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H.264: switch to x264-style tracking of luma/chroma DC NNZ

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Useful so that we don't have to run the hierarchical DC iDCT if there aren't
any coefficients.  Opens up some future opportunities for optimization as well.

Originally committed as revision 26337 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Jason Garrett-Glaser
2011-01-14 21:36:16 +00:00
parent 19fb234e4a
commit 5657d14094
4 changed files with 33 additions and 15 deletions
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11
libavcodec/h264_cabac.c
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@@ -965,6 +965,7 @@ static av_always_inline int get_cabac_cbf_ctx( H264Context *h, int cat, int idx,
nza = h->left_cbp&0x100;
nzb = h-> top_cbp&0x100;
} else {
idx -= CHROMA_DC_BLOCK_INDEX;
nza = (h->left_cbp>>(6+idx))&0x01;
nzb = (h-> top_cbp>>(6+idx))&0x01;
}
@@ -1060,8 +1061,7 @@ static av_always_inline void decode_cabac_residual_internal( H264Context *h, DCT
/* read coded block flag */
if( is_dc || cat != 5 ) {
if( get_cabac( CC, &h->cabac_state[85 + get_cabac_cbf_ctx( h, cat, n, is_dc ) ] ) == 0 ) {
if( !is_dc )
h->non_zero_count_cache[scan8[n]] = 0;
h->non_zero_count_cache[scan8[n]] = 0;
#ifdef CABAC_ON_STACK
h->cabac.range = cc.range ;
@@ -1112,7 +1112,8 @@ static av_always_inline void decode_cabac_residual_internal( H264Context *h, DCT
if( cat == 0 )
h->cbp_table[h->mb_xy] |= 0x100;
else
h->cbp_table[h->mb_xy] |= 0x40 << n;
h->cbp_table[h->mb_xy] |= 0x40 << (n - CHROMA_DC_BLOCK_INDEX);
h->non_zero_count_cache[scan8[n]] = coeff_count;
} else {
if( cat == 5 )
fill_rectangle(&h->non_zero_count_cache[scan8[n]], 2, 2, 8, coeff_count, 1);
@@ -1642,7 +1643,7 @@ decode_intra_mb:
//av_log( s->avctx, AV_LOG_ERROR, "INTRA16x16 DC\n" );
AV_ZERO128(h->mb_luma_dc+0);
AV_ZERO128(h->mb_luma_dc+8);
decode_cabac_residual_dc( h, h->mb_luma_dc, 0, 0, scan, 16);
decode_cabac_residual_dc( h, h->mb_luma_dc, 0, LUMA_DC_BLOCK_INDEX, scan, 16);
if( cbp&15 ) {
qmul = h->dequant4_coeff[0][s->qscale];
@@ -1681,7 +1682,7 @@ decode_intra_mb:
int c;
for( c = 0; c < 2; c++ ) {
//av_log( s->avctx, AV_LOG_ERROR, "INTRA C%d-DC\n",c );
decode_cabac_residual_dc(h, h->mb + 256 + 16*4*c, 3, c, chroma_dc_scan, 4);
decode_cabac_residual_dc(h, h->mb + 256 + 16*4*c, 3, CHROMA_DC_BLOCK_INDEX+c, chroma_dc_scan, 4);
}
}