FFmpeg
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 extern const uint8_t ff_h264_cabac_tables[512 + 4*2*64 + 4*64 + 63];
35 #define H264_NORM_SHIFT_OFFSET 0
36 #define H264_LPS_RANGE_OFFSET 512
37 #define H264_MLPS_STATE_OFFSET 1024
38 #define H264_LAST_COEFF_FLAG_OFFSET_8x8_OFFSET 1280
39 
40 #define CABAC_BITS 16
41 #define CABAC_MASK ((1<<CABAC_BITS)-1)
42 
43 typedef struct CABACContext{
44  int low;
45  int range;
52 
53 void ff_init_cabac_encoder(CABACContext *c, uint8_t *buf, int buf_size);
54 int ff_init_cabac_decoder(CABACContext *c, const uint8_t *buf, int buf_size);
55 
56 #endif /* AVCODEC_CABAC_H */
const uint8_t * bytestream_end
Definition: cabac.h:49
void ff_init_cabac_encoder(CABACContext *c, uint8_t *buf, int buf_size)
Definition: cabac.c:164
const uint8_t * bytestream
Definition: cabac.h:48
uint8_t
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
Definition: undefined.txt:32
const uint8_t * bytestream_start
Definition: cabac.h:47
int outstanding_count
Definition: cabac.h:46
void * buf
Definition: avisynth_c.h:766
int range
Definition: cabac.h:45
PutBitContext pb
Definition: cabac.h:50
int low
Definition: cabac.h:44
const uint8_t ff_h264_cabac_tables[512+4 *2 *64+4 *64+63]
int ff_init_cabac_decoder(CABACContext *c, const uint8_t *buf, int buf_size)
Definition: cabac.c:177
bitstream writer API