| 摘要 |
<p>There was an issue in conventional technology in that, when a portion of a plurality of contents that should be having the same viewing/listening period is written onto a commutative medium before the viewing/listening period thereof is established, the viewing/listening period of the plurality of contents could not be synchronized. A content receiver (903) is provided with a viewing/listening license invalidation unit (922) for invalidating a viewing/listening license of content the viewing/listening period of which is not established yet, and first control units (907, 910). When a content is to be played, the first control unit establishes a viewing/listening period when the viewing/listening license is valid, and when the viewing/listening license is invalid, the first control unit transmits a viewing/listening license request that includes a request for establishing a viewing/listening period, to a license server (902), and receives an established viewing/listening period from the license server. When content is to be written onto a commutative medium (911) before playing the content, the viewing/listening license thereof is invalidated if the viewing/listening license thereof has been validated, and then, an un-established viewing/listening period is written onto the commutative medium.</p> |
