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315 lines
8.8 KiB
315 lines
8.8 KiB
/* |
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* H.26L/H.264/AVC/JVT/14496-10/... encoder/decoder |
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* Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at> |
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* |
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* This file is part of FFmpeg. |
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* |
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* FFmpeg is free software; you can redistribute it and/or |
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* modify it under the terms of the GNU Lesser General Public |
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* License as published by the Free Software Foundation; either |
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* version 2.1 of the License, or (at your option) any later version. |
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* |
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* FFmpeg is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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* Lesser General Public License for more details. |
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* |
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* You should have received a copy of the GNU Lesser General Public |
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* License along with FFmpeg; if not, write to the Free Software |
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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*/ |
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/** |
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* @file |
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* Context Adaptive Binary Arithmetic Coder. |
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*/ |
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#include <string.h> |
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#include "libavutil/common.h" |
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#include "libavutil/timer.h" |
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#include "get_bits.h" |
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#include "cabac.h" |
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#include "cabac_functions.h" |
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uint8_t ff_h264_cabac_tables[512 + 4*2*64 + 4*64 + 63] = { |
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9,8,7,7,6,6,6,6,5,5,5,5,5,5,5,5, |
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4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4, |
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3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3, |
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3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3, |
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2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2, |
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2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2, |
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2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2, |
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2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2, |
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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, |
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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, |
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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, |
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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, |
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0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, |
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0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, |
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0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, |
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0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, |
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0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, |
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0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, |
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0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, |
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0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, |
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}; |
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static const uint8_t lps_range[64][4]= { |
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{128,176,208,240}, {128,167,197,227}, {128,158,187,216}, {123,150,178,205}, |
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{116,142,169,195}, {111,135,160,185}, {105,128,152,175}, {100,122,144,166}, |
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{ 95,116,137,158}, { 90,110,130,150}, { 85,104,123,142}, { 81, 99,117,135}, |
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{ 77, 94,111,128}, { 73, 89,105,122}, { 69, 85,100,116}, { 66, 80, 95,110}, |
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{ 62, 76, 90,104}, { 59, 72, 86, 99}, { 56, 69, 81, 94}, { 53, 65, 77, 89}, |
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{ 51, 62, 73, 85}, { 48, 59, 69, 80}, { 46, 56, 66, 76}, { 43, 53, 63, 72}, |
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{ 41, 50, 59, 69}, { 39, 48, 56, 65}, { 37, 45, 54, 62}, { 35, 43, 51, 59}, |
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{ 33, 41, 48, 56}, { 32, 39, 46, 53}, { 30, 37, 43, 50}, { 29, 35, 41, 48}, |
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{ 27, 33, 39, 45}, { 26, 31, 37, 43}, { 24, 30, 35, 41}, { 23, 28, 33, 39}, |
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{ 22, 27, 32, 37}, { 21, 26, 30, 35}, { 20, 24, 29, 33}, { 19, 23, 27, 31}, |
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{ 18, 22, 26, 30}, { 17, 21, 25, 28}, { 16, 20, 23, 27}, { 15, 19, 22, 25}, |
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{ 14, 18, 21, 24}, { 14, 17, 20, 23}, { 13, 16, 19, 22}, { 12, 15, 18, 21}, |
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{ 12, 14, 17, 20}, { 11, 14, 16, 19}, { 11, 13, 15, 18}, { 10, 12, 15, 17}, |
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{ 10, 12, 14, 16}, { 9, 11, 13, 15}, { 9, 11, 12, 14}, { 8, 10, 12, 14}, |
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{ 8, 9, 11, 13}, { 7, 9, 11, 12}, { 7, 9, 10, 12}, { 7, 8, 10, 11}, |
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{ 6, 8, 9, 11}, { 6, 7, 9, 10}, { 6, 7, 8, 9}, { 2, 2, 2, 2}, |
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}; |
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static const uint8_t mps_state[64]= { |
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1, 2, 3, 4, 5, 6, 7, 8, |
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9,10,11,12,13,14,15,16, |
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17,18,19,20,21,22,23,24, |
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25,26,27,28,29,30,31,32, |
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33,34,35,36,37,38,39,40, |
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41,42,43,44,45,46,47,48, |
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49,50,51,52,53,54,55,56, |
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57,58,59,60,61,62,62,63, |
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}; |
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static const uint8_t lps_state[64]= { |
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0, 0, 1, 2, 2, 4, 4, 5, |
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6, 7, 8, 9, 9,11,11,12, |
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13,13,15,15,16,16,18,18, |
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19,19,21,21,22,22,23,24, |
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24,25,26,26,27,27,28,29, |
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29,30,30,30,31,32,32,33, |
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33,33,34,34,35,35,35,36, |
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36,36,37,37,37,38,38,63, |
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}; |
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static const uint8_t last_coeff_flag_offset_8x8[63] = { |
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0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, |
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2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, |
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3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, |
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5, 5, 5, 5, 6, 6, 6, 6, 7, 7, 7, 7, 8, 8, 8 |
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}; |
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/** |
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* |
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* @param buf_size size of buf in bits |
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*/ |
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void ff_init_cabac_encoder(CABACContext *c, uint8_t *buf, int buf_size){ |
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init_put_bits(&c->pb, buf, buf_size); |
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c->low= 0; |
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c->range= 0x1FE; |
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c->outstanding_count= 0; |
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c->pb.bit_left++; //avoids firstBitFlag |
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} |
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/** |
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* |
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* @param buf_size size of buf in bits |
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*/ |
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void ff_init_cabac_decoder(CABACContext *c, const uint8_t *buf, int buf_size){ |
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c->bytestream_start= |
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c->bytestream= buf; |
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c->bytestream_end= buf + buf_size; |
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#if CABAC_BITS == 16 |
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c->low = (*c->bytestream++)<<18; |
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c->low+= (*c->bytestream++)<<10; |
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#else |
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c->low = (*c->bytestream++)<<10; |
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#endif |
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c->low+= ((*c->bytestream++)<<2) + 2; |
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c->range= 0x1FE; |
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} |
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void ff_init_cabac_states(void) |
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{ |
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int i, j; |
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static int initialized = 0; |
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if (initialized) |
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return; |
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for(i=0; i<64; i++){ |
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for(j=0; j<4; j++){ //FIXME check if this is worth the 1 shift we save |
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ff_h264_lps_range[j*2*64+2*i+0]= |
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ff_h264_lps_range[j*2*64+2*i+1]= lps_range[i][j]; |
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} |
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ff_h264_mlps_state[128 + 2 * i + 0] = 2 * mps_state[i] + 0; |
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ff_h264_mlps_state[128 + 2 * i + 1] = 2 * mps_state[i] + 1; |
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if( i ){ |
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ff_h264_mlps_state[128-2*i-1]= 2*lps_state[i]+0; |
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ff_h264_mlps_state[128-2*i-2]= 2*lps_state[i]+1; |
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}else{ |
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ff_h264_mlps_state[128-2*i-1]= 1; |
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ff_h264_mlps_state[128-2*i-2]= 0; |
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} |
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} |
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for(i=0; i< 63; i++){ |
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ff_h264_last_coeff_flag_offset_8x8[i] = last_coeff_flag_offset_8x8[i]; |
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} |
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initialized = 1; |
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} |
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#ifdef TEST |
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#define SIZE 10240 |
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#include "libavutil/lfg.h" |
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#include "avcodec.h" |
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static inline void put_cabac_bit(CABACContext *c, int b){ |
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put_bits(&c->pb, 1, b); |
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for(;c->outstanding_count; c->outstanding_count--){ |
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put_bits(&c->pb, 1, 1-b); |
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} |
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} |
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static inline void renorm_cabac_encoder(CABACContext *c){ |
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while(c->range < 0x100){ |
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//FIXME optimize |
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if(c->low<0x100){ |
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put_cabac_bit(c, 0); |
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}else if(c->low<0x200){ |
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c->outstanding_count++; |
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c->low -= 0x100; |
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}else{ |
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put_cabac_bit(c, 1); |
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c->low -= 0x200; |
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} |
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c->range+= c->range; |
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c->low += c->low; |
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} |
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} |
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static void put_cabac(CABACContext *c, uint8_t * const state, int bit){ |
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int RangeLPS= ff_h264_lps_range[2*(c->range&0xC0) + *state]; |
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if(bit == ((*state)&1)){ |
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c->range -= RangeLPS; |
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*state = ff_h264_mlps_state[128 + *state]; |
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}else{ |
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c->low += c->range - RangeLPS; |
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c->range = RangeLPS; |
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*state= ff_h264_mlps_state[127 - *state]; |
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} |
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renorm_cabac_encoder(c); |
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} |
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/** |
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* @param bit 0 -> write zero bit, !=0 write one bit |
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*/ |
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static void put_cabac_bypass(CABACContext *c, int bit){ |
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c->low += c->low; |
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if(bit){ |
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c->low += c->range; |
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} |
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//FIXME optimize |
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if(c->low<0x200){ |
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put_cabac_bit(c, 0); |
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}else if(c->low<0x400){ |
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c->outstanding_count++; |
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c->low -= 0x200; |
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}else{ |
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put_cabac_bit(c, 1); |
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c->low -= 0x400; |
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} |
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} |
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/** |
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* |
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* @return the number of bytes written |
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*/ |
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static int put_cabac_terminate(CABACContext *c, int bit){ |
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c->range -= 2; |
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if(!bit){ |
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renorm_cabac_encoder(c); |
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}else{ |
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c->low += c->range; |
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c->range= 2; |
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renorm_cabac_encoder(c); |
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av_assert0(c->low <= 0x1FF); |
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put_cabac_bit(c, c->low>>9); |
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put_bits(&c->pb, 2, ((c->low>>7)&3)|1); |
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flush_put_bits(&c->pb); //FIXME FIXME FIXME XXX wrong |
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} |
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return (put_bits_count(&c->pb)+7)>>3; |
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} |
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int main(void){ |
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CABACContext c; |
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uint8_t b[9*SIZE]; |
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uint8_t r[9*SIZE]; |
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int i; |
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uint8_t state[10]= {0}; |
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AVLFG prng; |
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av_lfg_init(&prng, 1); |
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ff_init_cabac_encoder(&c, b, SIZE); |
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ff_init_cabac_states(); |
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for(i=0; i<SIZE; i++){ |
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if(2*i<SIZE) r[i] = av_lfg_get(&prng) % 7; |
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else r[i] = (i>>8)&1; |
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} |
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for(i=0; i<SIZE; i++){ |
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START_TIMER |
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put_cabac_bypass(&c, r[i]&1); |
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STOP_TIMER("put_cabac_bypass") |
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} |
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for(i=0; i<SIZE; i++){ |
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START_TIMER |
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put_cabac(&c, state, r[i]&1); |
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STOP_TIMER("put_cabac") |
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} |
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put_cabac_terminate(&c, 1); |
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ff_init_cabac_decoder(&c, b, SIZE); |
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memset(state, 0, sizeof(state)); |
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for(i=0; i<SIZE; i++){ |
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START_TIMER |
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if( (r[i]&1) != get_cabac_bypass(&c) ) |
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av_log(NULL, AV_LOG_ERROR, "CABAC bypass failure at %d\n", i); |
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STOP_TIMER("get_cabac_bypass") |
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} |
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for(i=0; i<SIZE; i++){ |
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START_TIMER |
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if( (r[i]&1) != get_cabac_noinline(&c, state) ) |
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av_log(NULL, AV_LOG_ERROR, "CABAC failure at %d\n", i); |
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STOP_TIMER("get_cabac") |
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} |
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if(!get_cabac_terminate(&c)) |
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av_log(NULL, AV_LOG_ERROR, "where's the Terminator?\n"); |
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return 0; |
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} |
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#endif /* TEST */
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