JP3106774B2 - Digital sound field creation 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 digital sound field generating apparatus for performing sound effect processing on an audio signal from a sound source in order to output the audio signal with a sense of realism.

[0002]

2. Description of the Related Art Conventionally, according to such a digital sound field generating apparatus, a reflected sound program for adding only a reflected sound to an audio signal from a sound source in order to generate an optimum sound field, It is necessary to use two types, a reverberation sound program for adding a reflection sound and a reverberation sound to the audio signal.

That is, the reflected sound program accurately reproduces each reflected sound in a relatively narrow space sound field expression, and the reflected sound by the reverberation sound program in a large space sound field expression. The sound is played with emphasis on reverberation.

As described above, these two programs are generally indispensable in the digital sound field generating apparatus.

Next, such a conventional digital sound field generating apparatus will be described with reference to a block diagram shown in FIG.

In FIG. 6, a digital sound field generating apparatus includes a low-pass filter (hereinafter, simply referred to as an LPF) 12 for limiting a band of an input analog signal, and samples and quantizes an output signal of the LPF 12. A / D converter 13 that outputs a digital signal through a digital signal processor, and a digital signal processor (hereinafter simply referred to as DSP) that performs sound effect processing for adding a sound effect such as a reflected sound or a reverberant sound to the digital signal.
20; a memory 21 for storing data; a D / A converter 16 for decoding an input digital signal and outputting a PAM wave; an LPF 17 for interpolating the PAM wave; Mute circuit 2
2 and a microcomputer 23 for controlling the DSP 20 and the mute circuit 22. The D / A converter 16, the LPF 17, and the mute circuit 22 are provided two by two, and these are connected to the input unit for the L speaker or the R speaker.

As shown in FIG. 7, the DSP 20 has a program memory area 20a storing a reflected sound program and a reverberation sound program, and a sound field to be reproduced, that is, a sound subjected to reflection sound processing and reverberation sound processing. A coefficient data memory area 20b for storing level coefficient data for setting a level of a reflected sound or a reverberant sound corresponding to the field, and a multiplier (not shown) for performing arithmetic processing using the level coefficient data and delay setting data to be described later. have.

In the memory 21, as shown in FIG.
A delay setting data memory area 21a for storing delay setting data for setting a delay time corresponding to the sound field to be reproduced.

Next, the operation of the conventional digital sound field creating apparatus configured as described above will be described.

The LPF 12 supplies the audio signal from a sound source (not shown) to the A / D converter 13 after limiting the band. The A / D converter 13 samples and quantizes the audio signal, that is, converts the signal into a digital signal, and supplies the digital signal to the DSP 20.

The microcomputer 23 selects a reflected sound program or a reverberation sound program of the DSP 20 in accordance with a predetermined operation, and similarly performs sound effect data corresponding to the selected program, that is, level coefficient data and delay setting data. Select

The DSP 20 subjects the audio signal to digital signal processing by a multiplier based on a selected program and selected sound effect data, and supplies an audio processed signal to which a sound effect is added to the D / A converter 16. I do. The D / A converter 16 decodes the audio processing signal, that is, supplies the LPF 17 with the PAM-wave processed audio processing signal. The LPF 17 performs interpolation on the audio processing signal, and supplies the audio processing signal as the analog signal to a sound output unit (not shown) via a mute circuit 22.

When the reproduction sound field is switched in accordance with a predetermined operation during execution of the reflected sound program or reverberation sound program of the DSP 20, that is, execution of the reproduction sound field, the reproduced sound field changes instantaneously. . For this reason, since the configurations of the reflected sound and the reverberant sound are different, the waveform becomes discontinuous and an abnormal sound occurs, or an abnormal sound occurs due to a difference in sound effect data.

Therefore, when switching to the reflected sound program or the reverberant sound program during execution of the reproduction sound field, the microcomputer 23 supplies a control signal to the mute circuit 22. The mute circuit 22 mutes the input audio processing signal in response to the control signal to set a mute state.

Therefore, according to the above-mentioned conventional digital sound field generating apparatus, even if the reproduction sound field is switched during execution of the reproduction sound field of the DSP 20, it is possible to prevent a situation in which an abnormal sound occurs and gives a sense of incongruity to the user. At the same time, the reproduction sound field can be switched.

[0016]

However, according to the above-described conventional digital sound field generating apparatus, if the sound field is switched during execution of the sound field, the sound is interrupted and the sound is interrupted. There is a problem that the atmosphere of the sound is impaired.

The present invention has been made in view of the above-mentioned problems, and an object thereof is to switch the reproduction sound field without deteriorating the atmosphere of the reproduction sound even during the execution of the reproduction sound field. It is to provide a digital sound field creation device capable of performing the following.

[0018]

In order to achieve the above object, a digital sound field generating apparatus according to the present invention comprises: a digital conversion means for converting an audio signal from a sound source into a digital signal to directly output a sound signal; Effect corresponding to processing program
Storage means for storing the sound data, the sound effect processing program in accordance with an input, and an operation means for selecting the sound effect data corresponding to the sound effect processing program, the
And sound field creation means for sending the audio processing signal by synthesizing the direct sound signal and the sound effect signal subjected to the sound effect processing on the direct sound signal based on the sound effect data, an operation input from said operating means the sound field creation the sound effect data in accordance with the
Control means for outputting a raw device, the audio processing signal or a digital sound field creation device having an analog converting means for analog conversion, the sound field creation means, the effect <br/> Hateon process When there is an operation input from the operation unit during execution of the program , the sound effect signal is faded out, and when the sound effect signal is lower than the audible level , the control unit is controlled by the operation unit. Sound effect data corresponding to the selected sound effect processing program is input to the sound field creating means, and the sound field creating means inputs the sound field data based on the sound effect data.
The sound effect signal is faded in .

[0019]

With this configuration, even if the sound effect processing program of the reproduction sound field is switched during execution of the sound effect processing program, the sound effect signal is faded out to a predetermined level without directly affecting the sound signal. Since the sound effect processing program is switched to fade in, the reproduced sound field can be switched without damaging the atmosphere of the reproduced sound.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the digital sound field generating apparatus of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram schematically showing a digital sound field creation device according to the present invention.
The same components as those in the related art are denoted by the same reference numerals, and the description of the configuration and operation is omitted.

In the digital sound field creation device shown in FIG.
LPF 12 which is digital conversion means for inputting an audio signal from a sound source 11 such as a CD player and converting the audio signal into a digital signal
And A / D converter 13 and memory 1 as storage means
4 and DSP 15 as sound field creation means, and each D / D as analog conversion means connected to the input section of each speaker (not shown).
It has an A-converter 16 and an LPF 17, a sound field selection key 18 as an operation means for switching a reproduction sound field in accordance with a user's input operation, and a microcomputer 19 as a control means for controlling the DSP 15.

2 and 3 are inside the DSP 15.
, A direct sound processing unit 15a that directly processes an audio signal input to the DSP 15, a reflected sound processing unit 15b that performs reflected sound processing on the audio signal, and a reverberation processing unit 15c that performs reverberation processing on the audio signal. And a memory clear processing unit 15 for clearing sound effect data in all sound effect processing, for example, reflected sound processing and reverberation sound processing.
d, a multiplier 15e that controls the sound volume by multiplying the sound effect data, and an adder 15f that adds the audio signal from the direct sound processing unit 15a and the output signal that is the sound effect from the multiplier 15e. As shown in FIG. 3, a program memory 15g storing a sound effect processing program as four processing modules of a direct sound processing unit 15a, a reflected sound processing unit 15b, a reverberation sound processing unit 15c, and a memory clear processing unit 15d; And a level coefficient data memory area 15h for storing level coefficient data for setting the levels of the reflected sound and the reverberant sound corresponding to the sound field to be subjected to the reflection, reverberation and direct sound processing. ing.

In the memory 14, as shown in FIG.
A delay setting data memory area 14a for storing delay setting data for setting a delay time corresponding to the sound field to be reproduced.

Next, the operation of the digital sound field creating apparatus of the present invention configured as described above will be described with reference to FIGS.

First, the operation for executing a normal sound effect processing program will be described. The LPF 12 and A
The / D converter 13 converts the audio signal input from the sound source 11 into a digital signal and supplies the digital signal to the DSP 15. In response to the operation of the sound field selection key 18, a sound effect processing program, level coefficient data and delay setting data, that is, sound effect data are selected. The direct sound processing unit 15a of the DSP 15 converts the audio signal as a direct sound signal into the adder 15f and the reflected sound processing unit 1 corresponding to the sound effect processing program selected by the sound field selection key 18.
5b or the reverberation processing unit 15c. Here, it is assumed that the sound field selection key 18 has selected the reflected sound processing program.

The reflected sound processing unit 15b supplies the direct sound signal to a multiplier 15e, and the multiplier 15e generates the direct sound signal based on the sound effect data selected by the sound field selection key 18. The signal is subjected to sound effect processing and a sound effect signal is supplied to the adder 15f.

The adder 15f generates an audio processing signal by synthesizing the sound effect signal and the direct sound signal, and converts the audio processing signal into a D / A converter 1.
6 and the LPF 17 to a sound output unit (not shown).

It should be noted that the reverberation sound processing program is executed by the same operation as the operation of the reflected sound processing program.

Next, the operation for switching to another reproduction sound field during execution of the reproduction sound field will be described. First, the sound field selection key 18 supplies a switching signal to the microcomputer 19 in response to an input operation for switching to reverberation sound processing when the DSP 15 executes reflected sound processing. The microcomputer 19 supplies a switching start flag to the DSP 15 according to the switching signal. The DS
P15 fades out the sound effect in terms of audibility by subtracting a certain amount from 1 for a sound effect coefficient that controls the sound effect volume based on the sound effect data in accordance with the switching start flag. The fixed amount FO is a value to be subtracted every sampling period, that is, a value obtained by dividing the sampling period by a time required for fade-out (FO = 1 / n; n is a natural number).

When the effect sound volume coefficient becomes 0, the subtraction processing and the reflection sound processing are completed, and the processing shifts to the memory clear processing. In the memory clear processing, 0 data is written to various data memories used for the reflection sound processing. The writing of the 0 data is for preventing the generation of abnormal noise immediately after the reproduction sound field switching.

When the writing of 0 data in the memory clear processing is completed, the microcomputer 19 supplies a reverberation processing start flag to the DSP 15. The DSP 15 ends the memory clear processing according to the reverberation processing start flag,
Move on to reverberation processing. The DSP 15 fades in the sound effect in terms of audibility by adding a fixed amount from 0 to a sound effect coefficient for controlling the sound effect sound volume based on the selected sound effect data. The fixed amount F
I is a value added for each sampling period, that is, a value obtained by dividing the sampling period by the time required for fade-in (FI = 1 / n; n is a natural number).

When the effect volume coefficient becomes 1, the addition process is terminated and the switching of the sound field reproduction is completed.

Next, the processing operation of the DSP 15 in the above series of operations will be described with reference to the flowchart shown in FIG.

In step S1 in FIG. 5, the direct processing section 15a is caused to perform direct sound processing for directly processing an audio signal. In step S2, it is determined whether a switching start flag has been received from the microcomputer 19 in response to an input operation of the sound field selection key 18. If the switching start flag has been received, it is determined in step S3 whether or not the sound effect coefficient, which is the sound effect signal, is zero.

If the effect volume coefficient is not 0, the effect volume coefficient is decreased by a predetermined amount in step S4, and it is determined in step S5 whether the effect volume coefficient is 0. If the sound effect coefficient is 0, the memory clear processing section 15d performs a memory clear processing of writing 0 data to various data memories used for the sound effect processing in step S6, and directly outputs a sound to the adder 15f in step S7. The signal and the sound effect signal are combined to output an audio processing signal, and the process proceeds to step S1.

If the switching start flag has not been received in step S2, it is determined in step S8 whether or not the effect volume coefficient is at the expiration level of "1". If the effect sound volume coefficient is 1, the process proceeds to step S5. If the effect sound volume coefficient is not 1, the effect sound volume coefficient is added by a fixed amount in step S9, and the process proceeds to step S5.

If the effect volume coefficient is not 0 in step S5, it is determined in step S10 whether a reflected sound processing start flag has been received. If the reflection sound processing start flag has been received, the reflection sound processing is performed in step S11 to generate a sound effect signal, and the process proceeds to step S7. Unless the reflection sound processing start flag is received in step S10. In step S12, reverberation processing is performed to generate a sound effect signal, and the process proceeds to step S7.

According to the above embodiment, even if the reproduction sound field is switched during execution of the reproduction sound field, the reproduction sound field is switched after setting the effect volume coefficient to 0 without directly affecting the sound processing. Therefore, without generating abnormal noise, without interrupting the playback sound,
The playback sound field can be switched.

Further, by determining the fixed amount required for adding and subtracting the effect volume coefficient, the time required for fade-in and fade-out can be freely set to be about 1 second.

In the above embodiment, an example in which the reflection sound processing is switched to the reverberation processing is described. However, the switching between the reverberation processing, the reflection processing, and the reflection processing and the reverberation processing accompanying the selection of the sound effect data is performed. Even at the same time, the same effect can be obtained.

Further, in the above embodiment, the reproduction sound field is switched after the effect volume coefficient becomes 0, but after the effect volume coefficient becomes such that the effect volume becomes lower than the audible level. The reproduction sound field may be switched.

Further, according to the digital sound field generating apparatus of the present invention, if the reproduced sound field is switched in synchronization with the video, it is possible to easily realize a video field-synchronized sound field generation without a sense of incongruity. Can be.

[0043]

According to the digital sound field creating apparatus of the present invention configured as described above, the sound effect processing program is executed.
When there is an operation input from the operation
Fade out the signal and make this sound effect signal an audible level
Use a configuration that fades in the sound effect signal when
So that after the original sound effect signal fades out
As the new sound effect signal fades in,
You can switch the sound field without harming the atmosphere
You. Also, until the original sound effect signal is completely muted
Without waiting, listen to the sound effect signal that is synthesized with the direct sound signal.
Immediately after fading out below the bell, a new sound effect
Issue fades in the sound.
Switch the playback sound field in a short time without
Things.

Therefore, even if the sound effect processing program of the reproduced sound field is switched during execution of the sound effect processing program,
Since the sound effect signal is faded out to a predetermined level without affecting the direct sound signal, the sound effect processing program is switched and faded in.
The reproduced sound field can be switched while generating a smooth sound without interruption of the reproduced sound without generating abnormal noise.

[Brief description of the drawings]

FIG. 1 is a block diagram schematically showing a digital sound field creation device according to the present invention.

FIG. 2 is a block diagram schematically showing the inside of a DSP of the digital sound field creation device of the present invention.

FIG. 3 is a memory map of a DSP and a memory of the digital sound field creation device of the present invention.

FIG. 4 is an explanatory diagram showing an execution state of a DSP of the digital sound field creation device of the present invention on a time axis.

FIG. 5 is a flowchart showing an operation process of the DSP of the digital sound field creation device of the present invention.

FIG. 6 is a block diagram schematically showing a conventional digital sound field creation device.

FIG. 7 is a memory map diagram of a DSP and a memory of a conventional digital sound field generating apparatus.

[Explanation of symbols]

 Reference Signs List 11 sound source 12 LPF (digital conversion means) 13 A / D converter (digital conversion means) 14 memory (storage means) 15 DSP (sound field creation means) 16 D / A converter (analog conversion means) 17 LPF (analog conversion means) 18 Sound field selection key (operation means) 19 Microcomputer (control means)

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04R 3/00 310 G10K 15/12

Claims (3)

(57) [Claims] 1. A digital conversion means for converting an audio signal from a sound source into a digital signal to directly output a sound signal; a storage means for storing sound effect data corresponding to a sound effect processing program; A sound processing program, operating means for selecting the sound effect data corresponding to the sound effect processing program, and the direct sound signal and the sound effect.
And sound field creation means for sending the audio processing signal by synthesizing the sound effect signal subjected to the sound effect processing on the direct sound signal on the basis of Hateon data, the effect in accordance with an input from said operating means a digital sound field creation device comprising a control means for outputting sound data to the sound field creation means, and analog converting means for analog-converting said audio processing signal, the sound field creation means, the effect Sound processing program
When the there is an operation input from the operating means during the execution,
Fade the sound effect signal, the sound effect signal variable
Becomes below hearing level, the control means, the sound effect data corresponding to the sound effect processing program selected by said operating means is inputted to the sound field creation means, the sound field creation means, this A digital sound field creation device, wherein the sound effect signal is faded in based on sound effect data. 2. An audio signal from a sound source is digitally transformed.
Digital conversion means for converting and outputting sound signals directly, and effects
Storing sound effect data corresponding to the sound processing program
Storage means and the sound effect processing program in accordance with an operation input.
Sound effect corresponding to the sound effect processing program
Operating means for selecting data, the direct sound signal and the effect
Applying sound effect processing to the direct sound signal based on the fruit sound data
Combines the processed sound effect signal and sends out the audio processing signal
Sound field creation means for responding to an operation input from the operation means.
Output the sound effect data to the sound field creation means.
Control means for converting the audio processing signal into an analog signal
Analog conversion means and video display means for displaying video
A digital sound field creation apparatus having the sound field creation hand
The step shows that the operation means is being executed while the sound effect processing program is being executed.
Synchronized with video switching when operation input from the stage
And fades out the sound effect signal.
When the signal falls below a predetermined level, the control means
Corresponding to the sound effect processing program selected by the operation means
The sound effect data is input to the sound field creation means, and the sound field creation means is input.
The raw means generates the sound effect signal based on the sound effect data.
Digital sound field creation, characterized in that the fade in the
apparatus. 3. An audio signal from a sound source is digitally transformed.
Output the sound signal directly and select it according to the operation input.
The sound effect processing program and the sound effect processing program
The direct sound based on the sound effect data corresponding to the
A sound effect signal obtained by subjecting a signal to sound effect processing and the direct sound signal
To generate an audio processing signal,
Digital sound field creation method to convert audio processing signal to analog
Wherein the operation is performed during execution of the sound effect processing program.
Fade out the sound effect signal when there is an input
When the sound effect signal falls below the audible level, the above operation is performed.
Corresponds to the sound effect processing program selected according to the work input
Fades the sound effect signal based on the corrected sound effect data.
A digital sound field creation method characterized by: