avconv.c:3173: error: Null Dereference
  pointer `st` last assigned on line 3159 could be null and is dereferenced at line 3173, column 9.

avconv.c:3156:1: start of procedure new_output_stream()
3154. }
3155. 
3156. static OutputStream *new_output_stream(OptionsContext *o, AVFormatContext *oc, enum AVMediaType type)
      ^
3157. {
3158.     OutputStream *ost;

avconv.c:3159:5: 
3157. {
3158.     OutputStream *ost;
3159.     AVStream *st = avformat_new_stream(oc, NULL);
          ^
3160.     int idx      = oc->nb_streams - 1, ret = 0;
3161.     char *bsf = NULL, *next, *codec_tag = NULL;

libavformat/utils.c:2705:1: start of procedure avformat_new_stream()
  2703. #endif
  2704. 
  2705. AVStream *avformat_new_stream(AVFormatContext *s, AVCodec *c)
        ^
  2706. {
  2707.     AVStream *st;

libavformat/utils.c:2711:9: Taking true branch
  2709.     AVStream **streams;
  2710. 
  2711.     if (s->nb_streams >= INT_MAX/sizeof(*streams))
                ^
  2712.         return NULL;
  2713.     streams = av_realloc(s->streams, (s->nb_streams + 1) * sizeof(*streams));

libavformat/utils.c:2712:9: 
  2710. 
  2711.     if (s->nb_streams >= INT_MAX/sizeof(*streams))
  2712.         return NULL;
                ^
  2713.     streams = av_realloc(s->streams, (s->nb_streams + 1) * sizeof(*streams));
  2714.     if (!streams)

libavformat/utils.c:2753:1: return from a call to avformat_new_stream
  2751.     s->streams[s->nb_streams++] = st;
  2752.     return st;
  2753. }
        ^
  2754. 
  2755. AVProgram *av_new_program(AVFormatContext *ac, int id)

avconv.c:3160:5: 
3158.     OutputStream *ost;
3159.     AVStream *st = avformat_new_stream(oc, NULL);
3160.     int idx      = oc->nb_streams - 1, ret = 0;
          ^
3161.     char *bsf = NULL, *next, *codec_tag = NULL;
3162.     AVBitStreamFilterContext *bsfc, *bsfc_prev = NULL;

avconv.c:3161:5: 
3159.     AVStream *st = avformat_new_stream(oc, NULL);
3160.     int idx      = oc->nb_streams - 1, ret = 0;
3161.     char *bsf = NULL, *next, *codec_tag = NULL;
          ^
3162.     AVBitStreamFilterContext *bsfc, *bsfc_prev = NULL;
3163.     double qscale = -1;

avconv.c:3162:5: 
3160.     int idx      = oc->nb_streams - 1, ret = 0;
3161.     char *bsf = NULL, *next, *codec_tag = NULL;
3162.     AVBitStreamFilterContext *bsfc, *bsfc_prev = NULL;
          ^
3163.     double qscale = -1;
3164.     char *buf = NULL, *arg = NULL, *preset = NULL;

avconv.c:3163:5: 
3161.     char *bsf = NULL, *next, *codec_tag = NULL;
3162.     AVBitStreamFilterContext *bsfc, *bsfc_prev = NULL;
3163.     double qscale = -1;
          ^
3164.     char *buf = NULL, *arg = NULL, *preset = NULL;
3165.     AVIOContext *s = NULL;

avconv.c:3164:5: 
3162.     AVBitStreamFilterContext *bsfc, *bsfc_prev = NULL;
3163.     double qscale = -1;
3164.     char *buf = NULL, *arg = NULL, *preset = NULL;
          ^
3165.     AVIOContext *s = NULL;
3166. 

avconv.c:3165:5: 
3163.     double qscale = -1;
3164.     char *buf = NULL, *arg = NULL, *preset = NULL;
3165.     AVIOContext *s = NULL;
          ^
3166. 
3167.     if (!st) {

avconv.c:3167:10: Taking true branch
3165.     AVIOContext *s = NULL;
3166. 
3167.     if (!st) {
               ^
3168.         av_log(NULL, AV_LOG_FATAL, "Could not alloc stream.\n");
3169.         exit_program(1);

avconv.c:3168:9: Skipping av_log(): empty list of specs
3166. 
3167.     if (!st) {
3168.         av_log(NULL, AV_LOG_FATAL, "Could not alloc stream.\n");
              ^
3169.         exit_program(1);
3170.     }

avconv.c:3169:9: Skipping exit_program(): empty list of specs
3167.     if (!st) {
3168.         av_log(NULL, AV_LOG_FATAL, "Could not alloc stream.\n");
3169.         exit_program(1);
              ^
3170.     }
3171. 

avconv.c:3172:9: Taking true branch
3170.     }
3171. 
3172.     if (oc->nb_streams - 1 < o->nb_streamid_map)
              ^
3173.         st->id = o->streamid_map[oc->nb_streams - 1];
3174. 

avconv.c:3173:9: 
3171. 
3172.     if (oc->nb_streams - 1 < o->nb_streamid_map)
3173.         st->id = o->streamid_map[oc->nb_streams - 1];
              ^
3174. 
3175.     output_streams = grow_array(output_streams, sizeof(*output_streams), &nb_output_streams,
