JPH10313453A - Multiple site video conference connecting method with different speeds and system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simply construct intercommunications with different speeds and to suppress costs increase by decoding video from each terminal that has a different transfer rate, thinning it, synthesizing it, after that, encoding it with each transfer rate and sending it to each terminal. SOLUTION: An image signal that is inputted to a multiple site controller 1 through plural transmission paths 12a and 12b is inputted to a speed detector 2 and each transfer rate is detected. Decoders 3a and 3b decode each image based on transfer rate information from the detector 2 and an output is inputted to an image synthesizer 4. The synthesizer 4 thins moving images in a CIF format which is separately decoded, converts them into a predetermined size, synthesizes them through an enable signal which is inputted from a timing generator 5 to be one image and separately supplies them to encoders 6a and 6b. The encoders 6a and 6b encode them in their own speeds based on a transfer rate signal from the detector 2 and send them to each terminal through transmission paths 61a and 61b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-point video conference system using multi-screen multiplexing, and more particularly to a method for providing a multi-point conference between terminals of different speeds provided with a plurality of encoders.

[0002]

2. Description of the Related Art As a prior art of a video conference system, the following known documents are referred to.

(1) JP-A-7-95553 discloses that
There has been proposed an electronic conference device capable of improving image quality without increasing the transfer rate and the number of channels.

(2) JP-A-6-70040 discloses that
In a multipoint video conference system, a multipoint simultaneous display function is provided, and the number of screen divisions can be changed without a predetermined number according to the number of display points, thereby preventing the presence of a non-display part without impairing the realism in the screen display. There is proposed a configuration of a multi-point video conference system that does not cause a problem.

[0005] (3) Japanese Patent Application Laid-Open No. 4-160884 discloses that a digital communication line is connected to n home line termination units (DSU) and n communication network control units (NCU), and digital signals of image information at n points are transmitted. The signal is input to a video signal encoding / decoding device (CODEC) while being switched by a selector, and the analog video signal output is sequentially synthesized and displayed on one monitor television by a multiplex image synthesizing device having an image storing and synthesizing function, and further synthesized A multi-source video conference system has been proposed which realizes an (n + 1) -source video conference by converting the obtained image into digital data by CODEC and distributing the digital data to each NCU.

In a multipoint video conference system, a plurality of persons use a multipoint control device (MC) at conference terminals at a plurality of points.
U: Multipoint Control Unit (U: Multipoint Control Unit) is used to make a telephone conversation in the form of a conference.

Conventionally, in this type of multipoint video conference system for synthesizing screens at different speeds, a multipoint control device converts a digital video signal transmitted from each conference terminal into an analog signal once to synthesize an image. From, COD again
It was digitized by EC and transmitted to each terminal.

Further, it is necessary to set in advance which terminal (conference terminal) is communicating at what speed.

[0009]

The above-mentioned conventional method has the following problems.

(1) The first problem is that the scale of the hardware increases and the cost increases.

[0011] The reason is that a circuit for returning the video from each terminal to an analog signal once and synthesizing it to a digital signal again is required for the number of terminals.

(2) The second problem is that the transfer rate of each terminal must be set every time a conference is held, which requires a lot of work and is complicated.

The reason is that if the transfer rate is different, the speed of encoding and decoding must be changed.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in view of the above-mentioned problems of the prior art, and has as its object to simplify intercommunication between different speeds in a multipoint video conference using multi-screen composition. It is an object of the present invention to provide a method and a system for connecting a multipoint video conference between different speeds, which suppress the increase in cost by the configuration.

It is another object of the present invention to provide a method and system for connecting a multipoint video conference between different speeds, which eliminates the need to set the transfer rate of each terminal.

[0016]

In order to achieve the above object, the present invention relates to a multipoint video conference system using a multiscreen composition function, wherein a multipoint control unit (MCU) includes:
Video from each terminal having a different transfer rate is decoded, decimated and synthesized, and then encoded at a plurality of encoders at each transfer rate and transmitted to each terminal.

Further, the present invention is characterized in that the transfer rate of a received video is automatically detected to perform decoding and encoding.

[0018]

Next, an embodiment of the present invention will be described with reference to the drawings. In a preferred embodiment of the multipoint video conference system according to the present invention, the multipoint control unit (MCU) includes means for determining a transfer rate of a video received from each terminal, and a method for converting a received video at the determined transfer rate. Means for decoding, means for thinning out the decoded video according to the number of synthesized screens, means for synthesizing each of the thinned images, and means for decoding the synthesized images at respective transfer rates .

According to the embodiment of the present invention, a multipoint video conference using a composite screen can be held even at a point where the transfer rate is different.

According to the embodiment of the present invention, since the transfer rate is automatically detected, and decoding and encoding are performed at the transfer rate of each terminal, the work of setting the transfer rate of each terminal is unnecessary. And Hereinafter, in order to describe this embodiment in further detail, an embodiment of the present invention will be described with reference to the drawings.

[0021]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention; FIG. 1 is a block diagram showing the overall configuration of a multipoint control unit (MCU) according to one embodiment of the present invention.

Referring to FIG. 1, a multipoint controller (MC)
U) 1 includes a speed detector 2, decoders 3a and 3b, an image synthesizer 4, a timing generator 5, and encoders 6a and 6b connected to a plurality of transmission paths. In the figure, for ease of explanation, 12a, 12b, and 12a are used as transmission paths of signals input to the decoder via the speed detector 2.
Although 61a and 61b are shown as the transmission paths connected to the encoder, it goes without saying that the number of transmission paths is not limited to two in the present invention.

An image signal input to the multipoint control unit (MCU) 1 via the plurality of transmission lines 12a and 12b is input to the speed detector 2, and the speed detector 2 detects each transfer rate. .

The detected transfer rate signal is indicated by a line 23a,
23b to the decoders 3a, 3b respectively,
a and 26b are input to the encoders 6a and 6b, respectively.

The decoders 3a and 3b decode the respective images based on the transfer rate information from the speed detector 2, and outputs the outputs of the decoders 3a and 3b to the image synthesizer 4 via lines 34a and 34b. Is entered.

The image synthesizer 4 thins out each of the inputted moving pictures in the CIF format, converts them into a predetermined size, and inputs them from the timing generator 5 via a line 54. The images are combined by the enable signal to form one screen and supplied to the encoders 6a and 6b via the lines 46a and 46b, respectively.

The encoders 6a and 6b encode at the respective speeds based on the information of the transfer rate signal from the speed detector, and transmit them to the terminals via the transmission lines 61a and 61b.

[0028]

As described above, according to the present invention,
In a multipoint video conference, there is an effect that terminals with different transfer rates are prevented from increasing in cost with a simple configuration, and the work of setting the transfer rate of each terminal is not required.

The reason is that the present invention is configured so that the transfer rate is automatically detected, and decoding and encoding are performed at the transfer rate of each terminal.

[Brief description of the drawings]

FIG. 1 is a diagram showing an overall configuration of an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Multipoint control unit (MCU) 2 Speed detector 3a, 3b Decoder 4 Image synthesizer 5 Timing generator 6a, 6b Encoder

Claims (3)

[Claims] In a multi-point video conference system using a multi-screen synthesizing function, in a multi-point control unit (MCU), images from terminals having different transfer rates are respectively decoded, decimated and synthesized, and then a plurality of images are decoded. A multipoint video conference connection method, wherein the encoding is performed at each transfer rate and transmitted to each terminal. 2. The method according to claim 1, wherein the transfer rate of the received video is automatically detected to perform decoding and encoding.
The multipoint video conference connection method described. 3. A multi-point video conference system using a multi-screen combining function, means for determining a transfer rate of a video received from each terminal, means for decoding a received video at the determined transfer rate, and decoding. Means for thinning out the combined video according to the number of combined screens, means for combining each of the thinned images, and means for decoding the combined image at each transfer rate and transmitting it to each terminal. Multipoint video conference system characterized by the following.