JPH03184489A - Data switching controller for multi-spot television conference - Google Patents

Abstract

PURPOSE:To speedily project the picture of a new speaker by switching a selector part when a frame detection part detects the frame of picture data from a terminal sending sound data after these sound data are detected by a speaker detection part. CONSTITUTION:A speaker detection part 2 detects which station the sound data are outputted from. For example, when the speaker detection part 2 detects the sound data of a B station while transmitting the picture data of an A station, a signal showing such a state is transmitted from the speaker detection part 2 to a frame detection part 3. When the frame detection part 3 detects a frame header VH from the picture data from the B station, video selectors 1A-1D are switched so that the picture data from the B station Can be sent to A, C and D stations. Thus, even without displaying the picture of the former speaker while being frozen, the picture of the new speaker can be speedily projected.

Description

[Detailed Description of the Invention] [Summary] A multi-purpose device that is installed between video conference terminals that are placed at multiple locations and that can send and receive audio data and video data, and that controls the switching of data going back and forth between these terminals. Regarding the data switching control device for point video conferencing, the purpose is to control the video of a new speaker so that it can be displayed immediately, and there is a selector that sends video data from a terminal to other terminals other than the own terminal. a speaker detection unit that identifies which terminal the audio data comes from; and a speaker detection unit that detects the audio data and then detects a frame of video data from the terminal that sent the detected audio data. Then, the present invention is configured to include a frame detection section that changes the selector section so that the video data from the C terminal is sent to another terminal. The present invention relates to a multipoint video conference data switching #4 device that is interposed between video conference terminals capable of transmitting and receiving audio data and video data, and controls switching of data going back and forth between these terminals.

In recent years, multipoint audio conference systems have been put into practical use that allow conferences to be held while being located at multiple locations separated from each other.

Furthermore, in order to eliminate the problem caused by the fact that only audio can be transmitted and received during a conference, the multipoint audio conferencing system described above also has a multipoint system that allows video data at each location to be transmitted and received during the conference. A video conferencing system has also been proposed.

In such a multipoint videoconferencing system, it is necessary to control the video data and audio data going back and forth between a plurality of mutually distant terminals. The video conference data switching control device is called a multipoint video conference control device or MCU (Multipoint Conference
e IJnit) is interposed between each terminal.

[Prior Art] FIG. 3 is a schematic block diagram of a multipoint video conference system using a multipoint video conference control device.
As shown in the figure, in a multipoint video conference system, video conference terminals A are installed at multiple locations.

B, C, D (Hereinafter, these terminals will be referred to as A station and B station.

0 station and D station) are arranged, and a multipoint video conference control unit (MCU) 100 is interposed between these stations.

Here, each terminal (station) is configured to be able to send and receive audio data and video data (video data),
For this reason, each station is equipped with a video data and audio data transmission system and a video data and audio data reception system. That is, as shown in FIG. 4, each station includes a television camera 201, A/D converters 202A, 202B, encoders 203A, 203B, microphones 204 . Multiplexer (
MUX) 205 and a monitor 2
06. D/A converter 207A, 207B decoder 208
A, 208B, speaker 209° separation device (DMUX)
210.

Therefore, the video data (analog signal) captured by the television camera 201 is converted into a digital signal by the A/D converter 202A, and then subjected to intraframe encoding or interframe encoding by the encoder 203A. At the same time, the audio data (analog signal) collected by the microphone 204 is converted into a digital signal by the A/D converter 202B, and then subjected to ADPCM encoding by the encoder 203B. The data is multiplexed at multiplexer 205 along with lower speed data such as control data and other optional data to the multipoint video conference controller 10.
It is configured to be sent to the 0 side.

Further, the data from the multipoint video conference control bag W100 is separated into video data, audio data, and low-speed data by a separation device (DMUX) 210, and then the video data is decoded by a decoder 208A. Furthermore, D/A
After being converted back to an analog signal by the converter 207A, the monitor 2
06, the audio data is subjected to inverse ADPCM and decoded by a decoder 208B, further converted back to an analog signal by a D/A converter 207B, and then outputted from a speaker 209.

Furthermore, the multipoint video conference control device gloo controls the switching of data going back and forth between each station, and therefore, the multipoint video conference control device 100 controls the switching of data from each station A to D, as shown in FIG. A video selector unit 101 sends out video data to other stations other than the own station, a speaker detection unit 102 identifies which station the audio data comes from, It also has a mixer part that sends out signals to other stations other than the own station.

Here, the video selector section 101 consists of four video selectors 101A to 101D, the video selector 101A is for sending video data from the BD station to the A station, and the video selector 101B is for sending A, C, This is for sending video data from station D to station B, and the video selector 101C is A.

The video selector 101D sends video data from stations B and D to station C, and the video selector 101D sends video data from stations A to D to station C.
It is sent to the station.

Then, each video selector 101A to 10LD, when audio data is detected by the speaker detection unit 102, transmits the video data from the station where the audio data was detected to another station. Switched to be sent.

[Problems to be Solved by the Invention] However, in such conventional data switching control devices for multipoint video conferences, the video is switched at a timing that ignores the video frame by simply detecting the voice from the speaker. Therefore, an error occurs when switching, and decoding and playback cannot be performed, which causes the video before the switch to be frozen, resulting in the problem that it takes time to display the video of the new speaker. be.

That is, the video data from each station is shown in Figures 6(a) to (d).
) As shown in the figure, synchronization is not achieved, so
For example, while transmitting video data of station A,
When the audio data of station B is detected at the timing shown in
The video data of station B is sent out immediately. As a result, the station that received the video data of station B determines that the video data is completely different from the video data of station A, and determines that an error has occurred. Therefore, after determining that an error has occurred, the system requests the B station to retransmit the video data again, and after receiving the retransmitted video data from the B station, displays the video data from the B station. During this time, the video of station A that had been displayed until now is frozen. When an error occurs as described above, it takes a considerable amount of time (about several tens of seconds) to receive and display the retransmitted video data.

The present invention was made in view of these problems, and
It is an object of the present invention to provide a data switching control device for a multipoint video conference, which can control the video of a new speaker to be displayed promptly.

[Means for Solving the Problems] The present invention also provides a method for controlling switching of data that is interposed between video conference terminals placed at multiple locations and capable of transmitting and receiving audio data and video data, and that is exchanged between these terminals. This invention concerns a data switching control device for multipoint video conferences.

As shown in FIG. 1 (block diagram of the principle of the present invention), the multipoint video conference data switching control device according to the present invention has a selector unit that sends video data from a terminal to other terminals other than the own terminal. 1, a speaker detection unit 2 that identifies which terminal the audio data comes from, and after the speaker detection unit 2 detects the audio data, video data from the terminal that sent the detected audio data. When detecting a frame, a frame detection unit 3 switches the selector unit 1 so that the video data from this terminal is sent to another terminal.
It is composed of the following.

[Function] In the multipoint video conference data switching control device of the present invention described above, after the speaker detection unit 2 detects voice data, the frame detection unit 3 detects the terminal that sent the detected voice data. When a frame of video data from this terminal is detected, the video data from this terminal is sent to other terminals.
The frame detection unit 3 switches the selector unit l.

[Example] Hereinafter, the present invention will be described in detail with reference to the drawings.

Now, also in the case of this embodiment, as shown in FIG. 3, the video conference terminals A and B are placed at multiple locations.

Interposed between C and D (A station, B station, C station, D station),
This example concerns a multipoint video conference control unit W (MCU) 100 that controls switching of data going back and forth between these stations.

Note that each station A to D is configured to be able to transmit and receive audio data, image data (video data), and low-speed data, and the configuration of each station for this purpose is as follows.

Since it is the same as that shown in FIG. 4, its explanation will be omitted.

By the way, FIG. 2 is a block diagram showing a multipoint video conference control device as an embodiment of the present invention.
The multipoint teleconference control device loo shown in the figure includes a video selector section 12, a speaker detection section, a frame detection section 3, and a part of a mixer (not shown).

Here, the video selector unit 1 sends data from stations A-D to other stations other than the own station, and for this purpose, the video selector unit 1 includes four video selectors LA-L.
The video selector 1A is for sending video data from stations BD to station A, and the video selector IB is for sending video data from stations A and CD to station B. 1C sends video data from stations A, B, and D to station C, and the video selector ID is A.
- Video data from station C is sent to station D.

Furthermore, the speaker detection unit 2 identifies which station the audio data comes from, and after the speaker detection unit 2 detects the audio data, the frame detection unit 3 detects the detected audio data. When a frame of video data from the sending station is detected [frame header (VH); see Figure 6], the video selectors IA to IB are switched so that the video data from this station is sent to another station. It is.

Note that a portion of the mixer is used to send audio data from each station A to D to other stations other than the own station.

With the above configuration, for example, if the speaker detection unit 2 detects the audio data of B station at the timing indicated by a (see Fig. 6) while the video data (video data) of station A is being transmitted, the The signal is transmitted from the speaker detection section 2 to the frame detection section 3.

Then, the frame detection unit 3 waits until it detects the frame [frame header (VH)] of the video data from the B station, and detects the frame header (VH) of the video data from the B station (see FIG. 6(b)). When VH) is detected, video data from station B is transferred to A and C.

Video selectors IA to 1D are switched so that the signal is sent to station D.

In this case, the video data sent from station B is intra-frame encoded, so even if you switch from the video data of station A to the video data of station B, the video data sent from station B will be immediately transmitted. It is possible to display footage of a new speaker. This allows the video of a new speaker to be displayed quickly without having to freeze and display the video of the previous speaker, greatly improving the real-time nature of video conferencing. It is.

Note that when the video data from the B station is subsequently sent continuously, interframe encoded data is sent as the video data from the B station for code compression.

Furthermore, the monitor of station B, which has become a new speaker, displays an image of the previous speaker (in this example, the speaker at station A).

In the above example, the case where the speaker changes from station A to station B has been described, but substantially the same operation or effect can be obtained in other cases as well.

Furthermore, it goes without saying that the number of stations is not limited to four as in the above embodiment.

[Effects of the Invention] As described in detail above, according to the data switching control device for multipoint video conference of the present invention, after the speaker detection section detects voice data, the frame detection section detects the detected voice data. When a frame of video data from a terminal that sent audio data is detected, the video data from this terminal will be sent to other terminals.

Since the frame detection section is configured to switch the selector section, it is possible to quickly display the image of a new speaker without having to freeze and display the image of the previous speaker. This has the advantage of greatly promoting the real-time nature of video conferencing.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the principle of the present invention, and FIG. 2 is a block diagram showing an embodiment of the present invention. Fig. 3 is a schematic block diagram of the video conference system, Fig. 4 is a block diagram showing an example of the configuration of each station, Fig. 5 is a block diagram showing a conventional example, and Figs. 6 (a) to (d) are block diagrams showing configuration examples of each station. FIG. 3 is a diagram for explaining a video data frame sequence. In the figure, 1 is a video selector section (selector section), IA to ID are video selectors, 2 is a speaker detection section, 3 is a frame detection section, 100 is a multipoint video conference control device (MCU), 101 is a video selector section, 101A to 101D are video selectors. 102 is a speaker detection unit, 201 is a television camera, 202A and 202B are A/D converters, 203A and 203B are encoders, 204 is a microphone, and 205 is a multiplexer. 206 is a monitor, 207A and 207B are D/A converters, 208A and 208B are decoders, 209 is a speaker, 210 is a separation device, and A-D are stations (video conference terminals).

Claims (1)

[Claims] Interposed between video conference terminals (A to D) located at multiple locations and capable of transmitting and receiving audio data and video data,
In a multipoint video conference data switching control device (100) that controls switching of data going back and forth between the terminals (A to D), video data from the terminals (A to D) is sent to other terminals other than the own terminal. a selector unit (1) for detecting voice data; a speaker detection unit (2) for identifying which terminal the voice data comes from; A frame detection unit (3) is provided which switches the selector unit (1) so that when a frame of video data from a terminal that has sent data is detected, the video data from this terminal is sent to another terminal. A data switching control device for multipoint video conferencing, characterized in that: