US Patent 7885516 Playback apparatus, program, playback method

When playing an AV Clip recorded on a BD-ROM, a judgment is made, for each elementary stream, which of a plurality of predetermined conditions the elementary stream satisfies. The plurality of predetermined conditions include (a) a condition that a playback apparatus has a capability of playing the elementary stream, (b) a language attribute of the elementary stream matches a language setting of the playback apparatus, and (c) a channel attribute of the elementary stream is surround sound and the playback apparatus has a surround output capability. The playback apparatus assigns a priority to each elementary stream based on which conditions the elementary stream satisfies, selects an elementary stream having a highest priority, and plays the selected elementary stream.