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libavcodec/png.h

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00001 /*
00002  * PNG image format
00003  * Copyright (c) 2003 Fabrice Bellard
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * FFmpeg is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with FFmpeg; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00022 #ifndef AVCODEC_PNG_H
00023 #define AVCODEC_PNG_H
00024 
00025 #include <stdint.h>
00026 #include <zlib.h>
00027 
00028 #include "avcodec.h"
00029 
00030 #define PNG_COLOR_MASK_PALETTE    1
00031 #define PNG_COLOR_MASK_COLOR      2
00032 #define PNG_COLOR_MASK_ALPHA      4
00033 
00034 #define PNG_COLOR_TYPE_GRAY 0
00035 #define PNG_COLOR_TYPE_PALETTE  (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE)
00036 #define PNG_COLOR_TYPE_RGB        (PNG_COLOR_MASK_COLOR)
00037 #define PNG_COLOR_TYPE_RGB_ALPHA  (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA)
00038 #define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA)
00039 
00040 #define PNG_FILTER_TYPE_LOCO   64
00041 #define PNG_FILTER_VALUE_NONE  0
00042 #define PNG_FILTER_VALUE_SUB   1
00043 #define PNG_FILTER_VALUE_UP    2
00044 #define PNG_FILTER_VALUE_AVG   3
00045 #define PNG_FILTER_VALUE_PAETH 4
00046 #define PNG_FILTER_VALUE_MIXED 5
00047 
00048 #define PNG_IHDR      0x0001
00049 #define PNG_IDAT      0x0002
00050 #define PNG_ALLIMAGE  0x0004
00051 #define PNG_PLTE      0x0008
00052 
00053 #define NB_PASSES 7
00054 
00055 extern const uint8_t ff_pngsig[8];
00056 extern const uint8_t ff_mngsig[8];
00057 
00058 /* Mask to determine which y pixels are valid in a pass */
00059 extern const uint8_t ff_png_pass_ymask[NB_PASSES];
00060 
00061 /* Mask to determine which pixels are valid in a pass */
00062 extern const uint8_t ff_png_pass_mask[NB_PASSES];
00063 
00064 void *ff_png_zalloc(void *opaque, unsigned int items, unsigned int size);
00065 
00066 void ff_png_zfree(void *opaque, void *ptr);
00067 
00068 int ff_png_get_nb_channels(int color_type);
00069 
00070 /* compute the row size of an interleaved pass */
00071 int ff_png_pass_row_size(int pass, int bits_per_pixel, int width);
00072 
00073 void ff_add_png_paeth_prediction(uint8_t *dst, uint8_t *src, uint8_t *top, int w, int bpp);
00074 
00075 typedef struct PNGDecContext {
00076     const uint8_t *bytestream;
00077     const uint8_t *bytestream_start;
00078     const uint8_t *bytestream_end;
00079     AVFrame picture1, picture2;
00080     AVFrame *current_picture, *last_picture;
00081 
00082     int state;
00083     int width, height;
00084     int bit_depth;
00085     int color_type;
00086     int compression_type;
00087     int interlace_type;
00088     int filter_type;
00089     int channels;
00090     int bits_per_pixel;
00091     int bpp;
00092 
00093     uint8_t *image_buf;
00094     int image_linesize;
00095     uint32_t palette[256];
00096     uint8_t *crow_buf;
00097     uint8_t *last_row;
00098     uint8_t *tmp_row;
00099     int pass;
00100     int crow_size; /* compressed row size (include filter type) */
00101     int row_size; /* decompressed row size */
00102     int pass_row_size; /* decompress row size of the current pass */
00103     int y;
00104     z_stream zstream;
00105 
00106     void (*add_bytes_l2)(uint8_t *dst, uint8_t *src1, uint8_t *src2, int w);
00107     void (*add_paeth_prediction)(uint8_t *dst, uint8_t *src, uint8_t *top, int w, int bpp);
00108 } PNGDecContext;
00109 
00110 void ff_png_init_mmx(PNGDecContext *s);
00111 
00112 #endif /* AVCODEC_PNG_H */

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