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optimization 

Originally committed as revision 3629 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Michael Niedermayer 2004-10-24 02:08:45 +00:00
parent 7b89e963e8
commit 58897665ae
1 changed files with 25 additions and 28 deletions
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53
libavcodec/h264.c
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@ -4153,7 +4153,7 @@ static int decode_cabac_mb_mvd( H264Context *h, int list, int n, int l ) {
}
static int get_cabac_cbf_ctx( H264Context *h, int cat, int idx ) {
static int inline get_cabac_cbf_ctx( H264Context *h, int cat, int idx ) {
int nza, nzb;
int ctx = 0;
@ -4181,19 +4181,18 @@ static int get_cabac_cbf_ctx( H264Context *h, int cat, int idx ) {
return ctx + 4 * cat;
}
static int decode_cabac_residual( H264Context *h, DCTELEM *block, int cat, int n, const uint8_t *scantable, int qp, int max_coeff) {
static int inline decode_cabac_residual( H264Context *h, DCTELEM *block, int cat, int n, const uint8_t *scantable, int qp, int max_coeff) {
const int mb_xy = h->s.mb_x + h->s.mb_y*h->s.mb_stride;
const uint16_t *qmul= dequant_coeff[qp];
static const int significant_coeff_flag_offset[5] = { 0, 15, 29, 44, 47 };
static const int coeff_abs_level_m1_offset[5] = {227+ 0, 227+10, 227+20, 227+30, 227+39 };
int coeff[16];
int index[16];
int i, last;
int coeff_count = 0;
int abslevel1 = 0;
int abslevel1 = 1;
int abslevelgt1 = 0;
/* cat: 0-> DC 16x16 n = 0
@ -4225,24 +4224,31 @@ static int decode_cabac_residual( H264Context *h, DCTELEM *block, int cat, int n
if( last == max_coeff -1 ) {
index[coeff_count++] = last;
}
assert(coeff_count > 0);
if( cat == 0 && coeff_count > 0 )
if( cat == 0 )
h->cbp_table[mb_xy] |= 0x100;
else if( cat == 1 || cat == 2 )
h->non_zero_count_cache[scan8[n]] = coeff_count;
else if( cat == 3 && coeff_count > 0 )
else if( cat == 3 )
h->cbp_table[mb_xy] |= 0x40 << n;
else if( cat == 4 )
else {
assert( cat == 4 );
h->non_zero_count_cache[scan8[16+n]] = coeff_count;
}
for( i = coeff_count - 1; i >= 0; i-- ) {
int ctx = (abslevelgt1 != 0 ? 0 : FFMIN( 4, abslevel1 + 1 )) + coeff_abs_level_m1_offset[cat];
int ctx = (abslevelgt1 != 0 ? 0 : FFMIN( 4, abslevel1 )) + coeff_abs_level_m1_offset[cat];
int j= scantable[index[i]];
if( get_cabac( &h->cabac, &h->cabac_state[ctx] ) == 0 ) {
if( get_cabac_bypass( &h->cabac ) )
coeff[i] = -1;
else
coeff[i] = 1;
if( cat == 0 || cat == 3 ) {
if( get_cabac_bypass( &h->cabac ) ) block[j] = -1;
else block[j] = 1;
}else{
if( get_cabac_bypass( &h->cabac ) ) block[j] = -qmul[j];
else block[j] = qmul[j];
}
abslevel1++;
} else {
@ -4265,26 +4271,17 @@ static int decode_cabac_residual( H264Context *h, DCTELEM *block, int cat, int n
}
}
if( get_cabac_bypass( &h->cabac ) )
coeff[i] = -coeff_abs;
else
coeff[i] = coeff_abs;
if( cat == 0 || cat == 3 ) {
if( get_cabac_bypass( &h->cabac ) ) block[j] = -coeff_abs;
else block[j] = coeff_abs;
}else{
if( get_cabac_bypass( &h->cabac ) ) block[j] = -coeff_abs * qmul[j];
else block[j] = coeff_abs * qmul[j];
}
abslevelgt1++;
}
}
if( cat == 0 || cat == 3 ) { /* DC */
for(i = 0; i < coeff_count; i++) {
block[scantable[ index[i] ]] = coeff[i];
}
} else { /* AC */
for(i = 0; i < coeff_count; i++) {
int j= scantable[index[i]];
block[j] = coeff[i] * qmul[j];
}
}
return 0;
}