avconv.c:2013: error: Integer Overflow L2
  ([0, +oo] - 1):unsigned32 by call to `avfilter_unref_buffer`.

avconv.c:2009:17: Call
2007.                          same_quant ? quality : ost->st->codec->global_quality);
2008.             if (vstats_filename && frame_size)
2009.                 do_video_stats(output_files[ost->file_index].ctx, ost, frame_size);
                      ^
2010. #if CONFIG_AVFILTER
2011.             frame_available = ost->output_video_filter && avfilter_poll_frame(ost->output_video_filter->inputs[0]);

avconv.c:2013:17: Call
2011.             frame_available = ost->output_video_filter && avfilter_poll_frame(ost->output_video_filter->inputs[0]);
2012.             if (ost->picref)
2013.                 avfilter_unref_buffer(ost->picref);
                      ^
2014.         }
2015. #endif

libavfilter/avfilter.c:73:1: <LHS trace>
71. }
72. 
73. void avfilter_unref_buffer(AVFilterBufferRef *ref)
    ^
74. {
75.     if (!ref)

libavfilter/avfilter.c:73:1: Parameter `ref->buf->refcount`
  71. }
  72. 
  73. void avfilter_unref_buffer(AVFilterBufferRef *ref)
      ^
  74. {
  75.     if (!ref)

libavfilter/avfilter.c:77:11: Binary operation: ([0, +oo] - 1):unsigned32 by call to `avfilter_unref_buffer` 
  75.     if (!ref)
  76.         return;
  77.     if (!(--ref->buf->refcount))
                ^
  78.         ref->buf->free(ref->buf);
  79.     av_free(ref->video);
