Patent ID: 7801415

Claim:
A playback device for executing trick play of a main stream and a substream, a portion of the main stream being defined as a primary playback section, and a portion of the substream being defined as a secondary playback section, the primary and secondary playback sections being defined in playlist information, the playlist information including synchronous information, the synchronous information including timing information that indicates a synchronization point on a timeline of the primary playback section, the synchronization point being a point for starting synchronous playback of the primary playback section with the secondary playback section, the substream being associated with an entry map, and a start point of the trick play being defined on the timeline of the primary stream, the playback device comprising: a first conversion unit operable to convert a playback point into a corresponding address on the main stream; a second conversion unit operable to convert the start point into a corresponding point defined on a timeline of the secondary playback section and to further convert the corresponding point into a corresponding address on the sub stream, the conversion into the corresponding point being performed by using the synchronous information included in the playlist information, and the conversion into the corresponding address being performed by using the entry map associated with the sub stream; a reading unit operable to read the main stream and sub stream starting from the respective addresses obtained by the first and second conversion units; and a playback unit operable to play back the main stream and the substream read by the reading unit, wherein the main stream is a digital stream carrying a first video and is recorded on a first recording medium, the substream is a digital stream carrying a second video and is recorded on either the first recording medium or a second recording medium which is different from the first recording medium, the playback unit includes: a first decoder operable to decode the main stream to obtain the first video; and a second decoder operable to decode the substream to obtain the second video; and the playback device further comprises: a composite unit operable to execute Picture in Picture playback by overlaying, on a same screen, playback of the first video obtained by the first decoder with playback of the second video obtained by the second decoder.