ref: 4d8958d8dddb9104e006bc806a2607bd4ee71708
parent: 6cc33c1626028df5f504a9cf47d42d68a2fc9b1c
author: Marco Paniconi <marpan@google.com>
date: Thu Mar 1 04:45:11 EST 2018
vp9-svc: Fix to downsampling filter phase_shift. Set phase_shift = 0 if the scale factors are above 3/4. Removes artifact for scale factors close to 1. phase_shift = 8 is to get an averaging filter (decimated pixel aligns to 8/16, midway between source pixels), and only makes sense for scale factors multiples of 2 (1/2, 1/4,...). Removes artifact for high scaling ratios. Change-Id: Id0a85869d6c6156dda0032c697ded2de78fad6bd