JPH02226889A - Moving picture conference communication system - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention relates to integrated service digital networks (hereinafter referred to as rIS).
The present invention relates to a video conference communication system for holding a conference using video communication between a plurality of users through a communication network such as a "DN communication network".

With the recent development of communication technology, it has become possible to hold meetings using video communication. However, if each user established a communication path to a central video conference device, a special video conference device would be required within the communication network.
Furthermore, as the number of users participating in a conference increases, the size of the conference device increases rapidly. Therefore, by connecting each user's terminal in a chain using a communication network such as 1SDN and configuring one loop-shaped communication channel, it is possible to connect a large number of users without using special video conferencing equipment. A method of video conference communication is being considered.

[Conventional technology]

As such a video conference communication system, for example, as shown in FIG. 4, each terminal 51 is connected in a chain with two communication channels 52 and 53, an uplink and a downlink, and the entire communication is in a loop. The video signal of the main speaker (terminal A) during the conference is transmitted to one channel 52.
and on the other channel 53, all participants (terminals A, , B.

There was one that transmitted audio signals of C...).

[Problem to be solved by the invention]

However, with the method shown in Figure 4, no video information of participants other than the main speaker (B, C, etc.) is transmitted, making it difficult to get the sense of being in a conference with a large number of people. There are no drawbacks. In addition, in order to simply transmit audio information, which generally has a much smaller amount of information than video information,
Since the communication channel 53 that can send the same amount of information as the moving image is used, it cannot be said that the communication channel 53 is necessarily used efficiently.

This invention eliminates such conventional drawbacks and
It is an object of the present invention to provide a video conference communication system that can perform video conference communication with a sense of realism by efficiently using a communication network such as a communication network.

[Means to solve the problem]

In order to achieve the above object, the video conference communication system of the present invention connects a plurality of terminals l in a chain through a pair of communication channels 2.3, as shown in FIGS. 1 and 2. , constitutes a loop-shaped communication channel as a whole,
Transmitting video information of a specific terminal 1i through one communication channel 2 of the pair of communication channels 2 and 3,
In the other communication channel 3 of the above-mentioned pair of communication channels 2 and 3, each terminal l other than the above-mentioned specific terminal 1i
The video information of each terminal 1 other than the specific terminal 1i is transmitted in the assigned time slot 4, and the video information of each terminal 1 other than the specific terminal 1i is transmitted in the allocated time slot 4, and the video information of each terminal 1 other than the above specific terminal 1i is transmitted in the free time slot of the other communication channel 3. 41, it is characterized by transmitting audio information.

[Effect]

On one communication channel 2, moving image information of the main speaker during the conference is transmitted.

On the other communication channel 3, video information of each participant other than the main speaker is transmitted in the time slot 4 assigned to each participant. Then, audio information is transmitted in the vacant time slot 4i of the communication channel 3. Therefore, although there are fewer informants compared to the video information of the main speaker, video information of each of the other participants is transmitted.

〔Example〕

Examples will be described with reference to the drawings.

FIG. 3 is a block diagram showing the circuit configuration of one terminal 1 according to an embodiment of the present invention. For time slots, see FIG. 1. In the figure, 2 is an upstream communication channel, through which encoded video information from the terminal of the main speaker during the conference is transmitted. 3 is the downlink communication channel, and as shown in Figure 1, time slot 4 is allocated to each terminal other than the terminal of the main speaker, and the encoded communication channel of each terminal Video information is transmitted. Furthermore, since the time slot 41 for the main speaker's terminal becomes empty, the encoded audio information of all the terminals is transmitted in the empty time slot 41. Note that this upstream and downstream communication channel 2.3 is, for example, l.
A pair of B channels of the 5DN communication network are used.

1i and 12 are C0DEC013 for the first and second images
and 14 are a first selector that selects the image signal output light from the camera 15 and a synthesizer that synthesizes the image signal input to the display unit 16. The output from the selector 13 is output from each encoder l in the images C0DEC1i and 12.
The outputs from the decoders 1ib and 12b are input to the combiner 14. Further, a second selector 17 is inserted and connected to the upstream communication channel 2, and the output end of the encoder lla of the first image CODEC is connected thereto.

Therefore, when this terminal l is the main speaker, both the first and second selectors 13.17 are set to the first image C0.
Connect to the encoder IXa side of the DEC, and connect the camera 15
The moving image signal from the mobile station is encoded and transmitted to the upstream communication channel 2. In addition, regardless of whether the own terminal l is the main speaker or not, the moving image signal on the uplink communication channel 2 is decoded by the decoder llb of the first image C0DEC and sent via the synthesizer 14. The image is displayed on the display unit 16.

A multiplexer 20 is connected to the downstream communication channel 3, and an encoder 12a of the second image C0DEC is connected to the downstream communication channel 3.
The output terminal of is connected to the multiplexer 20. When the own terminal l is not the main speaker, the video signal from the camera 15 passes through the first selector 13, is encoded by the encoder 12a of the second video C0DEC, and is sent to the multiplexer 20 for downstream communication. Transmitted on channel 3. At this time, the second selector 17 switches to the side that transmits the moving image signal on the uplink transmission channel 2 as is.

As mentioned above, in the downlink communication channel 3, each terminal l is assigned a time slot (4 in FIG. 1), and the multiplexer 20 is configured to , is operative to transfer encoded video signals.

The output terminal of the demultiplexer 21 branch-connected to the downstream communication channel 3 is connected to the decoder 1 of the second image C0DEC.
It is connected to the input end of 2b.

Therefore, the video information transmitted from each terminal via the downlink communication channel 3 is transferred to the demultiplexer 21.
is selected by the decoder 12b, decoded by the decoder 12b, and the combiner 14
The video image is combined with the moving image of the main speaker and displayed on the display unit 16.

The amount of video information from each terminal is only the amount of information corresponding to the time slot allocated to each terminal. Therefore, for example, if the video information of the main speaker via uplink communication channel 2 is 30 frames/second and the number of participants in the conference is 60 (60 terminals), the video information of those other than the main speaker is One frame is generated every two seconds, and a so-called decomposed photograph-like moving image is displayed on the display unit 16.

22 is an audio PCM-C0DEC (hereinafter "audio C0D
EC22J), the audio signal from the terminal operator's microphone 23 is input to the encoder 22a, and the encoded audio information is sent to the multiplexer 20 described above.
is input. Then, voice information is input into an empty time slot, that is, a time slot (4t in FIG. 1) assigned to the main speaker. Therefore, audio information is transmitted from all terminals in one time slot.

Further, the output from the demultiplexer 21, that is, the encoded audio information on the downlink communication channel 3 is input to the decoder 22b of the audio C0DEC, where it is decoded and output to the speaker 24. Therefore, audio information from all terminals is simultaneously played from this speaker 24.

An echo canceller 25 is branch-connected to the output line of the microphone 23, and the output end of the echo canceller 25 is connected to the input end of a subtracter 26 which is interposed and connected to the output end of the decoder 22b. Therefore, only the user's own voice signal is canceled by the subtracter 26, and the user's own voice is not output from the speaker 24. In addition, in order to send the input audio signal transmitted through the downlink communication channel 3 to another terminal via the downlink communication channel 3, the audio signal inputted to the speaker 24 is branched and the audio signal input to the microphone 23 is branched. The signal is inputted to an adder 27 inserted and connected to the output line of the audio C0DEC, encoded by the audio CODEC encoder 22a, and returned to the downstream communication channel 3 from the multiplexer 20.

In addition, the right to transmit moving images via uplink communication channel 2 can be transferred to the l
This can be done by navigating between each terminal through packet communication using the D channel (not shown) of the 5DN communication network. The operations of each selector 13, 17, multiplexer 20, and demultiplexer 2L described above are controlled according to this transmission right.

In the above embodiment, the pair of communication channels 2.3 are channels in opposite directions, upstream and downstream, but the pair of communication channels may transmit information in the same direction.

〔Effect of the invention〕

According to the video conference communication system of the present invention, one communication channel is allocated to video information of the main speaker in a conference to convey detailed information on facial expressions and movements, and video information of other participants is transmitted. is another communication channel that was conventionally used only for transmitting audio information, and can convey general movement information along with audio. Therefore, for example, in a basic 15DN network using 2B+D channels, it is possible to efficiently utilize two communication channels to perform realistic conference communications without providing a special conference device on the network side.

[Brief explanation of the drawing]

Figure 3 is a diagram of the principle of the present invention. FIG. 2 is a configuration diagram of the present invention, FIG. 3 is a configuration diagram of one terminal of the embodiment, FIG. 4 is a configuration diagram of a conventional example. In the figure, 1...terminal, 1i...Specific terminal, 2...communication channel, 3... Communication channel, 4...Time slot, 4 yuan...Empty time slot. /r′”−°゛... Principle diagram of the present invention Figure 1

Claims (1)

[Claims] A plurality of terminals (1) are connected in a chain by a pair of communication channels (2, 3) to constitute a loop-shaped communication channel as a whole, 3), one of the communication channels (2) transmits the video information of the specific terminal (1i), and the other communication channel (3) of the above pair of communication channels (2, 3) transmits the video information of the specific terminal (1i). A time slot (4) is allocated to each terminal (1) other than the specific terminal (1i), and each terminal (1) other than the specific terminal (1i) is used in the assigned time slot (4). ), and audio information is transmitted in an empty time slot (4i) of the other communication channel (3).