avconv.c:171: error: Integer Overflow L1
  ([-oo, 0] - 1):unsigned32 by call to `avformat_free_context`.

avconv.c:159:9: Call
157.         }
158.         av_freep(&fg->outputs);
159.         av_freep(&fg->graph_desc);
             ^
160. 
161.         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:171:9: Call
169.         if (s && s->oformat && !(s->oformat->flags & AVFMT_NOFILE) && s->pb)
170.             avio_close(s->pb);
171.         avformat_free_context(s);
             ^
172.         av_dict_free(&of->opts);
173. 

libavformat/utils.c:2477:1: <LHS trace>
2475. }
2476. 
2477. void avformat_free_context(AVFormatContext *s)
      ^
2478. {
2479.     int i;

libavformat/utils.c:2477:1: Parameter `s->nb_chapters`
  2475. }
  2476. 
  2477. void avformat_free_context(AVFormatContext *s)
        ^
  2478. {
  2479.     int i;

libavformat/utils.c:2498:12: Binary operation: ([-oo, 0] - 1):unsigned32 by call to `avformat_free_context` 
  2496.     av_freep(&s->programs);
  2497.     av_freep(&s->priv_data);
  2498.     while (s->nb_chapters--) {
                   ^
  2499.         av_dict_free(&s->chapters[s->nb_chapters]->metadata);
  2500.         av_free(s->chapters[s->nb_chapters]);
