1. A method of video processing comprising: determining, for a search block within a first frame, a relative location of a corresponding block in a second frame with respect to the search block based on comparative searching at a predetermined granularity to produce a motion vector for the search block with a first precision; determining correlation values with respect to the search block for the corresponding block and for at least one block defined at a relative location of less than the predetermined granularity with respect to the corresponding block; and determining a refined motion vector for the search block with a second higher precision based on the relative location of the block having a selected correlation value that is selected from among the correlation values with respect to the corresponding block and the at least one block.