Add a log2 replacement for systems that haven't quite caught up with the C99

standard library. Originally committed as revision 19395 to svn://svn.ffmpeg.org/ffmpeg/trunk
2009-07-10 19:20:06 +00:00
parent 451ae25724
commit 291fd18a6e
2 changed files with 9 additions and 1 deletions
--- a/libavutil/internal.h
+++ b/libavutil/internal.h
@ -265,6 +265,13 @@ static av_always_inline av_const long long llrint(double x)
 }
 #endif /* HAVE_LLRINT */

+#if !HAVE_LOG2
+static av_always_inline av_const double log2(double x)
+{
+    return log(x) * 1.44269504088896340736;
+}
+#endif /* HAVE_LOG2 */
+
 #if !HAVE_LRINT
 static av_always_inline av_const long int lrint(double x)
 {