ffmpeg.c:3497: error: Null Dereference
  pointer `st` last assigned on line 3492 could be null and is dereferenced at line 3497, column 35.

ffmpeg.c:3486:1: start of procedure new_audio_stream()
3484. }
3485. 
3486. static void new_audio_stream(AVFormatContext *oc)
      ^
3487. {
3488.     AVStream *st;

ffmpeg.c:3492:5: 
3490.     enum CodecID codec_id;
3491. 
3492.     st = av_new_stream(oc, streamid_map[oc->nb_streams]);
          ^
3493.     if (!st) {
3494.         fprintf(stderr, "Could not alloc stream\n");

libavformat/utils.c:2495:1: start of procedure av_new_stream()
  2493. }
  2494. 
  2495. AVStream *av_new_stream(AVFormatContext *s, int id)
        ^
  2496. {
  2497.     AVStream *st;

libavformat/utils.c:2500:9: Taking true branch
  2498.     int i;
  2499. 
  2500.     if (s->nb_streams >= MAX_STREAMS){
                ^
  2501.         av_log(s, AV_LOG_ERROR, "Too many streams\n");
  2502.         return NULL;

libavformat/utils.c:2501:9: Skipping av_log(): empty list of specs
  2499. 
  2500.     if (s->nb_streams >= MAX_STREAMS){
  2501.         av_log(s, AV_LOG_ERROR, "Too many streams\n");
                ^
  2502.         return NULL;
  2503.     }

libavformat/utils.c:2502:9: 
  2500.     if (s->nb_streams >= MAX_STREAMS){
  2501.         av_log(s, AV_LOG_ERROR, "Too many streams\n");
  2502.         return NULL;
                ^
  2503.     }
  2504. 

libavformat/utils.c:2537:1: return from a call to av_new_stream
  2535.     s->streams[s->nb_streams++] = st;
  2536.     return st;
  2537. }
        ^
  2538. 
  2539. AVProgram *av_new_program(AVFormatContext *ac, int id)

ffmpeg.c:3493:10: Taking true branch
3491. 
3492.     st = av_new_stream(oc, streamid_map[oc->nb_streams]);
3493.     if (!st) {
               ^
3494.         fprintf(stderr, "Could not alloc stream\n");
3495.         av_exit(1);

ffmpeg.c:3494:9: 
3492.     st = av_new_stream(oc, streamid_map[oc->nb_streams]);
3493.     if (!st) {
3494.         fprintf(stderr, "Could not alloc stream\n");
              ^
3495.         av_exit(1);
3496.     }

ffmpeg.c:3495:9: Skipping av_exit(): empty list of specs
3493.     if (!st) {
3494.         fprintf(stderr, "Could not alloc stream\n");
3495.         av_exit(1);
              ^
3496.     }
3497.     avcodec_get_context_defaults2(st->codec, AVMEDIA_TYPE_AUDIO);

ffmpeg.c:3497:5: 
3495.         av_exit(1);
3496.     }
3497.     avcodec_get_context_defaults2(st->codec, AVMEDIA_TYPE_AUDIO);
          ^
3498. 
3499.     bitstream_filters[nb_output_files][oc->nb_streams - 1]= audio_bitstream_filters;
