Patent ID: 7587735
Filing Date: 2009-09-08
Classification: H04N

Abstract:
1. A multimedia-data transmission system for transmitting multimedia data via a network, said system comprising: a plurality of clients, each of which assign via the network multimedia data to be transmitted; a first multimedia data storage server which stores a first type of multimedia data to be reproduced in synchronization with a corresponding second type of multimedia data and transmits via the network the stored first type of multimedia data to a proxy server upon receiving a request for the multimedia data from the proxy server; a second multimedia data storage server which stores the second type of multimedia data, corresponding to the first type of multimedia data, to be reproduced in synchronization with the corresponding first type of multimedia data and transmits via the network the stored second type of multimedia data to the proxy server upon receiving a request for the multimedia data from the proxy server; and a proxy server that receives the first type of multimedia data to be reproduced in synchronization transmitted from the first multimedia data storage server, receives the corresponding second type of multimedia data to be reproduced in synchronization transmitted from the second multimedia data storage server, multiplexes the received first type of multimedia data and the corresponding second type of multimedia data, and transmits the multiplexed multimedia data to at least one of the clients which assign the multimedia data to be transmitted, wherein the proxy server comprises: a first receiver that receives from one of the plurality of clients an assignment of multimedia data to be transmitted to the client; a determiner for determining, based on multimedia data assigned by the one of the plurality of clients, the first multimedia data storage server storing the first type of multimedia data and the second multimedia data storage server storing the second type of multimedia data; a requester for requesting that the first multimedia data storage server provide the first type of multimedia data to be reproduced in synchronization and for requesting that the second multimedia data storage server provide the corresponding second type of multimedia data to be reproduced in synchronization, based on the determination by the determiner; a second receiver for receiving via the network the first type of multimedia data to be reproduced in synchronization transmitted from the first multimedia data storage server and for receiving via the network the corresponding second type of multimedia data to be reproduced in synchronization transmitted from the second multimedia data storage server in accordance with the request by the requestor; a parser for analyzing a multimedia description language describing a mutual relationship among the first type of multimedia data and the second type of multimedia data, transmitted from said client; a reproducing-information memory for storing reproducing information for the first type of multimedia data and the second type of multimedia data output from said parser; a multiplexer for multiplexing the received first type of multimedia data and the corresponding second type of multimedia data based on a timestamp added to the received first type of multimedia data and the second type of multimedia data and the reproducing information stored in said reproducing-information memory; and transmission means for transmitting via the network the multiplexed multimedia data obtained as a result of the multiplexing to said one client which assigned the multimedia data to be transmitted.