Patent ID: 6909748

Claim:
A method for motion searching each macroblock of a video frame, comprising iteratively decreasing block size until a rate-distortion (RD) has been minimized and selectively reducing the number of block sizes searched, wherein said motion searching each block of said video frame comprises: performing a motion search on said video frame relative to a previous video frame using 16×16, 8×16 and 16×8 block sizes'; calculating a rate-distortion (RD) for each of said 16×16, 8×16 and 16×8 block sizes; if said calculated RD is lowest for said 16×16 block size, motion search is complete, otherwise continue; performing a motion search on said video frame relative to said previous video frame using an 8×8 block size; calculating a RD for said ×8 block size; if said calculated AD for said 8×8 block size is not lower than said calculated RD for said said 16×16, 8×16 and 16×8 block sizes then said motion search is complete, otherwise continue; performing a motion search on said video frame relative to said previous video frame using 4×8 and 8×4 block sizes; calculating a RD for said 4×8 and 8×4 block sizes; if neither of said calculated RDs for said 4×8 and 8×4 block sizes is lower than said calculated RD for said 16×16, 8×16, 16×8 and 8×8 block sizes, then said motion search is complete, otherwise continue; performing a motion search on said video frame relative to said previous video frame using a 4×4 block size; and determining a block size with lowest calculated RD and motion search is complete.