JPH118654A - Network system and data repeater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To start reproduction of voice data immediately without awaiting the end of down-loading all voice data in the case that a client terminal reproduces the voice data stored in a data storage server without re-processing the data storage server and data stored in the data storage server. SOLUTION: In the case that data received by the data repeater 3 interposed between a data storage server 1 and a client terminal 4 from the data storage server 1 voice data or a request received from the client terminal 4 is sequential reproduction of the voice data, the voice data received from the data storage server 1 are assembled into packets by a size equivalent to the quantity of the voice data reproduced for a prescribed time at each prescribed time interval and then the packet is sent to the client terminal 4. Thus, the client terminal 4 sequentially reproduces voice data included in the packet received from the data repeater 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a data storage server for storing data, a client terminal for presenting data stored in the data storage server, and transmission and reception between the data storage server and the client terminal. In a network system in which a data relay device for relaying data is connected via a network, if the data received from the data storage server is sound data, the data relay device transmits the sound data to a client terminal. The present invention relates to a technique for converting the sound data into a format that allows the reproduction of the sound data to be started before all the sound data is received.

[0002]

2. Description of the Related Art In a conventional network system having a data relay device, a sequence of presenting (displaying / reproducing) data stored in a data storage server at a client terminal is generally as shown in FIG. Become.

As shown in FIG. 31, when a user instructs a client terminal to display / reproduce data stored in a data storage server, first, a browser program communicates with a data relay program of a data relay device. Is connected (S40), and a data request is transmitted (S41).

In the data relay device, the data relay program, upon receiving a data request from the browser program, issues a data request to the proxy server program (S42). Upon receiving the data request from the data relay program, the proxy server program connects a communication line with the stored data transmission program of the data storage server (S43), and transmits the data request (S44).

In the data storage server, upon receiving a data request from the proxy server program, the stored data transmission program checks whether data transmission is possible, and returns a data request response indicating the result to the proxy server program (S45).

Here, if the data transmission is "OK", the stored data transmission program continues to transmit the requested data (S50).

In the data relay device, when the proxy server program receives the data request response from the stored data transmission program, the proxy server program issues a data request response to the data relay program (S46). When the data request response is received from the server, the data request response is transmitted to the browser program (S47).

On the other hand, in the data relay device, when the proxy server program receives all data from the stored data transmission program, the proxy server program transfers the received data to the data relay program (S52), and communicates with the stored data transmission program. Is cut (S51). The data relay program transmits the data passed from the proxy server program to the browser program (S290), and when transmission of all data is completed, disconnects the communication line with the browser program (S295).

In the above-described sequence, especially when sound data is handled, sound data is reproduced at the client terminal after the data transmission in S290 is completed and all sound data arrives at the client terminal. .

[0010] Further, by providing a new dedicated server or storing the sound data previously converted into a unique format in the data storage server, the client terminal can download all the sound data. A system in which reproduction can be started without the need is introduced on pages 202 to 209 of "Internet Magazine January 1996 (issued by SoftBank Corp.)".

[0011]

As described above, in the conventional network system, when sound data stored in the data storage server is to be reproduced on the client terminal, all sound data are downloaded to the client terminal. Otherwise, the reproduction of the sound data could not be started.

[0012] In addition, in the technique introduced in the above-mentioned document, sequential reproduction is realized so that reproduction can be performed before all the sound data has been downloaded. It is necessary to convert the stored sound data into a unique format in advance.

Therefore, an object of the present invention is to provide a data storage server and a method for reproducing a sound data stored in a data storage server without changing a data stored in the data storage server. Another object of the present invention is to realize a sequential reproduction in which reproduction of sound data can be started immediately without waiting for all sound data to be downloaded.

[0014]

According to a first aspect of the present invention, there is provided a data storage server storing at least sound data, and a data storage server storing the sound data. And a data relay device that relays data transmitted and received between the data storage server and the client terminal is a network system connected via a network, wherein the data relay device is If the data received from the data storage server is sound data,
The sound data is packetized in a size corresponding to the data amount of the sound data that can be reproduced in the certain time at regular time intervals, and thereafter, the data relay means for transmitting the packet to the client terminal is provided. There is provided a network system comprising sound data reproducing means for sequentially reproducing sound data included in a packet received from the data relay device.

According to a second aspect of the present invention, there is provided a data storage server storing at least sound data, and a client presenting data stored in the data storage server. A network system in which a terminal and a data relay device that relays data transmitted and received between the data storage server and the client terminal are connected via a network, wherein the data relay device includes the client terminal If the request received from is a sequential reproduction of sound data, the sound data received from the data storage server is transmitted at a predetermined time interval in a size corresponding to the data amount of the sound data that can be reproduced in the predetermined time. Data relay means for packetizing and transmitting the packetized data to the client terminal; It provides a network system, comprising the sound data reproducing means for sequentially reproducing the sound data included in the received packet from the data relaying device.

According to a third aspect of the present invention, there is provided a data storage server storing at least sound data, and a client presenting the data stored in the data storage server. A data relay device connected to a terminal via a network and relaying data transmitted and received between the data storage server and the client terminal, wherein data received from the data storage server is sound data. Data relay means for packetizing the sound data in a size corresponding to the data amount of the sound data that can be reproduced in the fixed time at regular time intervals and transmitting the packet to the client terminal. A data relay device characterized by the above feature is provided.

According to a fourth aspect of the present invention, there is provided a data storage server storing at least sound data, and a client presenting data stored in the data storage server. A data relay device connected to a terminal via a network and relaying data transmitted and received between the data storage server and the client terminal, wherein the request received from the client terminal is a serial data of sound data. In the case of reproduction, the sound data received from the data storage server is packetized at a fixed time interval into a size corresponding to the data amount of sound data that can be reproduced in the fixed time, and then transmitted to the client terminal. There is provided a data relay device comprising a data relay unit for transmitting.

[0018] In the fourth aspect, the data relay means may be arranged so that the data received from the data storage server includes display data for inputting a request for sound data by the user of the client. The data can be transmitted to the client terminal after adding display data for a user of the client to input a request for sequential reproduction.

In any of the third and fourth aspects, the data relay means may reduce the data amount of the sound data received from the data storage server before packetizing the sound data. it can.

Further, in the above client terminal,
The sound data reproducing means may discard packets received in an order later than the order in which they should be received, or if a packet in the order to be received cannot be received, the time when the next packet was received is If the time corresponding to the time interval for packetizing the sound data by the data relay means has elapsed from the time at which the reproduction of the sound data included in the previously received packet was started, this corresponds to one packet. You can play back silence data of data amount,
If the unreproduced sound data exceeds a predetermined amount, newly received packets can be discarded.

Here, the specified amount of unreproduced sound data used by the sound data reproducing means to determine whether or not to discard a packet is determined by a network connected between the data relay device and the client terminal. The sound data reproducing means reproduces a time obtained by adding a transmission delay dispersion absorption time for correcting the dispersion of the transmission delay generated above and a time corresponding to a time interval at which the data relay means packetizes the sound data. The data amount may be equal to or less than the data amount of the possible sound data, and the sound data reproducing means may calculate the transmission delay dispersion absorption time based on a packet reception interval.

[0022]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a configuration diagram of a network system according to an embodiment of the present invention.

As shown in FIG. 1, the network system according to the present embodiment includes a data storage server 1 storing various data, a client terminal 4 for presenting (displaying / reproducing) data, a data storage A data relay device 3 that relays data and commands transmitted and received between the server 1 and the client terminal 4 is connected via a network 2.

The network 2 used here
Is an Ethernet or FDDI (Fi
LAN (Local such as ber Distributed Data Interface)
Area Network (ISDN)
rvices Digital Network) and ATM (Asynchronous Tra)
nsfer Mode).

FIG. 2 is a hardware configuration diagram of the data storage server 1 and the data relay device 3.

As shown in FIG. 2, the data storage server 1 and the data relay device 3 each include a mouse 10, a keyboard 11, a display 12, and a storage device 15 storing various programs and various data. A memory 14 loaded with a program at the time of execution, a CPU (Central Processing Unit) 13 for executing the program, and a communication control unit 17 connected to the network 2 are connected via an internal bus 16. I have.

FIG. 3 is a hardware configuration diagram of the client terminal 4.

As shown in FIG. 3, the client terminal 4
Is a mouse 2 that serves as an input means for commands and the like from the user.
0, a keyboard 21, a display 22 for displaying contents indicating the execution state of the program, etc., a storage device 25 for storing various programs, a memory 24 for loading the programs when they are executed, and executing the programs. The configuration is such that an audio decoding device 28 to which a CPU 23, an audio output device 29 (for example, a speaker) is connected, and a communication control unit 27 connected to the network 2 are connected via an internal bus 26.

It should be noted that instead of the audio decoding device 28, C
A speech decoding program executed by the PU 23 may be used.

As a means for inputting commands and the like from the user, a tablet, a pen input device, or the like may be used instead of the mouse 20 or the keyboard 21.

FIG. 4 is an explanatory diagram showing an outline of the operation of a program executed by the CPU 13 of the data storage server 1.

As shown in FIG. 4, in the data storage server 1, when the stored data transmission program 30 receives the data request transmitted from the data relay device 3 via the communication control unit 17, the stored data transmission program 30 stores the data request in the storage device 15. The operation of transmitting the requested data among the data being transmitted to the data relay device 3 via the communication control unit 17 is performed.

The stored data transmission program 30
Conventionally, it is the same as that used in the data storage server.

FIG. 5 is an explanatory diagram showing an outline of the operation of a program executed by the CPU 13 of the data relay server 3.

As shown in FIG. 5A, in the data relay device 3, when the data relay program 32 receives a command transmitted from the client terminal 4 via the communication control unit 17, it analyzes the command. Then, it operates to pass the command to the proxy server program 31. The proxy server program 31 operates to transmit the command passed from the data relay program 32 to the data storage server 1 via the communication control unit 17.

On the other hand, as shown in FIG. 5B, in the data relay device 3, the proxy server program 31 transmits the data transmitted from the data storage server 1 to the communication control unit 17.
When receiving the data via the data relay program 32, the data relay program 32 operates. Data relay program 32
Represents the data passed from the proxy server program 31,
Based on the result of the analysis of the command performed earlier, after performing processing such as reduction of the data amount as required, the operation is performed so as to be transmitted to the client terminal 4 via the communication control unit 17.

In the present embodiment, especially when the target data is sound data, the data relay program 32 divides the sound data into equal packets as described later in detail, and transmits the packets at regular time intervals. The sound data relay process is performed.

Conventionally, the proxy server program 31 is used alone in the data relay device, and relays a command transmission from the client terminal 4 to the data storage server 1 and a data transmission from the data storage server 1 to the client terminal 4. This is the same as what was working as

In the present embodiment, the data relay device 3 has a data relay program 32 interposed between the client terminal 4 and the proxy server program 31 to reduce the amount of data during data relay, etc.
A feature is that sound data relay processing is performed when the target data is sound data.

It is to be noted that reduction of the data amount performed at the time of data relay can be realized by thinning out sound data.

FIG. 6 is an explanatory diagram showing an outline of the operation of a program executed by the CPU 23 of the client terminal 4.

As shown in FIG. 6, in the client terminal 4, when the browser program 33 receives a command such as a data request input from the user via the mouse 20 or the keyboard 21, the browser program 33 transmits the command to the communication control unit 2.
7 to transmit the data to the data relay device 3 via the communication device 7.

In this embodiment, when the requested data is sound data, the user can instruct a sequential reproduction request as a reproduction method.

Therefore, the browser program 33 operates to activate the sound data receiving / reproducing program 34 when the user instructs the sequential reproduction request, and the sound data receiving / reproducing program 34 When the sound data transmitted from the communication device is received via the communication control unit 27, the sound data is reproduced via the sound decoding device.

FIG. 8 is an explanatory diagram showing an example of the display contents of the hypertext by the browser program 33.

In the client terminal 4, the browser program 33 displays the hypertext transmitted from the data relay device 3 on the display 22.

In FIG. 8, an anchor tag 37 for realizing a hyperlink to sound data is displayed on the display 22, as in the conventional hypertext display method.

Further, in this embodiment, the display 2
In FIG. 2, a sequential playback button 38 for the user to instruct a sequential playback request is displayed.

In this embodiment, the sequential playback button 3
8 is provided by the data relay device 3, and the data relay device 3
(2) analyzing the hypertext passed from the proxy server program 31 (the hypertext transmitted from the data storage server 1) and embedding information indicating the location (address) of the sound data in the hypertext; , After adding the sequential playback button 38,
The hypertext is transmitted to the client terminal 4.

When the user selects (clicks) the anchor tag 37, the client terminal 4 transmits all sound data to the client terminal 4 in the same manner as in the prior art.
When the user clicks the sequential playback button 38, the operation is started.
It operates to perform sequential reproduction.

Here, in the former case, that is, when the data requested by the data request transmitted from the browser program 33 is sound data, the data relay device 3 transmits the sound data transmitted from the data storage server 1. In the latter case, that is, when the data requested by the data request transmitted from the browser program 33 is sound data and the sequential playback button 38 is clicked, ,
It operates to perform sound data relay processing on the sound data transmitted from the data storage server 1.

Note that, without displaying the sequential playback button 38, for example, as shown in FIG. 7, an anchor tag 36 for realizing a hyperlink to sound data is displayed in the same manner as in the conventional hypertext display method. Only when the user clicks the anchor tag 36,
The operation may always be performed so as to perform the sequential reproduction.

Here, when the data requested by the data request transmitted from the browser program 33 is sound data, the data relay device 3 always relays the sound data transmitted from the data storage server 1 for the sound data. Operate to perform processing.

Hereinafter, a process for reproducing the sound data stored in the data storage server 1 by the client terminal 4 will be described. Here, the difference from the prior art, that is, the data which is a feature of the present embodiment, will be described. A description will be given of a process for realizing sequential reproduction of sound data by performing a relay process.

FIG. 9 is a sequence diagram showing the flow of processing when sound data stored in the data storage server 1 is sequentially reproduced by the client terminal 4.

As shown in FIG. 9, when the user instructs the client terminal 4 to request the sequential reproduction of the sound data stored in the data storage server 1, for example, the anchor tag shown in FIG. When the user clicks the button 36 or clicks the sequential playback button 38 shown in FIG.
Connects a communication line with the data relay program 32 (S40) and transmits a data request (S41).

In the data relay device 3, when receiving the data request from the browser program 33, the data relay program 32 issues a data request to the proxy server program 31 (S42). Proxy server program 31
Receives the data request from the data relay program 32, connects the communication line with the stored data transmission program 30 (S43), and transmits the data request (S4).
4).

In the data storage server 1, upon receiving a data request from the proxy server program 31, the stored data transmission program 30 checks whether data transmission is possible and returns a data request response indicating the result to the proxy server program 31. (S45).

Here, the stored data transmission program 30
Will continue to send data if it is "OK"
The requested sound data is transmitted (S50).

In the data relay device 3, when the proxy server program 31 receives a data request response from the stored data transmission program 30, the proxy server program 31
(S46). Similarly, when the data relay program 32 receives the data request response from the proxy server program 31, the browser program 3
Then, a data request response is transmitted to S3 (S47).

In the client terminal 4, if the result indicated by the data request response received from the data relay program 32 is "OK", the browser program 33 issues an activation request to the sound data reception / reproduction program 34. (S48), the sound data receiving and reproducing program 3
Start 4

Now, in the data relay device 3, the proxy server program 31
When all the sound data is received from the server, the received sound data is transferred to the data relay program 32 (S52), and the communication line with the stored data transmission program 30 is disconnected (S51).

In the data relay device 3, after transmitting a data request response to the browser program 33, the data relay program 32 disconnects the communication line with the browser program 33 (S49), and receives and reproduces sound data. A communication line with the program 34 is connected (S5
3). Then, after the sound data is passed from the proxy server program 31, the data format of the sound data is checked, and the checked data format is notified to the sound data receiving / reproducing program 34 (S54). The reception / playback program 34 checks whether or not the environment is such that the data format notified from the data relay program 32 can be played back, and returns a playback enable / disable notification indicating the check result to the data relay program 32 (S55). .

In the data relay device 3, the data relay program 32 is passed from the proxy server program 31 when the result indicated by the reproduction permission / inhibition notification received from the sound data reception / reproduction program 34 is “permitted”. The sound data relaying process, which is a process of packetizing the sound data into a fixed size (a size corresponding to the amount of data reproducible in the fixed time) at regular time intervals and transmitting the packet to the sound data receiving / reproducing program 34, is performed. When the transmission is completed (S56) and transmission of all sound data is completed, a data transmission completion notification is transmitted to the sound data reception / reproduction program 34 (S57).

In the client terminal 4, the sound data receiving / reproducing program 34 realizes the sequential reproduction by sequentially reproducing the sound data packetized and transmitted at regular time intervals after receiving the packet. When the reproduction of all sound data is completed, the communication line with the data relay program 32 is disconnected (S5).
8).

When the data relay program 32 transmits the sound data to the sound data receiving / reproducing program 34 (S56), the time interval for packetizing the sound data should be, for example, a value of 40 msec. Can be. Then, the data relay program 32 includes sound data of a data amount that can be reproduced in the time set here (for example, 40 msec).

It should be noted that, as the value of the time interval set here becomes larger, the influence of the packet loss becomes larger, so the upper limit value is desirably less than 1 second.
On the other hand, it is desirable that the lower limit value be several tens msec or more in order to suppress the load of the transmission processing.

In the above example, the transfer of the sound data from the proxy server program 31 to the data relay program 32 (S 52) is performed after the proxy server program 31 has received all the sound data from the stored data transmission program 30. , But proxy server program 3
1 may start passing the sound data received from the stored data transmission program 30 to the data relay program 32 one after another from the received sound data.

Along with this, the notification of the data format (S54) and the data transmission (S56) in the data relay program 32 are also required at the stage of receiving the information of the header describing the data format and for packetization. The processing may be started from a stage where sound data of a data amount corresponding to time is received.

FIG. 10 is a flowchart showing a processing procedure of the browser program 33 when the sound data stored in the data storage server 1 is sequentially reproduced by the client terminal 4.

As shown in FIG. 10, the client terminal 4
In the case where the user has instructed a request for sequential reproduction of the sound data stored in the data storage server 1, ie, for example, the user clicked on the anchor tag 36 shown in FIG. When the user clicks the sequential playback button 38 (step 60), the browser program 33 connects a communication line with the data relay program 32 (step 61) and transmits a data request command (step 62). .

When the data request response is returned from the data relay program 32 (step 63), the browser program 33 checks the result indicated by the data request response (step 64). If not "error", the sound data receiving / reproducing program 34
Is started (step 65).

When the result indicated by the data request response is “No” or “Error”, and when the sound data receiving / reproducing program 34 has been started, the browser program 33 executes the data relay program. Then, the communication line to the H.32 is disconnected (step 66).

On the other hand, when the user instructs a request other than the sequential reproduction of the sound data stored in the data storage server 1 (step 6).
0), if the request is a request to end the browser program 33, the process is terminated (step 67); if the request is any other request (eg, a request to display another page)
Other processing according to the request is performed (step 68).

FIG. 11 is a flowchart showing the processing procedure of the data relay program 32 when the client terminal 4 sequentially reproduces the sound data stored in the data storage server 1.

As shown in FIG. 11, in the data relay device 3, upon receiving the data request command from the browser program 33 (step 70), the data relay program 32 issues a data request command to the proxy server program 31 (step 70). 71).

Thereafter, when receiving the data request response from the proxy server program 31 (step 72), the data relay program 32 transfers the data request response to the browser program 33 (step 73).

Here, if the content of the received data request response is "OK" (step 74), the data relay program 32
4 is performed (step 75), and if the content of the received data request response is "NO" or "ERROR" (step 74), nothing is performed.

FIG. 12 is a flowchart showing a detailed processing procedure of the communication processing performed in step 75 of FIG.

As shown in FIG. 12, step 7 in FIG.
In the communication process of No. 5, the data relay program 32
First, a communication line is connected to the sound data receiving / reproducing program 34 (step 80). When there is no notification of a data reception error from the proxy server program 31 (step 81) and the requested sound data is received safely (step 82), the necessity of compression or data format conversion is checked (step 96).

[0099] As a material for this determination, for example, the setting of the data relay device 3 and the band of the network 2 between the data relay device 3 and the client terminal 4 are exemplified.

In the former case, if the format of the sound data transmitted from the data relay device 3 is fixed, when data in any other format is received, compression or data format conversion is performed. For example, the data relay device 3
GSM (Global Sys.)
tem for Mobile telecommunication), MPEG1 (Moving Picture Experts Group 1) /
When audio data compressed in the audio format is received, conversion of the compression format is performed.

In the latter case, for example, the network 2 between the data relay device 3 and the client terminal 4
If the connection is a dial-up connection of 22.8 kbps by a modem, the data format is changed so that the bit rate of the sound data transmitted from the data relay device 3 is also 22.8 kbps or less.

When the data relay program 32 determines that compression or data format conversion is necessary (step 96), it sets "1" in the conversion flag (step 97). "0" in the conversion flag
Is set (step 98).

Subsequently, the data relay program 32 checks the data format such as compression or non-compression status, sample size, sampling frequency, monaural or stereo status, and notifies the data format to the sound data receiving / reproducing program. (Step 83). If “1” is set in the conversion flag, the converted data format is notified.

Thereafter, when the data relay program 32 receives the reproduction permission / inhibition notification from the sound data reception / reproduction program 34, if the content of the reproduction permission / inhibition notification is “reproducible” (step 84), the data conversion program 32 performs data conversion. (Compression) processing is performed (step 85), and sound data relay processing is performed (step 86). When the transmission of all sound data is completed, a data transmission completion notification is transmitted to the sound data reception / reproduction program 34 (step 88), and the communication line with the sound data reception / reproduction program 34 is disconnected (step 88). 89).

On the other hand, when a data reception error is notified from the proxy server program 31 (step 81), the data relay program 32 notifies the sound data reception / reproduction program 34 of an error (step 87).
The communication line with the sound data receiving / reproducing program 34 is disconnected (step 89).

In the flowchart shown in FIG. 12, the data conversion (compression) processing in step 85 and the processing in steps 96 to 98 are performed when the data relay apparatus 3 does not convert the data format, Network 2 between device 3 and client terminal 4
This is unnecessary when the band of the above can be sufficiently secured, and can be omitted.

FIG. 13 is a flowchart showing a detailed processing procedure of the data conversion (compression) processing performed in step 85 of FIG.

As shown in FIG. 13, step 8 in FIG.
In the data conversion (compression) processing of No. 5, the data relay program 32 checks the conversion flag (step 92).
If "1" is set, the data format is converted (step 94), and if "0" is set, nothing is done.

FIG. 14 is a flowchart showing a detailed processing procedure of the sound data relay processing performed in step 86 of FIG.

As shown in FIG. 14, step 8 in FIG.
In the sound data relay processing of No. 6, the data relay program 32 firstly sets the packetization time (Tp) and the data amount of sound / sound data (Lp) included in one packet.
Is set (step 100), and the transmission sequence number assigned to each packet is initialized (step 10).
1) A timer value is set as a timer reference value (Ts) (step 102).

Here, the packetization time (Tp) is
For example, a value such as 40 msec can be set. The size of the data amount (Lp) is the packetization time.
The size is set to be equal to or larger than the data amount of the sound data reproduced at the same time as (Tp).

Note that the processing in steps 100 to 102 may be executed in a different order.

Subsequently, the data relay program 32 compares the value obtained by subtracting the timer reference value (Ts) from the current value (Tn) of the timer with the packetization time (Tp) (step 10).
4) When the value obtained by subtracting Ts from Tn becomes larger than Tp, 1 Lp of sound data of untransmitted sound data among sound data received from the proxy server program 31 is packetized, and sound data reception / Reproduction program 3
4 (step 105).

After transmitting the packet, the data relay program 32 checks the amount of remaining data (step 106). If any untransmitted sound data remains, the data relay program 32 updates the transmission sequence number (step 107) and sets a timer. Reference value
After (Ts) is reset (step 108), the process returns to step 104. Then, Step 104 to Step 10
When the transmission of all the sound data is completed after repeating the processing of step 8 (step 106), the sound data relay processing ends.

The transmission of the sound data from the data relay program 32 to the sound data receiving / reproducing program 34 is performed before the transfer of the sound data from the proxy server program 31 to the data relay program 32 (S52 in FIG. 9) is completed. , The communication process performed in step 75 of FIG. 11 is as described below.

FIG. 15 is a flowchart showing another detailed processing procedure of the communication processing performed in step 75 of FIG.

In FIG. 15, steps 80, 81, 83 to 85 and 87 to 89 are the same as those in FIG.

As shown in FIG. 15, in step 282, unlike step 82, the data relay program 32
Even if the reception of all the sound data is not completed, when the head data (first data) including the information on the data format is received (step 282), the process proceeds to step 83, where the sound data reception / The data format is notified to the reproduction program 34.

When the data relay program 32 receives the reproduction permission / inhibition notification from the sound data reception / reproduction program 34, if the content of the reproduction permission / non-permission notification is "reproduction possible" (step 84), the proxy server After receiving a part of the remaining sound data from the program 31 (step 2
84) Then, the process proceeds to a step 85, wherein a data conversion (compression) process is performed on the newly received sound data. And
When step 85 is completed, a sound data relay process, which will be described in detail with reference to FIG. 16, is performed (step 286). When transmission of all the sound data is completed (step 288), the processes after step 88 are performed.

On the other hand, if there is untransmitted sound data, the data relay program 32 returns to step 284 to continue the processing.

FIG. 16 is a flowchart showing the detailed processing procedure of the sound data relay processing performed in step 286 of FIG.

In FIG. 16, steps 100 to 105, step 107 and step 108 are the same as those in FIG.
Is the same as

As shown in FIG. 16, the data relay program 32 first checks whether or not it is the first packet transmission (step 109). And Step 100 ~
The process of step 102 is performed only at the time of the first packet transmission, and only the process of step 104 and thereafter is performed for the second and subsequent times.

The difference from the processing shown in the flowchart of FIG. 14 is that step 106 is eliminated and step 1
In 04, when the value obtained by subtracting Ts from Tn is smaller than Tp, and when step 108 is completed, the sound data relay processing is terminated.

FIG. 17 is a flowchart showing the processing procedure of the proxy server program 31 when the client terminal 4 sequentially reproduces the sound data stored in the data storage server 1.

As shown in FIG. 17, in the data relay device 3, when the proxy server program 31 receives a data request command from the data relay program 32 (step 110), it establishes a communication line with the stored data transmission program 30. Connection is made (step 111), and a data request command is transferred to the stored data transmission program 30 (step 112).

Thereafter, when the proxy server program 31 receives a data request response from the stored data transmission program 30 (step 113), it notifies the data relay program 32 of the contents of the data request response (step 11).
4). Here, if the content of the data request response is "OK", that is, if it indicates that data transmission is possible (step 115), the sound continuously transmitted from the stored data transmission program 30 Receive data.

Then, the proxy server program 31 finishes receiving all sound data normally (step 11).
6), the received sound data is transferred to the data relay program 32 (step 117), and the communication line with the stored data transmission program 30 is disconnected (step 11).
8).

On the other hand, if the content of the data request response is “NO” or “ERROR” (step 115), the proxy server program 31
Is disconnected (step 118).

If all the sound data cannot be received normally (step 116), the proxy server program 31 notifies the data relay program 32 of an error (step 119), and then the stored data transmission program 30 Is disconnected (step 118).

FIG. 18 is a flowchart showing the processing procedure of the stored data transmission program 30 when the client terminal 4 sequentially reproduces the sound data stored in the data storage server 1.

As shown in FIG. 18, the data storage server 1
When the stored data transmission program 30 receives the data request command from the proxy server program 31 (step 120), the stored data transmission program 30 checks whether or not the requested sound data can be transmitted, and transmits a data request response indicating the check result to the proxy server program 31. 31 is returned (step 122). If the data transmission is "OK" (step 12)
4), the requested sound data is transferred to the proxy server program 31
(Step 126).

FIG. 19 is a flowchart showing the processing procedure of the sound data receiving / reproducing program 34 when the client terminal 4 successively reproduces the sound data stored in the data storage server 1.

As shown in FIG. 19, the client terminal 4
When the sound data receiving / reproducing program 34 receives the data format notification of the sound data to be transmitted from the data relay program 32 (step 130), it determines whether or not the data format can be reproduced. (Step 131) If it is determined that reproduction is possible, the data relay program 32 is notified that "reproduction is possible" (Step 132). Until a data transmission completion notification is transmitted from the data relay program 32 (step 134), the reception and reproduction processing of the packet transmitted from the data relay program 32 is performed (step 135).

On the other hand, the sound data receiving / reproducing program 34
Determines that reproduction of the data format notified by the data format notification is impossible (step 13
1), the data relay program 32 is notified that the reproduction is not possible (step 133).

FIG. 20 is a flowchart showing a detailed processing procedure of the packet reception / reproduction processing performed in step 135 of FIG.

As shown in FIG. 20, step 1 in FIG.
In the packet receiving / reproducing process 35, the sound data receiving / reproducing program 34 first sets the current time as a variable (Tn).
(Step 140).

Subsequently, the sound data receiving / reproducing program 3
4 confirms whether or not the first packet of the packet transmitted from the data relay program 32 has already been received (step 141), and if not, performs the processing of step 146 and subsequent steps. If received, the state of the reproduction start flag and the current time (Tn)
The relationship between the time and the reproduction start time is checked (step 142).
If the reproduction start flag is “OFF” and the current time (Tn) is greater than the reproduction start time, the reproduction start flag is changed to the “ON” state, and the audio decoding device 28 starts reproduction. (Step 143).

Subsequently, the sound data receiving / reproducing program 3
4 receives the packet transmitted from the data relay program 32 (step 146). If the received packet is the first packet (step 14)
7), playback start time, next packet playback start limit time (T
e), setting a reception sequence number (step 14)
8).

Specifically, in step 148, the sound data receiving / reproducing program 34 sets the reproduction start time to a value obtained by adding the transmission delay dispersion absorption time (Td) to the current time (Tn), The limit time (Te) is a value obtained by adding the packetization time (Tp) to the reproduction start time.

Note that the value of the transmission delay dispersion absorption time (Td) is set by the transmission delay dispersion observation process described later, but since it is closely related to the reproduction start time, its initial value is too large. Is not desirable. In practice, it is desirable to set a value between a value around the packetization time (Tp) and less than 1 second.

On the other hand, the sound data receiving / reproducing program 34
When the received packet is not the first packet (step 147), the transmission delay dispersion observation process described in detail with reference to FIG. 21 is performed (step 149).

Subsequently, the sound data receiving / reproducing program 3
No. 4 compares the sequence number assigned to the received packet with the stored received sequence number to check whether or not there is any packet loss (step 150). If a packet loss is detected, the current time (Tn) is compared with the reproduction start limit time (Te) (step 151).
If n is smaller than Te, silent data corresponding to the time obtained by subtracting Tn from Te is output to the audio decoding device 28.
(Step 152).

Subsequently, the sound data receiving / reproducing program 3
No. 4 resets the reproduction start limit time (Te) and updates the reception sequence number (step 153).

More specifically, the sound data reception / reproduction program 34 determines in step 153 that the reproduction start limit time (T
e) is a value obtained by adding the packetization time (Tp) to the reproduction start limit time (Te) before updating.

The sound data receiving / reproducing program 34
Indicates that no packet loss is detected (step 1
50) and when the processing of step 153 is completed,
Again, the sequence number assigned to the received packet is compared with the stored received sequence number to check whether or not the sound data contained in the packet should be reproduced (step 154).

For example, if the sequence number given to the received packet is smaller than the number expected to be received, the packet is a packet that arrived with a delay and has already been received by the next packet. In such a case, the sound data receiving / reproducing program 34 does not reproduce the sound data included in the packet, and it means that the reproduction has been completed. Is repeated.

Then, the sound data receiving / reproducing program 3
4 judges that the audio data should be reproduced (step 154), checks the data amount of the sound data remaining in the audio decoding device 28 (step 155), and checks the data amount to be transmitted. If it is larger than the amount of sound data corresponding to the delay dispersion absorption time (Td) plus 1 Lp, the reception sequence number is updated (step 15).
7) Return to step 146 again. If the examined sound data amount is equal to or less than the data amount of sound data corresponding to the transmission delay dispersion absorption time (Td) plus 1 Lp, the sound data included in the received packet is converted to the sound data. The data is written to the decoding device 28 and the reproduction start time limit (Te)
Is reset (step 156), the reception sequence number is updated (step 157), and step 14 is performed again.
Return to 6.

More specifically, the sound data receiving / reproducing program 34 determines in step 156 that the reproduction start limit time (T
e) at the time when the sound data contained in the received packet is written into the audio decoding device 28,
p) is added.

In the flow chart shown in FIG. 20, when a speech decoding program is used instead of the speech decoding device 28, the sound data receiving / reproducing program 34 executes steps 143, 152,
Steps 155 and 156 are performed on the audio decoding program. If the sound data receiving / reproducing program 34 determines that the sound data should be reproduced (step 154), it skips step 155, performs step 156, and then proceeds to step 15
7 may be performed.

FIG. 21 is a flowchart showing a detailed processing procedure of the transmission delay dispersion observation processing performed in step 149 of FIG.

As shown in FIG. 21, step 1 in FIG.
In 49 transmission delay dispersion observation processing,
The reproduction program 34 first obtains observation data of the transmission delay time (step 160). The details of the acquisition method will be described with reference to FIG.

Subsequently, the sound data receiving / reproducing program 3
4 updates the transmission delay observation counter when the transmission delay time observation counter is smaller than “100”, that is, when the number of transmission delay time observation data is less than “100” (step 161) (step 161). 162), the transmission delay dispersion observation processing ends.

A sound data receiving / reproducing program 34
If the transmission delay time observation counter is equal to or greater than "100" (step 161), the transmission delay time observation counter is initialized to "0" (step 163), and based on the stored transmission delay time observation data. Then, a new transmission delay dispersion absorption time (Tdn) is calculated (step 164).

As a calculation method, a method of obtaining a variance distribution of the transmission delay time and obtaining a transmission delay time that includes 95% or more of the received packet can be employed. Also,
In the same calculation, 90% or more of the received packet may be included, or another calculation method may be used. However, if the content of the sound data to be reproduced is something like speech, in order to prevent interruption of the sound due to packet loss from hindering the understanding of the content,
It is desirable that the allowable rate of received packets be 95% or more.

Subsequently, the sound data receiving / reproducing program 3
4 compares the transmission delay dispersion absorption time (Td) with the new transmission delay dispersion absorption time (Tdn) (step 165),
If d is smaller than Tdn, silent data corresponding to the time obtained by subtracting Td from Tdn is output to the audio decoding device 28.
(Step 166), the transmission delay dispersion absorption time
After updating (Td) to the new transmission delay dispersion absorption time (Tdn) (step 169), the transmission delay dispersion observation processing ends.

On the other hand, the sound data receiving / reproducing program 34
Is that Td is not less than Tdn (step 165),
If Td is greater than Tdn (step 167),
Sound data corresponding to the time obtained by subtracting Tdn from Td is
It is deleted from the audio decoding device 28 (step 168), and the transmission delay dispersion absorption time (Td) is replaced with the new transmission dispersion absorption time (Td).
After updating to n) (step 169), the transmission delay dispersion observation processing ends.

Here, instead of deleting the audio data in the audio decoding device 28 in step 168, the audio data corresponding to the difference between Td and Tdn is deleted from the audio data to be written to the audio decoding device 28 next. You can do it.

The sound data receiving / reproducing program 34
If Td is not greater than Tdn (step 167), the transmission delay dispersion absorption time (Td) is updated to the new transmission delay dispersion absorption time (Tdn) (step 16).
9), end the transmission delay dispersion observation processing.

In the flowchart shown in FIG. 21, the transmission / reception program 34 used by the sound data receiving / reproducing program 34 to determine in step 161 whether to update the transmission delay dispersion absorption time (Td). Although it is determined whether or not the delay time observation counter is smaller than “100”, a value other than “100” may be used.

The upper limit value of the transmission delay observation counter is a value for defining at what interval the transmission delay dispersion absorption time (Td) is to be reviewed. 1 in maturation time (Tp) [msec]
A value obtained by dividing 000T [msec] may be set as the Td value.

In order not to delete the sound data as much as possible, the processing of steps 167 and 168 may be omitted. Further, when a voice decoding program is used in place of the voice decoding device 28, the sound data receiving / reproducing program 34 performs the processing of steps 166 and 168 on the voice decoding program.

FIG. 22 is an explanatory diagram showing an example of a method of acquiring transmission delay time observation data in step 160 of FIG.

In FIG. 22, reference numeral 170 denotes a side for transmitting sound data. Here, the data relay program 32 corresponds to this. Reference numeral 171 (black triangle) indicates a transmission timing of a packet including sound data.

As shown at 172, the transmitting side 170 transmits packets including sound data at time intervals of the packetization time (Tp).

In FIG. 22, reference numeral 173 denotes a side for receiving sound data. Here, the sound data receiving / reproducing program 34 corresponds to this.

Since the receiving side 173 does not know when the transmitting side 170 transmitted the packet, the receiving side 173 has the same time interval (packetization time (T
In p)), a reception observation point indicated by 175 (open triangle mark) is provided, and a difference 177 between the reception observation point 175 and the actual reception time 176 is obtained. Since the difference distribution has the property of being equal to the actual transmission delay time distribution,
The receiving side 173 can calculate the transmission delay dispersion absorption time (Td) from the observation data.

FIG. 23 is an explanatory diagram showing an example of a sequence when a packet including sound data is transmitted and received.

In FIG. 23, reference numeral 180 denotes a side for transmitting a packet containing sound data. Here, the data relay program 32 corresponds to this. Reference numeral 181 denotes a side that receives a packet including sound data.
This corresponds to the sound data receiving / reproducing program 34. Reference numeral 182 denotes a network connecting between the transmission side 180 and the reception side 181.

The transmitting side 180 sets the packetization time (Tp) 1
At time intervals of 83, the sound data is packetized, and a sequence number 185 is assigned to each packet 184 and transmitted.

The receiving side 181 receives the first packet 1
After the transmission delay dispersion absorption time (Td) 187 elapses from the reception time of the first packet 186, the sound data included in the sound data 86 is written into the audio decoding device 28, thereby starting reproduction. Thereafter, when the receiving side 181 receives the packet, it sequentially reproduces the sound data contained in the packet by writing the sound data in the sound decoding device 28.

Here, as shown at 188 and 189, even if the packetization time (Tp) has elapsed since the start of the reproduction of the sound data contained in the previously received packet,
If the next packet has not arrived, the receiving side 181
In, as shown at 190, a silent state is maintained until the next packet arrives.

As shown in 191, when a packet is lost during transmission, the receiving side 181
At the stage of receiving the next packet 192, it is considered that a packet loss has occurred, and this reception timing is determined by the packetization time (Tp) since the start of reproduction of the sound data included in the packet 193 received last time. If it is before the lapse, the sound data included in the newly received packet 194 is written into the speech decoding device 28 after the silence data of the lost packet is written to the speech decoding device 28.
Write to 8. Even if you do not write silence data,
Since no sound data is given to the sound decoding device 28, a soundless state results.

On the other hand, if the reception timing is after the elapse of the packetization time (Tp) from the start of the reproduction of the sound data included in the packet 193 previously received, the transmission side 181 immediately , Newly received packet 1
The sound data contained in 94 is written to the audio decoding device 28.

Although not shown, the receiving side 181
May receive packets in a different order than the sending order of the sending side 180.
If you receive a packet that is out of order,
You can see that in the order of the packets received later,
For packets received in an order later than the order in which they should be received, the packets are discarded so that the sound data contained in the packets is not reproduced.

FIG. 24 is an explanatory diagram showing an example of the sequence in the case where the processing of steps 155 and 156 of FIG. 20 has been performed.

In FIG. 24, reference numerals 180 to 183 are the same as those in FIG.

The processing in steps 155 and 156 is performed by the packetization time (Tp) 18 which is counted by each of the transmitters 180 and 181 due to a clock difference or the like.
This is performed in a case where there is a difference between 3,200 and, as a result, sound data is accumulated in the receiving side 181.

At the time 202 when the packet is received, if more than two packets of sound data are stored at the time 202 when the packet is received, the receiving side 181 discards the packet and includes the sound data in the packet. The sound data included in the next received packet 206 is reproduced without reproducing the sound data that is present.

As described above, according to the present embodiment, the data relay device 3 converts the sound data received from the data storage server 1 into sound data that can be reproduced in the fixed time at regular time intervals. Since the data is packetized and transmitted in a size corresponding to the data amount, and the client terminal 4 sequentially reproduces the sound data included in the packet received from the data relay device 3, the data storage server 1 and the Even when the sound data stored in the data storage server is not changed at all, when the client terminal 4 reproduces the sound data stored in the data storage server 1, the client terminal 4 finishes receiving all the sound data to be reproduced. It is possible to immediately start the reproduction of the sound data without waiting.

Finally, specific formats of data and commands transmitted and received between the data storage server 1 and the data relay device 3 and between the data relay device 3 and the client terminal 4 will be described. This will be briefly described with reference to FIG.

FIG. 25 is an explanatory diagram showing the format of a data request command transmitted from the client terminal 4 to the data storage server 1 via the data relay device 3.

In FIG. 25, 210 is a communication header, 2
Reference numeral 12 denotes an identifier indicating a data request, and reference numeral 214 denotes a request content. In the client terminal 4, the browser program 33 sets information such as the file name and location of the data selected in accordance with the instruction from the user in the request 214, and transmits the information to the data relay program 32.

FIG. 26 is an explanatory diagram showing the format of a data request response command transmitted from the data storage server 1 to the client terminal 4 via the data relay device 3.

In FIG. 26, reference numeral 220 denotes a communication header, 2
Reference numeral 22 denotes an identifier indicating a data request response, and reference numeral 224 denotes a result of the data request command. In the data storage server 1, the stored data transmission program 30 sets whether or not the requested sound data can be transmitted in the result 224, and transmits the result to the proxy server program 31.

FIG. 27 is an explanatory diagram showing the format of a data format notification command used when the data relay program 32 notifies the sound data receiving / reproducing program 34 of the data format of sound data.

In FIG. 27, reference numeral 230 denotes a communication header, 2
31 is an identifier indicating that the command is a data format notification command;
232 to 235 are details of the data format, 232 is the coding format, 233 is the number of channels, 234 is the sampling rate, and 235 is the sample size. This data format notification command is transmitted from the data relay program 32 to the sound data receiving / reproducing program 3 in step 83 of FIG.
4 is a command transmitted to the C.4.

FIG. 28 shows a sound data receiving / reproducing program 3
4 is an explanatory diagram showing a format of a reproduction permission / inhibition notification command used when notifying the data relay program 32 of permission / inhibition of sound data reproduction; FIG.

In FIG. 28, reference numeral 230 denotes a communication header, 2
42 is an identifier indicating that the command is a reproduction permission / inhibition notification command;
Reference numeral 44 denotes a result indicating whether or not reproduction is possible. When receiving the data format notification command from the data relay program 32, the sound data receiving / reproducing program 34 includes, in the result 244, a result of determining whether or not the sound data in the data format indicated by the data format notification command can be reproduced. Is set, and a reply is sent to the data relay program 32. The reproduction permission / inhibition notification command corresponds to steps 132 and 133 in FIG.
Is a command transmitted from the sound data reception / reproduction program 34 to the data relay program 32.

FIG. 29 is an explanatory diagram showing the format of a packet used for transmitting sound data from the data relay program 32 to the sound data receiving / reproducing program 34.

In FIG. 29, reference numeral 250 denotes a communication header, 2
52 is an identifier indicating a data packet, 254 is a sequence number, 256 is a data size indicating the data amount of sound data, and 258 is a sound data body. The data relay program 32 packetizes the sound data received from the proxy server program 31 into packets of a format as shown in FIG. 29 by 1 Lp, and transmits the packets to the sound data receiving / reproducing program 34.

FIG. 30 is an explanatory diagram showing the format of a data transmission completion notification command transmitted from the data relay program 32 to the sound data receiving / reproducing program 34.

In FIG. 30, 230 is a communication header, 2
Reference numeral 62 denotes an identifier indicating that the command is a data transmission completion notification command. This data transmission completion notification command is issued when all the sound data has been transmitted from the data relay program 32 to the sound data receiving / reproducing program 34, that is, at step 88 in FIG.
2 to the sound data receiving / reproducing program 34.

[0177]

As described above, according to the present invention, the client terminal is stored in the data storage server without modifying the data storage server and the data stored in the data storage server. When reproducing the sound data, it is possible to realize the sequential reproduction such that the reproduction of the sound data can be started immediately without waiting for all the sound data to be downloaded.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a network system according to an embodiment of the present invention.

FIG. 2 is a hardware configuration diagram of a data storage server and a data relay device.

FIG. 3 is a hardware configuration diagram of a client terminal.

FIG. 4 is an explanatory diagram showing an outline of an operation of a program executed by a CPU of the data storage server.

FIG. 5 is an explanatory diagram showing an outline of an operation of a program executed by a CPU of the data relay device.

FIG. 6 is an explanatory diagram showing an outline of an operation of a program executed by a CPU of a client terminal.

FIG. 7 is an explanatory diagram showing an example of display contents of a hypertext by a browser program.

FIG. 8 is an explanatory diagram showing an example of display contents of a hypertext by a browser program.

FIG. 9 is a sequence diagram illustrating a flow of processing when sound data stored in the data storage server is sequentially reproduced by the client terminal.

FIG. 10 is a flowchart showing a processing procedure of a browser program when sound data stored in a data storage server is sequentially reproduced by a client terminal.

FIG. 11 is a flowchart showing a processing procedure of a data relay program when sound data stored in a data storage server is sequentially reproduced by a client terminal.

FIG. 12 is a flowchart showing a detailed processing procedure of communication processing performed in step 75 of FIG. 11;

FIG. 13 is a flowchart showing a detailed processing procedure of a data conversion (compression) process performed in step 85 of FIG. 12;

FIG. 14 is a flowchart showing a detailed processing procedure of sound data relay processing performed in step 86 of FIG. 12;

FIG. 15 is a flowchart showing another detailed processing procedure of the communication processing performed in step 75 of FIG. 11;

FIG. 16 is a flowchart showing a detailed processing procedure of sound data relay processing performed in step 286 of FIG. 15;

FIG. 17 is a flowchart showing a processing procedure of a proxy server program when sound data stored in a data storage server is sequentially reproduced by a client terminal.

FIG. 18 is a flowchart showing a processing procedure of a stored data transmission program when sound data stored in a data storage server is sequentially reproduced by a client terminal.

FIG. 19 is a diagram illustrating sound data reception and reproduction when sound data stored in a data storage server is sequentially reproduced by a client terminal.
9 is a flowchart illustrating a processing procedure of a reproduction program.

FIG. 20 is a flowchart showing a detailed processing procedure of the packet reception / reproduction processing performed in step 135 of FIG. 19;

FIG. 21 is a flowchart showing a detailed processing procedure of a transmission delay dispersion observation process performed in step 149 of FIG. 20;

FIG. 22 is an explanatory view showing an example of a method of acquiring transmission delay time observation data in step 160 of FIG. 21;

FIG. 23 is an explanatory diagram showing an example of a sequence when a packet including sound data is transmitted and received.

FIG. 24 shows steps 155 and 15 of FIG.
FIG. 9 is an explanatory diagram showing an example of a sequence when the process of No. 6 is performed.

FIG. 25 is an explanatory diagram showing a format of a data request command transmitted from the client terminal to the data storage server via the data relay device.

FIG. 26 is an explanatory diagram showing a format of a data request response command transmitted from the data storage server to the client terminal via the data relay device.

FIG. 27 is an explanatory diagram showing the format of a data format notification command used when the data relay program notifies the sound data receiving / reproducing program of the data format of sound data.

FIG. 28 is an explanatory diagram showing a format of a reproduction permission / prohibition notification command used when a sound data reception / reproduction program notifies a data relay program of permission / prohibition of reproduction of sound data.

FIG. 29 is an explanatory diagram showing the format of a packet used for transmitting sound data from a data relay program to a sound data receiving / reproducing program.

FIG. 30 is an explanatory diagram showing a format of a data transmission completion notification command transmitted from the data relay program to the sound data receiving / reproducing program.

FIG. 31 is a sequence diagram showing the flow of processing when presenting data stored in a data storage server in a client terminal in a conventional network system.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Data storage server, 2 ... Network, 3 ... Data relay apparatus, 4 ... Client terminal, 10/20 ... Mouse, 11, 21 ... Keyboard, 12, 22 ... Display, 13, 23 ... CPU, 14, 24 ... Memory , 15,
25 storage device, 16, 26 internal bus, 17, 27 ...
Communication control unit, 28: audio decoding device, 29: audio output device, 30: stored data transmission program, 31: proxy server program, 32: data relay program, 33: browser program, 34: sound data reception / reproduction program, 36, 37: Anchor tag, 38: Button for sequential reproduction.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takao Shimada 1099 Ozenji Temple, Aso-ku, Kawasaki City, Kanagawa Prefecture, Ltd.System Development Laboratory, Hitachi, Ltd.

Claims (14)

[Claims] 1. A data storage server storing at least sound data, a client terminal presenting data stored in the data storage server, and transmission / reception between the data storage server and the client terminal. A data relay device that relays data is a network system connected via a network, and the data relay device transmits the sound data when the data received from the data storage server is sound data. Data relaying means for packetizing the data at a size corresponding to the data amount of the sound data reproducible in the fixed time at regular time intervals, and transmitting the packetized data to the client terminal. The client terminal comprises: Sound data reproducing means for sequentially reproducing the sound data contained in the packet received from the A network system, characterized in that: 2. A data storage server storing at least sound data, a client terminal presenting data stored in the data storage server, and transmission / reception between the data storage server and the client terminal. A data relay device for relaying data, the network system being connected via a network, the data relay device, when the request received from the client terminal is the sequential reproduction of sound data, Data relay means for packetizing the sound data received from the storage server at a predetermined time interval into a size corresponding to the data amount of the sound data that can be reproduced in the fixed time, and transmitting the packet to the client terminal; The client terminal transmits the sound data included in the packet received from the data relay device. A network system comprising sound data reproducing means for sequentially reproducing sound. 3. A data storage server that stores at least sound data and a client terminal that presents data stored in the data storage server via a network. A data relay device for relaying data transmitted / received to / from a client terminal, wherein when the data received from the data storage server is sound data, the sound data is transmitted at regular time intervals. A data relay device comprising: a data relay unit that packetizes the audio data into a size corresponding to the data amount of sound data that can be reproduced in time, and then transmits the packet to the client terminal. 4. A data storage server that stores at least sound data and a client terminal that presents data stored in the data storage server via a network. A data relay device for relaying data transmitted to and received from a client terminal, wherein when the request received from the client terminal is sequential reproduction of sound data, the sound data received from the data storage server is A data relay device comprising: a data relay unit that packetizes data at a predetermined time interval into a size corresponding to a data amount of sound data that can be reproduced in the predetermined time, and then transmits the packetized data to the client terminal. 5. The data relay device according to claim 4, wherein said data relay means includes, in the data received from said data storage server, display data for a user of said client to input a request for sound data. A data relay device that, if included, adds display data for a user of the client to input a request for sequential reproduction, and then transmits the data to the client terminal. 6. The data relay device according to claim 3, wherein the data relay means packetizes the data after reducing the data amount of the sound data received from the data storage server. Data relay device. 7. A data storage server storing at least sound data, a client terminal presenting data stored in the data storage server, and transmission / reception between the data storage server and the client terminal. In a network system in which a data relay device that relays data is connected via a network, when the data received from the data storage server is sound data, the sound data is installed in the data relay device. In order to make the data relay device function so as to include a data relay unit that packetizes data at a size corresponding to the data amount of sound data that can be reproduced in the fixed time at regular time intervals, and then transmits the packet to the client terminal. Recording medium on which the program is recorded. 8. A data storage server storing at least sound data, a client terminal for presenting data stored in the data storage server, and transmission / reception between the data storage server and the client terminal. In a network system in which a data relay device for relaying data is connected via a network, the data relay device is installed in the data relay device, and when the request received from the client terminal is a sequential reproduction of sound data, Sound data received from the storage server is packetized in a size corresponding to the data amount of the sound data that can be reproduced in the fixed time at regular time intervals, and a data relay unit for transmitting the packet to the client terminal is provided. A record in which a program for causing the data relay device to function is recorded. Body. 9. The recording medium according to claim 8, wherein said data relay means includes display data for a user of said client to input a request for sound data in data received from said data storage server. A recording medium for transmitting the data to the client terminal after adding display data for allowing the user of the client to input a request for sequential reproduction. 10. A recording medium according to claim 7, 8 or 9, wherein said data relay means reduces the data amount of the sound data received from said data storage server before packetizing. Recording medium. 11. A data storage server storing at least sound data, a client terminal presenting data stored in the data storage server, and transmission / reception between the data storage server and the client terminal. A data relay device for relaying data is installed on the client terminal in a network system connected via a network, and when packetized sound data is received from the data relay device, the packet is received. If the packet is received in an order later than the order in which it should be performed, the client terminal may be provided with sound data reproducing means for discarding the packet and sequentially reproducing sound data included in the packet not discarded. Recording medium on which a program for causing a computer to function is recorded. 12. A data storage server storing at least sound data, a client terminal presenting data stored in the data storage server, and transmission / reception between the data storage server and the client terminal. A data relay device for relaying data is installed in the client terminal in a network system connected via a network, and when packetized sound data is received from the data relay device, the packet is received. If the packet is received in an order after the order in which it should be performed, and if the unreproduced sound data exceeds a predetermined amount, the packet is discarded and included in the packet not discarded. The client terminal so as to include sound data reproducing means for sequentially reproducing the sound data being reproduced. Recording medium on which a program is recorded for causing. 13. The recording medium according to claim 12, wherein a prescribed amount of unreproduced sound data used by said sound data reproducing means to determine whether or not to discard a packet is determined by said data relay device. A transmission delay dispersion absorption time for correcting dispersion of transmission delay occurring on a network connected to the client terminal and a time corresponding to a time interval at which the data relay means packetizes sound data are added. The time is a data amount equal to or less than the data amount of sound data that can be reproduced by the sound data reproducing means, and the sound data reproducing means obtains the transmission delay dispersion absorption time based on a packet reception interval. Recording medium. 14. The recording medium according to claim 11, 12 or 13, wherein said sound data reproducing means, when a packet in the order to be received cannot be received, sets a time at which the next packet was received. If the time corresponding to the time interval at which the data relay device packetizes the sound data has elapsed since the time when the reproduction of the sound data included in the previously received packet was started, 1
A recording medium for reproducing silent data of a data amount corresponding to a packet.