JPH1166765A - Sound signal recording device, sound signal reproducing device and sound signal recording and reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To display information regarding the strength of a wind at the recording (image-pickup) time and to perform processing of keeping a level of a sound signal constant after processing of reducing a wind sound. SOLUTION: A detecting signal generated by a wind sound reduction processing is supplied to an amplifier in a wind sound reduction circuit 5 and also a microcomputer 9 and a gain control circuit 10. A wind sound level display part 11 is driven by the microcomputer 9 based on the detecting signal, and the information regarding the strength of the wind is displayed in real time. Then, based on the detecting signal and a signal showing the relation of size between a level of an input signal supplied separately and an AGC point, gains of sound signal gain control amplifiers 6L and 6R are controlled by the gain control circuit 10, so that regardless of the wind sound signal level, the sound signal level is kept constant. Moreover, an AAUX data including the information regarding the strength of the wind is generated by the mocrocomputer 9 based on the detecting signal. This AAUX data is recorded together with the sound signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an audio signal recording device for recording an audio signal, such as a digital VTR, an audio signal reproducing device for reproducing an audio signal, and an audio signal recording / reproducing device.

[0002]

2. Description of the Related Art For example, a digital VTR integrated with a camera
In such a recording device having a function of recording an audio signal, the audio signal that the user wants to record and reproduce is not affected by the wind noise signal caused by the wind noise or the like, or to reduce the degree thereof. A wind noise reduction circuit is provided in a stage preceding a configuration for performing processing such as encoding for generating data to be recorded on a recording medium.

The wind noise reduction circuit extracts a wind noise signal and generates a detection signal in association with the extracted wind noise signal. And
By performing gain adjustment or the like based on the detection signal, a process of reducing a wind noise signal mixed in the audio signal is performed.

[0004]

Although such a wind noise reduction process is a very effective method for recording and reproducing an audio signal satisfactorily, it has the following problems. First, at the time of recording and reproduction, the signal level of an audio signal is conventionally displayed, but information relating to the strength of wind, such as a wind sound signal level, is not displayed. Therefore, the user cannot know the wind noise signal level or the like in real time at the time of recording, and cannot confirm the conditions such as the wind sound at the time of recording at the time of reproduction.

[0005] In addition, since AGC (Auto Gain Control) processing is performed on an input signal (ie, the sum of an audio signal and a wind sound signal) prior to the wind sound reduction processing, an audio signal is generated when the wind sound signal level is large. The level is suppressed, and the wind noise signal is reduced by the subsequent wind noise reduction process. As a result, there is a portion where the audio signal level is lower than that of the preceding and following portions during reproduction, which causes a sense of discomfort in hearing. There was also.

Accordingly, an object of the present invention is to provide a function of displaying information relating to the strength of wind during recording or reproduction, or to reduce the sound signal level after wind sound reduction processing when the wind sound signal level is large. It is an object of the present invention to provide an audio signal recording device, an audio signal reproducing device, and an audio signal recording / reproducing device having a function of preventing the problem.

[0007]

According to a first aspect of the present invention, there is provided an audio signal recording apparatus for recording an audio signal, comprising a wind noise reducing means for performing a wind noise reducing process, wherein the wind noise reducing means generates the sound signal. An audio signal recording apparatus for performing processing other than wind noise reduction processing based on a detection signal.

[0008] The invention of claim 11 is an audio reproducing apparatus for reproducing an audio signal recorded on a predetermined recording medium, comprising means for separating the reproduced audio signal from the reproduced subcode data. , Based on the subcode data,
An audio signal reproducing apparatus, characterized in that reproduction time display means for displaying reproduced information is controlled so as to display information relating to wind strength.

According to a fourteenth aspect of the present invention, there is provided an audio signal recording / reproducing apparatus for recording and reproducing an audio signal, comprising a wind noise reducing means for performing a wind noise reducing process, wherein a detection signal generated by the wind noise reducing means is provided. An audio signal recording / reproducing apparatus characterized in that processing other than wind noise reduction processing is performed based on the processing.

According to the above-described invention, it is possible to perform processing other than the wind noise reduction processing using the detection signal generated in connection with the wind noise reduction processing.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is applied to a digital VTR integrally having a video camera and a liquid crystal monitor.
A configuration relating to recording of audio information according to an embodiment of the present invention will be described with reference to FIG. Note that the description of the configuration related to the video signal, such as the video camera and its image signal processing system, is omitted for simplicity. The input signals input from the left and right microphones 1L and 1R are AGC (Aut) via the micro amplifiers 1L and 1R, respectively.
o Gain Controller 3. The input signal is generally the sum of an audio signal and a wind signal. AGC3 is
The gain is adjusted to keep the signal level of the input signal constant, and the gain-adjusted signal is supplied to the A / D converter 4. The A / D converter 4 converts the supplied signal into a digital signal, and supplies the digital signal to the wind noise reduction circuit 5.

The wind noise reduction circuit 5 reduces a wind noise signal component from the supplied signal and supplies the signal to the audio signal gain adjustment amplifiers 6L and 6R. Further, the wind noise reduction circuit 5 generates a detection signal in connection with the process of reducing the wind noise signal component, and supplies the detection signal to the audio signal gain adjustment amplifiers 6L and 6R and the microcomputer 9.

Audio signal gain adjustment amplifiers 6L and 6R
Performs gain adjustment on the output of the wind noise reduction circuit 5 and supplies it to the recording system encoding processing circuit 7. Here, the gains of the audio signal gain adjustment amplifiers 6L and 6R are controlled by a gain control circuit 10 described later. Further, the recording system encoding processing circuit 7 includes an audio signal gain adjustment amplifier 6.
L and 6R outputs are interleaved, and AAUX (audio AU) described later supplied from the microcomputer 9
X) A process for adding data is performed. Then, data obtained by such processing is supplied to the recording system 8. The recording system 8 performs a process of recording the supplied data on a recording medium such as a magnetic tape.

On the other hand, based on the detection signal supplied from the wind noise reduction circuit 5, the microcomputer 9 generates information on the strength of the wind in a signal format used in the recording wind noise level display unit 11. Is output to the recording wind sound level display unit 11. As information relating to the strength of the wind, for example, a wind sound signal level may be displayed, or a wind speed may be calculated and displayed by a predetermined conversion means. As the wind noise level display unit 11 for recording, for example, an electronic viewfinder,
A liquid crystal monitor or an LED (Light Emitting Diode) is used.

In particular, for an electronic viewfinder, a liquid crystal monitor, and the like, a part of a screen (for example, the upper end of the screen) for displaying a video signal relating to a recording (photographing) object is used as a wind noise level display unit 11 for recording. You may use it. Such a function is realized by using a configuration in which information on the strength of wind generated by the microcomputer 9 is superimposed on a video signal. Further, for example, the microcomputer 9 may control the display / non-display of information relating to the strength of the wind in connection with an external input by a user operation or the like.

Further, the microcomputer 9 generates AAUX data as subcode data including information on the strength of the wind, based on the detection signal, and supplies the AAUX data to the recording system encoding processing circuit 7. The recording system encoding processing circuit 7 performs the encoding process for recording the AAUX data together with the audio signal, as described above. By the way, A
The AAUX data may be recorded together with the video signal by supplying the AUX data to means for performing an encoding process on the video signal.

Next, the wind noise reduction circuit 5 will be described in more detail with reference to FIG. L-side and R-side signals are input to the wind noise reduction circuit 5. These two signals are used by arithmetic unit 2
0 is supplied. The calculator 20 calculates the difference between the two supplied signals. In FIG. 2, from the signal on the L side, R
Although the difference is calculated by subtracting the signal on the side, the difference may be calculated by subtracting the signal on the L side from the signal on the R side. However, the following description of the processing at the subsequent stage of the arithmetic unit 20
This is performed on the assumption that 0 is a signal obtained by subtracting the R-side signal from the L-side signal. The output of the arithmetic unit 20 is supplied to an LPF 21 that passes a component of, for example, 1 kHz or less. The output of the LPF 21 is obtained by extracting a wind noise signal component for the following reason.

First, since the correlation between the L-side signal and the R-side signal is smaller in the wind sound signal component than in the voice signal component, the difference between the L-side signal and the R-side signal ( That is, there is a large possibility that the output of the arithmetic unit 20 remains without canceling each other. Further, the second reason is that the wind noise signal component is generally distributed in a relatively low frequency range (about one hundred and several tens of Hz), so that the possibility of passing through the LPF 21 is large.

The extracted wind noise signal component, that is, LPF
The output of 21 is supplied to an amplifier 22 and an amplifier 32. The amplifier 22 adjusts the gain of the output of the LPF 21,
It is supplied to the absolute value conversion circuit 23. The absolute value circuit 23 performs an absolute value process on the supplied signal, that is, a process for keeping the polarity constant without changing the amplitude of the original signal. The output of the absolute value conversion circuit 23 is the attack characteristic / recovery characteristic setting circuit 2
4 is supplied.

Attack characteristic / recovery characteristic setting circuit 24
Generates a detection signal by performing a process of suppressing a sudden level change to a human's hearing to a supplied signal. As such processing, for example, at the beginning of wind noise, an attack characteristic with a quick response is set in order to improve the followability to a gust or the like. Further, for example, if the response of the control is made faster when the level of the wind sound signal becomes smaller, the point of change in the wind sound signal level tends to give a sense of incongruity in terms of audibility, so that a recovery characteristic for delaying the response is set. The detection signal thus generated is supplied to the amplifiers 32 and 29 each having a configuration of a variable gain amplifier in the microcomputer 9, the AND circuit 10, and the wind noise reduction circuit 5.

On the other hand, the amplifier 32 receives the supplied LPF 2
The gain of the output 1 is adjusted in response to the detection signal. The output of the amplifier 32 is supplied to computing units 25 and 26. In the arithmetic unit 25, the output of the amplifier 32 is subtracted from the L-side signal. On the other hand, in the arithmetic unit 26, since the arithmetic unit 20 calculates the difference by subtracting the R-side signal from the L-side signal, the R-side signal is subtracted from the output of the amplifier 32. Is performed.

The outputs of the calculators 25 and 26 are the difference between the input signals on the L and R sides and the signal obtained by adjusting the gain of the extracted wind noise signal based on the detection signal. The wind noise signal component is reduced. However, in order to more reliably reduce the wind noise signal, the following configuration is provided.

That is, the outputs of the computing units 25 and 26 are supplied to a computing unit 27 and added, and the addition result is an LPF 28 that passes a component of, for example, 200 Hz or less.
Supplied to As the output of the LPF 28, wind noise signal components remaining in the outputs of the arithmetic units 25 and 26 are extracted. Such a wind noise signal component is supplied to the amplifier 29, gain-adjusted, and supplied to the computing units 30 and 31. The gain of the amplifier 29 is controlled based on the detection signal generated by the attack characteristic / recovery characteristic setting circuit 24.

The arithmetic units 30 and 31 calculate the difference between the outputs of the arithmetic units 25 and 26 and the output of the amplifier 29, respectively. As a result, the outputs of the arithmetic units 30 and 31 have a further reduced wind noise signal component. Then, the outputs of the arithmetic units 30 and 31 are used as the output signals on the L and R sides of the wind noise signal reduction circuit 5.

In the wind noise signal reducing circuit 5, as described above, the gains of the amplifiers 32 and 29 are controlled based on the detection signal generated by the attack characteristic / recovery characteristic setting circuit 24. In the present invention, the detection signal is further supplied to the microcomputer 9 or the gain control circuit 10 so that the detection signal is used for processing outside the wind noise signal reduction circuit 5.

That is, according to an embodiment of the present invention, a process for displaying a wind noise signal level at the time of recording based on a detection signal, a process for appropriately adjusting a gain at a stage subsequent to the wind noise reduction process, and a process for displaying a wind noise signal at the time of reproduction. Processing for displaying a signal level is performed. Hereinafter, these processes will be described in order.

First, as shown in FIG. 1, the detection signal is supplied to the microcomputer 9 to drive the recording wind sound level display unit 11 so that the wind sound signal level or the wind sound level is recorded at the time of recording. Information relating to the strength of the wind, such as the wind speed, obtained by converting the sound signal level by a predetermined method is displayed.

Next, a description will be given of a process for appropriately adjusting the gain at a later stage of the wind noise reduction process. For ease of understanding, first, a case where the audio signal level is reduced by the wind noise reduction processing will be described with reference to FIG. FIG. 3A
The case where only an audio signal is input as an input signal is shown. In this case, the signal level of the input signal is A
Since the GC point has not been reached, the AG
The signal level does not change even after the C processing.

On the other hand, FIG. 3B shows a case where the sum of a voice signal and a wind sound signal is input as an input signal. As shown in the left-hand diagram, the signal level of the voice signal is the same as that of FIG. The case where the signal level of the input signal exceeds the AGC point because the signal level of the wind sound signal is large is shown. In such a case, the signal level of the sum of the audio signal and the wind noise signal, which is the input signal, is suppressed to the AGC point. As a result, as shown in the center diagram, the signal level of the audio signal when it is input is It becomes lower than the signal level.
Then, when the wind sound signal is reduced by the wind sound reduction processing, an audio signal having a signal level lower than that in the case of FIG. 3A remains as shown in the diagram on the right.

Such a change in the audio signal level causes a situation where the audio level drops without hearing the noise due to the wind noise, and makes the user feel uncomfortable. In order to improve such a situation, it is effective to adjust the gain after the wind noise reduction processing so as to keep the audio signal level constant in relation to the detection signal. That is, when the wind signal is larger than the audio signal in the input signal and the signal level of the input signal exceeds the AGC point, the audio signal gain adjustment amplifiers 6L and 6R are referred to by referring to the detection signal.
For example, the gain of the amplifier at the subsequent stage of the wind noise reduction circuit 5 may be accurately controlled.

That is, as described in FIG.
The C circuit 3 generates a predetermined signal when the input signal exceeds the AGC point, and supplies the signal to the gain control circuit 10. Further, the detection signal is supplied to the gain control circuit 10 from the wind noise reduction circuit as described above. Gain control circuit 10
Detects, based on these signals, a situation in which the wind noise signal is larger than the audio signal in the input signal and the signal level of the input signal exceeds the AGC point, and such a situation is detected. Sometimes, the gain of the audio signal gain adjustment amplifiers 6L and 6R is appropriately controlled so that the audio signal level is constant.

Further, a process of displaying information relating to the strength of the wind, such as the wind sound signal level, during reproduction will be described with reference to FIG. FIG. 4 is a block diagram showing a configuration relating to reproduction of audio information according to an embodiment of the present invention. Data recorded on the magnetic tape 40 as a recording medium is read by the magnetic heads 50L and 50R, and at an operation timing according to a clock generated by the read signal selection switch 51, the RF signal reproduction amplifier 52, the equalizer 53, and the PLL unit 55. The signals are sequentially processed by the operating A / D converter 54 and supplied to the channel decoder and the ECC circuit 56 as digital signals.

Channel decoder and ECC circuit 56
Generates a reproduced audio signal by subjecting the supplied signal to a decoding process and an error correction process, and is recorded as a subcode together with the audio signal by the method described with reference to FIG. 1 and the like. Play AAUX data. The reproduced audio signal is supplied to the subsequent stage, subjected to an interpolation process and the like, and then supplied to audio generating means such as a speaker.

On the other hand, the reproduced AAUX data is supplied to the microcomputer 57. The microcomputer 57 converts a portion related to the strength of the wind in the AAUX data into a signal format required for the operation of the reproduction wind sound level display unit 58 and supplies the signal format to the reproduction wind sound level display unit 58. In this way,
This allows the user to check information on the strength of the wind, such as the wind sound signal level at the time of recording, at the time of reproduction. As the reproduction wind sound level display section 58, for example, the same one as the recording wind sound level display section 11 described above can be used as shown in FIG.

When the information recorded on the recording medium is reproduced by a predetermined reproducing apparatus, for example, when audio and video are output during reproduction using a television receiver or the like, a part of the screen is reproduced. The hourly wind sound level display unit 58 may be used. In these cases, A
It is necessary to provide a configuration in which information on the strength of the wind obtained by reproducing the AUX data is superimposed on the video signal. The microcomputer 57 controls whether or not to display information relating to the strength of the wind on the reproduction-use wind noise level display unit 58 in relation to an external input such as a user operation. Is also good.

Next, the wind sound level display section 11 used for the recording system and the reproducing system will be described. FIG. 5 shows an example of an on-screen display using an electronic viewfinder or a liquid crystal monitor for displaying video information. For example, the upper left corner of the display surface is used as a region for displaying a wind noise level, and a mark such as a streamer or a windmill is displayed in this region, and the display of such a mark is changed according to the signal level of a wind sound signal or the like. Can be used. More specifically, the time interval of the blinking of the mark is shortened as the signal level of the wind noise signal increases, or, particularly when a mark such as a windmill is used, as the signal level of the wind noise signal increases, A method of displaying the rotation so that the rotation can be seen more quickly is possible.

As the wind sound level display unit 11, for example, an LED or the like may be used, or a liquid crystal monitor or the like for displaying information on the strength of the wind is provided separately from the display for displaying video information. You may do it.

In the embodiment of the present invention described above, the present invention is applied to a digital VTR. The present invention relates to a system for recording and / or reproducing audio information having a microphone, for example, 8 mm. The present invention is also applicable to camcorders, MDs (minidiscs), DATs (digital audio tapes), and the like.

Further, the present invention is not limited to the above-described embodiment, and various applications and modifications can be considered without departing from the gist of the present invention.

[0040]

As described above, the present invention uses the detection signal generated by the wind noise reduction circuit to display information relating to the strength of the wind, such as the level of the wind noise signal, during recording and / or reproduction. Processing other than wind noise reduction processing, such as processing for accurately adjusting the gain in the latter stage of the processing and wind noise reduction processing, is performed.

Therefore, at the time of recording, the user can know the wind noise signal level or information on the strength of the wind such as the wind speed obtained by converting the wind noise signal level by a predetermined method.

Further, at the time of reproduction, the user can know information on the strength of the wind such as the wind speed obtained by converting the wind sound signal level at the time of recording or the wind sound signal level by a predetermined method. For this reason, it is easy to grasp the situation at the time of recording or shooting.

Further, by appropriately performing the gain adjustment in the latter stage of the wind noise reduction processing, it is possible to correct the fluctuation of the audio signal level caused by the wind noise reduction processing. And the audio level can be kept constant. For this reason, it is possible to eliminate or reduce the occurrence of a sense of incongruity at the time of reproduction due to the fluctuation of the audio level.

[Brief description of the drawings]

FIG. 1 is a block diagram for describing a configuration related to recording of audio information according to an embodiment of the present invention.

FIG. 2 is a block diagram for describing a partial configuration of a configuration related to recording of audio information according to the embodiment of the present invention.

FIG. 3 is a schematic diagram for explaining a change in an audio signal level caused by a wind noise reduction process.

FIG. 4 is a block diagram for describing a configuration related to reproduction of audio information according to an embodiment of the present invention.

FIG. 5 is a schematic diagram for explaining wind sound level display performed in one embodiment of the present invention.

[Explanation of symbols]

3 ... AGC circuit, 5 ... Wind noise reduction circuit, 6L, 6
R: audio signal gain adjustment amplifier, 9: microcomputer, 10: gain control circuit, 11: wind noise level display unit for recording, 20: arithmetic unit, 21: LP
F, 23: absolute value conversion circuit, 24: attack characteristic / recovery characteristic setting circuit, 57: microcomputer, 58
..Wind level display for playback

Claims (14)

[Claims] 1. An audio signal recording apparatus for recording an audio signal, comprising: a wind noise reduction unit for performing a wind noise reduction process; and a wind noise reduction process based on a detection signal generated by the wind noise reduction unit. An audio signal recording apparatus characterized by performing processing other than the above. 2. The gain adjusting means according to claim 1, wherein said gain adjusting means is provided at a stage subsequent to said wind noise reduction processing and performs gain adjustment on an audio signal, and said gain adjusting means is related to said detected signal. An audio signal recording device, comprising: a gain control unit. 3. The gain control unit according to claim 2, wherein the gain control unit controls the gain adjustment unit based on a signal indicating a magnitude relationship between an AGC point referred to in AGC control and an input signal level, and the detection signal. An audio signal recording apparatus characterized in that 4. The audio signal recording apparatus according to claim 1, further comprising means for generating sub-code data including information on the strength of the wind based on the detected signal. 5. The audio signal recording device according to claim 4, further comprising means for recording the subcode data together with an audio signal. 6. The audio signal recording apparatus according to claim 4, further comprising a function of recording a video signal, wherein the subcode data is recorded together with the video signal. 7. The display device according to claim 1, further comprising a display unit for recording for displaying information to be recorded or conditions at the time of recording in real time, wherein the display unit for recording is based on the detection signal. An audio signal recording device controlled to display information relating to strength. 8. The audio signal according to claim 7, further comprising means for controlling display / non-display of the information relating to the strength of the wind in accordance with an operation from outside with respect to the display means for recording. Recording device. 9. The audio signal recording apparatus according to claim 4, wherein the information on the strength of the wind is a wind sound signal level or a wind speed obtained by a predetermined conversion unit based on the wind sound signal level. . 10. The audio according to claim 7, wherein the display means for recording displays a video signal, and the information on the strength of the wind is superimposed on the video signal in an analog manner. Signal recording device. 11. An audio reproducing apparatus for reproducing an audio signal recorded on a predetermined recording medium, comprising: means for separating a reproduced audio signal from the reproduced sub-code data. An audio signal reproduction apparatus, wherein a reproduction display means for displaying information is controlled based on the subcode data so as to display information relating to wind strength. 12. The display device according to claim 11, wherein the display means for reproduction displays a video signal, and the information relating to the strength of the wind is superimposed on the video signal in an analog manner. Audio signal reproducing device. 13. The audio signal reproducing apparatus according to claim 11, further comprising means for externally controlling display / non-display of the information on the strength of the wind with respect to the display means for reproduction. 14. An audio signal recording / reproducing apparatus for recording and reproducing an audio signal, comprising: a wind noise reduction unit for performing a wind noise reduction process; An audio signal recording / reproducing apparatus for performing processing other than sound reduction processing.