Hardware efficient decoder side motion vector refinement

Abstract

Various hardware arrangements for use with a hardware decoder are described to perform motion vector (MV) refinement. A buffer stores pixel values for a first prediction block identified by a first initial MV and pixels defined by a first search area and stores a second prediction block identified by a second initial MV and pixels defined by a second search area. The first and second initial MVs were used for inter prediction of a block of image data. Second hardware components determine, for multiple pixel locations defined by respective offsets, a respective difference value between the blocks shifted by the offsets. A third hardware component determines a minimum of the difference values to identify an offset MV for MV refinement, and a fourth hardware component outputs one or more refined values based on the offset MV to reconstruct a sub-block of the block.