ref: 4e66293fcb5b4779490faf8f40300e7e0096640e
parent: 06159fcd18b3438bb703a2baff4019aa6393b267
author: Yunqing Wang <yunqingwang@google.com>
date: Tue Apr 1 13:32:20 EDT 2014
Use source frame difference to make partition decision Calculate the difference variance between last source frame and current source frame. The variance is calculated at 16x16 block level. The variances are compared to several thresholds to decide final partition sizes. An adaptive strategy is implemented to decide using SOURCE_VAR_BASED_PARTITION or FIXED_PARTITION based on motions in the video. The switching test is done once every search_type_check_frequency frames. The selection of source_var_thresh needs to be investigated further later. RTC set Borg test showed 0.424% overall psnr gain, and 0.357% ssim gain. For clips with large enough static area, the encoding speedup is around 2% to 15%. Change-Id: Id7d268f1d8cbca7fb8026aa4a53b3c77459dc156