDAT 0x0002
#define PNG_ALLIMAGE 0x0004
#define PNG_PLTE 0x0008
#define NB_PASSES 7
#define IOBUF_SIZE 4096
typedef struct PNGContext {
uint8_t *bytestream;
uint8_t *bytestream_start;
uint8_t *bytestream_end;
AVFrame picture;
int state;
int width, height;
int bit_depth;
int color_type;
int compression_type;
int interlace_type;
int filter_type;
int channels;
int bits_per_pixel;
int bpp;
uint8_t *image_buf;
int image_linesize;
uint32_t palette[256];
uint8_t *crow_buf;
uint8_t *last_row;
uint8_t *tmp_row;
int pass;
int crow_size; /* compressed row size (include filter type) */
int row_size; /* decompressed row size */
int pass_row_size; /* decompress row size of the current pass */
int y;
z_stream zstream;
uint8_t buf[IOBUF_SIZE];
} PNGContext;
extern const uint8_t ff_pngsig[8];
/* Mask to determine which y pixels are valid in a pass */
extern const uint8_t ff_png_pass_ymask[NB_PASSES];
/* minimum x value */
extern const uint8_t ff_png_pass_xmin[NB_PASSES];
/* x shift to get row width */
extern const uint8_t ff_png_pass_xshift[NB_PASSES];
/* Mask to determine which pixels are valid in a pass */
extern const uint8_t ff_png_pass_mask[NB_PASSES];
extern void *ff_png_zalloc(void *opaque, unsigned int items,
unsigned int size);
extern void ff_png_zfree(void *opaque, void *ptr);
extern int ff_png_get_nb_channels(int color_type);
/* compute the row size of an interleaved pass */
extern int ff_png_pass_row_size(int pass, int bits_per_pixel, int width);
extern int ff_png_common_init(AVCodecContext *avctx);
#endif
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