avformat/mpeg: Decrease score by 1 for files with very little valid data

Fixes: 8233/PPY6574574605_cut.mp3

Signed-off-by: Michael Niedermayer <[email protected]>
diff --git a/libavformat/mpeg.c b/libavformat/mpeg.c
index 33c0398..265b2bd 100644
--- a/libavformat/mpeg.c
+++ b/libavformat/mpeg.c
@@ -99,7 +99,7 @@
 
     if (sys > invalid && sys * 9 <= pspack * 10)
         return (audio > 12 || vid > 3 || pspack > 2) ? AVPROBE_SCORE_EXTENSION + 2
-                                                     : AVPROBE_SCORE_EXTENSION / 2 + 1; // 1 more than mp3
+                                                     : AVPROBE_SCORE_EXTENSION / 2 + (audio + vid + pspack > 1); // 1 more than mp3
     if (pspack > invalid && (priv1 + vid + audio) * 10 >= pspack * 9)
         return pspack > 2 ? AVPROBE_SCORE_EXTENSION + 2
                           : AVPROBE_SCORE_EXTENSION / 2; // 1 more than .mpg