Patent ID: 7623574

Claim:
A computer-implemented method for transforming video information using a computing device that implements a video encoder, the method comprising: with the computing device that implements the video encoder: determining a dominant polarity for a motion vector predictor; determining how to represent the motion vector predictor based at least in part on the dominant polarity; signaling, in a bitstream, polarity selection information for the motion vector predictor; processing a motion vector based at least in part on the motion vector predictor, wherein the processing includes determining motion vector differential information from the motion vector and the motion vector predictor; and signaling, in the bitstream, the motion vector differential information; wherein the motion vector is for a current block or macroblock of an interlaced forward-predicted field currently being coded, and wherein the dominant polarity is based at least in part on reference field polarity of each of plural previous motion vectors for neighboring blocks or macroblocks in the interlaced forward-predicted field.