libavfilter/defaults.c:106: error: Integer Overflow L2
  ([0, +oo] - 1):unsigned32 by call to `avfilter_unref_buffer`.

libavfilter/defaults.c:106:13: Call
104.     if(out) {
105.         if(out->out_buf) {
106.             avfilter_unref_buffer(out->out_buf);
                 ^
107.             out->out_buf = NULL;
108.         }

libavfilter/avfilter.c:61:1: <LHS trace>
59. }
60. 
61. void avfilter_unref_buffer(AVFilterBufferRef *ref)
    ^
62. {
63.     if(!(--ref->buf->refcount))

libavfilter/avfilter.c:61:1: Parameter `ref->buf->refcount`
  59. }
  60. 
  61. void avfilter_unref_buffer(AVFilterBufferRef *ref)
      ^
  62. {
  63.     if(!(--ref->buf->refcount))

libavfilter/avfilter.c:63:10: Binary operation: ([0, +oo] - 1):unsigned32 by call to `avfilter_unref_buffer` 
  61. void avfilter_unref_buffer(AVFilterBufferRef *ref)
  62. {
  63.     if(!(--ref->buf->refcount))
               ^
  64.         ref->buf->free(ref->buf);
  65.     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);
}
['void avfilter_default_end_frame(AVFilterLink *link)\n{\n    AVFilterLink *out = NULL;\n    if(link->dst->output_count)\n        out = link->dst->outputs[0];\n    avfilter_unref_buffer(link->cur_buf);\n    link->cur_buf = NULL;\n    if(out) {\n        if(out->out_buf) {\n            avfilter_unref_buffer(out->out_buf);\n            out->out_buf = NULL;\n        }\n        avfilter_end_frame(out);\n    }\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);\n}']