diff options
Diffstat (limited to 'libavutil/common.h')
-rw-r--r-- | libavutil/common.h | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/libavutil/common.h b/libavutil/common.h index d054f87c5b..6404076a13 100644 --- a/libavutil/common.h +++ b/libavutil/common.h @@ -192,6 +192,20 @@ static inline av_const int av_ceil_log2_c(int x) return av_log2((x - 1) << 1); } +/** + * Count number of bits set to one in x + * @param x value to count bits of + * @return the number of bits set to one in x + */ +static inline av_const int av_popcount_c(uint32_t x) +{ + x -= (x >> 1) & 0x55555555; + x = (x & 0x33333333) + ((x >> 2) & 0x33333333); + x = (x + (x >> 4)) & 0x0F0F0F0F; + x += x >> 8; + return (x + (x >> 16)) & 0x3F; +} + #define MKTAG(a,b,c,d) ((a) | ((b) << 8) | ((c) << 16) | ((d) << 24)) #define MKBETAG(a,b,c,d) ((d) | ((c) << 8) | ((b) << 16) | ((a) << 24)) @@ -351,3 +365,6 @@ static inline av_const int av_ceil_log2_c(int x) #ifndef av_clipf # define av_clipf av_clipf_c #endif +#ifndef av_popcount +# define av_popcount av_popcount_c +#endif |