10l to me. Revert recent changes to ac3_probe() which made misdetection as AC3 too probable.

Originally committed as revision 9931 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/raw.c

@@ -429,7 +429,7 @@ static int ac3_probe(AVProbeData *p)
             first_frames = frames;
     }
     if   (first_frames>=3) return AVPROBE_SCORE_MAX * 3 / 4;
-    else if(max_frames>=2 || first_frames>=1) return AVPROBE_SCORE_MAX / 2;
+    else if(max_frames>=3) return AVPROBE_SCORE_MAX / 2;
     else if(max_frames>=1) return 1;
     else                   return 0;
 }