JPH09270792A - Multi-point video conference system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily provide a multi-point conference equipment by providing a 1st circuit connection means capable of communication of one to one terminal equipments at remote location, a 2nd circuit connection means for 1:N terminal equipment communication, and a transmission path revision means to the conference equipment. SOLUTION: A CODEC connecting to each point in terms of 1 to 1 relation through the use of an ISDN applies multiple address communication of information sent from a connection destination during utterance to other CODEC and sends the information received by multiple address communication to a connection destination so as to manage a multi-point conference. For example, let a point A be a chairman, and points B, C, D be participants, then a CODEC A1 is connected to the point B, a CODEC A2 is connected to the point C, and a CODEC A3 is connected to the point C respectively. When the point A makes utterance, the same video image is sent to the CODECs A1-3 and coded and sent to connection destination stations, the points B-D. Thus, each connecting point views the video image sent from the point A at the same time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multipoint video conference system in which transmission / reception between a terminal group connected to a local area network and a terminal group connected to an ISDN line is controlled.

[0002]

2. Description of the Related Art A multi-point video conference is highly useful because it enables a video conference by connecting a plurality of points rather than a one-to-one conference, and a plurality of video conference systems are connected via a line to transmit signals. A multipoint conference control unit (hereinafter referred to as MCU) that realizes a broadcast communication and a multipoint conference by switching the route has been put on the market. The MCU is
It generally has two modes of operation. The first operation mode is called a conference mode, and when a connected terminal speaks, the MCU selects the speaker's terminal by controlling the terminal in charge of the chair or the volume of the speaker, and the speaker Send images to other participating connected terminals. The other mode is called a broadcast mode, in which a predetermined terminal mainly makes a call, and the other terminal becomes a reception-only unless it is specifically permitted. In the structure of the MCU according to the prior art, a line connecting means for connecting to a plurality of terminals and a received signal are separated into voice, image and data, and the image and data are selected by a switching device and the line connecting means is used. Send to the connected terminal. The voice is usually superposed by the synthesizing means and then transmitted to the terminal connected through the line connecting means. The maximum number of terminals that can be connected depends on the structure of the device,
When connecting more than a predetermined number of devices, the MCUs are regarded as one terminal and the MCUs are connected to each other, and as if a large number of devices are connected. Further, due to the circuit configuration on the way, many switching means and image / voice / data demultiplexing / synthesizing circuits are involved, so that there is a drawback that the delay time of transmission becomes long and a smooth conference cannot proceed. FIG. 4 shows a method for expanding the number of connection points by cascade connection, and FIG. 5 shows a method for expanding the number of connection points by hierarchical connection. In addition, when many devices are to be connected in a single device, it is necessary to have a means for handling the maximum number of connections, which causes the device to be large and expensive.

[0003]

The above-mentioned prior art does not take into consideration the fact that a flexible configuration is possible with respect to an increase / decrease in the number of connected terminals, and as a result, a plurality of MCUs are connected to each other or are assumed. Since it is necessary to secure a device scale commensurate with the maximum number of connected terminals, it takes time to transfer and switch information, which hinders smooth conference proceedings, and makes the device large and expensive. there were.

[0004]

SUMMARY OF THE INVENTION The present invention is to solve these problems, in which video conference terminals capable of transmitting and receiving voice data and image data are arranged at a plurality of points, and a local area network is used. In a multipoint video conference system that controls switching of data that flows between connected video conference terminals, a remote transfer between one-to-one terminals connected to a digital line of a synchronous transfer system having a constant transfer rate. First to enable communication
Second line connecting means, which is connected to the asynchronous transfer type digital line and enables communication between 1 to N (N is 1 or more) terminals, the first line connecting means, and the second line connecting means.
There is provided a multipoint video conference system including a transmission route changing unit capable of changing a transmission route to the line connecting unit.

[0005]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of a multipoint video conference system of the present invention, and FIG. 2 is a block diagram of an encoding / decoding device of the present invention. In FIG. 1, 10 is a multipoint video conference device, 11 to 13 are encoding / decoding devices (codecs), 20 is a video conference system, and the plurality of codecs 11 to 13 are bus-type networks 14.
Connected to each other. In this embodiment, Ethernet which is the industry standard is used, but the type of this network is not limited to this. In FIG. 2, the control unit 30 has a function of controlling the operation states of the codecs 11 to 13, the video I / F 31 of the image input unit is responsible for input / output of the image signal, and the audio I / F 32 of the audio input / output unit is Responsible for input and output of audio signals,
Image encoding / decoding unit H.264 33 of 261 is responsible for compression / expansion of the image signal, the audio encoding / decoding unit 34 is responsible for compression / expansion of the audio signal, and the packetization unit 35 is for packetization for transmitting the encoded information to the bus network. The route changing unit 36 functions to return the received packet to the original encoded information, and the route changing unit 36 has a function of switching the route for transmitting the encoded information according to an instruction from the control unit 30, and 37 of the multiplexing unit H221 performs encoding. Image information, audio information,
It has the function of multiplexing auxiliary data and separating the received multiplexed information into images, audio, auxiliary data, etc.
The I / F 38 is an interface for transmitting and receiving packetized encoded information, and the ISDNI / F 39 is an interface for a public digital line. The plurality of codecs 11 to 13 are connected to an audio / video selector (hereinafter referred to as AVS) 15 and are capable of bidirectionally transmitting video / audio information. The AVS 15 is connected with a plurality of video input devices such as a TV camera 1 for displaying a normal person or video, a document camera 2 for displaying a document image, etc., and a plurality of microphones 3 can be connected. Multiple TV monitors 4 can be connected to send video to each codec.
It is possible to display by selecting or synthesizing audio or video / audio received from each codec. When operating this device, it is possible to connect to a connection destination that does not exceed the number of codecs built in this device. In other words, each of the codecs built in the device is connected to the connection destination one-to-one via the digital line (ISDN). Originally, a multipoint conference system is a device that connects a plurality of bases to hold a conference, and sends the video of the speaker to another base to advance the conference. In this device, a codec that is connected to each site on a one-to-one basis using ISDN broadcasts the information sent from the connection destination that is speaking to another codec and receives the information by the broadcast. Operates multipoint conferences by sending information to the other party. Specifically, it is assumed that the base A is the chairman and the bases B, C, and D are the participants, and that this device is located at the base of the chairman. Further, a codec A1 and a base B built in this apparatus, a codec A2 and a base C, and a codec A3 and a base D (not shown) are connected to each other. Code A when site A is speaking
The same video is sent to 1 to 3, encoded, and transmitted to each connection partner station and bases B to D. Therefore, at each connection site, the images sent from site A can be viewed at the same time. When the base B speaks, the video of the base B is encoded by the codec B and sent to the codec A1 of the base A connected one-to-one. The coded information received by the codec A1 is sent to the codecs A2 and A3 of the other site A via the bus network 14, and the codec A2,
A3 is sent to the codecs of the bases C and D, which are connected one-to-one. If you send it to the site B, you can see the video of yourself, but you may control the flow of the encoded information so that you can see the video of the site A that is the chairman. A method of controlling the flow of information will be described. The coded information is sent to the bus type network as packets. Address information that uniquely indicates the recipient and the sender is added to the beginning of the packet. As the destination address information, individual address information or address information of a plurality of groups, all devices connected to this network It is possible to describe address information indicating This network (LAN) can also be connected to a remote network by connecting a router that realizes a wide area network (WAN) connection. The control information of the signal flow in each codec is transmitted from the master codec to each slave codec via the bus type network.
In FIG. 1, the master is A1 and the slaves are A2 to An. The master codec has a function of communicating with an AVS that controls the input / output of images / voices and determining the overall operating characteristics of the multipoint conference apparatus.

[0006]

INDUSTRIAL APPLICABILITY As described above, according to the present invention, an ordinary video conference system that can be produced at a low cost is used as a local area network (LA
A multipoint conference device can be easily configured by connecting via N). Further, since the control of each codec and the information to be transmitted are mutually transmitted via the LAN, each codec does not need to be in the same place, and may be in a remote place connected to a wide area network (WAN). Therefore, it is possible to easily realize a multipoint conference even on a network where ISDN, LAN, and WAN are mixed, which was difficult in the past.
There is an effect that it brings great benefits to users.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a connection state of a multipoint video conference system according to the present invention.

FIG. 2 is a block diagram of an encoding / decoding device according to the present invention.

FIG. 3 is a diagram illustrating a connection state of a conventional multipoint video conference system.

FIG. 4 is a diagram illustrating a cascade connection of a conventional multipoint video conference connection device.

FIG. 5 is a diagram illustrating a connection state of a conventional multipoint video conference system.

[Explanation of symbols]

 10 multipoint video conference device 11, 12, 13 codec 14 ISDN network 31 video I / F 32 audio I / F 33 H.264 261

Claims (1)

[Claims] 1. A video conference terminal capable of transmitting and receiving voice data and image data is arranged at a plurality of points, and
In a multipoint video conference system that controls switching of data that flows between video conference terminals connected by a local area network, a multi-point video conference system is connected to a digital line of a synchronous transfer system having a constant transfer rate.
A first line connecting means for enabling communication between remote terminals between one-to-one terminals and a digital line of an asynchronous transfer system for communication between one-to-N terminals (where N is 1 or more). Multi-point video conferencing system, characterized in that the multi-point video conferencing system is comprised of a line connection means, and a transfer path changing means capable of changing a transfer path between the first line connecting means and the second line connecting means. .