2 * H.26L/H.264/AVC/JVT/14496-10/... encoder/decoder
3 * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
5 * This file is part of FFmpeg.
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.
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.
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
25 * Context Adaptive Binary Arithmetic Coder.
31 #include "bitstream.h"
34 static const uint8_t lps_range[64][4]= {
35 {128,176,208,240}, {128,167,197,227}, {128,158,187,216}, {123,150,178,205},
36 {116,142,169,195}, {111,135,160,185}, {105,128,152,175}, {100,122,144,166},
37 { 95,116,137,158}, { 90,110,130,150}, { 85,104,123,142}, { 81, 99,117,135},
38 { 77, 94,111,128}, { 73, 89,105,122}, { 69, 85,100,116}, { 66, 80, 95,110},
39 { 62, 76, 90,104}, { 59, 72, 86, 99}, { 56, 69, 81, 94}, { 53, 65, 77, 89},
40 { 51, 62, 73, 85}, { 48, 59, 69, 80}, { 46, 56, 66, 76}, { 43, 53, 63, 72},
41 { 41, 50, 59, 69}, { 39, 48, 56, 65}, { 37, 45, 54, 62}, { 35, 43, 51, 59},
42 { 33, 41, 48, 56}, { 32, 39, 46, 53}, { 30, 37, 43, 50}, { 29, 35, 41, 48},
43 { 27, 33, 39, 45}, { 26, 31, 37, 43}, { 24, 30, 35, 41}, { 23, 28, 33, 39},
44 { 22, 27, 32, 37}, { 21, 26, 30, 35}, { 20, 24, 29, 33}, { 19, 23, 27, 31},
45 { 18, 22, 26, 30}, { 17, 21, 25, 28}, { 16, 20, 23, 27}, { 15, 19, 22, 25},
46 { 14, 18, 21, 24}, { 14, 17, 20, 23}, { 13, 16, 19, 22}, { 12, 15, 18, 21},
47 { 12, 14, 17, 20}, { 11, 14, 16, 19}, { 11, 13, 15, 18}, { 10, 12, 15, 17},
48 { 10, 12, 14, 16}, { 9, 11, 13, 15}, { 9, 11, 12, 14}, { 8, 10, 12, 14},
49 { 8, 9, 11, 13}, { 7, 9, 11, 12}, { 7, 9, 10, 12}, { 7, 8, 10, 11},
50 { 6, 8, 9, 11}, { 6, 7, 9, 10}, { 6, 7, 8, 9}, { 2, 2, 2, 2},
53 uint8_t ff_h264_lps_range[2*65][4];
55 const uint8_t ff_h264_mps_state[64]= {
56 1, 2, 3, 4, 5, 6, 7, 8,
57 9,10,11,12,13,14,15,16,
58 17,18,19,20,21,22,23,24,
59 25,26,27,28,29,30,31,32,
60 33,34,35,36,37,38,39,40,
61 41,42,43,44,45,46,47,48,
62 49,50,51,52,53,54,55,56,
63 57,58,59,60,61,62,62,63,
66 const uint8_t ff_h264_lps_state[64]= {
67 0, 0, 1, 2, 2, 4, 4, 5,
68 6, 7, 8, 9, 9,11,11,12,
69 13,13,15,15,16,16,18,18,
70 19,19,21,21,22,22,23,24,
71 24,25,26,26,27,27,28,29,
72 29,30,30,30,31,32,32,33,
73 33,33,34,34,35,35,35,36,
74 36,36,37,37,37,38,38,63,
77 const uint8_t ff_h264_norm_shift[128]= {
78 7,6,5,5,4,4,4,4,3,3,3,3,3,3,3,3,
79 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
80 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
81 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
82 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
83 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
84 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
85 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
90 * @param buf_size size of buf in bits
92 void ff_init_cabac_encoder(CABACContext *c, uint8_t *buf, int buf_size){
93 init_put_bits(&c->pb, buf, buf_size);
97 c->outstanding_count= 0;
102 c->pb.bit_left++; //avoids firstBitFlag
107 * @param buf_size size of buf in bits
109 void ff_init_cabac_decoder(CABACContext *c, const uint8_t *buf, int buf_size){
112 c->bytestream_end= buf + buf_size;
115 c->low = (*c->bytestream++)<<18;
116 c->low+= (*c->bytestream++)<<10;
118 c->low = (*c->bytestream++)<<10;
120 c->low+= ((*c->bytestream++)<<2) + 2;
121 c->range= 0x1FE<<(CABAC_BITS + 1);
124 void ff_init_cabac_states(CABACContext *c,
125 uint8_t const *mps_state, uint8_t const *lps_state, int state_count){
128 for(i=0; i<state_count; i++){
129 for(j=0; j<4; j++){ //FIXME check if this is worth the 1 shift we save
130 ff_h264_lps_range[2*i+0][j+4]=
131 ff_h264_lps_range[2*i+1][j+4]= lps_range[i][j];
134 c->mps_state[2*i+0]= 2*mps_state[i]+0;
135 c->mps_state[2*i+1]= 2*mps_state[i]+1;
138 #ifdef BRANCHLESS_CABAC_DECODER
139 c->mps_state[-2*i-1]= 2*lps_state[i]+0; //FIXME yes this is not valid C but iam lazy, cleanup welcome
140 c->mps_state[-2*i-2]= 2*lps_state[i]+1;
142 c->mps_state[-2*i-1]= 1;
143 c->mps_state[-2*i-2]= 0;
145 c->lps_state[2*i+0]= 2*lps_state[i]+0;
146 c->lps_state[2*i+1]= 2*lps_state[i]+1;
148 c->lps_state[2*i+0]= 1;
149 c->lps_state[2*i+1]= 0;
165 uint8_t state[10]= {0};
167 ff_init_cabac_encoder(&c, b, SIZE);
168 ff_init_cabac_states(&c, ff_h264_lps_range, ff_h264_mps_state, ff_h264_lps_state, 64);
170 for(i=0; i<SIZE; i++){
174 for(i=0; i<SIZE; i++){
176 put_cabac_bypass(&c, r[i]&1);
177 STOP_TIMER("put_cabac_bypass")
180 for(i=0; i<SIZE; i++){
182 put_cabac(&c, state, r[i]&1);
183 STOP_TIMER("put_cabac")
186 for(i=0; i<SIZE; i++){
188 put_cabac_u(&c, state, r[i], 6, 3, i&1);
189 STOP_TIMER("put_cabac_u")
192 for(i=0; i<SIZE; i++){
194 put_cabac_ueg(&c, state, r[i], 3, 0, 1, 2);
195 STOP_TIMER("put_cabac_ueg")
198 put_cabac_terminate(&c, 1);
200 ff_init_cabac_decoder(&c, b, SIZE);
202 memset(state, 0, sizeof(state));
204 for(i=0; i<SIZE; i++){
206 if( (r[i]&1) != get_cabac_bypass(&c) )
207 av_log(NULL, AV_LOG_ERROR, "CABAC bypass failure at %d\n", i);
208 STOP_TIMER("get_cabac_bypass")
211 for(i=0; i<SIZE; i++){
213 if( (r[i]&1) != get_cabac(&c, state) )
214 av_log(NULL, AV_LOG_ERROR, "CABAC failure at %d\n", i);
215 STOP_TIMER("get_cabac")
218 for(i=0; i<SIZE; i++){
220 if( r[i] != get_cabac_u(&c, state, (i&1) ? 6 : 7, 3, i&1) )
221 av_log(NULL, AV_LOG_ERROR, "CABAC unary (truncated) binarization failure at %d\n", i);
222 STOP_TIMER("get_cabac_u")
225 for(i=0; i<SIZE; i++){
227 if( r[i] != get_cabac_ueg(&c, state, 3, 0, 1, 2))
228 av_log(NULL, AV_LOG_ERROR, "CABAC unary (truncated) binarization failure at %d\n", i);
229 STOP_TIMER("get_cabac_ueg")
232 if(!get_cabac_terminate(&c))
233 av_log(NULL, AV_LOG_ERROR, "where's the Terminator?\n");