1/*
2 * PNG image format
3 * Copyright (c) 2003 Fabrice Bellard
4 *
5 * This file is part of FFmpeg.
6 *
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.
11 *
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.
16 *
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
20 */
21
22#ifndef AVCODEC_PNG_H
23#define AVCODEC_PNG_H
24
25#include <stdint.h>
26
27#define PNG_COLOR_MASK_PALETTE    1
28#define PNG_COLOR_MASK_COLOR      2
29#define PNG_COLOR_MASK_ALPHA      4
30
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)
36
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
44
45#define PNG_IHDR      0x0001
46#define PNG_IDAT      0x0002
47#define PNG_ALLIMAGE  0x0004
48#define PNG_PLTE      0x0008
49
50#define NB_PASSES 7
51
52extern const uint8_t ff_pngsig[8];
53extern const uint8_t ff_mngsig[8];
54
55/* Mask to determine which y pixels are valid in a pass */
56extern const uint8_t ff_png_pass_ymask[NB_PASSES];
57
58/* minimum x value */
59extern const uint8_t ff_png_pass_xmin[NB_PASSES];
60
61/* x shift to get row width */
62extern const uint8_t ff_png_pass_xshift[NB_PASSES];
63
64/* Mask to determine which pixels are valid in a pass */
65extern const uint8_t ff_png_pass_mask[NB_PASSES];
66
67void *ff_png_zalloc(void *opaque, unsigned int items, unsigned int size);
68
69void ff_png_zfree(void *opaque, void *ptr);
70
71int ff_png_get_nb_channels(int color_type);
72
73/* compute the row size of an interleaved pass */
74int ff_png_pass_row_size(int pass, int bits_per_pixel, int width);
75
76void ff_add_png_paeth_prediction(uint8_t *dst, uint8_t *src, uint8_t *top, int w, int bpp);
77
78#endif /* AVCODEC_PNG_H */
79