ffmpeg.c:3564: error: Null Dereference
  pointer `st` last assigned on line 3559 could be null and is dereferenced at line 3564, column 35.

ffmpeg.c:3554:1: start of procedure new_subtitle_stream()
3552. }
3553. 
3554. static void new_subtitle_stream(AVFormatContext *oc)
      ^
3555. {
3556.     AVStream *st;

ffmpeg.c:3559:5: 
3557.     AVCodecContext *subtitle_enc;
3558. 
3559.     st = av_new_stream(oc, oc->nb_streams);
          ^
3560.     if (!st) {
3561.         fprintf(stderr, "Could not alloc stream\n");

libavformat/utils.c:2465:1: start of procedure av_new_stream()
  2463. }
  2464. 
  2465. AVStream *av_new_stream(AVFormatContext *s, int id)
        ^
  2466. {
  2467.     AVStream *st;

libavformat/utils.c:2470:9: Taking true branch
  2468.     int i;
  2469. 
  2470.     if (s->nb_streams >= MAX_STREAMS){
                ^
  2471.         av_log(s, AV_LOG_ERROR, "Too many streams\n");
  2472.         return NULL;

libavformat/utils.c:2471:9: Skipping av_log(): empty list of specs
  2469. 
  2470.     if (s->nb_streams >= MAX_STREAMS){
  2471.         av_log(s, AV_LOG_ERROR, "Too many streams\n");
                ^
  2472.         return NULL;
  2473.     }

libavformat/utils.c:2472:9: 
  2470.     if (s->nb_streams >= MAX_STREAMS){
  2471.         av_log(s, AV_LOG_ERROR, "Too many streams\n");
  2472.         return NULL;
                ^
  2473.     }
  2474. 

libavformat/utils.c:2507:1: return from a call to av_new_stream
  2505.     s->streams[s->nb_streams++] = st;
  2506.     return st;
  2507. }
        ^
  2508. 
  2509. AVProgram *av_new_program(AVFormatContext *ac, int id)

ffmpeg.c:3560:10: Taking true branch
3558. 
3559.     st = av_new_stream(oc, oc->nb_streams);
3560.     if (!st) {
               ^
3561.         fprintf(stderr, "Could not alloc stream\n");
3562.         av_exit(1);

ffmpeg.c:3561:9: 
3559.     st = av_new_stream(oc, oc->nb_streams);
3560.     if (!st) {
3561.         fprintf(stderr, "Could not alloc stream\n");
              ^
3562.         av_exit(1);
3563.     }

ffmpeg.c:3562:9: Skipping av_exit(): empty list of specs
3560.     if (!st) {
3561.         fprintf(stderr, "Could not alloc stream\n");
3562.         av_exit(1);
              ^
3563.     }
3564.     avcodec_get_context_defaults2(st->codec, AVMEDIA_TYPE_SUBTITLE);

ffmpeg.c:3564:5: 
3562.         av_exit(1);
3563.     }
3564.     avcodec_get_context_defaults2(st->codec, AVMEDIA_TYPE_SUBTITLE);
          ^
3565. 
3566.     bitstream_filters[nb_output_files][oc->nb_streams - 1]= subtitle_bitstream_filters;
