More accurate value for log2(1)

git-svn-id: file:///var/local/repositories/ffmpeg/trunk@21946 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

libavutil/mathematics.h

@@ -36,7 +36,7 @@
 #define M_LN10         2.30258509299404568402  /* log_e 10 */
 #endif
 #ifndef M_LOG2_10
-#define M_LOG2_10      3.32192809488736218171  /* log_2 10 */
+#define M_LOG2_10      3.32192809488736234787  /* log_2 10 */
 #endif
 #ifndef M_PI
 #define M_PI           3.14159265358979323846  /* pi */