ref: ccba289f8d1760a45b972685a64eb829529b70ab
parent: 5556d1184169168e59656863456c88c3f958ca45
author: Jingning Han <jingning@google.com>
date: Thu May 29 14:14:17 EDT 2014
Fast computation path for forward transform and quantization This commit enables a fast path computational flow for forward transformation. It checks the sse and variance of prediction residuals and decides if the quantized coefficients are all zero, dc only, or more. It then selects the corresponding coding path in the forward transformation and quantization stage. It is currently enabled in rtc coding mode. Will do it for rd coding mode next. In speed -6, the runtime for pedestrian_area 1080p at 1000 kbps goes down from 14234 ms to 13704 ms, i.e., about 4% speed-up. Overall coding performance for rtc set is changed by -0.18%. Change-Id: I0452da1786d59bc8bcbe0a35fdae9f623d1d44e1