libavfilter/defaults.c:108: error: Integer Overflow L2
  ([0, +oo] - 1):unsigned32 by call to `avfilter_unref_pic`.

libavfilter/defaults.c:108:13: Call
106.     if(out) {
107.         if(out->outpic) {
108.             avfilter_unref_pic(out->outpic);
                 ^
109.             out->outpic = NULL;
110.         }

libavfilter/avfilter.c:56:1: <LHS trace>
54. }
55. 
56. void avfilter_unref_pic(AVFilterPicRef *ref)
    ^
57. {
58.     if(!(--ref->pic->refcount))

libavfilter/avfilter.c:56:1: Parameter `ref->pic->refcount`
  54. }
  55. 
  56. void avfilter_unref_pic(AVFilterPicRef *ref)
      ^
  57. {
  58.     if(!(--ref->pic->refcount))

libavfilter/avfilter.c:58:10: Binary operation: ([0, +oo] - 1):unsigned32 by call to `avfilter_unref_pic` 
  56. void avfilter_unref_pic(AVFilterPicRef *ref)
  57. {
  58.     if(!(--ref->pic->refcount))
               ^
  59.         ref->pic->free(ref->pic);
  60.     av_free(ref);

void avfilter_unref_pic(AVFilterPicRef *ref)
{
    if(!(--ref->pic->refcount))
        ref->pic->free(ref->pic);
    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_pic(link->cur_pic);\n    link->cur_pic = NULL;\n    if(out) {\n        if(out->outpic) {\n            avfilter_unref_pic(out->outpic);\n            out->outpic = NULL;\n        }\n        avfilter_end_frame(out);\n    }\n}', 'void avfilter_unref_pic(AVFilterPicRef *ref)\n{\n    if(!(--ref->pic->refcount))\n        ref->pic->free(ref->pic);\n    av_free(ref);\n}']