• Yunqing Wang's avatar
    Reuse neighbor's warped motion parameters · 876a8b0b
    Yunqing Wang authored
    If a block's motion_mode is WARPED_CAUSAL and its mode is NEARESTMV, search
    its immediate above and left neighbors to get the set of neighbor blocks
    using WARPED_CAUSAL motion mode, pick the one with largest block size, and
    use that neighbor's warped motion parameters directly for the current block.
    If none of the neighbors uses WARPED_CAUSAL motion mode, we estimate the
    current block's warped motion parameters.
    Before this patch, for every block, we estimate its warped motion parameters.
    With this patch, we reduce the number of blocks doing parameter estimation.
    Here are results by testing on clips with camera motions.
                        WARPED_CAUSAL blocks   blocks reusing parameters
    station2_240p(30f):     3857                    1678
    netflix_arieal(30f):     692                     223
    No noticable changes in coding gain. Borg test result showed a PSNR
    change of +0.006% on cam_lowres set, and -0.014% on lowres set.
    Change-Id: If12387ad0ca8a1996ea4c3f1bedcb269ebf78c6c