avconv.c:1890: error: Integer Overflow L2
  ([0, +oo] - 1):unsigned32 by call to `avfilter_unref_buffer`.

avconv.c:1879:17: Call
1877.                     ost->st->codec->sample_aspect_ratio = picref->video->pixel_aspect;
1878. 
1879.                 do_video_out(of->ctx, ost, filtered_frame, &frame_size,
                      ^
1880.                              same_quant ? ost->last_quality :
1881.                                           ost->st->codec->global_quality);

avconv.c:1744:13: Call
  1742.             pkt.flags |= AV_PKT_FLAG_KEY;
  1743. 
  1744.             write_frame(s, &pkt, ost);
                    ^
  1745.         } else {
  1746.             int got_packet;

avconv.c:1890:13: Call
1888.             }
1889. 
1890.             avfilter_unref_buffer(picref);
                  ^
1891.         }
1892.     }

libavfilter/avfilter.c:87:1: <LHS trace>
85. }
86. 
87. void avfilter_unref_buffer(AVFilterBufferRef *ref)
    ^
88. {
89.     if (!ref)

libavfilter/avfilter.c:87:1: Parameter `ref->buf->refcount`
  85. }
  86. 
  87. void avfilter_unref_buffer(AVFilterBufferRef *ref)
      ^
  88. {
  89.     if (!ref)

libavfilter/avfilter.c:91:11: Binary operation: ([0, +oo] - 1):unsigned32 by call to `avfilter_unref_buffer` 
  89.     if (!ref)
  90.         return;
  91.     if (!(--ref->buf->refcount))
                ^
  92.         ref->buf->free(ref->buf);
  93.     if (ref->extended_data != ref->data)
