avconv.c:171: error: Integer Overflow L2
  ([0, +oo] - 1):unsigned32 by call to `avformat_free_context`.

avconv.c:161:9: Call
159.             av_freep(&filtergraphs[i]->outputs[j]);
160.         }
161.         av_freep(&filtergraphs[i]->outputs);
             ^
162.         av_freep(&filtergraphs[i]);
163.     }

libavutil/mem.c:158:5: Assignment
  156.     void **ptr = (void **)arg;
  157.     av_free(*ptr);
  158.     *ptr = NULL;
           ^
  159. }
  160. 

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

libavformat/utils.c:2623:1: <LHS trace>
2621. }
2622. 
2623. void avformat_free_context(AVFormatContext *s)
      ^
2624. {
2625.     int i;

libavformat/utils.c:2623:1: Parameter `s->nb_programs`
  2621. }
  2622. 
  2623. void avformat_free_context(AVFormatContext *s)
        ^
  2624. {
  2625.     int i;

libavformat/utils.c:2649:9: Binary operation: ([0, +oo] - 1):unsigned32 by call to `avformat_free_context` 
  2647.         av_free(st);
  2648.     }
  2649.     for(i=s->nb_programs-1; i>=0; i--) {
                ^
  2650.         av_dict_free(&s->programs[i]->metadata);
  2651.         av_freep(&s->programs[i]->stream_index);
