This has been found to be better than the original version in both ways:
(1) Better compression: lowres -0.229, midres -0.147
(2) Faster too in my quick test over 5 different clips with 30
frames: 2.7% to 10.5% faster.

Change-Id: I4d46e0915d6e4b8e7bfc03d0c8b88cbe3351ca20