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inline decode_cabac_mb_type for I & P frames, 9 cycles faster on pentium dual. 

Originally committed as revision 16277 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Michael Niedermayer 2008-12-22 16:46:17 +00:00
parent 1952ac3713
commit b68a455313
1 changed files with 13 additions and 22 deletions
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35
libavcodec/h264.c
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@ -4777,25 +4777,9 @@ static int decode_cabac_intra_mb_type(H264Context *h, int ctx_base, int intra_sl
return mb_type;
}
static int decode_cabac_mb_type( H264Context *h ) {
static int decode_cabac_mb_type_b( H264Context *h ) {
MpegEncContext * const s = &h->s;
if( h->slice_type_nos == FF_I_TYPE ) {
return decode_cabac_intra_mb_type(h, 3, 1);
} else if( h->slice_type_nos == FF_P_TYPE ) {
if( get_cabac_noinline( &h->cabac, &h->cabac_state[14] ) == 0 ) {
/* P-type */
if( get_cabac_noinline( &h->cabac, &h->cabac_state[15] ) == 0 ) {
/* P_L0_D16x16, P_8x8 */
return 3 * get_cabac_noinline( &h->cabac, &h->cabac_state[16] );
} else {
/* P_L0_D8x16, P_L0_D16x8 */
return 2 - get_cabac_noinline( &h->cabac, &h->cabac_state[17] );
}
} else {
return decode_cabac_intra_mb_type(h, 17, 0) + 5;
}
} else {
const int mba_xy = h->left_mb_xy[0];
const int mbb_xy = h->top_mb_xy;
int ctx = 0;
@ -4829,7 +4813,6 @@ static int decode_cabac_mb_type( H264Context *h ) {
bits= ( bits<<1 ) | get_cabac_noinline( &h->cabac, &h->cabac_state[27+5] );
return bits - 4; /* B_L0_Bi_* through B_Bi_Bi_* */
}
}
static int decode_cabac_mb_skip( H264Context *h, int mb_x, int mb_y ) {
@ -5365,10 +5348,9 @@ static int decode_mb_cabac(H264Context *h) {
h->prev_mb_skipped = 0;
compute_mb_neighbors(h);
mb_type = decode_cabac_mb_type( h );
assert(mb_type >= 0);
if( h->slice_type_nos == FF_B_TYPE ) {
mb_type = decode_cabac_mb_type_b( h );
if( mb_type < 23 ){
partition_count= b_mb_type_info[mb_type].partition_count;
mb_type= b_mb_type_info[mb_type].type;
@ -5377,14 +5359,23 @@ static int decode_mb_cabac(H264Context *h) {
goto decode_intra_mb;
}
} else if( h->slice_type_nos == FF_P_TYPE ) {
if( mb_type < 5) {
if( get_cabac_noinline( &h->cabac, &h->cabac_state[14] ) == 0 ) {
/* P-type */
if( get_cabac_noinline( &h->cabac, &h->cabac_state[15] ) == 0 ) {
/* P_L0_D16x16, P_8x8 */
mb_type= 3 * get_cabac_noinline( &h->cabac, &h->cabac_state[16] );
} else {
/* P_L0_D8x16, P_L0_D16x8 */
mb_type= 2 - get_cabac_noinline( &h->cabac, &h->cabac_state[17] );
}
partition_count= p_mb_type_info[mb_type].partition_count;
mb_type= p_mb_type_info[mb_type].type;
} else {
mb_type -= 5;
mb_type= decode_cabac_intra_mb_type(h, 17, 0);
goto decode_intra_mb;
}
} else {
mb_type= decode_cabac_intra_mb_type(h, 3, 1);
if(h->slice_type == FF_SI_TYPE && mb_type)
mb_type--;
assert(h->slice_type_nos == FF_I_TYPE);