commit 5a3e3c6d3fa308066e2cef1f8cbc407cd540c176
author Jingning Han <jingning@google.com> Wed Jun 25 16:53:07 2014 -0700
committer Jingning Han <jingning@google.com> Thu Jun 26 16:00:42 2014 -0700
tree 9001ca15c0cc30288a4d837b23207440fd859a9d
parent 73eeb3beffefb5238071988fbea94cba9c2b558b

Adaptive txfm size selection depending on residual sse/variance

This commit enables an adaptive transform size selection method
for speed -6. It uses largest transform size when the sse is more
than 4 times of variance, i.e., most energy is compacted in the
DC coefficient. Otherwise, use the default TX_8X8. It improves
the compression efficiency for rtc set of speed -6 by 0.8%, no
speed change observed.

Change-Id: Ie6ed1e728ff7bf88ebe940a60811361cdd19969c