JPH05328344A - Video exchanging/distributing system - Google Patents

Abstract

PURPOSE:To display a previously registered video information screen during a period from the output of a video switching request from a terminal up to the practical transmission of an intra-frame coded video signal from the terminal in a video distribution system or an inter multi-point video conference. CONSTITUTION:A video information guide screen corresponding to a video transmitting station is previously stored in a guide screen registering part 57 in a video exchange 50. When a receiving terminal outputs a video selection switching request, the exchange 50 outputs an intra-frame coding request to the specified video transmitting station and transmits the video information guide screen read out from the registering part 57 to the receiving terminal up to the detection of an intra-frame coding video corresponding to the request.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a video exchange / distribution system,
In particular, a video distribution system consisting of a plurality of video transmission stations, a plurality of reception terminals, and a video exchange that connects them,
The present invention relates to a video exchange / distribution system such as a multipoint videoconferencing system including a plurality of video transmission / reception terminals and a multipoint videoconferencing control device that performs a videoconference by mutually connecting and controlling them.

[0002]

2. Description of the Related Art Conventionally, as a video exchange distribution system of this type, for example, a video distribution system disclosed in Japanese Patent Laid-Open No. 3-99592 can be mentioned. FIG. 21 is a block diagram showing the configuration of a conventional video distribution system including two video transmission stations, four reception terminals, and a video exchange that connects them.

In the figure, the conventional video distribution system is
The receiving terminals 10 to 40 which receive and display the encoded video signal from the video exchange, the video exchange 50 which distributes the video signal from the transmission source video transmission station to the reception terminal, and the station A which is the transmission source of the broadcast video. Video transmission station 60 and video transmission station 7 of station B
It is composed of 0 and.

Further, the receiving terminal 10 shown in FIG. 21 is an input unit 11 used when the user of the receiving terminal performs a key operation for requesting switching of received video.
And a video selection requesting unit 12 for receiving a user's request from the input unit 11 and outputting a video selection switching request signal to the video exchange 50, and a decoding for decoding the encoded video signal output from the video exchange 50. Unit 13 and decoding unit 13
It is composed of a display unit 14 for displaying a decoded video signal output from the video switching device 50 and a line interface unit 15 for controlling an interface of a transmission path from the video exchange 50. The receiving terminals 20 to 40 have the same configuration. Is.

A conventional video exchange 50 shown in FIG.
Are the video transmission stations 60, 70 for the receiving terminals 10-40.
A transmission video selection unit 51 that selectively transmits the coded video signals (A and B signals shown in the figure) input from the video transmission unit, and detects intra-frame coding of the coded video from the video transmission stations 60 and 70. Receiving the video selection request from the receiving terminals 10 to 40 and instructing the intraframe coding request section 54 of the intraframe coding request, and detecting the intraframe coding. A transmission image control unit 53 that receives a detection notification of an intra-frame encoded signal of the unit 52 and issues an instruction of a video selection switching request to the transmission image selection unit 51 to select an image to be transmitted, and a transmission image control unit. An intraframe coding request unit 54 that outputs an intraframe coding request to the corresponding video transmitting stations 60 and 70 in accordance with an intraframe coding request instruction from the unit 53.
And a terminal interface unit 55 that controls the interfaces of the transmission lines that respectively connect the receiving terminals 10 to 40,
The transmission station interface unit 56 controls the interface of the transmission path connecting the video transmission stations 60 and 70.

Further, the video transmission station 60 shown in FIG.
A video source 61, which is a source of a video signal provided to the users of the receiving terminals 10 to 40 via the video exchange 50, and a high level using intra-frame / inter-frame coding for the video signal from the video source 61. Encoding unit 62 for performing efficient encoding
And an intra-frame coding control unit 63 that receives an intra-frame coding request from the video exchange 50 and instructs the coding unit 62 to perform intra-frame coding, and an interface of a connection transmission line between the video exchange 50. The video transmission station 70 has the same configuration.

FIG. 22 shows the conventional video distribution system shown in FIG. 21. For example, when the user of the receiving terminal 10 makes a request to switch the received video, that is, the receiving terminal is output from the video transmitting station 70 of the B station. 7 is a timing chart showing the operation when the broadcast video displayed on the display unit 14 is instructed to be switched to the broadcast video of the video transmission station 60 of station A.

By the way, between the video transmitting stations 60 and 70 and the video exchange 50, and between the video exchange 50 and the receiving terminals 10 to 40.
High-efficiency coded video signals are transmitted and received on each transmission path between. In general, an intra-frame / inter-frame coding method is used as a high-efficiency coding method for video signals. In this intra-frame / inter-frame coding method, inter-frame coding is performed during normal video signal transmission,
Intra-frame coding is performed only when there is a large difference in the amount of information between consecutive frames of a video signal (that is, only when image movement is intense).

Next, the operation of the conventional video distribution system will be described with reference to FIGS. 21 and 22. First,
The video exchange 50 has a function of selectively distributing the video signals broadcast / transmitted by the video transmission stations 60 and 70 in response to requests from the receiving terminals 10 to 40. In the receiving terminals 10 to 40, the encoded video signal received via the line interface unit 15 is decoded by the decoding unit 13 and displayed on the display unit 14. Now, for example, while the user of the receiving terminal 10 is receiving the encoded video of the video transmitting station 70 of the B station, it is desired to display the video of the video transmitting station 60 of the A station via the input unit 11 to switch the broadcast video. When the request is made, the video selection request unit 12 makes a video selection switching request to the video exchange 50 so that the video of the video transmission station 60 will be transmitted thereafter. However, when the video selection switching request is issued, the video signal received by the receiving terminal 10 is still the video transmitted from the video transmitting station 70 of the B station. That is, the video signal of KBn shown in the timing chart of FIG. 22 is displayed on the display unit 14.

In the video exchange 50, the transmission video control unit 53 receives the video selection switching request signal instructed by the video selection requesting unit 12 of the receiving terminal 10, and the intraframe coding requesting unit 54 receives the intraframe coding. Instruct the conversion request. In the intra-frame coding requesting unit 54, as a pre-process for switching the transmission video from the coded video of the video transmission station 70 of station B to the coded video of the video transmission station 60 of station A, the video transmission station 60 of station A is sent. Request for intraframe coding. At this point, the video signal received by the receiving terminal 10 is still the video transmitted from the video transmitting station 70 of the B station.

In the video transmission station 60 of the A station, the intraframe coding control section 63 receives the intraframe coding request signal from the intraframe coding request section 54 through the line interface section 64. The intraframe coding control unit 63 instructs the coding unit 62 to perform intraframe coding. The encoder 62 intra-frame encodes the video signal from the video source 61 and transmits the encoded video signal to the video exchange 50 via the line interface 64. At this point in time, the video signal received by the receiving terminal 10 is still the video transmitted from the video transmitting station 70 of station B. That is, KB shown in the timing chart of FIG.
The video signals of n, KBn + 1 and KBn + 2 are displayed on the display unit 14.

In the video exchange 50, the video transmission station 6 of station A
The encoded video signal transmitted from 0 is the transmission video selection unit 51.
Is input to the intra-frame coding detection unit 52. The intra-frame coding detection unit 52 detects that the coding system of the coded video signal from the video transmission station 60 of station A is intra-frame coding. Examples of the detection method in the intraframe coding detection unit 52 include the following methods. That is, first, in the encoding unit 62 of the video transmission station 60 of the A station, when performing the intra-frame encoding process of the video signal, a flag indicating the intra-frame encoding process is set in the frame header part of the encoded video signal. . And
Intra-frame coding detector 52 that receives the coded video signal
Detects intra-frame coding by extracting the flag of the coded video signal.

When the transmission video control section 53 is notified of the detection result of the intra-frame coding, the transmission video control section 53 instructs the transmission video selection section 51 to receive the data from the receiving terminal 1.
The in-frame coded video signal (A signal shown in FIG. 21) from the video transmission station 60 is selected and output as the broadcast video to be transmitted to 0. Under the control of the transmission video selection unit 51, the video signal received by the receiving terminal 10 thereafter is A
The image is switched to the image transmitted from the image transmitting station 60 of the station. That is, NA1, KA shown in the timing chart of FIG.
The video signals 1, KA2, KA3, ... Are displayed on the display unit 14.

The timing chart of FIG. 22 shows the broadcast video switching operation of the conventional video distribution system described above. The operation is outlined below. That is, after the video selection switching request is instructed by the user of the receiving terminal, until the intraframe coding detection unit 52 detects intraframe coding, the video displayed on the display unit of the receiving terminal is: This is the video before the video selection switching request. That is, the video signals of KBn, KBn + 1 and KBn + 2 shown in the timing chart of FIG. 22 are displayed. After that, the transmission video selection unit 51 switches the selected video under the control of the transmission video control unit 53, so that the broadcast video of the video transmission station designated by the video selection switching request is displayed on the display unit of the receiving terminal. That is, NA1, KA1, KA2, KA3 shown in the timing chart of FIG.
The video signal of ... will be displayed.

Next, FIG. 23 is composed of four video transmission / reception terminals (hereinafter referred to as a video conference terminal) and a video exchange (hereinafter referred to as a multipoint video conference control device) which connects these to each other for a video conference. FIG. 11 is a block diagram showing a configuration of a conventional multipoint video conference system.

Referring to the figure, the conventional multipoint video conference system has video conference terminals 110, 120, 13 installed at remote points A, B, C, D, respectively.
0 and 140 and a multipoint video conference control device 150 connecting them.

Further, the video conference terminal 110 shown in FIG.
Is a video / audio input unit 111 composed of a camera, a microphone, etc., an encoding unit 112 for highly efficient encoding of video / audio signals input from the video / audio input unit 111, and multipoint video conference control. An intraframe coding control unit 113 which receives an intraframe coding request from the device 150 and gives an instruction for intraframe coding to the coding unit 112.
And a decoding unit 114 for decoding the encoded video / audio signal from the multipoint video conference control device 150, and the decoding unit 1
A video / audio output unit 115 including a monitor, a speaker, etc., which outputs a video / audio signal from the N. 14, and a line interface unit 116 for controlling an interface of a connection transmission path with the multipoint video conference control device 150. The video conferences 120, 130, and 140 have the same configuration.

Further, the conventional multipoint video conference control device 150 shown in FIG.
0, 130, 140, and the video conferences 110, 120, and a transmission video selection unit 151 for selectively transmitting the encoded video signals (A, B, C and D signals shown in the figure) selectively.
Intra-frame coding detection section 152 for detecting intra-frame coding of coded video received from 130 and 140, and transmitted video by detecting a speaker from audio signals received from video conference terminals 110, 120, 130 and 140. A speaker detecting unit 153 for notifying the control unit 154 and a speaker detecting unit 15
3 receives the speaker information, and the intraframe coding request unit 15
5 to request an intraframe coding request, receive an intraframe coded signal detection notification from the intraframe coding detection unit 152, and select a video to be transmitted to the transmission video selection unit 151. For transmitting a video selection switching request, and each video conference terminal 110, 120, 130, 14 according to the instruction of the intra-frame coding request from the transmission video control unit 154.
0, an intraframe coding request unit 155 that outputs an intraframe coding request to 0, and the video conference terminals 110 and 12
0, 130, 140 and a terminal interface unit 156 for controlling the interface of the transmission path.

FIG. 24 shows a conventional multi-point video conference system shown in FIG. 23. For example, after a conference participant who uses the video conference terminal at the point B speaks, the conference using the video conference terminal at the point A is performed. It is a timing chart which shows operation | movement of a multipoint video conference system when a participant speaks.

By the way, as described above, even in the conventional multipoint video conference system, the video conference terminal 11 is used.
High-efficiency-encoded video signals are transmitted and received on each transmission line between 0, 120, 130, 140 and the multipoint video conference control device 150. In general, an intra-frame / inter-frame coding method is used as a high-efficiency coding method for video signals. In this intra-frame / inter-frame coding method, inter-frame coding is normally performed at the time of transmitting a video signal, and only when there is a large difference in the information amount between consecutive frames of the video signal (that is, when the motion of the image is intense. Only) Intra-frame coding is performed.

Next, the operation of the conventional multipoint video conference system will be described with reference to FIGS. 23 and 24. First, the multipoint video conference control device 150, with respect to the video conference terminals 110, 120, 130, 140,
For example, it has a function of detecting a speaker by an audio signal and transferring a video signal transmitted from the video conference terminal that became the speaker to a conference participant who uses another video conference terminal. For example, in the video conference terminal 110 that receives this video signal, the video of the transmission source video conference terminal received via the terminal interface unit 156 is decoded by the decoding unit 114 and displayed on the video / audio output unit 115. Also,
At the same time, the audio signals transmitted from the plurality of video conference terminals used by the speaker and other conference participants are combined and output to the video / audio output unit 115. The above operation is the same when the video conference terminals 120, 130, 140 are the receiving terminals. Further, the processing of the audio signal is not directly related to the video exchange / distribution system of the present invention, and therefore its explanation is omitted.

Now, for example, the video conference terminals 110, 120, 130, 14 installed at respective points A, B, C, D.
In the case where the conference is switched between the conference participants at the B point and the conference participant at the A point when a video conference is held between the conference participants using 0, the description is focused on the video conference terminal at the C point. To do. When the video conference terminal 120 at the point B is recognized as a speaker, the multipoint video conference control device 150 selects the video signal of the video conference terminal 120 at the point B to select the video conference terminal 130 at the point C. Have been sent to. Normally, the encoding unit 1 of the video conference terminal at point B
At 22, high-efficiency encoding is performed by intra-frame encoding, and the encoded video signal is transmitted to the video conference terminal 13 at the point C.
It is sending to 0.

In this state, when the conference participant at the point A speaks and the level of the audio signal output from the video conference terminal 110 becomes high, the speaker detecting unit 153 of the multipoint video conference control device 150 causes the speaker detector 153 of The video conference terminal 110 used by the conference participant at the point is detected as a speaker, and the transmission video control unit 154 is notified accordingly. The transmission video control unit 154 receives the notification and instructs the intraframe coding request unit 155 to request the intraframe coding. The intra-frame coding requesting unit 155 makes an intra-frame coding request to the video conference terminal 110 at the point A selected as the current speaker. However, at the time of making this intra-frame coding request, the video signal received by the video conference terminal 130 at the point C is still the inter-frame coded video from the video conference terminal 120 at the point B. That is, KB shown in the timing chart of FIG.
The video signal of n is displayed on the video conference terminal 130 at the point C.

The video conference terminal 11 at the point A on the transmitting side
In 0, the intra-frame coding control unit 113 receives the intra-frame coding request from the intra-frame coding request unit 155 and instructs the coding unit 112 to perform the intra-frame coding. The encoding unit 112 is the video / audio input unit 1.
The video signal from 11 is intra-frame encoded and transmitted to the multipoint video conference control device 150. Even at this point, C
The video signal received by the video conference terminal 130 at the point is still the video transmitted from the video conference terminal 120 at the point B. That is, K shown in the timing chart of FIG.
The video signals of Bn, KBn + 1 and KBn + 2 are displayed on the video conference terminal 130 at the point C.

In the multipoint video conference control device 150,
The encoded video signal transmitted from the video conference terminal 110 at the point A is input to the transmission video selection unit 151 and the intraframe coding detection unit 152. Intra-frame coding detector 152
Then, it is detected that the coding method of the coded video signal from the video conference terminal 110 at the point A is intraframe coding. When the transmission video control unit 154 is notified of the detection result of this intra-frame coding, the transmission video control unit 154 instructs the transmission video selection unit 151 to transmit the video conference terminal 130 at the point C to the video conference terminal at the point A. The encoded video signal supplied from 110 (see FIG.
A signal) shown in FIG.
Instruct to output to 0. As a result, the video signal received by the video conference terminal 130 at the point C thereafter is switched to the video transmitted from the video conference terminal 110 at the point A. That is, NA1, K shown in the timing chart of FIG.
The video signals A1, KA2, KA3, ... Are displayed on the video conference terminal 130.

The timing chart of FIG. 24 shows the video switching operation of the conventional multipoint video conference system described above. The operation is outlined below. That is, in the video received by the video conference terminal 130 at the point C, the intra-frame coding detection unit 152 detects the speaker terminal after the speaker detection unit 153 of the multi-point video conference control device 150 detects the speaker terminal. The video from the video conference terminal of the previous speaker (the video of the video conference terminal 120 at the point B in the above description) is detected until the intra-frame coding is detected. That is, the video signals of KBn, KBn + 1 and KBn + 2 shown in the timing chart of FIG. 24 are displayed on the video conference terminal 130 at the point C. After that, the transmission video selection unit 151 switches the transmission video under the control of the transmission video control unit 154, so that the video from the video conference terminal newly detected as the speaker is displayed on the video conference terminal 130 at the point C. That is, FIG.
NA1, KA1, KA2 shown in the timing chart of
The video signals of KA3, ... Are displayed.

[0027]

Since the conventional video exchange / distribution system is configured as described above, the frames actually requested by the video signal transmission terminal from the time when the video selection switching request is issued from the receiving terminal. There was a problem that the receiving terminal had to receive the video signal before the video selection switching request until the intra-coded video signal was transmitted. In order to avoid this, when the video exchange switches the transmission video signal without performing intra-frame coding detection when the video selection switching request is issued, the receiving terminal freezes or disturbs the video before the video selection switching request. There was a problem that the signal was received.

That is, in the conventional video distribution system,
From the time the video selection switching request is issued by the receiving terminal until the video transmission station actually transmits the intraframe-encoded video signal according to the request, the receiving terminal receives the video signal before the video selection switching request. Inevitably, or in order to avoid this, if the video exchange switches the transmission video signal without performing intra-frame coding detection when the video selection switching request is issued, the receiving terminal will be There was a problem that the freeze image and the disturbed image signal were received. Similarly, in the conventional multipoint video conference system, after the change of the video conference terminal recognized as the speaker occurs, the video signal actually encoded by the video conference terminal selected as the speaker is intraframe-coded. Until the transmission, the receiving video conference terminal must receive the video signal before the video selection switching request, or the multipoint video conferencing control device generates the video selection switching request to avoid this. If the transmission video signal is switched without performing intra-frame coding detection, the receiving video conference terminal receives a freeze video before the video selection switching request or a disturbed video signal.

The present invention has been made in order to solve the above-mentioned problems, and from the time when a video selection switching request is issued from the receiving terminal, the intra-frame coding is actually performed by the video signal transmitting terminal according to the request. An object of the present invention is to obtain a video exchange distribution system capable of displaying an intra-frame-encoded video information screen registered in advance in the registration means on the screen of the receiving terminal until the video signal is transmitted. Another object of the present invention is to obtain a video exchange distribution system capable of extending the video information screen received at the time of requesting video selection switching for each receiving terminal or each transmitting terminal for a predetermined time. In addition, the receiving terminal can not only display the video information screen regarding the transmitting terminal currently receiving at any occasion, but also can display the video information screen subjected to the intra-frame coding processing for each receiving terminal or for a predetermined time. The purpose is to obtain a video exchange distribution system that can be extended only.

[0030]

In order to achieve the above object, a video exchange / distribution system according to a first aspect of the present invention includes a plurality of video transmitting stations for transmitting a broadcast video signal to a receiving terminal, and a video transmitting station from the video transmitting stations. A video distribution system comprising a video exchange for distributing encoded video signals to receiving terminals, and a plurality of receiving terminals for decoding and displaying the encoded video signals received from the video exchange, wherein the receiving terminals are A video selection requesting means for sending a video selection switching request signal for requesting selection switching of an encoded video signal to be transmitted to a terminal is provided, and the video switching device relates to broadcast video transmitted from each video transmission station. Guide screen registration means for registering a video information guide screen that has been subjected to intra-frame encoding processing, and intra-frame encoding for a video transmission station upon receiving a video selection switching request signal from a receiving terminal And an image information screen registered in the guide screen registration unit relating to the broadcast video of the specified video transmission station when the video selection switching request signal from the receiving terminal is received. After switching the transmission video so that the intra-frame coding of the coded video signal transmitted from the video exchange is detected by the instruction of the intra-frame coding request means, the coded video signal from the video transmission station concerned is detected. Is provided with a transmission video selection unit for controlling to transmit to the receiving terminal, and the video transmission station
Intra-frame encoding control means for instructing intra-frame encoding to an encoding means for receiving an intra-frame encoding request from a video exchange and performing high-efficiency encoding of a video signal from a video source is provided. Is characterized by.

The video exchange / distribution system according to the second aspect of the present invention includes a plurality of video transmission stations for transmitting broadcast video signals to receiving terminals, and a video exchange for distributing encoded video signals from the video transmitting stations to the receiving terminals. And a plurality of receiving terminals for decoding and displaying an encoded video signal received from a video exchange, wherein the receiving terminal selectively switches the encoded video signal to be transmitted to the terminal. A video selection requesting means for transmitting a video selection switching request signal for requesting the video switching device to the video switching device. When receiving the video selection switching request signal from the guide screen registration means for registering and the receiving terminal, the intraframe coding request is sent to the video transmitting station after a predetermined fixed time has elapsed. And a video information screen registered in the guide screen registration unit for the broadcast video of the specified video transmission station when the video selection switching request signal from the receiving terminal is received. The transmitted video is switched to, and after the intraframe coding of the coded video signal transmitted from the video exchange is detected by the instruction of the intraframe coding request means, the coded video signal from the video transmission station is received. The video transmission station is provided with a transmission video selection unit that controls transmission to the terminal, and the video transmission station is an encoding unit that receives an intra-frame encoding request from the video exchange and performs high-efficiency encoding of the video signal from the video source. On the other hand, an intraframe coding control means for instructing intraframe coding is provided.

The video exchange / distribution system according to the third aspect of the present invention includes a plurality of video transmission stations for transmitting broadcast video signals to receiving terminals, and a video exchange for distributing encoded video signals from the video transmitting stations to the receiving terminals. And a plurality of receiving terminals for decoding and displaying the encoded video signal received from the video exchange, wherein the receiving terminal selectively switches the encoded video signal to be transmitted to the terminal. A video selection requesting means for transmitting a video selection switching request signal for requesting the video switching device to the video switching device, and the video switching device displays the video information guidance screen on which the intra-frame coding processing regarding the broadcast video transmitted from each video transmission station Guide screen registration means for registering, and an intra-frame encoding requesting unit for receiving an image selection switching request signal from the receiving terminal and transmitting an intra-frame encoding request to the video transmitting station. When the video selection switching request signal from the receiving terminal is received, the transmission video is switched so as to transmit the video information screen registered in the guide screen registration unit regarding the broadcast video of the specified video transmission station, and After the intraframe coding of the coded video signal transmitted from the video exchange is detected by the instruction of the intraframe coding request means, the coded video signal from the video transmission station is controlled to be transmitted to the receiving terminal. The video transmission station is provided with a transmission video selection means, and the video transmission station performs high-efficiency coding of the video signal from the video source after a lapse of a predetermined fixed time when the intraframe coding request from the video exchange is received. Is provided with delay intraframe coding control means for instructing the intraframe coding.

The video exchange / distribution system according to the fourth aspect of the present invention includes a plurality of video transmission stations for transmitting broadcast video signals to the receiving terminals, and a video exchange for distributing encoded video signals from the video transmitting stations to the receiving terminals. And a plurality of receiving terminals for decoding and displaying encoded video signals received from the video exchange, wherein the receiving terminals are the video information registered in the guide screen registration means of the video exchange. The video exchange includes guide screen requesting means for instructing the video exchange to request a guide screen request signal for transmitting screen information, and the video exchange performs intraframe-encoded video information regarding broadcast video transmitted from each video transmission station. Guide screen registration means for registering a guide screen, and a frame for receiving a guide screen cancellation request signal from a receiving terminal and transmitting an intraframe coding request to a video transmission station. When the guide screen request signal from the inner encoding requesting means and the receiving terminal is received, the transmission video is transmitted so as to transmit the video information screen registered in the guide screen registration section regarding the broadcast video of the specified video transmission station. At the same time as switching, after the intraframe coding of the coded video signal transmitted from the video exchange is detected by the instruction of the intraframe coding request means, the coded video signal from the video transmitting station is transmitted to the receiving terminal. The video transmission station receives the intra-frame coding request from the video exchange and performs high-efficiency coding of the video signal from the video source. Intra-frame coding control means for instructing coding is provided.

The video exchange / distribution system according to the fifth aspect of the present invention is a multi-point video conference terminal for controlling a video conference by connecting a plurality of teleconferencing terminals installed at remote multipoints. A multipoint videoconferencing system including a videoconference control device, wherein the multipoint videoconferencing control device registers an initial screen registration for registering a video information initial screen that has been intraframe-encoded for each videoconference terminal. Means, an intraframe coding request means for transmitting an intraframe coding request to the newly selected source videoconference terminal when a request for switching the source terminal is generated, and a new unit for requesting switching between the source terminals. The video information screen registered in the initial screen registration unit for the selected transmission source video conference terminal is switched to be transmitted, and the intra-frame encoding is required. Transmission video selection for controlling to transmit the encoded video signal from the transmission source video conference terminal after the intra-frame encoding of the encoded video signal transmitted from the transmission source video conference terminal is detected according to the instruction of the means The video conference terminal, which is provided with a means for transmitting and receiving a video signal, receives an intra-frame coding request from the multi-point video conference control device and performs a high efficiency coding of the video signal from the video source. Intra-frame encoding control means for instructing intra-frame encoding is provided.

The video exchange / distributing system according to the sixth aspect of the present invention is a multipoint multipoint control system for controlling a videoconference by connecting a plurality of teleconferencing terminals installed at remote multipoints. A multipoint videoconferencing system including a videoconference control device, wherein the multipoint videoconferencing control device registers an initial screen registration for registering a video information initial screen that has been intraframe-encoded for each videoconference terminal. A delay intraframe coding request means for transmitting an intraframe coding request to a newly selected source videoconference terminal after a lapse of a predetermined time when a source terminal switching request is generated; When switching to transmit the video information screen registered in the initial screen registration unit relating to the newly selected source video conference terminal when a terminal switching request is issued, , The encoded video signal is transmitted from the source video conference terminal after the intra-frame encoding of the encoded video signal transmitted from the source video conference terminal is detected according to the instruction of the intra frame encoding requesting means. The video conferencing terminal, which is equipped with a transmission video selection means for controlling the video signal and transmits and receives the video signal, receives an intra-frame coding request from the multi-point video conferencing control device and encodes the video signal from the video source with high efficiency. Intra-frame coding control means for instructing the intra-frame coding to the performing coding means is provided.

The video exchange / distributing system according to the seventh aspect of the present invention is a multi-point video conference terminal for controlling a video conference by connecting a plurality of video conference terminals installed at remote multipoints. A multipoint videoconferencing system including a videoconference control device, wherein the multipoint videoconferencing control device registers an initial screen registration for registering a video information initial screen that has been intraframe-encoded for each videoconference terminal. Means, an intraframe coding request means for transmitting an intraframe coding request to the newly selected source videoconference terminal when a request for switching the source terminal is generated, and a new unit for requesting switching between the source terminals. The video information screen registered in the initial screen registration unit for the selected transmission source video conference terminal is switched to be transmitted, and the intra-frame encoding is required. Transmission video selection means for controlling to transmit the encoded video signal from the transmission source video conference terminal after the intra-frame encoding of the encoded video signal transmitted from the transmission source video conference terminal is detected according to the instruction of the means. The video conference terminal that transmits and receives the video signal performs high-efficiency coding of the video signal from the video source after a predetermined fixed time has elapsed after receiving the intra-frame coding request from the multi-point video conference control device. Intra-frame coding control means for instructing the coding means to perform intra-frame coding is provided.

Furthermore, the video exchange / distribution system according to the eighth aspect of the present invention includes a plurality of video conference terminals installed at remote multiple points, and an inter-multipoint control for connecting the video conference terminals to control a video conference. A multipoint videoconferencing system including a videoconference control device, wherein the multipoint videoconferencing control device registers an initial screen registration for registering a video information initial screen that has been intraframe-encoded for each videoconference terminal. Means for receiving an initial screen cancellation request signal from the receiving video conference terminal and transmitting an intra frame coding request to the transmitting video conference terminal, and an initial screen from the receiving video conference terminal When the request signal is received, it is switched to transmit the video information screen registered in the initial screen registration section for the specified transmission source video conference terminal. In addition, according to the instruction of the intra-frame encoding requesting means, after the intra-frame encoding of the encoded video signal transmitted from the transmission source video conference terminal is detected, the encoded video signal from the transmission source video conference terminal is transmitted. The video conference terminal that transmits and receives the video signal is provided with a transmission video selection unit that controls so that the multi-point video conference control device includes an initial screen request unit that transmits a transmission request or a cancellation request to the initial screen registration unit. Intraframe coding control means for receiving intraframe coding request from the point-to-point video conference control device and for instructing intraframe coding to the coding means for high efficiency coding of the video signal from the video source It is characterized by having.

[0038]

Therefore, according to the video distribution system of the first invention, the video information screen (guidance screen) corresponding to each video transmission station is provided.
Is stored in advance in the guide screen registration unit of the video exchange, and when the receiving terminal makes a video selection switching request, the video exchange makes an intraframe coding request to the specified video transmission station, and the request is sent. Correspondingly, until the intra-frame coded video signal transmitted from the video transmission station is detected, the video information guide screen regarding the video transmission station read from the guide screen registration unit is transmitted to the receiving terminal, and the video exchange Since the video signal of the specified video transmission station is transmitted to the receiving terminal at the timing when the intra-frame coded signal is detected, the receiving terminal cannot receive the freeze video or the disturbed video signal before the video selection switching request. Absent.

Further, according to the video distribution system of the second invention, the video information guide screen corresponding to each video transmitting station is stored in advance in the guide screen registration section of the video exchange, and the receiving terminal requests the video selection switching. In the case of an intraframe-encoded video signal, the video exchange waits for a predetermined time and makes an intraframe encoding request to the specified video transmission station, and the intraframe-encoded video signal transmitted from the video transmission station in response to the request. Until is detected, the video information guide screen related to the video transmission station read from the guide screen registration unit is transmitted to the receiving terminal, and the video specified at the timing when the intraframe coded signal is detected by the video exchange. Since the video signal of the transmitting station is transmitted to the receiving terminal, the receiving terminal does not receive the freeze video or the disturbed video signal before the video selection switching request, and the video information guide screen is displayed for a certain period of time. It can be.

According to the video distribution system of the third invention, the video information guide screen corresponding to each video transmitting station is stored in advance in the guide screen registration unit of the video exchange, and the receiving terminal makes a video selection switching request. In the case of an intraframe-encoded video signal, the video transmission station specified in response to the intraframe-encoded request from the video exchange waits for a predetermined time to transmit the intraframe-encoded video signal. Is detected by the video exchange, the video information guide screen for the video transmission station read from the guide screen registration unit is transmitted to the receiving terminal, and at the timing when the intraframe-encoded video signal is detected by the video exchange. Since the encoded video signal of the video transmission station specified by the video selection switching request is transmitted to the receiving terminal, the receiving terminal receives the frozen video or the disturbed video signal before the video selection switching request. Not be, it can be a certain period of time display the image information guide screen.

According to the video distribution system of the fourth invention, the video information guide screen corresponding to each video transmission station is stored in advance in the guide screen registration unit of the video exchange, and the receiving terminal makes a guide screen request. In this case, the video information guide screen related to the video transmission station read from the guide screen registration unit is transmitted to the receiving terminal, and when the reception terminal issues a guide screen cancellation request, the encoded video signal of the video transmitting station. Is transmitted to the receiving terminal, the receiving terminal can display the video information guidance screen at any time.

According to the multipoint video conference system of the fifth invention, the video information screen (initial screen) corresponding to each video conference terminal is stored in advance in the initial screen registration unit of the multipoint video conference control device. If the video conference terminal recognized as the speaker changes, the multipoint video conference control device makes an intra-frame coding request to the transmission video conference terminal newly recognized as the speaker, and Until the intra-frame encoded video signal transmitted from the transmitting video conference terminal in response to the request is detected, the video information initial screen relating to the transmitting video conference terminal read from the initial screen registration unit is received. To the video conferencing terminal that was newly recognized as the speaker when the intra-frame encoded video signal was detected by the multipoint video conferencing controller. And it transmits the video signal to a receiving video conference terminal, receiving the television conference terminal does not receive the video signal freezing images and disturbance of the previous video selection switch request.

According to the multipoint video conference system of the sixth aspect of the invention, the video information initial screen corresponding to each video conference terminal is stored in advance in the initial screen registration unit of the multipoint video conference control device, and the talk is performed. When the video conference terminal recognized as the speaker changes, the multipoint video conference control device waits for a predetermined time and issues an intraframe coding request to the transmission video conference terminal newly recognized as the speaker. Done,
Until the intra-frame coded video signal transmitted from the transmitting video conference terminal in response to the request is detected, the video information initial screen for the transmitting video conference terminal read from the initial screen registration unit is received. The multi-point video conference control device transmits the coded video signal of the transmission video conference terminal newly recognized as the speaker to the reception video conference terminal when the intra-frame coded video signal is detected. Therefore, the receiving video conference terminal can display the initial image information screen for a certain period of time without receiving the freeze image or the disturbed image signal before the image selection switching request.

Further, according to the multipoint video conference system of the seventh invention, the video information initial screen corresponding to each video conference terminal is stored in advance in the initial screen registration unit of the multipoint video conference control device, and the talk is performed. If the video conference terminal recognized as the speaker changes, the transmission video conference terminal newly recognized as the speaker in response to the intra-frame coding request instructed from the multipoint video conference control device has a predetermined time. The transmission videoconference terminal read out from the initial screen registration unit until the intraframe-encoded video signal is transmitted after waiting for only that time and the intraframe-encoded video signal is detected by the multipoint videoconference control device. The initial screen of video information regarding the The recognized encoded video signal transmission teleconference terminal has and transmits the received video conference terminal Te,
The receiving video conference terminal can display the initial image information screen for a certain period of time without receiving the freeze image or the disturbed image signal before the image selection switching request.

Further, according to the multipoint video conference system of the eighth invention, the video information initial screen corresponding to each video conference terminal is stored in advance in the initial screen registration unit of the multipoint video conference control device and received. When the video conference terminal makes an initial screen request, the video information initial screen related to the transmission video conference terminal read from the initial screen registration unit is transmitted to the reception video conference terminal, and the initial video screen cancellation request is made from the reception video conference terminal. If so, the encoded video signal of the transmitting video conference terminal is transmitted to the receiving video conference terminal, so that the receiving video conference terminal can display the video information initial screen at any time.

[0046]

Embodiment 1 A preferred embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 is a block diagram showing a configuration of a video distribution system which is a first embodiment of the present invention, which is composed of two video transmission stations, four reception terminals, and a video exchange that connects them. is there.

In the figure, the video distribution system of the first embodiment includes receiving terminals 10 to 40 for receiving and displaying coded video signals from a video exchange, and a video signal from a source video transmitting station to a receiving terminal. It is composed of a video exchange 50 to be distributed, a video transmission station 60 of station A, which is a transmission source of broadcast video, and a video transmission station 70 of station B.

Further, the receiving terminal 10 shown in FIG. 1 is an input unit 11 used when a user of the receiving terminal performs a key operation for requesting switching of received video.
And a video selection requesting unit 12 for receiving a user's request from the input unit 11 and outputting a video selection switching request signal to the video exchange 50, and a decoding for decoding the encoded video signal output from the video exchange 50. Unit 13 and decoding unit 13
It is composed of a display unit 14 for displaying a decoded video signal output from the video switching device 50 and a line interface unit 15 for controlling an interface of a transmission path from the video exchange 50. The receiving terminals 20 to 40 have the same configuration. Is.

Further, the video exchange 5 of the present embodiment shown in FIG.
0 indicates the video transmission stations 60, 7 for the receiving terminals 10-40.
0-coded video signals (A and B signals shown in the figure) or a video information screen (guidance screen) subjected to intra-frame coding output from the guidance screen registration unit 57 (a and b shown in the figure). A transmission video selection unit 51 for selectively transmitting signals), an intra-frame coding detection unit 52 for detecting intra-frame coding of coded video from the video transmission stations 60 and 70, and receiving terminals 10 to 40. Receives an image selection request from the frame, issues an instruction for an intraframe coding request to the intraframe coding request unit 54, and also issues an intraframe coding detection unit 5
2, a transmission image control unit 53 that receives a detection notification of an intra-frame encoded signal and issues an instruction to a transmission image selection unit 51 for a video selection switching request for selecting a video to be transmitted; and a transmission video control unit. According to the instruction of the intra-frame encoding request from 53, the corresponding video transmitting stations 60, 70
An intraframe coding request unit 54 for outputting an intraframe coding request to the terminal and a terminal interface unit 5 for controlling an interface of a transmission line connecting the receiving terminals 10 to 40.
5, a transmission station interface unit 56 that controls the interface of the transmission path that connects the video transmission stations 60 and 70, and a guide for registering the video information screen that is input from the video transmission stations 60 and 70 and that has been subjected to the intra-frame encoding processing. It is composed of a screen registration unit 57.

Further, the video transmission station 60 shown in FIG. An encoding unit 62 that performs high-efficiency encoding using intraframe / interframe encoding on a signal;
An intra-frame encoding control unit 63 that receives an intra-frame encoding request from the video exchange 50 and instructs the encoding unit 62 to perform intra-frame encoding, and the video exchange 50.
And a line interface unit 64 for controlling an interface of a transmission line connected to the video transmission station 70.
Also has the same configuration.

FIG. 2 shows the case where the user of the receiving terminal 10 requests the switching of the received video in the video distribution system of the first embodiment shown in FIG.
The display unit 14 of the receiving terminal which is output from the image transmitting station 70 of the station.
6 is a timing chart showing an operation when an instruction is issued to switch the broadcast video displayed on the display to the broadcast video of the video transmission station 60 of the A station.

By the way, between the video transmission stations 60 and 70 and the video exchange 50, and between the video exchange 50 and the reception terminals 10 to 40.
High-efficiency coded video signals are transmitted and received on each transmission path between. In general, an intra-frame / inter-frame coding method is used as a high-efficiency coding method for video signals. In this intra-frame / inter-frame coding method, inter-frame coding is performed during normal video signal transmission,
Intra-frame coding is performed only when there is a large difference in the amount of information between consecutive frames of a video signal (that is, only when image movement is intense).

Next, the operation of the video distribution system according to the first embodiment will be described with reference to FIGS. First, in the video exchange 50, the video transmission stations 60 and 70 broadcast /
It has a function of selectively distributing a video signal to be transmitted according to a request from the receiving terminals 10 to 40. Receiving terminal 10-40
Then, the encoded video signal received via the line interface unit 15 is decoded by the decoding unit 13 and displayed on the display unit 14. Now, for example, while the user of the receiving terminal 10 is receiving the encoded video of the video transmitting station 70 of the B station, it is desired to display the video of the video transmitting station 60 of the A station via the input unit 11 to switch the broadcast video. When the request is made, the video selection request unit 12 makes a video selection switching request to the video exchange 50 so that the video of the video transmission station 60 will be transmitted thereafter. However, when the video selection switching request is issued, the video signal received by the receiving terminal 10 is still the video transmitted from the video transmitting station 70 of the B station. That is, the video signal of KBn shown in the timing chart of FIG. 22 is displayed on the display unit 14.

In the video exchange 50, the transmission video control unit 53 receives the video selection switching request signal from the video selection requesting unit 12 of the receiving terminal 10, and the transmission video selection unit 51.
A video information screen (guidance screen) regarding the broadcast video of the video transmission station 60 of station A registered in the guidance screen registration unit 57
To select (select signal a shown in FIG. 1). According to this video information screen selection instruction, the transmission video selection unit 51 selects the video information screen of the video transmission station 60 of station A stored in the guidance screen registration unit 57 and transmits it to the reception terminal 10. After that, the video signal received by the receiving terminal 10 is the guide screen registration unit 5 corresponding to the video transmitting station 60 of the A station.
7 video information screen (guidance screen, Ga shown in FIG. 2)
Becomes At the same time, the transmission video control unit 53 instructs the intraframe coding request unit 54 to request the intraframe coding. In the intra-frame coding requesting unit 54, as pre-processing for switching the transmission video from the coded video of the video transmission station 70 of station B to the coded video of the video transmission station 60 of station A,
A request for intra-frame coding is made to the video transmission station 60 of station A. Then, at this time, the video signal received by the receiving terminal 10 is the information about the broadcast video of the video transmitting station 60 of the station A registered in advance in the guide screen registration unit 57, that is,
It is a video information screen (guidance screen) regarding the broadcast video currently transmitted by the video transmission station 60 of station A. Therefore, on the display unit 14 of the receiving terminal 10, a guide screen for displaying the broadcast video program name of the video transmitting station 60 of the A station, the broadcast time, the cast, the presence / absence of billing, etc. is displayed.

In the video transmission station 60 of the A station, the intraframe coding control section 63 receives the intraframe coding request signal via the line interface section 15, and the intraframe coding control section 63 makes the coding section 62. Then, an intra-frame encoding instruction is issued to. The encoding unit 62 uses the video source 6
The video signal from 1 is intra-frame encoded, and the encoded video signal is transmitted to the video exchange 50 via the line interface unit 64. The display unit 14 of the receiving terminal 10 at this point
The video displayed by is the video transmission station 60 of station A described above.
The video information screen (guidance screen) regarding the broadcast video of is still displayed.

In the video exchange 50, the video transmission station 6 of station A
The encoded video signal transmitted from 0 is the transmission video selection unit 51.
Is input to the intra-frame coding detection unit 52. The intra-frame coding detection unit 52 detects that the coding system of the coded video signal from the video transmission station 60 of station A is intra-frame coding. As the detection method in the intraframe coding detection unit 52, as described in the related art, first, in the case where the coding unit 62 of the video transmission station 60 of the A station performs the intraframe coding process of the video signal, A flag indicating the intraframe coding process is set in the frame header portion of the coded video signal. Then, the intraframe coding detection unit 52 of the video exchange 50 that receives the coded video signal detects the intraframe coding by extracting the flag of the coded video signal.

When the transmission video control unit 53 is notified of the detection result of the intra-frame coding, the transmission video control unit 53 instructs the transmission video selection unit 51 to receive the data from the receiving terminal 10.
It is instructed to select and output the coded video signal (A signal shown in FIG. 1) from the video transmission station 60 as the broadcast video to be transmitted to. As a result, the video signal received by the receiving terminal 10 thereafter is switched to the video transmitted from the video transmitting station 60 of the A station. That is, N shown in the timing chart of FIG.
The video signals A1, KA1, KA2, KA3, ... Are displayed on the display unit 14.

The timing chart of FIG. 2 shows the broadcast video switching operation of the video distribution system of the first embodiment described above. The operation is outlined below. That is, after the video selection switching request is instructed by the user of the receiving terminal, until the intraframe coding detection unit 52 detects intraframe coding,
By the control of the transmission video selection unit 51, the video information screen regarding the broadcast video of the video transmission station 60 of the station A registered in advance in the guidance screen registration unit 57 is transmitted. After that, the transmission video selection unit 51 switches the selected video under the control of the transmission video control unit 53, so that the broadcast video of the video transmission station designated by the video selection switching request is displayed on the display unit of the receiving terminal.
That is, NA1, KA shown in the timing chart of FIG.
The video signals of 1, KA2, KA3, ... Are displayed. Note that the operation of the receiving terminal 10 has been described above, but the same applies to the other receiving terminals 20, 30, and 40, and the video information guide screen of the source video transmitting station may be received at the time of requesting a received video selection switching. it can.

Second Embodiment Next, a video distribution system of the second embodiment will be described. FIG. 3 shows two video transmitting stations, four receiving terminals,
It is a block diagram which shows the structure of the video distribution system which is the 2nd Example of this invention comprised from the video exchange which connects them mutually.

In the figure, the video exchange 50 of the video distribution system of the second embodiment replaces the intra-frame coding request unit 54 shown in FIG. 1 with an instruction for an intra-frame coding request from the transmission video control unit 53. Is received, the delayed intra-frame coding request unit 58 is configured to delay the frame by a predetermined time and output the intra-frame coding request signal to the corresponding video transmission station. The other configurations and operations are the same as those of the video distribution system according to the first embodiment, and the description thereof will be omitted.

FIG. 4 shows a case where the user of the receiving terminal 10 requests the switching of the received video in the video distribution system of the second embodiment shown in FIG.
The display unit 14 of the receiving terminal which is output from the image transmitting station 70 of the station.
7 is a timing chart showing an operation when the broadcast video displayed in is switched to the broadcast video of the video transmission station 60 of station A.

Next, the operation of the video distribution system according to the second embodiment will be described with reference to FIGS.
Now, for example, while the user of the receiving terminal 10 is receiving the encoded video of the video transmitting station 70 of station B, A
When a request to switch the broadcast video is made in order to display the video of the video transmission station 60 of the station, the video selection requesting unit 12 sends the video to the video exchange 50 after the video distribution request, similarly to the video distribution system of the first embodiment. A video selection switching request is made to transmit the video of the transmission station 60, and in the video exchange 50, the transmission video control unit 53 instructs the transmission video selection unit 51 to send the video from the guidance screen registration unit 57 to the video transmission station 60 of the A station. Instruct to select the video information screen (guidance screen). According to this video information screen selection instruction, the transmission video selection unit 51 selects the video information screen of the video transmission station 60 of station A stored in the guidance screen registration unit 57 and transmits it to the reception terminal 10. After that, the video signal received by the receiving terminal 10 becomes a video information screen (guidance screen, Ga shown in FIG. 4) of the guidance screen registration unit 57 corresponding to the video transmission station 60 of the A station.

At the same time, the transmission image control section 53
The delayed intra-frame coding request unit 58 is instructed to request the intra-frame coding. Delayed intraframe coding request unit 5
In No. 8, after waiting for a predetermined time (for example, the receiving terminal sets it by notifying the delay time at the time of video selection request), the transmission video is transmitted from the encoded video of the video transmission station 70 of station B to the video of station A. As a preprocessing for switching to the coded video of the station 60, an intraframe coding request is made to the video transmission station 60 of the A station. In FIG. 4, the delay time in the delayed intra-frame coding requesting unit 58 is indicated by Td1. At this point, the video signal received by the receiving terminal 10 is the information about the broadcast video of the video transmitting station 60 of the A station registered in the guide screen registration unit 57 in advance, that is, the video transmitting station 60 of the A station is currently transmitting. It is a video information screen (guidance screen) regarding the broadcast video being played. Therefore, the display unit 14 of the receiving terminal 10 displays a guide screen for displaying the broadcast video program name of the video transmitting station 60 of the A station, the broadcast time, the cast, the presence / absence of billing, and the like.

After that, when the intraframe coding detection section 52 of the video exchange 50 detects that the coding system of the coded video signal from the video transmission station 60 of the A station is intraframe coding, the first Similar to the video distribution system of the embodiment, the transmission video selection unit 51 selects the coded video signal (A signal shown in FIG. 3) from the video transmission station 60 of station A as the broadcast video to be transmitted to the receiving terminal 10. Output. After that, the video signal received by the receiving terminal 10 is switched to the video transmitted from the video transmitting station 60 of the A station. That is, the video signals of NA1, KA1, KA2, ... Shown in the timing chart of FIG. 4 are displayed on the display unit 14.

Although the operation of the receiving terminal 10 has been described above, the other receiving terminals 20, 30, and 40 similarly receive the image information screen (guidance screen) of the image transmitting station at the time of requesting the received image selection switching. can do. In the second embodiment, the delayed intra-frame coding requesting unit 58 has been described as having a delay function, but the same effect is expected even if the transmission video control unit 53 has a similar delay function. it can. Furthermore, in the second embodiment described above, the display time of the video information screen (guidance screen), that is, the delay time is described as being notified by the users of the receiving terminals 10 to 40. May be. However, the effect is further enhanced by making the video exchange 50 hold the initial value and referencing the initial value when there is no notification of the delay time from the users of the receiving terminals 10 to 40.

Third Embodiment Next, a video distribution system of the third embodiment will be described. FIG. 5 shows two video transmitting stations, four receiving terminals,
It is a block diagram which shows the structure of the video distribution system which is the 3rd Example of this invention comprised from the video exchange which connects them mutually.

In the figure, the video transmission station 60 of station A of the video distribution system of the third embodiment replaces the intraframe coding control section 63 shown in FIG. 1, and the intraframe coding request section of the video exchange 50. A delay intra-frame encoding control unit 65 that delays for a predetermined time and outputs an intra-frame encoding request signal to the encoding unit 62 when receiving an intra-frame encoding request instruction from 54 is configured. And The other configurations and operations are the same as those of the video distribution system according to the first embodiment, and the description thereof will be omitted.

FIG. 6 shows, in the video distribution system of the third embodiment shown in FIG. 5, for example, when the user of the receiving terminal 10 requests the switching of the received video, that is, B
The display unit 14 of the receiving terminal which is output from the image transmitting station 70 of the station.
7 is a timing chart showing an operation when the broadcast video displayed in is switched to the broadcast video of the video transmission station 60 of station A.

Next, the operation of the video distribution system according to the third embodiment will be described with reference to FIGS.
Now, for example, while the user of the receiving terminal 10 is receiving the encoded video of the video transmitting station 70 of station B, A
When a request to switch the broadcast video is made in order to display the video of the video transmission station 60 of the station, the video selection requesting unit 12 sends the video to the video exchange 50 after the video distribution request, similarly to the video distribution system of the first embodiment. A video selection switching request is made to transmit the video of the transmission station 60, and in the video exchange 50, the transmission video control unit 53 instructs the transmission video selection unit 51 to send the video from the guidance screen registration unit 57 to the video transmission station 60 of the A station. Instruct to select the video information screen (guidance screen). According to this video information screen selection instruction, the transmission video selection unit 51 selects the video information screen of the video transmission station 60 of station A stored in the guidance screen registration unit 57 and transmits it to the reception terminal 10. Thereafter, the video signal received by the receiving terminal 10 becomes a video information screen (guidance screen, Ga shown in FIG. 6) of the guidance screen registration unit 57 corresponding to the video transmission station 60 of the A station.

At the same time, in the video transmission station 60 of station A, the delayed intraframe coding control section 65 is
When the intraframe coding request is received from the intraframe coding request unit 54, the coding unit waits for a predetermined time (for example, the video provider of the video transmission station 60 of station A sets each video source). An instruction for intraframe coding is given to 62. In FIG. 6, the delayed intraframe coding control unit 65 is used.
The delay time at is shown by Td2.

After that, when the intra-frame coding detection section 52 of the video exchange 50 detects that the coding system of the coded video signal from the video transmission station 60 of station A is intra-frame coding, the first Similar to the video distribution system of the embodiment, the transmission video selection unit 51 selects the coded video signal (A signal shown in FIG. 5) from the video transmission station 60 of station A as the broadcast video to be transmitted to the reception terminal 10. Output. After that, the video signal received by the receiving terminal 10 is switched to the video transmitted from the video transmitting station 60 of the A station. That is, the video signals of NA1, KA1, KA2, ... Shown in the timing chart of FIG. 6 are displayed on the display unit 14.

The timing chart of FIG. 6 shows the broadcast video switching operation of the video distribution system of the third embodiment described above. The operation is outlined below. That is, when the video selection switching request is instructed by the user of the receiving terminal, the transmission video selection unit 52 operates until the intraframe coding detection unit 52 detects intraframe coding after a predetermined waiting time. The video information guide screen regarding the broadcast video of the video transmitting station 60 of the station A pre-registered in the guide screen registration unit 57 under the control of 51 becomes the video displayed on the display unit of the receiving terminal. That is,
The Ga video signal shown in the timing chart of FIG. 6 is displayed. After that, the transmission image selection unit 51 switches the selection image under the control of the transmission image control unit 53.
The broadcast video of the video transmitting station 60 of the station A designated by the video selection switching request is displayed on the display unit of the receiving terminal. That is, NA1, KA1, KA shown in the timing chart of FIG.
The video signals of 2, ..., Will be displayed.

Although the operation of the receiving terminal 10 has been described above, the other receiving terminals 20, 30, and 40 similarly receive the image information screen (guidance screen) of the image transmitting station at the time of requesting the received image selection switching. can do.

Fourth Embodiment Next, a video distribution system according to a fourth embodiment will be described. FIG. 7 shows two video transmitting stations, four receiving terminals,
It is a block diagram which shows the structure of the video distribution system which is the 4th Example of this invention comprised from the video exchange which connects them mutually.

In the figure, the receiving terminal 10 of the video distribution system of the fourth embodiment transmits a video information screen (guidance screen) request to the video exchange 50 in response to a user request input from the input unit 11. A feature is that the guide screen request unit 16 is configured. The receiving terminals 20-40
The configuration of is also the same. Further, other configurations and operations are the same as those of the video distribution system of the first embodiment, and therefore description thereof will be omitted.

FIG. 8 shows a video distribution system of the fourth embodiment shown in FIG. 7 is a timing chart showing an operation when a request for receiving a video information screen regarding a video is issued.

Next, the operation of the video distribution system according to the fourth embodiment will be described with reference to FIGS.
Now, for example, while the user of the receiving terminal 10 is receiving the encoded video of the video transmitting station 60 of the A station, the A
When a guide screen request is made to display a video information screen (guidance screen) regarding the broadcast video of the station's video transmitting station 60, the guide screen requesting unit 16 of the receiving terminal 10 sends a guide screen request to the video exchange 50. Send.

In the video exchange 50, when the transmission video control unit 53 receives the video information screen (guidance screen) request, the guidance screen registration unit 57 is sent to the transmission video selection unit 51.
The user is instructed to select the video information screen (guidance screen) of the video transmission station 60 of station A from (select signal a in FIG. 7). According to this video information screen selection instruction, the transmission video selection unit 51 selects the video information screen of the video transmission station 60 of station A stored in the guidance screen registration unit 57 and transmits it to the reception terminal 10. After that, the video signal received by the receiving terminal 10 is the guide screen registration unit 5 corresponding to the video transmitting station 60 of the A station.
7 video information screen (guidance screen, Ga shown in FIG. 8)
Then, the user of the receiving terminal 10 displays a video information screen (guidance screen) regarding the broadcast video of the video transmitting station currently being received, that is, the broadcast video program name currently being broadcast, the broadcast time, the cast, the presence / absence of charges, etc. You can know from section 14.

Next, following this state, the receiving terminal 1
When the user of 0 requests the cancellation of the video information screen (guidance screen) in order to watch the normal broadcast video through the input unit 11, the guide screen request unit 16 requests the video exchange 50 to send the A
A video information screen cancellation request is transmitted in order to receive the broadcast video of the station's video transmission station 60.

In the video exchange 50, when the transmission video control unit 53 receives the video information screen cancellation request from the receiving terminal 10, it issues an intraframe coding request instruction to the intraframe coding request unit 54. The intra-frame encoding requesting unit 54 instructs the video transmitting station 60 of station A to perform intra-frame encoding. The display unit 14 of the receiving terminal 10 at this point
The video displayed by is the video transmission station 60 of station A described above.
The video information screen (guidance screen) regarding the broadcast video of is still displayed.

In the video transmitting station 60 of the A station, the intraframe coding control section 63 receives the intraframe coding request signal via the line interface section 15, and the intraframe coding control section 63 is transferred to the coding section 62. Intra-frame encoding is instructed to the other side. The encoding unit 62 is a video source 61.
The intra-frame encoding is performed on the video signal from and the encoded video signal is transmitted to the video exchange 50 via the line interface unit 64.

After that, when the intraframe coding detection section 52 of the video exchange 50 detects that the coding system of the coded video signal from the video transmission station 60 of the A station is intraframe coding, the first Similar to the video distribution system of the embodiment, the transmission video selection unit 51 selects the coded video signal (A signal shown in FIG. 7) from the video transmission station 60 of station A as the broadcast video to be transmitted to the reception terminal 10. Output. After that, the video signal received by the receiving terminal 10 is switched to the video transmitted from the video transmitting station 60 of the A station. That is, the video signals of NA1, KA1, KA2, ... Shown in the timing chart of FIG. 8 are displayed on the display unit 14.

The timing chart of FIG. 8 shows the broadcast video switching operation of the video distribution system according to the fourth embodiment described above. The operation is outlined below. That is, when the video information screen (guidance screen) request is instructed by the user of the receiving terminal, the transmission video selection unit 51 of the video exchange 50 operates from the generation of the video information screen request to the video information screen cancellation request. Displays a video information guide screen related to the broadcast video of the video transmitting station 60 of station A registered in advance in the guide screen registration unit 57 (Ga shown in FIG. 8). After that, the transmission image selection unit 5 is controlled by the transmission image control unit 53.
Since 1 switches the selected video, the broadcast video of the video transmission station 60 of station A instructed by the video selection switching request is displayed on the display unit of the receiving terminal.

Although the operation of the receiving terminal 10 has been described above, the other receiving terminals 20, 30, and 40 similarly receive the image information screen (guidance screen) of the image transmitting station at the time of the request to switch the received image selection. can do. Further, in the above-described fourth embodiment, the user of the receiving terminals 10 to 40 has been described as making a video information screen cancellation request in order to receive a normal broadcast video, but as described in the second embodiment. In addition, the video exchange 50 may be provided with a delay function, or the video transmission stations 60 and 70 may be provided with a delay function as described in the third embodiment. Furthermore, if the delay time elapses, or if the user of the receiving terminal makes a video information screen cancellation request,
The effect will be further enhanced by transmitting normal broadcast video.

In the fourth embodiment, the video information screen (guidance screen) regarding the broadcast video of the video transmission station currently being received is displayed. However, when the video information screen is requested, the selection information regarding the video transmission station is displayed. If you can add
Since it is possible to display a video information screen (guidance screen) regarding the broadcast video of another video transmission station, the effect is further enhanced. For example, the timing chart of FIG. 9 shows the broadcast video switching operation of the video distribution system having such a function, but the operation is outlined below. That is, when the 0 user of the receiving terminal 10 is receiving the broadcast video of the video transmitting station 60 of the A station, and gives an instruction for the video information screen request of the video transmitting station of the B station, the transmission video selecting section 51 of the video exchange 50 From the generation of the video information screen request until the video information screen cancellation request is instructed,
Information about the video transmitting station 60 of the B station, which is registered in advance in the guide screen registration section 57, that is, a video information screen (guide screen) about the broadcast video of the video transmitting station 60 of the B station is displayed on the display section of the receiving terminal. Video (Ga shown in FIG. 9)
Is).

Embodiment 5 Next, a multipoint video conference system of a fifth embodiment will be described. FIG. 10 shows a multipoint television that includes four video transmission / reception terminals (hereinafter, videoconferencing terminals) and a video exchange (hereinafter, multipoint videoconferencing control device) that connects these to each other for a videoconference. It is a block diagram which shows the structure of a conference system.

In the figure, the multipoint video conference system of the fifth embodiment is such that remote multipoints A, B, and
The video conference terminals 110, 1 installed at the points C and D
20, 130, 140 and a multipoint video conference control device 150 connecting them.

Further, the video conference terminal 11 shown in FIG.
Reference numerals 0, 120, 130, and 140 respectively denote a video / audio input unit 111 including a camera and a microphone, and a video / audio input unit 111.
An encoding unit 112 that highly-efficiently encodes a video / audio signal input from the audio input unit 111 and an intraframe encoding request from the multipoint video conference control device 150 are received, and the encoding unit 112 receives the request. Intra-frame coding control section 113 for instructing intra-frame coding, decoding section 114 for decoding the coded video / audio signal from multipoint video conference control apparatus 150, and video from decoding section 114
A video / audio output unit 115 including a monitor and a speaker that outputs an audio signal, and a line interface unit 116 that controls an interface of a connection transmission path with the multipoint video conference control device 150.

Further, the multipoint video conference control apparatus 150 of the fifth embodiment shown in FIG.
Coded video signals (A, B, C and D signals shown in FIG. 10) input from 0, 120, 130, 140, or a video information screen (initial screen) from the initial screen registration unit 157.
Intra-frame coding detection for detecting intra-frame coding of the coded video received from the transmission video selection unit 151 that selectively and selectively transmits (a, b, c and d signals shown in FIG. 10) and the input unit 11. And the video conference terminals 110 and 12
A speaker detection unit 153 that detects a speaker from the audio signals received from 0, 130, and 140 and notifies the transmission video control unit 154, and speaker information is received from the speaker detection unit 153, and an intraframe coding request is received. Instructing the intra-frame encoding request to the unit 155, receiving the detection notification of the intra-frame encoded signal of the intra-frame encoding detection unit 152, and selecting the video to be transmitted to the transmission video selection unit 151. To the corresponding video conference terminal 110, 120, 130, 140 in accordance with the instruction of the intra-frame encoding request from the transmission video control unit 154 for instructing the video selection switching request for Intra-frame coding request unit 155 that outputs a coding request
And a terminal interface unit 156 for controlling the interface of the transmission path connecting the video conference terminals 110, 120, 130, 140.

FIG. 11 shows, in the multipoint video conference system of the fifth embodiment shown in FIG. 10, for example, after a conference participant who uses the video conference terminal at point B speaks
9 is a timing chart showing an operation of the multipoint video conference system when a conference participant who uses the video conference terminal at the point A speaks.

By the way, as described above, even in the multipoint video conference system of this embodiment, the transmission lines between the video conference terminals 110, 120, 130 and 140 and the multipoint video conference controller 150 are high. An efficiency coded video signal is transmitted and received. In general, an intra-frame / inter-frame coding method is used as a high-efficiency coding method for video signals. In this intra-frame / inter-frame coding method, intra-frame coding is normally performed at the time of transmitting a video signal, and only when there is a large difference in information amount between consecutive frames of the video signal, that is, when the motion of the image is intense. Only intraframe coding is performed.

Next, the operation of the multipoint video conference system of the fifth embodiment will be described with reference to FIGS. First, the multipoint video conference control device 150
Performs speaker detection on the video conference terminals 110, 120, 130, and 140 by, for example, an audio signal, and uses a video signal transmitted from the video conference terminal that has become the speaker, on another video conference terminal. It has the function of transferring to the conference participants who will In the video conference terminals 110, 120, 130, 140 that have received this video signal, the video received via the terminal interface unit 156 is decoded by the decoding unit 114 and displayed on the video / audio output unit 115. Also,
At the same time, the audio signals transmitted from the plurality of video conference terminals used by the speaker and other conference participants are combined and output to the video / audio output unit 115. The processing of the audio signal is not directly related to the video exchange / distribution system of the present invention, and thus the description thereof is omitted.

Now, for example, the video conference terminals 110, 120, 130, 14 installed at the respective points A, B, C, D.
When a conference is being held between conference participants using 0, attention is paid to the video conference terminal at point C in the case where the speaker shifts from the conference participant at point B to the conference participant at point A. When the conference participant at the point B is recognized as a speaker, the multipoint video conference control device 150 selects the video signal of the video conference terminal 120 at the point B to the video conference terminal 130 at the point C. I am sending. Normal B
The encoding unit 122 of the video conference terminal at the point performs high-efficiency encoding by intra-frame encoding and transmits the encoded video signal to the video conference terminal 130 at the point C.

In this state, when the conference participant at the point A speaks and the level of the audio signal output from the video conference terminal 110 becomes high, the speaker detection unit 153 of the multipoint video conference control device 150 causes the speaker detector 153 of The video conference terminal 110 used by the conference participant at the point is detected as a speaker and notified to the transmission video control unit 154. The transmission image control unit 154 receives this notification, and the transmission image selection unit 1
51 is instructed to select the video information screen (initial screen) of the point A from the initial screen registration unit 157 (FIG. 1).
0 signal a) is selected). Transmission image selection unit 151
In accordance with this video information screen selection instruction, selects the video information screen of the point A stored in the initial screen registration unit 157 and selects C
It is transmitted to the video conference terminal 130 at the point. After that, the C
The video signal received by the video conference terminal 130 at the location is A
This is the video information screen (initial screen, Ga shown in FIG. 11) of the initial screen registration unit 157 of the video conference terminal 110 at the point. At the same time, the transmission video control unit 154 instructs the intraframe coding request unit 155 to request the intraframe coding. The intraframe coding request unit 155 makes an intraframe coding request to the video conference terminal 110 at the point A, which is the current speaker. When this intra-frame coding request is made, the video signal received by the video conference terminal 130 at the point C is registered in advance in the initial screen registration unit 157 and the video conference at the point A newly selected as the speaker. 3 is an initial screen of video information regarding a video signal from the terminal 110. Therefore, the video / audio output unit 115 of the video conference terminal 130 at the point C is displayed on the video conference terminal 11 at the point A.
Point name 0, conference participant name at point A, terminal attributes, FA
The initial screen such as the X number will be displayed.

Video conferencing terminal 11 at point A on the transmitting side
In 0, the intra-frame coding control unit 113 receives the intra-frame coding request from the intra-frame coding request unit 155 and instructs the coding unit 112 to perform the intra-frame coding. The encoding unit 112 is the video / audio input unit 1.
The video signal from 11 is intra-frame encoded and transmitted to the multipoint video conference control device 150. The video received by the video conference terminal 130 at the point C at this point remains the video information screen (initial screen, Ga shown in FIG. 11) of the initial screen registration unit 157 of the video conference terminal 110 at the point A. .

In the multipoint video conference control device 150,
The encoded video signal transmitted from the video conference terminal 110 at the point A is input to the transmission video selection unit 151 and the intraframe coding detection unit 152. Intra-frame coding detector 152
Then, it is detected that the coding method of the coded video signal from the video conference terminal 110 at the point A is intraframe coding. When the transmission video control unit 154 is notified of the detection result of the intra-frame coding, the transmission video control unit 154 instructs the transmission video selection unit 151 to transmit the video conference terminal 130 at the point C to the video conference terminal at the point A. The encoded video signal supplied from 110 (see FIG.
A signal) shown in FIG.
Instruct to output to 0. As a result, the video signal received by the video conference terminal 130 at the point C thereafter is switched to the video transmitted from the video conference terminal 110 at the point A. That is, NA1, K shown in the timing chart of FIG.
The video signals A1, KA2, ... Are displayed on the video conference terminal 130.

The timing chart of FIG. 11 shows the video switching operation of the multipoint video conference system of the fifth embodiment described above, and the operation is outlined below. That is, for the video received by the video conference terminal 130 at the point C, the intra-frame coding detection unit 152 performs intra-frame coding after the speaker detection unit 153 of the multi-point video conference control device 150 detects the speaker. Until it is detected, the image of the video conference terminal that is the new speaker (in the above description, the video conference terminal 11 at the point A) is displayed.
0 image) video information screen (initial screen, G shown in FIG. 11)
a) is selected and transmitted. After that, the transmission video selection unit 151 switches the selected video under the control of the transmission video control unit 154, so that the video from the video conference terminal instructed by the video selection switching request is displayed on the video conference terminal 130 at the point C.

In the fifth embodiment, the operation was described focusing on the video conference terminal 130 at the point C, but the other video conference terminals 110 and 120140 similarly have the following operation when the speaker changes. The video information screen (initial screen) of the video conference terminal to be transmitted can be received.

In the multipoint video conference control device 150 of the fifth embodiment, the video conference terminals 110 and 12 are used.
Regarding the video received by 0, 130, and 140, the video of the video conference terminal that is currently recognized as the speaker is selected and transmitted, and when the speaker changes, the video of the video conference terminal that becomes the new speaker. The description has been made assuming that the information screen (initial screen) is selected and transmitted. However, as shown in FIG. 12, the video conference terminals 110, 120, 130,
The video transmitted to 140 may be controlled according to the request from the video switching requesting units 118, 128, 138, 148 of those video conference terminals.

That is, the video conference terminal 11 of another multipoint video conference system of the fifth embodiment shown in FIG.
0, 120, 130, and 140 are input units 117, 127, 137, and 147 for requesting switching of received video by conference participants who use the respective video conference terminals.
Video switching requesting units 118, 128, 13 for receiving switching requests from the input units 117, 127, 137, 147 and requesting the video conference terminal 150 to switch the received video.
8 and 148. Other configurations are similar to those of the video conference terminal of the multi-point video conference system shown in FIG.

FIG. 13 shows the multipoint video conference system of the embodiment shown in FIG. 6 is a timing chart showing the operation of the multipoint video conference system when a video is requested from the conference terminal 110.

Sixth Embodiment Next, a video distribution system of a sixth embodiment will be described. FIG. 14 is a block diagram showing the configuration of a multipoint videoconferencing system including four videoconferencing terminals and a multipoint videoconferencing control device that connects them to each other to conduct a videoconference.

In the figure, the multipoint video conference system of the sixth embodiment is such that remote multipoints A, B, and
The video conference terminals 110, 1 installed at the points C and D
20, 130, 140 and a multipoint video conference control device 150 connecting them. Then, the multipoint video conference system of the sixth embodiment has a transmission video control unit 154 instead of the intraframe coding request unit 155 of the multipoint video conference system of the fifth embodiment shown in FIG. When an instruction for requesting intra-frame coding is received, a delayed intra-frame coding request unit that delays for a predetermined time and outputs an intra-frame coding request signal to the transmitting video conference terminal recognized as the current speaker. 158 is configured. The other configurations and operations are the same as those of the multipoint video conference system of the fifth embodiment, and therefore the description thereof will be omitted.

FIG. 15 shows, in the multipoint video conference system of the sixth embodiment shown in FIG. 14, for example, after a conference participant who uses the video conference terminal at point B speaks,
9 is a timing chart showing an operation of the multipoint video conference system when a conference participant who uses the video conference terminal at the point A speaks.

Next, the operation of the multipoint video conference system according to the sixth embodiment will be described with reference to FIGS. Now, for example, the video conference terminals 110, 120, 130, 14 installed at respective points A, B, C, D.
When a conference is being held between conference participants using 0, attention is paid to the video conference terminal at point C in the case where the speaker shifts from the conference participant at point B to the conference participant at point A. When the conference participant at the point B is recognized as a speaker and the conference participant at the point A speaks and the level of the audio signal output from the video conference terminal 110 increases, a large number of the fifth embodiment is required. Similar to the point-to-point video conference system, the speaker detection unit 153 of the multi-point video conference control device 150 detects the video conference terminal 110 used by the conference participant at the point A as the speaker, and the transmission video control unit 154. To notify. The transmission video control unit 154 receives this notification and instructs the transmission video selection unit 151 to select the video information screen (initial screen) of the point A from the initial screen registration unit 157 (a shown in FIG. 14). Select the signal). In accordance with this video information screen selection instruction, the transmission video selection unit 151 selects the video information screen of the point A stored in the initial screen registration unit 157 and transmits it to the video conference terminal 130 of the point C. After that, the video signal received by the video conference terminal 130 at the point C becomes a video information screen (initial screen, Ga shown in FIG. 15) of the initial screen registration unit 157 of the video conference terminal 110 at the point A. At the same time, the transmission video control unit 154 instructs the intraframe coding request unit 155 to request the intraframe coding. The intraframe coding request unit 155 makes an intraframe coding request to the video conference terminal 110 at the point A, which is the current speaker. When this intra-frame coding request is made, the video signal received by the video conference terminal 130 at the point C is registered in advance in the initial screen registration unit 157 and the video conference at the point A newly selected as the speaker. 3 is an initial screen of video information regarding a video signal from the terminal 110. Therefore, the video / audio output unit 115 of the video conference terminal 130 at the point C displays the name of the point of the video conference terminal 110 at the point A, A
Initial screens such as conference participant names at the spot, terminal attributes, and fax numbers will be displayed.

In the multipoint video conference control device 150,
When the delayed intraframe coding request unit 158 receives the instruction for the intraframe coding request from the transmission video control unit 154, waits for a predetermined time (for example, the reception video conference terminal sets it by notifying the delay time) before , The intra-frame encoding request is issued to the video conference terminal 110 at the point A. Even at this point, the conference participants of the video conference terminal 130 at the point C are still in the video conference terminal 11 at the point A.
The video information screen (initial screen) regarding 0 will be viewed on the video / audio output unit 115.

After that, when the intra-frame coding detection unit 152 of the multipoint video conference control device detects the intraframe coding, the transmission video control unit as in the multipoint video conference system of the fifth embodiment. Reference numeral 154 designates a coded video signal (A signal shown in FIG. 14) supplied from the video conference terminal 110 at the point A as a video to be transmitted to the video conference terminal 130 at the point C to the transmission video selection unit 151 and C It instructs to output to the video conference terminal 130 at the point. As a result, thereafter, the video conference terminal 13 at the point C
The video signal received by 0 is the video conference terminal 110 at the point A.
Switch to the image sent from. That is, NA1, KA1, KA2, ... Shown in the timing chart of FIG.
Will be displayed on the video conference terminal 130.

The timing chart of FIG. 15 shows the video switching operation of the multipoint video conference system of the sixth embodiment described above, and the operation is outlined below. That is, the video received by the video conference terminal 130 at the point C is detected by the intra-frame coding detection unit 152 after a predetermined time has elapsed after the speaker detection unit 153 of the multi-point video conference control device 150 detected the speaker. Until the intra-frame coding is detected, the video information screen (initial screen, Ga shown in FIG. 15) of the video (video of the video conference terminal 110 at the point A in the above description) relating to the video conference terminal that is the new speaker. Yes) is selected and sent. After that, since the transmission image selection unit 151 switches the selected image under the control of the transmission image control unit 154, the image from the video conference terminal 110 at the point A designated by the video selection switching request is displayed on the video conference terminal 130 at the point C. To be done. That is, the NA shown in the timing chart of FIG.
The video signals of 1, KA1, KA2, ... Are displayed.

In the sixth embodiment, the operation has been described focusing on the video conference terminal 130 at the point C, but the other video conference terminals 110, 120, 140 similarly operate when the speaker changes. The video information screen (initial screen) of the video conference terminal to be transmitted next can be received.

In the sixth embodiment, the delayed intra-frame coding requesting unit 158 has been described as having a delay function. You can expect an effect.

Further, in the multipoint video conference control device 150 of the sixth embodiment, the video conference terminals 110, 1
Regarding the images received by 20, 130, and 140, the image of the video conference terminal currently recognized as the speaker is selected and transmitted, and when the speaker changes, the image of the video conference terminal that becomes the new speaker. Information screen (initial screen)
However, the multipoint video conference system according to the other embodiment of the fifth embodiment (see FIG. 12) is selected and transmitted.
Similarly to the video conference terminals 110, 120, 13
The images to be transmitted to 0 and 140 may be controlled in accordance with the requests of the image switching requesting units 118, 128, 138 and 148 of those video conference terminals.

Seventh Embodiment Next, a multipoint video conference system of a seventh embodiment will be described. FIG. 16 is a block diagram showing the configuration of a multipoint videoconferencing system including four videoconferencing terminals and a multipoint videoconferencing control device that connects them to each other for a videoconference.

In the figure, the multipoint video conference system of the seventh embodiment is such that remote multipoints A, B, and
The video conference terminals 110, 1 installed at the points C and D
20, 130, 140 and a multipoint video conference control device 150 connecting them. The multipoint video conference system of the seventh embodiment replaces the intraframe coding control unit 113 of the multipoint video conference system of the fifth embodiment shown in FIG. When receiving the instruction of the intraframe coding request from the intraframe coding request unit 155 of the device 150, the coding units 112 and 122 are delayed by a predetermined time.
The delay intraframe coding requesting units 119 and 129 for outputting the intraframe coding request signal are configured. The other configurations and operations are the same as those of the multipoint video conference system of the fifth embodiment, and therefore the description thereof will be omitted.

FIG. 17 shows, in the multipoint video conference system of the seventh embodiment shown in FIG. 16, for example, after a conference participant who uses the video conference terminal at point B speaks,
9 is a timing chart showing an operation of the multipoint video conference system when a conference participant who uses the video conference terminal at the point A speaks.

Next, the operation of the multipoint video conference system according to the seventh embodiment will be described with reference to FIGS. Now, for example, the video conference terminals 110, 120, 130, 14 installed at respective points A, B, C, D.
When a conference is being held between conference participants using 0, attention is paid to the video conference terminal at point C in the case where the speaker shifts from the conference participant at point B to the conference participant at point A. When the conference participant at the point B is recognized as a speaker and the conference participant at the point A speaks and the level of the audio signal output from the video conference terminal 110 increases, a large number of the fifth embodiment is required. Similar to the point-to-point video conference system, the speaker detection unit 153 of the multi-point video conference control device 150 detects the video conference terminal 110 used by the conference participant at the point A as the speaker, and the transmission video control unit 154. To notify. The transmission video control unit 154 receives this notification and instructs the transmission video selection unit 151 to select the video information screen (initial screen) of the point A from the initial screen registration unit 157 (a shown in FIG. 16). Select the signal). In accordance with this video information screen selection instruction, the transmission video selection unit 151 selects the video information screen of the point A stored in the initial screen registration unit 157 and transmits it to the video conference terminal 130 of the point C. After that, the video signal received by the video conference terminal 130 at the point C becomes the video information screen (initial screen, Ga shown in FIG. 17) of the initial screen registration unit 157 of the video conference terminal 110 at the point A, and the point A is displayed. Initial screens such as the name of the video conference terminal 110, the conference participants at the point A, the attributes of the terminal, and the FAX number are displayed.

In the video conference terminal 110 at the point A which is the transmission video conference terminal, when the delayed intraframe coding control unit 119 receives the instruction for the intraframe coding request from the multipoint video conference control device 150, a predetermined time period elapses. After waiting (for example, setting is performed by the transmission video conference terminal notifying the delay time), the encoding unit 112 is instructed of the intraframe encoding request. Encoding unit 112
Intra-frame encodes the video signal from the video / audio input unit 111 and transmits it to the multipoint video conference control device 150. At this point, the video information screen (initial screen) regarding the video conference terminal 110 at the point A is still displayed on the video conference terminal 130 at the point C.

After that, when the intraframe coding detection unit 152 of the multipoint videoconference control device detects the intraframe coding, the transmission video control unit as in the multipoint video conference system of the fifth embodiment. Reference numeral 154 designates a coded video signal (A signal shown in FIG. 14) supplied from the video conference terminal 110 at the point A as a video to be transmitted to the video conference terminal 130 at the point C by the transmission video selection unit 151, and selects C. Instruct to output to the video conference terminal 130 at the point. As a result, thereafter, the video conference terminal 13 at the point C
The video signal received by 0 is the video conference terminal 110 at the point A.
Switch to the image sent from. That is, NA1, KA1, KA2, ... Shown in the timing chart of FIG.
Will be displayed on the video conference terminal 130.

The timing chart of FIG. 17 shows the video switching operation of the multipoint video conference system of the seventh embodiment described above. The operation is outlined below. That is, the video received by the video conference terminal 130 at the point C is detected by the intra-frame coding detection unit 152 after a predetermined time has elapsed after the speaker detection unit 153 of the multi-point video conference control device 150 detected the speaker. Until the intra-frame encoding is detected, the video information screen (initial screen, Ga shown in FIG. 17) of the video (video of the video conference terminal 110 at the point A in the above description) relating to the video conference terminal that is the new speaker. Yes) is selected and sent. After that, since the transmission image selection unit 151 switches the selected image under the control of the transmission image control unit 154, the image from the video conference terminal 110 at the point A designated by the video selection switching request is displayed on the video conference terminal 130 at the point C. To be done. That is, the NA shown in the timing chart of FIG.
The video signals of 1, KA1, KA2, ... Are displayed.

In the seventh embodiment, the operation was described focusing on the video conference terminal 130 at the point C, but the same applies to the other video conference terminals 110, 120 ... 140 when the speaker changes. The video information screen (initial screen) of the video conference terminal to be transmitted next can be received.

In the multipoint video conference control apparatus 150 of the seventh embodiment, the video conference terminals 110 and 12 are used.
Regarding the video received by 0, 130, and 140, the video of the video conference terminal that is currently recognized as the speaker is selected and transmitted, and when the speaker changes, the video related to the video conference terminal that becomes the new speaker. Although it has been described that the information screen (initial screen) is selected and transmitted, the video conference terminals 110 and 120 are similar to the multipoint video conference system (see FIG. 12) of the other examples of the fifth example. , 13
The images to be transmitted to 0 and 140 may be controlled in accordance with the requests of the image switching requesting units 118, 128, 138 and 148 of those video conference terminals.

Eighth Embodiment Next, a multipoint video conference system of an eighth embodiment will be described. FIG. 18 is a block diagram showing the configuration of a multipoint videoconferencing system including four videoconferencing terminals and a multipoint videoconferencing control device that connects them to each other for a videoconference.

In the figure, the multipoint video conference system of the eighth embodiment receives a request from the input units 117 and 127 and requests a video information screen (initial screen) to the multipoint video conference control device 150. Initial screen request unit 21
1 and 221 are configured. The other configurations and operations are the same as those of the multipoint video conference system of the fifth embodiment, and therefore the description thereof will be omitted.

FIG. 19 shows, in the multipoint video conference system of the eighth embodiment shown in FIG. 18, for example, after a conference participant who uses the video conference terminal at point B speaks.
9 is a timing chart showing an operation of the multipoint video conference system when a conference participant who uses the video conference terminal at the point A speaks.

Next, the operation of the multipoint video conference system according to the eighth embodiment will be described with reference to FIGS. Now, for example, the video conference terminals 110, 120, 130, 14 installed at respective points A, B, C, D.
When a video conference is held between the conference participants who use 0, the conference participant who uses the video conference terminal at the point C is receiving an image of the video conference terminal 110 at the point A and the input unit 137 not shown. Video information screen (initial screen) via
When requesting the video information, the initial screen requesting unit 231 (not shown) requests the multipoint video conference controller 150 to receive the video information screen (initial screen) of the video currently being received. Make a request.

In the multipoint video conference control device 150,
When the transmission video control unit 154 receives the request for the video information screen (initial screen), the transmission video selection unit 151 selects the video information screen (initial screen) of the point A from the initial screen registration unit 157. Instruct (select signal a shown in FIG. 18). In accordance with this video information screen selection instruction, the transmission video selection unit 151 selects the video information screen of the point A stored in the initial screen registration unit 157 and transmits it to the video conference terminal 130 of the point C. After that, the video conference terminal 130 at the point C becomes the video information screen (initial screen, Ga shown in FIG. 19) of the initial screen registration unit 157 of the video conference terminal 110 at the point A, which is the video currently being received,
The initial screen of the name of the video conference terminal 110 at the point A, the conference participants at the point A, the attributes of the terminal, the FAX number, etc. will be displayed.

Next, while the conference participants who use the video conference terminal at the point C are receiving the video information screen (initial screen) about the video conference terminal 110 at the point A, the normal information is input via the input unit 137 (not shown). When the cancellation of the video information screen (initial screen) is requested to display the received video, the initial screen request unit 231 (not shown) causes the multipoint video conference controller 150 to display the normal video information to display the received video. Request to cancel the screen (initial screen).

In the multipoint video conference control device 150,
When the transmission video control unit 154 receives the request for canceling the video information screen (initial screen), it instructs the intraframe coding request unit 155 to request the intraframe coding. The intraframe coding request unit 155 determines that the source A
An intraframe coding request is made to the video conference terminal 110 at the point. At the time of making this intra-frame coding request, the video signal received by the video conference terminal 130 at the point C is the video information about the video signal from the video conference terminal 110 at the point A that is registered in the initial screen registration unit 157 in advance. The initial screen remains.

The video conference terminal 11 at the point A on the transmitting side
In 0, the intra-frame coding control unit 113 receives the intra-frame coding request from the intra-frame coding request unit 155 and instructs the coding unit 112 to perform the intra-frame coding. The encoding unit 112 is the video / audio input unit 1.
The video signal from 11 is intra-frame encoded and transmitted to the multipoint video conference control device 150. The video received by the video conference terminal 130 at the point C at this point remains the video information screen (initial screen, Ga shown in FIG. 19) of the initial screen registration unit 157 of the video conference terminal 110 at the point A. ..

After that, when the intraframe coding detection unit 152 of the multipoint videoconference control device detects the intraframe coding, the transmission video selection unit similarly to the multipoint video conference system of the fifth embodiment. 151 selects an encoded video signal (A signal shown in FIG. 18) supplied from the video conference terminal 110 at the A point as an image to be transmitted to the video conference terminal 130 at the C point, and outputs it to the video conference terminal 130 at the C point. Instruct them to do so. As a result, the video signal received by the video conference terminal 130 at the point C thereafter is switched to the video transmitted from the video conference terminal 110 at the point A. That is, NA1, KA shown in the timing chart of FIG.
The video signals of 1, KA2, ... Are displayed.

The timing chart of FIG. 19 shows the video switching operation of the multipoint video conference system of the eighth embodiment described above, and the operation is outlined below. That is, regarding the video received by the video conference terminal 130 at the point C, the transmission video selection unit 151 of the inter-multipoint video conference control device 150 releases the video information screen (initial screen) when the request is issued. Until that time, the video information screen (initial screen, Ga shown in FIG. 19) of the video relating to the video conference terminal currently being received (the video of the video conference terminal 110 at the point A in the above description) is selected and transmitted. After that, since the transmission image selection unit 151 switches the selection image under the control of the transmission image control unit 154, the A selected by the image selection switching request is instructed.
The video from the video conference terminal 110 at the point is displayed on the video conference terminal 130 at the point C. That is, the video signals of NA1, KA1, KA2, ... Shown in the timing chart of FIG. 19 are displayed.

In the eighth embodiment, the operation has been described by focusing on the video conference terminal 130 at the point C, but the other video conference terminals 110, 120, 140 similarly operate when the speaker changes. The video information screen (initial screen) of the video conference terminal to be transmitted next can be received.

In the eighth embodiment, the conference participants of the receiving video conference terminals 110, 120, 130 and 140 make the video information screen cancellation request in order to receive the normal received video. However, the multipoint video conference control device 150 may be provided with a delay function as described in the sixth embodiment, and the transmission video conference terminals 110 and 120 may be provided as described in the seventh embodiment. , 13
0 and 140 may have a delay function. Further, when the delay time elapses or when the video conference screen cancel request of the video conference terminals 110, 120, 130, 140 is received, the effect is further enhanced by transmitting the normal broadcast video.

In the eighth embodiment, the video information screen (initial screen) of the video conference terminal currently being received is displayed. However, when the video information screen is requested, the selection information about the video conference terminal to be received is displayed. If it can be added, the video information screen (initial screen) of another video conference terminal can be displayed, so that the effect is further enhanced.

For example, the timing chart of FIG.
The video switching operation of another multipoint video conference system of the eighth embodiment having such a function is shown, and the operation is outlined below.
That is, while the conference participants of the video conference terminal 130 at the point C are receiving the transmission video of the video conference terminal 110 at the point A, after instructing the video information screen request of the video conference terminal 120 at the point B, the video information concerned is displayed. When the screen cancellation request is issued, information on the video conference terminal 120 at the point B registered in the initial screen registration unit 157, that is, between the generation of the video information screen request and the instruction of the video information screen cancellation request, that is, The video information screen (initial screen) regarding the video conference terminal 120 at the point B becomes the video displayed on the display unit of the video conference terminal 130 at the point C (Ga shown in FIG. 20).

[0135]

As described above, according to the video distribution system of the first invention, the video information screen (guidance screen) corresponding to each video transmission station is stored in advance in the guidance screen registration unit of the video exchange, When the receiving terminal makes a video selection switching request, the video exchange makes an intraframe coding request to the specified video transmission station, and the intraframe code transmitted from the video transmission station in response to the request. Until the encoded video signal is detected, the video information guide screen regarding the video transmission station read from the guide screen registration unit is transmitted to the receiving terminal,
Since the video switch is configured to transmit the coded video signal of the video transmission station specified by the video selection switching request to the receiving terminal at the timing when the intra-frame coded video signal is detected, the receiving terminal requests the video selection switching request. Does not receive the previous freeze video or disturbed video signal, but receives the video information guide screen (broadcast video program name, broadcast time, performers, billing etc.) regarding the video conference terminal specified by the video selection switching request Therefore, the service for the user of the receiving terminal can be improved.

Further, according to the video distribution system of the second invention, the video information guide screen corresponding to each video transmitting station is stored in advance in the guide screen registration section of the video exchange, and the receiving terminal requests the video selection switching. In the case of a video transmission, the video exchange waits for a predetermined time and makes an intraframe encoding request to the specified video transmission station, and the intraframe encoded video signal transmitted from the video transmission station in response to the request. Until is detected, the video information guide screen related to the video transmission station read from the guide screen registration unit is transmitted to the receiving terminal, and video selection switching is performed at the timing when the intraframe coded video signal is detected by the video exchange. Since it is configured to transmit the encoded video signal of the video transmission station specified in the request to the receiving terminal,
The receiving terminal does not receive the freeze video or the disturbed video signal before the video selection switching request, and can display the video information guidance screen for the video conference terminal specified by the video selection switching request for a certain period of time, and the service for the user of the reception terminal. There is an effect that can improve.

According to the video distribution system of the third invention, the video information guide screen corresponding to each video transmitting station is stored in advance in the guide screen registration section of the video exchange, and the receiving terminal requests the video selection switching. In the case of an intraframe-encoded video signal, the video transmission station designated in response to the intraframe-encoded request from the video exchange waits for a predetermined time to transmit the intraframe-encoded video signal. Is detected by the video exchange, the video information guide screen for the relevant video transmission station read from the guide screen registration unit is transmitted to the receiving terminal, and the video exchange detects the intraframe coded video signal at the timing. Since it is configured to send the encoded video signal of the video transmission station specified by the video selection switching request to the receiving terminal, the receiving terminal can freeze the video before the video selection switching request Not receiving a video signal, can certain time displays video information guide screen about the video conference terminal specified by the image selection switching request, there is an effect that it is possible to improve the service for the user of the receiving terminal.

Further, according to the video distribution system of the fourth invention, the video information guide screen corresponding to each video transmitting station is stored in advance in the guide screen registration unit of the video exchange, and the receiving terminal requests the guide screen. In this case, the video information guide screen related to the video transmission station read from the guide screen registration unit is transmitted to the receiving terminal, and when the reception terminal requests cancellation of the guide screen, the encoded video signal of the video transmitting station. Is configured to be transmitted to the receiving terminal, the receiving terminal has the effect of being able to display the video information guidance screen at any time.

According to the multipoint video conference system of the fifth invention, the video information screen (initial screen) corresponding to each video conference terminal is stored in advance in the initial screen registration section of the multipoint video conference control device. When the video conference terminal recognized as the speaker changes, the multipoint video conference control device makes an intra-frame coding request to the transmission video conference terminal newly recognized as the speaker, and Until the intra-frame coded video signal transmitted from the transmitting video conference terminal in response to the request is detected, the video information initial screen relating to the transmitting video conference terminal read from the initial screen registration unit is received. To the video conferencing terminal that was newly recognized as the speaker when the intra-frame encoded video signal was detected by the multipoint video conferencing control device. Since the video signal is configured to be transmitted to the receiving video conference terminal, the receiving video conference terminal does not receive the freeze video or the disturbed video signal before the video selection switching request and is recognized as the speaker. Even if a change occurs, the video information initial screen (point name,
The name of the conference participant, the attribute of the terminal, the FAX number, etc.) can be displayed, and the service of the video conference terminal for the conference participant can be improved.

According to the multipoint video conference system of the sixth aspect of the invention, the video information initial screen corresponding to each video conference terminal is stored in advance in the initial screen registration unit of the multipoint video conference control device. When the video conference terminal recognized as the speaker changes, the multipoint video conference control device waits for a predetermined time and issues an intraframe coding request to the transmission video conference terminal newly recognized as the speaker. Done,
Until the intra-frame coded video signal transmitted from the transmitting video conference terminal in response to the request is detected, the video information initial screen for the transmitting video conference terminal read from the initial screen registration unit is received. The multi-point video conference control device transmits the coded video signal of the transmission video conference terminal newly recognized as the speaker to the reception video conference terminal when the intra-frame coded video signal is detected. With this configuration, the receiving video conference terminal does not receive the freeze video or the disturbed video signal before the video selection switching request, and even if the video conference terminal recognized as the speaker changes, The video information initial screen related to the video conference terminal recognized as the speaker can be displayed for a certain period of time, and the service for the conference participants of the video conference terminal can be provided. There is an effect that it is possible to above.

Further, according to the multipoint video conference system of the seventh invention, the video information initial screen corresponding to each video conference terminal is stored in advance in the initial screen registration unit of the multipoint video conference control device, and the talk If the video conferencing terminal recognized as the speaker changes, the transmission video conferencing terminal newly recognized as the speaker in response to the intra-frame coding request instructed from the multipoint video conferencing control device will have a predetermined time. The transmission videoconference terminal read out from the initial screen registration unit until the intraframe-encoded video signal is transmitted, and the intraframe-encoded video signal is detected by the multipoint videoconference control device. The initial screen of video information regarding the Since it is configured to transmit the encoded video signal of the transmitting video conference terminal recognized by the receiving video conference terminal to the receiving video conference terminal, the receiving video conference terminal does not receive the freeze video or the disturbed video signal before the video selection switching request. Even if the video conference terminal recognized as the speaker changes, the video information initial screen for the video conference terminal newly recognized as the speaker can be displayed for a certain period of time. There is an effect that the service can be improved.

Further, according to the multipoint video conference system of the eighth invention, the video information initial screen corresponding to each video conference terminal is stored in advance in the initial screen registration unit of the multipoint video conference control device and received. When the video conference terminal makes an initial screen request, the video information initial screen that is read from the initial screen registration section and then related to the transmitting video conference terminal is transmitted to the receiving video conference terminal, and the receiving video conference terminal requests initial screen cancellation. In such a case, since the encoded video signal of the transmitting video conference terminal is configured to be transmitted to the receiving video conference terminal, the receiving video conference terminal can display the video information initial screen at any time. effective.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a video distribution system according to a first embodiment.

FIG. 2 is a diagram illustrating a case where the receiving terminal 10 requests the image of the image transmitting station 60 of the A station while the receiving terminal 10 is receiving the image output from the image transmitting station 70 of the B station in the image distribution system of the first embodiment. 6 is a timing chart showing a switching operation.

FIG. 3 is a block diagram showing a configuration of a video distribution system according to a second embodiment.

FIG. 4 is a diagram showing a case where the receiving terminal 10 requests the image of the image transmitting station 60 of the A station while the receiving terminal 10 is receiving the image output from the image transmitting station 70 of the B station in the image distribution system of the second embodiment. 6 is a timing chart showing a switching operation.

FIG. 5 is a block diagram showing a configuration of a video distribution system according to a third embodiment.

FIG. 6 is a diagram illustrating a case where the receiving terminal 10 requests the image of the image transmitting station 60 of the station A while the receiving terminal 10 is receiving the image output from the image transmitting station 70 of the station B in the image distribution system of the third embodiment. 6 is a timing chart showing a switching operation.

FIG. 7 is a block diagram showing a configuration of a video distribution system according to a fourth embodiment.

FIG. 8 is a video information screen (guidance screen) of the video transmitting station of the A station while the receiving terminal 10 is receiving the video output from the video transmitting station 60 of the A station in the video distribution system of the fourth embodiment. 6 is a timing chart when a request is made.

FIG. 9 is a video information screen of a video transmitting station 70 of the B station while the receiving terminal 10 is receiving the video output from the video transmitting station 60 of the A station in another video distribution system of the fourth embodiment. It is a timing chart when a (guidance screen) is requested.

FIG. 10 is a block diagram showing a configuration of a multipoint video conference system according to a fifth example.

FIG. 11 is a timing chart when the video conference terminal at the point C switches to the terminal image at the point A while the video conference terminal at the point C is receiving the video from the terminal at the point B in the multipoint video conference system according to the fifth example. is there.

FIG. 12 is a block diagram showing the configuration of another multipoint video conference system according to the fifth example.

FIG. 13 is a timing when the video conference terminal at the point C switches to the terminal video at the point A while receiving the video from the terminal at the point B in another multipoint video conference system according to the fifth embodiment. It is a chart.

FIG. 14 is a block diagram showing a configuration of a multipoint video conference system according to a sixth example.

FIG. 15 is a timing chart when the video conference terminal at the point C switches to the terminal image at the point A while receiving the video from the terminal at the point B in the multipoint video conference system according to the sixth embodiment. is there.

FIG. 16 is a block diagram showing a configuration of a multipoint video conference system according to a seventh embodiment.

FIG. 17 is a timing chart when the video conference terminal at the point C switches to the terminal image at the point A while receiving the video from the terminal at the point B in the multipoint video conference system according to the seventh embodiment. is there.

FIG. 18 is a block diagram showing the configuration of a multipoint video conference system according to an eighth example.

FIG. 19 shows a case where the video conference screen at the point C requests the video information screen (initial screen) while receiving the video from the device at the point A in the multipoint video conference system according to the eighth embodiment. It is a timing chart.

FIG. 20 is a video information screen of the video conference terminal at the point B while the video conference terminal at the point C is receiving the video from the terminal at the point A in another multipoint video conference system according to the eighth embodiment. It is a timing chart when a (initial screen) is requested.

FIG. 21 is a block diagram showing a configuration of a conventional video distribution system.

FIG. 22 shows a switching operation in the conventional video distribution system when the receiving terminal 10 receives the video output from the video transmitting station 70 of the B station and requests the video of the video transmitting station 60 of the A station. It is a timing chart.

FIG. 23 is a block diagram showing a configuration of a conventional multipoint video conference system.

FIG. 24 is a timing chart when the video conference terminal at the point C switches to the terminal image at the point A while receiving the video from the terminal at the point B in the conventional multipoint video conference system.

[Explanation of symbols]

10, 20, 30, 40 Receiving terminal 11, 21, 31, 41 Input section 12, 22, 32, 42 Video selection requesting section 13, 23, 33, 43 Decoding section 14, 24, 34, 44 Display section 15, 25, 35, 45 Line interface section 16, 26, 36, 46 Guidance screen request section 50 Video switch 51 Transmitted video selection section 52 Intra-frame coding detection section 53 Transmitted video control section 54 In-frame coding request section 55 Terminal interface section 56 transmitter station interface unit 57 guide screen registration unit 58 delayed intra-frame coding request unit 60, 70 video transmitter station 61, 71 video source 62, 72 coding unit 63, 73 intra-frame coding control unit 64, 74 line interface unit 65, 75 Delayed intraframe coding control unit 110, 120, 130, 140 Levi conference terminal 150 Multi-point video conference control device 111, 121, 131, 141 Video / audio input unit 112, 122, 132, 142 Encoding unit 113, 123, 133, 143 In-frame encoding control unit 114, 124, 134, 144 Decoding section 115, 125, 135, 145 Video / audio output section 116, 126, 136, 146 Line interface section 117, 127, 137, 147 Input section 118, 128, 138, 148 Video switching request section 119, 129, 139, 149 Delayed intra-frame coding control unit 211, 221, 231, 241 Initial screen request unit 151 Transmission video selection unit 152 In-frame coding detection unit 153 Speaker detection unit 154 Transmission video control unit 155 In-frame coding Request unit 156 Terminal B Interface unit 157 initial screen registration unit 158 delays the intraframe coding request unit

Claims (8)

[Claims] 1. A plurality of video transmitting stations for transmitting a broadcast video signal to a receiving terminal, a video exchange for distributing encoded video signals from the video transmitting station to the receiving terminals, and an encoded video signal received from the video exchange. In a video distribution system composed of a plurality of receiving terminals for decoding and displaying, the receiving terminal sends to the video exchange a video selection switching request signal for requesting selective switching of encoded video signals to be transmitted to the terminal. The video exchange includes a video selection requesting means for transmitting, and the video exchange has a guidance screen registration means for registering a video information guidance screen in which the intra-frame encoding processing is performed on the broadcast video transmitted from each video transmission station, and the video selection from the receiving terminal. Intra-frame coding request means for receiving the switching request signal and transmitting the intra-frame coding request to the video transmitting station, and for receiving the video selection switching request signal from the receiving terminal. If so, the transmission video is switched so as to transmit the video information screen registered in the guide screen registration unit related to the broadcast video of the specified video transmission station, and the video exchange transmits the video in accordance with the instruction of the intra-frame encoding requesting means. After the intra-frame coding of the coded video signal is detected, a transmission video selection means is provided for controlling the coded video signal from the video transmission station to be transmitted to the receiving terminal. It is provided with an intraframe coding control means for receiving an intraframe coding request from the exchange and for instructing the intraframe coding to the coding means for high efficiency coding of the video signal from the video source. Characteristic video exchange distribution system. 2. A plurality of video transmitting stations for transmitting a broadcast video signal to a receiving terminal, a video exchange for distributing encoded video signals from the video transmitting station to the receiving terminals, and an encoded video signal received from the video exchange. In a video distribution system composed of a plurality of receiving terminals for decoding and displaying, the receiving terminal sends to the video exchange a video selection switching request signal for requesting selective switching of encoded video signals to be transmitted to the terminal. The video exchange includes a video selection requesting means for transmitting, and the video exchange has a guidance screen registration means for registering a video information guidance screen in which the intra-frame encoding processing is performed on the broadcast video transmitted from each video transmission station, and the video selection from the receiving terminal. When a switching request signal is received, a delay intra-frame coding requesting means for transmitting an intra-frame coding request to the video transmitting station after a lapse of a predetermined fixed time, and a receiving end. When the video selection switching request signal is received, the transmission video is switched so as to transmit the video information screen registered in the guide screen registration section regarding the broadcast video of the specified video transmission station, and the intra-frame encoding is performed. Transmission video selection means for controlling to transmit the encoded video signal from the video transmission station to the receiving terminal after the intra-frame encoding of the encoded video signal transmitted from the video exchange is detected by the instruction of the requesting means. The video transmitting station receives an intra-frame encoding request from the video exchange and issues an intra-frame encoding instruction to the encoding means for performing high-efficiency encoding of the video signal from the video source. A video exchange / distribution system comprising encoding control means. 3. A plurality of video transmitting stations for transmitting a broadcast video signal to a receiving terminal, a video exchange for distributing coded video signals from the video transmitting station to the receiving terminals, and a coded video signal received from the video exchange. In a video distribution system composed of a plurality of receiving terminals for decoding and displaying, the receiving terminal sends to the video exchange a video selection switching request signal for requesting selective switching of encoded video signals to be transmitted to the terminal. The video exchange includes a video selection requesting means for transmitting, and the video exchange has a guidance screen registration means for registering a video information guidance screen in which the intra-frame encoding processing is performed on the broadcast video transmitted from each video transmission station, and the video selection from the receiving terminal. Intra-frame coding request means for receiving the switching request signal and transmitting the intra-frame coding request to the video transmitting station, and for receiving the video selection switching request signal from the receiving terminal. If so, the transmission video is switched so as to transmit the video information screen registered in the guide screen registration unit related to the broadcast video of the specified video transmission station, and the video exchange transmits the video in accordance with the instruction of the intra-frame encoding requesting means. After the intra-frame coding of the coded video signal is detected, a transmission video selection means is provided for controlling the coded video signal from the video transmission station to be transmitted to the receiving terminal. When an intra-frame coding request from the exchange is received, a delay frame for instructing the intra-frame coding to the coding means for high-efficiency coding of the video signal from the video source after a lapse of a predetermined fixed time. An image exchange / distribution system characterized by comprising an inner coding control means. 4. A plurality of video transmitting stations for transmitting a broadcast video signal to a receiving terminal, a video exchange for distributing encoded video signals from the video transmitting station to the receiving terminals, and an encoded video signal received from the video exchange. In a video distribution system composed of a plurality of receiving terminals for decoding and displaying, the receiving terminal sends a guide screen request signal for requesting to transmit the video information screen information registered in the guide screen registration means of the video exchange. The video exchange includes guide screen requesting means for instructing the video exchange, and the video exchange registers the guide screen registration means for registering the video information guide screen in which the intra-frame encoding processing is performed on the broadcast video transmitted from each video transmitting station, and the receiving terminal. And a guide screen from the receiving terminal, which receives the guide screen cancellation request signal and transmits an intraframe coding request to the video transmitting station. When the request signal is received, the transmission video is switched so as to transmit the video information screen registered in the guide screen registration unit regarding the broadcast video of the designated video transmission station, and the intra-frame encoding requesting means instructs the video information screen. After the intra-frame coding of the coded video signal transmitted from the video exchange is detected, a transmission video selection means is provided for controlling the coded video signal from the video transmission station to be transmitted to the receiving terminal. The station receives an intra-frame encoding request from the video exchange and provides an intra-frame encoding control means for instructing the intra-frame encoding to the encoding means for performing high-efficiency encoding of the video signal from the video source. A video exchange and distribution system characterized by being equipped. 5. A multipoint multipoint conferencing system comprising a plurality of videoconferencing terminals installed at remote multipoints and a multipoint multipoint videoconferencing control device for controlling the videoconference by connecting these videoconferencing terminals. In the video conferencing system, the multipoint video conferencing control device newly selects an initial screen registration means for registering an intra-frame-encoded video information initial screen for each video conferencing terminal and a source terminal switching request. Frame encoding requesting means for transmitting an intraframe encoding request to the selected source videoconference terminal, and the initial screen registration unit for the source videoconference terminal newly selected when the source terminal switching request is generated. The video information screen registered in the above is switched so as to be transmitted, and the transmission source video conference terminal is in accordance with the instruction of the intra-frame encoding requesting means. A television that transmits and receives a video signal is provided with a transmission video selection unit that controls the transmission of the encoded video signal from the transmission source video conference terminal after the intra-frame encoding of the encoded video signal transmitted from the video signal is detected. The conference terminal receives an intra-frame encoding request from the multipoint video conference control device and instructs the encoding means that performs high-efficiency encoding of the video signal from the video source to perform intra-frame encoding. A multipoint videoconferencing system comprising an intra-encoding control means. 6. A multipoint multipoint conferencing system comprising a plurality of videoconferencing terminals installed at remote multipoints and a multipoint multipoint videoconferencing control device for controlling the videoconference by connecting these videoconferencing terminals. In the video conference system, the multipoint video conference control device has an initial screen registration means for registering an intra-frame-encoded video information initial screen for each video conference terminal, and a predetermined time when a source terminal switching request is issued. Delayed intra-frame coding request means for transmitting an intra-frame coding request to a newly selected transmission source video conference terminal after a lapse of time, and a transmission source TV newly selected when a switching request of the transmission source terminal occurs The video information screen registered in the initial screen registration unit for the conference terminal was switched to be transmitted, and the instruction of the intra-frame encoding requesting means was made. Therefore, a transmission video selection means is provided for controlling the transmission of the encoded video signal from the transmission source video conference terminal after the intra-frame encoding of the encoded video signal transmitted from the transmission source video conference terminal is detected. The video conferencing terminal that transmits and receives the video signal receives an intra-frame encoding request from the multi-point video conferencing control device and performs intra-frame encoding to the encoding means that performs high-efficiency encoding of the video signal from the video source. A multipoint video conference system comprising an intraframe coding control means for instructing coding. 7. An inter-multipoint videoconferencing system comprising a plurality of teleconferencing terminals installed at remote multipoints and an inter-multipoint videoconferencing control device connecting the videoconferencing terminals to control the videoconference. In the video conferencing system, the multipoint video conferencing control device newly selects an initial screen registration means for registering an intra-frame-encoded video information initial screen for each video conferencing terminal and a source terminal switching request. Frame encoding requesting means for transmitting an intraframe encoding request to the selected source videoconference terminal, and the initial screen registration unit for the source videoconference terminal newly selected when the source terminal switching request is generated. The video information screen registered in the above is switched so as to be transmitted, and the transmission source video conference terminal is in accordance with the instruction of the intra-frame encoding requesting means. A television that transmits and receives a video signal is provided with a transmission video selection unit that controls the transmission of the encoded video signal from the transmission source video conference terminal after the intra-frame encoding of the encoded video signal transmitted from the video signal is detected. The conference terminal receives an intra-frame coding request from the multipoint video conference control device and, after a predetermined time has elapsed, performs intra-frame coding on a coding means for performing high-efficiency coding of a video signal from a video source. An inter-point video conference system comprising an intra-frame encoding control means for instructing encoding. 8. A multipoint multipoint conferencing system comprising a plurality of videoconferencing terminals installed at remote multipoints and a multipoint multipoint videoconferencing control device for connecting the videoconferencing terminals to control a videoconference. In the video conference system, the multipoint video conference control device includes an initial screen registration means for registering an intra-frame encoded video information initial screen for each video conference terminal, and an initial screen cancellation request signal from the receiving video conference terminal. Intra-frame encoding requesting means for receiving and transmitting an intra-frame encoding request to the source video conference terminal, and the specified source video conference when the initial screen request signal from the receiving video conference terminal is received. Switching to transmit the video information screen registered in the initial screen registration unit relating to the terminal, and instruction of the intra-frame encoding request means. Therefore, it is provided with a transmission video selection means for controlling to transmit the encoded video signal from the transmission source video conference terminal after the intra-frame encoding of the encoded video signal transmitted from the transmission source video conference terminal is detected, A video conference terminal for transmitting and receiving a video signal includes initial screen requesting means for transmitting a transmission request or cancellation request to an initial screen registration means of the multipoint videoconference control device, and intra-frame encoding from the multipoint videoconference control device. A multipoint-to-point television comprising an intraframe coding control means for instructing intraframe coding to a coding means for receiving a request and performing high efficiency coding of a video signal from a video source. Conference system.