JP3001683B2 - Multipoint communication control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multipoint communication control device for realizing a simultaneous multipoint videoconference between three or more arbitrary videoconference terminals.

[0002]

2. Description of the Related Art FIG. 5 is a block diagram showing a conventional multipoint communication control device disclosed in, for example, Japanese Patent Laid-Open No. 1-286689. In the figure, 1 is the multipoint communication control device, and 2 is a system control unit that controls and manages the whole. Reference numeral 3 denotes a line interface unit (hereinafter, referred to as a line I / F unit) that manages an interface with a line connecting each of the video conference terminals (not shown).

[0003] Reference numerals 4a to 4m denote multiplexing units for multiplexing video data, audio data, and general-purpose data to be transmitted to the respective video conference terminals into multiplexed data. A separation unit that separates the data into video data, audio data, and general-purpose data.

[0004] Reference numeral 6 designates one of the video data demultiplexed by the demultiplexing units 5a to 5m, and selects one of the video data.
, A sound control unit 7 for synthesizing the sound data separated by the separation units 5a to 5m and sending the synthesized data to the multiplexing units 4a to 4m, and 8 a general-purpose unit separated by the separation units 5a to 5m. It is a general-purpose data port control unit that controls data.

Next, the operation will be described. Among the video conference terminals connected to the line I / F unit 3 via the line, the video conference terminal (parent terminal) that intends to hold a conference sends a multi-point communication control device 1 with any video conference terminal. Indicate whether you want to hold a multipoint video conference.

When receiving the request, the system control unit 2 instructs the line I / F unit 3 to call the designated video conference terminal. When a line between each called video conference terminal and the multipoint communication control device 1 is connected, transmission and reception of multiplexed data obtained by multiplexing video data, audio data, and general-purpose data are performed. Video conference starts.

[0007] The multiplexed data transmitted from each video conference terminal is received by the line I / F unit 3 and then passed to the corresponding demultiplexing units 5a to 5m, where the video data,
The audio data and the general-purpose data are separated, and the video data is passed to the video switching unit 6, the audio data is passed to the audio control unit 7, and the general-purpose data is passed to the general-purpose data port control unit 8.

When the video switching unit 6 receives the video data from each of the separation units 5a to 5m, it selects one of them according to the instruction of the system control unit 2, and sends the selected video data to each of the synthesizing units 4a to 4m. To deliver. The video data distributed at this time has an error correction frame configuration in which 1-bit frame pattern bits S _{1 to} Sn are added to the head of the video information as shown in FIG.

Here, the frame pattern bits S ₁ to
Sn is the value determined on the basis of a certain regularity in each multiplexing unit 4A～4m, separation unit 5A to 5M, and the video conference terminal is the frame pattern bit S ₁ to Sn
We monitor the regularity of

As a result, if the frame pattern bits S _{1 to} Sn of the received video data do not conform to the above rules, it is determined that the video data is erroneous, and the error correction frame synchronization of the video data is temporarily removed. After that, synchronization is re-established from the beginning.

When the video switching unit 6 receives video data from each of the separation units 5a to 5m, it receives the frame pattern bit S
The selection and switching of the video data are collectively performed while _{1 to} Sn are added.

Here, although the order of the frame pattern bits S _{1 to} Sn is the same in each video data, they are not temporally synchronized as shown in FIG. Therefore, the regularity of the frame pattern bits S _{1 to} Sn of the video data may be lost due to the selection / switching by the video switching unit 6. In such a case, re-establishment of the error correction frame synchronization of the video data is performed. Is required.

In the image control unit 7, each of the separation units 5a to 5
m, synthesizes all the audio data sent from m, and then generates audio data obtained by subtracting its own audio from the synthesized audio data and sends it to the multiplexing units 4a to 4m.

Similarly, the general-purpose data separated by each of the separation units 5a to 5m is sent to the general-purpose data port control unit 8 and used as control data for each video conference terminal.

[0015]

Since the conventional multipoint communication control device is configured as described above, the rule of the frame pattern bits S _{1 to} Sn is determined by the selection and switching of the video data by the video switching unit 6. When the performance is lost, it is necessary to re-establish the error correction frame synchronization of the video data each time, and there is a problem that it takes time for the video switching process.

The present invention has been made to solve the above problems, and has as its object to obtain a multipoint communication control device having a short image switching processing time.

[0017]

According to a first aspect of the present invention, there is provided a multipoint communication control apparatus which generates video data selected by a video switching unit based on a predetermined regularity.
An error correction frame control unit for multiplexing frame pattern bits is provided.

Further, the multipoint communication control apparatus according to the second aspect of the present invention extracts the video data selected by the video switching unit from the video data separated by the separation unit.
An error correction frame control unit for multiplexing frame pattern bits is provided.

[0019]

According to the first aspect of the present invention, the error correction frame control unit converts the frame pattern bits generated based on the predetermined regularity into the video data selected by the video switching unit.
By'll be replaced in the frame pattern bit, full
A multipoint communication control device that maintains the regularity of the frame pattern bit and requires a short time for the video switching process.

Further, the error correction frame control section in the invention of claim 2, the frame pattern bit extracted from the video data separated by the separating unit, the frame pattern bit video data selected by the video switching unit Multiplex
Thus , the regularity of the frame pattern bits is maintained, and a multipoint communication control device that requires a short time for video switching is realized.

[0021]

[Embodiment 1] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a main part of an embodiment of the present invention. In the figure, 4a-4
m is a multiplexing unit, 5a to 5m are demultiplexing units, and 6 is a video switching unit, which are the same as or equivalent to those in the related art denoted by the same reference numerals in FIG.

Reference numerals 9a to 9m denote error correction frame control units for generating frame pattern bits based on a predetermined regularity and replacing them with the frame pattern bits of the video data selected by the video switching unit 6. 2 shows the configuration.

In FIG. 2, reference numeral 10 denotes a frame pattern bit generation circuit for generating the frame pattern bits based on a predetermined regularity, and 11 denotes a frame pattern bit in the video data selected by the video switching unit 6. This is a 512-bit counter for extracting timing.

Next, the operation will be described. Here, the basic operation is the same as in the conventional case, and a description thereof will be omitted.

A frame panta bit generation circuit 10 built in the error correction frame control section 9a (up to 9m) generates frame pattern bits based on a predetermined regularity, and a counter 11 outputs a timing signal every 512 bits. Has occurred. This timing signal is synchronized with the timing of the frame pattern bit of the video data selected by the video switching unit 6.

The frame pattern bits added to the video data selected by the video switching unit 6 are stored in the counter 1
The frame pattern bit based on a predetermined regularity generated by the frame panta bit generation circuit 10 is inserted therein.

The frame pattern bits generated by the frame pattern bit generation circuit 10 in this way are
Pattern bit of video data selected by
Thus, the frame pattern bits of the video data sent to each video conference terminal can be made to conform to a predetermined regularity.

Embodiment 2 FIG. FIG. 3 is a block diagram showing an embodiment of the second aspect of the present invention. The same portions as those in FIG. In the figure,
Reference numeral 12 denotes a frame pattern bit extraction circuit provided in each of the separation units 5a to 5m to extract frame pattern bits of video data separated from multiplexed data from the video conference terminal.

[0029] 13a~13n the frame pattern bit extracted by this frame pattern bit extraction circuit 12, a frame of video data selected by the video switching unit 6 Pas
This is an error correction frame control unit different from that shown in FIG. 2 in that it is replaced with a tanbit .

Next, the operation will be described. Separation unit 5a
The frame pattern bit extraction circuit 12 in (（5 m)
Extract the frame pattern bits of the video data separated by the multiplexed data sent from the video conference terminal,
The corresponding error correction frame control unit 13a (~ 13
m).

The error correction frame controller 13a (to 13)
In n), the frame pattern bits of the video data selected by the video switching unit 6 are removed by the timing signal generated by the counter 11, and the frame pattern bits extracted by the frame pattern bit extraction circuit 12 are inserted therein. .

The frame pattern bits extracted from the video data separated from the multiplexed data from the respective video conference terminals by the frame pattern bit extraction circuit 12 are
By replacing the frame pattern bits with the frame pattern bits of the video data selected by the video switching unit 6, the frame pattern bits of the video data sent to each video conference terminal can be made to conform to a predetermined regularity.

[0033]

As described above, according to the present invention, a frame pattern bit generated based on a predetermined regularity or a frame pattern bit extracted from video data separated by a separation unit is sent to a video switching unit. The frame pattern bits of the selected video data are replaced so that the regularity of the frame pattern bits can be reliably maintained, synchronization is hardly lost, and the processing time for video switching is short. There is an effect that a multipoint communication control device can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a main part of a multipoint communication control apparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating a configuration of an error correction frame control unit according to the embodiment.

FIG. 3 is a block diagram illustrating a configuration of an error correction frame control unit according to an embodiment of the present invention;

FIG. 4 is a block diagram showing a conventional multipoint communication control device.

FIG. 5 is an explanatory diagram showing a transmission frame configuration of video data.

FIG. 6 is an explanatory diagram illustrating timing of video data input to a video switching unit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Multipoint communication control apparatus 4a-4m Multiplexing part 5a-5m Separation part 6 Video switching part 7 Audio control part 9a-9m Error correction frame control part 13a-13m Error correction frame control part

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04N 7/15 H04M 3/56

Claims (2)

(57) [Claims] 1. A plurality of separation units for separating multiplexed data from a video conference terminal into video data, audio data, and general-purpose data, wherein the processed video data, audio data,
And a plurality of multiplexing units for multiplexing general-purpose data into multiplexed data and transmitting the multiplexed data to the video conference terminal, and an audio switching unit for selecting one of the video data separated by the demultiplexing units and transmitting the selected video data to each of the multiplexing units And a voice control unit that synthesizes the voice data separated by each of the demultiplexing units and sends the synthesized voice data to each of the multiplexing units, thereby realizing a simultaneous multipoint video conference among three or more video conference terminals. In the multipoint communication control device, the frame data generated based on a predetermined regularity is added to the video data selected by the video switching unit.
A multipoint communication control device, comprising: an overlapping error correction frame control unit. 2. A plurality of separation units for separating multiplexed data from a video conference terminal into video data, audio data, and general-purpose data, and the processed video data, audio data,
And a plurality of multiplexing units for multiplexing general-purpose data into multiplexed data and transmitting the multiplexed data to the video conference terminal, and a video switching unit for selecting one of the video data separated by the demultiplexing units and transmitting the selected data to the multiplexing units And a voice control unit that synthesizes the voice data separated by each of the demultiplexing units and sends the synthesized voice data to each of the multiplexing units, thereby realizing a simultaneous multipoint video conference among three or more video conference terminals. In the multipoint communication control device, an error correction frame control unit that puts a frame pattern bit extracted from the video data separated by the separation unit on the video data selected by the video switching unit is provided. Multipoint communication control device.