libavfilter/avfilter.c:292: error: Integer Overflow L2
  ([0, +oo] - 1):unsigned32 by call to `avfilter_unref_buffer`.

libavfilter/avfilter.c:292:9: Call
290.      * a copied version dues to permission issues */
291.     if(link->src_buf) {
292.         avfilter_unref_buffer(link->src_buf);
             ^
293.         link->src_buf = NULL;
294.     }

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_end_frame(AVFilterLink *link)\n{\n    void (*end_frame)(AVFilterLink *);\n    if(!(end_frame = link_dpad(link).end_frame))\n        end_frame = avfilter_default_end_frame;\n    end_frame(link);\n    if(link->src_buf) {\n        avfilter_unref_buffer(link->src_buf);\n        link->src_buf = NULL;\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}']