Joint motion vector encoding scheme with a pooled macroblock type

Motion vectors correlate very well with other neighboring motion vectors. Thus, many macroblocks have zero residual motion vectors within their blocks after differential pulse coded modulation using their individually predicted motion vectors. Motivated by this observation, we develop a new joint encoding scheme of motion vectors by defining a new macroblock coding mode called pooled zero motion vector difference coding to jointly code such cases more efficiently. Experimental results with several well-known video test sequences verify that the proposed method improves the coding efficiency up to 6.2% compared to the H.264advanced video coding (AVC).