ffmpeg.c:3256: error: Null Dereference
  pointer `st` last assigned on line 3251 could be null and is dereferenced at line 3256, column 35.

ffmpeg.c:3246:1: start of procedure new_subtitle_stream()
3244. }
3245. 
3246. static void new_subtitle_stream(AVFormatContext *oc)
      ^
3247. {
3248.     AVStream *st;

ffmpeg.c:3251:5: 
3249.     AVCodecContext *subtitle_enc;
3250. 
3251.     st = av_new_stream(oc, oc->nb_streams);
          ^
3252.     if (!st) {
3253.         fprintf(stderr, "Could not alloc stream\n");

libavformat/utils.c:2354:1: start of procedure av_new_stream()
  2352. }
  2353. 
  2354. AVStream *av_new_stream(AVFormatContext *s, int id)
        ^
  2355. {
  2356.     AVStream *st;

libavformat/utils.c:2359:9: Taking true branch
  2357.     int i;
  2358. 
  2359.     if (s->nb_streams >= MAX_STREAMS)
                ^
  2360.         return NULL;
  2361. 

libavformat/utils.c:2360:9: 
  2358. 
  2359.     if (s->nb_streams >= MAX_STREAMS)
  2360.         return NULL;
                ^
  2361. 
  2362.     st = av_mallocz(sizeof(AVStream));

libavformat/utils.c:2394:1: return from a call to av_new_stream
  2392.     s->streams[s->nb_streams++] = st;
  2393.     return st;
  2394. }
        ^
  2395. 
  2396. AVProgram *av_new_program(AVFormatContext *ac, int id)

ffmpeg.c:3252:10: Taking true branch
3250. 
3251.     st = av_new_stream(oc, oc->nb_streams);
3252.     if (!st) {
               ^
3253.         fprintf(stderr, "Could not alloc stream\n");
3254.         av_exit(1);

ffmpeg.c:3253:9: 
3251.     st = av_new_stream(oc, oc->nb_streams);
3252.     if (!st) {
3253.         fprintf(stderr, "Could not alloc stream\n");
              ^
3254.         av_exit(1);
3255.     }

ffmpeg.c:3254:9: Skipping av_exit(): empty list of specs
3252.     if (!st) {
3253.         fprintf(stderr, "Could not alloc stream\n");
3254.         av_exit(1);
              ^
3255.     }
3256.     avcodec_get_context_defaults2(st->codec, CODEC_TYPE_SUBTITLE);

ffmpeg.c:3256:5: 
3254.         av_exit(1);
3255.     }
3256.     avcodec_get_context_defaults2(st->codec, CODEC_TYPE_SUBTITLE);
          ^
3257. 
3258.     bitstream_filters[nb_output_files][oc->nb_streams - 1]= subtitle_bitstream_filters;
