Relay apparatus, system and method, and storage medium

• US 7,664,854 B2
• Filed: 03/12/2004
• Issued: 02/16/2010
• Est. Priority Date: 09/30/1997
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Okazaki, Hiroshi, Tanaka, Kenichiro, Fukasawa, Toshihiko
• Primary Examiner(s): Chankong; Dohm
• Assistant Examiner(s): TRUONG, LAN DAI T
• Application Number:
  US10/798,404
• Publication Number:
  US 20040210667A1
• Time in Patent Office: 2,167 Days
• Field of Search: 709/225, 709/203, 709/223, 709/217, 709/277
• US Class Current: 709/225
• CPC Class Codes: H04N 1/00127 Connection or combination of a still picture apparatus with another apparatus, e.g. for storage, processing or transmission of still picture signals or of information associated with a still picture
• CPC Class Codes: H04N 1/00299 with a television transmission apparatus, e.g. a videophone, a teletext system or a digital television system
• CPC Class Codes: H04N 7/152 Multipoint control units therefor

Abstract

A system enables information transmission between a server which serves information by its own communication format and a client which receives service on a general network, with an efficient and simple structure. A conversion server 101 receives a video transmission request message from a client 103 in the HTTP protocol, the conversion server 101 converts the message into a message of a format of a server 102, and transmits the converted message to the server 102. Then, the conversion server 101 returns video data transferred from the server 102 to the client 103 in the HTTP protocol.

Claims

1. A relay apparatus for delivering live video stream data from a server having an image sensing device to clients via a network, comprising:

a connection management device configured to make a connection with the server having the image sensing device via the network in case that the connection has not been established with the server when a request is received from a client, and to get the live video stream data from the server having the image sensing device;

a memory control device configured to store the live video stream data including sequence information based on a time when the live video stream data is acquired by the image sensing device, from the server having the image sensing device, in a buffer memory;

a first determining device configured to determine whether a second request from a second client is received within a predetermined period after a first request from a first client which is receiving the live video stream data has been received;

a second determining device configured to determine whether the buffer memory stores new live video stream data acquired after the live video stream data has been sent to the second client, based on the sequence information in the second request and the sequence information in the buffer memory, in case that the first determining device determines that the second request is not received within the predetermined period after the first request has been received; and

a delivery device configured to deliver to the first and second clients the live video stream data which is received from the server having the image sensing device in accordance with the first request in case that the first determining device determines that the second request is received within the predetermined period after the first request has been received,

to deliver to the second client the new live video stream data stored in the buffer memory and the live video stream data which is received from the server having the image sensing device after receiving the second request in case that the second determining device determines that the new live video stream data acquired after the live video stream data has been sent to the second client is stored in the buffer memory, and

to deliver to the second client the live video stream data which is received from the server having the image sensing device after the second request is received and not to deliver the live video stream data which has been stored in the buffer memory before the second request is received in case that the second determining device determines that the new live video stream data acquired after the live video stream data has been sent to the second client is not stored in the buffer memory,

wherein the connection management device does not make a second connection with the server other than a first connection in case that the first connection has been established with the server when the request is received from the client.

2. The apparatus according to claim 1, wherein a protocol between the relay apparatus and the clients is HTTP.

3. The apparatus according to claim 1, wherein the connection management device converts a first format of the video stream data to a second format for the clients.

4. The apparatus according to claim 1, wherein the predetermined period is a period between the point where the deliver device receives a request from one of the first and second clients and the point where the deliver device receives a next request from the other of the first and second clients.

5. The relaying method to deliver live video stream data from a server having an image sensing device to clients via the network, comprising the steps of:

making a connection between a relay apparatus and the server having the image sensing device via the network in case that the connection has not been established with the server when a request is received from a client,

getting the live video stream data including sequence information based on a time when the live video stream data is acquired by the image sensing device, from the server having the image sensing device and storing the live video stream data in a buffer memory,

first determining whether a second request from a second client is received within a predetermined period after a first request from a first client which is receiving the live video stream data has been received,

second determining whether the buffer memory stores new Live video stream data acquired after the live video stream data has been sent to the second client, based on the sequence information in the second request and the sequence information in the buffer memory, in case that the first determining step determines that the second request is not received within the predetermined period after the first request has been received, and

delivering to the first and the second clients the live video stream data which is received from the server having the image sensing device in accordance with the first request in case that the first determining step determines that the second request is received within the predetermined period after the first request has been received,

delivering to the second client the live video stream data stored in the buffer memory and the live video stream data which is received from the server having the image sensing device after receiving the second request in case that the second determining step determines that the new live video stream data acquired after the live video stream data has been sent to the second client is stored in the buffer memory, and

delivering to the second client the live video stream data which is received from the server having the image sensing device after the second request is received and not to deliver the live video stream data which has been stored in the buffer memory before the second request is received in case that the second determining step determines that the new live video stream data acquired after the live video stream data has been send to the second client is not stored in the buffer memory,

wherein the making step does not make a second connection with the server other than a first connection in case that the first connection has been established with the server when the request is received from the client.

6. The method according to claim 5, wherein a protocol between the relay apparatus and the clients is HTTP.

7. The method according to claim 5, wherein a first format of the video stream data is converted to a second format for the client.

8. The method according to claim 5, wherein the predetermined period is a period between the point where a request from one of the first and second clients is received in the relay apparatus and the point where a next request from the other of the first and second clients is received in the relay apparatus.

9. A storage medium to store computer program to execute a relaying method to deliver live video stream data from a server having an image sensing device to clients via a network, the computer program comprising the codes of:

making a connection between a relay apparatus and the server having the image sensing device via the network in case that the connection has not been established with the server when a request is received from a client,

getting the live video stream data including sequence information based on a time when the live video stream data is acquired by the image sensing device, from the server having the image sensing device and storing the live video stream data in a buffer memory,

first determining whether a second request from a second client is received within a predetermined period after a first request from a first client which is receiving the live video stream data has been received,

second determining whether the buffer memory stores new live video stream data acquired after the live video stream data has been sent to the second client, based on the sequence information in the second request and the sequence information in the buffer memory, in case that the first determining step determines that the second request is not received within the predetermined period after the first request has been received,

delivering to the first and the second clients the live video stream data which is received from the server having the image sensing device in accordance with the first request in case that the first determining step determines that the second request is received within the predetermined period after the first request has been received,

delivering to the second client the live video stream data stored in the buffer memory and the live video stream data which is received from the server having the image sensing device after receiving the second request in case that the second determining step determines that the new live video stream data acquired after the live video stream data has been sent to the second client is stored in the buffer memory, and

delivering to the second client the live video stream data which is received from the server having the image sensing device after the second request is received and not to deliver the live video stream data which has been stored in the buffer memory before the second request is received in case that the second determining step determines that the new live video stream data acquired after the live video stream data has been send to the second client is not stored in the buffer memory, wherein the making step does not make a second connection with the server other than a first connection in case that the first connection has been established with the server when the request is received from the client.

10. The storage medium according to claim 9, wherein a protocol between the relay apparatus and the clients is HTTP.

11. The storage medium according to claim 9, wherein a first format of the video stream data is converted to a second format for the clients.

12. The storage medium according to claim 9, wherein the predetermined period is a period between the point where the deliver device receives a request from one of the first and second clients and the point where the deliver device receives a next request from the other of the first and second clients.