Reducing computational complexity when generating sub-pixel values for
sub-pixel motion estimation from integer pixels. In an embodiment, half
pixels in vertical and horizontal directions are computed by a applying a
filter of first complexity on integer pixels, and a half pixel in
diagonal direction is computed using a filter of lower complexity as
compared to the filter of first complexity. Quarter (and other lower
resolution pixels) pixels may also be generated using the half pixel in
the diagonal direction. Thus, overall computational complexity is reduced
in generating sub-pixels for sub-pixel motion estimation.