Use bottom and right blocks' mv for referencing

This commit enables the motion vector referencing system to use
the motion information of blocks to the bottom and right of the
collocated block. This improves the compression performance by
0.3% for lowres, midres, and hdres sets.

Change-Id: I03b3fb21f3a8698880ca9ceb945fa3e32531acdb
1 file changed