JPH1032638A - Video conference system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the video conference system which transits to the privacy mode without a sense of incongruity and addition of a special function by taking notice of a noise elimination function so as to utilize it effectively. SOLUTION: The equipment is provided with a privacy mode switch used to set when conversation of its own terminal equipment is desired not to be heard by an opposite terminal equipment in the video conference, a noise elimination means (DSP circuit 3) which cuts off an input voice as noise when a voice level received from a microphone 1 is a preset level or below, and a control means (DSP3, control section 9) which detects it when the privacy mode is set by the privacy mode switch 8 to set higher a voice level setting value of the noise elimination means than that in the usual state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video conference apparatus, and more particularly to a voice control of a video conference apparatus having a confidential mode function that is set when a conversation on the own terminal side is not desired to be heard by the other terminal side during the video conference. It is about technology.

[0002]

2. Description of the Related Art Some video conference apparatuses are provided with a function of a confidential mode for a case where a partner who is in a communication conference does not want to be heard locally. This is generally done by turning on a switch that is used as a trigger when a confidential conversation is desired, thereby completely cutting off the microphone input voice to be transmitted while leaving the video as it is.

Japanese Patent Laid-Open Publication No. Hei 3-120944 discloses that the other party knows that the mode is the secret mode by cutting off the microphone input voice during the secret mode and transmitting a prepared image to the other party. There is disclosed a video conferencing apparatus capable of performing such operations.

On the other hand, in a video conference apparatus, a voice input from a microphone or the like is used to determine the noise below a certain value as noise instead of significant voice by using the voice level and voice energy (root mean square of voice level). Some have a function of removing noise. Further, there is an apparatus having an echo canceling function for producing a pseudo echo signal by performing an appropriate filter operation on a received and output audio signal and subtracting the same from a transmission audio signal input from a microphone to thereby remove echo. . in recent years,
DSP (Digital Signal Procedures)
(sor: digital signal processing device), many of which realize these noise removing functions and echo canceling functions in a software-programmable manner.

[0005]

However, in such a conventional video conference apparatus, the sound is completely cut off in the secret mode, so that the other party suddenly stops producing any sound, and Is unnatural, rude, and impractical. Even if a preset image is transmitted as described in Japanese Patent Application Laid-Open No. 3-120944, the above problem is not solved much, and additional hardware and software are required.

Next, regarding the problem of the echo canceller,
The echo canceller must successively update the coefficients of the filter operation for generating the pseudo echo in response to the environmental change in the conference room (sound field). However, if there is a generated sound in the sound field itself during the meeting, there is a problem that updating of the coefficient becomes inaccurate.

Therefore, the present invention has been made to solve such a problem, and by using a noise removal function effectively and paying attention to it, without adding a special function, and It is an object of the present invention to provide a video conference apparatus capable of shifting to a secret mode without discomfort.

In addition, attention is paid to the fact that confidential speech generally has a lower voice level than ordinary conversation, that is, a lower voice level (voice energy), and the coefficient of the echo canceller can be updated more accurately. It is intended to provide a video conference device.

[0009]

In order to achieve the above-mentioned object, the invention according to claim 1 of the present application provides a secret story which is set when a conversation on the own terminal side is not desired to be heard by the partner terminal side during a video conference. A mode setting unit, a noise removal unit that cuts the input voice as noise when the audio level input from the microphone is equal to or less than a preset value, and a secret mode is set by the secret mode setting unit. A control means for detecting this and setting a sound level set value of the noise removing means to be larger than usual.

[0010] Further, the invention according to claim 2 similarly provides:
A secrecy mode setting means that is set when the other terminal does not want to hear the conversation of the own terminal side during the video conference, and when the sound energy input from the microphone is equal to or less than a preset value, the input sound is regarded as noise. And a control means for detecting when the secret mode is set by the secret mode setting means, and setting the voice energy setting value of the noise removing means to be larger than usual. Things.

[0011] On the other hand, the invention according to claim 3 is a secret mode setting means for setting when the other terminal does not want to hear the conversation of the terminal during the video conference, and generating a pseudo echo signal from the received voice signal. And an echo canceller that removes echoes contained in the transmission audio signal by subtracting it from the input audio signal, and performs training for updating coefficients necessary for generating a pseudo echo signal from the reception audio signal. And a control means for detecting when the secret mode is set by the secret mode setting means, and performing training for updating the coefficient of the echo canceller.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of a video conference apparatus according to each invention of the present application. Here, only a main part (audio processing system) according to the invention is shown.

In the figure, 1 is a microphone, 2 is a microphone 1
This is an A / D converter which samples an analog audio signal input from the A / D converter at a predetermined sampling frequency and A / D converts the analog audio signal into a digital audio signal.

Reference numeral 3 denotes a DSP circuit (digital signal processing circuit) capable of performing various digital processing by software on an input digital signal to realize various processing functions. And a noise canceling function (echo canceller) for the digital audio signal. 4 is a DSP circuit similar to the above, and this DSP circuit 4 is a voice CODEC (codec).
In this case, encoding of transmission audio data output from the DSP circuit 3 and decoding of the received encoded audio data are performed. Each of the DSP circuits 3 and 4 has a built-in ROM and RAM as its peripheral devices.

Reference numeral 5 denotes a communication control device which is connected to a communication line such as ISDN and controls various protocols related to video conference communication.

Reference numeral 6 denotes that the received voice data is the voice COD.
This is a D / A converter that D / A converts a digital audio signal decoded and output by the EC DSP circuit 4 and outputs the obtained analog audio signal to the speaker 7. Note that the received digital audio signal output from the DSP circuit 4 is input to another DSP circuit 3 and is used in its echo canceling function.

Reference numeral 8 denotes a privacy mode switch (security mode setting means), and 9 detects the state of the privacy mode switch 8 and controls each of the DSP circuits 3 and 4, the communication control device 5, and further, each unit of the device not shown. Control unit, C
It consists of PU, ROM, RAM and the like.

Next, the operation of the video conference apparatus configured as described above will be described.

First, the operation according to the embodiment of the present invention will be described with reference to the flowchart shown in FIG. Note that this embodiment is a case where noise removal is performed according to the audio level.

The controller 9 monitors the state of the privacy mode switch 8 (decision 101), and if the switch is off, that is, if the privacy mode is not set, the DSP circuit 3
(No in decision 101) and the secret mode switch 8
Is turned on, that is, when the secret mode is set, the DSP circuit 3 is notified that the mode is the secret mode (Y in decision 101).
es).

In the audio processing system, audio is taken in from the microphone 1 and converted into digital data by the A / D converter 2.
Transfer to the DSP circuit 3.

The DSP circuit 3 changes the audio level setting value regarded as noise in the noise removal function depending on whether or not the secret mode has been set by the control unit 9. That is, in the confidential mode, the voice level setting value is increased so that voices of a certain level or more, that is, voices other than non-confidential levels are regarded as noise (Yes in determination 101 → process 103). If the mode is not the secret mode, a normal voice level value is set (decision 10).
No. 1 → Process 102).

Here, an example of the value is shown. For example, it is assumed that the audio level has 256 levels and the audio level of a normal conversation is 128. In the normal mode, 32 or less is regarded as noise. In the secret mode, 130 or less including the voice level (128) of the ordinary conversation is regarded as noise.

Based on the above, noise removal processing is performed to cut the lower sound as noise. The audio data output from the DSP circuit 3 is subjected to a predetermined encoding process by the next DSP circuit 4, sent out to the line via the communication control device 5, and sent to the other party's video conference device.

As described above, according to the present embodiment, by using the noise elimination function that uses the threshold value regarded as noise as the level of the audio signal and by changing the audio level setting value of the noise elimination in a programmable manner, the secret story can be obtained. Since it is cut as noise, the sense of incongruity in the secret mode can be eliminated. Also, by changing the reference value of the noise removal function, the reference value is also used for the secret talk function, so that hardware and software for the secret talk function can be reduced.

Next, the operation according to the embodiment of the present invention will be described with reference to the flowchart shown in FIG.

In a video conference apparatus, the noise removal function may be performed based on the energy value of voice. Here, the energy value of the sound is a root mean square of the level of the sound signal. This embodiment is a case where the reference value of the noise removal function in the above embodiment is not an audio level but an audio energy value.

That is, similarly to the above embodiment, the control unit 9
Monitors the state of the secret mode switch 8 (determination 20).
1) If the secret mode is not set when the switch is turned off, the fact is notified to the DSP circuit 3 (N in decision 201).
o) When the confidential mode is set by turning on the confidential mode switch 8, the DSP circuit 3 is notified that the confidential mode is set (Yes in decision 201).

In the audio processing system, audio is taken in from the microphone 1 and converted into digital data by the A / D converter 2.
Transfer to the DSP circuit 3.

The DSP circuit 3 changes the voice energy setting value regarded as noise in the noise removal function according to the presence or absence of the setting of the secret mode notified from the control unit 9. That is, in the privacy mode, the voice energy setting value is increased, and the voice whose input voice energy is larger than a certain level, that is, the voice other than the voice having the energy value which is not the privacy is set to be regarded as noise (Yes in decision 201)
→ Process 203). If the mode is not the confidential mode, a normal voice energy value is set (No in decision 201 → process 202).

Here, an example of the value is shown. For example, it is assumed that the voice energy has 256 levels and the voice energy value of a normal conversation is 128. In the normal mode, 32 or less is regarded as noise. Then, in the secret talk mode, 130 or less including the voice energy value (128) of normal conversation is regarded as noise.

Based on the above, noise removal processing is performed to cut the lower sound as noise. The audio data output from the DSP circuit 3 is transmitted to the next D
A predetermined encoding process is performed by the SP circuit 4, sent out to the line via the communication control device 5, and sent to the other party's video conference device.

As described above, according to the present embodiment, by using the noise elimination function that uses the threshold value regarded as noise as the energy value of the audio signal and changing the audio energy setting value of the noise elimination in a programmable manner, the secret story can be obtained. Is cut as noise, so that the sense of incongruity in the secret mode can be eliminated. Also, by changing the reference value of the noise removal function, the reference value is also used for the secret talk function, so that hardware and software for the secret talk function can be reduced.

Next, the operation according to the embodiment of the present invention will be described with reference to the flowchart shown in FIG.

First, the operation of the echo canceller will be described.
A brief description will be given. The echo canceller generates a pseudo echo signal by performing a predetermined filter operation on the audio signal received and output into the conference room, and performs echo removal by subtracting the pseudo echo signal from the input audio signal.

The principle is that, for example, in the case of 8 kHz sampling, when performing echo cancellation for 0.1 second (echo reverberation time), 800 coefficients are prepared for 800 samples, and 8 coefficients are obtained for 1 sample (for 125 μs).
Basically, a 00-order product-sum operation is performed.

Here, a coefficient of 800 is required. This is based on the fact that no sound is generated in the reproduced sound field and only echo of the output sound is input, and the coefficient is calculated from the output sound by the coefficient. It is desirable that the sound be silenced when the pseudo echo is subtracted from the input sound.

Therefore, when the input voice is below a certain level,
The coefficient is sequentially updated on the assumption that no sound is generated in the sound field. In this embodiment, when the secret mode switch 8 is set to ON, the secret, that is, the sound generated in the sound field is It is considered to be very small and suitable for echo canceller coefficient updating, and at this time, coefficient updating is performed.

That is, the control section 9 monitors the state of the privacy mode switch 8 (No loop of the determination 301), and when the privacy mode switch 8 is turned on and the privacy mode is set, it is notified that the privacy mode is set. Notify the DSP circuit 3,
Causes the DSP circuit 3 to perform a training process for updating the echo canceller coefficient (Yes in decision 301 → process 3)
02).

As described above, in the present embodiment, since the voice generated in the conference room is considered to be very low during the secret mode, the training for updating the echo removal coefficient required for the echo canceller is performed. Performing this operation during the operation of the secret talk function can improve the accuracy of updating the coefficient.

[0042]

As described above, according to the first aspect of the present invention, a confidential mode setting means for setting when the other terminal does not want to hear the conversation of the own terminal during the video conference, and the microphone When the voice level input from is less than or equal to a preset value, a noise removal unit that cuts the input voice as noise, and when a secret mode is set by the secret mode setting unit, this is detected, Control means for setting a voice level setting value of the noise removing means to be larger than usual; realizing a confidential mode by effectively utilizing a noise removing function and changing the voice level setting value of the noise removal. Thus, there is an effect that the mode can be shifted to the secret mode without adding a special function and without a sense of incongruity.

According to the second aspect of the present invention, similarly, a secret mode setting means for setting when the other terminal does not want to listen to the conversation of the own terminal side during the video conference, and is input from the microphone. A noise removal unit that cuts the input voice as noise when the voice energy is equal to or less than a predetermined value; and detects when the secret mode is set by the secret mode setting unit and detects the noise. Control means for setting the voice energy set value of the normal mode to a value larger than the normal time, and by effectively utilizing the noise removal function and changing the voice energy set value of the noise removal to realize a secret mode, There is an effect that the mode can be shifted to the secret mode without adding a special function and without a sense of incompatibility.

On the other hand, according to the third aspect of the present invention, a confidential mode setting means for setting when a conversation on the own terminal side is not desired to be heard by the other terminal side during the video conference, and a pseudo echo signal from the received voice signal. An echo canceller that removes echoes contained in a transmission audio signal by generating and subtracting from an input audio signal, and performs training for updating coefficients necessary for generating a pseudo echo signal from a reception audio signal. And a control means for detecting when a secret mode is set by the secret mode setting means and performing training for updating the coefficient of the echo canceller. Assuming that the voice is small, updating the echo canceller coefficients at this time can provide more accurate coefficient updates. A.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a main part of an embodiment of a video conference apparatus according to each invention of the present application.

FIG. 2 is a flowchart showing an operation according to the embodiment of the invention described in claim 1;

FIG. 3 is a flowchart showing an operation according to the embodiment of the invention described in claim 2;

FIG. 4 is a flowchart showing an operation according to the embodiment of the invention described in claim 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Microphone 2 A / D converter 3, 4 DSP circuit 5 Communication control device 6 D / A converter 7 Speaker 8 Secret mode switch 9 Control part

Claims (3)

[Claims] 1. A confidential mode setting means for setting when the other terminal does not want to listen to the conversation of the own terminal during the video conference, and when the sound level input from the microphone is equal to or less than a predetermined value, the input is performed. A noise removing unit that cuts off the voice by regarding the voice as noise; and a control for detecting when the secret mode is set by the secret mode setting unit, and setting the voice level setting value of the noise removing unit to be larger than usual. And a video conference device. 2. A confidential mode setting means for setting when the other terminal does not want to listen to the conversation of the terminal during the video conference, and inputting when the sound energy input from the microphone is equal to or less than a predetermined value. A noise removing unit that cuts off a voice by regarding the voice as noise; and a control that, when the secret mode is set by the secret mode setting unit, detects the noise mode and sets a voice energy setting value of the noise removing unit to be larger than usual. And a video conference device. 3. A confidential mode setting means for setting when the other terminal does not want to hear the conversation of the terminal during the video conference, and generating a pseudo echo signal from the received voice signal and subtracting it from the input voice signal. An echo canceller that removes the echo included in the transmission voice signal and performs training for updating a coefficient necessary for a calculation for generating a pseudo echo signal from the reception voice signal, and a privacy mode in the privacy mode setting means. And a control means for detecting when is set and performing training for updating the coefficient of the echo canceller.