mirror of https://git.ffmpeg.org/ffmpeg.git
310 lines
8.7 KiB
C
310 lines
8.7 KiB
C
/*
|
|
* 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"
|
|
|
|
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},
|
|
};
|
|
|
|
uint8_t ff_h264_mlps_state[4*64];
|
|
uint8_t ff_h264_lps_range[4*2*64];
|
|
uint8_t ff_h264_lps_state[2*64];
|
|
uint8_t ff_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,
|
|
};
|
|
|
|
const uint8_t ff_h264_norm_shift[512]= {
|
|
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,
|
|
};
|
|
|
|
/**
|
|
*
|
|
* @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(CABACContext *c){
|
|
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]=
|
|
ff_h264_mps_state[2*i+0]= 2*mps_state[i]+0;
|
|
ff_h264_mlps_state[128+2*i+1]=
|
|
ff_h264_mps_state[2*i+1]= 2*mps_state[i]+1;
|
|
|
|
if( i ){
|
|
ff_h264_lps_state[2*i+0]=
|
|
ff_h264_mlps_state[128-2*i-1]= 2*lps_state[i]+0;
|
|
ff_h264_lps_state[2*i+1]=
|
|
ff_h264_mlps_state[128-2*i-2]= 2*lps_state[i]+1;
|
|
}else{
|
|
ff_h264_lps_state[2*i+0]=
|
|
ff_h264_mlps_state[128-2*i-1]= 1;
|
|
ff_h264_lps_state[2*i+1]=
|
|
ff_h264_mlps_state[128-2*i-2]= 0;
|
|
}
|
|
}
|
|
}
|
|
|
|
#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= ff_h264_mps_state[*state];
|
|
}else{
|
|
c->low += c->range - RangeLPS;
|
|
c->range = RangeLPS;
|
|
*state= ff_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);
|
|
|
|
assert(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(&c);
|
|
|
|
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 */
|