ffmpeg.c:3631: error: Integer Overflow L2
  ([0, +oo] - 1):unsigned32 by call to `new_subtitle_stream`.

ffmpeg.c:3631:5: Call
3629.     }
3630.     oc = output_files[nb_output_files - 1];
3631.     new_subtitle_stream(oc);
          ^
3632. }
3633. 

ffmpeg.c:3560:1: <LHS trace>
3558. }
3559. 
3560. static void new_subtitle_stream(AVFormatContext *oc)
      ^
3561. {
3562.     AVStream *st;

ffmpeg.c:3560:1: Parameter `oc->nb_streams`
  3558. }
  3559. 
  3560. static void new_subtitle_stream(AVFormatContext *oc)
        ^
  3561. {
  3562.     AVStream *st;

ffmpeg.c:3565:10: Call
  3563.     AVCodecContext *subtitle_enc;
  3564. 
  3565.     st = av_new_stream(oc, streamid_map[oc->nb_streams]);
                 ^
  3566.     if (!st) {
  3567.         fprintf(stderr, "Could not alloc stream\n");

libavformat/utils.c:2495:1: Parameter `s->nb_streams`
    2493. }
    2494. 
    2495. AVStream *av_new_stream(AVFormatContext *s, int id)
          ^
    2496. {
    2497.     AVStream *st;

ffmpeg.c:3572:5: Binary operation: ([0, +oo] - 1):unsigned32 by call to `new_subtitle_stream` 
  3570.     avcodec_get_context_defaults2(st->codec, AVMEDIA_TYPE_SUBTITLE);
  3571. 
  3572.     bitstream_filters[nb_output_files][oc->nb_streams - 1]= subtitle_bitstream_filters;
            ^
  3573.     subtitle_bitstream_filters= NULL;
  3574. 
