cabac_functions: Count zeros with ctz if it is fast

When refilling the low bit buffer after get_cabac count the bits with ctz
if the processor has a fast version.

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This commit is contained in:
John Cox 2016-01-20 17:56:30 +00:00 committed by Michael Niedermayer
parent 48f80831ba
commit 5115d8326e
1 changed files with 4 additions and 1 deletions

View File

@ -76,9 +76,12 @@ static inline void renorm_cabac_decoder_once(CABACContext *c){
static void refill2(CABACContext *c){
int i;
unsigned x;
#if !HAVE_FAST_CLZ
x= c->low ^ (c->low-1);
i= 7 - ff_h264_norm_shift[x>>(CABAC_BITS-1)];
#else
i = ff_ctz(c->low) - CABAC_BITS;
#endif
x= -CABAC_MASK;