libavfilter/vf_scale.c:130: error: Integer Overflow L2
  ([0, +oo] - 1):unsigned32 by call to `ff_formats_unref`.

libavfilter/vf_scale.c:129:27: Call
127.             if ((sws_isSupportedInput(pix_fmt) ||
128.                  sws_isSupportedEndiannessConversion(pix_fmt))
129.                 && (ret = ff_add_format(&formats, pix_fmt)) < 0) {
                               ^
130.                 ff_formats_unref(&formats);
131.                 return ret;

libavfilter/formats.c:199:1: Parameter `(*avff)->nb_formats`
  197. } while (0)
  198. 
  199. int ff_add_format(AVFilterFormats **avff, int fmt)
       ^
  200. {
  201.     ADD_FORMAT(avff, fmt, int, formats, nb_formats);

libavfilter/vf_scale.c:130:17: Call
128.                  sws_isSupportedEndiannessConversion(pix_fmt))
129.                 && (ret = ff_add_format(&formats, pix_fmt)) < 0) {
130.                 ff_formats_unref(&formats);
                     ^
131.                 return ret;
132.             }

libavfilter/formats.c:302:1: <LHS trace>
300. } while (0)
301. 
302. void ff_formats_unref(AVFilterFormats **ref)
     ^
303. {
304.     FORMATS_UNREF(ref, formats);

libavfilter/formats.c:302:1: Parameter `(*ref)->refcount`
  300. } while (0)
  301. 
  302. void ff_formats_unref(AVFilterFormats **ref)
       ^
  303. {
  304.     FORMATS_UNREF(ref, formats);

libavfilter/formats.c:304:5: Binary operation: ([0, +oo] - 1):unsigned32 by call to `ff_formats_unref` 
  302. void ff_formats_unref(AVFilterFormats **ref)
  303. {
  304.     FORMATS_UNREF(ref, formats);
           ^
  305. }
  306. 
