1. A decoding method using a processor, the method comprising: accessing, by the processor, a sequence of predicted and bidirectional predicted frames each comprising pixel values arranged in macroblocks, wherein at least one macroblock within a bidirectional predicted frame is determined using direct mode prediction based on motion vectors from two or more referenceable frames, wherein at least one such motion vector is scaled by a frame scale fraction, and wherein at least two or more of the referenceable frames are in prior display order.