3 * Copyright (c) 2003 Fabrice Bellard
5 * This file is part of FFmpeg.
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
27 #define PNG_COLOR_MASK_PALETTE 1
28 #define PNG_COLOR_MASK_COLOR 2
29 #define PNG_COLOR_MASK_ALPHA 4
31 #define PNG_COLOR_TYPE_GRAY 0
32 #define PNG_COLOR_TYPE_PALETTE (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE)
33 #define PNG_COLOR_TYPE_RGB (PNG_COLOR_MASK_COLOR)
34 #define PNG_COLOR_TYPE_RGB_ALPHA (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA)
35 #define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA)
37 #define PNG_FILTER_TYPE_LOCO 64
38 #define PNG_FILTER_VALUE_NONE 0
39 #define PNG_FILTER_VALUE_SUB 1
40 #define PNG_FILTER_VALUE_UP 2
41 #define PNG_FILTER_VALUE_AVG 3
42 #define PNG_FILTER_VALUE_PAETH 4
43 #define PNG_FILTER_VALUE_MIXED 5
45 #define PNG_IHDR 0x0001
46 #define PNG_IDAT 0x0002
47 #define PNG_ALLIMAGE 0x0004
48 #define PNG_PLTE 0x0008
52 #define PNGSIG 0x89504e470d0a1a0a
53 #define MNGSIG 0x8a4d4e470d0a1a0a
55 /* Mask to determine which y pixels are valid in a pass */
56 extern const uint8_t ff_png_pass_ymask
[NB_PASSES
];
58 void *ff_png_zalloc(void *opaque
, unsigned int items
, unsigned int size
);
60 void ff_png_zfree(void *opaque
, void *ptr
);
62 int ff_png_get_nb_channels(int color_type
);
64 /* compute the row size of an interleaved pass */
65 int ff_png_pass_row_size(int pass
, int bits_per_pixel
, int width
);
67 void ff_add_png_paeth_prediction(uint8_t *dst
, uint8_t *src
, uint8_t *top
, int w
, int bpp
);
69 #endif /* AVCODEC_PNG_H */