1. An information product, comprising: a computer readable medium; information stored on the computer readable medium that is indicative of an index for an interleaved data stream in which elements including samples of at least one data type have an order in the interleaved data stream different from an order in which the samples are presented, and wherein elements including samples of data of each type in a time based segment are combined into groupings, the index comprising: for each grouping, an entry comprising: a temporal offset to another grouping, wherein the temporal offset of a first grouping indicates an offset in the interleaved data stream between the first grouping and a second grouping containing data for a presentation time corresponding to the position of the first grouping in the interleaved data stream; at least one offset in the interleaved data stream of the grouping; and other information enabling access to data of a sample of each data type in the elements of the grouping.