[FFmpeg-cvslog] r19747 - trunk/libavutil/common.h

[jbr]

Author: jbr
Date: Sun Aug 30 17:50:03 2009
New Revision: 19747

Log:
Add function to compute ceil(log2(x)).
Patch by Thilo Borgmann <thilo.borgmann _at_ googlemail.com>

Modified:
   trunk/libavutil/common.h

Modified: trunk/libavutil/common.h
==============================================================================
--- trunk/libavutil/common.h	Sun Aug 30 12:54:16 2009	(r19746)
+++ trunk/libavutil/common.h	Sun Aug 30 17:50:03 2009	(r19747)
@@ -225,6 +225,15 @@ static inline av_const float av_clipf(fl
     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))