JP2698100B2 - Multipoint video conference controller - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a multipoint videoconference in which a plurality of videoconference terminals installed at remote locations are connected to each other and a communication conference is performed between these terminals. Things.

(Prior Art) A conventional multipoint video conference apparatus is configured as shown in FIG. In this figure, reference numerals 1a to 1e denote video conference terminals at a plurality of points (a to e), reference numeral 2 denotes a multipoint video conference control device, and this device includes the following units 3 to 9. That is, 3a to 3e are interface units installed for each of the video conference terminals, 4a to 4e are video processing units, 5a to 5e are video reduction units, 6 is a video multiplex switching unit for each point, 7a to 7e
Is a voice processing unit, 8 is a voice addition unit, 9 is a control unit, and 10a to 10e.
Is a group of lines connecting the video conference terminals 1a to 1e and the multipoint video conference control device 2. In this figure, for the sake of simplicity, transmission lines and exchanges between terminals in the circuit configuration of 10a to 10e are omitted.

Next, the operation will be described. Signals from the five video conference terminals 1a to 1e are input to the respective interface units 3a to 3e of the multipoint video conference controller 2 via the respective line groups 10a to 10e. In order to facilitate the internal processing of the multipoint video conference control device 2, the signal is subjected to code conversion of the received signal in the interface unit, and is separated into a video signal, an audio signal, and a control signal. To 4e, the voice processing units 7a to 7e, and the control unit 9.

First, in each of the video processing units 4a to 4e, each line group 10a to 10e
After decoding the video signal highly efficient encoded by the intra-frame encoding device and the like, and performing horizontal synchronization and vertical synchronization for each line, the video signal is processed using the video memory in the video processing units 4a to 4e. The phases of all video signals on one line are adjusted to the same common phase.

Next, each of the video reduction units 5a to 5e reduces the screen to 1/4 (1/2 in both the horizontal and vertical directions) by thinning out every other pixel in the horizontal and vertical directions of this signal. In the video multiplex switching unit 6, based on the screen designating control signal from the video conference terminal separated by the interface units 3a to 3e, the composite process of the reduced signals from the video reduction units 5a to 5e is performed.
Switching is performed between a desired ground video signal (outputs of the video processing units 4a to 4e) or a reduced composite signal obtained by combining reduced signals (outputs of the video reduction units 5a to 5e).

FIG. 9 shows an example of screen display on the video conference terminal 1a.
(A) is an example of a normal screen (a screen of a normal size that is not reduced) which is a video signal of each ground, and (B) is an example of a reduced composite screen.

On the other hand, the audio signal for each line is
After being separated at 3e, the voice switch of each of the voice processing units 7a to 7e (inserting a loss on the receiving side to reduce sneaking to the transmitting side when talking begins, and inserting a loss to the transmitting side after ending talking to sneak around The audio addition unit 8 mixes and adds the audio signals of the respective video conference terminals (excluding the audio at the own location) for each ground.

Further, it performs encoding of the added audio signal via the audio processing units 7a to 7e and distributes the signal to each TV conference terminal via a line. Here, the control signal from the video conference terminal plays a role of designating any of the ground screen or the reduced composite screen during the conference, and based on this, the video multiplex switching unit 6 transmits the control signal to the corresponding video conference terminal. Control to distribute the specified video signal.

With such a configuration, each video conference terminal displays a screen of a desired point or a reduced composite screen on a monitor or the like of each video conference terminal, and simultaneously listens to all the voices of the ground using speakers or the like. A point-to-point video conference can proceed smoothly.

However, this is because the maximum number of points at which the video conference terminal can communicate is limited by the synthesized screen of the video signal, and the video multiplex switching unit 6 synthesizes a plurality of reduced screens into one screen so that it is not difficult to see, that is, four grounds. It was limited to a five-point conference that reduced the screen to a minute and combined them. As described above, the conventional multipoint video conference has a drawback that it cannot be applied to conferences at six or more locations.

(Object of the Invention) The present invention eliminates the restriction on the number of communication points in the above-described conventional technology, and provides each video conference terminal with an arbitrary positional relationship with respect to a video at a point other than the destination video conference terminal or a reduced video thereof. It is an object of the present invention to provide a multipoint video conference restriction device capable of creating a composite screen.

(Configuration of the Invention) (Differences between the Features of the Invention and the Prior Art) The present invention is connected to video conference terminals installed at at least three or more locations, receives images from each video conference terminal, In a multipoint video conference control device that synthesizes and transmits a video at a location other than the terminal to the video conference terminal, a screen for a video at a location other than the video conference terminal transmitted from each video conference terminal Means for receiving a control signal designating a layout of combination (composition point, presence / absence of reduction, cutout position coordinates, combination position coordinates); means for holding an image of each point and a reduced image of the image of each point; The image of each point and the reduced image of the image of each point are input, and each video conference terminal is displayed on a line-by-line basis at a corresponding position in the line based on the control signal. Turned on and off an image or reduced image that point to, and having a means for creating a synthesized screen of the destination television conference terminal other than the point any position relationship image or its reduced image of the.

In the prior art, as a video composite signal, only the screen reduced to 14 was fixedly synthesized, and all video conference terminals only displayed the same screen. Was cut out to an arbitrary size and combined at a specified position, or cut out at an arbitrary size after being reduced and then combined at a variable position so that it could be combined and displayed at a specified position. Different.

(Embodiment) FIG. 1 shows an example of the configuration of a multipoint video conference control apparatus for a video conference between eight locations according to an embodiment of the present invention. In the figure, reference numerals 1a to 1h denote respective video conference terminals, and reference numeral 13 denotes a multipoint video conference control device, which comprises the following units. That is, 3a to 3h are interface units of each video conference terminal, 4a to 4h are video processing units of each video conference terminal, 5a
5h is a video reduction unit of each video conference terminal, 7a to 7h is an audio processing unit of each video conference terminal, 8 is an audio addition unit, 10a to 10h are line groups corresponding to each video conference terminal, and 11 is a video multiplex switching unit. ,
Reference numeral 12 denotes a control unit.

In this embodiment, as in FIG. 8, an exchange and a transmission line on a line between the television terminal and the video conference control device are omitted.

The difference between the present embodiment and the conventional video conference control devices 2 and 13 is that, in addition to the increase in the number of the line correspondence units, the function of the video multiplex switching unit 11 and the control unit 12 is to combine the screens from the video conference terminals 1a to 1h. Has a function of cutting out a part of the screen in an arbitrary size and synthesizing it at an arbitrary position based on a control signal that specifies the layout (composition point, presence / absence of reduction, cutout position coordinates, synthesis position coordinates). is there.

Hereinafter, the operation will be described focusing on video processing. The fifth
As will be described later with reference to the drawings, prior to the video conference communication, the other party's video conference terminals 1b to 1h are designated by dialing or the like from the start video conference terminal (eg, 1a), and the multipoint video conference controller 13 is switched by the exchange. Set up each line up to.

The video signals from each of the video conference terminals 1a to 1h are code-converted by the interface units 3a to 3h, and then decoded (inverse conversion such as intra-frame coding) by the video processing units 4a to 4h. After synchronization (horizontal synchronization, vertical synchronization, and video frame synchronization) is achieved, the video reduction units 5a to 5h thin out every other pixel in the vertical and horizontal directions of each video signal to create a reduced screen signal.

Further, the video multiplex switching unit 11 cuts out a video signal from each video conference terminal from a specified position or cuts out a reduced signal in order to respond to a screen specification request from each video conference terminal. The cutout signal is synthesized based on the control signal from each video conference terminal, and the superimposed video signal is output to the video processing units 4a to 4h. Further, this video signal is encoded again by the video processing unit, and the audio processing units 7a to 7a
Multiplexed with audio signal from 7h and interface parts 3a to 3h
, And is distributed to the respective video conference terminals 1a to 1h via the line groups 10a to 10h.

Next, the configuration of the video multiplex switching unit 11 is shown in FIG. 2, in which the output of the video processing unit 4a is switched to the video reduction unit during one line period.
The case where the gates of 5b and the image processing units 4c, 4d, 4e are turned on (indicated by ◎) is illustrated. In FIG. 2, 14 is a matrix switch section, 15 is a superimpose section, and 16 is a time adjustment circuit. As shown in the figure, the gate switch of the intersection between the input and output of the matrix switch unit 14 is selected based on an instruction (arrow) from the control unit 12 for a period designated for each line with respect to the video signal of the line to be combined. In this way, the video signal at the designated point is cut out, and these video signals are synthesized.

However, when performing composition, the time adjustment circuit 16 is operated in accordance with an instruction from the control unit 12, and the timing time to the position to be combined is adjusted. FIG. 3 shows an example of the screen after the combination. This screen is obtained by combining the screen at the point c, the screen at the point d, and the screen at the point e with the screen at the point c as the background (large screen). In this case, the screen at the point b is reduced because of the large number of participants. In order to realize this, a control signal for screen designation is used from each of the video conference terminals 1a to 1h to the multipoint video conference control device 13, and a point to be synthesized from the video conference terminal side, possibility of reduction, cutout A control signal for designating a screen composition layout including coordinate positions and composite coordinate positions is notified.

In this example, the composite screen of the points b, c, d, and e is instructed to the line 10a, and the point b designates a reduced screen. The unit 14 selects the video processing units 4c, 4d, and 4e for the periods at points c, d, and e for each line, but selects the image reduction unit (output of a reduced screen) during the period for point b. Repeat for each video field. This selection status is indicated by a double circle at the intersection of the matrix switches 14.

FIG. 4 shows a timing chart in the case of synthesizing the video signal on the line 10a described above. That is, the gate switches are closed in the order of points c, b, c, d, c, e, and c during one line period in the 1/2 field, and the combined screen shown in FIG. 3 is obtained. Further, in the superimpose circuit 15, character information (b, c, d, etc.) indicating a point is displayed in order to easily switch the ground screen.
Is superimposed on the lower right of each cut-out screen, and character information (f, g, h in the case of the line 10a) of a point not displayed on the composite screen is also superimposed.

Next, FIG. 5 shows an example of control signals transmitted and received between the above-described group of video conference terminals 1a to 1h and the multipoint video conference controller 13. As shown in the figure, line setting (A), communication start (B) and communication end (C) are performed between the video conference terminals 2a to 1h and the multipoint video conference controller 13 via the exchange 17. It is. In this example, (a) a call is set from the video conference terminal 1a at the point a to the exchange 17.

(A) The exchange 17 receives a call from the point a, and communicates with the video conference terminals 1b to 1h other than the point a with the multipoint video conference controller.
Call 13 and set the line using the exchange.

(C) The video conference terminal 1a at the point a makes a screen designation (points b, c, d, and e as a composite screen) to the Taketake video conference controller 13 to start communication. In this case, a screen designation (speaker automatic switching) and the like can be performed from the point b or the like as well.
Go to

(D) The above communication is performed between the point a and the points b, c, d, and e. At the end of the communication, a disconnection signal is sent from the point a to the exchange 17, and the exchange is connected to the line such as the point b and the multipoint. The line with the video conference control device 13 is released.

FIG. 6 shows the relationship between the position information (cutout position coordinates and combined position coordinates) on the screen designated by the video conference terminal. Horizontal cut-out position coordinates with selecting the reduced screen as the screen of the point b in the figure x _sb ~x _eb, vertical cutout position coordinates are y _sb ~y _eb. When synthesizing these signals, they start from the sitting position (x _cb , y), so the timing is shifted by the time adjustment circuit 16 by this difference. Since a similar manner the d point in the screen is simply cut out the screen, cut-out position of the horizontal coordinate x _sd ~x _ed, the vertical cut-out position coordinates is y _sd ~y _ed, combining position coordinates (x _cd, y After the timing is shifted by the time adjustment circuit 16 until _cd ), the images are synthesized. The screen at the point e is simply a cut-out screen, similarly to the point d.

When the above-described video processing according to the present invention is compared with the conventional video processing, in the past, it was limited to reducing the screen for four grounds and synthesizing them, but the video multiplex switching unit 11 of the present invention Based on a screen switching control signal from each video conference terminal, a video signal of each ground can be reduced or cut out at a designated place on the screen without being limited to four points, and can be further synthesized. Are different and featured.

As a method of switching the screen, it is also possible to use the function of detecting the speaker and automatically displaying the screen at the position of the speaker. That is, at this time, the speaker is always displayed on the large screen (parent screen serving as a background), and the screens at other points are displayed as small screens (child screens). FIG. 7 shows a screen display example at this time. (A) of the figure is an example in the case where point c is transmitting, and (B) is an example in the case where point b is speaking. At this time, the control unit 12 detects the speaker based on the sound level information detected by the sound processing unit, sends the information to the matrix switch unit 14 and the superimpose unit 15, and selects the gate of the matrix switch. By controlling the period, switching between the parent screen and the child screen in the composite screen and display of undisplayed point information are performed.

On the other hand, the processing of the audio signal according to the present invention is the same as in the prior art. Howling is prevented by using the audio switches 7a to 7h for each line, and the audio adder 8 is completely grounded according to the number of points. Are added (excluding the signal of the own location) and distributed to each line.

In this way, when combining screens at a plurality of points based on instructions from each video conference terminal, the position of each pixel (horizontal direction) and each line (vertical direction) is specified for each line, and the cutout position and the combination By controlling the position, an arbitrary screen combining method becomes possible, and even in the case of six or more spots, a small screen is cut out to enable the screen combining of many points. In addition, instead of displaying on all ground screens, the screen of the point where the main member is present is displayed, and for the points that are not displayed, only the participation (of course the voice is added) is displayed, The number of points can be increased. On the other hand, even in the case of a sub-point video conference with five or fewer points, the present invention allows the composition method of the composite screen to be freely changed for each video conference terminal, so that the screen layout can be designed according to the individuality of the participants. It is now possible to make the screen easier to see.

(Effects of the Invention) As described above, according to the present invention, a screen at an arbitrary position can be cut out and synthesized at an arbitrary position as a method of synthesizing a plurality of points required for a multipoint video conference. It is possible to create a general-purpose composite screen independently for each video conference terminal, and it is possible to flexibly display the screen of the designated ground, and the number of communication points can be expanded by combining many small screens, so that multipoint video conference The application area of is increased.

Furthermore, even when the number of video conference terminals participating in the conference is small, the size and position of the cutout of the composite screen can be freely set, so that the screen is easy to see, and there is an advantage that the conference can be smoothly operated.

In addition, if the speaker is detected and this point is automatically displayed as a background screen, it is not necessary to switch every time the speaker changes, so that there is an advantage that the man-machine interface of the conference participants is improved.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of the configuration of a multipoint video conference control device according to an embodiment of the present invention, FIG. 2 is a diagram showing an example of the configuration of a video multiplex switching unit in FIG. 1, and FIG. FIG. 4 is a timing chart at the time of synthesizing video signals, FIG. 5 is an example of information exchanged between the video conference terminal and the multipoint video conference controller, and FIG. 6 is a coordinate positional relationship at the time of screen synthesis. , FIG. 7 shows a screen display example when speaker automatic switching is used together, FIG. 8 shows a configuration example of a conventional multipoint video conference control device, and FIG. 9 shows a screen display example on a video conference terminal. FIG. 1a to 1h video conference terminal, 3a to 3h interface unit, 4a to 4h video processing unit, 5a to 5h video reduction unit, 7a
... 7h ... audio processing unit, 8 ... addition unit, 10a-10h ... line group, 11 ... video multiplex switching unit, 12 ... control unit, 13 ... multipoint video conference control device, 14 ... switch Matrix part,
15: Superimpose section, 16: Time adjustment circuit.

Claims (1)

(57) [Claims] 1. A video conference terminal connected to at least three or more video conferencing terminals, receives video from each video conference terminal, and transmits video from a location other than the terminal to each video conference terminal. In the multipoint video conference control device that synthesizes and transmits, in the multipoint video conference control device, a screen synthesis layout (composite point, reduction / non-reduction, cut-out position coordinates) for video of a point other than the video conference terminal transmitted from each video conference terminal. Means for receiving a control signal designating the combined position coordinates), means for holding an image of each point and a reduced image of the image of each point, and an image of each point and a reduced image of the image of each point. Based on the control signal, the video of the point to be displayed at the corresponding position in the line or its reduced video is turned on / off for each video conference terminal based on the control signal. And,
Means for creating a composite screen having an arbitrary positional relationship with respect to a video at a point other than the destination video conference terminal or a reduced video thereof.