emms was missing, found by juanjo but he didnt commit it?!

git-svn-id: file:///var/local/repositories/ffmpeg/trunk@374 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

libavcodec/mpeg12.c

@@ -1411,6 +1411,7 @@ static int mpeg_decode_slice(AVCodecContext *avctx,
             break;
         MPV_decode_mb(s, s->block);
     }
+    emms_c();
 
     /* end of slice reached */
     if (s->mb_x == (s->mb_width - 1) &&