Chiebot-Mirror
/
FFmpeg
mirror of https://github.com/FFmpeg/FFmpeg.git
8
0
Fork 0
Code Issues Projects Releases Wiki Activity
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
86637 Commits
37 Branches
400 Tags
465 MiB
 
 
 
 
Tag: Branch: Tree: 5659f74047
Branches Tags
${ item.name }
Create tag ${ searchTerm }
Create branch ${ searchTerm }
from '5659f74047'
${ noResults }
FFmpeg/libavcodec/cabac.c

202 lines
10 KiB
Raw Blame History

/*
* H.26L/H.264/AVC/JVT/14496-10/... encoder/decoder
* Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* Context Adaptive Binary Arithmetic Coder.
*/
#include <string.h>
#include "libavutil/common.h"
#include "libavutil/timer.h"
#include "cabac.h"
#include "cabac_functions.h"
const uint8_t ff_h264_cabac_tables[512 + 4*2*64 + 4*64 + 63] = {
9,8,7,7,6,6,6,6,5,5,5,5,5,5,5,5,
4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,
3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,
3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,
2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
// LPS range
-128, -128, -128, -128, -128, -128, 123, 123,
116, 116, 111, 111, 105, 105, 100, 100,
95, 95, 90, 90, 85, 85, 81, 81,
77, 77, 73, 73, 69, 69, 66, 66,
62, 62, 59, 59, 56, 56, 53, 53,
51, 51, 48, 48, 46, 46, 43, 43,
41, 41, 39, 39, 37, 37, 35, 35,
33, 33, 32, 32, 30, 30, 29, 29,
27, 27, 26, 26, 24, 24, 23, 23,
22, 22, 21, 21, 20, 20, 19, 19,
18, 18, 17, 17, 16, 16, 15, 15,
14, 14, 14, 14, 13, 13, 12, 12,
12, 12, 11, 11, 11, 11, 10, 10,
10, 10, 9, 9, 9, 9, 8, 8,
8, 8, 7, 7, 7, 7, 7, 7,
6, 6, 6, 6, 6, 6, 2, 2,
-80, -80, -89, -89, -98, -98, -106, -106,
-114, -114, -121, -121, -128, -128, 122, 122,
116, 116, 110, 110, 104, 104, 99, 99,
94, 94, 89, 89, 85, 85, 80, 80,
76, 76, 72, 72, 69, 69, 65, 65,
62, 62, 59, 59, 56, 56, 53, 53,
50, 50, 48, 48, 45, 45, 43, 43,
41, 41, 39, 39, 37, 37, 35, 35,
33, 33, 31, 31, 30, 30, 28, 28,
27, 27, 26, 26, 24, 24, 23, 23,
22, 22, 21, 21, 20, 20, 19, 19,
18, 18, 17, 17, 16, 16, 15, 15,
14, 14, 14, 14, 13, 13, 12, 12,
12, 12, 11, 11, 11, 11, 10, 10,
9, 9, 9, 9, 9, 9, 8, 8,
8, 8, 7, 7, 7, 7, 2, 2,
-48, -48, -59, -59, -69, -69, -78, -78,
-87, -87, -96, -96, -104, -104, -112, -112,
-119, -119, -126, -126, 123, 123, 117, 117,
111, 111, 105, 105, 100, 100, 95, 95,
90, 90, 86, 86, 81, 81, 77, 77,
73, 73, 69, 69, 66, 66, 63, 63,
59, 59, 56, 56, 54, 54, 51, 51,
48, 48, 46, 46, 43, 43, 41, 41,
39, 39, 37, 37, 35, 35, 33, 33,
32, 32, 30, 30, 29, 29, 27, 27,
26, 26, 25, 25, 23, 23, 22, 22,
21, 21, 20, 20, 19, 19, 18, 18,
17, 17, 16, 16, 15, 15, 15, 15,
14, 14, 13, 13, 12, 12, 12, 12,
11, 11, 11, 11, 10, 10, 10, 10,
9, 9, 9, 9, 8, 8, 2, 2,
-16, -16, -29, -29, -40, -40, -51, -51,
-61, -61, -71, -71, -81, -81, -90, -90,
-98, -98, -106, -106, -114, -114, -121, -121,
-128, -128, 122, 122, 116, 116, 110, 110,
104, 104, 99, 99, 94, 94, 89, 89,
85, 85, 80, 80, 76, 76, 72, 72,
69, 69, 65, 65, 62, 62, 59, 59,
56, 56, 53, 53, 50, 50, 48, 48,
45, 45, 43, 43, 41, 41, 39, 39,
37, 37, 35, 35, 33, 33, 31, 31,
30, 30, 28, 28, 27, 27, 25, 25,
24, 24, 23, 23, 22, 22, 21, 21,
20, 20, 19, 19, 18, 18, 17, 17,
16, 16, 15, 15, 14, 14, 14, 14,
13, 13, 12, 12, 12, 12, 11, 11,
11, 11, 10, 10, 9, 9, 2, 2,
// mlps state
127, 126, 77, 76, 77, 76, 75, 74,
75, 74, 75, 74, 73, 72, 73, 72,
73, 72, 71, 70, 71, 70, 71, 70,
69, 68, 69, 68, 67, 66, 67, 66,
67, 66, 65, 64, 65, 64, 63, 62,
61, 60, 61, 60, 61, 60, 59, 58,
59, 58, 57, 56, 55, 54, 55, 54,
53, 52, 53, 52, 51, 50, 49, 48,
49, 48, 47, 46, 45, 44, 45, 44,
43, 42, 43, 42, 39, 38, 39, 38,
37, 36, 37, 36, 33, 32, 33, 32,
31, 30, 31, 30, 27, 26, 27, 26,
25, 24, 23, 22, 23, 22, 19, 18,
19, 18, 17, 16, 15, 14, 13, 12,
11, 10, 9, 8, 9, 8, 5, 4,
5, 4, 3, 2, 1, 0, 0, 1,
2, 3, 4, 5, 6, 7, 8, 9,
10, 11, 12, 13, 14, 15, 16, 17,
18, 19, 20, 21, 22, 23, 24, 25,
26, 27, 28, 29, 30, 31, 32, 33,
34, 35, 36, 37, 38, 39, 40, 41,
42, 43, 44, 45, 46, 47, 48, 49,
50, 51, 52, 53, 54, 55, 56, 57,
58, 59, 60, 61, 62, 63, 64, 65,
66, 67, 68, 69, 70, 71, 72, 73,
74, 75, 76, 77, 78, 79, 80, 81,
82, 83, 84, 85, 86, 87, 88, 89,
90, 91, 92, 93, 94, 95, 96, 97,
98, 99, 100, 101, 102, 103, 104, 105,
106, 107, 108, 109, 110, 111, 112, 113,
114, 115, 116, 117, 118, 119, 120, 121,
122, 123, 124, 125, 124, 125, 126, 127,
// last_coeff_flag_offset_8x8
0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4,
5, 5, 5, 5, 6, 6, 6, 6, 7, 7, 7, 7, 8, 8, 8
};
/**
* @param buf_size size of buf in bits
*/
void ff_init_cabac_encoder(CABACContext *c, uint8_t *buf, int buf_size){
init_put_bits(&c->pb, buf, buf_size);
c->low= 0;
c->range= 0x1FE;
c->outstanding_count= 0;
c->pb.bit_left++; //avoids firstBitFlag
}
/**
*
* @param buf_size size of buf in bits
*/
int ff_init_cabac_decoder(CABACContext *c, const uint8_t *buf, int buf_size){
c->bytestream_start=
c->bytestream= buf;
c->bytestream_end= buf + buf_size;
#if CABAC_BITS == 16
c->low = (*c->bytestream++)<<18;
c->low+= (*c->bytestream++)<<10;
// Keep our fetches on a 2-byte boundary as this should avoid ever having to
// do unaligned loads if the compiler (or asm) optimises the double byte
// load into a single instruction
if(((uintptr_t)c->bytestream & 1) == 0) {
c->low += (1 << 9);
}
else {
c->low += ((*c->bytestream++) << 2) + 2;
}
#else
c->low = (*c->bytestream++)<<10;
c->low+= ((*c->bytestream++)<<2) + 2;
#endif
c->range= 0x1FE;
if ((c->range<<(CABAC_BITS+1)) < c->low)
return AVERROR_INVALIDDATA;
return 0;
}