ffmpeg/libavcodec/h263.h

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/*
* H263 internal header
*
* 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
*/
#ifndef AVCODEC_H263_H
#define AVCODEC_H263_H
// The defines below define the number of bits that are read at once for
// reading vlc values. Changing these may improve speed and data cache needs
// be aware though that decreasing them may need the number of stages that is
// passed to get_vlc* to be increased.
#define INTRA_MCBPC_VLC_BITS 6
#define INTER_MCBPC_VLC_BITS 7
#define CBPY_VLC_BITS 6
#define TEX_VLC_BITS 9
extern const AVRational ff_h263_pixel_aspect[16];
extern const uint8_t cbpy_tab[16][2];
extern const uint8_t mvtab[33][2];
extern const uint8_t intra_MCBPC_code[9];
extern const uint8_t intra_MCBPC_bits[9];
extern const uint8_t inter_MCBPC_code[28];
extern const uint8_t inter_MCBPC_bits[28];
extern VLC intra_MCBPC_vlc;
extern VLC inter_MCBPC_vlc;
extern VLC cbpy_vlc;
extern RLTable rl_inter;
int h263_decode_motion(MpegEncContext * s, int pred, int f_code);
av_const int ff_h263_aspect_to_info(AVRational aspect);
static inline int h263_get_motion_length(MpegEncContext * s, int val, int f_code){
int l, bit_size, code;
if (val == 0) {
return mvtab[0][1];
} else {
bit_size = f_code - 1;
/* modulo encoding */
l= INT_BIT - 6 - bit_size;
val = (val<<l)>>l;
val--;
code = (val >> bit_size) + 1;
return mvtab[code][1] + 1 + bit_size;
}
}
static inline void ff_h263_encode_motion_vector(MpegEncContext * s, int x, int y, int f_code){
if(s->flags2 & CODEC_FLAG2_NO_OUTPUT){
skip_put_bits(&s->pb,
h263_get_motion_length(s, x, f_code)
+h263_get_motion_length(s, y, f_code));
}else{
ff_h263_encode_motion(s, x, f_code);
ff_h263_encode_motion(s, y, f_code);
}
}
static inline int get_p_cbp(MpegEncContext * s,
DCTELEM block[6][64],
int motion_x, int motion_y){
int cbp, i;
if(s->flags & CODEC_FLAG_CBP_RD){
int best_cbpy_score= INT_MAX;
int best_cbpc_score= INT_MAX;
int cbpc = (-1), cbpy= (-1);
const int offset= (s->mv_type==MV_TYPE_16X16 ? 0 : 16) + (s->dquant ? 8 : 0);
const int lambda= s->lambda2 >> (FF_LAMBDA_SHIFT - 6);
for(i=0; i<4; i++){
int score= inter_MCBPC_bits[i + offset] * lambda;
if(i&1) score += s->coded_score[5];
if(i&2) score += s->coded_score[4];
if(score < best_cbpc_score){
best_cbpc_score= score;
cbpc= i;
}
}
for(i=0; i<16; i++){
int score= cbpy_tab[i ^ 0xF][1] * lambda;
if(i&1) score += s->coded_score[3];
if(i&2) score += s->coded_score[2];
if(i&4) score += s->coded_score[1];
if(i&8) score += s->coded_score[0];
if(score < best_cbpy_score){
best_cbpy_score= score;
cbpy= i;
}
}
cbp= cbpc + 4*cbpy;
if ((motion_x | motion_y | s->dquant) == 0 && s->mv_type==MV_TYPE_16X16){
if(best_cbpy_score + best_cbpc_score + 2*lambda >= 0)
cbp= 0;
}
for (i = 0; i < 6; i++) {
if (s->block_last_index[i] >= 0 && ((cbp >> (5 - i))&1)==0 ){
s->block_last_index[i]= -1;
s->dsp.clear_block(s->block[i]);
}
}
}else{
cbp= 0;
for (i = 0; i < 6; i++) {
if (s->block_last_index[i] >= 0)
cbp |= 1 << (5 - i);
}
}
return cbp;
}
static inline int get_b_cbp(MpegEncContext * s, DCTELEM block[6][64],
int motion_x, int motion_y, int mb_type){
int cbp=0, i;
if(s->flags & CODEC_FLAG_CBP_RD){
int score=0;
const int lambda= s->lambda2 >> (FF_LAMBDA_SHIFT - 6);
for(i=0; i<6; i++){
if(s->coded_score[i] < 0){
score += s->coded_score[i];
cbp |= 1 << (5 - i);
}
}
if(cbp){
int zero_score= -6;
if ((motion_x | motion_y | s->dquant | mb_type) == 0){
zero_score-= 4; //2*MV + mb_type + cbp bit
}
zero_score*= lambda;
if(zero_score <= score){
cbp=0;
}
}
for (i = 0; i < 6; i++) {
if (s->block_last_index[i] >= 0 && ((cbp >> (5 - i))&1)==0 ){
s->block_last_index[i]= -1;
s->dsp.clear_block(s->block[i]);
}
}
}else{
for (i = 0; i < 6; i++) {
if (s->block_last_index[i] >= 0)
cbp |= 1 << (5 - i);
}
}
return cbp;
}
#endif