NV12 to/from I420 coalesce rows for Y and UV independently.
BUG=197
TESTED=*NV12*_Opt
Review URL: https://webrtc-codereview.appspot.com/1201004

git-svn-id: http://libyuv.googlecode.com/svn/trunk@607 16f28f9a-4ce2-e073-06de-1de4eb20be90
5 files changed