JPH09116883A - Video telephone system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To recognize which opposite party is talking among plural call opposite parties by obtaining the physical position of a partial video whose change quantity with a previous frame partial picture in respective video information is the largest on a video display part. SOLUTION: A reception part 72 separately receives video information of plural terminals and receives mixed sound information obtained by mixing sound information of the plural terminals. Sound output means 41 and 42 are arranged near video display means 21 and 22 corresponding to the plural terminals. Position information detection means 142, 143 and 144 obtain change quantity with the previous partial pictures in video information, obtain the physical positions of the partial video whose change quantity is the largest on the video display parts 21 and 22 and execute counting. A sound volume control means 612 sound volume-controls the decoding signals of mixed sound information based on output from the position information detection means so that sound from the sound output means 41 and 42 correspond to the videos from the corresponding video display means and transmits the signals to the sound output means 41 and 42.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an audio output device used mainly as a part of components such as a videophone device and a videoconference device for reproducing a user's voice.

[0002]

2. Description of the Related Art In recent years, with the development of various communication infrastructures and the improvement of image processing technology, video telephone devices have come into practical use. In particular, with the recent improvement in the processing performance of personal computers (hereinafter abbreviated as PCs), there is a noticeable movement of utilizing PCs as videophone constituent parts instead of conventional videophone dedicated devices.

An example of such an example is the Intel ProShare video system 200 announced by Intel Corporation in the United States in 1994. However, the video conference device using such a PC has the following drawbacks.

[0004]

A video conference apparatus using a PC usually assumes a telephone conversation between two or more people. In the case of a call with three or more people, two or more callers are simultaneously displayed on the screen by the function of the multi-window system installed in the PC. In this way, two or more callers are displayed in different windows on the screen so that it is possible to determine who is currently speaking.

Further, by distinguishing the voice quality of the call partner, the user can judge the call partner. However, when actually using the device, the update of the image may be delayed or the quality of the voice may be deteriorated due to the circumstances such as the communication line. Which party is talking during the call? Was sometimes difficult to understand.

[0006]

Means for Solving the Problems The above-mentioned problems correspond to the receiving means for separately receiving the video information of a plurality of terminals and receiving the mixed audio information obtained by mixing the audio information of the plurality of terminals, and the plurality of terminals. A plurality of video display means, a plurality of audio output means corresponding to the plurality of terminals and arranged in the vicinity of the video display means, and a means for obtaining the amount of change from the previous frame partial image in each video information, Position information detecting means for finding and counting the physical position of the largest amount of partial video on the video display part, and the position so that the audio from the audio output means corresponds to the video from the corresponding video display means. Volume control means for controlling the volume of the decoded signal of the mixed voice information based on the output from the information outputting means and sending it to the plurality of voice output means.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

First, the configuration of the videophone device according to the present invention will be described. FIG. 8 is an external view of a general videophone device using a PC. In FIG. 8, 1 is P
C, 2 is a display unit, 3 is a video input unit, 4 is an audio output unit, 5
Is a voice input unit. This figure shows a state in which images of two call partners are displayed side by side on the display unit 2. Hereinafter, description will be made on the premise of such a video arrangement.

Next, FIG. 9 is an internal block diagram of a general videophone device using a PC. In FIG. 9, 1 is P
C, 2 is a video display unit, 3 is a video input unit, 4 is a voice output unit, 5 is a voice input unit, 6 is a video / audio processing unit, and 7 is a communication processing unit. The PC 1 has a CPU 11, a main memory 12, and an HD.
D13 and the video reproducing unit 14. The video / audio processing unit 6 includes an audio reproduction unit 61, a video compression unit 62, and an audio compression unit 63. The communication processing unit 7 includes a transmission unit 71 and a reception unit 72.

Although the video reproducing section 14 is shown as a component of the PC 1 in this figure, it may be a combination of different components. Further, although the audio reproducing unit 61, the video compressing unit 62, and the audio compressing unit 63 exist on the same component,
These may be on separate components. Further, although the video / audio processing unit 6 and the communication processing unit 7 are separate components, they may be integrated on the same component.

Next, a conventional example using the conventional technique will be described with reference to FIG. In FIG. 10, 72 is a receiving unit, 73 is a data distributing unit, 6111 is a voice 1 decoding unit, 6112 is a voice 2 decoding unit, 1411 is a video 1 decoding unit, 1412 is a video 2 decoding unit, and 21 is a video 1 display. Part, 2
Reference numeral 2 is a video 2 display unit, 41 is a left audio output unit, 42 is a right audio output unit, and 612 is a volume control unit. Video 1 display 21
Although the image 2 display unit 22 and the image 2 display unit 22 are described as separate components, this physically shows two areas on a single component.

Next, FIG. 11 is a conceptual diagram of the information flow of the videophone system using the conventional example shown in FIG.
In FIG. 11, 201 is a terminal 1, 202 is a terminal 2, 2
Reference numeral 03 is a terminal 3, and 204 is a host device. Again 341
Is the terminal 1 uplink information sent from the terminal 1 to the host device, 3
42 is terminal 2 upstream information sent from the terminal 2 to the host device, and 343 is terminal 3 downstream information sent from the host device to the terminal 3. Although FIG. 11 describes only the flow of information received by the terminal 3 for simplicity, the information received by the terminals 1 and 2 also flows in the same manner during actual operation.

Next, the operation of this conventional example will be described. As shown in FIG. 11, the terminal 1 sends video information (V (1)) and audio information (A (1)) of the terminal 1 to the host device. Similarly, from terminal 2, video information of terminal 2 (V (2))
And voice information (A (2)) are sent to the host device. The host device receives these pieces of information, and retransmits the information to the terminal that needs each piece of information.

In this example, the video information and audio information of the terminal 1 and the video information and audio information of the terminal 2 are retransmitted as downlink information 343 to the terminal 3. In the terminal 3, the receiving unit 7
The data distribution section 73 distributes the information received in step 2 to the respective information. The distributed information is sent to the corresponding decoding units.

In FIG. 10, the video information of the terminal 1 is sent to the video 1 decoding unit and displayed on the video 1 display unit 21. Similarly, the voice information of the terminal 1 is sent to the voice 1 decoding unit and output via the volume control unit 612. The same applies to the video / audio information of the terminal 2. In this method, the amount of information is increased in order to send all information separately, and high-speed transmission of information is essential. To solve this problem, it is better to mix and transmit a plurality of audio information. This is because in a videophone system, it is rare for two or more parties to speak at the same time.

Next, an embodiment of the present invention utilizing the above principle will be described. FIG. 1 is a configuration diagram of a first embodiment of the present invention. In FIG. 1, reference numeral 72 denotes a receiving unit, and 73
Is a data distribution unit, 611 is an audio decoding unit, 1411 is a video 1 decoding unit, 1412 is a video 2 decoding unit, 21 is a video 1 display unit, 22 is a video 2 display unit, 41 is a left audio output unit, and 42 is a right audio. An output unit, 612 is a volume control unit, and 613 is a left / right balance decoding unit. Video 1 display 21 and video 2 display 2
Although the two have been described as separate components, this physically refers to two regions on a single component.

Next, FIG. 2 is an information flow conceptual diagram of the video telephone system of the present invention shown in FIG. In FIG. 2, 201 is a terminal 1, 202 is a terminal 2, 203 is a terminal 3, and 204 is a host device. 351 is terminal 1 upstream information sent from the terminal 1 to the host device, 352 is terminal 2 upstream information sent from the terminal 2 to the host device, and 353 is terminal 3 downstream information sent from the host device to the terminal 3. Although FIG. 2 describes only the flow of information received by the terminal 3 for simplicity, the information received by the terminals 1 and 2 also flows in the same manner during actual operation.

Next, the operation of the first embodiment will be described. As shown in FIG. 2, the terminal 1 sends video information (V (1)) and audio information (A (1)) of the terminal 1 to the host device. Similarly, from terminal 2, video information of terminal 2 (V (2))
And voice information (A (2)) are sent to the host device.

The host device receives each of these pieces of information and retransmits the information to the terminal that needs each piece of information. In this example, the video information of the terminals 1 and 2, the audio information in which the audio information of the terminals 1 and 2 is mixed, and the left-right balance information of the audio information are retransmitted to the terminal 3 as downlink information 343. In the terminal 3, the information received by the receiving section 72 is distributed to the respective information by the data distributing section 73. The distributed information is sent to the corresponding decoding units.

In FIG. 1, the video information of the terminal 1 is sent to the video 1 decoding unit and displayed on the video 1 display unit 21. The video information of the terminal 2 is sent to the video 2 decoding unit and displayed on the video 2 display unit 22. The audio information mixed is the audio decoding unit 61.
1 to the volume control unit 612. The volume control unit sends output information to the left audio output unit 41 and the right audio output unit 42 based on the signal from the left / right balance decoding unit 613.

With such a configuration, the amount of downlink information to the terminal 3 can be significantly reduced. This is because the left-right balance information is much smaller than the voice information.

Next, another embodiment of the present invention will be described. FIG. 3 is a configuration diagram of the second embodiment of the present invention. In FIG. 3, 72 is a receiving unit, 145 is a data distributing unit, 611 is an audio decoding unit, 1411 is a video 1 decoding unit, and 1 is a video decoding unit.
412 is a video 2 decoding unit, 21 is a left video display unit, 22 is a right video display unit, 41 is a left audio output unit, 42 is a right audio output unit, 142 is a left video counter, 143 is a right video counter, and 144 is a comparison. Reference numeral 612 denotes a volume control unit.

Although the left image display section 21 and the right image display section 22 are described as separate components, they physically show two areas on a single component. Further, the left image display unit 21 and the right image display unit 22 are
Although the rectangle is divided into a plurality of rectangles indicated by “I” or “P”, the rectangle indicated by “I” is an I picture and the rectangle indicated by “P” is a P picture.

The I-picture is a rectangular image information format that represents a simply compressed partial image, and is a compressed image information format that does not include correlation information with the immediately preceding image. P picture is
This is a rectangular image information format that includes correlation information with the partial image that existed immediately before that area. Which rectangular portion of the video has which information format depends on the compression method on the transmission side.

Generally, P pictures have better compression efficiency than I pictures, and the data size can be reduced. The P picture needs to be correlated with the immediately preceding partial image, but cannot be correlated if the partial image changes significantly. Therefore, on the transmission side, in a partial image unit, a greatly changed portion is compressed with an I picture, and a portion that does not change much is compressed with a P picture. The left video counter 142 and the right video counter 143 each have a function of counting the number of I pictures and the number of P pictures of the left and right video display units.

Next, the operation of the second embodiment will be described. The video information decoded by the video decoding unit from the reception unit 72 via the data distribution unit 145 is sent to the left and right video display units. Here, the left counter 142 and the right counter 143 count the number of I pictures in the video display unit. The result of the count is obtained as a ratio of a large change in the left and right images. The count results are compared by the comparison unit 144, and the volume of the left and right audio output units is controlled via the volume control unit 612. In FIG. 3, the left image display unit 21
Since the number of I-pictures is larger in this case, the volume of the left audio output unit 41 is controlled to be higher than that of the right audio output unit 42.

The principle of the present method is that the caller who is mainly speaking often moves his face or mouth or makes a gesture, so by detecting the amount of image change, the right and left of an appropriate volume can be detected. The point is that balance can be obtained. Most of the current image compression techniques have a video compression information format corresponding to the above-mentioned I picture and P picture. Generally, complicated processing is required to detect the image change amount, but when using these video compression techniques, the ratio of the image change amount can be easily obtained by only having a simple counter. .

The second embodiment has the following features as compared with the first embodiment. Since it is not necessary to transmit the left-right balance information, the data transmission amount can be reduced.
Further, it can be applied to a videophone system by ring connection without using a host device. This point will be described next.

FIG. 4 is a block diagram of a videophone system using a host device when the second embodiment is used.
In FIG. 4, 201 is a terminal 1, 202 is a terminal 2, 20
3 is a terminal 3, and 204 is a host device. Further, 311 is terminal 1 upstream information sent from the terminal 1 to the host device, 31
2 is the terminal 2 upstream information sent from the terminal 2 to the host device,
313 is terminal 3 upstream information sent from the terminal 3 to the host device, 301 is terminal 1 downstream information sent from the host device to the terminal 1, 302 is terminal 2 downstream information sent from the host device to the terminal 2, 303 is from the host device It is the terminal 3 downlink information sent to the terminal 3.

Each upstream information includes audio information and video information of each own terminal. Further, each downlink information includes video information of each of the callee terminals and mixed audio information of all the callee terminals. Since the audio left / right balance information is not transmitted,
The amount of data transmission is reduced compared to the past. It is also possible to have a configuration in which a signal obtained by mixing video signals from a plurality of terminals is received and the plurality of received video signals are separated.

Next, FIG. 5 is a block diagram of a ring connection videophone system that does not use a host device when the second embodiment is also used. In FIG. 5, 201 is a terminal 1, 202 is a terminal 2, and 203 is a terminal 3. Also 32
1 is mixed voice information transmitted from the terminal 1 to the terminal 3 322
Is mixed audio information sent from the terminal 2 to the terminal 1, 323 is mixed audio information sent from the terminal 3 to the terminal 2, 331 is video information sent from the terminal 3 to the terminal 1, and 332 is sent from the terminal 1 to the terminal 2. Video information 333 is video information sent from the terminal 2 to the terminal 3.

Such a ring-connected video telephone system has the advantages that no host device is required and that the line cost can be suppressed. When such a ring connection is performed, audio mixing processing by the host device cannot be performed. Therefore, it is necessary for each terminal to independently perform processing such as left-right balance of reproduced sound. In such a case, the method described in the second embodiment is particularly effective.

Another advantage of the second embodiment is that the left-right balance processing of voice can be performed only by changing the receiving side without changing the transmitting side.
In the method of generating the left-right balance information on the transmitting side or the host device, it is necessary to handle the left-right balance information as transmission information of the videophone system.

In such a system, it is necessary to prevent the host device from transmitting the left-right balance information to the device that cannot process the information. In the device of the second embodiment, since such a problem does not occur,
It can be operated as a system that automatically adjusts the left-right volume balance by simply replacing the receiving device.

Next, still another embodiment of the present invention will be described. FIG. 6 is a configuration diagram of the third embodiment of the present invention. In FIG. 6, 72 is a receiving unit, 611 is an audio decoding unit, 141 is an image decoding unit, 2 is an image display unit, 21 is a left image, 22 is a right image, 41 is a left audio output unit, and 42 is a right audio. An output unit, 142 is a left video counter, 143 is a right video counter, 144 is a comparison unit, and 612 is a volume control unit.

In this embodiment, the left image 21 and the right image 22 are
Exists as the left and right halves of an image. Therefore, only one video decoding unit 141 exists, unlike the above-described embodiments.

Next, the operation of the third embodiment will be described. The data input from the receiving unit 72 is the video decoding unit 14
It is decoded at 1 and sent to the video display unit 2. Here, the left counter 142 and the right counter 143 respectively count the number of I pictures in the left half and right half of the video display unit. The result of the count is obtained as a ratio of a large change in the left and right images. The count results are compared by the comparison unit 144, and the volume of the left and right audio output units is controlled via the volume control unit 612. In FIG. 6, since the left video display unit 21 has a larger number of I pictures, the volume of the left audio output unit 41 is controlled to be higher than that of the right audio output unit 42.

Next, another embodiment of the present invention will be described. FIG. 7 is a configuration diagram of the fourth embodiment of the present invention. In FIG. 7, 72 is a receiving unit, 145 is a data distributing unit, 611 is an audio decoding unit, 1411 is a video 1 decoding unit, 1412 is a video 2 decoding unit, 21 is a left video display unit, 2
2 is a right video display unit, 41 is a left audio output unit, 42 is a right audio output unit, 146 is a left extraction unit, 147 is a right extraction unit, 144
Is a comparison unit, and 612 is a volume control unit.

The left extraction unit 146 has a function of extracting a partial video in the central portion of the left video display unit 21 and counting the number of I pictures. Similarly, the right extraction unit 147 has a function of extracting a partial video in the central portion of the right video display unit 22 and counting the number of I pictures.

Next, the operation of the fourth embodiment will be described. The data input from the reception unit 72 is distributed by the data distribution unit 145 according to the purpose, and the video decoding units 1411 and 1
The data is decoded at 412 and sent to the video display units 21 and 22. The left extracting unit 146 and the right extracting unit 147 extract the partial video in the central portion and count the number of I pictures included in the partial video. The count results are compared by the comparison unit 144, and the volume of the left and right audio output units is controlled via the volume control unit 612.

In FIG. 7, since the result of the left extraction unit 146 has more I pictures than the right extraction unit 147, the volume of the left audio output unit 41 is controlled to be higher than that of the right audio output unit 42. . This method is characterized in that the amount of data processing is reduced because the comparison of counts is simplified. In addition, by performing the detection process only on the central part of the image, it is possible to perform the process that is not affected by the movement of the background, and because the central part of the image has the mouth of the other party, the speaker is specified. Appropriate processing is possible.

Further, in this example, the method of simply comparing the central portion is shown, but it may be detected that only the image of the central portion is largely changed. This allows volume balance control to be performed for situations where the image changes only in the central part of conversation or body movement, etc. without reflecting it in the volume balance control when the other party shakes a lot. Is possible.

Further, in the above-mentioned embodiment, the method of adjusting the volume balance directly from the image information is shown, but this is not only the method of directly controlling but also the method of, for example, integrating or averaging a certain past time. But good. By performing such calculation, it is possible to prevent unnaturally sudden volume adjustment.

The means for realizing the present invention need not be hardware as described in the embodiments,
Some or all may be realized by software.

Further, although the description is given on the assumption that the number of windows is two, the number of windows is not necessarily two and three or more windows may be displayed.

As described above, the windows for displaying two or more callers are arranged in the horizontal direction, and the receiving device determines which window the caller who is speaking is displayed, and the windows are displayed on the left and right sides of the display device. By adjusting the left-right balance of the provided speakers, it is possible to control from which direction on the screen the sound is heard and to make it easy for the user to intuitively understand who is speaking.

Further, in the above-described embodiment, the attribute of the video information is the rectangular image information including the correlation information between the I picture which is the rectangular image information format that does not include the correlation information with other images and the immediately preceding image. The description has been made on the assumption that there are two types of attribute information of the P picture, which is the format, but the attribute information does not necessarily have to be two types, for example, in the rectangular image information format that does not include correlation information with other images. There are three types of attribute information: a P picture, which is a rectangular image information format that includes correlation information between an I picture and the immediately preceding image, and a B picture, which is a rectangular image information format that includes correlation information between the immediately preceding image and the immediately following image. You may.

[0048]

As described above, according to the present invention, the left and right sound volume balance for assisting the identification of the speaker can be achieved without increasing the data transmission amount by simply performing a simple expansion on the receiving side device. It can be adjusted automatically. With this function, the caller can more intuitively determine from which caller the caller is speaking, and it is possible to eliminate discomfort when using the videophone system. Further, it becomes possible to apply the function to a ring-connected video telephone system in which a host device is not installed.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a first embodiment of the present invention.

FIG. 2 is a data flow conceptual diagram of an application system example of the first embodiment of the present invention.

FIG. 3 is a configuration diagram of a second embodiment of the present invention.

FIG. 4 is a data flow conceptual diagram (1) of an application system example of the second embodiment of the present invention.

FIG. 5 is a data flow conceptual diagram (2) of the application system example of the second embodiment of the present invention.

FIG. 6 is a configuration diagram of a third embodiment of the present invention.

FIG. 7 is a configuration diagram of a fourth embodiment of the present invention.

FIG. 8 is an external view of an example of an application device of the present invention.

FIG. 9 is an internal configuration diagram of an example of an application device of the present invention.

FIG. 10 is a configuration diagram of a conventional example.

FIG. 11 is a data flow conceptual diagram of an example of a conventional application system.

[Description of symbols] 1 personal computer (PC) 2 video display unit 3 video input unit 4 audio output unit 5 audio input unit 6 video / audio processing unit 7 communication processing unit 11 CPU 14 video playback unit 21 left video display Part 22 Right video display part 41 Left audio output part 42 Right audio output part 141 Video decoding part 142 Left counter 143 Right counter 144 Comparator 145 Data distribution part 146 Left extraction part 147 Right extraction part 201 Terminal 1 202 Terminal 2 203 Terminal 3 204 host device 301 terminal 1 downstream information 302 terminal 2 downstream information 303 terminal 3 downstream information 311 terminal 1 upstream information 312 terminal 2 upstream information 313 terminal 3 upstream information 321 ring mixed voice information 322 ring mixed voice information 323 ring mixed voice Information 331 Ring-type video information 332 Ring-type video information 333 Video information 341 Terminal 1 upstream information 342 Terminal 2 upstream information 343 Terminal 3 downstream information 351 Terminal 1 upstream information 352 Terminal 2 upstream information 353 Terminal 3 downstream information 611 Audio decoding section 612 Volume control section 613 Left-right balance decoding section 1411 Video 1 Decoding unit 1412 Video 2 decoding unit 6111 Audio 1 decoding unit 6112 Audio 2 decoding unit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshio Tanaka 810 Shimoimaizumi, Ebina City, Kanagawa, Ltd.Hitachi Ltd. Office Systems Division (72) Inventor Takashi Yoshitomi 810 Shimoimaizumi, Ebina, Kanagawa Prefecture Hitachi, Ltd. Factory Office Systems Division

Claims (12)

[Claims] 1. Receiving means for receiving video information of a plurality of terminals, receiving mixed audio information obtained by mixing audio information of the plurality of terminals, and further receiving balance information of the audio information, and receiving by the receiving means. Distribution means for distributing various kinds of information to corresponding decoding means, a plurality of video display means corresponding to the plurality of terminals, and a plurality of audio output means corresponding to the plurality of terminals and arranged in the vicinity of the video display means. When,
Based on the decoded signal of the balance information, so that the audio from the audio decoding means for decoding the mixed audio information and the audio from the audio output means correspond to the video from the corresponding video display means,
And a volume control unit for controlling the volume of the output from the voice decoding unit and transmitting the volume to the plurality of voice output units. 2. Receiving means for separately receiving video information of a plurality of terminals and receiving mixed audio information obtained by mixing audio information of the plurality of terminals, a plurality of video display means corresponding to the plurality of terminals, A plurality of audio output means corresponding to a plurality of terminals and arranged in the vicinity of the video display means; a means for obtaining a change amount between the preceding frame partial images in the respective video information; Based on the output from the position information output means, so that the sound from the position information detection means for obtaining the physical position on the video display portion and the sound from the sound output means corresponds to the video from the corresponding video display means, And a volume control unit for controlling the volume of the decoded signal of the mixed voice information and sending the volume to the plurality of voice output units. 3. The means for obtaining the change amount of a partial image according to claim 2, wherein the information format of the compressed image does not include the correlation information with the immediately preceding image and the information of the compressed image with the correlation information with the immediately previous image. A videophone terminal device, characterized in that it is means for detecting and obtaining the amount of each attribute information in a video signal having two types of attribute information. 4. The means for obtaining the variation amount of a partial image according to claim 2, wherein the information format of the compressed image does not include the correlation information with the immediately preceding image or the immediately following image, and the correlation information with the immediately preceding image or the immediately following image. A videophone terminal device, which is a means for detecting and obtaining the amount of each attribute information in a video signal having at least two types of attribute information in the information format of a compressed image including. 5. Receiving means for receiving video information of a plurality of terminals and receiving mixed audio information obtained by mixing audio information of the plurality of terminals, a plurality of video display means corresponding to the plurality of terminals, and a plurality of video display means for the plurality of terminals. A plurality of audio output units corresponding to each other and arranged in the vicinity of the video display unit and an information format of a compressed image that does not include correlation information with the immediately preceding image for each partial image or a compressed image that includes correlation information with the immediately preceding image. The means for obtaining the video information having the attribute information of the information format and the ratio of the partial image having the attribute information including the correlation information with the immediately preceding image among the attribute information of all the partial images displaying the video information from each terminal are calculated. Based on the output from the means for obtaining the ratio, the decoded signal of the mixed voice information is volume controlled so that the sound from the means for obtaining and the sound output means corresponds to the image from the corresponding image display means. And a volume control means for sending to the plurality of audio output means. 6. Receiving means for receiving video information of a plurality of terminals and receiving mixed audio information obtained by mixing audio information of the plurality of terminals, a plurality of video display means corresponding to the plurality of terminals, and a plurality of the plurality of terminals. A plurality of audio output units corresponding to each other and arranged in the vicinity of the video display unit and an information format of a compressed image that does not include correlation information with the immediately preceding image for each partial image or a compressed image that includes correlation information with the immediately preceding image. And means for obtaining video information having attribute information of the information format, and correlation information with the immediately preceding image in the central part of all the partial images among the attribute information of all the partial images displaying the video information from each terminal. Based on the output from the means for obtaining the number of partial images so that the sound from the sound output means corresponds to the image from the corresponding image display means. And a volume control means for controlling the volume of the decoded signal of the mixed voice information and sending it to the plurality of voice output means. 7. A means for connecting three or more terminals, a means for distributing a video signal to each terminal, a means for mixing audio signals of each terminal and transmitting the mixed signals to all terminals, and a method for changing the amount of change in each terminal. Position information detecting means for obtaining a physical position of a large partial image on the image display unit for each terminal, volume balance information between the terminals is obtained from the position information, and the balance information is distributed to each terminal. Characteristic videophone host device. 8. A means for receiving video signals of a plurality of terminals separately, a means for receiving a signal obtained by mixing audio signals of a plurality of terminals, and a means for receiving a partial video having the largest change amount on the video display unit of the own terminal. A videophone terminal device, comprising: position information detecting means for obtaining a physical position, means for transmitting the position information to a host device, and means for receiving volume balance information between terminals from the host device. 9. A means for receiving a signal in which video signals of a plurality of terminals are mixed, a means for receiving a signal in which audio signals of a plurality of terminals are mixed, a means for separating a plurality of received video signals, Position information detecting means for obtaining the physical position of the partial image with the largest amount of change on the image display unit,
A videophone terminal device comprising means for transmitting the position information to the host device and means for receiving volume balance information between the terminals from the host device. 10. The information format of a compressed image in which the position information for obtaining the physical position on the video display unit of the partial video with the largest change amount in claim 7, 8 or 9 does not include the correlation information with the immediately preceding image. And a videophone host device or a videophone, which is obtained based on the amount of each attribute information in a video signal having two types of attribute information in the information format of a compressed image including correlation information with the immediately preceding image. Terminal device. 11. A videophone terminal device according to any one of claims 1 to 6, wherein the plurality of audio output means are left and right audio output means. 12. The videophone host device or the videophone terminal device according to claim 7, wherein the volume balance information is left and right volume balance information.