Revert "Merge commit '3ef98937'"

This broke packed_maindata.mp3.mp4
Its unknown to me what this commit would have fixed
Reviewed-by: James Almer <jamrial@gmail.com>

This reverts commit 79127dbb, reversing
changes made to 9fad1ce7.

libavformat/mov.c

@@ -3100,9 +3100,6 @@ static int mov_read_trak(MOVContext *c, AVIOContext *pb, MOVAtom atom)
         st->codec->width = 0; /* let decoder init width/height */
         st->codec->height= 0;
         break;
-    case AV_CODEC_ID_MP3:
-        st->need_parsing = AVSTREAM_PARSE_FULL;
-        break;
     }
 
     // If the duration of the mp3 packets is not constant, then they could need a parser