Patent ID: 8457473

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 by playlist information, the playlist information including synchronous information and end point information, the synchronous information including timing information that indicates, on a timeline of the primary playback section, a synchronization point for synchronizing the secondary playback section with the primary playback section, when set to an undefined value, the timing information indicating that the synchronization point that is dynamically set to a time at which a predetermined user operation is received during playback of the primary playback section, and the substream being associated with an entry map, the playback device comprising: a first conversion unit operable to convert a playback point on the timeline of the primary playback section into a corresponding address on the main stream; a second conversion unit operable to (i) covert a playback point on the timeline of the primary playback section into a corresponding playback point on the timeline of the secondary playback section, by using the synchronous information included in the playlist information, and (ii) convert the playback point obtained by the conversion by the second conversion unit into a corresponding address on the substream, by using the entry map associated with the substream; 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 substream read by the reading unit, wherein the main stream is a digital stream carrying primary video, the substream is a digital stream carrying secondary video, the playback unit includes: a first decoder operable to decode the main stream to obtain the primary video; and a second decoder operable to decode the substream to obtain the secondary video, the playback device further comprises a composite unit operable to present, on a same screen, playback of the primary video obtained by the first decoder and the secondary video obtained by the second decoder, by overlaying the secondary video on the primary video, and the playback unit ends the playback of presenting the primary video and the secondary video on the same screen, when a current playback point on the primary playback section reaches an end point that is on the secondary playback section and indicated by the end point information.