ffmpeg.c:3574: error: Null Dereference
  pointer `st` last assigned on line 3569 could be null and is dereferenced at line 3574, column 35.

ffmpeg.c:3564:1: start of procedure new_subtitle_stream()
3562. }
3563. 
3564. static void new_subtitle_stream(AVFormatContext *oc)
      ^
3565. {
3566.     AVStream *st;

ffmpeg.c:3569:5: 
3567.     AVCodecContext *subtitle_enc;
3568. 
3569.     st = av_new_stream(oc, streamid_map[oc->nb_streams]);
          ^
3570.     if (!st) {
3571.         fprintf(stderr, "Could not alloc stream\n");

libavformat/utils.c:2501:1: start of procedure av_new_stream()
  2499. }
  2500. 
  2501. AVStream *av_new_stream(AVFormatContext *s, int id)
        ^
  2502. {
  2503.     AVStream *st;

libavformat/utils.c:2506:9: Taking true branch
  2504.     int i;
  2505. 
  2506.     if (s->nb_streams >= MAX_STREAMS){
                ^
  2507.         av_log(s, AV_LOG_ERROR, "Too many streams\n");
  2508.         return NULL;

libavformat/utils.c:2507:9: Skipping av_log(): empty list of specs
  2505. 
  2506.     if (s->nb_streams >= MAX_STREAMS){
  2507.         av_log(s, AV_LOG_ERROR, "Too many streams\n");
                ^
  2508.         return NULL;
  2509.     }

libavformat/utils.c:2508:9: 
  2506.     if (s->nb_streams >= MAX_STREAMS){
  2507.         av_log(s, AV_LOG_ERROR, "Too many streams\n");
  2508.         return NULL;
                ^
  2509.     }
  2510. 

libavformat/utils.c:2543:1: return from a call to av_new_stream
  2541.     s->streams[s->nb_streams++] = st;
  2542.     return st;
  2543. }
        ^
  2544. 
  2545. AVProgram *av_new_program(AVFormatContext *ac, int id)

ffmpeg.c:3570:10: Taking true branch
3568. 
3569.     st = av_new_stream(oc, streamid_map[oc->nb_streams]);
3570.     if (!st) {
               ^
3571.         fprintf(stderr, "Could not alloc stream\n");
3572.         ffmpeg_exit(1);

ffmpeg.c:3571:9: 
3569.     st = av_new_stream(oc, streamid_map[oc->nb_streams]);
3570.     if (!st) {
3571.         fprintf(stderr, "Could not alloc stream\n");
              ^
3572.         ffmpeg_exit(1);
3573.     }

ffmpeg.c:3572:9: Skipping ffmpeg_exit(): empty list of specs
3570.     if (!st) {
3571.         fprintf(stderr, "Could not alloc stream\n");
3572.         ffmpeg_exit(1);
              ^
3573.     }
3574.     avcodec_get_context_defaults2(st->codec, AVMEDIA_TYPE_SUBTITLE);

ffmpeg.c:3574:5: 
3572.         ffmpeg_exit(1);
3573.     }
3574.     avcodec_get_context_defaults2(st->codec, AVMEDIA_TYPE_SUBTITLE);
          ^
3575. 
3576.     bitstream_filters[nb_output_files][oc->nb_streams - 1]= subtitle_bitstream_filters;
