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copy cabac context onto the stack for the c code in decode_cabac_residual() (15% faster on P3 but still slower then the current asm) 

Originally committed as revision 6725 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Michael Niedermayer 2006-10-17 23:59:21 +00:00
parent eb73bf723d
commit 30865e2aa1
1 changed files with 36 additions and 13 deletions
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49
libavcodec/h264.c
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@ -6077,6 +6077,20 @@ static int decode_cabac_residual( H264Context *h, DCTELEM *block, int cat, int n
uint8_t *last_coeff_ctx_base;
uint8_t *abs_level_m1_ctx_base;
#ifndef ARCH_X86
#define CABAC_ON_STACK
#endif
#ifdef CABAC_ON_STACK
#define CC &cc
CABACContext cc;
cc.range = h->cabac.range;
cc.low = h->cabac.low;
cc.bytestream= h->cabac.bytestream;
#else
#define CC &h->cabac
#endif
/* cat: 0-> DC 16x16 n = 0
* 1-> AC 16x16 n = luma4x4idx
* 2-> Luma4x4 n = luma4x4idx
@ -6087,12 +6101,16 @@ static int decode_cabac_residual( H264Context *h, DCTELEM *block, int cat, int n
/* read coded block flag */
if( cat != 5 ) {
if( get_cabac( &h->cabac, &h->cabac_state[85 + get_cabac_cbf_ctx( h, cat, n ) ] ) == 0 ) {
if( get_cabac( CC, &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;
else if( cat == 4 )
h->non_zero_count_cache[scan8[16+n]] = 0;
#ifdef CABAC_ON_STACK
h->cabac.range = cc.range ;
h->cabac.low = cc.low ;
h->cabac.bytestream= cc.bytestream;
#endif
return 0;
}
}
@ -6108,10 +6126,10 @@ static int decode_cabac_residual( H264Context *h, DCTELEM *block, int cat, int n
#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 )) { \
if( get_cabac( CC, sig_ctx )) { \
uint8_t *last_ctx = last_coeff_ctx_base + last_off; \
index[coeff_count++] = last; \
if( get_cabac( &h->cabac, last_ctx ) ) { \
if( get_cabac( CC, last_ctx ) ) { \
last= max_coeff; \
break; \
} \
@ -6124,7 +6142,7 @@ static int decode_cabac_residual( H264Context *h, DCTELEM *block, int cat, int n
DECODE_SIGNIFICANCE( 63, sig_off[last], last_coeff_flag_offset_8x8[last] );
} else {
#ifdef ARCH_X86
coeff_count= decode_significance_x86(&h->cabac, max_coeff, significant_coeff_ctx_base, index);
coeff_count= decode_significance_x86(CC, max_coeff, significant_coeff_ctx_base, index);
#else
DECODE_SIGNIFICANCE( max_coeff - 1, last, last );
#endif
@ -6148,12 +6166,12 @@ static int decode_cabac_residual( H264Context *h, DCTELEM *block, int cat, int n
uint8_t *ctx = (abslevelgt1 != 0 ? 0 : FFMIN( 4, abslevel1 )) + abs_level_m1_ctx_base;
int j= scantable[index[i]];
if( get_cabac( &h->cabac, ctx ) == 0 ) {
if( get_cabac( CC, ctx ) == 0 ) {
if( !qmul ) {
if( get_cabac_bypass( &h->cabac ) ) block[j] = -1;
if( get_cabac_bypass( CC ) ) block[j] = -1;
else block[j] = 1;
}else{
if( get_cabac_bypass( &h->cabac ) ) block[j] = (-qmul[j] + 32) >> 6;
if( get_cabac_bypass( CC ) ) block[j] = (-qmul[j] + 32) >> 6;
else block[j] = ( qmul[j] + 32) >> 6;
}
@ -6161,34 +6179,39 @@ static int decode_cabac_residual( H264Context *h, DCTELEM *block, int cat, int n
} else {
int coeff_abs = 2;
ctx = 5 + FFMIN( 4, abslevelgt1 ) + abs_level_m1_ctx_base;
while( coeff_abs < 15 && get_cabac( &h->cabac, ctx ) ) {
while( coeff_abs < 15 && get_cabac( CC, ctx ) ) {
coeff_abs++;
}
if( coeff_abs >= 15 ) {
int j = 0;
while( get_cabac_bypass( &h->cabac ) ) {
while( get_cabac_bypass( CC ) ) {
j++;
}
coeff_abs=1;
while( j-- ) {
coeff_abs += coeff_abs + get_cabac_bypass( &h->cabac );
coeff_abs += coeff_abs + get_cabac_bypass( CC );
}
coeff_abs+= 14;
}
if( !qmul ) {
if( get_cabac_bypass( &h->cabac ) ) block[j] = -coeff_abs;
if( get_cabac_bypass( CC ) ) block[j] = -coeff_abs;
else block[j] = coeff_abs;
}else{
if( get_cabac_bypass( &h->cabac ) ) block[j] = (-coeff_abs * qmul[j] + 32) >> 6;
if( get_cabac_bypass( CC ) ) block[j] = (-coeff_abs * qmul[j] + 32) >> 6;
else block[j] = ( coeff_abs * qmul[j] + 32) >> 6;
}
abslevelgt1++;
}
}
#ifdef CABAC_ON_STACK
h->cabac.range = cc.range ;
h->cabac.low = cc.low ;
h->cabac.bytestream= cc.bytestream;
#endif
return 0;
}