libavfilter/avfiltergraph.c:557: error: Integer Overflow L2
  ([0, +oo] - 1):unsigned32 by call to `pick_format`.

libavfilter/avfiltergraph.c:557:24: Call
555. 
556.         for (j = 0; j < filter->nb_inputs; j++)
557.             if ((ret = pick_format(filter->inputs[j])) < 0)
                            ^
558.                 return ret;
559.         for (j = 0; j < filter->nb_outputs; j++)

libavfilter/avfiltergraph.c:282:1: Parameter `link->out_samplerates->refcount`
  280. }
  281. 
  282. static int pick_format(AVFilterLink *link)
       ^
  283. {
  284.     if (!link || !link->in_formats)

libavfilter/avfiltergraph.c:557:24: Call
555. 
556.         for (j = 0; j < filter->nb_inputs; j++)
557.             if ((ret = pick_format(filter->inputs[j])) < 0)
                            ^
558.                 return ret;
559.         for (j = 0; j < filter->nb_outputs; j++)

libavfilter/avfiltergraph.c:282:1: Parameter `link->in_formats->refcount`
  280. }
  281. 
  282. static int pick_format(AVFilterLink *link)
       ^
  283. {
  284.     if (!link || !link->in_formats)

libavfilter/avfiltergraph.c:310:5: Call
  308.     }
  309. 
  310.     ff_formats_unref(&link->in_formats);
           ^
  311.     ff_formats_unref(&link->out_formats);
  312.     ff_formats_unref(&link->in_samplerates);

libavfilter/formats.c:295:1: <LHS trace>
293. } while (0)
294. 
295. void ff_formats_unref(AVFilterFormats **ref)
     ^
296. {
297.     FORMATS_UNREF(ref, formats);

libavfilter/formats.c:295:1: Parameter `(*ref)->refcount`
    293. } while (0)
    294. 
    295. void ff_formats_unref(AVFilterFormats **ref)
         ^
    296. {
    297.     FORMATS_UNREF(ref, formats);

libavfilter/formats.c:297:5: Binary operation: ([0, +oo] - 1):unsigned32 by call to `pick_format` 
    295. void ff_formats_unref(AVFilterFormats **ref)
    296. {
    297.     FORMATS_UNREF(ref, formats);
             ^
    298. }
    299. 
