ref: e4aac6bb61cba7ab387a959c82b292ead6eba758
parent: b1b6fd85db40601485d17d5f7991d2273d8d7f05
author: Yunqing Wang <yunqingwang@google.com>
date: Wed Oct 1 07:31:34 EDT 2014
Modify block transform skipping check Block transform skipping was implemented based on DCT's energy conservation property. Modified the thresholds using zero bin parameters. AC and DC coefficients were checked separately to allow better identifying of skippable blocks. Borg test at speed 3 showed: stdhd set: psnr gain: 0.153%, ssim gain: 0.051%; derf set: psnr gain: 0.023%, ssim gain: 0.036% For most test clips, the encoding speedup is 1% - 2%. parkrun(720p): 7.5% speedup, park_joy(1080p): 3.5% speedup. Change-Id: If28eb81113a077414f5ca7b021c14f9069b373bb