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;

static void new_subtitle_stream(AVFormatContext *oc)
{
    AVStream *st;
    AVCodecContext *subtitle_enc;
    st = av_new_stream(oc, streamid_map[oc->nb_streams]);
    if (!st) {
        fprintf(stderr, "Could not alloc stream\n");
        ffmpeg_exit(1);
    }
    avcodec_get_context_defaults2(st->codec, AVMEDIA_TYPE_SUBTITLE);
    bitstream_filters[nb_output_files][oc->nb_streams - 1]= subtitle_bitstream_filters;
    subtitle_bitstream_filters= NULL;
    subtitle_enc = st->codec;
    subtitle_enc->codec_type = AVMEDIA_TYPE_SUBTITLE;
    if(subtitle_codec_tag)
        subtitle_enc->codec_tag= subtitle_codec_tag;
    if (subtitle_stream_copy) {
        st->stream_copy = 1;
    } else {
        set_context_opts(avcodec_opts[AVMEDIA_TYPE_SUBTITLE], subtitle_enc, AV_OPT_FLAG_SUBTITLE_PARAM | AV_OPT_FLAG_ENCODING_PARAM);
        subtitle_enc->codec_id = find_codec_or_die(subtitle_codec_name, AVMEDIA_TYPE_SUBTITLE, 1,
                                                   subtitle_enc->strict_std_compliance);
        output_codecs[nb_ocodecs] = avcodec_find_encoder_by_name(subtitle_codec_name);
    }
    nb_ocodecs++;
    if (subtitle_language) {
        av_metadata_set2(&st->metadata, "language", subtitle_language, 0);
        av_freep(&subtitle_language);
    }
    subtitle_disable = 0;
    av_freep(&subtitle_codec_name);
    subtitle_stream_copy = 0;
}
['static void new_subtitle_stream(AVFormatContext *oc)\n{\n    AVStream *st;\n    AVCodecContext *subtitle_enc;\n    st = av_new_stream(oc, streamid_map[oc->nb_streams]);\n    if (!st) {\n        fprintf(stderr, "Could not alloc stream\\n");\n        ffmpeg_exit(1);\n    }\n    avcodec_get_context_defaults2(st->codec, AVMEDIA_TYPE_SUBTITLE);\n    bitstream_filters[nb_output_files][oc->nb_streams - 1]= subtitle_bitstream_filters;\n    subtitle_bitstream_filters= NULL;\n    subtitle_enc = st->codec;\n    subtitle_enc->codec_type = AVMEDIA_TYPE_SUBTITLE;\n    if(subtitle_codec_tag)\n        subtitle_enc->codec_tag= subtitle_codec_tag;\n    if (subtitle_stream_copy) {\n        st->stream_copy = 1;\n    } else {\n        set_context_opts(avcodec_opts[AVMEDIA_TYPE_SUBTITLE], subtitle_enc, AV_OPT_FLAG_SUBTITLE_PARAM | AV_OPT_FLAG_ENCODING_PARAM);\n        subtitle_enc->codec_id = find_codec_or_die(subtitle_codec_name, AVMEDIA_TYPE_SUBTITLE, 1,\n                                                   subtitle_enc->strict_std_compliance);\n        output_codecs[nb_ocodecs] = avcodec_find_encoder_by_name(subtitle_codec_name);\n    }\n    nb_ocodecs++;\n    if (subtitle_language) {\n        av_metadata_set2(&st->metadata, "language", subtitle_language, 0);\n        av_freep(&subtitle_language);\n    }\n    subtitle_disable = 0;\n    av_freep(&subtitle_codec_name);\n    subtitle_stream_copy = 0;\n}', 'AVStream *av_new_stream(AVFormatContext *s, int id)\n{\n    AVStream *st;\n    int i;\n    if (s->nb_streams >= MAX_STREAMS){\n        av_log(s, AV_LOG_ERROR, "Too many streams\\n");\n        return NULL;\n    }\n    st = av_mallocz(sizeof(AVStream));\n    if (!st)\n        return NULL;\n    st->codec= avcodec_alloc_context();\n    if (s->iformat) {\n        st->codec->bit_rate = 0;\n    }\n    st->index = s->nb_streams;\n    st->id = id;\n    st->start_time = AV_NOPTS_VALUE;\n    st->duration = AV_NOPTS_VALUE;\n    st->cur_dts = 0;\n    st->first_dts = AV_NOPTS_VALUE;\n    st->probe_packets = MAX_PROBE_PACKETS;\n    av_set_pts_info(st, 33, 1, 90000);\n    st->last_IP_pts = AV_NOPTS_VALUE;\n    for(i=0; i<MAX_REORDER_DELAY+1; i++)\n        st->pts_buffer[i]= AV_NOPTS_VALUE;\n    st->reference_dts = AV_NOPTS_VALUE;\n    st->sample_aspect_ratio = (AVRational){0,1};\n    s->streams[s->nb_streams++] = st;\n    return st;\n}']