JP3512828B2 - Video conference system - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video conference system capable of automatically adjusting a volume level during transmission. 2. Description of the Related Art In recent years, a video conference system uses a display device or the like to provide visual information such as characters and figures in real time with a remote party in addition to voice communication means used in conventional telephones. It has been developed as an exchangeable means. At CCITT, video coding and multiplexing systems and communication procedures for audiovisual services have been officially recommended, and with the expansion of corporate activities and the spread of digital communication networks, CCITT
Video conference systems, video TV phones, and the like that comply with the ITT recommendations have been developed. Hereinafter, a conventional video conference system will be described with reference to the drawings. FIG. 3 is a functional block diagram of a conventional video conference system. In FIG. 3, reference numeral 1 denotes a monitor for displaying an image from the other party or a self-portrait, 2 a display control unit for controlling switching of image display on the monitor 1, 3 a video camera for capturing a video, and 4 a video camera. A video camera controller 3 for focusing and angle adjustment 3; a scanner 5 for reading a still image; 6 an image codec for encoding / decoding images captured by the video camera 3 and the scanner 5; A microphone for audio output; 8 a speaker for audio output; 9 an audio codec unit for encoding / decoding audio; 10 a coordinate input unit for operating the magnification and angle of the video camera 3 and performing telewriting; 11 is a telewriting control unit for processing coordinate information from the coordinate input unit 10, 12 is a keyboard for inputting telephone numbers and selecting functions,
Reference numeral 3 denotes a terminal control unit that controls the entire terminal such as data input / output processing between units, and 14 denotes image, audio, and telewriting data according to CCITT Recommendation H.3 A multiplexing / separating unit for multiplexing in a frame format of H.221 (a frame structure of 64 Kbit / s channel in audiovisual teleservice), and for demultiplexing a frame sent from the other party into image and audio telewriting data;
CITT Recommendation H. A BAS (Bitrate Allocation Signal) control unit that executes a communication procedure based on H.242 (a method for setting up communication between audiovisual terminals using digital channels up to 1920 Kbit / s), and 16 connects the terminal to the ISDN line 18 A line interface 17 for managing calls such as incoming and outgoing calls and disconnections, and 18 an ISDN line as a transmission line. [0004] The operation of the conventional video conference system configured as described above will be described below. When the telephone number of the remote terminal is set from the keyboard 12 and the call key is pressed, the terminal control unit 13 notifies the call control processing unit 17, and the call control processing unit 17 communicates with the remote terminal via the line interface 16. Between the B channels.
After the connection is completed, the BAS control unit 15 uses the B channel to transmit H.264. The mode setting based on 242 is performed, and data transmission / reception is started. When transmitting a moving image from the own terminal to the other terminal, the image data recorded by the moving image camera 3 is directly displayed on the monitor 1 of the own device, and the image codec unit 6 uses the moving image compression standard. Some C
CITT Recommendation H. 261 is applied. The still image read by the scanner 5 is subjected to the same processing as the moving image,
According to the mode of the BAS control unit 15, the data is transmitted to the ISDN line 18 via the line interface 16 and transmitted to the partner terminal. The other terminal expands and decodes the received compressed and coded data in the image codec unit 6, and displays an image on the monitor 1 via the display control unit 2 if the image is an image.
When transmitting the voice from the local terminal to the other terminal, the voice codec unit 9 applies the CCITT Recommendation G.10 to the voice data at the volume level input from the microphone 7.
722 or G. 728, and performs coding according to IS
The data is transmitted to the partner terminal via the DN line 18. However, in the above-described conventional video conference system, since the volume of the transmitted voice is fixed, it is possible to cope with a change in the position of the transmitter with respect to the microphone and a change in the volume of the uttered voice. If the speaker is close to the microphone, the volume is too high, and if the speaker is far from the microphone, the volume is too low. Had problems. An object of the present invention is to solve the above-mentioned problem and to provide a video conference system which can automatically change the transmission volume so as to be constant. [0007] In order to achieve the above object, the present invention adds a volume level detection unit and a volume level control unit to the conventional configuration, and provides a focus obtained by a moving image camera control unit. Estimate the speaker's volume level from the distance information and notify the volume level control unit of the initial value of the volume level, and when the transmission starts, the volume level data of the audio data input from the microphone in the volume level control unit the modifications added, if the focal length information from the change in Therefore video camera control unit of the position of the talker is changed is obtained to carry out the change of the volume level setting value at the volume level control unit. The volume level detection unit uses a preset volume level as a threshold, calculates the maximum value of the volume level within a certain period of time from the volume level value obtained for each sampling, compares it with the threshold, and The level control unit transmits a transmission voice based on the volume level estimated from the position of the speaker obtained from the focal length information in the video camera control unit and the comparison result actually obtained by the volume level detection unit. The voice level of the person is automatically adjusted at regular intervals. According to the present invention, with the above-described configuration, the approximate volume level of a sender is estimated from the position of the sender determined from the focal length information given from the moving image camera control unit, and the estimated level is input from the microphone. The actual volume level of the speaker to be transmitted is compared with a predetermined set value, and if the actual volume level is lower than the set value, the set value is increased, and if the actual volume level is higher than the set value, the set value is increased. , The volume level to be transmitted can be automatically adjusted to be constant. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a functional block diagram of a video conference system according to an embodiment of the present invention, in which a volume level detection unit 19 and a volume level control unit 20 are added to the configuration of the conventional example shown in FIG. That is, in FIG. 1, reference numeral 1 denotes a monitor for displaying an image from the other party or a self-portrait, 2 a display control unit for performing switching control of image display on the monitor 1, 3 a video camera for capturing a video, and 4 a video camera. A video camera controller for adjusting the focus and angle of the camera 3, a scanner 5 for reading a still image, 6 an image codec for encoding / decoding images captured by the video camera 3 and the scanner 5, and a voice 7 An input microphone, 8 is a speaker for audio output, 9 is an audio codec unit for encoding / decoding audio, and 10 is a coordinate input unit for operating the magnification and angle of the video camera 3 and performing telewriting. , 11 are telewriting control units for processing coordinate information from the coordinate input unit 10, and 12 are keys for inputting telephone numbers and selecting functions. Over de, 13 terminal control unit that controls the entire terminal, such as data input and output processing between each section, 14 image, audio, tele-writing data CCITT Recommendation H. 221 (64 Kbit / s for audiovisual teleservices)
A multiplexing / separating unit for multiplexing in the frame format of the s channel (frame structure of the s channel) and for demultiplexing the image and audio telewriting data from the frame transmitted from the partner terminal. 242 (192
BAS (Bitrate Allocat) that executes a communication procedure based on a method for setting up communication between audiovisual terminals using digital channels up to 0 Kbit / s.
ionSignal) control unit, 16 is a line interface for connecting a terminal to the ISDN line 18, 17 is an incoming / outgoing call,
A call control processor 18 for managing calls such as disconnection is an ISDN line as a transmission path. Reference numeral 19 denotes a volume level detection unit which compares the volume level set value with the amplitude of the voice detected by the voice codec unit 9 to determine the volume level.
Reference numeral denotes a sound volume level control unit for relatively adjusting the data of the amplitude part in the audio data based on the position of the sender obtained from the focal length information in the video camera control unit 4 and the comparison result from the sound volume level detection unit 19. . The operation of the video conference system according to the present embodiment configured as described above will be described below. When the telephone number of the other terminal is set from the keyboard 12 and the call key is pressed, the terminal control unit 13
And the call control processing unit 17
The connection of the B channel is performed with the terminal on the other end through the terminal. After the connection is completed, the BAS control unit 1 uses the B channel.
According to H.5. 242 based on the mode setting,
Data transmission / reception is started. When transmitting a moving image from the own terminal to the other terminal, the image data recorded by the moving image camera 3 is directly displayed on the monitor 1 of the own device, and the image codec unit 6 uses the moving image compression standard. Certain CCITT Recommendation H. 261 and perform encoding according to
According to the mode of the AS control unit 15, the line interface 1
6 to the ISDN line 18 and to the destination terminal. In the other terminal, the received compression-encoded data is decoded by the image codec unit 6. A still image read by the scanner 5 is subjected to the same processing as a moving image, and if it is an image, the still image is displayed on the monitor 1 via the display control unit 2. Next, a case where voice is transmitted from the local terminal to the remote terminal will be described with reference to a volume level transition chart shown in FIG. First, after activation, the position of the speaker is confirmed from the focal length information obtained by the video camera controller 4, the volume level of the speaker is estimated, and the initial value of the volume level is notified to the volume level controller 20. (Section A). When the transmission is started, the volume level control unit 20 corrects the data of the amplitude portion of the voice data input from the microphone 7. In other words, the peak of the volume level is detected by the volume level detection unit 19 at regular intervals (tx),
If the actually obtained volume level is smaller than the peak value of the volume level set in advance as a reference, the volume level set value previously set from the focal length information is increased (section B), and conversely. If the volume level actually obtained is high, the volume level set value in the volume level control unit 20 is reduced (section C). Next, when it is determined from the focal length information obtained from the moving image camera controller 4 that the position of the speaker has changed, the volume level set value is similarly changed in the volume level controller 20 (section). D). The audio data after the volume level has been modified is encoded by the audio codec unit 9 and multiplexed by the multiplexing / demultiplexing unit 14 in the same manner as in the conventional example, and then the video data is processed. Similarly, it is transmitted to the partner terminal via the ISDN line 18. In the case of reception, the audio coded data received from the partner terminal is decoded by the audio codec 9 and output to the speaker 8. As described above, according to the present invention, the sound volume level is determined by comparing a predetermined sound volume level setting value with the amplitude of the sound detected from the sound codec unit. A level detector, and a volume level controller that adjusts the volume level set value at regular intervals based on the position of the speaker obtained from the focal length information in the video camera controller and the comparison result in the volume level detector. Estimating the speaker's volume level from the focal length information obtained by the video camera control unit and notifying the volume level control unit of the initial value of the volume level, and when the transmission is started, the volume level control unit the data to modify the amplitude portion of the input voice data added, the volume Les If the focal length information from thus moving the camera control unit to change the position of the talker is changed Since the volume level set value is changed in the bell control unit, a change in the volume of the speaker can be reliably detected, and the volume level can be reduced before performing data compression after analog-digital conversion. Since the adjustment is performed, the transmission volume level can be automatically adjusted with a simple configuration without depending on each audio coding method.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a functional block diagram of a video conference system according to an embodiment of the present invention. FIG. 2 is a time chart showing a transition of a sound volume level in one embodiment of the present invention. FIG. 3 is a functional block diagram of a conventional video conference system. [Description of Signs] 1 monitor 2 display control unit 3 video camera 4 video camera control unit 5 scanner 6 image codec unit 7 microphone 8 speaker 9 audio codec unit 10 coordinate input unit 11 telewriting control unit 12 keyboard 13 terminal control unit 14 multiplexing Separation / separation unit 15 BAS control unit 16 Line interface 17 Call control processing unit 18 ISDN line 19 Volume level detection unit 20 Volume level control unit

Claims (1)

(57) [Claim 1] In a video conference system that encodes an audio signal and an image signal and transmits the encoded signal via a communication line, focus adjustment and angle adjustment of a video camera on the own side are performed. A video camera control unit; an audio codec unit that encodes audio input from a microphone; and a predetermined volume level set value and a sound amplitude detected from the audio codec unit. A volume level detection unit to be performed; and a volume level control for adjusting the volume level set value at regular intervals based on a position of a speaker obtained from focal length information in the video camera control unit and a comparison result in the volume level detection unit. And estimating the volume level of the speaker from the focal length information obtained by the video camera control unit, and Notifies the initial value of the quantity level, the data to modify the amplitude portion of the audio data inputted from the microphone in the sound volume level control section and the transmission is started addition, thus moving the camera to change the position of the talker If the focal length information from the control unit changes had row changes volume level setting value at the volume level control unit, also fixes the data of the amplitude portion, the volume level detecting unit is constant
Detect the peak of the volume level at intervals, and use it as a reference
Compare with the set volume level peak value and
If the volume level seems to be low,
The volume level set value from the
If the volume level obtained is high, set the volume level.
A video conference system characterized by lowering the fixed value .