US Patent 11641467 Sub-block based prediction

A method for video processing includes: determining, that the video block is split into a plurality of sub-blocks based on a condition associated with the video block, refining motion information of each sub-block using a motion refinement process, the motion refinement process being a one-step or an iterative multi-step refinement process; and performing a video processing on the video block based on the refined motion information of each sub-block.