7 069 332

7,069,332 Title:

Video server for video distribution system

Abstract:

A video server for distributing a digitized video content includes a unit for determining whether or not a video content requested from a terminal is stored in the video server, a unit for issuing a transmission request to another server for transmitting the video thereto in accordance with the HTTP protocol when the video content requested from the terminal is not stored in the video server, and a unit for receiving the video content transmitted from the other video server in accordance with the HTTP protocol, and transmitting the video content to the terminal in accordance with IP multicast or HTTP protocol.

Claims:

What is claimed is:

1. A video server for distributing a digitized video content, comprising: means for determining whether or not a video content requested from a terminal is stored in saidvideo server; means for transmitting a transmission request to another video server for transmitting said video content from said another video server when the video content requested by the terminal is not stored in said video server, said transmissionrequest being formatted according to the Hyper Text Transfer Protocol (HTTP); and means for receiving the video content transmitted from the other video server, the video content transmitted from the other video server in response to the request beingformatted in accordance with the HTTP, and transmitting the video content received from the other video server or as stored in said video server to said terminal, the video content transmitted to said terminal being formatted in accordance with multicastInternet Protocol (IP).

2. A video server according to claim 1, wherein said transmitting means further includes means for transmitting the video content received from the other video server to said terminal in accordance with the HTTP.

3. A video server according to claim 1, further comprising: means for storing and managing the video content received from the other video server.

4. A video server according to claim 2, wherein said means for transmitting a video content to the terminal in accordance with the HTTP establishes a plurality of logical transmission paths between said terminal and said video server, andutilizes said plurality of logical transmission paths for transmitting image information.

5. A video server for distributing a digitized video content, comprising: means for determining whether or not a video content requested from a terminal is stored in said video server; means for transmitting a transmission request to anothervideo server for transmitting said video content in accordance with Hyper Text Transfer Protocol (HTTP) when the video content requested by the terminal is not stored in said video server; and means for receiving the video content transmitted from theother video server in accordance with the HTTP, and transmitting the video content to said terminal in accordance with Internet Protocol (IP) multicast, wherein said transmitting means includes a plurality of buffers, buffer selecting means, and areference time generator; said transmitting means detects a random access point in image information, and stores the image information up to the next random access point in one of said plurality of buffers; and said buffer selecting means selects, fromamong said plurality of buffers, image information which as not been transmitted and has a time stamp equal to or smaller than a reference time generated by said reference time generator, and indicates the selected image information to said transmittingmeans.

6. A method of distributing a video content in a video server, comprising the steps of: receiving an audience request from a terminal; determining whether or not a requested video program is stored in said video server; transmitting saidvideo program to the terminal when the requested video program is stored in said video server, the video program transmitted to the terminal being formatted according to the multicast Internet Protocol (IP); accessing by sending a request formattedaccording to the Hyper Text Transfer Protocol (HTTP) to another video server when the requested video program is not stored in said video server to request said other video server to transmit the video program; and upon receiving the video program fromsaid other video server, transmitting the received video program to the terminal, the received video program being transmitted to the terminal being formatted according to the multicast IP.

7. A video distribution method according to claim 6, wherein the video program from the other video server is received in accordance with Hyper Text Transfer Protocol (HTTP).

8. A computer program, on a storage medium, for distributing a video from a video server, said computer program when executed causes said video server to perform the steps of: receiving an audience request from a terminal; determining whetheror not a requested video program is stored in said video server; transmitting said video program to the terminal when the requested video program is stored in said video server, the video program transmitted to the terminal being formatted according tothe multicast Internet Protocol (IP); accessing by sending a request formatted according to the Hyper Text Transfer Protocol (HTTP) to another video server when the requested video program is not stored in said video server to request the other videoserver to transmit the video program; and upon receiving the video program from said other video server, transmitting the received video program to the terminal the received video program transmitted to the terminal being formatted according to themulticast IP.