avconv.c:3437: error: Null Dereference
  pointer `st` last assigned on line 3423 could be null and is dereferenced at line 3437, column 9.

avconv.c:3420:1: start of procedure new_output_stream()
3418. }
3419. 
3420. static OutputStream *new_output_stream(OptionsContext *o, AVFormatContext *oc, enum AVMediaType type)
      ^
3421. {
3422.     OutputStream *ost;

avconv.c:3423:5: 
3421. {
3422.     OutputStream *ost;
3423.     AVStream *st = avformat_new_stream(oc, NULL);
          ^
3424.     int idx      = oc->nb_streams - 1, ret = 0;
3425.     char *bsf = NULL, *next, *codec_tag = NULL;

libavformat/utils.c:2742:1: start of procedure avformat_new_stream()
  2740. #endif
  2741. 
  2742. AVStream *avformat_new_stream(AVFormatContext *s, AVCodec *c)
        ^
  2743. {
  2744.     AVStream *st;

libavformat/utils.c:2748:9: Taking true branch
  2746.     AVStream **streams;
  2747. 
  2748.     if (s->nb_streams >= INT_MAX/sizeof(*streams))
                ^
  2749.         return NULL;
  2750.     streams = av_realloc(s->streams, (s->nb_streams + 1) * sizeof(*streams));

libavformat/utils.c:2749:9: 
  2747. 
  2748.     if (s->nb_streams >= INT_MAX/sizeof(*streams))
  2749.         return NULL;
                ^
  2750.     streams = av_realloc(s->streams, (s->nb_streams + 1) * sizeof(*streams));
  2751.     if (!streams)

libavformat/utils.c:2790:1: return from a call to avformat_new_stream
  2788.     s->streams[s->nb_streams++] = st;
  2789.     return st;
  2790. }
        ^
  2791. 
  2792. AVProgram *av_new_program(AVFormatContext *ac, int id)

avconv.c:3424:5: 
3422.     OutputStream *ost;
3423.     AVStream *st = avformat_new_stream(oc, NULL);
3424.     int idx      = oc->nb_streams - 1, ret = 0;
          ^
3425.     char *bsf = NULL, *next, *codec_tag = NULL;
3426.     AVBitStreamFilterContext *bsfc, *bsfc_prev = NULL;

avconv.c:3425:5: 
3423.     AVStream *st = avformat_new_stream(oc, NULL);
3424.     int idx      = oc->nb_streams - 1, ret = 0;
3425.     char *bsf = NULL, *next, *codec_tag = NULL;
          ^
3426.     AVBitStreamFilterContext *bsfc, *bsfc_prev = NULL;
3427.     double qscale = -1;

avconv.c:3426:5: 
3424.     int idx      = oc->nb_streams - 1, ret = 0;
3425.     char *bsf = NULL, *next, *codec_tag = NULL;
3426.     AVBitStreamFilterContext *bsfc, *bsfc_prev = NULL;
          ^
3427.     double qscale = -1;
3428.     char *buf = NULL, *arg = NULL, *preset = NULL;

avconv.c:3427:5: 
3425.     char *bsf = NULL, *next, *codec_tag = NULL;
3426.     AVBitStreamFilterContext *bsfc, *bsfc_prev = NULL;
3427.     double qscale = -1;
          ^
3428.     char *buf = NULL, *arg = NULL, *preset = NULL;
3429.     AVIOContext *s = NULL;

avconv.c:3428:5: 
3426.     AVBitStreamFilterContext *bsfc, *bsfc_prev = NULL;
3427.     double qscale = -1;
3428.     char *buf = NULL, *arg = NULL, *preset = NULL;
          ^
3429.     AVIOContext *s = NULL;
3430. 

avconv.c:3429:5: 
3427.     double qscale = -1;
3428.     char *buf = NULL, *arg = NULL, *preset = NULL;
3429.     AVIOContext *s = NULL;
          ^
3430. 
3431.     if (!st) {

avconv.c:3431:10: Taking true branch
3429.     AVIOContext *s = NULL;
3430. 
3431.     if (!st) {
               ^
3432.         av_log(NULL, AV_LOG_FATAL, "Could not alloc stream.\n");
3433.         exit_program(1);

avconv.c:3432:9: Skipping av_log(): empty list of specs
3430. 
3431.     if (!st) {
3432.         av_log(NULL, AV_LOG_FATAL, "Could not alloc stream.\n");
              ^
3433.         exit_program(1);
3434.     }

avconv.c:3433:9: Skipping exit_program(): empty list of specs
3431.     if (!st) {
3432.         av_log(NULL, AV_LOG_FATAL, "Could not alloc stream.\n");
3433.         exit_program(1);
              ^
3434.     }
3435. 

avconv.c:3436:9: Taking true branch
3434.     }
3435. 
3436.     if (oc->nb_streams - 1 < o->nb_streamid_map)
              ^
3437.         st->id = o->streamid_map[oc->nb_streams - 1];
3438. 

avconv.c:3437:9: 
3435. 
3436.     if (oc->nb_streams - 1 < o->nb_streamid_map)
3437.         st->id = o->streamid_map[oc->nb_streams - 1];
              ^
3438. 
3439.     output_streams = grow_array(output_streams, sizeof(*output_streams), &nb_output_streams,
