JP2705966B2 - Video conference communication method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Summary] The present invention relates to a video conference communication method for holding a video video conference between a plurality of users via a communication network such as an integrated services digital network (hereinafter referred to as an "ISDN communication network"). In order to efficiently use a telecommunications network such as an ISDN telecommunications network to provide realistic video conferencing communication, multiple terminals are connected in a chain by a pair of communication channels, and a loop is formed as a whole. A communication channel is formed, and one of the pair of communication channels transmits moving image information of a specific terminal, and the other communication channel allocates a time slot to each terminal other than the specific terminal. Allocate the video information of each terminal in the allocated time slot, and transmit the audio information in the vacant time slot of the other communication channel. Sea urchin to configure.

[Industrial applications]

The present invention relates to an integrated services digital network (hereinafter referred to as "ISDN
The present invention relates to a video conference communication method for performing a video communication conference between a plurality of users via a communication network such as a communication network.

2. Description of the Related Art Recent developments in communication technology have made it possible to hold conferences using moving image communication. However, if each user establishes a communication path to the central video conference device, a special video conference device is required in the communication network, and the number of users participating in the conference increases. Then, the scale of the conference device suddenly becomes large.
Therefore, by using a communication network such as ISDN to connect the terminals of each user in a chain and configure a single loop communication channel, a large number of users can be connected without using a special video conference device. A method of performing a video conference communication by using the method has been considered.

[Conventional technology]

As such a video conference communication system, for example,
As shown in the figure, each terminal 51 is connected in a chain by two communication channels 52 and 53 of up and down to form a communication channel in a loop as a whole, and a main speaker (terminal A) during a conference is connected. ) Is transmitted on one channel 52, and on the other channel 53, all participants (terminals A, B, C
…) Was transmitted.

[Problems to be solved by the invention]

However, in the method as shown in FIG. 4, since the moving image information of the participants (B, C...) Other than the main speaker is not transmitted at all, it is not possible to obtain a sense of realism that a conference is being held by a large number of people. There is. Also, in general, a communication channel 53 capable of transmitting the same amount of information as a moving image is used only for transmitting audio information having a significantly smaller amount of information than moving image information. It was not always said that it was being used efficiently.

The present invention solves such conventional drawbacks and provides a moving image conference communication method capable of performing a moving image conference communication with a sense of reality by efficiently using a communication network such as an ISDN communication network. The purpose is to do.

[Means for solving the problem]

In order to achieve the above object, the video conference communication method of the present invention comprises connecting a plurality of terminals 1 in a chain by a pair of communication channels 2 and 3, as shown in FIGS. , Constitute a loop-like communication channel as a whole,
The moving image information of the specific terminal 1i is transmitted on one communication channel 2 of the pair of communication channels 2 and 3, and on the other communication channel 3 of the pair of communication channels 2 and 3, A time slot 4 is allocated to each terminal 1 other than the specific terminal 1i, and the moving image information of each terminal 1 other than the specific terminal 1i is transmitted in the allocated time slot 4, and It is characterized in that voice information is transmitted in a vacant time slot 4i of the communication channel 3.

[Action]

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

In the other communication channel 3, moving image 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 the amount of information is smaller than the moving image information of the main speaker, the moving image information of each of the other participants is transmitted.

〔Example〕

 Embodiments will be described with reference to the drawings.

FIG. 3 is a block diagram showing a circuit configuration of one terminal 1 according to the embodiment of the present invention. FIG. 1 is referred to for the time slot. In the figure, reference numeral 2 denotes an uplink communication channel, and encoded video information is transmitted from a terminal of a main speaker in a conference. Numeral 3 denotes a downlink communication channel, in which a time slot 4 is allocated to each terminal other than the terminal of the main speaker, as shown in FIG. Moving image information is transmitted. Also, a time slot for the terminal of the main speaker
Since 4i becomes empty, encoded voice information of all terminals is transmitted in the empty time slot 4i. As the upstream and downstream communication channels 2 and 3, for example, the B channel of the ISDN communication network is used. A pair is used.

11 and 12 are first and second image for CODEC _o 13 and 14,
A first selector for selecting an output destination of an image signal from the camera 15 and a synthesizer for synthesizing an image signal input to the display unit 16. The output from selector 13 is the image code
Input to each encoder 11a and 12a in C11 and C12,
The outputs from 1b and 12b are input to the synthesizer 14. Also, a second selector 17 is inserted and connected to the upstream communication channel 2,
The output terminal of the encoder 11a of the first image CODEC is connected thereto.

Therefore, when this terminal 1 is the main speaker,
The first and second selectors 13 and 17 are both connected to the encoder 11a of the first image CODEC, and the moving image signal from the camera 15 is encoded and transmitted to the upstream communication channel 2.
Regardless of whether or not own terminal 1 is the main speaker,
The moving image signal on the upstream communication channel 2 is the first image
The image is composited by the CODEC tecoder 11b and displayed on the display unit 16 via the synthesizer 14.

A multiplexer 20 is interposed and connected to the downstream communication channel 3, and an output terminal of the encoder 12 a of the second image CODEC is connected to the multiplexer 20. And
When the own terminal 1 is not the main speaker, the moving image signal from the camera 15 is passed through the first selector 13 to the second moving image signal.
Multiplexer encoded by CODEC encoder 12a
At 20, it is transmitted to the downstream communication channel 3. At this time, the second selector 17 switches to the side that transmits the moving image signal on the upstream transmission channel 2 as it is.

As described above, the time slot (4 in FIG. 1) is allocated to each terminal 1 in the downlink communication channel 3, and the multiplexer 20 controls the time slot allocated to the own terminal 1. , To transfer the encoded video signal.

The output terminal of the demultiplexer 21 branched and connected to the downstream communication channel 3 is connected to the input terminal of the decoder 12b of the second image CODEC. Therefore, the moving picture information transmitted from each terminal through the downstream communication channel 3 is selected by the demultiplexer 21 and is combined by the decoder 12b, and is combined with the moving picture of the main speaker by the combiner 14 to be displayed on the display unit. Appears on 16.

The moving image information from each terminal has only the information amount of the time slot assigned to each terminal. Therefore, for example, if the moving image information of the main speaker on the upstream communication channel 2 is 30 frames / second, and if the number of participants in the conference is 60 (60 terminals), the moving image information other than the main speaker is 2
One frame is formed every second, and a so-called disassembled photographic moving image is displayed on the display unit 16.

Reference numeral 22 denotes a voice PCM-CODEC (hereinafter referred to as "voice CODEC 22"). A voice signal from the microphone 23 of the terminal 1 is input to the encoder 22a, and the coded voice information is transmitted to the multiplexer 20 described above. Is entered. Then, there is a vacant time slot, that is, a time slot assigned to the main speaker (4 in FIG. 1).
Voice information is input to i). Therefore, voice information is transmitted by weighting information from all terminals in one time slot.

The output from the demultiplexer 21, that is, the encoded audio information on the downstream communication channel 3 is input to the decoder 22b of the audio CODEC, where it is decoded and output to the speaker 24. Therefore, audio information from all terminals is simultaneously transmitted from the speaker 24.

An echo canceller 25 is branched and connected to an output line of the microphone 23, and an output terminal from the echo canceller 25 is connected to an input terminal of a subtracter 26 connected to an output terminal of the decoder 22b. Therefore, its subtractor
At 26, only the user's own voice signal is canceled out, and his / her voice does not come out from the speaker 24. Further, in order to transmit the audio signal transmitted and input through the downstream communication channel 3 to another terminal via the downstream communication channel 3 again,
The audio signal input to the speaker 24 is branched, the signal is input to an adder 27 interposed and connected on the output line of the microphone 23, encoded by the encoder 22a of the audio CODEC, and transmitted downstream from the multiplexer 20. Returning to channel 3.

Note that the transfer of the moving image transmission right by the uplink communication channel 2 is performed by the I / O communication channels 2 and 3,
The packet communication using the D channel (not shown) of the SDN communication network can be performed between the terminals in a nagoate manner. Each of the above selectors 13, 17 and multiplexer 20
The operation of the demultiplexer 21 is controlled according to the transmission right.

In the above embodiment, the pair of communication channels 2 and 3 use channels in the reverse direction of uplink and downlink, but the pair of communication channels may transmit information in the same direction.

〔The invention's effect〕

According to the video conference communication method of the present invention, one communication channel is allocated to video information of a main speaker in a conference, and detailed facial expression and motion information is transmitted, and video information of other participants is transmitted. Is another communication channel that has been used only for transmitting voice information in the past, and can transmit rough motion information together with voice. Therefore,
For example, in a basic ISDN network using a 2B + D channel, it is possible to efficiently use two communication channels and perform realistic conference communication without providing a special conference device on the network side.

[Brief description of the drawings]

 FIG. 1 is a block diagram of the principle of the present invention, FIG. 2 is a block diagram of the present invention, FIG. 3 is a block diagram of one terminal of the embodiment, and FIG. 4 is a block diagram of a conventional example. In the figure, 1 ... terminal, 1i ... specific terminal, 2 ... communication channel, 3 ... communication channel, 4 ... time slot, 4i ... vacant time slot.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toshihiro Asami 1015 Uedanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture Inside Fujitsu Limited (72) Inventor Satoshi Okuyama 1015 Kamiodanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture Fujitsu Limited ( 72) Inventor Yoshihisa Mizuno 1015 Uedanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture, Fujitsu Limited (72) Inventor Toshitaka Tsuda 1015, Kamiodanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture Fujitsu Limited (56) References JP1 JP-A-293058 (JP, A) JP-A-62-114391 (JP, A) JP-A-63-115482 (JP, A) JP-A-63-157591 (JP, A) JP-A-1-241959 (JP, A) )

Claims (1)

(57) [Claims] 1. A plurality of terminals (1) are connected in a chain by a pair of communication channels (2, 3) to form a loop-shaped communication channel as a whole. One of the communication channels (2) transmits the moving image information of the specific terminal (1i), and the other communication channel (3) of the pair of communication channels (2, 3) transmits the specific A time slot (4) is allocated to each terminal (1) other than the terminal (1i), and the allocated time slot (4) is used to make a video of each terminal (1) other than the specific terminal (1i). A video conferencing communication method, comprising transmitting image information and transmitting audio information in a vacant time slot (4i) of the other communication channel (3).