INFORMATION RECORDING MEDIUM, DATA SORTING DEVICE, AND DATA REPRODUCING DEVICE

摘要

An information recording medium on which an access unit containing basic data and extension data is so recorded that a decoder for decoding only the basic data can process the access unit containing the basic data and the extension data compatible with the next generation. On the information recording medium, a stream composed of a plurality of access units and containing at least either an image or sound is recorded. One access unit has basic data and extension data related to the basic data. The basic data can be decoded into a complete state without necessity of the extension data. The extension data is for improving the quality of data created from the basic data. Information representing that the extension data is contained in the access unit is stored in an area not identified by the decoder decoding only the basic data.