annotate libavcodec/cabac.c @ 3:0b056460c67d

changed code to use VSs
author Nina Engelhardt <nengel@mailbox.tu-berlin.de>
date Mon, 29 Oct 2012 16:44:27 +0100
parents
children
rev   line source
nengel@2 1 /*
nengel@2 2 * H.26L/H.264/AVC/JVT/14496-10/... encoder/decoder
nengel@2 3 * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
nengel@2 4 *
nengel@2 5 * This file is part of FFmpeg.
nengel@2 6 *
nengel@2 7 * FFmpeg is free software; you can redistribute it and/or
nengel@2 8 * modify it under the terms of the GNU Lesser General Public
nengel@2 9 * License as published by the Free Software Foundation; either
nengel@2 10 * version 2.1 of the License, or (at your option) any later version.
nengel@2 11 *
nengel@2 12 * FFmpeg is distributed in the hope that it will be useful,
nengel@2 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
nengel@2 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
nengel@2 15 * Lesser General Public License for more details.
nengel@2 16 *
nengel@2 17 * You should have received a copy of the GNU Lesser General Public
nengel@2 18 * License along with FFmpeg; if not, write to the Free Software
nengel@2 19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
nengel@2 20 */
nengel@2 21
nengel@2 22 /**
nengel@2 23 * @file
nengel@2 24 * Context Adaptive Binary Arithmetic Coder.
nengel@2 25 */
nengel@2 26
nengel@2 27 #include <string.h>
nengel@2 28
nengel@2 29 #include "libavutil/common.h"
nengel@2 30 //#include "get_bits.h"
nengel@2 31 #include "cabac.h"
nengel@2 32
nengel@2 33 static const uint8_t lps_range[64][4]= {
nengel@2 34 {128,176,208,240}, {128,167,197,227}, {128,158,187,216}, {123,150,178,205},
nengel@2 35 {116,142,169,195}, {111,135,160,185}, {105,128,152,175}, {100,122,144,166},
nengel@2 36 { 95,116,137,158}, { 90,110,130,150}, { 85,104,123,142}, { 81, 99,117,135},
nengel@2 37 { 77, 94,111,128}, { 73, 89,105,122}, { 69, 85,100,116}, { 66, 80, 95,110},
nengel@2 38 { 62, 76, 90,104}, { 59, 72, 86, 99}, { 56, 69, 81, 94}, { 53, 65, 77, 89},
nengel@2 39 { 51, 62, 73, 85}, { 48, 59, 69, 80}, { 46, 56, 66, 76}, { 43, 53, 63, 72},
nengel@2 40 { 41, 50, 59, 69}, { 39, 48, 56, 65}, { 37, 45, 54, 62}, { 35, 43, 51, 59},
nengel@2 41 { 33, 41, 48, 56}, { 32, 39, 46, 53}, { 30, 37, 43, 50}, { 29, 35, 41, 48},
nengel@2 42 { 27, 33, 39, 45}, { 26, 31, 37, 43}, { 24, 30, 35, 41}, { 23, 28, 33, 39},
nengel@2 43 { 22, 27, 32, 37}, { 21, 26, 30, 35}, { 20, 24, 29, 33}, { 19, 23, 27, 31},
nengel@2 44 { 18, 22, 26, 30}, { 17, 21, 25, 28}, { 16, 20, 23, 27}, { 15, 19, 22, 25},
nengel@2 45 { 14, 18, 21, 24}, { 14, 17, 20, 23}, { 13, 16, 19, 22}, { 12, 15, 18, 21},
nengel@2 46 { 12, 14, 17, 20}, { 11, 14, 16, 19}, { 11, 13, 15, 18}, { 10, 12, 15, 17},
nengel@2 47 { 10, 12, 14, 16}, { 9, 11, 13, 15}, { 9, 11, 12, 14}, { 8, 10, 12, 14},
nengel@2 48 { 8, 9, 11, 13}, { 7, 9, 11, 12}, { 7, 9, 10, 12}, { 7, 8, 10, 11},
nengel@2 49 { 6, 8, 9, 11}, { 6, 7, 9, 10}, { 6, 7, 8, 9}, { 2, 2, 2, 2},
nengel@2 50 };
nengel@2 51
nengel@2 52 uint8_t ff_h264_mlps_state[4*64];
nengel@2 53 uint8_t ff_h264_lps_range[4*2*64];
nengel@2 54 uint8_t ff_h264_lps_state[2*64];
nengel@2 55 uint8_t ff_h264_mps_state[2*64];
nengel@2 56
nengel@2 57 static const uint8_t mps_state[64]= {
nengel@2 58 1, 2, 3, 4, 5, 6, 7, 8,
nengel@2 59 9,10,11,12,13,14,15,16,
nengel@2 60 17,18,19,20,21,22,23,24,
nengel@2 61 25,26,27,28,29,30,31,32,
nengel@2 62 33,34,35,36,37,38,39,40,
nengel@2 63 41,42,43,44,45,46,47,48,
nengel@2 64 49,50,51,52,53,54,55,56,
nengel@2 65 57,58,59,60,61,62,62,63,
nengel@2 66 };
nengel@2 67
nengel@2 68 static const uint8_t lps_state[64]= {
nengel@2 69 0, 0, 1, 2, 2, 4, 4, 5,
nengel@2 70 6, 7, 8, 9, 9,11,11,12,
nengel@2 71 13,13,15,15,16,16,18,18,
nengel@2 72 19,19,21,21,22,22,23,24,
nengel@2 73 24,25,26,26,27,27,28,29,
nengel@2 74 29,30,30,30,31,32,32,33,
nengel@2 75 33,33,34,34,35,35,35,36,
nengel@2 76 36,36,37,37,37,38,38,63,
nengel@2 77 };
nengel@2 78
nengel@2 79 const uint8_t ff_h264_norm_shift[512]= {
nengel@2 80 9,8,7,7,6,6,6,6,5,5,5,5,5,5,5,5,
nengel@2 81 4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,
nengel@2 82 3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,
nengel@2 83 3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,
nengel@2 84 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
nengel@2 85 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
nengel@2 86 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
nengel@2 87 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
nengel@2 88 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,
nengel@2 89 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,
nengel@2 90 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,
nengel@2 91 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,
nengel@2 92 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
nengel@2 93 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
nengel@2 94 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
nengel@2 95 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
nengel@2 96 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
nengel@2 97 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
nengel@2 98 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
nengel@2 99 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
nengel@2 100 };
nengel@2 101
nengel@2 102 /**
nengel@2 103 *
nengel@2 104 * @param buf_size size of buf in bits
nengel@2 105 */
nengel@2 106 void ff_init_cabac_decoder(CABACContext *c, const uint8_t *buf, int buf_size){
nengel@2 107 c->bytestream_start=
nengel@2 108 c->bytestream= buf;
nengel@2 109 c->bytestream_end= buf + buf_size;
nengel@2 110
nengel@2 111 #if CABAC_BITS == 16
nengel@2 112 c->low = (*c->bytestream++)<<18;
nengel@2 113 c->low+= (*c->bytestream++)<<10;
nengel@2 114 #else
nengel@2 115 c->low = (*c->bytestream++)<<10;
nengel@2 116 #endif
nengel@2 117 c->low+= ((*c->bytestream++)<<2) + 2;
nengel@2 118 c->range= 0x1FE;
nengel@2 119 }
nengel@2 120
nengel@2 121 void ff_init_cabac_states(){
nengel@2 122 int i, j;
nengel@2 123
nengel@2 124 for(i=0; i<64; i++){
nengel@2 125 for(j=0; j<4; j++){ //FIXME check if this is worth the 1 shift we save
nengel@2 126 ff_h264_lps_range[j*2*64+2*i+0]=
nengel@2 127 ff_h264_lps_range[j*2*64+2*i+1]= lps_range[i][j];
nengel@2 128 }
nengel@2 129
nengel@2 130 ff_h264_mlps_state[128+2*i+0]=
nengel@2 131 ff_h264_mps_state[2*i+0]= 2*mps_state[i]+0;
nengel@2 132 ff_h264_mlps_state[128+2*i+1]=
nengel@2 133 ff_h264_mps_state[2*i+1]= 2*mps_state[i]+1;
nengel@2 134
nengel@2 135 if( i ){
nengel@2 136 #ifdef BRANCHLESS_CABAC_DECODER
nengel@2 137 ff_h264_mlps_state[128-2*i-1]= 2*lps_state[i]+0;
nengel@2 138 ff_h264_mlps_state[128-2*i-2]= 2*lps_state[i]+1;
nengel@2 139 }else{
nengel@2 140 ff_h264_mlps_state[128-2*i-1]= 1;
nengel@2 141 ff_h264_mlps_state[128-2*i-2]= 0;
nengel@2 142 #else
nengel@2 143 ff_h264_lps_state[2*i+0]= 2*lps_state[i]+0;
nengel@2 144 ff_h264_lps_state[2*i+1]= 2*lps_state[i]+1;
nengel@2 145 }else{
nengel@2 146 ff_h264_lps_state[2*i+0]= 1;
nengel@2 147 ff_h264_lps_state[2*i+1]= 0;
nengel@2 148 #endif
nengel@2 149 }
nengel@2 150 }
nengel@2 151 }
nengel@2 152
nengel@2 153 #ifdef TEST
nengel@2 154 #define SIZE 10240
nengel@2 155 #define START_TIMER
nengel@2 156 #define STOP_TIMER(...)
nengel@2 157 #define av_log(...)
nengel@2 158 // #include "libavutil/lfg.h"
nengel@2 159 #include "avcodec.h"
nengel@2 160 #include "cabac.h"
nengel@2 161
nengel@2 162 int main(void){
nengel@2 163 CABACContext c;
nengel@2 164 uint8_t b[9*SIZE];
nengel@2 165 uint8_t r[9*SIZE];
nengel@2 166 int i;
nengel@2 167 uint8_t state[10]= {0};
nengel@2 168 // AVLFG prng;
nengel@2 169
nengel@2 170 // // av_lfg_init(&prng, 1);
nengel@2 171 // ff_init_cabac_encoder(&c, b, SIZE);
nengel@2 172 // ff_init_cabac_states();
nengel@2 173 //
nengel@2 174 // for(i=0; i<SIZE; i++){
nengel@2 175 // r[i] = i%7; //av_lfg_get(&prng) % 7;
nengel@2 176 // }
nengel@2 177 //
nengel@2 178 // for(i=0; i<SIZE; i++){
nengel@2 179 // START_TIMER
nengel@2 180 // put_cabac_bypass(&c, r[i]&1);
nengel@2 181 // STOP_TIMER("put_cabac_bypass")
nengel@2 182 // }
nengel@2 183 //
nengel@2 184 // for(i=0; i<SIZE; i++){
nengel@2 185 // START_TIMER
nengel@2 186 // put_cabac(&c, state, r[i]&1);
nengel@2 187 // STOP_TIMER("put_cabac")
nengel@2 188 // }
nengel@2 189 //
nengel@2 190 // for(i=0; i<SIZE; i++){
nengel@2 191 // START_TIMER
nengel@2 192 // put_cabac_u(&c, state, r[i], 6, 3, i&1);
nengel@2 193 // STOP_TIMER("put_cabac_u")
nengel@2 194 // }
nengel@2 195 //
nengel@2 196 // for(i=0; i<SIZE; i++){
nengel@2 197 // START_TIMER
nengel@2 198 // put_cabac_ueg(&c, state, r[i], 3, 0, 1, 2);
nengel@2 199 // STOP_TIMER("put_cabac_ueg")
nengel@2 200 // }
nengel@2 201 //
nengel@2 202 // put_cabac_terminate(&c, 1);
nengel@2 203
nengel@2 204 ff_init_cabac_decoder(&c, b, SIZE);
nengel@2 205
nengel@2 206 memset(state, 0, sizeof(state));
nengel@2 207
nengel@2 208 for(i=0; i<SIZE; i++){
nengel@2 209 START_TIMER
nengel@2 210 if( (r[i]&1) != get_cabac_bypass(&c) )
nengel@2 211 av_log(NULL, AV_LOG_ERROR, "CABAC bypass failure at %d\n", i);
nengel@2 212 STOP_TIMER("get_cabac_bypass")
nengel@2 213 }
nengel@2 214
nengel@2 215 for(i=0; i<SIZE; i++){
nengel@2 216 START_TIMER
nengel@2 217 if( (r[i]&1) != get_cabac(&c, state) )
nengel@2 218 av_log(NULL, AV_LOG_ERROR, "CABAC failure at %d\n", i);
nengel@2 219 STOP_TIMER("get_cabac")
nengel@2 220 }
nengel@2 221 #if 0
nengel@2 222 for(i=0; i<SIZE; i++){
nengel@2 223 START_TIMER
nengel@2 224 if( r[i] != get_cabac_u(&c, state, (i&1) ? 6 : 7, 3, i&1) )
nengel@2 225 av_log(NULL, AV_LOG_ERROR, "CABAC unary (truncated) binarization failure at %d\n", i);
nengel@2 226 STOP_TIMER("get_cabac_u")
nengel@2 227 }
nengel@2 228
nengel@2 229 for(i=0; i<SIZE; i++){
nengel@2 230 START_TIMER
nengel@2 231 if( r[i] != get_cabac_ueg(&c, state, 3, 0, 1, 2))
nengel@2 232 av_log(NULL, AV_LOG_ERROR, "CABAC unary (truncated) binarization failure at %d\n", i);
nengel@2 233 STOP_TIMER("get_cabac_ueg")
nengel@2 234 }
nengel@2 235 #endif
nengel@2 236 if(!get_cabac_terminate(&c))
nengel@2 237 av_log(NULL, AV_LOG_ERROR, "where's the Terminator?\n");
nengel@2 238
nengel@2 239 return 0;
nengel@2 240 }
nengel@2 241
nengel@2 242 #endif /* TEST */