Digital video image sequences including slices of macroblocks are encoded by adopting a direct prediction mode, motion-compensated on the basis of motion vectors, chosen from between a direct spatial prediction in which the motion vectors of a given macroblock are obtained from the motion vectors of the macroblocks already encoded within one and the same image, and a direct temporal prediction, in which the motion vectors of a given macroblock are obtained from the motion vectors of the macroblocks belonging to a previously encoded image.