ILVUmv. . . where i is a sequential value indicative of a video object (VOB) and ranges from 1 to m, and j is a sequential value indicative of an interleave unit (ILVU) and ranges from 1 to v, obtaining a data quantity d1 stored to the track buffer at a differential rate Vr???Vo during a time t1, said time t1 being a period during which a bit stream constituting said interleave unit (ILVUij) is re