avconv.c:173: error: Integer Overflow L1
  ([-oo, 0] - 1):unsigned32 by call to `avformat_free_context`.

avconv.c:163:9: Call
161.         }
162.         av_freep(&filtergraphs[i]->outputs);
163.         av_freep(&filtergraphs[i]->graph_desc);
             ^
164.         av_freep(&filtergraphs[i]);
165.     }

libavutil/mem.c:155:5: Assignment
  153.     void **ptr = (void **)arg;
  154.     av_free(*ptr);
  155.     *ptr = NULL;
           ^
  156. }
  157. 

avconv.c:173:9: Call
171.         if (!(s->oformat->flags & AVFMT_NOFILE) && s->pb)
172.             avio_close(s->pb);
173.         avformat_free_context(s);
             ^
174.         av_dict_free(&output_files[i]->opts);
175.         av_freep(&output_files[i]);

libavformat/utils.c:2635:1: <LHS trace>
2633. }
2634. 
2635. void avformat_free_context(AVFormatContext *s)
      ^
2636. {
2637.     int i;

libavformat/utils.c:2635:1: Parameter `s->nb_chapters`
  2633. }
  2634. 
  2635. void avformat_free_context(AVFormatContext *s)
        ^
  2636. {
  2637.     int i;

libavformat/utils.c:2669:11: Binary operation: ([-oo, 0] - 1):unsigned32 by call to `avformat_free_context` 
  2667.     av_freep(&s->programs);
  2668.     av_freep(&s->priv_data);
  2669.     while(s->nb_chapters--) {
                  ^
  2670.         av_dict_free(&s->chapters[s->nb_chapters]->metadata);
  2671.         av_free(s->chapters[s->nb_chapters]);
