Patent ID: 7844624

Claim:
An information delivery system for delivering media data such as audio and video to a client terminal, comprising: a memory configured to store the media data including a plurality of scenes, each scene having a predetermined total time duration; a meta-information storing unit configured to store first meta-information which includes a start-time and a total-time of a scene; a user database configured to store a user identifier of a user in association with an access privilege of the user, the access privilege indicating whether the scene is allowed for the user to view, and specifying an allowable time range out of the predetermined total time duration of the scene which the user is allowed to retrieve for viewing, wherein the user is prohibited from viewing any portion of the media data that is not included in the allowable time range and the content of the access privilege is not determined by the user; a media control request generator configured to generate a media control request which requests delivery of the media data and to add the user identifier to the generated media control request; an authenticator configured to convert the first meta-information to a second meta-information which includes the allowable time range included in the access privilege according to the access privilege corresponding to the user identifier added to the media control request, and to set duration of the one scene as the allowable time range for the user to view; a presentation description data generator configured to generate a presentation description data by using the second meta-information, the presentation description data indicating the allowable time range specified by the access privilege and being used by a client terminal to request a delivery of media data, a retriever configured to retrieve the media data based on receiving the presentation description data from the client terminal; and a deliverer configured to deliver a retrieved media data to the client terminal.