tree fb88489b82fb17853ebebbe101cb8d5f2d981f9f
parent 487958074a745f956f3c66d43ffeac36bc9c120c
author Jingning Han <jingning@google.com> 1508958150 -0700
committer Jingning Han <jingning@google.com> 1509388046 +0000

Speed up inter frame rate-distortion optimization

The frame marker system supports one to map the reference frame
index into the natural order. It allows direct checking on the
efficacy of the reference frames given their relative locations
with respect to the current coding frame.

This commit uses such property to filter out reference frames
less likely to contribute coding gains from the rate-distortion
optimization process. For example, it takes out the check on
last2 / 3 frames, when their actual location is further away
from the golden frame.

The AWCY results show 0.6% performance regression. The encoding
speed gets doubled.

To use the speed up, one needs to turn on frame-marker experiment
before we turn it on by default, and enable selective_ref_frame
entry in the speed feature.

Change-Id: Ifb03ed90acd980bbc7ff1c2e17982e21e68d2588