When interpolating, weights are based on relative distances, which
assume square pixels. If a non-1:1 sample aspect ratio is used, it
should be taken into account when comparing distances, because the
human eye and brain care about the picture as it is displayed, not
stored.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>