FFmpeg
png.h
Go to the documentation of this file.
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 #include "pngdsp.h"
28 
29 #define PNG_COLOR_MASK_PALETTE 1
30 #define PNG_COLOR_MASK_COLOR 2
31 #define PNG_COLOR_MASK_ALPHA 4
32 
33 #define PNG_COLOR_TYPE_GRAY 0
34 #define PNG_COLOR_TYPE_PALETTE (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE)
35 #define PNG_COLOR_TYPE_RGB (PNG_COLOR_MASK_COLOR)
36 #define PNG_COLOR_TYPE_RGB_ALPHA (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA)
37 #define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA)
38 
39 #define PNG_FILTER_TYPE_LOCO 64
40 #define PNG_FILTER_VALUE_NONE 0
41 #define PNG_FILTER_VALUE_SUB 1
42 #define PNG_FILTER_VALUE_UP 2
43 #define PNG_FILTER_VALUE_AVG 3
44 #define PNG_FILTER_VALUE_PAETH 4
45 #define PNG_FILTER_VALUE_MIXED 5
46 
47 #define NB_PASSES 7
48 
49 #define PNGSIG 0x89504e470d0a1a0a
50 #define MNGSIG 0x8a4d4e470d0a1a0a
51 
52 /* Mask to determine which y pixels are valid in a pass */
53 extern const uint8_t ff_png_pass_ymask[NB_PASSES];
54 
55 void *ff_png_zalloc(void *opaque, unsigned int items, unsigned int size);
56 
57 void ff_png_zfree(void *opaque, void *ptr);
58 
59 int ff_png_get_nb_channels(int color_type);
60 
61 /* compute the row size of an interleaved pass */
62 int ff_png_pass_row_size(int pass, int bits_per_pixel, int width);
63 
64 void ff_add_png_paeth_prediction(uint8_t *dst, uint8_t *src, uint8_t *top, int w, int bpp);
65 
66 void ff_png_filter_row(PNGDSPContext *dsp, uint8_t *dst, int filter_type,
67  uint8_t *src, uint8_t *last, int size, int bpp);
68 
69 #endif /* AVCODEC_PNG_H */
void * ff_png_zalloc(void *opaque, unsigned int items, unsigned int size)
Definition: png.c:39
void ff_png_filter_row(PNGDSPContext *dsp, uint8_t *dst, int filter_type, uint8_t *src, uint8_t *last, int size, int bpp)
Definition: pngdec.c:252
uint8_t
ptrdiff_t size
Definition: opengl_enc.c:100
#define src
Definition: vp8dsp.c:255
void ff_png_zfree(void *opaque, void *ptr)
Definition: png.c:44
#define NB_PASSES
Definition: png.h:47
#define pass
Definition: fft_template.c:603
#define width
uint8_t w
Definition: llviddspenc.c:39
const uint8_t ff_png_pass_ymask[NB_PASSES]
Definition: png.c:25
int ff_png_pass_row_size(int pass, int bits_per_pixel, int width)
Definition: png.c:62
int ff_png_get_nb_channels(int color_type)
Definition: png.c:49
void ff_add_png_paeth_prediction(uint8_t *dst, uint8_t *src, uint8_t *top, int w, int bpp)
Definition: pngdec.c:186