avconv.c:172: error: Integer Overflow L1
  ([-oo, 0] - 1):unsigned32 by call to `avformat_free_context`.

avconv.c:160:9: Call
158.         }
159.         av_freep(&fg->outputs);
160.         av_freep(&fg->graph_desc);
             ^
161. 
162.         av_freep(&filtergraphs[i]);

libavutil/mem.c:207:26: Assignment
  205. 
  206.     memcpy(&val, arg, sizeof(val));
  207.     memcpy(arg, &(void *){ NULL }, sizeof(val));
                                ^
  208.     av_free(val);
  209. }

avconv.c:172:9: Call
170.         if (s && s->oformat && !(s->oformat->flags & AVFMT_NOFILE) && s->pb)
171.             avio_close(s->pb);
172.         avformat_free_context(s);
             ^
173.         av_dict_free(&of->opts);
174. 

libavformat/utils.c:2432:1: <LHS trace>
2430. }
2431. 
2432. void avformat_free_context(AVFormatContext *s)
      ^
2433. {
2434.     int i, j;

libavformat/utils.c:2432:1: Parameter `s->nb_chapters`
  2430. }
  2431. 
  2432. void avformat_free_context(AVFormatContext *s)
        ^
  2433. {
  2434.     int i, j;

libavformat/utils.c:2475:12: Binary operation: ([-oo, 0] - 1):unsigned32 by call to `avformat_free_context` 
  2473.     av_freep(&s->programs);
  2474.     av_freep(&s->priv_data);
  2475.     while (s->nb_chapters--) {
                   ^
  2476.         av_dict_free(&s->chapters[s->nb_chapters]->metadata);
  2477.         av_free(s->chapters[s->nb_chapters]);
