JPH11231866A - Data communication device, communication method, communication system and medium with program recorded - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid congestion of communication lines by reducing data, received by a receiving means, to transmit data to lines in access according to the number of lines in access. SOLUTION: A rooter 6 transmits MIDI data and image data from a performance hall 1. A relay server 12 adjusts the quantity of data supplied from a main server 7 according to the congestion degree of communication lines and supplies data to a WWW server 8. When the number of users (the number of lines) getting access to the relay server 12 is large, it is so judged that the communication lines are congested, and data is thinned out to reduce the data quantity. The decrease of the data quantity can avoid the congestion of the communication lines. Since MIDI data and voice data are more important information for the users than image data, the MIDI data and voice data are processed preceding the image data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data communication technique, and more particularly to a data communication technique capable of avoiding congestion of a communication line.

[0002]

2. Description of the Related Art As a unified standard for communication between electronic musical instruments, M
There is an IDI (music instrumental digital interface) standard. An electronic musical instrument having a MIDI standard interface can be connected to another electronic musical instrument using a MIDI cable. The electronic musical instrument can communicate MIDI data via a MIDI cable.

For example, one electronic musical instrument can transmit information played by a player as MIDI data, and another electronic musical instrument can receive the MIDI data and generate musical tones. Playing on one electronic musical instrument can produce real-time sound on another electronic musical instrument.

In a communication network connecting a plurality of general-purpose computers, various types of information can be communicated. For example, information such as raw musical sound information and MIDI data can be stored once in a hard disk or the like connected to a computer, and the information can be transmitted via a communication network. Another computer receives the information and stores it in a storage device such as a hard disk. A general-purpose communication network only communicates information, and has a different property from MIDI.

[0005]

The MIDI standard allows for real-time communication between electronic musical instruments, but is not suitable for long-distance communication and communication between multiple nodes. On the other hand, the general-purpose communication network is suitable for long-distance communication and communication between many nodes, but does not consider real-time communication between electronic musical instruments.

When real-time communication of musical sound information is performed, the amount of information per time increases, and the communication line tends to be congested. Further, compared to the one-to-one communication, when the musical sound information is transmitted to a large number of nodes, the communication line becomes more congested. If the communication line is congested, the communication speed will be delayed, which will hinder real-time performance.

An object of the present invention is to provide a data communication technique capable of avoiding congestion of a communication line.

[0008]

According to one aspect of the present invention, there are provided receiving means for receiving data, access number recognizing means for recognizing the number of lines which are accessing itself from outside,
There is provided a data communication device comprising: a transmitting unit that reduces data received by the receiving unit according to the number of lines and transmits the data to a line being accessed.

When a large number of lines are being accessed,
By reducing and transmitting the received data, it is possible to reduce the congestion of the line. When the number of access lines is small, it is not always necessary to reduce the data.

According to another aspect of the present invention, there is provided a communication system including a plurality of communication devices each having a reception unit and a transmission unit, wherein the reception unit receives the same data in each of the plurality of communication devices. The transmitting unit in the plurality of communication devices is a unit that can reduce and transmit the data received by the receiving unit, and the data to be reduced by one communication device and the data to be reduced by another communication device. A communication system is provided that differs from data to be reduced.

Since data to be reduced by one communication device is different from data to be reduced by another communication device, the quality of data transmitted by each communication device is different. With the communication device, for example,
The amount of data to be reduced and the data target are different. The user
By selecting a communication device to access, data having a desired quality can be obtained.

[0012]

FIG. 1 is a diagram showing a communication network for music information.

The performance hall 1 is provided with a MIDI musical instrument 2, a camera 4, encoders 3 and 5, and a router 6. In the performance hall 1, a player plays a MIDI musical instrument 2. M
The IDI musical instrument 2 generates MIDI data according to the performance operation of the player and supplies the MIDI data to the encoder 3. Encoder 3
Transmits a packet of MIDI data in a predetermined data format to the Internet via the router 6. The data format will be described later with reference to FIG.

The camera 4 captures an image of a player performing, and supplies the captured image to the encoder 5 as image data. The encoder 5 transmits a packet of image data in a predetermined data format to the Internet via the router 6. The microphone 13 is a live instrument such as a vocal or a piano,
The audio of the electric musical instrument is sampled, and the sampled data is supplied to the encoder 14 as audio data. The encoder 14 transmits voice data to the Internet via the router 6 in a predetermined data format. The data format will be described later with reference to FIG.

The router 6 transmits MIDI data and image data via the Internet described below. The data is supplied from the router 6 to the main server 7 through a telephone line or a dedicated line, further supplied to a plurality of relay servers 12a, 12b, 12c,.
It is supplied to a WW (world wide web) server 8. WWW
The server 8 is a so-called provider.

Hereinafter, the relay servers 12a, 12b, 12
All or each of c,... The relay server 12 has a role of avoiding congestion of the communication line. The relay server 12, depending on the degree of communication line congestion,
By adjusting the amount of data supplied from the main server 7,
The information is supplied to the WW server 8. For example, when the number of users (the number of lines) accessing the relay server 12 is large, it is determined that the communication line is congested, and data is thinned out.
Reduce the amount of data. By reducing the amount of data, congestion of the communication line can be avoided.

A plurality of relay servers 12a, 12b, 12c
Can have different data reduction amounts or reduction methods. The amount of data reduction affects sound quality or image quality based on the data. As the amount of reduction increases, the sound quality or image quality decreases.

For example, in the relay server 12a, the number of users who can access can be reduced, and the sound quality and the image quality can be improved. In the other relay server 12c, the number of users who can access can be increased by suppressing sound quality and image quality. By the function of the relay server 12, congestion of the communication line can be reduced.

The user connects the home computer 9 to the WWW
By connecting to the server 8, the Internet can be used. The home computer 9 can receive MIDI data, image data, and audio data in real time using the Internet. The home computer 9 has a display device and a built-in or external MIDI sound source, can display image data on the display device, and can cause the MIDI sound source to generate a musical tone signal. The MIDI sound source generates a tone signal based on the MIDI data, and outputs the tone signal to the audio output device 11. The audio output device 11 has a D / A converter, an amplifier, and a speaker, and emits sound in accordance with the tone signal. or,
The audio data is reproduced, and after D / A conversion, passes through an amplifier and is reproduced as audio from a speaker. A sound equivalent to the performance sound performed in the performance hall 1 is output from the audio output device 11.
Is pronounced in real time.

Further, M
If the IDI sound source 10 is connected, the home computer 9
Can cause the MIDI sound source 10 to generate a tone signal and cause the sound output device 11 to generate a tone.

Since the MIDI data and the audio data are more important information for the user than the image data, the processing is performed by giving priority to the MIDI data and the audio data over the image data. Image data has poor image quality,
Although it does not matter much if the number of frames is small, high-quality tone information and audio information based on MIDI data and audio data are required.

Anyone can listen to the performance by connecting the home computer 9 at home to the Internet. Further, the user can listen to the performance in real time while staying at home and watching the scene of the performance hall 1 on the display device without going to the performance hall 1. When a concert is performed at the performance hall 1, an unspecified number of people can enjoy the concert at home.

By transmitting the MIDI data from the performance hall 1 to the user's home, it is possible to create a situation as if the performer is playing (operating) an electronic musical instrument at each of a plurality of users' homes. .

[0024] The organizer of the concert can determine the capacity of the concert and issue tickets to the user.
Tickets include, for example, rank A (special seat), rank B
(Normal seat), rank C (standing seat), and the like. A user of rank A can access the relay server 12a, and high-quality musical sound information and image information can be obtained. The user of rank B can access the relay server 12b, and can obtain tone information and image information with reduced data amount. A user of rank C can access the relay server 12c, and can obtain only tone information with a reduced data amount, but cannot obtain image information.

Further, since the Internet communicates MIDI data instead of live musical sound information, noise does not lower the sound quality. However, since the Internet performs long-distance communication and passes through various communication points, it is necessary to take the following countermeasures against communication errors when transmitting data in the encoders 3 and 5 and receiving data in the home computer 9. Communication errors are
For example, garbled data, missing data, duplicated data, rearranged data order, and the like.

FIG. 2 is a diagram showing a hardware configuration of the encoders 3 and 5 and the home computer 9. For these, a general-purpose computer can be used.

The bus 31 includes an input device 26 such as a keyboard and a mouse, a display 27, a MIDI sound source 28, a communication interface 29 for performing the Internet, and a MID.
I interface 30, RAM21, ROM22, C
The PU 23 and the external storage device 25 are connected.

The input device 26 can instruct various settings. In the home computer 9, the display 27 displays a pattern of the performance hall, and the MIDI sound source 28 generates a tone signal based on the received MIDI data, and outputs the signal to the outside.

The communication interface 29 is an interface for transmitting and receiving MIDI data and image data via the Internet. The MIDI interface 30 is an interface for transmitting and receiving MIDI data to and from the outside.

The external storage device 25 includes, for example, a hard disk drive, a floppy disk drive, a CD-RO
M drive, magneto-optical disk drive, etc.
I data, image data, computer programs, and the like can be stored.

The ROM 22 can store computer programs and various parameters. RAM 21
Are the key-on buffer 21a and the sound source setting buffer 21b
Having. The key-on buffer 21a stores a key-on event in the MIDI data, and
b stores the sound source setting information in the MIDI data.

The RAM 21 has other working areas such as buffers and registers, and can copy and store the contents stored in the ROM 22 and the external storage device 25. The CPU 23 is a ROM 22 or a RAM 21
Performs various calculations or processes according to the computer program stored in the. The CPU 23 can obtain time information from the timer 24.

The external storage device 25 is, for example, a hard disk drive (HDD). The HDD 25 can store various data such as operation programs and MIDI data. When the operation program is not stored in the ROM 22, the operation program is stored in the hard disk in the HDD 25, and is read into the RAM 21 so that the same operation as when the operation program is stored in the ROM 22 is performed by the CPU 23. Can be done. By doing so, it is possible to easily add an operation program or upgrade the version. Also, the external storage device 25
Is a CD-ROM including an HDD and a CD-ROM (Compact Disc-Read Only Memory) drive
The drive can read operation programs and various data stored in the CD-ROM. The read operation program and various data are stored in a hard disk in the HDD. New installation and version upgrade of the operation program can be easily performed. Note that this C
In addition to the D-ROM drive, a floppy disk drive, a magneto-optical disk (M
O) A device for using various forms of media, such as a device, may be provided.

The communication interface 29 is connected to a communication network 32 such as a LAN (local area network), the Internet or a telephone line, and is connected to a server computer 33 via the communication network 32. If the above operation program and various data are not stored in the HDD 25, the server computer 33
Used to download programs and data from The encoders 3 and 5 or the home computer 9 serving as a client transmits a command for requesting download of an operation program or data to the server computer 33 via the communication interface 29 and the communication network 32. Upon receiving this command, the server computer 33 converts the requested operation program and data into
The program is distributed to the encoders 3 and 5 or the home computer 9 via the communication network 32, and the encoder 3 and 5 or the home computer 9 receives these programs and data via the communication interface 29 and
, The download is completed.

The present embodiment may be implemented by a commercially available personal computer or the like in which an operation program and various data corresponding to the present embodiment are installed. In that case, the operation program and various data corresponding to the present embodiment may be provided to the user in a state where the program is stored in a storage medium such as a CD-ROM or a floppy disk which can be read by a personal computer. When the personal computer or the like is connected to a communication network such as a LAN, the Internet, or a telephone line, the operation program or various data may be provided to the personal computer or the like via the communication network.

FIG. 3 is a diagram showing measures against a MIDI data communication error. In the figure, the key-on state is schematically represented by a high level, and the key-off state is represented by a low level.

A case where a key-on is transmitted at time t1 and a key-off is transmitted at time t4 will be described. The key-on transmitted at time t1 causes a communication error,
May be missing. In that case, the home computer 9 on the receiving side does not receive the key-on, but receives only the key-off. In this case, a normal performance cannot be reproduced. It is impossible according to playing rules that a key-on is not generated and only a key-off is generated.

To avoid such a situation, the time t1
After the transmission of the key-on, the recovery key data is transmitted each time a predetermined time elapses, that is, at time t2 and time t3.

The recovery key data is data for confirming that the key is currently on. Even if the key-on at time t1 is not received, time t2
By receiving the recovery key data at
Although it is slightly delayed from time t1, the key can be turned on. Further, even when the data at both times t1 and t2 cannot be received, the key can be turned on by the recovery key data at time t3.

However, the tone signal generally attenuates over time. Therefore, when transmitting the recovery key data, it is preferable to transmit a key-on with reduced velocity (volume) in consideration of the passage of time. Specifically, a key-on with a gradually reduced velocity may be transmitted in the order of times t1, t2, and t3.

The key-on communication error can be recovered by the recovery key data. next,
A recovery method when a key-off at time t4 causes a communication error will be described.

After the key-off occurs, it is possible to transmit the key-off recovery data in the same manner as the key-on. However, for each key, the time during key-off is significantly longer than the time during key-on. Once the recovery data is sent to the next key-on after the key-off, the data amount becomes enormous.

The key-on recovery key data is transmitted from the key-on time t1 to the key-off time t4,
It is not transmitted after time t4. That is, the fact that the recovery key data is not transmitted means that key-off has already occurred. If home computer 9 is at time t4
When the key-off at the time of is not received, it is sufficient to confirm that the recovery key data is not transmitted thereafter, and determine that the key-off is being performed at present.

When the recovery key data is no longer transmitted even though the key is currently on, the home computer 9 can prevent the phenomenon in which the key is turned off and the sound continues to sound erroneously. These determinations are made by referring to the key-on buffer 21a in FIG. Details will be described later with reference to a flowchart.

As in the case of key-on / off, by referring to the sound source setting buffer 21b in FIG. 2, it is possible to communicate the recovery sound source setting information for recovering the sound source setting information.

FIG. 4 is a diagram showing a format of a communication packet. The encoders 3 and 5 in FIG. 1 transmit the packet, and the home computer 9 receives the packet.

The packet includes a header section 41 and a data section 42.
Consists of The header section 41 has two words (one word is 16 words).
Bit) checksum 43, 4-word data ID 4
It has a sequence number 45 of 4, 4 words, time information 46 of 4 words, and an event data length 47 of 2 words.

The checksum 43 is the total value of the data in the header section 41 and the data section 42 excluding the checksum.
The transmitting side calculates the total value and adds it as a checksum 43 in the packet. The receiving side can calculate the total value and confirm that there is no communication error if the total value matches the value of the checksum 43.

The data ID 44 indicates the type of the data section 42 by a number. Numbers 0, 1, and 2 are MIDI data,
Number 3 is image data, and number 4 is audio data. In the MIDI data, the number 0 is data of an actual event (normal MIDI data), the number 1 is recovery key data (FIG. 3), and the number 2 is recovery sound source setting information.

The sequence number 45 is a sequence number given in packet units. By confirming the sequence number 45, the receiving side can recover even if the order of data is changed due to a communication error.

The time information 46 is a reproduction time in which one bit indicates 1 ms. With four words, time information of 100 hours or more can be expressed. Using the time information 46 enables simultaneous sessions at a plurality of performance venues.
If the performance time is given as time information 46 for each performance venue, simultaneous performances can be heard at home while synchronizing the performance venues. The time information 46 is preferably an absolute time, but may be a relative time as long as the time is common to all the performance venues.

The event data length 47 indicates the data length of the data section 42. The data section 42 includes actual data 48. The actual data 48 is MIDI data or image data.

The communication speed is preferably high.
For example, 64 Kbit / s (ISDN line). The data length of one packet is not limited, but is preferably about 1 Kbyte or 512 bytes in consideration of communication efficiency.

FIG. 5 is a flowchart showing a transmission process performed by the encoder 3. In step SA1, M
The MIDI data is received from the IDI musical instrument 2. At Step SA2, the received data is buffered in the RAM.

At step SA3, the type of the event of the received data is identified. If it is a key-on, the process proceeds to Step SA6, where the key-on is performed by the key-on buffer 21a
(FIG. 2) and proceed to step SA7.

If the key is off, the flow advances to step SA4 to search the key-on buffer 21a. If the same key code is found, the key-on is detected by the key-on buffer 21a.
Remove from. Thereafter, the flow advances to Step SA7.

If it is sound source setting information, the process proceeds to step SA5, where the sound source setting information is registered in the sound source setting buffer 21b (FIG. 2), and the process proceeds to step SA7. The sound source setting information is program change, control data, exclusive message, and other data.

In step SA7, as shown in FIG.
A checksum 43, a data ID 44 indicating actual event data (number 0), a sequence number 45, time information 46 corresponding to a timer, and an event data length 47 are added to the received MIDI data, packetized and transmitted. At this time, a plurality of events of the same type that occurred at substantially the same time can be collectively packetized and transmitted.
Thereafter, the transmission process ends.

Note that the encoder 5 transmits image data in the same manner as the above processing. In that case, data ID
The number 44 is 3.

FIGS. 6A and 6B are flowcharts showing the interrupt processing performed by the encoder 3. FIG. The interrupt processing is performed at predetermined time intervals according to the timer.
For example, interrupt processing is performed at intervals of 100 to 200 μs.

FIG. 6A is a flowchart showing the transmission processing of the recovery key data.

In step SB1, the key-on buffer 2
1a (FIG. 2). In step SB2, the event data in the key-on buffer 21a is packetized and transmitted as recovery key data as shown in FIG. However, the recovery key data sets a velocity that is lower than the key-on in the key-on buffer 21a in consideration of the passage of time.

The data ID 44 in the packet is number 1 indicating the recovery key data. The sequence number 45 is a common sequence number between the actual event data (FIG. 5) and the recovery key data (FIG. 6A). After the transmission, the process returns to the process before interruption.

FIG. 6B is a flowchart showing the transmission processing of the recovery sound source setting information. Since the transmission process does not require relatively high temporal accuracy, the transmission process may be performed at a longer cycle than the transmission process of the recovery key data (FIG. 6A).

In step SC1, the sound source setting buffer 2
1b (FIG. 2). In step SC2, the event data in the sound source setting buffer 21b is packetized and transmitted as recovery sound source setting information as shown in FIG.

The data ID 44 in the packet is the number 2 indicating the recovery sound source setting information. The sequence number 45 includes actual event data (FIG. 5), recovery key data (FIG. 6A), and recovery sound source setting information (FIG. 6).
(B)). After the transmission, the process returns to the process before interruption.

FIG. 7 is a flowchart showing a receiving process performed by the home computer 9. At step SD1, data on the Internet is received. In step SD2, the checksum 43 (FIG. 4) in the packet is confirmed.

At step SD3, the result of the checksum is checked. If the checksum is an error, it indicates that there is an error in the data in the packet, so the process proceeds to step SD9, and the process ends without doing anything. It is effective to discard unreliable data to eliminate erroneous pronunciations and settings.

If the checksum is normal, since the data is reliable, the process proceeds to step SD4. Step SD
4, the sequence number 45 in the packet (FIG. 4)
Check. In normal communication, the sequence number 45 is sequentially increased each time reception is performed, but the order of received data may be changed due to a communication error.

At step SD5, it is checked whether the received data is the sequence number 45 to be reproduced and the current time of the home computer 9 is after the time information 46 (FIG. 4) to be reproduced. When a simultaneous session is performed at a plurality of performance venues, the time information 46 of a certain performance venue may not yet be the time to be reproduced.

If it is not to be reproduced yet, the process proceeds to step SD10, where the received data is buffered in the RAM, and the data is prepared for processing at an appropriate timing later. After that, the process ends.

When playback is to be carried out, step SD
Proceed to 6 to perform event processing. Event processing is
This is processing according to an event such as DI data or image data. The details will be described later with reference to the flowchart of FIG.

At step SD7, the sequence number is counted up. In step SD8, the data in the buffer buffered in step SD10 is
It is checked whether there is a sequence number 45 to be reproduced and the current time is after time information 46 to be reproduced.

If there is nothing to be reproduced, the process is terminated. When there is something to be reproduced, step SD
Then, the process goes to 6 to repeat the process for the data. This process is repeated until there is no more data to be reproduced in the buffer. By this processing, data received in a different order of data due to a communication error can be appropriately processed.

When data of a predetermined number or more is accumulated in the buffer, it is determined that the data of the next sequence number to be processed is missing, the processing of that data is skipped, and the processing of the data of the next sequence number is skipped. Advance.

FIG. 8 is a flowchart showing details of the event processing shown in step SD6 of FIG.

At step SE1, the number of the data ID is identified. If the number is 0, it indicates actual event data, and the flow advances to step SE2. In step SE2, the type of the event is identified.

If it is a key-on, the process proceeds to step SE3, where the key-on is registered in the key-on buffer 21a (FIG. 2) and transferred to the sound source. The sound source receives the key-on,
Performs processing to start pronunciation. Thereafter, the process returns to the process of FIG.

If the key is off, the process proceeds to step SE4, where the key-on buffer 21a is searched. If the same key code is found, the key-on in the key-on buffer 21a is deleted and the key-off is transferred to the sound source. Upon receiving the key-off, the sound source performs a process for silencing. Thereafter, the process returns to the process of FIG.

If it is the sound source setting information, the process proceeds to step SE5, where the sound source setting information is registered in the sound source setting buffer 21b and transferred to the sound source. The sound source receives the sound source setting information and sets the timbre, volume, and the like. Thereafter, the process returns to the process of FIG.

If the data ID number is 1, it means that the received data is recovery key data, and the flow advances to step SE6. The recovery key data is compared with the current key-on buffer 21a, the difference is converted into an event, registered in the key-on buffer 21a, and transferred to the sound source. By this processing, a key-on lost due to a communication error can be recovered.

In step SE7, the fact that the recovery key data has been received is registered. After the key-off, the recovery key data is no longer transmitted, so by performing this registration, it is possible to confirm that the corresponding key-on is still on. If recovery key data is no longer transmitted even though a key-on exists in the key-on buffer, it indicates that key-off is missing. Thereafter, the process returns to the process of FIG.

If the data ID number is 2, it means that the received data is the recovery sound source setting information,
Proceed to step SE8. The recovery sound source setting information is compared with the current sound source setting buffer 21b, the difference is converted into an event, registered in the sound source setting buffer 21b, and transferred to the sound source. By this processing, the sound source setting information missing due to the communication error can be recovered.

If the data ID number is 3, it means that the received data is image data, and step SE
Go to 9. In step SE9, a process of displaying the image data on a display is performed. However, the image data is
Processing is performed with a lower priority than DI data. The image to be displayed is processed in principle for one screen.
In order to give priority to MIDI data, the image may be a still image. Thereafter, the process returns to the process of FIG. If the data ID is 42, it means that the received data is audio data,
Proceed to step SE10. In step SE10, a process of reproducing the audio data is performed.

FIG. 9 is a flowchart showing an interrupt process performed by the home computer 9. The interrupt processing is performed at predetermined time intervals according to a timer. For example, interrupt processing is performed at intervals of 100 to 200 μs.

At step SF1, the key-on buffer 2
1a (FIG. 2). In step SF2, among the key-ons in the key-on buffer 21a that do not receive the corresponding recovery key data for a certain period of time, the key-on is deleted and the corresponding key-off is transferred to the sound source. After the transfer, the process returns to the process before the interruption. This fixed time may be a time sufficient to receive at least two subsequent recovery data.

By this processing, it is possible to prevent the sound from being erroneously continued even when the key-off is lost due to a communication error. It should be noted that the determination of not receiving the recovery key data for a certain period of time can be made by registering the reception of the recovery key data in step SE7 in FIG.

By transmitting the above-mentioned recovery key data and recovery sound source setting information (both are collectively referred to as recovery data), it is possible to perform appropriate recovery even when data is lost or corrupted. it can.

Next, a method for alleviating line congestion will be described. When the performance information and the recovery data are communicated over a network, a considerable amount of data flows through the line. In addition, when the above-mentioned concert is performed, the number of users accessing the server at the same time becomes considerable.

Under such circumstances, it may not be possible to guarantee the smooth reproduction of the performance on the home computer owned by the user. Therefore, as shown in FIG. 1, a plurality of relay servers are provided, and each relay server independently reduces data according to the degree of congestion of the line, thereby alleviating the congestion of the line.

However, when data is reduced, sound quality or image quality is reduced. Therefore, the relay server can set a data reduction rate and a reduction method that can be independently allowed, and the number of users who can access the relay server.

When the number of accesses to the relay server is small, the relay server can transmit the data to the user without reducing the data, and when the number of accesses increases, the data can be reduced and transmitted to the user.

The following are methods for reducing data. (1) Separation of data The relay server receives musical sound information (MIDI data), image information (image data), and audio information (audio data). Since the image information does not require much data quality as compared with the tone information and the voice information, the relay server separates the received information into the tone information and the voice information and the image information, and outputs only the tone information and the voice information to the user. Can be sent to Similarly, data in musical sound information, audio information or image information may be further finely separated and only necessary data may be transmitted. By transmitting only important information and reducing data, it is possible to reduce the congestion of the line.

(2) Data Differentiation The relay server defines the priority of data and transmits important data preferentially. That is, when the line is congested, only important data is transmitted at that time, and unimportant data is transmitted later with a delay to reduce the line congestion. In this method, the data amount is not necessarily reduced as a whole, but the data amount to be transmitted at that time is reduced.

For example, missing key-off is a more fatal error than missing key-on. That is, the key-off information has a high data importance. The relay server divides the received packet into a key-off and other data, transmits the former first, and then transmits the latter.

When a key-on and a corresponding key-off exist in the same packet, it is inconvenient to divide the key-on and the key-off, transmit the key-off first, and then transmit the key-on. It is preferable not to send. Similarly, when there is an inconvenience of preferential transmission, a process corresponding to the inconvenience is required.

(3) Data resolution operation The relay server reduces the data resolution and transmits the data to the user to reduce the data amount. For example, when the volume increases by one step over time, the resolution of the data is reduced, the data that increases by two steps is transmitted, and the data amount is halved. In addition to the volume, the resolution of control data (controller data) such as pitch bend and after touch can be reduced. Different resolutions may be set according to the type of controller, and the resolution of a plurality of control data may be reduced.

(4) Time resolution operation The above recovery data is transmitted periodically. The relay server lengthens the transmission cycle of the recovery data,
Reduce the amount of recovery data. Further, the image transmission rate can be reduced. For example, by reducing the number of frames from 8 frames to 4 frames per second, the data amount can be reduced.

Next, the relay server will be described. The relay server has the same configuration as the computer shown in FIG. However, the sound source 28 and the MIDI interface 30 are not always necessary.

FIG. 10 shows the configuration of the RAM included in the relay server 12 shown in FIG. A plurality of relay servers 12a, 1
2b and 12c respectively store the following information in the RAM.

(1) Current Access Number 51 The current access number 51 indicates the number of users (the number of lines) currently accessing their own relay server, and changes according to the access situation. The number of accesses is initially 0, increases each time the user starts access, and decreases when the access is released.

(2) Overflow Flag 52 The overflow flag 52 is a flag indicating whether or not the relay server has overflowed. Initially,
The overflow flag 52 is set to 0. The fact that the overflow flag 52 is 0 indicates that overflow has not occurred. When the number of users accessing the relay server reaches the allowable access number 54 described later, the overflow flag 52 becomes 1.

(3) Current thinning coefficient 53 The current thinning coefficient 53 indicates the thinning coefficient currently set. The thinning coefficient is a coefficient indicating a rate of data reduction (hereinafter, also referred to as thinning) and a thinning method. The thinning coefficient 53 is initially set to 0. When the thinning coefficient 53 is 0, it indicates that no thinning is performed. Table 1 shows an example of the thinning coefficient.

[0104]

[Table 1] Note that a combination of the above thinning coefficients may be used as one thinning coefficient.

(4) Permitted Number of Accesses 54 Permitted number of accesses 54 indicates the maximum value of the number of users (number of lines) that can access the relay server, and can be set to an arbitrary constant. The allowable number of accesses 54 corresponds to the capacity of the relay server.

(5) Allowable Thinning Coefficient 55 The allowable thinning coefficient 55 indicates the maximum value of the thinning coefficient allowable in the relay server. For example, the thinning-out coefficient corresponds to the thinning-out rate, and the thinning-out rate increases as the coefficient increases. An acceptable degree of thinning can be determined for each relay server according to the number of accesses.

(6) Table Number 56 The table number 56 indicates the number of the table that associates the number of accesses with the thinning coefficient. FIG. 11 shows examples of characteristic lines 60a, 60b, and 60c indicating three types of tables. The table associates the number of accesses with a thinning coefficient. It is preferable that the amount of data reduction increases as the number of accesses increases. The characteristic line 60 does not need to be a continuous value represented by a line, but may be a discrete value. Also, since the size of the thinning coefficient does not necessarily indicate the amount of data reduction, as the number of accesses increases,
It is not always necessary to increase the thinning coefficient. These tables are stored in memory.

A plurality of tables are prepared (for example,
The table numbers 56 are the three types of tables 60a, 60b, and 60c), and the number of the table that is optimal for the own relay server.

(7) Next candidate relay server address 57 The next candidate relay server address 57 indicates the address of another relay server to which a transfer is made when the relay server overflows. When a user accesses a relay server, if the relay server overflows, the server automatically shifts to the relay server indicated by the next candidate relay server address.

FIG. 12 is a flowchart showing the processing of the relay server performed when the user accesses the relay server.

In step SG1, when an access from a user (client) is detected, the process proceeds to step S1.
The processing after G2 is performed. By accessing the relay server, the user can obtain musical sound information, audio information, or image information.

In step SG2, it is checked whether the overflow flag 52 (FIG. 10) is 0 or 1. When the overflow flag is 1, since the number of accesses to the self exceeds the allowable number of accesses, the process proceeds to step SG6.

In step SG6, the address is moved to another relay server according to the next candidate relay server address 57 (FIG. 10). That is, the access of the user is automatically transferred to another relay server. As a result, the user accesses the other relay server. If the other relay server also overflows, it is moved to another relay server. In this way, when the accessed relay server is congested,
It is automatically moved to another relay server that is not crowded. The relay server ends the process after the transfer to another relay server.

If it is determined in step SG2 that the overflow flag is 0, it means that the number of accesses to the relay server is smaller than the allowable number of accesses, and the process proceeds to step SG3.

At step SG3, the current access number 5
1 (FIG. 10) is incremented. Number of access 51
Indicates the number of users accessing their own relay server. Each time the relay server grants access from the user,
The number of accesses 51 is incremented.

Next, using the table (FIG. 11) indicated by the table number 56 (FIG. 10), a thinning coefficient corresponding to the access number 51 is obtained, and is written in the memory as the current thinning coefficient 53. When the thinning coefficient does not change, writing may be omitted. When the number of accesses increases, a thinning coefficient having a high thinning rate is selected.

In step SG4, the current number of accesses 5
It is checked whether 1 has reached the allowable access number 54 (FIG. 10). When it has reached, proceed to step SG5,
The overflow flag 52 is set to 1 so that the number of accesses is not further increased. If not, the overflow flag is left at 0. afterwards,
The process ends.

FIG. 13 is a flowchart showing the processing of the relay server performed when the user releases the access to the relay server.

In step SH1, when it is detected that the user (client) has released the access, the processing after step SH2 is performed.

At step SH2, the current number of accesses 5
1 (FIG. 10) is decremented. The relay server decrements the access number 51 each time the user releases the access.

Next, using the table (FIG. 11) indicated by the table number 56 (FIG. 10), a thinning coefficient corresponding to the access number 51 is obtained, and is written to the memory as the current thinning coefficient 53. When the thinning coefficient does not change, writing may be omitted. When the number of accesses decreases, it is possible to change to a thinning coefficient with a low thinning rate.

At step SH3, it is checked whether the overflow flag 52 (FIG. 10) is 0 or 1. When the overflow flag is 1, the process proceeds to step SH4, where the overflow flag is set to 0, so that a new access can be accepted. Overflow flag is 0
, The overflow flag is kept at 0. After that, the process ends.

Note that the overflow flag is set to 0 without checking the overflow flag in step SH3.
Or the overflow flag may be set to 1. In this case, the same operation as described above can be performed.

FIG. 14 is a flowchart showing the processing of the relay server when the relay server receives data from the main server.

At step SI1, data is received from the main server 7 (FIG. 1) in packet format. Data is,
It includes musical sound information (including recovery data), audio information, and image information. The relay server receives the unthinned data. A plurality of relay servers all receive the same data.

In step SI2, the current thinning coefficient 5
3 (FIG. 10) to determine the thinning method (state). For example, if the thinning coefficient is 0, data thinning is not performed (Table 1).

In step SI3, predetermined data is deleted from the data section 42 (FIG. 4) of the received packet according to the determined thinning method.

In step SI4, the packet header section 4
The checksum 43, the data length 47, etc. of 1 (FIG. 4) are rewritten. The checksum 43 and the data length 47 are rewritten to those corresponding to the data after the above-mentioned predetermined data has been deleted.

In order to simplify the processing, the sequence number 45 and the time 46 in the packet need not be rewritten. Conversely, when it is desired to improve the data quality, the sequence number 45 and the time 46 may be rewritten to appropriate values. By performing rewriting, communication errors such as data loss and replacement can be more fully recovered.

At step SI5, the rewritten packet is transferred to the WWW server 8 (FIG. 1). The WWW server receives the data for which the predetermined thinning has been performed. The plurality of relay servers can receive the same data from the main server 7, perform different thinning-out, and transfer the same to the WWW server 8. This is the end of the process.

FIG. 15 is a flowchart showing the processing of the relay server when the relay server thins out the recovery data.

In step SJ1, it is checked whether or not the packet received from the main server 7 is recovery data. The check is performed with the data ID 44 (FIG. 4).
Is performed by referring to. Data ID value is 1 or 2
If so, it is recovery data. Since this flowchart is for thinning out the recovery data, the process ends immediately when data other than the recovery data is received. When the recovery data has been received, the process proceeds to step SJ2.

In step SJ2, the register recov
It is checked whether the value of er_timer is greater than the time specified by the thinning coefficient. Register recov
er_timer indicates the elapsed time since the previous recovery data was received. The time specified by the thinning-out coefficient corresponds to a period for transmitting the recovery data.

The register recover_timer is:
When the thinning coefficient is larger than the designated time, the process proceeds to step SJ3.

At step SJ3, the received packet is transferred to WWW server 8 as it is. Step SJ
In step 4, 0 is set in the register recover_timer, and the process is terminated.

The register recover_timer is:
Thereafter, the count is incremented at predetermined time intervals by an interrupt process. The interrupt processing is performed by the timer 24 shown in FIG.
Is instructed to start processing at predetermined time intervals.

At step SJ2, register reco
If the ver_timer is not greater than the time specified by the thinning coefficient, it means that the predetermined time has not yet elapsed, and the process proceeds to step SJ5.

In step SJ5, all data portions of the received packet are deleted, and only the header portion is left. In step SJ6, the packet consisting of only the above header
The data is transferred to the WW server 8, and the process is terminated.

Although the case where the header portion is transferred in the above processing has been described, the data amount may be further reduced by not transferring the packet itself. However, in this case, it is necessary to determine whether the packet has been deleted due to thinning or the packet has been lost due to a communication error. It is necessary to recover data when a packet is lost due to a communication error, but it is not necessary to recover data when a packet is deleted by thinning.

Also, the register recover_time
Instead of counting up the value of r by interrupt processing, the number of times recovery data is received from the main server may be counted. For example, when receiving the recovery data from the main server three times, the first and second data are transferred without deleting the recovery data, and the third data is transferred without deleting the recovery data. According to this processing, it is not necessary to count up the value of the register recover_timer by the interrupt processing.

FIG. 16 is a flowchart showing a process performed by the relay server when the relay server preferentially transmits a key-off.

In step SK1, key-off data is extracted from the packet received from the main server, and the flow advances to step SK2. When the key-off data is not included in the packet, the received packet is
Transfer to WW server.

In step SK2, a new packet is created in which only the extracted key-off data is used as the data portion.

At Step SK3, the newly created packet is transferred to the WWW server.

In step SK4, the received packet from which the key-off data has been deleted is transferred to the WWW server, and the process ends. That is, the data in the packet is separated into key-off data and other data, and the key-off data is transferred preferentially in step SK3.
Other data is transferred at K4.

By delaying the transfer time in step SK4 as compared with the transfer time in step SK3, the data can be transferred in a distributed manner. Congestion can be reduced.

FIG. 17 is a flowchart showing the processing of the relay server when the relay server deletes and transfers the image data.

At step SL1, it is checked whether the packet received from the main server is image data. This check is performed by referring to the data ID 44 (FIG. 4). If the value of the data ID is 3, it is image data. Since this flowchart is for deleting image data, when data other than image data is received, the process is immediately terminated. When the image data has been received, the process proceeds to step SL2.

In step SL2, all data portions in the received packet are deleted, and only the header portion is left. At step SL3, the packet consisting of only the above-mentioned header portion is transferred to the WWW server 8, and the process is terminated.

Also in this case, instead of transferring only the header portion, the data amount may be further reduced by not transferring the packet itself.

FIG. 18 is a flowchart showing the processing of the relay server when the data is transferred at a reduced resolution.

In step SM1, data to be thinned out is extracted from the packet received from the main server, and the flow advances to step SM2. The target data is, for example, control data such as volume, pitch bend, and after touch. When the packet does not include the target data, the received packet is transferred to the WWW server 8 as it is.

At step SM2, the data is converted into a value corresponding to the designated resolution. For example, when reducing the resolution to 1/4, all the target data of the same type in the packet are set to 1
/ 4 times, and converted to a value obtained by truncating the decimal part.

At step SM3, only one data having the same conversion value is left in the packet, the other data is deleted, and the packet is transferred to the WWW server.

It is to be noted that the target data is modulo (modul).
o) The operation may be performed so that only the operation result of 0 is left and the others are deleted.

Further, a plurality of target data may be provided so that an individual resolution can be specified for each.

In this embodiment, by using the Internet, performance information (MIDI data), audio data (audio data) and performance video (image data) in a performance hall can be supplied to an unspecified number of users. . The user can obtain MIDI data and image data in real time without going to the performance hall while staying at home.

In each of a plurality of performance venues, if each encoder adds common time information to MIDI data or the like, a session between the plurality of venues becomes possible.

A plurality of relay servers can be provided, and data can be independently reduced according to the number of accesses of each relay server, thereby alleviating line congestion. Increasing the number of relay servers can reduce line congestion without thinning data, but thinning data can reduce line congestion even with a small number of relay servers. .

However, when data is reduced, the sound quality or image quality is reduced. Therefore, the relay server can set a data thinning rate and a thinning method that can be independently allowed, and the number of users who can access the relay server.

The relay server can provide the user with information on the data thinning rate and the thinning method, and display the data on the display of the home computer. For example,
"Now, the sound quality is degraded." Or "Only music information is currently available." The display is preferably displayed when the user accesses. The user can access a desired relay server by referring to the display.

Although the relay server is similar to a mirror server on the Internet, the mirror server differs from the relay server of this embodiment in that a plurality of mirror servers all perform the same operation and supply the same data.

This embodiment is not limited to the Internet. For example, the present invention can be applied to other communication such as digital serial communication of IEEE 1394 standard and communication satellite.

Although the present invention has been described in connection with the preferred embodiments,
The present invention is not limited to these. For example, it will be apparent to those skilled in the art that various modifications, improvements, combinations, and the like can be made.

[0165]

As described above, according to the present invention,
When the number of lines being accessed is large, the received data can be reduced and transmitted, so that line congestion can be reduced.

Further, since the data to be reduced by one communication device is different from the data to be reduced by another communication device, the quality of data transmitted by each communication device is different. The user can obtain data having a desired quality by selecting a communication device to be accessed.

[Brief description of the drawings]

FIG. 1 is a diagram showing a communication network for musical sound information.

FIG. 2 is a diagram illustrating a configuration of hardware of an encoder and a home computer.

FIG. 3 is a diagram showing a method for dealing with a communication error of MIDI data.

FIG. 4 is a diagram showing a format of a communication packet.

FIG. 5 is a flowchart illustrating a transmission process performed by an encoder.

FIG. 6 is a flowchart illustrating an interrupt process performed by an encoder. FIG. 6A is a flowchart showing the transmission process of the recovery key data, and FIG. 6B is a flowchart showing the transmission process of the recovery sound source setting information.

FIG. 7 is a flowchart illustrating a reception process performed by a home computer.

FIG. 8 is a flowchart showing details of event processing shown in step SD6 of FIG. 7;

FIG. 9 is a flowchart showing an interrupt process performed by the home computer.

FIG. 10 is a diagram showing a configuration of a memory in the relay server.

FIG. 11 is a graph showing a relationship between the number of accesses and a thinning coefficient.

FIG. 12 is a flowchart illustrating processing of the relay server performed when a user accesses the relay server.

FIG. 13 is a flowchart illustrating a process performed by the relay server when the user releases access to the relay server.

FIG. 14 is a flowchart illustrating processing of the relay server when the relay server receives data from the main server.

FIG. 15 is a flowchart illustrating processing of the relay server when the relay server thins out recovery data.

FIG. 16 is a flowchart illustrating a process of the relay server when the relay server preferentially transmits a key-off.

FIG. 17 is a flowchart illustrating processing of the relay server when the relay server deletes and transfers image data.

FIG. 18 is a flowchart illustrating a process of the relay server when the relay server transfers data at a reduced resolution.

[Explanation of symbols]

1 performance hall, 2 MIDI instruments, 3,5 encoder, 4 camera, 6 router, 7
Main server, 8 WWW server, 9 home computer, 10 MIDI sound source, 11 audio output device, 12 relay server, 21 RAM,
21a key-on buffer, 21b sound source setting information buffer, 22 ROM, 23 CPU, 24
Timer, 25 external storage device, 26 input device, 27 display device, 28 sound source, 29 Internet interface, 30 MIDI interface, 31 bus, 41 header section, 42 data section, 43 checksum,
44 data ID, 45 sequence number,
46 time information, 47 event data length,
48 MIDI data or image data, 51 current access number, 52 overflow flag, 5
3 Current decimation factor, 54 Permitted number of accesses, 5
5 Allowable decimation factor, 56 Table number, 5
7th candidate relay server address

Claims (27)

[Claims] 1. A receiving means for receiving data, an access number recognizing means for recognizing the number of lines being accessed from outside by itself, and an access by reducing the data received by the receiving means according to the number of lines. A data communication device comprising: a transmission unit that transmits data to a medium line. 2. The data communication apparatus according to claim 1, wherein said transmitting means reduces the data by any one of data separation, data differentiation, data resolution operation, and time resolution operation, or a combination thereof. 3. The data communication device according to claim 1, wherein the data received by said receiving means includes at least MIDI data. 4. A communication system including a plurality of communication devices each having a reception unit and a transmission unit, wherein the reception unit in each of the plurality of communication devices is a unit for receiving the same data, and In the communication device, the transmitting means is a means capable of reducing and transmitting data received by the receiving means, and a communication system in which data to be reduced by one communication device and data to be reduced by another communication device are different. . 5. A communication system including a plurality of communication devices each having a receiving unit, an access number recognizing unit, and a transmitting unit, wherein the receiving unit in each of the plurality of communication devices receives the same data. The number-of-accesses recognizing means is means for recognizing the number of lines that are accessing the own communication device from the outside. In the plurality of communication devices, the transmitting unit receives the signal according to the number of lines. A communication system in which the data to be reduced by one communication device and the data to be reduced by another communication device are different from each other and are means for transmitting the reduced data to the line being accessed. 6. The communication system according to claim 5, wherein an object or a ratio of the data to be reduced by the transmission unit of the one communication device is different from that of the transmission unit of the other communication device. 7. The communication system according to claim 5, wherein the transmission means of the plurality of communication devices can further transmit information on data reduction. 8. The communication apparatus according to claim 1, wherein the communication device accepts a new access when the number of lines being accessed is less than a predetermined number, and accepts another access when the number of lines being accessed is equal to or more than a predetermined number. The communication system according to any one of claims 5 to 7, further comprising a transfer unit for transferring to a communication device. 9. The data received by the receiving unit of each communication device includes at least MIDI data.
The communication system according to any one of the above. 10. A step of receiving data; b) a step of recognizing the number of lines that are accessing itself from outside; and c) a step of reducing the received data according to the number of lines and performing access. Transmitting the data to the line. 11. The data communication method according to claim 10, wherein in the step c), the data is reduced by any of data separation, data differentiation, data resolution operation, time resolution operation, or a combination thereof. . 12. The method according to claim 1, wherein said step a) comprises at least MIDI.
The data communication method according to claim 10 or 11, wherein data including data is received. 13. a) a plurality of communication devices receiving the same data; and b) one of the plurality of communication devices and another of the communication devices transmitting different data from the received data. Transmitting the reduced data. 14. a) a plurality of communication devices receiving the same data; b) a step of recognizing the number of lines each of which is accessing itself from outside; c) the plurality of communication devices receiving the same data. Is a step of reducing the received data according to the number of lines and transmitting the reduced data to the line being accessed, wherein one of the plurality of communication devices and the other Transmitting different data from among the received data. 15. The data communication method according to claim 14, wherein in the step c), an object or a ratio of data to be reduced by one communication device is different from that of another communication device. 16. The data communication method according to claim 14, wherein the step c) further transmits information on data reduction. 17. d) The plurality of communication devices,
15. The method according to claim 14, further comprising: accepting a new access when the number of lines being accessed is less than a predetermined number, and transferring the new access to another communication device when the number of lines being accessed is equal to or more than a predetermined number. 17. The data communication method according to any one of items 16 to 16. 18. The method according to claim 18, wherein said step a) comprises at least MIDI
The data communication method according to claim 14, wherein data including data is received. 19. A procedure for receiving data, b) a procedure for recognizing the number of lines being accessed from outside by itself, and c) an access while reducing the received data according to the number of lines. Recording a program for causing a computer to execute a procedure of transmitting to a line. 20. The program according to claim 19, wherein said step c) reduces the data by any one of data separation, data differentiation, data resolution operation, time resolution operation, or a combination thereof. Medium. 21. The method according to claim 19, wherein said step a) comprises at least MIDI
21. A medium recording the program according to claim 19, wherein the medium receives data including data. 22. a) a procedure in which a plurality of communication devices receive the same data; and b) a process in which one of the plurality of communication devices and another of the plurality of communication devices transmit different data from the received data. A medium on which a program for causing a computer to execute the procedure of reducing and transmitting is recorded. 23. a) a step in which a plurality of communication apparatuses receive the same data; b) a step of recognizing the number of lines each of which is accessing itself from outside; c) the plurality of communication apparatuses; Is a procedure in which each of the communication devices reduces the received data according to the number of lines and transmits the reduced data to the line being accessed, and the communication device performs communication between one communication device and another communication device among the plurality of communication devices. A medium for recording a program for causing a computer to execute a procedure of reducing and transmitting different data from received data. 24. The medium according to claim 23, wherein in the step c), an object or a ratio of data to be reduced by one communication device is different from that of another communication device. 25. The medium according to claim 23, wherein said step c) further transmits information on data reduction. 26. Further, d) the plurality of communication devices are:
24. The method according to claim 23, further comprising a step of accepting a new access when the number of lines being accessed is smaller than a predetermined number, and transferring the new access to another communication device when the number of lines being accessed is equal to or more than a predetermined number. 26. A medium on which the program according to any one of items 25 to 25 is recorded. 27. The method according to claim 27, wherein said step a) comprises at least MIDI
A medium recording the program according to any one of claims 23 to 26, which receives data including data.