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
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
|
/*
* 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 cabac.c
* Context Adaptive Binary Arithmetic Coder.
*/
#include <string.h>
#include "common.h"
#include "bitstream.h"
#include "cabac.h"
static const uint8_t lps_range[64][4]= {
{128,176,208,240}, {128,167,197,227}, {128,158,187,216}, {123,150,178,205},
{116,142,169,195}, {111,135,160,185}, {105,128,152,175}, {100,122,144,166},
{ 95,116,137,158}, { 90,110,130,150}, { 85,104,123,142}, { 81, 99,117,135},
{ 77, 94,111,128}, { 73, 89,105,122}, { 69, 85,100,116}, { 66, 80, 95,110},
{ 62, 76, 90,104}, { 59, 72, 86, 99}, { 56, 69, 81, 94}, { 53, 65, 77, 89},
{ 51, 62, 73, 85}, { 48, 59, 69, 80}, { 46, 56, 66, 76}, { 43, 53, 63, 72},
{ 41, 50, 59, 69}, { 39, 48, 56, 65}, { 37, 45, 54, 62}, { 35, 43, 51, 59},
{ 33, 41, 48, 56}, { 32, 39, 46, 53}, { 30, 37, 43, 50}, { 29, 35, 41, 48},
{ 27, 33, 39, 45}, { 26, 31, 37, 43}, { 24, 30, 35, 41}, { 23, 28, 33, 39},
{ 22, 27, 32, 37}, { 21, 26, 30, 35}, { 20, 24, 29, 33}, { 19, 23, 27, 31},
{ 18, 22, 26, 30}, { 17, 21, 25, 28}, { 16, 20, 23, 27}, { 15, 19, 22, 25},
{ 14, 18, 21, 24}, { 14, 17, 20, 23}, { 13, 16, 19, 22}, { 12, 15, 18, 21},
{ 12, 14, 17, 20}, { 11, 14, 16, 19}, { 11, 13, 15, 18}, { 10, 12, 15, 17},
{ 10, 12, 14, 16}, { 9, 11, 13, 15}, { 9, 11, 12, 14}, { 8, 10, 12, 14},
{ 8, 9, 11, 13}, { 7, 9, 11, 12}, { 7, 9, 10, 12}, { 7, 8, 10, 11},
{ 6, 8, 9, 11}, { 6, 7, 9, 10}, { 6, 7, 8, 9}, { 2, 2, 2, 2},
};
uint8_t ff_h264_mlps_state[4*64];
uint8_t ff_h264_lps_range[4*2*64];
uint8_t ff_h264_lps_state[2*64];
uint8_t ff_h264_mps_state[2*64];
static const uint8_t mps_state[64]= {
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,
57,58,59,60,61,62,62,63,
};
static const uint8_t lps_state[64]= {
0, 0, 1, 2, 2, 4, 4, 5,
6, 7, 8, 9, 9,11,11,12,
13,13,15,15,16,16,18,18,
19,19,21,21,22,22,23,24,
24,25,26,26,27,27,28,29,
29,30,30,30,31,32,32,33,
33,33,34,34,35,35,35,36,
36,36,37,37,37,38,38,63,
};
#if 0
const uint8_t ff_h264_norm_shift_old[128]= {
7,6,5,5,4,4,4,4,3,3,3,3,3,3,3,3,
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,
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,
};
#endif
const uint8_t ff_h264_norm_shift[512]= {
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,
};
/**
*
* @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;
#ifdef STRICT_LIMITS
c->sym_count =0;
#endif
c->pb.bit_left++; //avoids firstBitFlag
}
/**
*
* @param buf_size size of buf in bits
*/
void 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;
#else
c->low = (*c->bytestream++)<<10;
#endif
c->low+= ((*c->bytestream++)<<2) + 2;
c->range= 0x1FE;
}
void ff_init_cabac_states(CABACContext *c){
int i, j;
for(i=0; i<64; i++){
for(j=0; j<4; j++){ //FIXME check if this is worth the 1 shift we save
ff_h264_lps_range[j*2*64+2*i+0]=
ff_h264_lps_range[j*2*64+2*i+1]= lps_range[i][j];
}
ff_h264_mlps_state[128+2*i+0]=
ff_h264_mps_state[2*i+0]= 2*mps_state[i]+0;
ff_h264_mlps_state[128+2*i+1]=
ff_h264_mps_state[2*i+1]= 2*mps_state[i]+1;
if( i ){
#ifdef BRANCHLESS_CABAC_DECODER
ff_h264_mlps_state[128-2*i-1]= 2*lps_state[i]+0;
ff_h264_mlps_state[128-2*i-2]= 2*lps_state[i]+1;
}else{
ff_h264_mlps_state[128-2*i-1]= 1;
ff_h264_mlps_state[128-2*i-2]= 0;
#else
ff_h264_lps_state[2*i+0]= 2*lps_state[i]+0;
ff_h264_lps_state[2*i+1]= 2*lps_state[i]+1;
}else{
ff_h264_lps_state[2*i+0]= 1;
ff_h264_lps_state[2*i+1]= 0;
#endif
}
}
}
#if 0 //selftest
#undef random
#define SIZE 10240
#include "avcodec.h"
int main(void){
CABACContext c;
uint8_t b[9*SIZE];
uint8_t r[9*SIZE];
int i;
uint8_t state[10]= {0};
ff_init_cabac_encoder(&c, b, SIZE);
ff_init_cabac_states(&c, ff_h264_lps_range, ff_h264_mps_state, ff_h264_lps_state, 64);
for(i=0; i<SIZE; i++){
r[i]= random()%7;
}
for(i=0; i<SIZE; i++){
START_TIMER
put_cabac_bypass(&c, r[i]&1);
STOP_TIMER("put_cabac_bypass")
}
for(i=0; i<SIZE; i++){
START_TIMER
put_cabac(&c, state, r[i]&1);
STOP_TIMER("put_cabac")
}
for(i=0; i<SIZE; i++){
START_TIMER
put_cabac_u(&c, state, r[i], 6, 3, i&1);
STOP_TIMER("put_cabac_u")
}
for(i=0; i<SIZE; i++){
START_TIMER
put_cabac_ueg(&c, state, r[i], 3, 0, 1, 2);
STOP_TIMER("put_cabac_ueg")
}
put_cabac_terminate(&c, 1);
ff_init_cabac_decoder(&c, b, SIZE);
memset(state, 0, sizeof(state));
for(i=0; i<SIZE; i++){
START_TIMER
if( (r[i]&1) != get_cabac_bypass(&c) )
av_log(NULL, AV_LOG_ERROR, "CABAC bypass failure at %d\n", i);
STOP_TIMER("get_cabac_bypass")
}
for(i=0; i<SIZE; i++){
START_TIMER
if( (r[i]&1) != get_cabac(&c, state) )
av_log(NULL, AV_LOG_ERROR, "CABAC failure at %d\n", i);
STOP_TIMER("get_cabac")
}
#if 0
for(i=0; i<SIZE; i++){
START_TIMER
if( r[i] != get_cabac_u(&c, state, (i&1) ? 6 : 7, 3, i&1) )
av_log(NULL, AV_LOG_ERROR, "CABAC unary (truncated) binarization failure at %d\n", i);
STOP_TIMER("get_cabac_u")
}
for(i=0; i<SIZE; i++){
START_TIMER
if( r[i] != get_cabac_ueg(&c, state, 3, 0, 1, 2))
av_log(NULL, AV_LOG_ERROR, "CABAC unary (truncated) binarization failure at %d\n", i);
STOP_TIMER("get_cabac_ueg")
}
#endif
if(!get_cabac_terminate(&c))
av_log(NULL, AV_LOG_ERROR, "where's the Terminator?\n");
return 0;
}
#endif
|
