US Patent 8213509 Video coding on parallel processing systems

A method of estimating motion is disclosed. A first plurality of candidates is identified in a reference frame, wherein the total area occupied by the first plurality of candidates is substantially smaller than that of the reference frame. A first refinement search is then performed based, at least in part, on the first plurality of candidates. One or more best candidates are then identified based, at least in part, on the first refinement search. Finally, motion data is encoded based, at least in part, on the one or more best candidates.