nengel@2: /*
nengel@2:  * H.26L/H.264/AVC/JVT/14496-10/... encoder/decoder
nengel@2:  * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
nengel@2:  *
nengel@2:  * This file is part of FFmpeg.
nengel@2:  *
nengel@2:  * FFmpeg is free software; you can redistribute it and/or
nengel@2:  * modify it under the terms of the GNU Lesser General Public
nengel@2:  * License as published by the Free Software Foundation; either
nengel@2:  * version 2.1 of the License, or (at your option) any later version.
nengel@2:  *
nengel@2:  * FFmpeg is distributed in the hope that it will be useful,
nengel@2:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
nengel@2:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
nengel@2:  * Lesser General Public License for more details.
nengel@2:  *
nengel@2:  * You should have received a copy of the GNU Lesser General Public
nengel@2:  * License along with FFmpeg; if not, write to the Free Software
nengel@2:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
nengel@2:  */
nengel@2: 
nengel@2: /**
nengel@2:  * @file
nengel@2:  * Context Adaptive Binary Arithmetic Coder.
nengel@2:  */
nengel@2: 
nengel@2: #include <string.h>
nengel@2: 
nengel@2: #include "libavutil/common.h"
nengel@2: //#include "get_bits.h"
nengel@2: #include "cabac.h"
nengel@2: 
nengel@2: static const uint8_t lps_range[64][4]= {
nengel@2: {128,176,208,240}, {128,167,197,227}, {128,158,187,216}, {123,150,178,205},
nengel@2: {116,142,169,195}, {111,135,160,185}, {105,128,152,175}, {100,122,144,166},
nengel@2: { 95,116,137,158}, { 90,110,130,150}, { 85,104,123,142}, { 81, 99,117,135},
nengel@2: { 77, 94,111,128}, { 73, 89,105,122}, { 69, 85,100,116}, { 66, 80, 95,110},
nengel@2: { 62, 76, 90,104}, { 59, 72, 86, 99}, { 56, 69, 81, 94}, { 53, 65, 77, 89},
nengel@2: { 51, 62, 73, 85}, { 48, 59, 69, 80}, { 46, 56, 66, 76}, { 43, 53, 63, 72},
nengel@2: { 41, 50, 59, 69}, { 39, 48, 56, 65}, { 37, 45, 54, 62}, { 35, 43, 51, 59},
nengel@2: { 33, 41, 48, 56}, { 32, 39, 46, 53}, { 30, 37, 43, 50}, { 29, 35, 41, 48},
nengel@2: { 27, 33, 39, 45}, { 26, 31, 37, 43}, { 24, 30, 35, 41}, { 23, 28, 33, 39},
nengel@2: { 22, 27, 32, 37}, { 21, 26, 30, 35}, { 20, 24, 29, 33}, { 19, 23, 27, 31},
nengel@2: { 18, 22, 26, 30}, { 17, 21, 25, 28}, { 16, 20, 23, 27}, { 15, 19, 22, 25},
nengel@2: { 14, 18, 21, 24}, { 14, 17, 20, 23}, { 13, 16, 19, 22}, { 12, 15, 18, 21},
nengel@2: { 12, 14, 17, 20}, { 11, 14, 16, 19}, { 11, 13, 15, 18}, { 10, 12, 15, 17},
nengel@2: { 10, 12, 14, 16}, {  9, 11, 13, 15}, {  9, 11, 12, 14}, {  8, 10, 12, 14},
nengel@2: {  8,  9, 11, 13}, {  7,  9, 11, 12}, {  7,  9, 10, 12}, {  7,  8, 10, 11},
nengel@2: {  6,  8,  9, 11}, {  6,  7,  9, 10}, {  6,  7,  8,  9}, {  2,  2,  2,  2},
nengel@2: };
nengel@2: 
nengel@2: uint8_t ff_h264_mlps_state[4*64];
nengel@2: uint8_t ff_h264_lps_range[4*2*64];
nengel@2: uint8_t ff_h264_lps_state[2*64];
nengel@2: uint8_t ff_h264_mps_state[2*64];
nengel@2: 
nengel@2: static const uint8_t mps_state[64]= {
nengel@2:   1, 2, 3, 4, 5, 6, 7, 8,
nengel@2:   9,10,11,12,13,14,15,16,
nengel@2:  17,18,19,20,21,22,23,24,
nengel@2:  25,26,27,28,29,30,31,32,
nengel@2:  33,34,35,36,37,38,39,40,
nengel@2:  41,42,43,44,45,46,47,48,
nengel@2:  49,50,51,52,53,54,55,56,
nengel@2:  57,58,59,60,61,62,62,63,
nengel@2: };
nengel@2: 
nengel@2: static const uint8_t lps_state[64]= {
nengel@2:   0, 0, 1, 2, 2, 4, 4, 5,
nengel@2:   6, 7, 8, 9, 9,11,11,12,
nengel@2:  13,13,15,15,16,16,18,18,
nengel@2:  19,19,21,21,22,22,23,24,
nengel@2:  24,25,26,26,27,27,28,29,
nengel@2:  29,30,30,30,31,32,32,33,
nengel@2:  33,33,34,34,35,35,35,36,
nengel@2:  36,36,37,37,37,38,38,63,
nengel@2: };
nengel@2: 
nengel@2: const uint8_t ff_h264_norm_shift[512]= {
nengel@2:  9,8,7,7,6,6,6,6,5,5,5,5,5,5,5,5,
nengel@2:  4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,
nengel@2:  3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,
nengel@2:  3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,
nengel@2:  2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
nengel@2:  2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
nengel@2:  2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
nengel@2:  2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
nengel@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,
nengel@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,
nengel@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,
nengel@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,
nengel@2:  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
nengel@2:  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
nengel@2:  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
nengel@2:  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
nengel@2:  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
nengel@2:  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
nengel@2:  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
nengel@2:  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
nengel@2: };
nengel@2: 
nengel@2: /**
nengel@2:  *
nengel@2:  * @param buf_size size of buf in bits
nengel@2:  */
nengel@2: void ff_init_cabac_decoder(CABACContext *c, const uint8_t *buf, int buf_size){
nengel@2:     c->bytestream_start=
nengel@2:     c->bytestream= buf;
nengel@2:     c->bytestream_end= buf + buf_size;
nengel@2: 
nengel@2: #if CABAC_BITS == 16
nengel@2:     c->low =  (*c->bytestream++)<<18;
nengel@2:     c->low+=  (*c->bytestream++)<<10;
nengel@2: #else
nengel@2:     c->low =  (*c->bytestream++)<<10;
nengel@2: #endif
nengel@2:     c->low+= ((*c->bytestream++)<<2) + 2;
nengel@2:     c->range= 0x1FE;
nengel@2: }
nengel@2: 
nengel@2: void ff_init_cabac_states(){
nengel@2:     int i, j;
nengel@2: 
nengel@2:     for(i=0; i<64; i++){
nengel@2:         for(j=0; j<4; j++){ //FIXME check if this is worth the 1 shift we save
nengel@2:             ff_h264_lps_range[j*2*64+2*i+0]=
nengel@2:             ff_h264_lps_range[j*2*64+2*i+1]= lps_range[i][j];
nengel@2:         }
nengel@2: 
nengel@2:         ff_h264_mlps_state[128+2*i+0]=
nengel@2:         ff_h264_mps_state[2*i+0]= 2*mps_state[i]+0;
nengel@2:         ff_h264_mlps_state[128+2*i+1]=
nengel@2:         ff_h264_mps_state[2*i+1]= 2*mps_state[i]+1;
nengel@2: 
nengel@2:         if( i ){
nengel@2: #ifdef BRANCHLESS_CABAC_DECODER
nengel@2:             ff_h264_mlps_state[128-2*i-1]= 2*lps_state[i]+0;
nengel@2:             ff_h264_mlps_state[128-2*i-2]= 2*lps_state[i]+1;
nengel@2:         }else{
nengel@2:             ff_h264_mlps_state[128-2*i-1]= 1;
nengel@2:             ff_h264_mlps_state[128-2*i-2]= 0;
nengel@2: #else
nengel@2:             ff_h264_lps_state[2*i+0]= 2*lps_state[i]+0;
nengel@2:             ff_h264_lps_state[2*i+1]= 2*lps_state[i]+1;
nengel@2:         }else{
nengel@2:             ff_h264_lps_state[2*i+0]= 1;
nengel@2:             ff_h264_lps_state[2*i+1]= 0;
nengel@2: #endif
nengel@2:         }
nengel@2:     }
nengel@2: }
nengel@2: 
nengel@2: #ifdef TEST
nengel@2: #define SIZE 10240
nengel@2: #define START_TIMER
nengel@2: #define STOP_TIMER(...)
nengel@2: #define av_log(...)
nengel@2: // #include "libavutil/lfg.h"
nengel@2: #include "avcodec.h"
nengel@2: #include "cabac.h"
nengel@2: 
nengel@2: int main(void){
nengel@2:     CABACContext c;
nengel@2:     uint8_t b[9*SIZE];
nengel@2:     uint8_t r[9*SIZE];
nengel@2:     int i;
nengel@2:     uint8_t state[10]= {0};
nengel@2: //    AVLFG prng;
nengel@2: 
nengel@2: // //     av_lfg_init(&prng, 1);
nengel@2: //     ff_init_cabac_encoder(&c, b, SIZE);
nengel@2: //     ff_init_cabac_states();
nengel@2: //
nengel@2: //     for(i=0; i<SIZE; i++){
nengel@2: //         r[i] = i%7; //av_lfg_get(&prng) % 7;
nengel@2: //     }
nengel@2: //
nengel@2: //     for(i=0; i<SIZE; i++){
nengel@2: // START_TIMER
nengel@2: //         put_cabac_bypass(&c, r[i]&1);
nengel@2: // STOP_TIMER("put_cabac_bypass")
nengel@2: //     }
nengel@2: //
nengel@2: //     for(i=0; i<SIZE; i++){
nengel@2: // START_TIMER
nengel@2: //         put_cabac(&c, state, r[i]&1);
nengel@2: // STOP_TIMER("put_cabac")
nengel@2: //     }
nengel@2: //
nengel@2: //     for(i=0; i<SIZE; i++){
nengel@2: // START_TIMER
nengel@2: //         put_cabac_u(&c, state, r[i], 6, 3, i&1);
nengel@2: // STOP_TIMER("put_cabac_u")
nengel@2: //     }
nengel@2: //
nengel@2: //     for(i=0; i<SIZE; i++){
nengel@2: // START_TIMER
nengel@2: //         put_cabac_ueg(&c, state, r[i], 3, 0, 1, 2);
nengel@2: // STOP_TIMER("put_cabac_ueg")
nengel@2: //     }
nengel@2: //
nengel@2: //     put_cabac_terminate(&c, 1);
nengel@2: 
nengel@2:     ff_init_cabac_decoder(&c, b, SIZE);
nengel@2: 
nengel@2:     memset(state, 0, sizeof(state));
nengel@2: 
nengel@2:     for(i=0; i<SIZE; i++){
nengel@2: START_TIMER
nengel@2:         if( (r[i]&1) != get_cabac_bypass(&c) )
nengel@2:             av_log(NULL, AV_LOG_ERROR, "CABAC bypass failure at %d\n", i);
nengel@2: STOP_TIMER("get_cabac_bypass")
nengel@2:     }
nengel@2: 
nengel@2:     for(i=0; i<SIZE; i++){
nengel@2: START_TIMER
nengel@2:         if( (r[i]&1) != get_cabac(&c, state) )
nengel@2:             av_log(NULL, AV_LOG_ERROR, "CABAC failure at %d\n", i);
nengel@2: STOP_TIMER("get_cabac")
nengel@2:     }
nengel@2: #if 0
nengel@2:     for(i=0; i<SIZE; i++){
nengel@2: START_TIMER
nengel@2:         if( r[i] != get_cabac_u(&c, state, (i&1) ? 6 : 7, 3, i&1) )
nengel@2:             av_log(NULL, AV_LOG_ERROR, "CABAC unary (truncated) binarization failure at %d\n", i);
nengel@2: STOP_TIMER("get_cabac_u")
nengel@2:     }
nengel@2: 
nengel@2:     for(i=0; i<SIZE; i++){
nengel@2: START_TIMER
nengel@2:         if( r[i] != get_cabac_ueg(&c, state, 3, 0, 1, 2))
nengel@2:             av_log(NULL, AV_LOG_ERROR, "CABAC unary (truncated) binarization failure at %d\n", i);
nengel@2: STOP_TIMER("get_cabac_ueg")
nengel@2:     }
nengel@2: #endif
nengel@2:     if(!get_cabac_terminate(&c))
nengel@2:         av_log(NULL, AV_LOG_ERROR, "where's the Terminator?\n");
nengel@2: 
nengel@2:     return 0;
nengel@2: }
nengel@2: 
nengel@2: #endif /* TEST */