ffmpeg.c:3170: error: Null Dereference
  pointer `st` last assigned on line 3165 could be null and is dereferenced at line 3170, column 35.

ffmpeg.c:3160:1: start of procedure new_subtitle_stream()
3158. }
3159. 
3160. static void new_subtitle_stream(AVFormatContext *oc)
      ^
3161. {
3162.     AVStream *st;

ffmpeg.c:3165:5: 
3163.     AVCodecContext *subtitle_enc;
3164. 
3165.     st = av_new_stream(oc, oc->nb_streams);
          ^
3166.     if (!st) {
3167.         fprintf(stderr, "Could not alloc stream\n");

libavformat/utils.c:2319:1: start of procedure av_new_stream()
  2317. }
  2318. 
  2319. AVStream *av_new_stream(AVFormatContext *s, int id)
        ^
  2320. {
  2321.     AVStream *st;

libavformat/utils.c:2324:9: Taking true branch
  2322.     int i;
  2323. 
  2324.     if (s->nb_streams >= MAX_STREAMS)
                ^
  2325.         return NULL;
  2326. 

libavformat/utils.c:2325:9: 
  2323. 
  2324.     if (s->nb_streams >= MAX_STREAMS)
  2325.         return NULL;
                ^
  2326. 
  2327.     st = av_mallocz(sizeof(AVStream));

libavformat/utils.c:2357:1: return from a call to av_new_stream
  2355.     s->streams[s->nb_streams++] = st;
  2356.     return st;
  2357. }
        ^
  2358. 
  2359. AVProgram *av_new_program(AVFormatContext *ac, int id)

ffmpeg.c:3166:10: Taking true branch
3164. 
3165.     st = av_new_stream(oc, oc->nb_streams);
3166.     if (!st) {
               ^
3167.         fprintf(stderr, "Could not alloc stream\n");
3168.         av_exit(1);

ffmpeg.c:3167:9: 
3165.     st = av_new_stream(oc, oc->nb_streams);
3166.     if (!st) {
3167.         fprintf(stderr, "Could not alloc stream\n");
              ^
3168.         av_exit(1);
3169.     }

ffmpeg.c:3168:9: Skipping av_exit(): empty list of specs
3166.     if (!st) {
3167.         fprintf(stderr, "Could not alloc stream\n");
3168.         av_exit(1);
              ^
3169.     }
3170.     avcodec_get_context_defaults2(st->codec, CODEC_TYPE_SUBTITLE);

ffmpeg.c:3170:5: 
3168.         av_exit(1);
3169.     }
3170.     avcodec_get_context_defaults2(st->codec, CODEC_TYPE_SUBTITLE);
          ^
3171. 
3172.     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, oc->nb_streams);
    if (!st) {
        fprintf(stderr, "Could not alloc stream\n");
        av_exit(1);
    }
    avcodec_get_context_defaults2(st->codec, CODEC_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 = CODEC_TYPE_SUBTITLE;
    if (subtitle_stream_copy) {
        st->stream_copy = 1;
    } else {
        set_context_opts(avctx_opts[CODEC_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, CODEC_TYPE_SUBTITLE, 1);
        output_codecs[nb_ocodecs] = avcodec_find_encoder_by_name(subtitle_codec_name);
    }
    nb_ocodecs++;
    if (subtitle_language) {
        av_strlcpy(st->language, subtitle_language, sizeof(st->language));
        av_free(subtitle_language);
        subtitle_language = NULL;
    }
    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, oc->nb_streams);\n    if (!st) {\n        fprintf(stderr, "Could not alloc stream\\n");\n        av_exit(1);\n    }\n    avcodec_get_context_defaults2(st->codec, CODEC_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 = CODEC_TYPE_SUBTITLE;\n    if (subtitle_stream_copy) {\n        st->stream_copy = 1;\n    } else {\n        set_context_opts(avctx_opts[CODEC_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, CODEC_TYPE_SUBTITLE, 1);\n        output_codecs[nb_ocodecs] = avcodec_find_encoder_by_name(subtitle_codec_name);\n    }\n    nb_ocodecs++;\n    if (subtitle_language) {\n        av_strlcpy(st->language, subtitle_language, sizeof(st->language));\n        av_free(subtitle_language);\n        subtitle_language = NULL;\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        return NULL;\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    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->sample_aspect_ratio = (AVRational){0,1};\n    s->streams[s->nb_streams++] = st;\n    return st;\n}']