avconv.c:1799: error: Integer Overflow L2
  ([0, +oo] - 1):unsigned32 by call to `avfilter_unref_buffer`.

avconv.c:1789:13: Call
1787.                 break;
1788. 
1789.             avfilter_copy_buf_props(filtered_frame, picref);
                  ^
1790.             if (picref->pts != AV_NOPTS_VALUE)
1791.                 filtered_frame->pts = av_rescale_q(picref->pts,

libavfilter/buffer.c:113:1: Parameter `dst->width`
  111. }
  112. 
  113. int avfilter_copy_buf_props(AVFrame *dst, const AVFilterBufferRef *src)
       ^
  114. {
  115.     int planes, nb_channels;

avconv.c:1799:17: Call
1797. 
1798.             if (of->start_time && filtered_frame->pts < of->start_time) {
1799.                 avfilter_unref_buffer(picref);
                      ^
1800.                 continue;
1801.             }

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

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

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