From c6dbbc4576dd024b97919b8ee0d51a11cf9dbdaa Mon Sep 17 00:00:00 2001 From: Thilo Borgmann Date: Sun, 30 Aug 2009 15:50:03 +0000 Subject: Add function to compute ceil(log2(x)). Patch by Thilo Borgmann Originally committed as revision 19747 to svn://svn.ffmpeg.org/ffmpeg/trunk --- libavutil/common.h | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/libavutil/common.h b/libavutil/common.h index 9fac1c0aa4..0797a79ac0 100644 --- a/libavutil/common.h +++ b/libavutil/common.h @@ -225,6 +225,15 @@ static inline av_const float av_clipf(float a, float amin, float amax) else return a; } +/** Computes ceil(log2(x)). + * @param x value used to compute ceil(log2(x)) + * @return computed ceiling of log2(x) + */ +static inline av_const int av_ceil_log2(int x) +{ + return av_log2((x - 1) << 1); +} + #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)) -- cgit v1.2.3