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