ref: 348bdc0195afe33644fb15e3e007b04a2e2e8609
parent: 15afee19385524c8ea3975f6fd11fd6282c0aa15
author: Marco <marpan@google.com>
date: Thu Apr 13 13:19:06 EDT 2017
vp9: Add phase to get averaging filter for 1:2 downsampling. The scaling filter with zero shift will give sub-sampling for 2x downsampling. Allow for a phase shift to get an averaging filter. Usage is for source scaling in 1 pass SVC mode for 1:2 downscale. Reduces aliasing in downsampled image. Keep the phase to 0/off for now. Change-Id: Ic547ea0748d151b675f877527e656407fcf4d51e