Clip1Y            403 libde265/intrapred.cc         pred[0+y*stride] = Clip1Y(border[1] + ((border[-1-y] - border[0])>>1));
Clip1Y            441 libde265/intrapred.cc         pred[x] = Clip1Y(border[-1] + ((border[1+x] - border[0])>>1)); // DIFF (x<->y && neg)