shithub: libvpx

Download patch

ref: afee58f2c4159172f5340f2c7d3e8041cfa0eb91
parent: c39cd9235ece2e55f0cc84fb0f9f5e698146ee9c
author: Linfeng Zhang <linfengz@google.com>
date: Tue Sep 12 07:37:04 EDT 2017

Specialize 4 to 3 scaling in vp9_scale_and_extend_frame_c()

Scale 3x3 block instead of 16x16 block in each loop.

Benefits:
1. Reduced number of different phase_scaler from 16 to 3. Optimization code
   will be smaller and faster.
2. The maximum phase_scaler drifting will be reduced from 5/16 to 1/24.
   (The drifting is 1/(3*16) in each step.)

BUG=webm:1419

Change-Id: Ibb9242a629ddb03e1ff93b859bece738255e698c