ffmpeg.c:3220: error: Null Dereference
  pointer `st` last assigned on line 3215 could be null and is dereferenced at line 3220, column 35.

ffmpeg.c:3210:1: start of procedure new_subtitle_stream()
3208. }
3209. 
3210. static void new_subtitle_stream(AVFormatContext *oc)
      ^
3211. {
3212.     AVStream *st;

ffmpeg.c:3215:5: 
3213.     AVCodecContext *subtitle_enc;
3214. 
3215.     st = av_new_stream(oc, oc->nb_streams);
          ^
3216.     if (!st) {
3217.         fprintf(stderr, "Could not alloc stream\n");

libavformat/utils.c:2342:1: start of procedure av_new_stream()
  2340. }
  2341. 
  2342. AVStream *av_new_stream(AVFormatContext *s, int id)
        ^
  2343. {
  2344.     AVStream *st;

libavformat/utils.c:2347:9: Taking true branch
  2345.     int i;
  2346. 
  2347.     if (s->nb_streams >= MAX_STREAMS)
                ^
  2348.         return NULL;
  2349. 

libavformat/utils.c:2348:9: 
  2346. 
  2347.     if (s->nb_streams >= MAX_STREAMS)
  2348.         return NULL;
                ^
  2349. 
  2350.     st = av_mallocz(sizeof(AVStream));

libavformat/utils.c:2381:1: return from a call to av_new_stream
  2379.     s->streams[s->nb_streams++] = st;
  2380.     return st;
  2381. }
        ^
  2382. 
  2383. AVProgram *av_new_program(AVFormatContext *ac, int id)

ffmpeg.c:3216:10: Taking true branch
3214. 
3215.     st = av_new_stream(oc, oc->nb_streams);
3216.     if (!st) {
               ^
3217.         fprintf(stderr, "Could not alloc stream\n");
3218.         av_exit(1);

ffmpeg.c:3217:9: 
3215.     st = av_new_stream(oc, oc->nb_streams);
3216.     if (!st) {
3217.         fprintf(stderr, "Could not alloc stream\n");
              ^
3218.         av_exit(1);
3219.     }

ffmpeg.c:3218:9: Skipping av_exit(): empty list of specs
3216.     if (!st) {
3217.         fprintf(stderr, "Could not alloc stream\n");
3218.         av_exit(1);
              ^
3219.     }
3220.     avcodec_get_context_defaults2(st->codec, CODEC_TYPE_SUBTITLE);

ffmpeg.c:3220:5: 
3218.         av_exit(1);
3219.     }
3220.     avcodec_get_context_defaults2(st->codec, CODEC_TYPE_SUBTITLE);
          ^
3221. 
3222.     bitstream_filters[nb_output_files][oc->nb_streams - 1]= subtitle_bitstream_filters;
