JPS63276938A - Video communication conference system among multi-point - Google Patents

Abstract

PURPOSE:To realize inter-multipoints video communication conference economically by decreasing the quantity if information while taking it into account that the screen is reduced into a size of 1/n in coding a video signal, and receiving n-side of coded data, and decoding them on one screen. CONSTITUTION:When point A is explained as the operation of other points is exactly the same, the number of coded pictures corresponding to the number of points is set automatically or manually to a coder 9 of each point prior to the communication, at first. The coder 9 at the point A reduce and converts a video signal from an image pickup device 1 so as to go to the number of coded picture elements being set and to generate a video signal 23, forms a packet from the video coded data obtained through the coding, adds an address of a remaining point and the result is supplied to a packet switching network 11, from which the information is distributed to each point. The four kinds of video coded data 24-27 of points B-E are sent in time division to the point A, and a multiplex decoder 10 decodes the information in the time division to synthesize it into one video signal 28.

Description

DETAILED DESCRIPTION OF THE INVENTION (11) Technical field to which the invention pertains The present invention relates to a point-to-point video conference system that connects three or more points by video.

(2) Conventional technology FIG. 3 is a diagram explaining a method that has been mainly considered as a method of performing long point-to-point video communication in the past. An encoding device that encodes a signal; 3 a decoding device that decodes encoded video data received from the network and converts it into a video signal; 4 a display device that displays the decoded video signal; 5 a plurality of points. 6 is a switching network that has the function of selecting one of the data signals transmitted from and sending it to all points, and 6 is a switching network that has the function of distributing the data signals transmitted from each point to multiple points. , 7 is a multi-point conference device having a function of decoding encoded video data received from multiple points once, composing them into one screen, further encoding the data, and transmitting the encoded data to each point; 8
is a video signal synthesis device that combines multiple video signals into one.

In FIG. 3(a), the video transmission point is limited to one location.

Other locations are only able to receive video.

In Figure 3(b), video decoding devices for the number of points and one video encoding device are installed at each point, and the video decoding device corresponding to each point is used as the video encoding device for all remaining points. This is a method for connecting and playing on separate display devices, as shown in Figure 3 (C1
This is a method in which images from all points are once collected in a processing node that controls communication between multiple points, decoded and combined, and then encoded again and transmitted to each point.

Of the conventional methods mentioned above, the method shown in Figure 3 (al) allows you to view images from only one location at a time even if you change the transmission point at any time during communication, and although it can be used for purposes such as lectures. , is insufficient for a conference.On the other hand, the third
Figure fbl (In the method of C1, images of all ground planes can be viewed at the same time, but in the method of Figure 3 (bl), the number of points is n.
Then, (n-1) video decoding devices are required for each location, and the number of broadcast lines is 1:(n-1).
The cost required to realize this would be enormous. The method shown in FIG. 3(C) is for encoding video signals.

Since decoding is repeated twice, the video quality is significantly degraded, and even though the video is reduced and synthesized at the multi-point processing nodes, the line that transmits the encoded data from each point to the multi-point processing nodes is This is uneconomical as it requires the ability to transmit encoded data for one screen.

(3) Purpose of the Invention In view of the drawbacks of the conventional systems described above, the present invention makes it possible to economically realize a multipoint video conference system in which images from all locations can be viewed simultaneously.

(4) Structure of the Invention (4-1) Features of the Invention and Differences from the Prior Art In the present invention, when encoding a video signal, nine screens are reduced to a size of 1/H and synthesized. The main feature is that the amount of encoded information is reduced, and when decoding, the encoded data of n videos is received and decoded as one screen. This is significantly different from conventional technology, which encodes a single video as it is and decodes it on the receiving side.

(4-2) Embodiment FIG. 1 is a detailed diagram of the present invention, in which 1 is an imaging device, and 9 is an encoding method for encoding a video signal output from the imaging device and sending it to the vacuum cleaner Hf4. 10 is a multiplex decoding device that decodes a plurality of packet video encoded data received from the network and converts them into video signals; 4 is a display device that displays the decoded video signals; 11 is a display device that displays the decoded video signals received from each point; A packet-switched network that delivers encoded data packets to multiple specified destinations. Further, FIG. 2 is a diagram for explaining the present invention in detail, in which 21 is an image transmitted from each point during point-to-point communication, 22 is an image displayed at each point during point-to-point communication, and 23- 27 is an image sent from each point during point-to-point communication (this figure shows a case where the number of points is 5), and 28 is an image displayed at point A during point-to-point communication.

The operation of the two embodiments will be explained below, focusing on the operation at point A. The operation is exactly the same at other locations.

Prior to communication, the number of pixels to be encoded is automatically or manually set in the encoding device 9 at each point in accordance with the number of locations. A
The encoding device 9 at the spot generates a video signal 23 by reducing the video signal output from the imaging device 1 so that it has a set number of encoding pixels, and further encodes the video signal 23 to obtain the video signal 23. The encoded video data is packetized, the addresses of the remaining points are added to the packet, and the packet is sent to the packet switching network II. The packet switching network 11 distributes packet data received from each point to other points, depending on the address added to the received packet. As a result, four types of encoded video data 24 to 27 from points B to E are sent to point A in a time-division manner. The multiplex decoding device 10 decodes video encoded data received from each point in a time-division manner.

The signals are combined into one video signal 28 and outputted to the display device 4 for nine displays. The screen 28 displayed in this manner has mxn pixels and has sufficient resolution.

Further, the amount of encoded data to be transmitted from the device at each point to the network is approximately 1/4 of the amount of encoded data when one normal number of pixels is encoded.

(5) Detailed Description of the Invention As described above, according to the present invention, an economical point-to-point video conference can be realized by transmitting a minimum amount of encoded data.

[Brief explanation of the drawing]

FIG. 1 is a diagram for explaining the present invention in detail. FIG. 2 is a diagram for explaining the present invention in detail, and FIG. 3 is a diagram for explaining a conventional multipoint video conference system. l...Imaging device, 9...Video encoding device with packet transmission function, IO...Video multiplex decoding device with packet reception function, 11...Packet switching network, 21...Point-to-point communication 22...display image during two-point communication, 23, 24, 25, 26.27...transmitted image during multi-point communication (between 5 points), 28...multi-point communication Display image during communication.

Claims (1)

[Scope of Claims] In multipoint video communication in which video conference terminals installed at n points are connected to each other and a video conference is held between the terminals, the video conference terminal comprises: an image capturing means for capturing an image of a subject; , the number of pixels of the video signal output from the imaging means is 1/(n
-1); means for packetizing encoded video data and sending it to the network; and means for sequentially receiving encoded data packets from point n from the network; ) a means for time-divisionally decoding encoded data received from a point in time in units of one frame, combining it into one video signal and outputting it, and a means for displaying the output video signal; A multipoint video conference system characterized in that communication is performed via a multipoint video conference system.