JP2004048782A - Information management system, server computer, and computer readable recording medium with program for server recorded thereon - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To synchronously control the streaming contents which can be reproduced at an arbitrary time, and the other contents. <P>SOLUTION: When an acquisition request of distribution information 2bb is outputted from an information reading means 1a, a request relay means 1c compares the contents of a server side control file 2ba with contents of a local side control file 1ba to determine the information to be acquired. When acquiring the streaming contents from a server computer 2, in a local computer 1, an acquisition request of information defined in a synchronism file with synchronism reference time sent from a streaming server as a reference is outputted synchronously with the streaming contents. As a result, the information defined in the synchronism file is acquired in accordance with the progress conditions of the streaming contents. <P>COPYRIGHT: (C)2004,JPO

Description

The present invention relates to an information management system, a server computer, and a computer-readable recording medium on which a server program is recorded, and more particularly to an information management system, a server computer, and a server program for handling information distributed via a network. The present invention relates to a computer-readable recording medium.

In recent years, due to the rapid spread of the Internet, a plurality of servers have been started in server computers, and countless HTML (Hyper Text Markup Language) texts, JPEG (Joint Photographic Experts Group) files, GIF (Graphics Interchange Format) files, audio files Are provided to many users. Here, image files and audio files such as JPEG have a larger file size than text, and it takes time to transmit the files. Therefore, the transmission amount of the line has increased dramatically, and the load on the line has become excessive.

To avoid such line congestion, cached content once accessed is stored on a local medium (such as a hard disk device). Thus, when the cached content is accessed again, the content can be read from the local medium, and the transmission amount of the communication line can be reduced.

It should be noted that other techniques regarding the same data transfer amount reduction have been considered (for example, see Patent Literature 1, Patent Literature 2, and Patent Literature 3).
JP-A-6-332858 JP-A-63-291142 JP-A-59-94155

However, the method of caching contents has a problem that the first access always requires transfer from the server. Also, the storage of cache data usually has a time limit, and access after that time is also affected by the transmission capacity of the transmission path.

By the way, some Internet contents are updated on a daily basis, but some do not need to be updated for a certain period of time. For example, content such as a participant's roster for a meeting does not often need to be updated from the time the meeting is decided to be held and participants until the end of the meeting. In addition, if the meeting is such that only a specific member participates, it is sufficient that only the member can browse the contents related to the meeting.

Therefore, it is conceivable to record specific contents in a CD-ROM (Compact Disk Read Only Memory) and distribute it to those who need it. However, in this case, when the content is recorded on the medium, the link relationship between the content must be rewritten. That is, when the HTML file exists on the server, a URL (Uniform Resource Locator) of the designated file on the server is assigned to the designation of the link destination, the designation of the image file to be displayed inline, and the like. Therefore, in the case where the file including the link destination file and the image file to be displayed inline is stored in the CD-ROM, the location of the specified file is a local medium. To access the link destination as a local medium, it is necessary to rewrite the URL specification to a local name. Performing this operation for all HTML files is a very difficult operation.

Also, in order to distribute streaming content, an image according to the progress may be displayed on the screen by synchronous control. For example, there is a case where audio is distributed by streaming and an image is displayed on the client according to the progress of the audio. Conventionally, a synchronization file is stored in a streaming server, and when a streaming playback player plays back streaming content, a corresponding synchronization file is acquired from the streaming server. In the synchronization file, which image is to be opened in which time zone based on the time when the reproduction of the streaming content is started is specified. In this way, it is possible to display an image suitable for the reproduced content of the streaming content on the WWW browser while synchronizing the image.

However, in the conventional synchronous control technology, it is assumed that the playback content is the same no matter when the playback of the streaming content is started. Not applicable to possible streaming content.

The present invention has been made in view of such a point, and an information management system, a server computer, and a computer recording a server program capable of controlling synchronization between streaming content that can be reproduced at an arbitrary time and another content It is an object to provide a readable recording medium.

According to the present invention, an information management system as shown in FIG. 1 is provided to solve the above problems. In an information management system for managing information distributed from a server computer 2 to a local computer 1 via a network, the server computer 2 registers distribution information 2bb to be distributed via the network and attribute information of the distribution information. Distribution information storage means 2b for storing the stored server-side control file 2ba, and a streaming content acquisition request for distributing the information stored in the distribution information storage means 2b in response to a request and changing the content in accordance with time. Is received, a synchronization file defining information to be synchronized with the streaming content and a synchronization reference time serving as a reference for displaying information defined in the synchronization file are transmitted together with the streaming content. And a server 2a. A local computer file 1ba in which the copy information 1bb of the distribution information 2bb in the distribution information storage means 2b and the attribute information of the copy information 1bb are registered; Upon receiving a request to acquire the distribution information 2bb stored in the distribution information storage means 2b, the server-side control file 2ba and the local-side control file 1ba are acquired, and the attribute information of the requested distribution information 2bb is obtained. Request relay means 1c for comparing attribute information of the copy information 1bb corresponding to the distribution information 2bb and determining information to be obtained based on the comparison result; outputting a request for obtaining the streaming content; Plays back the streaming content returned and sends it from the streaming server. Streaming content playback means for outputting, in synchronization with the streaming content, a request to acquire information defined in the synchronization file with reference to the synchronization reference time thus obtained. Provided.

According to such an information management system, when a request to acquire the distribution information 2bb is issued from the information browsing means 1a to the request relay means 1c, the request relay means 1c stores the contents of the server-side control file 2ba and the local-side control file 1ba. And determine the information to be obtained. When acquiring the streaming content from the server computer 2, the local computer 1 synchronizes a request for acquiring information defined in the synchronization file with reference to the synchronization reference time sent from the streaming server with the streaming content. Output. As a result, less information needs to be acquired from the server computer, and the operation on the information browsing means 1a side is the same as when accessing the server computer 2, and there is no change in the operation procedure. Also, information defined in the synchronization file can be acquired according to the progress of the streaming content.

As described above, in the present invention, the copy information of the distribution information is stored in the local computer, and the request for obtaining the distribution information in the server computer is received by the local proxy server to determine appropriate information. Thus, the amount of information transmitted to and from the server computer can be reduced.

When acquiring streaming content from the server computer, the local computer outputs an acquisition request for information defined in the synchronization file based on the synchronization reference time sent from the streaming server in synchronization with the streaming content. Therefore, the information defined in the synchronization file can be acquired according to the progress of the streaming content.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram showing a basic content acquisition method according to the embodiment. In the following embodiment, a local computer 1 and a server computer 2 are connected to each other via a network.

The server computer 2 stores the distribution information 2bb to be distributed via the network and the server-side control file 2ba in which the attribute information of the distribution information 2bb is registered, and the distribution information storage means 2b. And a server 2a that distributes the requested information in response to a request.

In the local computer 1, the copy information 1bb of the distribution information 2bb in the distribution information storage means 2b, the position information when the copy information 1bb exists in the distribution information storage means 2b, and the attribute information of the copy information 1bb are registered. Upon receiving a request to acquire the copy information storage means 1b storing the local control file 1ba and the distribution information 2bb stored in the distribution information storage means 2b, the server side control file 2ba and the local control file 1ba are acquired, Request relay means 1c for comparing attribute information of requested distribution information 2bb with attribute information of copy information 1bb corresponding to distribution information 2bb, and determining information to be obtained based on the comparison result; I have.

In such an information management system, when a request to acquire the distribution information 2bb is issued from the information browsing unit 1a to the request relay unit 1c, the request relay unit 1c receives the request and analyzes the content. Then, the server-side control file 2ba managed by the requesting server 2a and the local-side control file 1ba in the copy information storage unit 1b are acquired. Here, it is confirmed whether or not the requested information is stored in the copy information storage means 1b. If the requested information is stored, the version of the copy information 1bb in the copy information storage means 1b is further updated. Judge whether or not. If the corresponding information exists in the copy information storage unit 1b and the version number is the latest, the information is extracted from the copy information storage unit 1b. Otherwise, the distribution information 2bb is extracted from the server computer 2.

Thus, the information acquired from the server computer 2 can be reduced, and the operation on the information browsing unit 1a side is the same as the case of accessing the server computer 2, and there is no change in the operation procedure.

(4) A greater effect can be obtained by applying the content acquisition method shown in FIG. 1 to a wide area network such as the Internet. On the Internet, the server 2a may be a WWW server or a streaming server. The information browsing means 1a corresponds to a WWW browser.

Hereinafter, an embodiment of the present invention will be described with reference to an example of browsing HTTP content and reproducing streaming content. Here, the streaming is a content that is temporally and continuously transferred in order to download and play back multimedia data such as audio and video. Note that streaming data is transferred after being divided into unit information, and the unit information is called a clip.

In the following description, a basic data transfer method will be described first, and then a method for controlling synchronization of streaming content will be described.
FIG. 2 is a configuration diagram of the data transfer function according to the embodiment of the present invention. As shown, the local computer 10 and the server computer 20 are connected via the Internet 30.

The local computer 10 includes a WWW browser 11, a streaming playback player 12, a local proxy server 13, and an auxiliary storage device 14.
The WWW browser 11 outputs a request to the server computer 20 via the local proxy server 13. For this purpose, an external proxy server setting function provided in a general WWW browser is used. That is, in the WWW browser 11, the setting of the proxy server is set to “localhost (IP address = 127.0.0.1)”. As a result, a proxy server (here, the local proxy server 13) in the local computer 10 on which the WWW browser 11 is operating is designated, and the request from the WWW browser 11 can be relayed by the local proxy server 13. it can.

The streaming playback player 12 issues a request to the streaming server 22 in response to a request from the WWW browser 11, and plays back the returned streaming content.
The local proxy server 13 relays a request output from the WWW browser 11 to the server computer 20. Then, the control files 14a and 24a of the requested content are obtained from both the server computer 20 and the auxiliary storage device 14. Based on the acquired control files 14a and 24a, it is determined whether or not the streaming content 14c in the auxiliary storage device 14 is the latest one. If the streaming content 14c is the latest content, the streaming content is read from the auxiliary storage device 14, Otherwise, the streaming content 24b stored in the server computer 20 is obtained via the Internet 30.

The auxiliary storage device 14 is a portable recording medium such as a CD-ROM and a device for reading data from the medium. The recording medium stores a control file 14a, HTTP content 14b, and streaming content 14c. The control file 14a is a file having information such as the version number of the HTTP content 14b and the streaming content 14c and the storage location of the original content. The HTTP content 14b and the streaming content 14c are obtained by directly copying the HTTP content 23b and the streaming content 24b stored in the server computer 20 in the past.

The server computer 20 is provided with a WWW server 21 and a streaming server 22, and has databases 23 and 24, respectively. The database 23 stores a control file 23a and HTTP contents 23b, and the database 24 stores a control file 24a and streaming contents 24b.

The WWW server 21 returns the control file 23a and the HTTP content 23b in the database 23 in response to a request from the local computer 10. The streaming server 22 returns a control file 24a in the database 24 in response to a request from the local computer 10, and returns streaming content 24b in response to a request from the streaming playback player 12 of the local computer 10.

FIG. 3 is a diagram showing a network model of the present system. The local computer 10 and the server computer 20 are connected to the Internet 30 by physical layers 15 and 25. An Internet layer {IP (Internet Protocol) layer # 16, 26 is constructed above the physical layers 15, 25. The transport layers 17, 18, 27, 28 are constructed on the upper layer. The transport layers 17 and 27 are TCP (Transmission Control Protocol) layers, and the transport layers 18 and 28 are UDP (User Datagram-Protocol) layers.

The WWW browser 11 and the local proxy server 13 on the local computer 10 are application layers above the transport layer 17 of TCP. The streaming playback player 12 is an application layer above the UDP transport layer 18. On the other hand, the WWW server 21 of the server computer 20 is an application layer above the transport layer 27 of TCP, and the streaming server 22 is an application layer above the transport layer 28 of UDP.

Here, the WWW browser 11 and the streaming reproduction player 12 transmit and receive data to and from the corresponding servers. The basic procedure is shown below.
FIG. 4 is a diagram showing a data flow between the client and the server. First, an HTTP request (GET, PUT, etc.) is issued from the WWW browser 11 to the WWW server 21 by TCP.

As a general example, assuming that a user designates “URL = http: //fujisan.gmsnet.ro.jp/hylintk/kanda.html” as the WWW browser 11 and starts it, the request to the WWW server 21 is , "GET http://fujisan.gmsnet.ro.jp/hylintk/kanda.html".

Then, the WWW server 21 extracts the requested HTML file from the HTTP content 23b, adds header information to the file, and sets the file as response data 41. The WWW server 21 returns the response data 41 to the WWW browser 11. The following contents are described in the response data 41.

FIG. 5 is a diagram showing the contents of the response data. Header information is added to the beginning of the response data 41, and the content of the content is described in HTML following the header information. In the header information, MIME (Multipurpose Internet Mail Extension) information is indicated by “content-type”.

A MIME table 11a is prepared in the WWW browser 11. Registered in the MIME table 11a are MIME (HTML, JPEG, GIF, etc.) that can be processed by itself and MIME that can be processed by a helper application or a plug-in application. Then, the WWW browser 11 receiving the response data 41 determines from the MIME table 11a whether it can be treated by itself or is processed by another application. If the content can be processed by itself, the WWW browser 11 itself processes the content, but if the content is processed by another application, the corresponding program is started. At the time of activation, the contents of the content are passed as a parameter to the program.

Here, there is a case where the WWW browser 11 requests streaming content. In this case, the user specifies “URL = http: //fujisan.gmsnet.ro.jp/hylintk/01audio/hylintk1a.ram”. “Hylintk1a.ram” specified by this URL is a metafile with the contents “pnm: //fujisan.gmsnet.or.jp/hylintk/01audio/hylintkla.ra”. Here, the meta file refers to an intermediate file for the WWW browser 11 to start the streaming playback player 12. In the contents, the URL of the streaming content to be reproduced is described. When such designation is made, the WWW browser 11 sends a request "GET http://fujisan.gmsnet.ro.jp/hylintk/01audio/hylintk1a.ram" to the WWW server 21. The WWW server 21 returns the following response to this request.

FIG. 6 is a diagram showing an example of response data to a request for streaming content. In the response data 41b, "audio / x-pn-realaudio" is indicated as "context-type".

Since the “audio / x-pn-realaudio” has been passed as the MIME, the WWW browser 11 looks up the MIME table 11a and searches for a corresponding application. Then, the corresponding application is started. At this time, the content of the content passed from the WWW server 21 is passed to the application as a parameter. In this example, the streaming playback player 12 is activated, and “pnm: //fujisan.gmsnet.or.jp/hylintk/01audio/hylintkla.ra” is passed as a parameter.

(4) The started streaming playback player 12 issues a GET request to the streaming server 22 with the received parameter as a URL. The streaming server 22 sends the requested content 42 to the streaming playback player 12 in compressed data units of clips 42a to 42c. The streaming reproduction player 12 expands the transmitted clip and reproduces sound / video.

The above is the procedure for accessing the HTTP content and the streaming content on the server computer 20.
Here, if the HTTP content 23b or the streaming content 24b does not need to be updated for a certain long period of time, the content can be stored in the auxiliary storage device 14 in the local computer 10. To do so, the HTTP content 23b and the streaming content 24b are directly copied to a CD-ROM. At this time, the control file 14a for the local computer 10 is also stored in the CD-ROM. Then, the created CD-ROM is distributed to users of the local computer 10. The user inserts the distributed CD-ROM into the CD-ROM drive of the local computer 10. As a result, the auxiliary storage device 14 as shown in FIG.

{Circle around (2)} In the server computer 20, a control file 23a for the HTTP content 23b and a control file 24a for the streaming content 24b are created and stored in the databases 23 and 24, respectively.

FIG. 7 is a diagram showing an example of a control file of the local computer. In this example, the control file 14a is composed of a plurality of files centered on the centralized file 14aa. Here, the control file name refers to the file name of the centralized file 14aa.

(4) The version of the file is indicated in the overall file 14aa. Next, a set of a “host name”, a “document base directory name”, a “server side control file name”, and a plurality of “management file name list files” is registered for each server.

ＩＰA corresponding IP address is also added to the “host name”. The “document base directory name” indicates a basic directory for specifying a file in the server computer. “Server-side control file name” indicates the name of a control file provided on the server computer. As the control file name, the file name of the control file on the server computer side is used.

The management file name list file 14ab is provided for each content. The version, path (path from the document base directory to the directory where the corresponding file exists), and file name of the corresponding content (HTTP content 14b, streaming content 14c) are shown. If there is an image to be displayed inline in the HTML file, the path and file name of the image file are also included.

FIG. 8 is a diagram showing a control file on the server computer side. The control file 23a on the server computer 20 side is also a set of the supervision file 23aa and the management file name list file 23ab.

(5) The version of the file is indicated in the overall file 23aa. Next, a set of a “host name”, a plurality of “document base directory names”, and a plurality of “management file name list files” is registered. The contents of the management file name list file 23ab are the same as those of the management file name list file 14ab (shown in FIG. 7) on the local computer 10 side.

Here, a processing procedure when a request is output from the WWW browser 11 will be described. The request from the WWW browser has the content of “(command) / (protocol): // (host name) / (base path name) / [(path name /)] file name”. The command for acquiring the content is “GET”. When accessing the WWW server 21, the protocol is designated as "http", and when accessing the streaming server, the protocol is designated as "pnm".

FIG. 9 is the first half of a flowchart showing the processing procedure of the local proxy server. The following processes are all performed by the local proxy server 13.
[S1] The information held in the previous processing is initialized.

[S2] It is determined whether there is a communication request from the WWW browser 11. If there is a request, the process proceeds to step S3, and if there is no request, this process is repeated.
[S3] It is determined whether the recording medium is in a readable state (ready). If readable, the process proceeds to step S4, and if not, the process proceeds to step S22.

[S4] The control file 14a is obtained from the recording medium. In the example of FIG. 7, the control file 14aa and the management file name list file 14ab are acquired.
[S5] It is determined whether or not the acquisition was successful. If the file has been acquired normally, the process proceeds to step S6. If the file cannot be found or a reading error has occurred, the process proceeds to step S22.

[S6] All sets of the host name and the document base directory name are acquired from the acquired control file 14a.
[S7] A local file list is created. Specifically, a set of a path name and a file name is extracted from all the management file name list files 14ab, and these are listed.

[S8] It is determined whether the host name included in the request from the WWW browser 11 is registered in the control file 14a. If registered, the process proceeds to step S9. If not registered, the process proceeds to step S22.

[S9] It is determined whether the base path name included in the request from the WWW browser 11 matches the document base directory name registered corresponding to the host name detected in step S8. If the base path names match, the process proceeds to step S10, and if not, the process proceeds to step S22.

[S10] Based on the local file list, the path names and file names in all the management file name list files registered under the set of the host name and the document base directory name detected in steps S8 and S9. Is determined, and it is determined whether or not there is one corresponding to the pair of the path name and the file name included in the request from the WWW browser 11. If there is a corresponding file, the process proceeds to step S11. If there is no corresponding file, the process proceeds to step S22.

[S11] The server-side control file name corresponding to the set of the host name and the base path name detected in steps S8 and S9 is extracted from the control file 14a, and the control file is obtained from the corresponding server.

FIG. 10 is the latter half of the flowchart showing the processing procedure of the local proxy server.
[S12] It is determined whether the control file on the server side has been normally acquired. If the file has been successfully obtained, the process proceeds to step S13. If the file cannot be obtained due to disconnection of the line, the process proceeds to step S16.

[S13] A server-side file list is created based on the server-side control file. The content of the server-side file list is a set of pairs of a path name and a file name of the content managed by the server.

[S14] Based on the server-side file list, it is determined whether or not there is one corresponding to the pair of the path name and the file name included in the request from the WWW browser 11. If there is a corresponding file, the process proceeds to step S15, and if there is no corresponding file, the process proceeds to step S22.

[S15] The version number of the file detected in step S10 is compared with the version number of the file detected in step S14 to determine whether the server-side file is newer. If the file on the server side is newer, the process proceeds to step S22; otherwise, the process proceeds to step S16.

[S16] The corresponding file is acquired from the auxiliary storage device 14.
[S17] It is determined whether the data has been acquired normally. If it can be obtained normally, the process proceeds to step S18. If it cannot be obtained normally, the process proceeds to step S22.

[S18] It is determined whether the obtained file is a metafile. If it is a metafile, the process proceeds to step S19, and if it is not a metafile, the process proceeds to step S23.
[S19] It is determined whether the host name in the metafile is registered in the control file 14a. If registered, the process proceeds to step S20. If not registered, the process proceeds to step S23.

[S20] It is determined whether the base path name in the metafile matches the base path name registered corresponding to the host name detected in step S19. If the base path names match, the process proceeds to step S21; otherwise, the process proceeds to step S23.

[S21] Convert the contents of the metafile. Specifically, the protocol is changed to “file”, and the host name and the base path name are changed to names indicating the auxiliary storage device 14. For example, if the metafile is “pnm: //fujisan.gmsnet.or.jp/hylintk/01audio/hylintkla.ra”, change the content to “file: d: /hylintk/01audio/hylintkla.ra”. In this example, the auxiliary storage device is recognized by the local computer 10 as the drive name “d”. After this processing ends, the flow proceeds to step S23.

The conversion process in step S21 is a process that is necessary because the request is relayed by the local proxy server in the application layer. Therefore, if the request is relayed in a layer lower than the application layer, there is no need for the conversion processing as shown in step S21.

[S22] Content is acquired from the server.
[S23] Header information is added to the acquired data, and the data is returned to the WWW browser 11.
In this manner, the content can be obtained from the HTTP content 14b or the streaming content 14c stored in the auxiliary storage device 14. In the case of a streaming content, since the file content has been changed in step S21, all subsequent requests from the streaming playback player 12 are made to the streaming content 14c in the auxiliary storage device 14. As a result, reading can be performed at high speed without being affected by the transmission capacity of the transmission path.

Further, since there is no need to change the content of the content stored in the auxiliary storage device 14, a CD-ROM to be distributed to the user of the local computer 10 can be easily created. Further, since the user using the WWW browser 11 only needs to output a request in accordance with the procedure for acquiring the target content from the server, there is no change in the operability of the user.

The content once obtained can be recorded by the local proxy server 13 as cache data on a local writable recording medium such as a hard disk device. In this case, an extended control file is generated, the cached content is managed by the extended control file, and the path to the extended control file (including the drive name) and the file name of the extended control file are stored in the integrated file 14aa. register. The extended control file also includes a supervision file and a management file name list file. The contents of the management file and the management file name list file generated at this time are the same as those constituting the server-side control file.

As described above, by simultaneously caching the content, the data that must be acquired via the network can be further reduced.
When the local computer 10 is provided with a caching function, it is also possible to download the latest information of the server computer 20 collectively. To do so, when the local control file and the server control file are acquired, the versions of all corresponding contents are compared. Then, all the contents determined to be newer on the server side are acquired and stored in the local recording medium. This allows the local computer 10 to handle the latest contents even when the local computer 10 is used after the line is disconnected.

Furthermore, the access order (priority) of the contents can be specified. This access order is specified in the local control file. Then, when the local proxy server 13 receives the request from the WWW browser, the local proxy server 13 checks whether or not the content exists in the specified order. Then, the previously detected content is set as an access target (in this case, the version numbers are not compared). For example, an access order such as “extended local (content cached on a writable recording medium) → reference local (content previously stored on a CD-ROM) → server (content acquired via a network)” is designated. If this is done, the latest information on the server computer 20 side is collectively downloaded, so that subsequent access to the server computer 20 becomes unnecessary including acquisition of the control file.

Also, it may be possible to specify the super version number that is always regarded as the maximum value. The version number of the supermarket means that the version number comparison is unnecessary, and the content in which the version number is set should be accessed with the highest priority. For example, if the version number is “00”, the local proxy server 13 considers the version number of the content as the maximum value. By defining the super version in this way, complicated version management (management is complicated when there are multiple versions of content when server-side content is changed periodically) And control can be simplified. For example, if a super version number is set in the difference file, it is always recognized as the latest content, and content management is easy. It can also be used to specify the priority of the content. For example, the content on the local side is set to the super version number, and the content is only the summary. On the server side, the content is managed by the conventional version number management.

By the way, the server computer 20 and the local computer 10 do not necessarily have the same OS (Operating System) as a platform. Different platforms have different naming conventions for directory and file names. Therefore, the naming rules that can be used on each platform are classified by type, and a file type identifier is set for each group. By registering a file type identifier corresponding to the host name in the control file, a directory name or a file name that can be handled by each host can be specified.

Also, different servers often have the same base directory name. In this case, if both contents are to be stored in the auxiliary storage device of the local computer 10 as they are, the storage locations are duplicated. Therefore, one content is stored in another place. At this time, conversion information indicating the correspondence between the position information (path) of the place that should have been originally stored and the position information (path) of the place actually stored is stored in the control file of the local computer 10. . The local proxy server 13 can correctly access the content stored in another location in the auxiliary storage device based on the conversion information.

For example, "http://ashitaka.gmsnet.or.jp/r-pro/index.html" and "http://fujisan.gmsnet.or.jp/r-pro/index.html" are used as auxiliary storage devices. , Each content is stored as "\ r-pro \ index.html" and "\ r-pro1 \ index.html". And the supervision file of the local computer 10 includes
HOST = "ashitaka.gmsnet.or.jp"
BASE (01) = "r-pro"
And
HOST = "fujisan.gmsnet.or.jp"
BASE (01) = "r-pro"
RENAME = "r-pro1"
Is included. Here, “HOST” indicates a host name, “BASE” indicates a document base directory, and “RENAME” indicates position information of a conversion destination. Thus, when the “http://ashitaka.gmsnet.or.jp/r-pro/index.html” is requested from the WWW browser, the local proxy server 13 sets “\ r-pro \ index. html ", and when" http://fujisan.gmsnet.or.jp/r-pro/index.html "is requested," \ r-pro1 \ index.html "can be accessed.

{Circle around (2)} After the information to be stored in the local computer 10 is created, the structure may be changed by moving the position of the content file or changing the name on the server side. In this case, file structure change information is set in the server-side supervision file. That is, the directory and the file name after the change are associated with the directory and the file name before the change. Thereby, the local proxy server 13 that has acquired the server-side control file can recognize the correspondence between the local-side content and the file based on the file information after the structure change based on the file information before the structure change. Thus, access to the corresponding server-side content becomes possible.

In addition, in the centralized file on the server side, it is possible to set to prohibit a specific file from being held as cache data. As described above, when the local proxy server 13 acquires a file prohibited to be held as cache data, the content of the file is passed to the WWW browser, but is not stored in the hard disk device. This makes it possible to prevent illegal copying on the local computer 10.

Further, in the above example, the case where the copy of the content stored on the server side is brought into the auxiliary storage device of the local computer 10 has been described, but the complete copy of the content stored on the server side is not necessarily completed. Need not be. For example, the server stores image data having a low resolution, stores clear image data corresponding to the image data in a CD-ROM or the like, and inserts the image data into a CD-ROM drive of the local computer 10. It may be. In this case, instead of comparing the version numbers, the local proxy server 13 may compare the information of the resolution of the image data and acquire the higher resolution. As a result, when the corresponding data is stored in the local computer 10, high-quality data is obtained, and when the data can be obtained only via the network, low-quality data is obtained. This makes it possible to reduce the amount of data transmitted when referring to an image via a network.

Also, as long as the corresponding content exists in the auxiliary storage device, if the content is always obtained from the auxiliary storage device 14, the data obtained via the network can be further reduced.

Next, a technology for synchronizing streaming contents will be described. In the present embodiment, the synchronization control between the streaming content and another content (for example, a still image) is reliably performed.

Here, the synchronization control that has been performed conventionally will be described. Synchronous control is used when, for example, displaying an image according to the progress of the streaming content on a screen when reproducing the streaming content. At this time, the streaming content is transmitted from the streaming server, and the image is transmitted from the WWW server. Therefore, it is necessary to synchronize these data.

Therefore, conventionally, a synchronization file is conventionally stored in a streaming server, and when a streaming playback player plays back streaming content, a corresponding synchronization file is obtained from the streaming server. In the synchronization file, which image is to be opened in which time zone based on the time when the reproduction of the streaming content is started is specified.

FIG. 11 is a diagram illustrating an example of a synchronization file. As shown in the figure, a plurality of display start times and a plurality of display end times of a JPEG image file are set.
The streaming playback player that has acquired such a synchronous file performs time monitoring based on the time at which the playback of the simultaneously acquired streaming content has started. Then, while requesting / retrieving / reproducing a clip of the streaming content, when the start time indicated in the synchronization file is reached, a request to display the content is made to the WWW browser based on the related URL. The WWW browser outputs a request for the corresponding image file to the WWW server based on the received URL, and receives the corresponding content. The received content is displayed on the screen of the display device of the client computer.

(5) In this way, it is possible to display an image suitable for the reproduction content of the streaming content on the WWW browser while synchronizing the image. However, according to the conventional technology, it is assumed that the playback content is the same regardless of when the playback of the streaming content is started, and thus cannot be applied to, for example, a case where a live broadcast is performed via the Internet.

Here, the live broadcast means that “the streaming content is distributed only during the absolute time zone (for example, January 28, 1998 @ 8:00 pm to 8:30 pm), and is reproduced only at the time within the time zone. The distribution form of the streaming content, such as "can do". It should be noted that there are two realization methods for live broadcasting. The first is a method in which previously recorded content is played only during that time zone. The second is a method of playing live recorded audio only during that time in a real live broadcast.

(4) When a live broadcast is played by the first method, since the streaming playback player processes the origin of the synchronization time axis as 0, an image displayed synchronously is shifted depending on the time when the player is started.

FIG. 12 is a diagram for explaining a shift of the synchronization time axis. As shown in the figure, if the streaming content is reproduced on a time axis that is correctly synchronized, an appropriate image is displayed at the time intended by the content provider. For example, when playing music, an image image corresponding to the tune is displayed.

However, if the time for reproducing the streaming content is delayed, the time for displaying the image is also delayed. For example, if the reproduction of the streaming content is started 5 minutes after the start of the live broadcast of the music, the music is reproduced from the middle, but the images and the like are displayed based on the reproduction start time. Therefore, all images to be displayed in synchronization are displayed with a delay of 5 minutes from music.

As a solution, there is a method of returning the elapsed time T1 from the start of the live performance from the streaming server to the local computer when a request is made from the streaming reproduction player. The streaming playback player that has received the elapsed time T1 passes the related URL to the WWW browser on the basis of the time that is earlier than the own time by T1. As a result, it is possible to eliminate the difference in the reproduction start time of the streaming reproduction player.

同期 In addition, synchronization control can be performed by the streaming server to eliminate the synchronization error. In that case, it is necessary to pass the clip of the streaming content and the related information to the streaming playback player in some way. One example is a method of embedding related URL information in a clip. Such an example will be described below as a first embodiment.

FIG. 13 is a configuration diagram of the synchronization function of the streaming content according to the first embodiment of the present invention. In this embodiment, the amount of data to be transmitted is reduced by using the technique described in the first embodiment.

The local computer 50 has a WWW browser 51, a streaming playback player 52, a local proxy server 53, and an auxiliary storage device 54. Among them, the WWW browser 51, the local proxy server 53, and the auxiliary storage device 54 have the same functions as the elements having the same names described in FIG. Note that the auxiliary storage device 54 stores a still image 54a in advance. The HTTP server 60 provides a still image 61 via a network. The streaming server 70 has streaming content 71 and a synchronization file 72 corresponding to the content. The synchronization file 72 is stored in the same directory as the streaming content 71, and the file name of the synchronization file 72 is different from the streaming content 71 only in the extension. Therefore, the synchronization file 72 corresponding to the streaming content 71 can be easily found.

In such a system, when the WWW browser 51 of the local computer 50 acquires the metafile specifying the streaming content 71, the streaming playback player 52 is activated and the content of the metafile is passed. The streaming reproduction player 52 outputs a request for acquiring the streaming content 71 to the streaming server 70.

When the predetermined time comes, the streaming server 70 divides the streaming content 71 to create the compressed data 81, and extracts the related URL 82 to be synchronized with the compressed data 81 from the synchronization file 72. Basically, only the compressed data 81 is distributed as a clip to all the local computers that have issued the acquisition request. At this time, the streaming server 70 manages the time from the start of content transmission while referring to the synchronization file 72 corresponding to the streaming content 71. Then, when the time specified as the start time in the information in the synchronization file 72 has come, the related URL 82 is combined with the compressed data 81 to generate a clip 80, and the clip 80 including the URL of the content to be synchronized is transmitted to the local computer 50. Send out.

The clip 80 transmitted by the streaming server 70 is received by the streaming reproduction player 52. The streaming playback player 52 decompresses and plays back the compressed data 81 in the clip 80 and, when the related URL 82 is included, passes the related URL 82 to the WWW browser 51. The WWW browser 51 passes the request for the related URL 82 to the local proxy server 53. If the latest still image of the designated URL is stored in the auxiliary storage device 54, the local proxy server 53 acquires the still image 54a from the auxiliary storage device 54. Otherwise, a still image 61 is obtained from the HTTP server 60. The still image 51a acquired by the local proxy server 53 is passed to the WWW browser 51 and displayed on the screen.

In this way, the streaming server 70 manages the synchronization file 72 and includes the related URL in the clip of the streaming content 71, so that no matter when the streaming content is requested from the local computer 50, the playback content and the related information can be compared. The correspondence does not shift.

By the way, when delivering live live broadcasts instead of pre-recorded content, things often do not go according to schedule. Therefore, a synchronization file cannot be created in advance.

Therefore, in the case of live broadcasting, a related URL of a still image according to the progress of the live is generated as needed and combined with the compressed data. As a result, the synchronization control can be performed correctly even for live live broadcasting.

If such live synchronization control technology is used, a plurality of live encoder contents can be centrally managed and all contents can be reproduced while being synchronized.
In other words, if the streaming server does not have a synchronization control function as in the past, if the sound of instruments played in various places around the world is centrally managed by the streaming server and a live orchestra broadcast is performed, Are concentrated, and therefore, any one of the packets always has a delay due to the collision of the packets. In the case of an orchestra performance, even a slight time lag can be very difficult to hear.

Therefore, as a second embodiment, a system will be described in which a delay time can be corrected by providing a streaming server with a content buffering function.
FIG. 14 is a configuration diagram of the second embodiment of the present invention. The streaming server 90 acquires live performance information from the plurality of live encoders 111 to 113 and distributes the information to the plurality of streaming playback players 120 while maintaining synchronization.

The live encoder 111 records the sound of the piano 101 and sends it to the streaming server 90. The live encoder 112 records the sound of the guitar 102 and sends it to the streaming server 90. The live encoder 113 records the sound of the drums 103 and sends it to the streaming server 90.

The file 92 in which the bass sound is recorded is stored in the streaming server 90 in advance. The sounds of the live encoders 111 to 113 are temporarily stored in the corresponding files 93 to 95. In addition, source control information 96 that defines a performance time zone of each sound source is provided in advance.

{The format of the source control information 96 is “source URL, start time, end time, {, synchronous URL}”. Note that the synchronization URL is used when synchronizing with an image or the like as described in the second embodiment.

FIG. 15 is a diagram illustrating an example of the source control information. This example is the source control information 96 for controlling the performance for three minutes in total. The description after “;” is merely a comment.
Here, the streaming server 90 manages the time axis with the timing at which the conductor instructs to start playing as the origin. The data sent from each of the live encoders 111 to 113 is buffered in files 93 to 95, and the start and end times are adjusted according to the source control information. As a result, integration and distribution can be executed completely in synchronization.

FIG. 16 is a diagram showing a performance result based on the source control information of FIG. Thus, the performance starts at the time specified by the source control information 96 and ends at the established time.
If the number of streaming playback players requesting information is large, an overhead problem of managing individual streaming data in the server occurs. In that case, the source control information may be passed to the streaming playback player. The streaming playback player that has received the source control information has a sound synthesis processing unit (a sound synthesis distribution processing unit of the streaming server without the distribution function) and a file for buffering each streaming data. Need to be. If the live performance has already been started when the streaming playback player outputs the request, the elapsed time from the start of the performance is transmitted from the streaming server to the streaming playback player. This eliminates a delay due to a shift at the start of reproduction.

Note that the above example shows an example of live broadcasting of live performance, but it is also possible to control recorded streaming content.
If the sound data is a MIDI (Musical Instrument Digital Interface) file, sound synthesis is easy. Therefore, the above embodiment is a particularly effective means for live broadcasting using a MIDI file.

The processing contents of the functions that each computer should have can be described in a program recorded on a computer-readable recording medium. By executing this program on a computer, the above processing is realized by the computer. Computer-readable recording media include magnetic recording devices and semiconductor memories. When distributing in the market, the program is stored and distributed in a portable recording medium such as a CD-ROM or a floppy (registered trademark) disk, or stored in a storage device of a computer connected via a network. It can also be transferred to another computer over a network. When the program is executed by a computer, the program is stored in a hard disk device or the like in the computer, and is loaded into a main memory and executed.

FIG. 3 is a diagram showing a basic content acquisition method in the embodiment. FIG. 2 is a configuration diagram of a data transfer function according to the embodiment of the present invention. It is a figure showing a network model of this system. FIG. 4 is a diagram showing a data flow between a client and a server. It is a figure showing the contents of response data. FIG. 8 is a diagram illustrating an example of response data to a request for streaming content. FIG. 4 is a diagram illustrating an example of a control file of a local computer. It is a figure showing a control file on the server computer side. It is the first half of the flowchart showing the processing procedure of the local proxy server. It is the latter half of the flowchart showing the processing procedure of the local proxy server. It is a figure showing an example of a synchronous file. It is a figure explaining a shift of a synchronous time axis. FIG. 2 is a configuration diagram of a streaming content synchronization function according to the first embodiment of the present invention. FIG. 9 is a configuration diagram of a second embodiment of the present invention. FIG. 6 is a diagram illustrating an example of source control information. FIG. 16 is a diagram illustrating a performance result based on the source control information of FIG. 15.

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 1 Local computer 1a Information browsing means 1b Duplication information storage means 1ba Local control file 1bb Duplication information 1c Request relay means 2 Server computer 2a Server 2b Distribution information storage means 2ba Server side control file 2bb Distribution information

Claims (10)

In an information management system that manages information distributed from a server computer to a local computer via a network,
The server computer,
Distribution information storing means for storing distribution information to be distributed via the network, and a server-side control file in which attribute information of the distribution information is registered;
The information stored in the distribution information storage unit is distributed in response to a request, and when a request to acquire streaming content whose content changes according to time is received, information to be synchronized with the streaming content is defined. A server that transmits, together with the streaming content, a synchronization file and a synchronization reference time serving as a reference for displaying information defined in the synchronization file,
With
The local computer,
Copy information of the delivery information in the delivery information storage means, and copy information storage means for storing a local control file in which attribute information of the copy information is registered;
Upon receiving the distribution information acquisition request stored in the distribution information storage unit, the server-side control file and the local-side control file are acquired and correspond to the requested distribution information attribute information and the distribution information. Request relay means for comparing the attribute information of the copy information to determine the information to be obtained based on the comparison result,
The streaming content acquisition request is output, and the streaming content returned in response to the request is reproduced, and the acquisition request for the information defined in the synchronization file based on the synchronization reference time sent from the server is issued. Streaming content reproducing means for outputting in synchronization with the streaming content;
Comprising,
An information management system, characterized in that: In an information management system that manages information distributed from a server computer to a local computer via a network,
The server computer,
Distribution information storing means for storing distribution information to be distributed via the network, and a server-side control file in which attribute information of the distribution information is registered;
When distributing the information stored in the distribution information storage means in response to a request, and providing streaming content whose content changes according to time, the streaming information is divided into unit information. A server for adding and transmitting a specification of related information to be synchronized with the content,
With
The local computer,
Copy information of the delivery information in the delivery information storage means, and copy information storage means for storing a local control file in which attribute information of the copy information is registered;
Upon receiving the distribution information acquisition request stored in the distribution information storage unit, the server-side control file and the local-side control file are acquired and correspond to the requested distribution information attribute information and the distribution information. Request relay means for comparing the attribute information of the copy information to determine the information to be obtained based on the comparison result,
The streaming content acquisition request is output, and the unit information of the streaming content returned in response to the request is reproduced, and when the specification of the related information is added to the unit information, the designated Streaming content playback means for outputting the related information acquisition request;
Comprising,
An information management system, characterized in that: In an information management system that manages information distributed and divided into unit information via a network,
When the streaming content acquisition request is received after the start of the provision of the streaming content whose content changes according to the time, a synchronization file in which information to be synchronized with the streaming content is defined, and a synchronization file defined in the synchronization file is defined. A synchronization reference time serving as a reference for displaying information, and a server computer including a streaming server that transmits the streaming content together with the streaming content;
The request for the streaming content is output, and the streaming content returned in response to the request is played back, and a request for acquiring information defined in the synchronization file based on the synchronization reference time sent from the streaming server is transmitted. A local computer comprising streaming content playback means for outputting in synchronization with the streaming content,
An information management system comprising: In an information management system that manages information distributed and divided into unit information via a network,
When providing streaming content whose content changes in accordance with time, a streaming server is provided which adds, to unit information obtained by dividing the streaming content, designation of related information to be synchronized with the streaming content and transmits the unit information. Server computer,
Outputs the request for the streaming content, and reproduces the unit information of the streaming content returned in response to the request, and when the specification of the related information is added to the unit information, the specified A local computer comprising streaming content playback means for outputting a request for obtaining related information,
An information management system comprising: In a server computer that divides streaming content whose content changes according to time into unit information and distributes it,
When the streaming content acquisition request is received after the start of providing the streaming content, a synchronization file in which information to be synchronized with the streaming content is defined, and a reference for displaying information defined in the synchronization file. A streaming reference providing means for transmitting the synchronization reference time together with the streaming content,
A server computer comprising: In a server computer that divides streaming content whose content changes according to time into unit information and distributes it,
When providing the streaming content, a streaming content providing means for transmitting the unit information obtained by dividing the streaming content by adding designation of related information to be synchronized with the streaming content,
A server computer comprising: In a server computer that divides streaming content whose content changes according to time into unit information and distributes it,
A plurality of content storage means for individually storing a plurality of streaming contents sequentially transmitted;
Synthesizing and distributing means for synchronizing the unit information of the plurality of streaming contents from the plurality of content storage means, synthesizing and distributing the extracted plurality of unit information,
A server computer comprising: In a computer-readable recording medium recording a server program for distributing streaming content whose content changes according to time and dividing it into unit information,
When the streaming content acquisition request is received after the start of providing the streaming content, a synchronization file in which information to be synchronized with the streaming content is defined, and a reference for displaying information defined in the synchronization file. And a synchronization reference time, streaming content providing means for transmitting prior to the provision of the streaming content,
A computer-readable storage medium storing a server program, which causes a computer to function as a computer. In a computer-readable recording medium recording a server program for distributing streaming content whose content changes according to time and dividing it into unit information,
When providing the streaming content, a streaming content providing means for transmitting the unit information obtained by dividing the streaming content by adding designation of related information to be synchronized with the streaming content,
A computer-readable storage medium storing a server program, which causes a computer to function as a computer. In a computer-readable recording medium recording a server program for distributing streaming content whose content changes according to time and dividing it into unit information,
A plurality of content storage means for individually storing a plurality of streaming contents sequentially transmitted,
Synthesizing and distributing means for synchronizing the unit information of the plurality of streaming contents from the plurality of content storage means and synthesizing and distributing the extracted plurality of unit information;
A computer-readable storage medium storing a server program, which causes a computer to function as a computer.

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