diff options
Diffstat (limited to 'ffmpeg1/libavcodec/cabac.c')
| -rw-r--r-- | ffmpeg1/libavcodec/cabac.c | 319 |
1 files changed, 319 insertions, 0 deletions
diff --git a/ffmpeg1/libavcodec/cabac.c b/ffmpeg1/libavcodec/cabac.c new file mode 100644 index 0000000..187b7dc --- /dev/null +++ b/ffmpeg1/libavcodec/cabac.c @@ -0,0 +1,319 @@ +/* + * H.26L/H.264/AVC/JVT/14496-10/... encoder/decoder + * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at> + * + * This file is part of FFmpeg. + * + * FFmpeg is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * FFmpeg is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with FFmpeg; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +/** + * @file + * Context Adaptive Binary Arithmetic Coder. + */ + +#include <string.h> + +#include "libavutil/common.h" +#include "get_bits.h" +#include "cabac.h" +#include "cabac_functions.h" + +uint8_t ff_h264_cabac_tables[512 + 4*2*64 + 4*64 + 63] = { + 9,8,7,7,6,6,6,6,5,5,5,5,5,5,5,5, + 4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4, + 3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3, + 3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3, + 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2, + 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2, + 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2, + 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2, + 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, + 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, + 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, + 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, + 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, + 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, + 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, + 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, + 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, + 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, + 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, + 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, +}; + +static const uint8_t lps_range[64][4]= { +{128,176,208,240}, {128,167,197,227}, {128,158,187,216}, {123,150,178,205}, +{116,142,169,195}, {111,135,160,185}, {105,128,152,175}, {100,122,144,166}, +{ 95,116,137,158}, { 90,110,130,150}, { 85,104,123,142}, { 81, 99,117,135}, +{ 77, 94,111,128}, { 73, 89,105,122}, { 69, 85,100,116}, { 66, 80, 95,110}, +{ 62, 76, 90,104}, { 59, 72, 86, 99}, { 56, 69, 81, 94}, { 53, 65, 77, 89}, +{ 51, 62, 73, 85}, { 48, 59, 69, 80}, { 46, 56, 66, 76}, { 43, 53, 63, 72}, +{ 41, 50, 59, 69}, { 39, 48, 56, 65}, { 37, 45, 54, 62}, { 35, 43, 51, 59}, +{ 33, 41, 48, 56}, { 32, 39, 46, 53}, { 30, 37, 43, 50}, { 29, 35, 41, 48}, +{ 27, 33, 39, 45}, { 26, 31, 37, 43}, { 24, 30, 35, 41}, { 23, 28, 33, 39}, +{ 22, 27, 32, 37}, { 21, 26, 30, 35}, { 20, 24, 29, 33}, { 19, 23, 27, 31}, +{ 18, 22, 26, 30}, { 17, 21, 25, 28}, { 16, 20, 23, 27}, { 15, 19, 22, 25}, +{ 14, 18, 21, 24}, { 14, 17, 20, 23}, { 13, 16, 19, 22}, { 12, 15, 18, 21}, +{ 12, 14, 17, 20}, { 11, 14, 16, 19}, { 11, 13, 15, 18}, { 10, 12, 15, 17}, +{ 10, 12, 14, 16}, { 9, 11, 13, 15}, { 9, 11, 12, 14}, { 8, 10, 12, 14}, +{ 8, 9, 11, 13}, { 7, 9, 11, 12}, { 7, 9, 10, 12}, { 7, 8, 10, 11}, +{ 6, 8, 9, 11}, { 6, 7, 9, 10}, { 6, 7, 8, 9}, { 2, 2, 2, 2}, +}; + +static uint8_t h264_lps_state[2*64]; +static uint8_t h264_mps_state[2*64]; + +static const uint8_t mps_state[64]= { + 1, 2, 3, 4, 5, 6, 7, 8, + 9,10,11,12,13,14,15,16, + 17,18,19,20,21,22,23,24, + 25,26,27,28,29,30,31,32, + 33,34,35,36,37,38,39,40, + 41,42,43,44,45,46,47,48, + 49,50,51,52,53,54,55,56, + 57,58,59,60,61,62,62,63, +}; + +static const uint8_t lps_state[64]= { + 0, 0, 1, 2, 2, 4, 4, 5, + 6, 7, 8, 9, 9,11,11,12, + 13,13,15,15,16,16,18,18, + 19,19,21,21,22,22,23,24, + 24,25,26,26,27,27,28,29, + 29,30,30,30,31,32,32,33, + 33,33,34,34,35,35,35,36, + 36,36,37,37,37,38,38,63, +}; + +static const uint8_t last_coeff_flag_offset_8x8[63] = { + 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, + 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, + 3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, + 5, 5, 5, 5, 6, 6, 6, 6, 7, 7, 7, 7, 8, 8, 8 +}; + +/** + * + * @param buf_size size of buf in bits + */ +void ff_init_cabac_encoder(CABACContext *c, uint8_t *buf, int buf_size){ + init_put_bits(&c->pb, buf, buf_size); + + c->low= 0; + c->range= 0x1FE; + c->outstanding_count= 0; + c->pb.bit_left++; //avoids firstBitFlag +} + +/** + * + * @param buf_size size of buf in bits + */ +void ff_init_cabac_decoder(CABACContext *c, const uint8_t *buf, int buf_size){ + c->bytestream_start= + c->bytestream= buf; + c->bytestream_end= buf + buf_size; + +#if CABAC_BITS == 16 + c->low = (*c->bytestream++)<<18; + c->low+= (*c->bytestream++)<<10; +#else + c->low = (*c->bytestream++)<<10; +#endif + c->low+= ((*c->bytestream++)<<2) + 2; + c->range= 0x1FE; +} + +void ff_init_cabac_states(void) +{ + int i, j; + + for(i=0; i<64; i++){ + for(j=0; j<4; j++){ //FIXME check if this is worth the 1 shift we save + ff_h264_lps_range[j*2*64+2*i+0]= + ff_h264_lps_range[j*2*64+2*i+1]= lps_range[i][j]; + } + + ff_h264_mlps_state[128+2*i+0]= + h264_mps_state[2 * i + 0] = 2 * mps_state[i] + 0; + ff_h264_mlps_state[128+2*i+1]= + h264_mps_state[2 * i + 1] = 2 * mps_state[i] + 1; + + if( i ){ + h264_lps_state[2*i+0]= + ff_h264_mlps_state[128-2*i-1]= 2*lps_state[i]+0; + h264_lps_state[2*i+1]= + ff_h264_mlps_state[128-2*i-2]= 2*lps_state[i]+1; + }else{ + h264_lps_state[2*i+0]= + ff_h264_mlps_state[128-2*i-1]= 1; + h264_lps_state[2*i+1]= + ff_h264_mlps_state[128-2*i-2]= 0; + } + } + for(i=0; i< 63; i++){ + ff_h264_last_coeff_flag_offset_8x8[i] = last_coeff_flag_offset_8x8[i]; + } +} + +#ifdef TEST +#define SIZE 10240 + +#include "libavutil/lfg.h" +#include "avcodec.h" +#include "cabac.h" + +static inline void put_cabac_bit(CABACContext *c, int b){ + put_bits(&c->pb, 1, b); + for(;c->outstanding_count; c->outstanding_count--){ + put_bits(&c->pb, 1, 1-b); + } +} + +static inline void renorm_cabac_encoder(CABACContext *c){ + while(c->range < 0x100){ + //FIXME optimize + if(c->low<0x100){ + put_cabac_bit(c, 0); + }else if(c->low<0x200){ + c->outstanding_count++; + c->low -= 0x100; + }else{ + put_cabac_bit(c, 1); + c->low -= 0x200; + } + + c->range+= c->range; + c->low += c->low; + } +} + +static void put_cabac(CABACContext *c, uint8_t * const state, int bit){ + int RangeLPS= ff_h264_lps_range[2*(c->range&0xC0) + *state]; + + if(bit == ((*state)&1)){ + c->range -= RangeLPS; + *state = h264_mps_state[*state]; + }else{ + c->low += c->range - RangeLPS; + c->range = RangeLPS; + *state= h264_lps_state[*state]; + } + + renorm_cabac_encoder(c); +} + +/** + * @param bit 0 -> write zero bit, !=0 write one bit + */ +static void put_cabac_bypass(CABACContext *c, int bit){ + c->low += c->low; + + if(bit){ + c->low += c->range; + } +//FIXME optimize + if(c->low<0x200){ + put_cabac_bit(c, 0); + }else if(c->low<0x400){ + c->outstanding_count++; + c->low -= 0x200; + }else{ + put_cabac_bit(c, 1); + c->low -= 0x400; + } +} + +/** + * + * @return the number of bytes written + */ +static int put_cabac_terminate(CABACContext *c, int bit){ + c->range -= 2; + + if(!bit){ + renorm_cabac_encoder(c); + }else{ + c->low += c->range; + c->range= 2; + + renorm_cabac_encoder(c); + + av_assert0(c->low <= 0x1FF); + put_cabac_bit(c, c->low>>9); + put_bits(&c->pb, 2, ((c->low>>7)&3)|1); + + flush_put_bits(&c->pb); //FIXME FIXME FIXME XXX wrong + } + + return (put_bits_count(&c->pb)+7)>>3; +} + +int main(void){ + CABACContext c; + uint8_t b[9*SIZE]; + uint8_t r[9*SIZE]; + int i; + uint8_t state[10]= {0}; + AVLFG prng; + + av_lfg_init(&prng, 1); + ff_init_cabac_encoder(&c, b, SIZE); + ff_init_cabac_states(); + + for(i=0; i<SIZE; i++){ + if(2*i<SIZE) r[i] = av_lfg_get(&prng) % 7; + else r[i] = (i>>8)&1; + } + + for(i=0; i<SIZE; i++){ +START_TIMER + put_cabac_bypass(&c, r[i]&1); +STOP_TIMER("put_cabac_bypass") + } + + for(i=0; i<SIZE; i++){ +START_TIMER + put_cabac(&c, state, r[i]&1); +STOP_TIMER("put_cabac") + } + + put_cabac_terminate(&c, 1); + + ff_init_cabac_decoder(&c, b, SIZE); + + memset(state, 0, sizeof(state)); + + for(i=0; i<SIZE; i++){ +START_TIMER + if( (r[i]&1) != get_cabac_bypass(&c) ) + av_log(NULL, AV_LOG_ERROR, "CABAC bypass failure at %d\n", i); +STOP_TIMER("get_cabac_bypass") + } + + for(i=0; i<SIZE; i++){ +START_TIMER + if( (r[i]&1) != get_cabac(&c, state) ) + av_log(NULL, AV_LOG_ERROR, "CABAC failure at %d\n", i); +STOP_TIMER("get_cabac") + } + if(!get_cabac_terminate(&c)) + av_log(NULL, AV_LOG_ERROR, "where's the Terminator?\n"); + + return 0; +} + +#endif /* TEST */ |