JP2797942B2 - Video server - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moving image server for distributing moving image data in response to a moving image distribution request from a user.

[0002]

2. Description of the Related Art A moving image source for storing moving image data of a movie or the like is integrated in one place, and the requested moving image data is transferred from the moving image source to a CAT upon request from a user.
A moving image server that distributes to a user via a V network or a public communication line is receiving attention. The moving image server is also used as a video library in libraries and museums.
The distribution of a moving image by the moving image server is performed in such a manner that the requested moving image data is distributed when a request is received from a user. It is different from John Broadcasting and CATV programs.

[0003] In principle, in response to a request from a user, a moving image server distributes moving images in a method called on-demand. The on-demand method is a method in which each user occupies one video source and can fast-forward, rewind, stop, etc. at any time, such as a VTR or video disc, and provides the highest quality service for the user. It is a method that can be supplied.

In the case of the on-demand type, since a plurality of users may request distribution of the same type of moving image data, it is necessary to prepare a plurality of moving image sources holding the same type of moving image data. . FIG. 2 shows that the moving image data is 1
It is a block diagram which shows the structure of the on-demand type | movement moving image server of the case of a kind. In the illustrated moving image server 50, since there are three users 51, the same number as the number of users, that is, three identical types in this example, in this example, in case three users make a moving image distribution request at the same time, is prepared. A moving image source 52 must be prepared. In an on-demand video server, each type of video source needs to be prepared by the number of users, and when the number of users is large, the number of video sources to be prepared becomes extremely large. It becomes economically and technically impractical. Furthermore, despite the small probability that all users request distribution of the same type of moving image data, moving image sources for the number of users will be prepared. There is also a problem that it becomes extremely small.

[0005] The above-mentioned drawback of the on-demand type is solved.
Video distribution method called near-on-demand
There is. Near-on-demand image distribution
One type of moving image data is distributed at fixed time intervals,
Are the moving images at the time when the distribution of the moving images starts.
Start watching. Figure 3 shows a near-on-demand video
FIG. 2 is a block diagram illustrating a configuration of a server. In the example of FIG.
There are five users 51, and a moving image source 53
₁~ 53_ThreeIs provided. Video source 53 ₁~ 53_Three
Is the same type of moving image with a broadcast time of 1 hour (= 60 minutes)
Data is stored and transmitted, but they are broadcast
The start time is off by 20 minutes, and each broadcast is once
It is configured to repeat the broadcast after it is over.
Further, the moving image server includes a moving image from the user 51.
Concentrator 54 for receiving a distribution request and received moving image
A distribution request is sent to each video source 53₁~ 53_ThreeDistribute every
A distribution unit 55 is provided. This near on demand
In the type of moving image server, the user 51 sends a moving image distribution request.
When the operation is performed, the user 51₁~ 5
3_ThreeThe time that the user 51 wished to distribute from any of
From the video source whose broadcast start time is closest to
Wait until the time and watch the video from that video source
Will do. The user 51 is required to start watching
Therefore, it is determined from which video source the video is viewed.
You.

Although the number of users is five in the example shown in FIG. 3, in the case of a near-on-demand type moving image server, the number of moving image sources that must be prepared is broadcast regardless of the number of users. This is a fixed number determined by the interval and the broadcast time.
Therefore, near-on-demand video server
Unlike the on-demand type video source, there is an advantage that even if the number of users is large, it is sufficient to prepare as many video sources as are economically or technically allowable. However, while an on-demand video server can provide the highest quality services to users, a near-on-demand video server can be used immediately The quality of service is considerably poor, such as not being able to see moving images, fast-forwarding, and rewinding.

[0007]

As described above, the on-demand type moving image server has a problem that it is difficult to realize when the number of users is large, while the near-on-demand type moving image server is difficult. In the case of (1), there is a problem that the quality of service for the user is considerably inferior to that of the on-demand type moving image server.

[0008] An object of the present invention is to provide a moving picture server which is excellent in economy while maintaining the quality of service for users as much as possible.

[0009]

A moving image server according to the present invention monitors a plurality of moving image sources holding moving image data and the number of moving image distribution requests from a user. If the number exceeds a predetermined reference value, a video distribution method instruction is issued that instructs near-on-demand video distribution, otherwise, an on-demand video distribution is instructed. Frequency monitoring means, and switching readout means for reading out moving image data from each of the moving image sources and distributing to the user by using either an on-demand type or near-on-demand method according to the moving image distribution method instruction And

[0010]

A frequency monitoring means for monitoring the number of moving image distribution requests to moving image data and instructing near-on-demand moving image distribution when the moving image distribution request exceeds a predetermined reference value; Switching readout means for distributing moving image data according to an on-demand type or near-on-demand method in response to an instruction from the frequency monitoring means. When the number of moving image distribution requests increases, near-on-demand moving image distribution is performed.

In the present invention, it is preferable that a plurality of moving image sources are provided. Further, the moving image distribution
A plurality of types of moving image data can be prepared by using the program to be requested as a type, and a switching readout unit and a plurality of moving image sources can be provided for each type of moving image data. In this case, a reference value is set for each type of moving image, and the number of moving image distribution requests is compared with the reference value for each type to output a moving image distribution method instruction.

[0012]

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a moving image server according to one embodiment of the present invention.

The moving picture server shown in FIG. 1 can distribute two kinds of moving picture data to users, and two moving picture sources are prepared for each kind of moving picture data. ing. The first type of moving image data is stored in moving image sources 13 ₁ and 13 ₂ , and the second type of moving image data is stored in moving image sources 14 ₁ and 14 ₂ .
In addition, a concentrator 21 that receives moving image distribution requests from many users 20, a distributor 22 that distributes the received moving image distribution requests for each type of moving image data, and a frequency of the received moving image distribution request. A frequency monitoring unit 10 for monitoring and outputting a moving image distribution method instruction is provided. further,
First and second switching units 11 and 12 and first and second reading units 15 and 16 are provided corresponding to the first and second types of moving image data, respectively.

The first readout unit 15 accesses the moving image sources 13 ₁ and 13 ₂ storing the first type of moving image data in response to the input moving image distribution request, and receives a moving image from the accessed moving image server. The user 20 reads out the image data and
A processing unit for performing on-demand type moving image distribution and a processing unit for performing near-on-demand type moving image distribution are provided therein. When a moving image distribution request is input to the on-demand type processing unit, the first readout unit 15 responds to the moving image distribution request in response to the moving image data from the moving image sources 13 ₁ and 13 _2. When a moving image distribution request is input to the near-on-demand type processing unit, the moving image sources 13 ₁ and 13 ₂ have a predetermined time lag between each other, that is, the moving image The transmission of data is repeated, and the video is distributed on a near-on-demand type in accordance with the input video distribution request and the scheduling of the video sources 13 ₁ and 13 ₂ . The second reading unit 16 is also moving image source 14 ₁ storing the second type of video data, 14 ₂ as the target, and is configured to perform the same operation as the first reading unit 15.

A moving image distribution request relating to the first type of moving image data is input from the distribution unit 22 to the first switching unit 11, and the first switching unit 11 receives the moving image from the frequency monitoring unit 10. In response to the image distribution method instruction, the input moving image distribution request is output to either the on-demand type processing unit or the near-on-demand type processing unit of the first reading unit 15. ing. Similarly, the second switching unit 12 sends the moving image distribution request for the second type of moving image data to the on-demand type processing unit or the near-on-demand type processing unit of the second reading unit 16. For outputting to one of the units in response to a moving image distribution method instruction.

The frequency monitoring unit 10 monitors the number of moving image distribution requests from the user 20 for each type of moving image data, and outputs a reference value determined for each moving image data and a corresponding moving image data. The number of moving image distribution requests is compared with each other, and a moving image distribution method instruction is transmitted to the switching unit corresponding to the corresponding moving image data. In this case, when the number of requested moving image distributions is smaller than a preset reference value, the moving image data is distributed on demand, and the requested number of moving image distributions is smaller than the reference value. Is larger, a moving image distribution method instruction is output so as to distribute moving image data in a near-on-demand manner.

Next, the operation of this embodiment will be described.
Here, as an initial state, it is assumed that each of the switching units 11 and 12 is switched to the on-demand type.

When the user 20 makes a moving image distribution request to the moving image server of the present embodiment, the moving image distribution request is accepted by the concentrator 21 and the moving image data of the type specified by the distributor 22. Is sent to the switching unit corresponding to. On the other hand, the frequency monitoring unit 10 constantly monitors the number of moving image distribution requests for each type of moving image data. For example, if the number of moving image distribution requests from the user 20 for the first type of moving image data is If it is determined that the reference value is smaller than the reference value set for one type of moving image data, it means that on-demand type moving image distribution is possible as usual, A moving image distribution method instruction for instructing on-demand moving image distribution is sent to the moving image data switching unit 11. As a result, the first switching unit 11 remains set to the on-demand type and does not change, and the moving image distribution request from the user 20 is input to the on-demand type processing unit of the first reading unit 15. The moving image data is distributed on demand from the moving image sources 13 ₁ and 13 ₂ to the user 20 who has issued the moving image distribution request.

On the other hand, as a result of monitoring by the frequency monitoring unit 10, the number of distribution requests from the user 20 for the second type of moving image data is determined by a reference value preset for the moving image data. Suppose that it was judged that it exceeded. In this case, the number of moving image distribution requests is larger than the number of moving image sources, and it is impossible to distribute moving images on demand. The frequency monitoring unit 10 sends a moving image distribution method instruction for instructing a near-on-demand type moving image distribution to the second type moving image data switching unit 12. In response to this instruction, the second switching unit 12 transmits a moving image distribution request from the user 20 to the near-on-demand type processing unit of the second reading unit 16, and the second reading unit 16 Video source 14 ₁ , 1 by on-demand video distribution
4 ₂ of the moving image data distributed to the user 20. The frequency monitoring unit 10 constantly monitors the number of moving image distribution requests,
Here, when the number of moving image distribution requests for the second type of moving image data becomes smaller than the reference value, the frequency monitoring unit 10 performs the second moving image distribution so as to perform the on-demand type moving image distribution. The second switching unit 12 transmits a moving image distribution request to the on-demand type processing unit of the second reading unit 16 by sending a moving image distribution method instruction to the switching unit 12 of The read-out unit 16 of the second unit is a video source 14 ₁ , 1 by on-demand type video distribution.
The moving image data 4 in ₂ distributes to the user 20.

As described above, in this embodiment, when the distribution request for a certain type of moving image data is small, on-demand type moving image distribution is performed on the moving image data, and the distribution request increases. Only when is a near-on-demand type moving image distribution performed.

[0021]

As described above, the present invention monitors the number of moving image distribution requests for moving image data, and if the moving image distribution request exceeds a predetermined reference value, it is a near-on-demand type. Frequency monitoring means for instructing the distribution of moving image data, and switching readout means for distributing moving image data by an on-demand type or near-on-demand type method in accordance with an instruction from the frequency monitoring means. Normally, on-demand video distribution is performed, and when the number of video distribution requests increases, near-on-demand video distribution is performed. . First, there is no need to prepare moving image sources for the number of users for each type of moving image data, and it is sufficient to prepare a fixed number of moving image sources smaller than the number of users. Become. Normally, on-demand video distribution is performed, and near-on-demand video distribution is performed only when there is a large number of video distribution requests. The quality of service is improved. When the number of users is large, it is generally considered that the probability that the moving image distribution requests from a large number of users are concentrated on a specific type of moving image data is extremely small, so that the number of users is considerably smaller than the number of users. Even if only a moving image source is prepared, the moving image server of the present invention operates as an on-demand moving image server most of the time.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a moving image server according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of an on-demand video server.

FIG. 3 is a block diagram illustrating a configuration of a near-on-demand type moving image server.

[Explanation of symbols]

10 frequency monitor 11, 12 switching unit 13 _1, 13 _2, 14 _1, 14 _2, 52, 53 ₁ to 53 ₃ moving image source 15 reading unit 20,51 the user 21, 54 concentrator unit 22,55 distribution Part 50 Video server

Claims (3)

(57) [Claims] 1. A moving image server for distributing moving image data in response to a moving image distribution request from a user, wherein a moving image source holding moving image data and the number of the moving image distribution requests are monitored. If the number of the moving image distribution requests exceeds a predetermined reference value, a moving image instructing near-on-demand moving image distribution; otherwise, a moving image instructing on-demand moving image distribution Frequency monitoring means for outputting an image distribution method instruction; and reading the moving image data from the moving image source by one of an on-demand type and a near-on-demand type in response to the moving image distribution method instruction to the user. A moving image server comprising: switching readout means for distributing. 2. The moving image server according to claim 1, wherein a plurality of moving image sources are provided. 3. A program which is a target of the moving image distribution request.
A plurality of types of moving image data is held as the type that,
The switching readout unit and a plurality of moving image sources are provided for each type, the reference value is set for each type, and the frequency monitoring unit issues a moving image distribution request for the type of moving image data for each type. 3. The moving image server according to claim 2, wherein the moving image server outputs the moving image distribution method instruction by comparing the moving image distribution method instruction with the reference value regarding the type.