libavfilter/vf_unsharp.c:205: error: Integer Overflow L2
  ([0, +oo] - 1):unsigned32 by call to `avfilter_unref_pic`.

libavfilter/vf_unsharp.c:205:5: Call
203.     unsharpen(out->data[2], in->data[2], out->linesize[2], in->linesize[2], CHROMA_WIDTH(link), CHROMA_HEIGHT(link), &unsharp->chroma);
204. 
205.     avfilter_unref_pic(in);
         ^
206.     avfilter_draw_slice(link->dst->outputs[0], 0, link->h, 1);
207.     avfilter_end_frame(link->dst->outputs[0]);

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);
}
['static void end_frame(AVFilterLink *link)\n{\n    UnsharpContext *unsharp = link->dst->priv;\n    AVFilterPicRef *in  = link->cur_pic;\n    AVFilterPicRef *out = link->dst->outputs[0]->outpic;\n    unsharpen(out->data[0], in->data[0], out->linesize[0], in->linesize[0], link->w,            link->h,             &unsharp->luma);\n    unsharpen(out->data[1], in->data[1], out->linesize[1], in->linesize[1], CHROMA_WIDTH(link), CHROMA_HEIGHT(link), &unsharp->chroma);\n    unsharpen(out->data[2], in->data[2], out->linesize[2], in->linesize[2], CHROMA_WIDTH(link), CHROMA_HEIGHT(link), &unsharp->chroma);\n    avfilter_unref_pic(in);\n    avfilter_draw_slice(link->dst->outputs[0], 0, link->h, 1);\n    avfilter_end_frame(link->dst->outputs[0]);\n    avfilter_unref_pic(out);\n}', 'void avfilter_unref_pic(AVFilterPicRef *ref)\n{\n    if(!(--ref->pic->refcount))\n        ref->pic->free(ref->pic);\n    av_free(ref);\n}']