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cabac.h
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1 /*
2  * H.26L/H.264/AVC/JVT/14496-10/... encoder/decoder
3  * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
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 /**
23  * @file
24  * Context Adaptive Binary Arithmetic Coder.
25  */
26 
27 #ifndef AVCODEC_CABAC_H
28 #define AVCODEC_CABAC_H
29 
30 #include <stdint.h>
31 
32 #include "put_bits.h"
33 
34 #if CONFIG_HARDCODED_TABLES
35 #define CABAC_TABLE_CONST const
36 #else
37 #define CABAC_TABLE_CONST
38 #endif
39 extern CABAC_TABLE_CONST uint8_t ff_h264_cabac_tables[512 + 4*2*64 + 4*64 + 63];
40 #define H264_NORM_SHIFT_OFFSET 0
41 #define H264_LPS_RANGE_OFFSET 512
42 #define H264_MLPS_STATE_OFFSET 1024
43 #define H264_LAST_COEFF_FLAG_OFFSET_8x8_OFFSET 1280
44 
45 #define CABAC_BITS 16
46 #define CABAC_MASK ((1<<CABAC_BITS)-1)
47 
48 typedef struct CABACContext{
49  int low;
50  int range;
57 
58 void ff_init_cabac_encoder(CABACContext *c, uint8_t *buf, int buf_size);
59 void ff_init_cabac_decoder(CABACContext *c, const uint8_t *buf, int buf_size);
60 void ff_init_cabac_states(void);
61 
62 #endif /* AVCODEC_CABAC_H */