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ac3enc: remove a branch in asym_quant() by doing 2 shifts

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This commit is contained in:
Justin Ruggles 2011-06-21 16:14:19 -04:00
parent 0e4dbe2996
commit f21fb76b1b
1 changed files with 2 additions and 8 deletions
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10
libavcodec/ac3enc.c
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@ -1123,15 +1123,9 @@ static inline int sym_quant(int c, int e, int levels)
*/ */
static inline int asym_quant(int c, int e, int qbits) static inline int asym_quant(int c, int e, int qbits)
{ {
int lshift, m, v; int m, v;
lshift = e + qbits - 24; v = (((c << e) >> (24 - qbits)) + 1) >> 1;
if (lshift >= 0)
v = c << lshift;
else
v = c >> (-lshift);
/* rounding */
v = (v + 1) >> 1;
m = (1 << (qbits-1)); m = (1 << (qbits-1));
if (v >= m) if (v >= m)
v = m - 1; v = m - 1;