Patent ID: 7567617

Claim:
In a computing device that implements a video decoder, a method of video decoding comprising: with the computing device that implements the video decoder, computing a motion vector predictor for a motion vector for a portion of an interlaced P-field, wherein the motion vector predictor predicts the motion vector for the portion of the interlaced P-field, and wherein the computing includes selecting between: using, as the motion vector predictor, a same polarity motion vector predictor that references a first reference field of the interlaced P-field, the first reference field having same polarity as the interlaced P-field, or using, as the motion vector predictor, an opposite polarity motion vector predictor that references a second reference field of the interlaced P-field, the second reference field having opposite polarity as the interlaced P-field; with the computing device that implements the video decoder, processing the motion vector based at least in part on the motion vector predictor computed for the motion vector, wherein the processing comprises reconstructing the motion vector from a motion vector differential and the motion vector predictor; and with the computing device that implements the video decoder, decoding the portion of the interlaced P-field using the motion vector.