libavfilter/buffer.c:94: error: Integer Overflow L2
  ([0, +oo] - 1):unsigned32 by call to `avfilter_unref_buffer`.

libavfilter/buffer.c:94:5: Call
92. {
93. FF_DISABLE_DEPRECATION_WARNINGS
94.     avfilter_unref_buffer(*ref);
        ^
95. FF_ENABLE_DEPRECATION_WARNINGS
96.     *ref = NULL;

libavfilter/buffer.c:78:1: <LHS trace>
76. }
77. 
78. void avfilter_unref_buffer(AVFilterBufferRef *ref)
    ^
79. {
80.     if (!ref)

libavfilter/buffer.c:78:1: Parameter `ref->buf->refcount`
  76. }
  77. 
  78. void avfilter_unref_buffer(AVFilterBufferRef *ref)
      ^
  79. {
  80.     if (!ref)

libavfilter/buffer.c:82:11: Binary operation: ([0, +oo] - 1):unsigned32 by call to `avfilter_unref_buffer` 
  80.     if (!ref)
  81.         return;
  82.     if (!(--ref->buf->refcount))
                ^
  83.         ref->buf->free(ref->buf);
  84.     if (ref->extended_data != ref->data)
