JPH1028260A - Method for transmitting video data and multipoint video conference device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a video data transmitting method and a multipoint video conference device in which video image quality can be improved, or a video operation can be made smooth. SOLUTION: This is a video data transmitting method in a multipoint video conference device constituted of plural VTS (video remote conference system) terminals and a multipoint video conference unit, connected with the plural VTS terminals through a line. A video 601 to be transmitted from the VTS terminals to the multipoint video conference unit is reduced for preparing one part 602 of an image area, and an area 603 except one part 602 of the image area is transmitted as a video in white or a single color. Thus, the video data transmitting method, in which the video image quality can be improved or the video operation can be made smooth, can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video data transmission method and a multipoint video conference apparatus for holding a conference between a plurality of remote points.

[0002]

2. Description of the Related Art Recently, a plurality of VTSs (Video Teleconfer
encing System, TV teleconferencing system) Terminal MC
Multipoint videoconferencing, in which a conference is established between a plurality of remote points by connecting lines via a U (Multi-point Control Unit, multipoint videoconferencing unit), has come to be held. The MCU transmits audio and video data sent from a VTS terminal connected to the MCU to other VTS terminals connected to the same MCU, and displays images of a plurality of VTS terminals on one screen. It has a function to create multiple screens.

FIG. 9 is a block diagram showing a general multipoint video conference apparatus, and shows a multipoint video conference apparatus between four points. 9, reference numeral 301 denotes an MCU, 302
Is an MCU controller for controlling the MCU, 303 is an ISDN
Network, 304 to 307 are VTS terminals, 308, 310, 3
12, 314 are cameras for taking self-portraits, 309, 311;
313 and 315 are screen display monitors. MCU30
1 and VTSs 304 to 307 are connected by an ISDN network 303.

FIG. 10 is a block diagram showing a conventional MCU constituting the multipoint video conference apparatus shown in FIG. FIG.
, 301 is an MCU, 401 is a multipoint / mixing processing unit, 402 to 405 are blocks, and 406 is an MCU.
407 is a four-point compatible terminal adapter which is an interface with four ISDN lines 410, 408 is a codec (CODEC) unit,
09 is a communication control unit, 412 is a screen synthesizing / multi-screen output unit for synthesizing 4-split screens, 413 is a simple frame switching and distributing unit for switching frames, 414 is an audio mixing unit for switching audio input / output at four points, 415 Is a video encoding / decoding unit for encoding / decoding video data, 416
Is an audio encoding / decoding unit that encodes / decodes audio data, and 417 is a media multiplexing / demultiplexing unit that formats or restores encoded or decoded audio or video data into a specific format. And 418, a connection control unit for controlling a line interface 424, which will be described later, 419, a system management unit for managing communication control, 420, a capability exchange unit for mutually informing the function of the own terminal and the function of the partner terminal, and 421, a multi-function unit. A multi-point control unit for controlling between points, 42
Reference numeral 2 denotes a call control unit for calling a partner terminal; 423, a PC interface (PC I / F) which is an interface with the MCU control device 406; and 424, a line interface which is an interface with a four-point compatible terminal adapter 407.

FIG. 11 is a block diagram showing a conventional VTS terminal constituting the multipoint video conference apparatus shown in FIG. 11, 304 to 307 are VTS terminals, 501 is a block, 502 is a terminal adapter, and 503 is an IS.
DN line, 504 is a codec unit, 505 is a communication control unit, 506 is a video encoding / decoding unit, 507 is an audio encoding / decoding unit, 508 is a media multiplexing / demultiplexing unit, 509
Is a connection control unit, 510 is a system management unit, 511 is a capability exchange unit, 512 is a call control unit, 513 is a PC interface (PC I / F), and 514 is a line interface.

The operation of the multipoint video conference apparatus configured as described above is shown in FIGS. 9, 10, 11, and 1.
This will be described with reference to FIG. First, each of the VTS terminals 304 to
A connection control unit 509 and a call control unit 512 connect the MCU 307 to the MCU 301 via a line interface 514. If the connection is successful, the capability exchange unit 511
Exchange each other's abilities.

Next, video and audio input from the cameras 308, 310, 312 and 314 connected to the respective VTS terminals 304 to 307 are encoded by a video encoding / decoding unit 506,
The encoded data is encoded by the audio encoding / decoding unit 507, and the encoded data is multiplexed by the media demultiplexing unit 508.
The multiplexed coded video and audio data is transmitted to the MCU 301 via the line interface 514, the terminal adapter 502, and the ISDN line 503.

The MCU 301 has ISDN lines 410 and 4
The multiplexed video and audio coded data is received through the point corresponding terminal adapter 407 and the line interface 424, separated by the media multiplexing / demultiplexing unit 417, and then decoded by the video coding / decoding unit 415, and the audio coding / decoding. The image is restored by the unit 416 and the screen composite multi-screen output unit 41
In step 2, the images at the four points are combined into a screen divided into four parts.
The MCU 301 encodes the synthesized video data and the accompanying audio data by the video encoding / decoding unit 415 and the audio encoding / decoding unit 416, and multiplexes the encoded data by the media demultiplexing unit 417. The multiplexed coded video and audio data is transmitted to the line interface 424, the four-point terminal adapter 407, and the ISD.
The data is transmitted to each of the VTS terminals 304 to 307 via the N line 410.

The transmitted data is transmitted to each of the VTS terminals 304 to
307, the screen display monitors 309, 311, 313, and 3 connected to the respective VTS terminals 304 to 307.
15 displays a multi-screen divided into four parts. FIG.
Is a screen diagram showing a multi-screen divided into four parts. FIG.
701 is a multi-screen divided into four, 702 to
705 is a reduced screen corresponding to each of the VTS terminals 304 to 307, and 706 to 709 are video data transmitted from each of the VTS terminals 304 to 307 to the MCU 301. FIG.
As shown in FIG. 2, when the video data 706 to 709 is transmitted from each of the VTS terminals 304 to 307, the four split screen 7
01, the video A of the VTS terminal 304 is displayed on the reduced screen 702 on the upper left, the video B of the VTS terminal 305 on the reduced screen 703 on the upper right, and the video of the VTS terminal 306 on the reduced screen 704 on the lower left. C, a video D of the VTS terminal 307 is displayed on the reduced screen 705 at the lower right.

FIG. 13 is a screen diagram showing video transmission from the MCU 301 to each of the VTS terminals 304 to 307. FIG.
3, reference numeral 1201 denotes a multi-screen divided into four parts;
02 to 1205 are from the MCU 301 to each VTS terminal 304
To 307 are video data.

Next, compression and decompression in video encoding and decoding will be described. International standards for encoding and decoding are based on the ITU recommended by the International Telecommunication Union.
-TH. 261 are used. Normally, video data is compressed and transmitted because the amount of data at the time of encoding becomes very large. At this time, an irreversible compression method with a high compression ratio is used (the method in ITU-T H.261 is This is an irreversible compression method).

[0012]

However, since the conventional multipoint video conference apparatus uses an irreversible compression method with a high compression ratio, the video data is not completely restored to the original state. By repeatedly using the compression method,
When the multi-screen display is performed by the MCU, the image data is compressed and decompressed twice, so that the image quality is greatly degraded and the video operation is smooth. There was a problem that it did not become.

[0013] In the multipoint video conference apparatus and the video data transmission method, it is desired that the video quality can be improved and the video operation can be smoothly performed.

It is an object of the present invention to provide a video data transmission method capable of improving video quality and smoothing video operation, and a multipoint video conference apparatus capable of improving video quality and smoothing video operation. Aim.

[0015]

To solve this problem, a video data transmission method according to the present invention comprises a multi-point video conference unit comprising a plurality of VTS terminals and a multipoint video conference unit connected to the plurality of VTS terminals. A video data transmission method in a point-to-point video conference device, wherein a video transmitted from a VTS terminal to a multipoint video conference unit is reduced to be a part of an image area, and an area other than a part of the image area is white or a single color. This is configured so as to be transmitted as an image.

As a result, it is possible to obtain a video data transmission method in which the video quality is improved and the video operation is smooth.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is directed to a video image in a multipoint video conference apparatus comprising a plurality of VTS terminals and a multipoint video conference unit line-connected to the plurality of VTS terminals. A data transmission method, comprising:
The video transmitted from the TS terminal to the multipoint video conference unit is reduced to form a part of the image area, and the area other than a part of the image area is transmitted as white or single color video. For example, when the number of VTS terminals is four, the effect is that the image area of the video transmitted from each VTS terminal to the multipoint video conference unit is 1/4 of the whole.

According to a second aspect of the present invention, there is provided a multipoint video conference apparatus comprising a plurality of VTS terminals and a multipoint video conference unit line-connected to the plurality of VTS terminals. The image to be transmitted to the point teleconference unit is reduced to be a part of an image area, and an image other than a part of the image area has a video reduction unit for forming a white or single-color image. When there are four VTS terminals, the image area of the video transmitted from each VTS terminal to the multipoint video conference unit is 1
/ 4.

According to a third aspect of the present invention, there is provided a multi-point video conference apparatus comprising a plurality of VTS terminals and a multi-point video conference unit connected to the plurality of VTS terminals by lines. When dividing a plurality of videos corresponding to a plurality of VTS terminals into one screen and transmitting them to each of the plurality of VTS terminals, an image region of a self-image portion of the plurality of videos is converted to a white or single color video. An image reduction unit is provided. For example, when there are four VTS terminals, the image area of the video transmitted from the multipoint video conference unit to each VTS terminal is 3/4 of the whole. Having.

FIG. 1 shows an embodiment of the present invention.
This will be described with reference to FIG. (Embodiment 1) The configuration of a multipoint video conference apparatus according to Embodiment 1 of the present invention is the same as that of FIG. 9 showing a general configuration, and a description thereof will be omitted.

FIG. 1 is a block diagram showing an MCU 301 constituting a multipoint video conference apparatus according to Embodiment 1 of the present invention. In FIG. 1, the multi-point / mixing processing unit 101, the screen synthesizing multi-screen output unit 112, the frame simple switch distribution unit 113, and the audio mixing unit 114 are the multi-point / mixing processing unit 401 and the screen synthesizing multi-screen output unit 412 in FIG. , A simple switching and distribution unit 413 and a sound mixing unit 414, and a description thereof will be omitted. Blocks 102 to 105, MCU control device 1
06, a four-point compatible terminal adapter 107, a codec unit 108, a communication control unit 109, an ISDN line 110,
Video encoding / decoding section 115, audio encoding / decoding section 1
16, media demultiplexing section 117, connection control section 118,
System management unit 119, capability exchange unit 120, multipoint control unit 121, call control unit 122, PC interface 12
3. The line interface 124 is the block 40 in FIG.
2 to 405, MCU control device 406, terminal adapter 407 corresponding to four points, codec section 408, communication control section 409, ISDN line 410, video encoding / decoding section 4
15, audio encoding / decoding unit 416, media demultiplexing unit 417, connection control unit 418, system management unit 419,
Capability exchange section 420, multipoint control section 421, call control section 42
2, PC interface 423, line interface 4
24, and a description thereof will be omitted. 11
Reference numeral 1 denotes an image reduction unit that reduces an image transmitted from a VTS terminal.

FIG. 2 shows VTS terminals 304 to 307 constituting a multipoint video conference apparatus according to Embodiment 1 of the present invention.
FIG. In FIG. 2, block 20
1, terminal adapter 202, ISDN line 203,
Codec section 204, communication control section 205, video encoding /
The decoding unit 206, the voice encoding / decoding unit 207, the media demultiplexing unit 208, the connection control unit 209, the system management unit 210, the capability exchange unit 211, the call control unit 212, the PC interface 213, and the line interface 214 are shown in FIG.
1 block 501, terminal adapter 502, IS
DN line 503, codec section 504, communication control section 50
5, video encoding / decoding section 506, audio encoding / decoding section 507, media demultiplexing section 508, connection control section 50
9, the system management unit 510, the capability exchange unit 511, the call control unit 512, the PC interface 513, and the line interface 514, and the description thereof is omitted. An image reduction unit 215 reduces the image input from the camera (see FIG. 9).

The operation of the multipoint video conference apparatus configured as described above will be described with reference to FIGS. First, after receiving a command to reduce the video to one-quarter and transmit it, the MCU from each of the VTS terminals 304 to 307 receives the command.
The video transmitted to 301 will be described with reference to FIGS. 3, 4, and 5. FIG. 3A is an explanatory diagram showing an image output from the camera, FIG. 3B is an explanatory diagram showing an image reduced to a quarter, and FIG. 3C is a reduced image area and an area outside the reduced image area. FIG. In FIG. 3, reference numeral 601 denotes a camera output video, 602 denotes a reduced video area, and 603 denotes an area outside the reduced video area. FIG. 4 is an explanatory diagram showing a video transmitted from the VTS terminals 304 to 307 to the MCU 301, and FIG.
FIG. 9 is an explanatory diagram showing a video transmitted from the CU 301 to the VTS terminals 304 to 307. In FIG.
7, 808, 809 are VTS terminals 304, 305, 30
6, 307 are images transmitted from MCU 301.
802 to 805 are multi-screens 80
1 is a reduced screen that forms No. 1; In FIG. 5, 13
01 is a multi-screen, 1302-1305 are MCU301
Is a multi-screen transmitted to each of the VTS terminals 304 to 307.

First, as shown in FIG.
The video 601 output from the No. 4 camera 308 is reduced to a quarter by the video reduction unit 215 of the VTS terminal 304.
The reduced video is arranged in the video area 602 in FIG. As shown in FIG. 3C, the reduced video area 60
The area 603 other than 2 is a white image. Similar processing is performed in the VTS terminals 305, 306, and 307. The video area is the upper left in the case of the VTS terminal 304,
In the case of the S terminals 305, 306, and 307, the positions are upper right, lower left, and lower right. That is, each of the VTS terminals 304 to 30
7 is sent to the MCU 301 at 80 in FIG.
6, 807, 808, and 809.
The MCU 301 decodes these images by the image encoding / decoding unit 115 and outputs the images to the screen combining multi-screen output unit 112.
To compose a divided screen (multi-screen) 801. MCU
The video transmitted from 301 to VTS terminals 304 to 307 is obtained by encoding a divided screen in which the self-image of each VTS terminal is a white video as shown in FIG. Even if the self-portrait of each VTS terminal is not directly transmitted from the MCU 301, it is better to combine the self-camera directly into the 4-split screen from the self-camera.
The image quality is improved by not performing the decompression processing. Also, MC
If the self-portrait portion of the 4-split screen transmitted from U301 is transmitted as a white image, the compression ratio increases.

The reason why the compression ratio increases when the above-described video data is transmitted will be described with reference to FIGS. 6, 7 and 8. FIG. FIG. 6 is an explanatory diagram for explaining between frames, and FIG.
(A) is the first transmitted from the VTS terminal to the MCU 301.
FIG. 7 (b) is an explanatory diagram showing a second frame transmitted from the VTS terminal to the MCU 301, and FIG. 8 (a) is a first frame transmitted from the MCU 301 to the VTS terminal. FIG. 8B is an explanatory diagram of the MCU.
FIG. 4 is an explanatory diagram showing a second frame transmitted from the 301 to the VTS terminal. In FIG. 6, reference numerals 901 to 903 denote the first.
7, reference numeral 1001 denotes a first frame, 1004 denotes a second frame, 1002,
1005 is a reduced video area, and 1003 and 1006 are areas other than the reduced video areas 1002 and 1005. In FIG. 8, reference numeral 1101 denotes a first frame, reference numeral 1104 denotes a second frame, reference numerals 1102 and 1105 denote own image areas,
03 and 1106 are areas other than the self-image areas 1102 and 1105.

As shown in FIG. 6, the motion of a moving image is realized by changing a frame corresponding to one frame of a television every time. As described above, when the transmission image is reduced and the image in the region other than the reduced image region is set to white, the ratio of the pixels of the same color existing in one frame increases, and the ratio of the pixel of the same color in the adjacent region increases. The proportion of pixels increases. First frame 1001, 110 in FIGS. 7 and 8
The ratio occupied by one white is 3/4, 1/4, which is considerably large. Further, the first frames 1001, 11
01 and the second frames 1004 and 1104, the color change is small in the white portion, that is, the change between frames is small. This is based on the international standard for digital video compression, ITU-TH. This applies to "orthogonal transform for reducing redundancy in the spatial direction" and "information compression by inter-frame prediction for reducing redundancy in the time direction", which are features of the algorithm of H.261, and compression with a high compression ratio is possible.

Although the margin is white in the present embodiment, a single color other than white may be used. Further, although the number of VTS terminals constituting the multipoint video conference apparatus is four, the present invention can be similarly applied to a multipoint video conference apparatus including three or less or five or more VTS terminals.

As described above, according to the present embodiment, for example, when there are four VTS terminals, the image area of the video transmitted from each VTS terminal to the multipoint video conference unit is reduced to 1/4 of the whole. In addition, since the image area of the video transmitted from the multipoint video conference unit to each VTS terminal can be reduced to 3/4 of the entire area, the change between moving image frames can be reduced. As a result, the compression ratio of the moving image can be increased.

[0029]

As described above, according to the video data transmission method of the present invention, when there are four VTS terminals, each VTS
Since the image area of the video transmitted from the terminal to the multipoint video conference unit can be reduced to 1/4 of the entire area, the change between video frames can be reduced, and the compression rate of the video is increased. This has the advantageous effect of being able to do so.

Further, according to the multipoint video conference apparatus of the present invention, by providing the VTS terminal with the video reduction unit, for example, when there are four VTS terminals, each VTS terminal transmits to the multipoint video conference unit. Since each of the image regions of the video can be reduced to 1/4 of the whole, a change between moving image frames can be reduced, and an advantageous effect that a compression ratio of the moving image can be increased can be obtained. .

Further, by providing the video reduction unit in the multipoint video conference unit, for example, when the number of VTS terminals is four, the image area of the video transmitted from the multipoint video conference unit to each VTS terminal is set to the entire area. Therefore, it is possible to reduce a change between moving image frames and to obtain an advantageous effect that a compression ratio of a moving image can be increased.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an MCU constituting a multipoint video conference device according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a VTS terminal included in the multipoint video conference device according to the first embodiment of the present invention.

3A is an explanatory diagram showing an image output from a camera. FIG. 3B is an explanatory diagram showing an image reduced to a quarter. FIG. 3C is an explanatory diagram showing a reduced image area and an area outside the reduced image area.

FIG. 4 is an explanatory diagram showing a video transmitted from a VTS terminal to an MCU.

FIG. 5 is an explanatory diagram showing a video transmitted from an MCU to a VTS terminal.

FIG. 6 is an explanatory diagram for explaining the interval between frames.

FIG. 7 (a) First transmitted from VTS terminal to MCU
(B) Explanatory diagram showing a second frame transmitted from a VTS terminal to an MCU

FIG. 8 (a) First transmitted from MCU to VTS terminal
(B) Explanatory diagram showing a second frame transmitted from the MCU to the VTS terminal

FIG. 9 is a block diagram showing a general multipoint video conference device;

FIG. 10 is a block diagram showing a conventional MCU constituting the multipoint video conference device of FIG. 9;

11 is a block diagram showing a conventional VTS terminal constituting the multipoint video conference device in FIG. 9;

FIG. 12 is a screen diagram showing a multi-screen divided into four parts.

FIG. 13 is a screen diagram showing video transmission from the MCU to each VTS terminal.

[Explanation of symbols]

 Reference Signs List 101 Multi-point / mixing processing unit 102-105, 201 Block 106 MCU control unit 107 4-point compatible terminal adapter 108 Codec unit 109 Communication control unit 110 ISDN line 111, 215 Image reduction unit 112 Screen synthesis multi-screen output unit 113 Simple frame switching Distribution unit 114 Audio mixing unit 115 Video encoding / decoding unit 116 Audio encoding / decoding unit 117 Media demultiplexing unit 118 Connection control unit 119 System management unit 120 Capability exchange unit 121 Multipoint control unit 122 Call control unit 123 PC Interface 124 Line interface 202 Terminal adapter 203 ISDN line 204 Codec (CODEC) unit 205 Communication control unit 206 Video encoding / decoding unit 207 Audio encoding / decoding unit 208 Media Demultiplexing unit 209 Connection control unit 210 System management unit 211 Capability exchange unit 212 Call control unit 213 PC interface (PC I / F) 214 Line interface 215 Image reduction unit 301 MCU 302 MCU control unit 303 ISDN network 304-307 VTS terminal 308 , 310, 312, 314 Camera 309, 311, 313, 315 Monitor

Claims (3)

[Claims] 1. A video data transmission method in a multipoint video conference device comprising a plurality of VTS terminals and a multipoint video conference unit line-connected to the plurality of VTS terminals. A video data transmission method for reducing a video to be transmitted to a point teleconference unit to form a part of an image area, and transmitting an area other than a part of the image area as white or single-color video. 2. A multipoint video conference device comprising a plurality of VTS terminals and a multipoint video conference unit line-connected to the plurality of VTS terminals, wherein the VTS terminal comprises the multipoint video conference unit. A video conferencing apparatus having an image reducing unit that reduces an image to be transmitted to a part of an image region by reducing the image to be transmitted, and converts a region other than a part of the image region into a white or single-color image. 3. A multipoint video conference device comprising a plurality of VTS terminals and a multipoint video conference unit line-connected to the plurality of VTS terminals, wherein the multipoint video conference unit comprises: When a plurality of videos corresponding to a VTS terminal are divided into one screen and transmitted to each of the plurality of VTS terminals, an image region of a self-image portion of the plurality of videos is reduced to a white or single-color video. Multi-point video conference device having a section.