Video proxy server

• US 20020188692A1
• Filed: 05/09/2002
• Published: 12/12/2002
• Est. Priority Date: 05/10/2001
• Status: Active Grant

• Current Assignee: Sun Patent Trust
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Horiuchi, Masaki, Harumoto, Hideaki
• Granted Patent: US 7,099,953 B2
• Time in Patent Office: Days
• US Class Current: 709/213
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04L 65/1104 Session initiation protocol [SIP]
• CPC Class Codes: H04L 65/612 for unicast
• CPC Class Codes: H04L 67/2871 Implementation details of single intermediate entities
• CPC Class Codes: H04L 9/40 Network security protocols
• CPC Class Codes: H04N 21/23106 involving caching operations prefetching while addressing of a memory level in which the access to the desired data or data block requires associative addressing means within memory systems or architectures G06F12/0862; caching at an intermediate stage in a data network H04L67/568

Abstract

Provided is a video proxy server capable of streaming video data after a seek position in quick response to a request from a terminal while caching it without any loss. When the video proxy server receives a seek playback request while executing a video caching operation of receiving video data from a content server 20, caching it, and streaming it to a terminal 21, the video proxy server starts receiving video data after the seek position from the content server 20, caching it, and streaming it to the terminal 21 while continuing the above video caching operation.

Claims

1. A video proxy server, provided between a content server storing video data and a terminal capable of video playback, for receiving the video data from the content server, caching the video data, and streaming the video data to the terminal for playback, the video proxy server comprising:

a request receiving section for receiving a request from the terminal;

a video receiving section for receiving the video data from the content server based on the request from the terminal;

a video cache section for caching the video data received by the video receiving section; and

a video streaming section for streaming the video data cached by the video cache section to the terminal, wherein

when the request receiving section receives a playback request, the video receiving section starts a video receiving operation of receiving the video data from the content server,

when the request receiving section receives a seek playback request while the video receiving section is executing the video receiving operation, the video receiving section starts receiving video data after a seek position from the content server while continuing the video receiving operation, and

the video cache section includes

a cache area for caching the video data received by the video receiving section from the content server, and

a temporary cache area for temporarily caching the video data after the seek position received by the video receiving section from the content server.

2. The video proxy server according to claim 1, wherein

when the request receiving section receives the playback request, the video streaming section starts reading the video data from the cache area and streaming the video data to the terminal,

when the request receiving section receives the seek playback request while the video receiving section is receiving the video data from the content server, the video streaming section stops reading the video data from the cache area and streaming the read video data to the terminal, and starts reading the video data cached in the temporary cache area and streaming the read video data to the terminal.

3. The video proxy server according to claim 1, wherein

when the request receiving section receives a stop request while the video receiving section is receiving the video data after the seek position from the content server in response to the seek playback request, the video cache section clears the temporary cache area.

4. The video proxy server according to claim 1, wherein

when the request receiving section receives a next seek playback request while the video receiving section is receiving the video data after the seek position from the content server in response to the seek playback request, the video cache section clears the temporary cache area, and then starts caching the video data after a next seek position in the temporary cache area.

5. The video proxy server according to claim 1, wherein

the video receiving section receives the video data or the video data after the seek position based on the request from the terminal only when the requested video data or the requested video data after the seek position has not been cached by the video cache section.

6. A video proxy server, provided between a content server storing video data and a plurality of terminals capable of video playback at playback speeds differed from each other, for receiving the video data from the content server, caching the video data, and streaming the video data to the terminals for playback, the video proxy server comprising:

a speed managing section for managing the playback speeds of the terminals;

a video receiving section for receiving the video data from the content server;

a video cache section for caching the video data received by the video receiving section; and

a video streaming section for streaming the video data cached by the video cache section to the terminals at speeds corresponding to the respective playback speeds of the terminals, wherein

the video receiving section receives the video data from the content server at a speed Vmax corresponding to a speed that is the highest of the playback speeds of the terminals managed by the speed managing section.

7. The video proxy server according to claim 6, further comprising a request receiving section for receiving a request from each of the terminals, wherein

when the request receiving section receives a speed-change request for changing the speed Vmax at which the video data is being received from the content server to a speed V, the video receiving section compares the speed V with the speed Vmax and, when the speed V>

the speed Vmax, moves to an operation of receiving the video data from the content server at the speed V.

8. The video proxy server according to claim 7, wherein

when the speed V<

the speed Vmax, the video receiving sect ion continues receiving the video data from the content server at the speed Vmax.

9. The video proxy server according to claim 6, further comprising a request receiving section for receiving a request from each of the terminals, wherein

when the request receiving section receives a stop request while the video receiving section is receiving the video data from the content server at the speed Vmax, the video receiving section moves to an operation of receiving the video data from the content server at a speed V'"'"'max corresponding to a speed that is the highest of the playback speeds, managed by the speed managing section, of the terminals except the terminal that made the stop request.

10. The video proxy server according to claim 6, further comprising a request receiving section for receiving a request from each of the terminals, wherein

when the request receiving section receives a stop request while the video receiving section is receiving the video data from the content server at the speed Vmax, the video receiving section compares a speed V'"'"'max corresponding to a speed that is the highest of the playback speeds, managed by the speed managing section, of the terminals except the terminal that made the stop request with a predetermined speed Vdef, and when the speed V'"'"'max>

the speed Vdef, the video receiving section moves to an operation of receiving the video data from the content server at the speed V'"'"'max.

11. The video proxy server according to claim 10, wherein

when the speed V'"'"'max<

the speed Vdef, the video receiving section moves to an operation of receiving the video data from the content server at the speed Vdef.

12. A video streaming method carried out between a content server storing video data and a terminal capable of video playback, for receiving the video data from the content server, caching the video data, and streaming the video data to the terminal for playback, the method comprising the steps of:

receiving a request from the terminal;

receiving the video data from the content server based on the request from the terminal;

caching the video data received in the video receiving step; and

streaming the video data cached in the video caching step to the terminal, wherein

in the video receiving step,

when a playback request is received in the request receiving step, a video receiving operation of receiving the video data from the content server is started and, when a seek playback request is received in the request receiving step while the video receiving operation is being executed, an operation of receiving video data after a seek position from the content server is started while the video receiving operation is being continued, and

in the video caching step,

when the playback request is received in the request receiving step, a video caching operation of caching the video data received in video receiving step from the content server is started, and

when the playback request is received in the request receiving step while the operation of receiving the video data from the content server is being executed, an operation of temporarily caching the video data after the seek position received in video receiving step from the content server while the video caching operation is being executed is continued.

13. A program that describes a video streaming method carried out between a content server storing video data and a terminal capable of video playback, for receiving the video data from the content server, caching the video data, and streaming the video data to the terminal for playback, the method comprising the steps of:

receiving a request from the terminal;

receiving the video data from the content server based on the request from the terminal;

caching the video data received in the video receiving step; and

streaming the video data cached in the video caching step to the terminal, wherein

in the video receiving step,

when a playback request is received in the request receiving step, a video receiving operation of receiving the video data from the content server is started and,

when a seek playback request is received in the request receiving step while the video receiving operation is being executed, an operation of receiving video data after a seek position from the content server is started while the video receiving operation is being continued, and

in the video caching step,

when the playback request is received in the request receiving step, a video caching operation of caching the video data received in video receiving step from the content server is started, and

when the playback request is received in the request receiving step while the operation of receiving the video data from the content server is being executed, an operation of temporarily caching the video data after the seek position received in video receiving step from the content server while the video caching operation is being executed is continued.

14. A video streaming method carried out between a content server storing video data and a plurality terminals capable of video playback at playback speeds differed from each other, for receiving the video data from the content server, caching the video data, and streaming the video data to the terminals for playback, the method comprising the steps of:

managing the playback speeds of the terminals;

receiving the video data from the content server;

caching the video data received in the video receiving step; and

streaming the video data cached by the video caching step to the terminal at speeds corresponding to the respective playback speeds of the terminals, wherein

in the video receiving step, the video data is received from the content server at a speed Vmax corresponding to a speed that is the highest of the playback speeds of the terminals managed in the speed managing step.

15. A program that describes a video streaming method carried out between a content server storing video data and a plurality terminals capable of video playback at playback speeds differed from each other, for receiving the video data stored in the content server, caching the video data, and streaming the video data to the terminals for playback, the method comprising the steps of:

managing the playback speeds of the terminals;

receiving the video data from the content server;

caching the video data received in the video receiving step; and

streaming the video data cached by the video caching step to the terminals at speeds corresponding to the respective playback speeds of the terminals, wherein

in the video receiving step, the video data is received from the content server at a speed Vmax corresponding to a speed that is the highest of the playback speeds of the terminals managed in the speed managing step.