Multimedia-data transmission system, apparatus and method

• US 20020040478A1
• Filed: 09/26/2001
• Published: 04/04/2002
• Est. Priority Date: 10/03/2000
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Ando, Tsutomu
• Granted Patent: US 7,587,735 B2
• Time in Patent Office: Days
• US Class Current: 725/90
• CPC Class Codes: H04N 21/2181 comprising remotely distributed storage units, e.g. when movies are replicated over a plurality of video servers distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS], H04L67/1097
• CPC Class Codes: H04N 21/23103 using load balancing strategies, e.g. by placing or distributing content on different disks, different memories or different servers storage management G06F3/0604; allocation of resources considering the load in multiprogramming arrangements G06F9/505; techniques for rebalancing the load in a distributed system G06F9/5083; access to distributed or replicated servers, e.g. load balancing, in data networks H04L67/1001
• CPC Class Codes: H04N 21/242 Synchronization processes, e.g. processing of PCR [Program Clock References] arrangements for synchronising broadcast or distribution via plural systems in broadcast distribution systems H04H20/18
• CPC Class Codes: H04N 21/43072 of multiple content streams on the same device
• CPC Class Codes: H04N 21/6125 involving transmission via Internet transmission by internet of broadcast information H04H60/82
• CPC Class Codes: H04N 21/8547 involving timestamps for synchronizing content
• CPC Class Codes: H04N 7/17336 Handling of requests in head-ends

Abstract

In a system for transmitting multimedia data including video data, audio data, graphic data, text data and the like via a network, sets of media data are stored in a plurality of servers in a distributed state. When requested multimedia data is assigned from a transmitter, necessary sets of data from among media data stored in the servers in a distributed state are acquired by corresponding receivers in accordance with the assignment. A synchronization control unit and a multiplexer multiplex the acquired media data based on time stamps of the data, and transmit multimedia data after the multiplexing to a client which has assigned the multimedia data. According to such a configuration, distributed multimedia servers can be constructed without taking into consideration of influence by the effective rates of transmission channels from the respective servers.

Claims

1. A multimedia-data transmission system for transmitting multimedia data via a network, said system comprising:

client for assigning multimedia data to be transmitted;

at least one server for storing multimedia data in a distributed state;

at least one receiver corresponding to said at least one server, each for acquiring multimedia data stored in corresponding ones of said at least one server in accordance with the assignment;

multiplexer for multiplexing the acquired multimedia data based on time-management information added to the media data; and

transmission means for transmitting the multiplexed multimedia data obtained as a result of the multiplexing to said client, serving as a source of the assignment.

2. A system according to claim 1, wherein the multimedia data includes at least one of video data, audio data, graphic data and text data.

3. A system according to claim 1 or 2, wherein when a number of said receiver is at least two, each of said at least one receiver further comprises memory for temporarily storing the acquired data, in order to absorb a difference between speeds of transmission of multimedia data with respect to said receiver.

4. A system according to claim 1, further comprising parser for analyzing a multimedia description language describing a mutual relationship among a plurality of multimedia data, transmitted from said client, and time-information memory for storing time-management information for multimedia data output from said parser, wherein said multiplexer multiplexes the acquired media data based on time-management information added to the multimedia data and the time-management information stored in said time-information storage memory.

5. A transmission method for acquiring multimedia data from at least one server storing multimedia data in a distributed state, and for transmitting multimedia data to client, via a network, said method comprising:

an acquisition step of acquiring the multimedia data from the at least one server in accordance with assignment of multimedia data from the client;

a multiplexing step of obtaining multiplexed multimedia data by multiplexing the acquired multimedia data based on time management information added to the acquired multimedia data; and

a transmission step of transmitting the multiplexed multimedia data obtained as a result of the multiplexing to the client, serving as a source of the assignment.

6. A method according to claim 5, wherein the multimedia data includes at least one of video data, audio data, graphic data and text data.

7. A method according to claim 5, further comprising storing step for temporarily storing the acquired data to memory, and wherein in said acquisition step, a difference between speeds of transmission of multimedia data from the at least one server is absorbed utilizing the storage means.

8. A method according to claim 5, further comprising a parser step of analyzing a multimedia description language describing a mutual relationship among a plurality of multimedia data, transmitted from the client, and a time-information storage step of storing time-management information for multimedia data output in said parser step, wherein in said multiplexing step, the acquired multimedia data is multiplexed based on time-management information added to the multimedia data and the time-management information stored in said time-information storage step.

9. A control program for realizing transmission control for acquiring multimedia data from at least one server storing media data in a distributed state, and for transmitting multimedia data to client, via a network by a computer, said control program comprising:

code for acquiring the multimedia data from the at least one server in accordance with assignment of multimedia data from the client means;

code for multiplexing to obtain multimedia data by multiplexing the acquired multimedia data based on time-management information added to the acquired multimedia data; and

code for transmitting the multiplexed multimedia data obtained as a result of the multiplexing to the client, serving as a source of the assignment.

10. A transmission apparatus for acquiring multimedia data from at least one server storing media data in a distributed state, and for transmitting multimedia data to client, via a network, said apparatus comprising:

acquisition means for acquiring the multimedia data from said at least one server in accordance with assignment of multimedia data from said client;

multiplexer means for obtaining multimedia data by multiplexing the acquired multimedia data based on time-management information added to the acquired multimedia data; and

transmission means for transmitting the multiplexed multimedia data obtained as a result of the multiplexing to said client, serving as a source of the assignment.