JPS63203079A - Video conference system - Google Patents

Abstract

PURPOSE:To attain picture transmission with high picture quality by utilizing a bit rate of a terminal equipment which is not in use to improve the picture transmission bit rate. CONSTITUTION:When a facsimile equipment 14 is not in use, a line speed control section 1 multiplies a synchronizing signal of e,g., 64Kb/s of the line side to generate a synchronizing signal with a bit rate of 128Kb/s and it is fed to a video CODEC 11. The CODEC 11 encodes and outputs a picture signal from a video conference equipment 12 based on the synchronizing signal and gives it to a multi-medium multiplexer 13 via the control section 1. The multiplexer 13 multiplexes it with the code signal from the other terminal equipment and sends it to a digital line 15. In using the equipment 14, a signal representing the start is fed to the CODEC 11 from the equipment 14, the CODEC 11 multiplexes it into a code signal representing the picture and gives the result to the control section 11. The control section 1 detects a signal representing the start of the equipment, then the synchronizing signal branched into two and having a bit rate of 64Kb/s is fed respectively to the CODEC 11 and the equipment 14.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to a video conference system.

(Prior Art) FIG. 2 is a block diagram showing a conventional video conference system. In the figure, a video codec 11 converts an image signal output from a video conference device 12 into, for example, 64K.
It is encoded based on a synchronization signal with a bit rate of bit/s, and this encoded signal is applied to the multimedia multiplexer @13. On the other hand, the facsimile device 14 applies a code signal to the multimedia multiplexing device 13 based on the synchronization signal of the bit rate, for example. Multimedia multiplexer 1
3 is a video codec 11 and a facsimile machine @14
When inputting each code signal from , these code signals are multiplexed and sent to the digital circuit 115 . Furthermore, the multimedia multiplexing device 13 separates the multiplexed signals transmitted via the digital line 15 and applies respective encoded signals to the video codec 11 and facsimile device 14. When the video codec 11 receives the code signal, it decodes the code signal to form an image signal and applies this image signal to the video conference device 12 .

However, in the above system, the facsimile device 1
4 monopolizes one communication channel of the digital line 15 even though it is not used all the time, so the line is not used effectively.

(Problems to be Solved by the Invention) As described above, in the conventional video conference system, an attached terminal, such as a facsimile machine, monopolizes one communication channel of a digital line even though it is not used all the time. Therefore, there was a problem that the lines were not being used effectively.

Furthermore, when image signals input to and output from a video conference device are encoded and decoded by a video codec, there is a tendency that the higher the bit rate, the higher the quality of the image transmission.

Therefore, the present invention provides, when the attached terminal is not used,
It is an object of the present invention to provide a video conference system that can increase the bit rate of image transmission by utilizing the bit rate for the terminal.

[Structure of the Invention] (Means for Solving the Problems) The present invention provides a video codec for inputting and outputting image signals to and from a video conference device, a terminal attached to the video conference device, and this terminal. When the terminal is not used, the video codec is operated based on a synchronization signal of a preset bit rate and the image signal is digitally communicated, and when the terminal is used, the synchronization signal is divided into two at the bit rate. The present invention is characterized by comprising a control means for operating the video codec and the terminal based on the above, multiplex converting the image signal and the communication signal of the terminal, and performing digital communication.

(Function) According to the present invention, when the terminal is not used, the bit rate of image transmission is higher than when the terminal is used.

(Embodiments) Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a block diagram showing an embodiment of a video conference system according to the present invention. . In this figure, parts that perform the same functions as the system shown in FIG. 2 are given the same reference numerals for convenience of explanation.

In this embodiment, a line speed control section 1 is inserted between the video codec 11 and facsimile device 14 and the multimedia multiplexing device 13 in the system shown in FIG.

First, when the facsimile device 14 is not used, the line speed control unit 1 multiplies a synchronizing signal of, for example, 64 Kbit/s on the line side to form a synchronizing signal with a bit rate of 128 Kbit/s, and converts the formed synchronizing signal into a video signal. Add to codec 11. When the video codec 11 inputs the synchronization signal of this bit rate, it starts the TV conference based on this synchronization signal. The image signal input from the II device 12 is encoded at the bit rate and output. This code signal is then applied to the multimedia multiplexer 13 via the line speed controller 1. When the multimedia multiplexing device 13 receives this code signal, it multiplexes the code signal with a code signal input from another terminal (not shown) and sends it to the digital line 15.

On the other hand, the multimedia multiplexing device 13 uses digital time 1!
The multiplexed signal transmitted via the video codec 1 is separated via the line speed control unit 1.
1 and a code signal with a bit rate of 128 Kbit/s. When the video codec 11 receives this code signal, it decodes this code signal to form an image signal,
This image signal is applied to the video conference device 12. When the video conference device 12 receives this image signal, it displays an image based on this image signal.

Next, when using the facsimile device 14, a signal indicating activation is sent from the facsimile device 14 to the video codec 1.
Added to 1. When the video codec 11 receives this signal, it multiplexes this signal into a code signal indicating an image and sends it to the line speed control section 1. When the line speed control unit 1 receives this code signal, it sends this code signal to the digital line 15 via the multimedia multiplexer @13, and also activates the facsimile device 1f14 that is multiplexed with this code signal. Detect the signal shown.

Then, when the line speed control unit 1 detects this signal, the line speed control unit 1
28 Kbit/s synchronization signal to video codec 1
1, a 64 K bit/s synchronization signal, which is two branches of 128 K bit/S, is applied to the video codec 11 and the facsimile device 14, respectively. Further, the code signal sent to the digital line 15 mentioned above is transmitted to the other party's video conference system, and a line speed control section in this system detects a signal indicating activation of the facsimile machine. Also, in the other party's system, the line speed control section is 128 Kbit/
A 64 Kbit/s synchronization signal is applied instead of s to the video codec and the facsimile device, respectively.

Therefore, the video codec 11 is 64Kbit/s.
When a synchronization signal with a bit rate of is input, the image signal input from the video conference device 12 is encoded at the bit rate based on this synchronization signal and is sent to the line speed control section 1. Furthermore, the facsimile device 14 has a 64 Kbit/
When a synchronization signal of s is input, a code signal for facsimile communication is applied to the line speed control section 1 based on this synchronization signal.

When the line speed control unit 1 receives each code signal from the video codec 11 and the facsimile device 14, it multiplexes these code signals into multiplexed 128 k bits.
, /s to the multimedia multiplexer 13. When the multimedia multiplexer 13 receives this signal, it multiplexes this signal together with a code signal input from another terminal (not shown) and sends it out to the digital line 15.

On the other hand, the multimedia multiplexing device 13
The multiplexed signals transmitted via +1-5 are separated into the line speed control unit 1 and other terminal equipment (not shown), and are multiplexed at 128K bit/s into the line speed control unit 1. Add a signal. When the line speed control unit 1 receives this signal, it separates this signal and sends it to the video codec 11 and facsimile machine 14 at 64Kbit/
Add each code signal of s. Therefore, the facsimile device 14 receives a code signal for facsimile communication. Further, when the video codec 11 receives a code signal, it decodes the code signal to form an image signal, and applies this image signal to the video conference device 12 . When the video conference device 12 receives this image signal, it displays an image based on this image signal.

As described above, in this embodiment, when a facsimile device is used, facsimile communication and image transmission are performed at their respective bit rates, and when a facsimile device is not used, the bit rate for facsimile communication is used to perform image transmission. The transmission bit rate is high. Therefore, when a facsimile machine is not used, high-quality image transmission is possible.

[Effects of the Invention] As explained above, according to the present invention, when the attached terminal is not used, the bit rate for image transmission can be increased by using the bit rate for this terminal. A possible video conference system can be provided.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of a video conference system according to the present invention, and FIG. 2 is a block diagram showing a conventional video conference system. 1... line speed control unit, 2... video codec,
12... TV conference device, 13... Multimedia multiplexing device, 14... Facsimile device, 15...
digital line.

Claims (1)

[Claims] A video codec that inputs and outputs image signals to and from a video conference device, a terminal attached to the video conference device, and synchronization of a preset bit rate when the terminal is not used. The video codec is operated based on the signal to digitally communicate the image signal, and when the terminal is used, the video codec and the terminal are operated based on a synchronization signal obtained by dividing the bit rate into two. , and control means for multiplexing the image signal and the communication signal of the terminal and performing digital communication.