A video encoder includes an entropy encoder that computes a predicted motion vector (PMV) for each of a plurality of macroblocks in a video frame based on motion vectors of multiple other macroblocks. The video encoder also includes a motion estimator that determines a predicted motion vector for a given macroblock by reusing, as the predicted motion vector for the given macroblock, only the PMV computed by the entropy encoder for a macroblock immediately on top of the given macroblock.