commit 60456083e91f7a95c12309e22644c5c32bcbbb3a
author Yunqing Wang <yunqingwang@google.com> Fri May 10 18:46:43 2013 -0700
committer Yunqing Wang <yunqingwang@google.com> Mon May 13 12:14:09 2013 -0700
tree 996ae3c2973ee58b61b36d6e86104a20cae181e1
parent 9f5811c2da890c8bd675ed3112692a43633ff003

Do joint motion search iteratively

Allow motion search multiple times iteratively, and break out
the loop if this search couldn't find better motion vectors.
Limit the maximum number of search to 2.

Tests results:
1. stdhd set: 0.311%(overall psnr); 0.346%(ssim).
positive gain on 10 out of 16 clips(best: 2.746% on sunflower;
worst: -0.434% on old_town_cross).
2. derf set: 0.016%(overall psnr); 0.062%(ssim).
positive gain on half of the clips(best: 0.499% on bowing;
worst: -0.387 on city).

Change-Id: Ibf0a51776d4caf7707be0586346db08128117559