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6% faster decode_cabac_residual

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Originally committed as revision 4618 to svn://svn.ffmpeg.org/ffmpeg/trunk
pull/126/head
Loren Merritt 20 years ago
parent ca3b0d2719
commit d90cbe5fe8
1 changed files with 38 additions and 34 deletions
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  1. 72
      libavcodec/h264.c

72
libavcodec/h264.c
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@ -5517,9 +5517,6 @@ static int inline decode_cabac_residual( H264Context *h, DCTELEM *block, int cat
static const int significant_coeff_flag_offset[6] = { 0, 15, 29, 44, 47, 297 };
static const int last_significant_coeff_flag_offset[6] = { 0, 15, 29, 44, 47, 251 };
static const int coeff_abs_level_m1_offset[6] = { 227+0, 227+10, 227+20, 227+30, 227+39, 426 };
static const int identity[15] = {
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14
};
static const int significant_coeff_flag_offset_8x8[63] = {
0, 1, 2, 3, 4, 5, 5, 4, 4, 3, 3, 4, 4, 4, 5, 5,
4, 4, 4, 4, 3, 3, 6, 7, 7, 7, 8, 9,10, 9, 8, 7,
@ -5541,12 +5538,9 @@ static int inline decode_cabac_residual( H264Context *h, DCTELEM *block, int cat
int abslevel1 = 1;
int abslevelgt1 = 0;
const int* significant_coeff_ctx_offset;
const int* last_coeff_ctx_offset;
const int significant_coeff_ctx_base = significant_coeff_flag_offset[cat]
+ significant_coeff_flag_field_offset[h->mb_field_decoding_flag];
const int last_coeff_ctx_base = last_significant_coeff_flag_offset[cat]
+ last_significant_coeff_flag_field_offset[h->mb_field_decoding_flag];
uint8_t *significant_coeff_ctx_base;
uint8_t *last_coeff_ctx_base;
uint8_t *abs_level_m1_ctx_base;
/* cat: 0-> DC 16x16 n = 0
* 1-> AC 16x16 n = luma4x4idx
@ -5557,10 +5551,7 @@ static int inline decode_cabac_residual( H264Context *h, DCTELEM *block, int cat
*/
/* read coded block flag */
if( cat == 5 ) {
significant_coeff_ctx_offset = significant_coeff_flag_offset_8x8;
last_coeff_ctx_offset = last_coeff_flag_offset_8x8;
} else {
if( cat != 5 ) {
if( get_cabac( &h->cabac, &h->cabac_state[85 + get_cabac_cbf_ctx( h, cat, n ) ] ) == 0 ) {
if( cat == 1 || cat == 2 )
h->non_zero_count_cache[scan8[n]] = 0;
@ -5569,21 +5560,34 @@ static int inline decode_cabac_residual( H264Context *h, DCTELEM *block, int cat
return 0;
}
significant_coeff_ctx_offset =
last_coeff_ctx_offset = identity;
}
for(last= 0; last < max_coeff - 1; last++) {
int sig_ctx = significant_coeff_ctx_base + significant_coeff_ctx_offset[last];
if( get_cabac( &h->cabac, &h->cabac_state[sig_ctx] )) {
int last_ctx = last_coeff_ctx_base + last_coeff_ctx_offset[last];
index[coeff_count++] = last;
if( get_cabac( &h->cabac, &h->cabac_state[last_ctx] ) ) {
last= max_coeff;
break;
}
}
significant_coeff_ctx_base = h->cabac_state
+ significant_coeff_flag_offset[cat]
+ significant_coeff_flag_field_offset[h->mb_field_decoding_flag];
last_coeff_ctx_base = h->cabac_state
+ last_significant_coeff_flag_offset[cat]
+ last_significant_coeff_flag_field_offset[h->mb_field_decoding_flag];
abs_level_m1_ctx_base = h->cabac_state
+ coeff_abs_level_m1_offset[cat];
if( cat == 5 ) {
#define DECODE_SIGNIFICANCE( coefs, sig_off, last_off ) \
for(last= 0; last < coefs; last++) { \
uint8_t *sig_ctx = significant_coeff_ctx_base + sig_off; \
if( get_cabac( &h->cabac, sig_ctx )) { \
uint8_t *last_ctx = last_coeff_ctx_base + last_off; \
index[coeff_count++] = last; \
if( get_cabac( &h->cabac, last_ctx ) ) { \
last= max_coeff; \
break; \
} \
} \
}
DECODE_SIGNIFICANCE( 63, significant_coeff_flag_offset_8x8[last],
last_coeff_flag_offset_8x8[last] );
} else {
DECODE_SIGNIFICANCE( max_coeff - 1, last, last );
}
if( last == max_coeff -1 ) {
index[coeff_count++] = last;
@ -5604,11 +5608,11 @@ static int inline decode_cabac_residual( H264Context *h, DCTELEM *block, int cat
}
for( i = coeff_count - 1; i >= 0; i-- ) {
int ctx = (abslevelgt1 != 0 ? 0 : FFMIN( 4, abslevel1 )) + coeff_abs_level_m1_offset[cat];
uint8_t *ctx = (abslevelgt1 != 0 ? 0 : FFMIN( 4, abslevel1 )) + abs_level_m1_ctx_base;
int j= scantable[index[i]];
if( get_cabac( &h->cabac, &h->cabac_state[ctx] ) == 0 ) {
if( cat == 0 || cat == 3 ) {
if( get_cabac( &h->cabac, ctx ) == 0 ) {
if( !qmul ) {
if( get_cabac_bypass( &h->cabac ) ) block[j] = -1;
else block[j] = 1;
}else{
@ -5619,8 +5623,8 @@ static int inline decode_cabac_residual( H264Context *h, DCTELEM *block, int cat
abslevel1++;
} else {
int coeff_abs = 2;
ctx = 5 + FFMIN( 4, abslevelgt1 ) + coeff_abs_level_m1_offset[cat];
while( coeff_abs < 15 && get_cabac( &h->cabac, &h->cabac_state[ctx] ) ) {
ctx = 5 + FFMIN( 4, abslevelgt1 ) + abs_level_m1_ctx_base;
while( coeff_abs < 15 && get_cabac( &h->cabac, ctx ) ) {
coeff_abs++;
}
@ -5637,7 +5641,7 @@ static int inline decode_cabac_residual( H264Context *h, DCTELEM *block, int cat
}
}
if( cat == 0 || cat == 3 ) {
if( !qmul ) {
if( get_cabac_bypass( &h->cabac ) ) block[j] = -coeff_abs;
else block[j] = coeff_abs;
}else{
@ -6069,7 +6073,7 @@ decode_intra_mb:
if( IS_INTRA16x16( mb_type ) ) {
int i;
//av_log( s->avctx, AV_LOG_ERROR, "INTRA16x16 DC\n" );
if( decode_cabac_residual( h, h->mb, 0, 0, dc_scan, h->dequant4_coeff[s->qscale], 16) < 0)
if( decode_cabac_residual( h, h->mb, 0, 0, dc_scan, NULL, 16) < 0)
return -1;
if( cbp&15 ) {
for( i = 0; i < 16; i++ ) {
@ -6111,7 +6115,7 @@ decode_intra_mb:
int c;
for( c = 0; c < 2; c++ ) {
//av_log( s->avctx, AV_LOG_ERROR, "INTRA C%d-DC\n",c );
if( decode_cabac_residual(h, h->mb + 256 + 16*4*c, 3, c, chroma_dc_scan, h->dequant4_coeff[h->chroma_qp], 4) < 0)
if( decode_cabac_residual(h, h->mb + 256 + 16*4*c, 3, c, chroma_dc_scan, NULL, 4) < 0)
return -1;
}
}

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