store a few values in the header as difference to the last

this makes frames a few bytes smaller (0.1% for high bitrate but >1% for low bitrates)

Originally committed as revision 7401 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Michael Niedermayer 2007-01-02 12:24:31 +00:00
parent c62997a587
commit 396a5e6837
3 changed files with 44 additions and 22 deletions

View File

@ -439,6 +439,7 @@ typedef struct SnowContext{
int always_reset;
int version;
int spatial_decomposition_type;
int last_spatial_decomposition_type;
int temporal_decomposition_type;
int spatial_decomposition_count;
int temporal_decomposition_count;
@ -452,15 +453,19 @@ typedef struct SnowContext{
int chroma_v_shift;
int spatial_scalability;
int qlog;
int last_qlog;
int lambda;
int lambda2;
int pass1_rc;
int mv_scale;
int last_mv_scale;
int qbias;
int last_qbias;
#define QBIAS_SHIFT 3
int b_width;
int b_height;
int block_max_depth;
int last_block_max_depth;
Plane plane[MAX_PLANES];
BlockNode *block;
#define ME_CACHE_SIZE 1024
@ -1849,7 +1854,7 @@ static inline void decode_subband_slice_buffered(SnowContext *s, SubBand *b, sli
return;
}
static void reset_contexts(SnowContext *s){
static void reset_contexts(SnowContext *s){ //FIXME better initial contexts
int plane_index, level, orientation;
for(plane_index=0; plane_index<3; plane_index++){
@ -3603,8 +3608,14 @@ static void encode_header(SnowContext *s){
memset(kstate, MID_STATE, sizeof(kstate));
put_rac(&s->c, kstate, s->keyframe);
if(s->keyframe || s->always_reset)
if(s->keyframe || s->always_reset){
reset_contexts(s);
s->last_spatial_decomposition_type=
s->last_qlog=
s->last_qbias=
s->last_mv_scale=
s->last_block_max_depth= 0;
}
if(s->keyframe){
put_symbol(&s->c, s->header_state, s->version, 0);
put_rac(&s->c, s->header_state, s->always_reset);
@ -3627,11 +3638,17 @@ static void encode_header(SnowContext *s){
}
}
}
put_symbol(&s->c, s->header_state, s->spatial_decomposition_type, 0);
put_symbol(&s->c, s->header_state, s->qlog, 1);
put_symbol(&s->c, s->header_state, s->mv_scale, 0);
put_symbol(&s->c, s->header_state, s->qbias, 1);
put_symbol(&s->c, s->header_state, s->block_max_depth, 0);
put_symbol(&s->c, s->header_state, s->spatial_decomposition_type - s->last_spatial_decomposition_type, 1);
put_symbol(&s->c, s->header_state, s->qlog - s->last_qlog , 1);
put_symbol(&s->c, s->header_state, s->mv_scale - s->last_mv_scale, 1);
put_symbol(&s->c, s->header_state, s->qbias - s->last_qbias , 1);
put_symbol(&s->c, s->header_state, s->block_max_depth - s->last_block_max_depth, 1);
s->last_spatial_decomposition_type= s->spatial_decomposition_type;
s->last_qlog = s->qlog;
s->last_qbias = s->qbias;
s->last_mv_scale = s->mv_scale;
s->last_block_max_depth = s->block_max_depth;
}
static int decode_header(SnowContext *s){
@ -3641,8 +3658,14 @@ static int decode_header(SnowContext *s){
memset(kstate, MID_STATE, sizeof(kstate));
s->keyframe= get_rac(&s->c, kstate);
if(s->keyframe || s->always_reset)
if(s->keyframe || s->always_reset){
reset_contexts(s);
s->spatial_decomposition_type=
s->qlog=
s->qbias=
s->mv_scale=
s->block_max_depth= 0;
}
if(s->keyframe){
s->version= get_symbol(&s->c, s->header_state, 0);
if(s->version>0){
@ -3673,16 +3696,16 @@ static int decode_header(SnowContext *s){
}
}
s->spatial_decomposition_type= get_symbol(&s->c, s->header_state, 0);
s->spatial_decomposition_type+= get_symbol(&s->c, s->header_state, 1);
if(s->spatial_decomposition_type > 2){
av_log(s->avctx, AV_LOG_ERROR, "spatial_decomposition_type %d not supported", s->spatial_decomposition_type);
return -1;
}
s->qlog= get_symbol(&s->c, s->header_state, 1);
s->mv_scale= get_symbol(&s->c, s->header_state, 0);
s->qbias= get_symbol(&s->c, s->header_state, 1);
s->block_max_depth= get_symbol(&s->c, s->header_state, 0);
s->qlog += get_symbol(&s->c, s->header_state, 1);
s->mv_scale += get_symbol(&s->c, s->header_state, 1);
s->qbias += get_symbol(&s->c, s->header_state, 1);
s->block_max_depth+= get_symbol(&s->c, s->header_state, 1);
if(s->block_max_depth > 1 || s->block_max_depth < 0){
av_log(s->avctx, AV_LOG_ERROR, "block_max_depth= %d is too large", s->block_max_depth);
s->block_max_depth= 0;
@ -4170,7 +4193,6 @@ redo_frame:
pict->pict_type= FF_I_TYPE;
s->keyframe=1;
s->current_picture.key_frame=1;
reset_contexts(s);
goto redo_frame;
}

View File

@ -141,12 +141,12 @@ f8f51fa737add17f7fecaefa118b57ed *./data/a-ffv1.avi
2654678 ./data/a-ffv1.avi
799d3db687f6cdd7a837ec156efc171f *./data/out.yuv
stddev: 0.00 PSNR:99.99 bytes:7602176
b12ff53580cd8a9ce92ab7a0649e99f9 *./data/a-snow.avi
155948 ./data/a-snow.avi
ed13d6d458ada3973046d469dd4314b5 *./data/a-snow.avi
155842 ./data/a-snow.avi
b3feb1bf17bb4e720da1f1e8b4da4c03 *./data/out.yuv
stddev: 23.19 PSNR:20.81 bytes:7602176
265c4e0c45b2313817fa4d86dccbe6ba *./data/a-snow53.avi
3519574 ./data/a-snow53.avi
ba999e86070aa971376e7f317a022c37 *./data/a-snow53.avi
3519486 ./data/a-snow53.avi
799d3db687f6cdd7a837ec156efc171f *./data/out.yuv
stddev: 0.00 PSNR:99.99 bytes:7602176
2fcbcdc63816e1321bf4b6b5380338d2 *./data/a-dv.dv

View File

@ -141,12 +141,12 @@ d72b0960e162d4998b9acbabb07e99ab *./data/a-ffv1.avi
3525804 ./data/a-ffv1.avi
dde5895817ad9d219f79a52d0bdfb001 *./data/out.yuv
stddev: 0.00 PSNR:99.99 bytes:7602176
4b306a67e21771eba4c61b1cf0f56141 *./data/a-snow.avi
68526 ./data/a-snow.avi
2158b42147fd7a32fc3099148df0700d *./data/a-snow.avi
68432 ./data/a-snow.avi
d2914543504345fad6e5593f66f072bc *./data/out.yuv
stddev: 10.93 PSNR:27.34 bytes:7602176
892221ef4c1debf694a481a5e23e1136 *./data/a-snow53.avi
2722066 ./data/a-snow53.avi
3d0da6aeec9b80c6ee0ff4b747bdd0f0 *./data/a-snow53.avi
2721980 ./data/a-snow53.avi
dde5895817ad9d219f79a52d0bdfb001 *./data/out.yuv
stddev: 0.00 PSNR:99.99 bytes:7602176
af9f474238c9c68cb32e389659ee25ab *./data/a-dv.dv