patch from http://www.freebsd.org/cgi/cvsweb.cgi/ports/multimedia/ffmpeg-devel/files/patch-libavcodec::x264.c

(math.h needed for log2() at least)

Originally committed as revision 4426 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/x264.c

@@ -19,6 +19,7 @@
 
 #include "avcodec.h"
 #include <x264.h>
+#include <math.h>
 
 typedef struct X264Context {
     x264_param_t params;