JPH09153012A - Multimedia communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a client to access required multimedia data without knowing contents stored in each server at the time when multimedia data is stored in plural server on a network. SOLUTION: Clients 151 to 153 connected to a network 11 access a management system 21 to find addresses of servers 121 , 122 , and 14 and types of multimedia data stored there. When desired data is designated to access the management system 21, multimedia data is transferred from the pertinent server 121 , 122 , or 14 to the client of the request source. Consequently, it is unnecessary for clinents 151 to 153 to preliminarily recognize which of servers 121 , 122 , and 14 the desired multimedia data exists in.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multimedia communication system in which a server on a network stores multimedia data and a client on the network accesses the server.

[0002]

2. Description of the Related Art As described in, for example, Japanese Patent Application Laid-Open Nos. 5-176074 and 4-356844, various kinds of data such as moving images, still images, voices, texts and other data have been developed with the development of computers. A multimedia communication system that handles data related to multimedia (hereinafter simply referred to as multimedia data) is in the spotlight.

FIG. 5 shows a conventional multimedia communication system.
This is an example of the above. In the network 11,
Video server 12 as a server prepared for video₁,
12 _TwoAnd a server prepared for data other than video
All non-video servers 14 and three clients in this example.
15₁, 15_Two, 15_ThreeIs connected. Video
Server 12₁, 12_TwoAnd the non-video server 14 is, for example,
A disk equipped with an external storage device such as an optical disk or magnetic disk.
-It is composed of a personal computer. Cry
Ant also has such personal computers and
Station. Out of this
The non-video server 14 stores still images, audio, and text data.
Or other data (hereinafter referred to as non-moving image data)
Is accumulated. Video data among multimedia data
The data volume of the
It has the characteristic that it has many steps.

Therefore, in the case of non-moving image data, when a transfer request is made from any of the clients 15 ₁ to 15 ₃ (typically referred to as client 15 ₁ below), the non-moving image server 14 receives all the requested requests. Although only a simple operation of transferring non-moving image data is performed, in the case of the moving image servers 12 ₁ and 12 ₂ , it takes a lot of time to send all requested data to the requesting client 15 _1. Will be required. Client 1
_{On the} side of 5 _1, it is necessary to temporarily store the transferred large-capacity moving image data, and the client 15 ₁ itself needs to prepare a storage medium such as a large-capacity memory or hard disk. Therefore, video server 12 for storing video data in a conventional multimedia communication system client 15 _one of the video data is requested from the client 15 ₁ to transfer only the data of the portion to be currently needed in real time I had decided. Due to the above-mentioned circumstances, the moving image servers 12 ₁ and 12 ₂ often adopt a communication method for the purpose of transferring the moving image data required at each time in real time.

On the other hand, non-moving image data composed of still images, voices, text data or other data need not be transmitted in real time. Therefore, these data have been transferred all at once from the non-moving image server 14 due to the efficiency of data communication.

As described above, since the communication methods of moving image data and non-moving image data are completely different from each other, the moving image data is stored in the dedicated moving image servers 12 ₁ and 12 ₂ , and the non-moving image data is stored in the dedicated non-moving image data. Communication is performed by accumulating in the server 14 and considering the characteristics of each data.

When the client 15 ₁ connected to the network 11 desires to access the moving image data, the client 15 ₁ obtains in advance the address information of the moving image server 12 ₁ or 12 ₂ in which the desired moving image data is stored. And
The moving image data is obtained by accessing the moving image server 12 ₁ or 12 ₂ by designating the obtained address and issuing a moving image data transfer request.

On the other hand, the client 15 ₁ is the video server 1
When trying to access one of 2 ₁ and 12 ₂ , there is a case where the upper limit of the number of accesses possessed by this video server 12 ₁ or 12 ₂ is exceeded. In such a case the other multimedia data desired also access the video server 12 ₂ or 12 ₁ as stored in time and the other video server 12 ₂ or access to 12 ₁ is performed.

When the client 15 ₁ desires to access the non-moving image data, necessary information such as the address of the non-moving image server 14 is obtained in advance. Then, by specifying the address, the non-moving image server 14 is accessed to issue a transfer request for the non-moving image data to obtain the necessary non-moving image data.

[0010]

In such a conventional multimedia communication system, firstly, the network 11 is used.
There is a problem that each of the clients 15 ₁ to 15 ₃ connected to the server has to obtain the addresses of the servers 12 ₁ , 12 ₂ and 14 in advance. If the clients 15 ₁ to 15 ₃ do not know these addresses, the servers 12 ₁ and 1 ₁ which store multimedia data
2 ₂ and 14 cannot be accessed.

In addition, conventional multimedia communication such as
In the communication system, secondly, each client 15₁~ 15_Three
Each server 12₁, 12_TwoHow to and 14
Information about whether such multimedia data is stored
There was a problem that it was necessary to obtain it in advance. this
If you do not know such information in advance, even server 1
2 ₁, 12_TwoAnd 14 know each address
No matter where the necessary multimedia data is stored
It is not possible to judge whether or not

A third problem is shown in FIG.
Sea urchin multiple video servers 12₁, 12 _TwoIf exists
What is the behavior each time you access multimedia data
Image server 12₁Or 12_TwoData corresponding to
It was necessary to judge whether or not In Figure 5, the non-video
The number of the server 14 is singular.
There was a problem. In this way, multimedia data of the same type
If there are multiple servers that store data,
Determining whether to gain access is a waste of work. Ma
Individual client 15₁~ 15_ThreeBut these services
Server addresses and multimedia stored in these
It is very important to always have the information of ADATA
It is complicated.

There is also a fourth problem. In the conventional multimedia communication system, when there are a plurality of servers storing the same multimedia data as the moving picture servers 12 ₁ and 12 ₂ shown in FIG. 5, one of the servers is actually accessed. Without looking at it, it is impossible to determine whether or not the server 12 ₁ or 12 ₂ has exceeded the upper limit of the number of accesses. Therefore, even if there are a plurality of servers that store the same multimedia data, this may cause unnecessary access.

Therefore, the object of the present invention is necessary when the multimedia data is stored in a plurality of servers on the network, without the client knowing what kind of multimedia data is stored in each server. An object is to provide a multimedia communication system capable of accessing multimedia data.

Another object of the present invention is to provide a multimedia communication system capable of surely accessing an accessible server among a plurality of servers when the same multimedia data is stored in the plurality of servers. It is in.

[0016]

According to a first aspect of the invention, (a) a plurality of multimedia data such as moving images, still images, texts, etc., each of which is connected to a network and stores predetermined data A server, (b) one or a plurality of clients that are also connected to the network and access desired ones of multimedia data, and (c) a plurality of servers that are also connected to the network and these are accumulated. A multimedia communication system is provided with a table showing the relationship of multimedia data, and a multimedia data managing means for transferring the contents of this table to the client of the request destination when there is a request from these clients. .

That is, according to the first aspect of the present invention, a multimedia data management means is arranged on the network, and this manages the information regarding the multimedia data of each server. Then, when there is a request from the client, the contents of the table describing the information regarding the multimedia data are returned to the client. This allows
Each client can know what multimedia data is.

According to a second aspect of the invention, the multimedia data managing means notifies the request destination client of the address of each server together with the contents of the table. This allows the client to directly access the specific server according to the desired multimedia data. Of course, as will be described later, it is also possible to request the multimedia data access means to access the multimedia data.

According to the third aspect of the invention, (a) a plurality of servers connected to the network, each of which stores predetermined ones of various multimedia data such as moving images, still images, and text, and (b) One or more clients that are also connected to the network and access the desired ones of the multimedia data, and (c) Addresses of multiple servers that are also connected to the network and the multimedia data stored by them. The multimedia communication system is provided with a multimedia data management means that has a table showing the relationship and requests the corresponding server to transfer the desired multimedia data when these clients request it.

That is, according to the third aspect of the present invention, when the multimedia data management means designates the multimedia data from the client and requests the access, the multimedia data is stored in the server storing the data. The request is made to be transferred to the client. Therefore, each client can obtain the desired multimedia data only by notifying the multimedia data management means of the desired multimedia data without being aware of each server. If the invention described in claim 1 is combined with the invention described in claim 3, each client is shown the contents of multimedia data that can be supplied by the network without knowing the kind and contents of the multimedia data.
It is possible to acquire desired multimedia data without giving any attention to the server by only instructing what is necessary.

According to another aspect of the present invention, the multimedia data management means has an access status grasping means for grasping an access status to each server, an upper limit value storing means for storing an upper limit of the number of accesses of these servers, and a request. Server selection means is provided for selecting a server that has stored the stored multimedia data and does not exceed the upper limit access. That is, claim 3, which is the basis for this.
In the described invention, since the multimedia data managing means accesses the server instead of the client, it is possible to grasp the access status to each server. Therefore, if multiple servers share the same requested multimedia data, select the server that does not exceed the access limit and transfer the multimedia data to the client. You can request to do so. Therefore, it is possible to prevent useless access that occurs when the client individually accesses the server which exceeds the access upper limit value.

According to the invention of claim 5, when the server selecting means cannot select the corresponding server in the multimedia data management means in the invention of claim 4, the multimedia data is transmitted to the client requesting the transfer of the multimedia data. It has been decided to provide a request response means for notifying that transfer of data is impossible. The client who has requested the multimedia data can know that the multimedia data is sent from any server when this notification is not received.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to embodiments.

FIG. 1 shows the configuration of a multimedia communication system according to an embodiment of the present invention. FIG.
The same reference numerals are given to the same portions as, and the description thereof will be appropriately omitted. In the multimedia communication system of this embodiment, a management system 21 is newly connected to the network 11. The management system 21 can also be composed of, for example, a personal computer or a workstation.

FIG. 2 shows an outline of the circuit configuration of this management system. Management system 21 is a CPU
A (central processing unit) 31 is provided. The CPU 31 is connected to each unit in the management system 12 via a bus 32 such as a data bus. Of these, the RAM (random access memory) 33 is a working memory. The disk control circuit 34 is a circuit that controls reading and writing of data from and to the magnetic disk 35. The magnetic disk 35 stores programs for performing various controls of the management system 12, and also stores various kinds of information regarding the moving image servers 12 ₁ and 12 ₂ and the non-moving image server 14. The input circuit 36 is connected to a keyboard 38 to which a mouse 37 as a pointing device is connected,
Various data are input by the operation of the operator. The display control circuit 39 is a circuit that controls the display of the CRT 41. The communication control circuit 42 is connected to the network 11 shown in FIG. 1 via a communication cable 43, receives various requests from the clients 15 ₁ to 15 ₃ and responds to them as necessary. , Video servers 12 ₁ and 12 ₂ and non-video server 14
Among them, the one satisfying the access request is requested to transmit the predetermined multimedia data.

FIG. 3 shows the control operation on the management system side when one of the clients desires to access the multimedia data. Client 15
_When any of ₁ to 15 ₃ desires to access the multimedia data, it makes an information request to the management system 21. The CPU 31 on the side of the management system 21 stands by for the reception of this information request via the communication control circuit 42 (step S101). In the magnetic disk 51, the management system 21 registers the addresses of all the servers 12 ₁ , 12 ₂ , 14 on the network 11 and the type and content information of all the multimedia data stored in them in a table. , Its content has been updated. When the information request is received (Y), the CPU 31 searches this table and retrieves each server 12 on the network 11.
Information on whether ₁ , 12, ₂ and 14 are moving picture servers or non-moving picture servers, and information on what kind of multimedia data they store are requested by a client (hereinafter typically referred to as client 15 ₁ (Denoted as) is transmitted (step S102).

When the client 15 ₁ receives this information, it displays it on its own CRT or a display such as a liquid crystal display, or prints out its contents to search for necessary multimedia data. For non-moving image data, the non-moving image server 1 is used in this embodiment.
Since there is only 4, the corresponding still image, voice, text data or other desired data is designated for the address and transmission is requested. Regarding the moving image data, since there are two moving image servers 12 ₁ and 12 ₂ and it is necessary to transmit in real time as described above, the request is not made directly to the corresponding moving image servers 12 ₁ and 12 ₂ . An access request will be issued via the management system 21.

FIG. 4 shows the control operation of the management system when there is an access request from the client. The CPU 31 of the management system 21 is the client 15
If there is an access request from ₁ (step S201;
Y), the type of desired data sent from the client 15 ₁ is decrypted (step S202). Then, the server that has accumulated the corresponding data is determined from the above-mentioned table (step S203). In the present embodiment, assuming that the access request is accepted only for the moving image data, the CPU 31 determines one of the moving image servers 12 ₁ and 12 ₂ that stores the corresponding moving image data. If both store the corresponding moving image data, one moving image server is determined.

[0030] If this is to be a video server 12 _1,
CPU31 discriminates the access status of the video server 12 _1, made as to whether the discrimination it exceeds the number of upper limit (step S204). This is the type of video data to access, the amount of data, and the video server 1
It is determined according to the situation in which access is decided in 2 ₁ . When the number of accesses does not exceed the upper limit (N), the video server 12 ₁ is requested to transmit the corresponding video data to the client 15 _{1 of the} request destination (step S205). In this way, the client 15 ₁ makes an indirect request by making a request to the management system 21 instead of directly making a request to the corresponding moving image server 12 ₁ for moving image data.

If it is determined in step S204 that the number of accesses to the moving image server 12 ₁ exceeds the upper limit value (Y), it is determined whether another moving image server storing the same moving image data exists. A determination is made (step S2
06). If such a video server (video server 12 _{2 in} this case) exists (Y), step S20.
The video server 12 ₂ is determined as an access destination back to 3. Then, it is checked whether or not the access number exceeds the upper limit of the new moving image server 12 ₂ (step S204). If it does not exceed (N), as described above, the moving picture server 12 ₂ is requested to transmit the corresponding moving picture data to the client 15 ₁ (step S205).

Unlike [0032] above, when the number of accesses video server 12 ₂ even or exceeds the upper limit value, or the other video server storing the same moving image data does not exist (step S206; N), videos Unable to send data. Therefore, the CPU 31 uses the communication control circuit 42 to notify the client 15 _{1 of the} request destination that the moving image data cannot be accessed (step S207). Client 15 ₁ receives the notification,
Either the reception of the corresponding moving image data is abandoned, or the access request is made again to the management system 21 after a predetermined time has elapsed. However, depending on the multimedia communication system, when making an access request to the management system 21,
When the moving image data cannot be accessed, a notification to the effect that the moving image data is to be waited may be given, and the access timing of the moving image data may be left to the management system 21 side. In this case, the management system 21 will notify the corresponding client 15 _{1 that} it is waiting for access. In this case,
It is also possible to notify the predicted time until the start of access.

In the embodiment described above, the management system 21 requests access only via the moving image server, but it is also possible to configure the system so that non-moving image data is also accessed instead. In this case, the management system 21 does not necessarily need to inform the client 15 ₁ that has requested the information of the addresses of the individual servers 12 ₁ , 12 ₂ , and 14. Further, in the present embodiment, there is only one non-moving image server 14, but even if there is a plurality, there is no need to associate the type of data with the corresponding non-moving image server on the client 15 ₁ side. Further, if the upper limit value of the access to the relevant non-video server is exceeded, the management system 21 side can change the access to another non-video server.

[0034]

As described above, according to the first aspect of the present invention, the multimedia data managing means is arranged on the network, and the information related to the multimedia data of each server is managed by the client. I decided to let them know this information when there was. This simplifies the management of multimedia data on the network, and eliminates the need for individual clients to keep track of the multimedia data managed by all servers on the network every time there is a change. There is an advantage that the communication load is reduced. Moreover,
Since each client can obtain information about all multimedia data belonging to the network at a necessary time, these data can be effectively utilized for up-to-date.

According to the second aspect of the present invention, the multimedia data managing means notifies the address of each server to the requesting client together with the contents of the table, so that the client can specify the multimedia data according to the desired multimedia data. Can directly access the server. For example, it is possible to reduce the burden on the multimedia data management means by directly accessing the corresponding server except for the moving image data.

Further, according to the third aspect of the invention, when the multimedia data management means designates the multimedia data from the client and requests the access, the multimedia is stored in the server storing the data. Since the data is transferred to the requesting client, each client only needs to inform the multimedia data managing means of desired multimedia data, and can obtain the data without being aware of each server.

Further, according to the invention described in claim 4, it is decided that the access of these servers does not exceed the allowable limit based on the premise that the multimedia data managing means manages the access of each server. Therefore, useless access can be prevented and the efficiency of network communication can be improved. Also, the client who has made a request for multimedia data can obtain the necessary data from the accessible server side when there are a plurality of servers for the same data, and can ensure quick communication. .

Further, according to the invention described in claim 5, when there are a plurality of servers for the same multimedia data, none of them can be accessed, or only a server exists for the corresponding multimedia data. When the access is not possible, the multimedia data management means gives a notification to that effect, and the requesting client can take prompt action such as selecting other multimedia data by this notification. .

[Brief description of the drawings]

FIG. 1 is a system configuration diagram showing a configuration of a multimedia communication system in an embodiment of the present invention.

FIG. 2 is a block diagram showing an outline of a circuit configuration of a management system of this embodiment.

FIG. 3 is a flowchart showing the control operation on the management system side when any of the clients desires access to multimedia data in the present embodiment.

FIG. 4 is a flow chart showing a control operation of the management system when an access request is made from a client in this embodiment.

FIG. 5 is a system configuration diagram showing an example of a conventional multimedia communication system.

[Explanation of symbols]

11 Network 12 ₁ and 12 ₂ Video Server 14 Non-Video Server 15 ₁ to 15 ₃ Client 21 Management System (Multimedia Data Management Means) 31 CPU 33 RAM 35 Magnetic Disk 42 Communication Control Circuit

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location H04M 11/08 9466-5K H04L 11/20 101B H04N 7/173

Claims (5)

[Claims] 1. A plurality of servers connected to a network and storing predetermined ones of various kinds of multimedia data such as moving images, still images, texts, etc. One or a plurality of clients that access a desired one, and a table that represents the relationship between the plurality of servers that are also connected to the network and the multimedia data accumulated by these servers, and requests from these clients Multimedia data management means for transferring the contents of this table to the client of the request destination when there is a request. 2. The multimedia communication system according to claim 1, wherein the multimedia data management means notifies the request destination client of the address of each server together with the contents of the table. 3. A plurality of servers connected to a network and storing predetermined ones of various kinds of multimedia data such as moving images, still images, texts, and the like. One or a plurality of clients that access the desired one, and a table that shows the relationship between the addresses of the plurality of servers and the multimedia data stored by the plurality of clients that are also connected to the network, and these clients are provided. A multimedia communication system, comprising: a multimedia data management means for requesting the transfer to a corresponding server when a desired multimedia data is requested from the server. 4. The multimedia data management means includes access status grasping means for grasping an access situation to each server, upper limit value storing means for storing the upper limit of the number of accesses of these servers, and requested multimedia data. 4. The multimedia communication system according to claim 3, further comprising: a server selecting unit that selects a server that has not been accessed more than an upper limit value among the stored servers. 5. When the server selecting means cannot select the corresponding server, the requesting means for notifying the client, which has requested the transfer of the multimedia data, that the transfer of the multimedia data is impossible. The multimedia communication system according to claim 4, characterized in that