mp3probe: Detect mp3 stronger with just 200 frames, this should speed up detection

on mp3 streams.
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavformat/mp3dec.c

@@ -63,7 +63,7 @@ static int mp3_read_probe(AVProbeData *p)
     // keep this in sync with ac3 probe, both need to avoid
     // issues with MPEG-files!
     if   (first_frames>=4) return AVPROBE_SCORE_MAX/2+1;
-    else if(max_frames>500)return AVPROBE_SCORE_MAX/2;
+    else if(max_frames>200)return AVPROBE_SCORE_MAX/2;
     else if(max_frames>=4) return AVPROBE_SCORE_MAX/4;
     else if(max_frames>=1) return 1;
     else                   return 0;