libavfilter/vf_pad.c:266: error: Integer Overflow L2
  ([0, +oo] - 1):unsigned32 by call to `avfilter_unref_buffer`.

libavfilter/vf_pad.c:266:5: Call
264. {
265.     avfilter_end_frame(link->dst->outputs[0]);
266.     avfilter_unref_buffer(link->cur_buf);
         ^
267. }
268. 

libavfilter/avfilter.c:75:1: <LHS trace>
73. }
74. 
75. void avfilter_unref_buffer(AVFilterBufferRef *ref)
    ^
76. {
77.     if (!(--ref->buf->refcount))

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

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

void avfilter_unref_buffer(AVFilterBufferRef *ref)
{
    if (!(--ref->buf->refcount))
        ref->buf->free(ref->buf);
    av_free(ref->video);
    av_free(ref->audio);
    av_free(ref);
}
['static void end_frame(AVFilterLink *link)\n{\n    avfilter_end_frame(link->dst->outputs[0]);\n    avfilter_unref_buffer(link->cur_buf);\n}', 'void avfilter_unref_buffer(AVFilterBufferRef *ref)\n{\n    if (!(--ref->buf->refcount))\n        ref->buf->free(ref->buf);\n    av_free(ref->video);\n    av_free(ref->audio);\n    av_free(ref);\n}']