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#include <string.h> 28 29#include "libavutil/common.h" 30#include "get_bits.h" 31#include "cabac.h" 32 33static const uint8_t lps_range[64][4]= { 34{128,176,208,240}, {128,167,197,227}, {128,158,187,216}, {123,150,178,205}, 35{116,142,169,195}, {111,135,160,185}, {105,128,152,175}, {100,122,144,166}, 36{ 95,116,137,158}, { 90,110,130,150}, { 85,104,123,142}, { 81, 99,117,135}, 37{ 77, 94,111,128}, { 73, 89,105,122}, { 69, 85,100,116}, { 66, 80, 95,110}, 38{ 62, 76, 90,104}, { 59, 72, 86, 99}, { 56, 69, 81, 94}, { 53, 65, 77, 89}, 39{ 51, 62, 73, 85}, { 48, 59, 69, 80}, { 46, 56, 66, 76}, { 43, 53, 63, 72}, 40{ 41, 50, 59, 69}, { 39, 48, 56, 65}, { 37, 45, 54, 62}, { 35, 43, 51, 59}, 41{ 33, 41, 48, 56}, { 32, 39, 46, 53}, { 30, 37, 43, 50}, { 29, 35, 41, 48}, 42{ 27, 33, 39, 45}, { 26, 31, 37, 43}, { 24, 30, 35, 41}, { 23, 28, 33, 39}, 43{ 22, 27, 32, 37}, { 21, 26, 30, 35}, { 20, 24, 29, 33}, { 19, 23, 27, 31}, 44{ 18, 22, 26, 30}, { 17, 21, 25, 28}, { 16, 20, 23, 27}, { 15, 19, 22, 25}, 45{ 14, 18, 21, 24}, { 14, 17, 20, 23}, { 13, 16, 19, 22}, { 12, 15, 18, 21}, 46{ 12, 14, 17, 20}, { 11, 14, 16, 19}, { 11, 13, 15, 18}, { 10, 12, 15, 17}, 47{ 10, 12, 14, 16}, { 9, 11, 13, 15}, { 9, 11, 12, 14}, { 8, 10, 12, 14}, 48{ 8, 9, 11, 13}, { 7, 9, 11, 12}, { 7, 9, 10, 12}, { 7, 8, 10, 11}, 49{ 6, 8, 9, 11}, { 6, 7, 9, 10}, { 6, 7, 8, 9}, { 2, 2, 2, 2}, 50}; 51 52uint8_t ff_h264_mlps_state[4*64]; 53uint8_t ff_h264_lps_range[4*2*64]; 54uint8_t ff_h264_lps_state[2*64]; 55uint8_t ff_h264_mps_state[2*64]; 56 57static const uint8_t mps_state[64]= { 58 1, 2, 3, 4, 5, 6, 7, 8, 59 9,10,11,12,13,14,15,16, 60 17,18,19,20,21,22,23,24, 61 25,26,27,28,29,30,31,32, 62 33,34,35,36,37,38,39,40, 63 41,42,43,44,45,46,47,48, 64 49,50,51,52,53,54,55,56, 65 57,58,59,60,61,62,62,63, 66}; 67 68static const uint8_t lps_state[64]= { 69 0, 0, 1, 2, 2, 4, 4, 5, 70 6, 7, 8, 9, 9,11,11,12, 71 13,13,15,15,16,16,18,18, 72 19,19,21,21,22,22,23,24, 73 24,25,26,26,27,27,28,29, 74 29,30,30,30,31,32,32,33, 75 33,33,34,34,35,35,35,36, 76 36,36,37,37,37,38,38,63, 77}; 78#if 0 79const uint8_t ff_h264_norm_shift_old[128]= { 80 7,6,5,5,4,4,4,4,3,3,3,3,3,3,3,3, 81 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2, 82 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, 83 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, 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, 86 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 87 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 88}; 89#endif 90const uint8_t ff_h264_norm_shift[512]= { 91 9,8,7,7,6,6,6,6,5,5,5,5,5,5,5,5, 92 4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4, 93 3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3, 94 3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3, 95 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2, 96 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2, 97 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2, 98 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2, 99 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, 100 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, 101 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, 102 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, 103 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 104 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 105 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 106 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 107 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 108 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 109 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 110 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 111}; 112 113/** 114 * 115 * @param buf_size size of buf in bits 116 */ 117void ff_init_cabac_encoder(CABACContext *c, uint8_t *buf, int buf_size){ 118 init_put_bits(&c->pb, buf, buf_size); 119 120 c->low= 0; 121 c->range= 0x1FE; 122 c->outstanding_count= 0; 123#ifdef STRICT_LIMITS 124 c->sym_count =0; 125#endif 126 127 c->pb.bit_left++; //avoids firstBitFlag 128} 129 130/** 131 * 132 * @param buf_size size of buf in bits 133 */ 134void ff_init_cabac_decoder(CABACContext *c, const uint8_t *buf, int buf_size){ 135 c->bytestream_start= 136 c->bytestream= buf; 137 c->bytestream_end= buf + buf_size; 138 139#if CABAC_BITS == 16 140 c->low = (*c->bytestream++)<<18; 141 c->low+= (*c->bytestream++)<<10; 142#else 143 c->low = (*c->bytestream++)<<10; 144#endif 145 c->low+= ((*c->bytestream++)<<2) + 2; 146 c->range= 0x1FE; 147} 148 149void ff_init_cabac_states(CABACContext *c){ 150 int i, j; 151 152 for(i=0; i<64; i++){ 153 for(j=0; j<4; j++){ //FIXME check if this is worth the 1 shift we save 154 ff_h264_lps_range[j*2*64+2*i+0]= 155 ff_h264_lps_range[j*2*64+2*i+1]= lps_range[i][j]; 156 } 157 158 ff_h264_mlps_state[128+2*i+0]= 159 ff_h264_mps_state[2*i+0]= 2*mps_state[i]+0; 160 ff_h264_mlps_state[128+2*i+1]= 161 ff_h264_mps_state[2*i+1]= 2*mps_state[i]+1; 162 163 if( i ){ 164#ifdef BRANCHLESS_CABAC_DECODER 165 ff_h264_mlps_state[128-2*i-1]= 2*lps_state[i]+0; 166 ff_h264_mlps_state[128-2*i-2]= 2*lps_state[i]+1; 167 }else{ 168 ff_h264_mlps_state[128-2*i-1]= 1; 169 ff_h264_mlps_state[128-2*i-2]= 0; 170#else 171 ff_h264_lps_state[2*i+0]= 2*lps_state[i]+0; 172 ff_h264_lps_state[2*i+1]= 2*lps_state[i]+1; 173 }else{ 174 ff_h264_lps_state[2*i+0]= 1; 175 ff_h264_lps_state[2*i+1]= 0; 176#endif 177 } 178 } 179} 180 181#ifdef TEST 182#define SIZE 10240 183 184#include "libavutil/lfg.h" 185#include "avcodec.h" 186#include "cabac.h" 187 188int main(void){ 189 CABACContext c; 190 uint8_t b[9*SIZE]; 191 uint8_t r[9*SIZE]; 192 int i; 193 uint8_t state[10]= {0}; 194 AVLFG prng; 195 196 av_lfg_init(&prng, 1); 197 ff_init_cabac_encoder(&c, b, SIZE); 198 ff_init_cabac_states(&c); 199 200 for(i=0; i<SIZE; i++){ 201 r[i] = av_lfg_get(&prng) % 7; 202 } 203 204 for(i=0; i<SIZE; i++){ 205START_TIMER 206 put_cabac_bypass(&c, r[i]&1); 207STOP_TIMER("put_cabac_bypass") 208 } 209 210 for(i=0; i<SIZE; i++){ 211START_TIMER 212 put_cabac(&c, state, r[i]&1); 213STOP_TIMER("put_cabac") 214 } 215 216 for(i=0; i<SIZE; i++){ 217START_TIMER 218 put_cabac_u(&c, state, r[i], 6, 3, i&1); 219STOP_TIMER("put_cabac_u") 220 } 221 222 for(i=0; i<SIZE; i++){ 223START_TIMER 224 put_cabac_ueg(&c, state, r[i], 3, 0, 1, 2); 225STOP_TIMER("put_cabac_ueg") 226 } 227 228 put_cabac_terminate(&c, 1); 229 230 ff_init_cabac_decoder(&c, b, SIZE); 231 232 memset(state, 0, sizeof(state)); 233 234 for(i=0; i<SIZE; i++){ 235START_TIMER 236 if( (r[i]&1) != get_cabac_bypass(&c) ) 237 av_log(NULL, AV_LOG_ERROR, "CABAC bypass failure at %d\n", i); 238STOP_TIMER("get_cabac_bypass") 239 } 240 241 for(i=0; i<SIZE; i++){ 242START_TIMER 243 if( (r[i]&1) != get_cabac(&c, state) ) 244 av_log(NULL, AV_LOG_ERROR, "CABAC failure at %d\n", i); 245STOP_TIMER("get_cabac") 246 } 247#if 0 248 for(i=0; i<SIZE; i++){ 249START_TIMER 250 if( r[i] != get_cabac_u(&c, state, (i&1) ? 6 : 7, 3, i&1) ) 251 av_log(NULL, AV_LOG_ERROR, "CABAC unary (truncated) binarization failure at %d\n", i); 252STOP_TIMER("get_cabac_u") 253 } 254 255 for(i=0; i<SIZE; i++){ 256START_TIMER 257 if( r[i] != get_cabac_ueg(&c, state, 3, 0, 1, 2)) 258 av_log(NULL, AV_LOG_ERROR, "CABAC unary (truncated) binarization failure at %d\n", i); 259STOP_TIMER("get_cabac_ueg") 260 } 261#endif 262 if(!get_cabac_terminate(&c)) 263 av_log(NULL, AV_LOG_ERROR, "where's the Terminator?\n"); 264 265 return 0; 266} 267 268#endif /* TEST */ 269