commit 766a389b58fe6979098c0e8125710dda01f8fede
author Urvang Joshi <urvang@google.com> Fri Mar 31 14:44:47 2017 -0700
committer Urvang Joshi <urvang@google.com> Tue Jun 06 16:02:38 2017 +0000
tree b44ca514c0d622a986805efd719fa2bf653ffbad
parent dac5e391af658c5d0424f60fcb1e237848fa8c97

Add a new experiment "rect-intra-pred".

Earlier, intra prediction for rectangular blocks was performed by
running two steps of prediction on square sub-blocks.

With this experiment, we do proper intra prediction for rectangular
blocks. This ensures that we make use of all available neighboring
pixels especially for directional modes. For this, all the intra
predictors were updated to work with rectangular transform block sizes.

Performance improvements are small but free of cost:

All Intra frames:
lowres: -0.126
midres: -0.154

Video Overall:
lowres: -0.043
midres: -0.100

[Could not get AWCY results due to a backlog.]

BUG=aomedia:551

Change-Id: I7936e91b171d5c246cb0a4ea470a981a013892e6