libavcodec/vp9dsp.c:1629: error: Uninitialized Value
  The value read from flat8in was never initialized.

libavcodec/vp9dsp.c:1629:31: 
1627.             dst[strideb * +6] = (p0 + q0 + q1 + q2 + q3 + q4 + q5 + q6 * 2 +
1628.                                  q7 + q7 + q7 + q7 + q7 + q7 + q7 + 8) >> 4;
1629.         } else if (wd >= 8 && flat8in) {
                                    ^
1630.             dst[strideb * -3] = (p3 + p3 + p3 + 2 * p2 + p1 + p0 + q0 + 4) >> 3;
1631.             dst[strideb * -2] = (p3 + p3 + p2 + 2 * p1 + p0 + q0 + q1 + 4) >> 3;
