ref: 5daef90efc4613efd7e7ee80ba4e1ecf9a57a966
parent: 0c4a4225ec91d4db1d3b9e0b2b919ebeec60ec57
author: Pengchong Jin <pengchong@google.com>
date: Tue Jun 3 13:16:00 EDT 2014
skip un-neccessary motion search in the first pass This patch allows the encoder to skip the un-neccessary motion search in the first pass. It calculates the error of the zero motion vector using the last source frame as reference and skips the further motion search in the first pass if the error is small. The encoding speedup of the first pass for slideshow videos is over 30%. Borg test shows the overall PSNR performance remain approximately the same (derf -0.009, hd 0.387, yt 0.021, stdhd 0.065). Individual clips may have either PSNR gain or loss. The worst PSNR perfomance is from yt set, with a PSNR loss of -1.1. Change-Id: I08b2ab110b695e4689573b2567fa531b6457616e