JP2004064363A - Digital audio processing method, digital audio processing device, and digital audio recording medium - Google Patents

Abstract

A virtual stereophonic sound effect can be obtained only for a specific component such as a reproduced or received music piece.
A performance component of input digital audio signals (L1, R1) is extracted as digital audio signals (La, Ra) at a stage preceding a specific component extraction unit (20). In the virtual stereophonic sound output mode, the extracted vocal components are used to extract the vocal components of the input digital audio signals L1 and R1 as digital audio signals L2 and R2. At 30, the digital audio signal C2 converted into one channel is subjected to virtual stereophonic sound processing. In the karaoke output mode, the signals La and Ra composed of performance components are extracted as they are as signals L2 and R2.
[Selection diagram] FIG.

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method and an apparatus for processing a digital audio signal to obtain a virtual stereophonic effect.
[0002]
[Prior art]
Digital audio signal processing is performed by digital audio signal processing so that a listener (user) can recognize as a reproduced sound from a sound source in various directions (angles) and distances in a three-dimensional space using only left and right two-channel audio reproduction outputs. There is virtual stereophonic processing for processing signals.
[0003]
This is done by recording in advance how the sound or voice sounds according to the positional relationship from the listener's head as a model, analyzing the recorded model data, and processing coefficients at each assumed position. Is set, and the processing coefficient is dynamically applied to the digital audio signal in actual audio reproduction.
[0004]
A digital audio signal of two channels on the left and right is reproduced from a commercially available music recording medium, and the reproduced digital audio signal is subjected to the virtual stereophonic sound processing, so that a stereophonic sound such as a multi-channel reproduction is executed. Sound effects can be obtained.
[0005]
Separately from this, there is a karaoke process for reproducing a digital audio signal including a vocal part and a performance component from a recording medium and removing only the vocal part from the reproduced digital audio signal.
[0006]
This is because, in recent songs, the vocal part is often localized in the center and the approximate frequency band of the human voice is taken into account. By performing filter processing or the like, the vocal part is easily removed, and audio reproduction is performed using only the remaining performance components.
[0007]
As a result, it is possible to obtain a playback sound of only the accompaniment substantially similar to the original music on the recording medium, and enjoy karaoke by playing a commercially available music recording medium instead of a recording medium dedicated to karaoke.
[0008]
[Problems to be solved by the invention]
However, in the above-described conventional method of virtual stereophonic sound processing, since virtual stereophonic sound processing is performed on a digital audio signal recorded on a recording medium such as a disk, all the components such as music recorded on the recording medium are removed. Is subjected to the virtual three-dimensional sound processing, and it is not possible to obtain a virtual three-dimensional sound effect only for a specific component.
[0009]
Therefore, the present invention is such that a virtual three-dimensional sound effect can be obtained only for a specific component such as a reproduced or received music.
[0010]
[Means for Solving the Problems]
The digital audio processing method of the present invention comprises:
By localization state or frequency band of each component in the input digital audio signal, extracting a specific component of the input digital audio signal,
Subjecting the extracted specific component to virtual stereophonic sound processing to obtain an output digital audio signal;
It is provided with.
[0011]
In the above digital audio processing method, virtual stereophonic sound processing is performed only on a specific component, such as a music piece obtained as an input digital audio signal. Obtainable.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
[One Embodiment of the Entire System: FIG. 1]
FIG. 1 shows an embodiment of a digital audio processing apparatus according to the present invention. The digital audio processing apparatus of the present invention reproduces digital audio signals of left and right two channels recorded on an optical disc, and converts the reproduced digital audio signals into digital audio signals of the present invention. In this case, the digital audio signal is processed by a digital audio processing method, audio is reproduced by the processed output digital audio signal, and the processed output digital audio signal is recorded on a hard disk.
[0013]
On the optical disc 1, digital audio signals of two channels, left and right, digitized by PCM (Pulse Code Modulation) or the like are interleaved, modulated by EFM (Eight to Fourteen Modulation) or the like, and recorded.
[0014]
The optical disc 1 is rotated by a spindle motor 11, and the optical pickup 12 is fed by a feed motor 13 in the radial direction of the optical disc 1.
[0015]
The reproduced RF signal from the optical pickup 12 is supplied to an RF signal processing circuit 15, from which a speed error signal, a tracking error signal, and a focus error signal are obtained. The rotation of the optical disk 1, the rotation of the optical pickup 12, and the tracking and focus of the optical pickup 12 are controlled by the optical pickup 1.
[0016]
Further, a reproduced digital audio signal is obtained from the RF signal processing circuit 15, and this is EFM-demodulated by a demodulation DSP (Digital Signal Processor) 17, error-corrected, deinterleaved, and subjected to compression encoding and encryption at the time of recording. Decoding is performed in accordance with the conversion, and the reproduction digital audio signals L1 and R1 of the left and right two channels are obtained from the demodulation DSP 17.
[0017]
Also, control information for reproduction control is obtained from the demodulation DSP 17 and supplied to the reproduction control circuit 18 for use in the rotation control of the optical disk 1 and the feed control of the optical pickup 12 by the servo control circuit 16.
[0018]
The left and right two-channel reproduced digital audio signals L1 and R1 from the demodulation DSP 17 are supplied to the specific component extraction unit 20 as input digital audio signals, and the specific components are extracted as described later. In the following, an “audio signal” is a digital audio signal unless otherwise noted as an analog audio signal.
[0019]
In this embodiment, as will be described later, one of the normal output, the karaoke output, the virtual stereophonic sound output, and the mixed output can be selected by the control of the control unit 70 based on the operation on the operation unit 80. .
[0020]
According to the selected output mode, the specific component extraction unit 20 outputs two-channel audio signals L2 and R2 for normal output and karaoke output, and one-channel audio for virtual stereophonic sound output, as described later. The signal C2 and two-channel audio signals La and Ra for mixed output are obtained.
[0021]
The audio signal C2 for outputting the virtual stereophonic sound is supplied to the virtual stereophonic sound processing unit 30 and subjected to virtual stereophonic sound processing as described later, and the two-channel audio signal L3 after the processing from the virtual stereophonic sound processing unit 30 , R3 are obtained.
[0022]
Further, the addition circuit 43L adds the audio signals L3 and La, the addition circuit 43R adds the audio signals R3 and Ra, and outputs the audio signals L2 and R2, the audio signals L3 and R3, and the outputs of the addition circuits 43L and 43R. Are supplied to the selector 41.
[0023]
In the selector 41, the left and right two-channel audio signals are selected as the output audio signals L5 and R5 according to the output mode, as described later.
[0024]
The selected output audio signals L5 and R5 are filtered by digital filters 51L and 51R in accordance with the recording band of the audio signal recorded on the optical disc 1, and then are converted to analog audio signals by D / A converters 52L and 52R. Converted to a signal. The two-channel analog audio signals are amplified by the audio amplifier circuits 53L and 53R and supplied to the speakers 54L and 54R.
[0025]
Further, in this embodiment, the output audio signals L5 and R5 obtained from the selector 41 are recorded and processed by the hard disk recording / reproducing processing unit 61 under the control of the control unit 70 based on the operation on the operation unit 80, and the hard disk device It is recorded on the hard disk in the unit 62.
[0026]
The audio signal recorded on the hard disk is reproduced from the hard disk under the control of the control unit 70 based on the operation on the operation unit 80, subjected to reproduction processing by the hard disk recording / reproduction processing unit 61, and supplied to the reproduction output unit 50. Audio reproduction is performed in the same manner as in reproduction of No. 1.
[0027]
[First Example of Specific Component Extraction and Virtual Stereophonic Processing: FIGS. 2 to 6]
(Extract specific components)
As an example, as shown in FIG. 2, the specific component extraction unit 20 includes coefficient multiplication circuits 21L, 21R, 22L, 22R, 23L, 23R, 24L, 24R, digital filters 25L, 25R, and addition circuits 26, 27L, 27R. , 28L, 28R, 29.
[0028]
The coefficients of the coefficient multiplication circuits 21L and 21R are set to coefficient values having opposite signs and equal absolute values, as indicated by K1 and -K1.
[0029]
Therefore, the output signals of the coefficient multiplying circuits 21L and 21R are added by the adding circuit 26, so that components existing in the same phase in the input audio signals L1 and R1 of the left and right two channels, specifically, localized in the center. The vocal component is removed, and an audio signal including a performance component is obtained from the addition circuit 26.
[0030]
The digital filters 25L and 25R attenuate a human voice band, for example, a frequency component of 200 Hz to 3 kHz in the input audio signals L1 and R1. Therefore, from the digital filters 25L and 25R, audio signals composed of performance components from which vocal components have been removed are obtained.
[0031]
That is, in this example, depending on the localization state in the input audio signals L1 and R1, the performance components in the input audio signals L1 and R1 are extracted by the coefficient multiplication circuits 21L and 21R and the addition circuit 26, and the input audio signal L1 , R1, the performance components in the input audio signals L1, R1 are extracted by the digital filters 25L, 25R.
[0032]
Then, the output signals of the adder 26 are added to the output signals of the digital filters 25L and 25R by the adder circuits 27L and 27R, respectively. From the adder circuits 27L and 27R, the left and right two-channel audio signals La and Ra is obtained.
[0033]
Furthermore, in the virtual stereophonic sound output mode and the mixed output mode described later, the addition is performed by setting the coefficient K2 of the coefficient multiplying circuits 22L and 22R to 1 and setting the coefficient K3 of the coefficient multiplying circuits 23L and 23R to −1. The circuits 28L and 28R subtract the audio signals La and Ra composed of the performance components from the adders 27L and 27R from the input audio signals L1 and R1 passed through the coefficient multiplying circuits 22L and 22R as they are. As the output signals L2 and R2 of the circuits 28L and 28R, audio signals of two channels on the left and right which are composed of vocal components in the input audio signals L1 and R1 are obtained.
[0034]
That is, in the virtual stereophonic sound output mode and the mixed output mode, which will be described later, the specific component extraction unit 20 extracts a performance component on the one hand as a specific component in the input audio signals L1 and R1, and a vocal component on the other. Is extracted.
[0035]
The coefficient K2 of the coefficient multiplying circuits 22L and 22R, the coefficient K3 of the coefficient multiplying circuits 23L and 23R, and the coefficient K4 of the coefficient multiplying circuits 24L and 24R are set by the control unit 70 according to the output mode as described later.
[0036]
Instead of double extracting and adding the performance components as described above, the configuration may be such that the performance components are extracted only from the localization state, or the performance components are extracted only from the frequency band.
[0037]
Although not shown in FIG. 2, a delay circuit may be provided on the output side of the addition circuit 26 in order to correct the time delay of the output signals of the digital filters 25L and 25R with respect to the output signal of the addition circuit 26. In addition, the audio signals La and Ra composed of performance components, which are output from the adding circuits 27L and 27R, may have a stereo effect by a delay circuit or the like.
[0038]
(Virtual stereo sound processing)
In the virtual stereophonic sound processing unit 30, in a virtual stereophonic sound output mode and a mixed output mode, which will be described later, the input audio signals L <b> 1 and R <b> 1 obtained from the addition circuit 29 of the specific component extraction unit 20 are converted into one channel composed of vocal components. The audio signal C2 is subjected to virtual stereophonic sound processing.
[0039]
Specifically, in this example, a process is performed such that the position of the sound image by the audio signal C2 is dynamically changed and controlled in the three-dimensional space by the control of the control unit 70 based on the operation of the operation unit 80.
[0040]
Therefore, in advance, how the sound or voice is heard is recorded as a model based on the positional relationship from the listener's head, and the recorded model data is analyzed to calculate the processing coefficient at each assumed position. It is calculated and set in the virtual stereophonic sound processing unit 30.
[0041]
The operation unit 80 can dynamically designate a position in a three-dimensional space by a button group or an analog controller that can be controlled in multiple directions.
[0042]
The control unit 70 converts the designated position into position information and sends it to the virtual stereophonic sound processing unit 30. The position information can be, for example, three-dimensional coordinate information indicating the designated position as a rotation angle, a tilt angle (elevation angle and depression angle), and a distance on a horizontal plane with the listener position as a center.
[0043]
Based on the position information, the virtual stereophonic processing unit 30 selects a processing coefficient corresponding to the designated position from the set coefficient group and performs virtual stereophonic processing on the audio signal C2. The processed audio signal is output as two-channel audio signals L3 and R3.
[0044]
It should be noted that, in addition to the processing using such coefficients, for example, by adding an effect of a sense of distance by a filter process or an effect of a Doppler effect using a pitch conversion process, the realism of the sound expression by the distance or the movement can be further improved. Can be improved.
[0045]
(Normal output mode: Fig. 3)
In the normal output mode, as shown in FIG. 3, the coefficient K2 of the coefficient multiplying circuits 22L and 22R is set to 1 and the coefficient K3 of the coefficient multiplying circuits 23L and 23R is set to 0.
[0046]
Therefore, at this time, the left and right two-channel input audio signals L1 and R1 are supplied as they are to the selector 41 as the audio signals L2 and R2 through the coefficient multiplying circuits 22L and 22R and the adding circuits 28L and 28R. Are switched to a state of selecting the audio signals L2 and R2, and are obtained from the selector 41 as output audio signals L5 and R5.
[0047]
Since the selector 41 is switched to a state of selecting the audio signals L2 and R2, at this time, the value of the coefficient K4 of the coefficient multiplying circuits 24L and 24R, the audio signals L3 and R3 output from the virtual stereophonic sound processing unit 30, and the adding circuit The audio signals L4 and R4 output from the 43L and 43R can be ignored.
[0048]
(Karaoke output mode: Fig. 4)
In the karaoke output mode, contrary to the normal output mode, as shown in FIG. 4, the coefficient K2 of the coefficient multiplying circuits 22L and 22R is set to 0, and the coefficient K3 of the coefficient multiplying circuits 23L and 23R is set to 1.
[0049]
Therefore, at this time, the left and right two-channel audio signals La and Ra composed of the performance components from the above-described addition circuits 27L and 27R are directly passed through the coefficient multiplication circuits 23L and 23R and the addition circuits 28L and 28R. R2 is supplied to the selector 41. At this time, the selector 41 is switched to a state of selecting the audio signals L2 and R2, so that the selector 41 obtains output audio signals L5 and R5.
[0050]
Since the selector 41 is switched to a state of selecting the audio signals L2 and R2, at this time, the value of the coefficient K4 of the coefficient multiplying circuits 24L and 24R, the audio signals L3 and R3 output from the virtual stereophonic sound processing unit 30, and the adding circuit The audio signals L4 and R4 output from the 43L and 43R can be ignored.
[0051]
(Virtual stereo sound output mode: Fig. 5)
In the virtual stereophonic sound output mode, as shown in FIG. 5, the coefficient K2 of the coefficient multiplying circuits 22L and 22R is set to 1 as in the normal output mode, and the coefficient K3 of the coefficient multiplying circuits 23L and 23R is set to the karaoke output mode. In contrast, the coefficient K4 of the coefficient multiplying circuits 24L and 24R is set to, for example, 1/2 in consideration of overflow.
[0052]
Therefore, at this time, as described above, in the adder circuits 28L and 28R, the input audio signals L1 and R1 passed through the coefficient multiplying circuits 22L and 22R as they are, and the audio signal composed of performance components from the adder circuits 27L and 27R. La and Ra are subtracted, and audio signals composed of vocal components in the input audio signals L1 and R1 are obtained as output signals L2 and R2 of the adding circuits 28L and 28R.
[0053]
In the virtual stereophonic sound output mode, the addition circuit 29 adds the left and right two-channel audio signals L2 and R2 of the vocal component at a ratio of 1: 1, and the output signal C2 of the addition circuit 29 includes the vocal component. An audio signal of one channel is obtained.
[0054]
Further, in the virtual stereophonic sound output mode, the virtual stereophonic sound processing unit 30 performs the above-described virtual stereophonic processing on the one-channel audio signal C2 including the vocal components, and performs the virtual stereophonic sound processing. From the unit 30, audio signals L3 and R3 of two channels on the left and right composed of the processed vocal components are obtained.
[0055]
Then, the left and right two-channel audio signals L3 and R3 composed of the vocal components after the processing of the virtual stereophonic sound are supplied to the selector 41. At this time, the selector 41 is switched to a state of selecting the audio signals L3 and R3. , Output audio signals L5 and R5 from the selector 41.
[0056]
Since the selector 41 is switched to a state of selecting the audio signals L3 and R3, at this time, the audio signals L2 and R2 output from the addition circuits 28L and 28R and the audio signals L4 and R4 output from the addition circuits 43L and 43R become Can be ignored.
[0057]
As described above, in the virtual three-dimensional sound output mode, the virtual three-dimensional sound processing is performed only on the vocal components of the music obtained as the input audio signals L1 and R1, and the virtual three-dimensional sound effect is obtained only on the vocal components. Can be.
[0058]
(Mixed output mode: Fig. 6)
In the mixed output mode, the coefficient K2 of the coefficient multiplication circuits 22L and 22R is set to 1 and the coefficient K3 of the coefficient multiplication circuits 23L and 23R is set to -1 as shown in FIG. Then, the coefficient K4 of the coefficient multiplying circuits 24L and 24R is set to, for example, １ ／.
[0059]
Therefore, at this time, after the addition of the audio signals La and Ra of the left and right channels composed of the performance components from the addition circuits 27L and 27R and the processing of the virtual stereophonic sound from the virtual stereophonic sound processing unit 30, the addition circuits 43L and 43R. The left and right two-channel audio signals L4 and R4 are added to the selector 41, and the selector 41 outputs the audio signals L4 and R4. Is selected from the selector 41 as output audio signals L5 and R5.
[0060]
Therefore, in the mixed output mode, it is possible to reproduce the performance components of the music obtained as the input audio signals L1 and R1 in the original localized state, and to obtain a virtual stereophonic effect only for the vocal components of the music. Can be.
[0061]
[Second example of specific component extraction and virtual stereophonic processing: FIG. 7]
(Constitution)
As another example, as shown in FIG. 7, the specific component extraction unit 20 includes coefficient multiplication circuits 45L and 45R, an addition circuit 46, a digital filter 47, coefficient multiplication circuits 48L and 48R, and subtraction circuits 49L and 49R. You.
[0062]
The coefficient K5 of the coefficient multiplying circuits 45L and 45R is set to 1. Therefore, a signal obtained by adding the input audio signals L1 and R1 of the left and right two channels at a ratio of 1: 1 is obtained as the output signal of the adding circuit 46.
[0063]
The digital filter 47 extracts a human voice band, for example, a frequency component of 200 Hz to 3 kHz from the output signal of the adding circuit 46. Therefore, a one-channel audio signal C2 composed of vocal components is obtained as an output signal of the digital filter 47.
[0064]
In a virtual stereophonic sound output mode and a mixed output mode, which will be described later, the virtual stereophonic sound processing unit 30 performs virtual stereophonic sound processing on the one-channel audio signal C2 including the vocal components, and performs virtual stereoscopic sound processing. The audio processing unit 30 obtains left and right two-channel audio signals L3 and R3 composed of processed vocal components.
[0065]
On the other hand, the coefficient K6 of the coefficient multiplication circuits 48L and 48R is set by the control unit 70 according to the output mode, and is set to 0 in the normal output mode, and to 1/2 in the karaoke output mode, the virtual stereophonic sound output mode, and the mixed output mode. Is done.
[0066]
Therefore, in the output modes other than the normal output mode, the vocal components of the outputs of the coefficient multiplying circuits 48L and 48R are subtracted from the input audio signals L1 and R1 by the subtracting circuits 49L and 49R, so that the subtracting circuits 49L and 49R perform the subtraction. Performance components in the input audio signals L1 and R1 are extracted as the output signals L2 (La) and R2 (Ra).
[0067]
(Each output mode)
In the normal output mode, the coefficient K6 of the coefficient multiplying circuits 48L and 48R is set to 0, and the input audio signals L1 and R1 of the left and right channels are directly used as the audio signals L2 and R2 through the subtracting circuits 49L and 49R. When the selector 41 is switched to a state of selecting the audio signals L2 and R2, the selector 41 obtains output audio signals L5 and R5 from the selector 41.
[0068]
In the karaoke output mode, the coefficient K6 of the coefficient multiplying circuits 48L and 48R is set to 1/2, and the left and right two-channel audio signals composed of the performance components from the subtracting circuits 49L and 49R are converted into the audio signals L2 and R2. Is supplied to the selector 41, and at this time, the selector 41 is switched to a state of selecting the audio signals L2 and R2, so that the selector 41 obtains the output audio signals L5 and R5.
[0069]
In the virtual stereophonic sound output mode, the left and right two-channel audio signals L3 and R3 composed of the vocal components after the processing of the virtual stereophonic sound from the above-described virtual stereophonic sound processing unit 30 are supplied to the selector 41. Are switched to a state in which the audio signals L3 and R3 are selected, and are obtained from the selector 41 as output audio signals L5 and R5.
[0070]
In the mixed output mode, the coefficient K6 of the coefficient multiplying circuits 48L and 48R is set to 1/2. Therefore, at this time, the addition circuits 43L and 43R use the left and right two-channel audio signals La (L2) and Ra (R2) composed of the performance components from the subtraction circuits 49L and 49R, respectively, and the virtual stereophonic processing unit described above. The left and right two-channel audio signals L3 and R3 composed of the vocal components after the processing of the virtual stereophonic sound from S30 are added, and the added left and right two-channel audio signals L4 and R4 are supplied to the selector 41. At this time, when the selector 41 is switched to a state of selecting the audio signals L4 and R4, the selector 41 obtains the output audio signals L5 and R5 from the selector 41.
[0071]
[Third example of specific component extraction and virtual stereophonic processing: FIG. 8]
In the embodiment of FIG. 1 and the first and second examples described above, a vocal component is extracted from left and right two-channel input audio signals L1 and R1, and a virtual stereophonic sound is generated as a one-channel audio signal C2 including the vocal component. In this case, the left and right two-channel input audio signals L1 and R1 are converted into one channel in the reverse order by performing the processing to obtain the left and right two-channel audio signals L3 and R3 including the vocal components after the processing of the virtual stereophonic sound. The audio signal of one channel may be subjected to virtual stereophonic sound processing to obtain audio signals of left and right two channels after the processing of the virtual stereophonic sound, and a vocal component may be extracted from the audio signal.
[0072]
FIG. 8 shows an example in this case. In this example, the left and right two-channel input audio signals L1 and R1 are converted into one channel by the signal synthesis unit 90.
[0073]
That is, the signal synthesizing unit 90 includes coefficient multiplying circuits 91L and 91R and an adding circuit 92. The coefficients of the coefficient multiplying circuits 91L and 91R are set to the same coefficient value as indicated by K7. The left and right two-channel input audio signals L1 and R1 are added at 1: 1 to obtain a one-channel input audio signal as the output signal C7 of the signal synthesis unit 90.
[0074]
In this example, the virtual stereophonic sound processing unit 30 performs virtual stereophonic sound processing on the input audio signal C7 that has been converted into one channel. Audio signals L7 and R7 are obtained.
[0075]
The virtual stereophonic sound processing itself in the virtual stereophonic sound processing unit 30 is the same as the above-described respective examples, and is different from the above-described respective examples in that the processing target and the processed audio signal do not include only vocal components.
[0076]
In this example, the digital filters 95L and 95R extract a human voice band, for example, a frequency component of 200 Hz to 3 kHz in the left and right two-channel audio signals L7 and R7 after the processing of the virtual stereophonic sound. . Therefore, the left and right two-channel audio signals L3 and R3 composed of the vocal components after the processing of the virtual stereophonic sound are obtained from the digital filters 95L and 95R.
[0077]
Also in this example, the left and right two-channel audio signals including the vocal components after the processing of the virtual stereophonic sound are selected so that any one of the normal output, the karaoke output, the virtual stereophonic sound output, and the mixed output can be selected. L3 and R3 are supplied to the selector 41.
[0078]
On the other hand, in this example, the specific component extracting unit 20 does not include the coefficient multiplying circuits 24L and 24R and the adding circuit 29 for outputting virtual stereophonic sound in the specific component extracting unit 20 in FIG. That is, it is configured to include coefficient multiplication circuits 21L, 21R, 22L, 22R, 23L, 23R, digital filters 25L, 25R, and addition circuits 26, 27L, 27R, 28L, 28R.
[0079]
Therefore, in the normal output mode, similarly to the mode shown in FIG. 3, the input audio signals L1 and R1 of the left and right channels are obtained as they are from the specific component extraction unit 20 as the audio signals L2 and R2, and the selector 41 At this time, the selector 41 is switched to a state of selecting the audio signals L2 and R2, and is thus obtained as output audio signals L5 and R5 from the selector 41.
[0080]
In the karaoke output mode, similarly to the mode shown in FIG. 4, the performance components in the left and right two-channel input audio signals L1 and R1 are obtained from the specific component extraction unit 20 as the audio signals L2 and R2, and the selector 41 At this time, the selector 41 is switched to a state of selecting the audio signals L2 and R2, and is thus obtained as output audio signals L5 and R5 from the selector 41.
[0081]
In the virtual stereophonic sound output mode, the left and right two-channel audio signals L3 and R3 composed of the vocal components after the processing of the virtual stereophonic sound obtained from the digital filters 95L and 95R are supplied to the selector 41. When 41 is switched to a state of selecting the audio signals L3 and R3, it is obtained from the selector 41 as output audio signals L5 and R5.
[0082]
In the mixed output mode, the performance components in the left and right two-channel input audio signals L1 and R1 are obtained as audio signals La and Ra from the specific component extraction unit 20, and are formed by the addition circuits 43L and 43R. Left and right two-channel audio signals La and Ra are added to left and right two-channel audio signals L3 and R3 composed of vocal components after virtual stereophonic sound processing from digital filters 95L and 95R, and the left and right two channels after the addition are added. Are supplied to the selector 41. At this time, the selector 41 is switched to a state of selecting the audio signal L4, R4, and is obtained from the selector 41 as output audio signals L5, R5.
[0083]
[Other embodiments]
The specific component obtained as the output audio signal after the processing of the virtual stereophonic sound is not limited to the vocal component, but may be any component that can be extracted according to the localization state or the frequency band.
[0084]
When reproducing the output audio signal, the reproduction is not limited to the speaker, but may be performed using headphones or the like.
[0085]
When the output audio signal is recorded on a recording medium, it can be recorded not only on a hard disk but also on an optical disk, a magneto-optical disk, a memory card, or the like.
[0086]
In the above-described embodiment, the input audio signal to be processed is reproduced from the optical disk. However, the present invention is applicable to the case where the input audio signal to be processed is reproduced from a recording medium such as a magneto-optical disk or a semiconductor memory. Can also be applied.
[0087]
The present invention can be applied not only to the case where the input audio signal is reproduced from the recording medium as described above, but also to the case where the input audio signal is received through a broadcast or a communication network.
[0088]
Further, even when the input audio signal is an analog audio signal, the present invention can be applied by converting the analog audio signal into a digital audio signal.
[0089]
【The invention's effect】
As described above, according to the present invention, it is possible to obtain a virtual stereophonic effect only for a specific component such as a reproduced or received music.
[Brief description of the drawings]
FIG. 1 is a diagram showing one embodiment of a digital audio processing device of the present invention.
FIG. 2 is a diagram illustrating a first example of specific component extraction and virtual stereophonic sound processing.
FIG. 3 is a diagram showing a normal output mode of the first example.
FIG. 4 is a diagram showing a karaoke output mode of the first example.
FIG. 5 is a diagram showing a virtual stereophonic sound output mode of the first example.
FIG. 6 is a diagram showing a mixed output mode of the first example.
FIG. 7 is a diagram illustrating a second example of specific component extraction and virtual stereophonic processing.
FIG. 8 is a diagram illustrating a third example of specific component extraction and virtual stereophonic processing.
[Explanation of symbols]
Since the main parts are all described in the figure, they are omitted here.

Claims (13)

By localization state or frequency band of each component in the input digital audio signal, extracting a specific component of the input digital audio signal,
Subjecting the extracted specific component to virtual stereophonic sound processing to obtain an output digital audio signal;
A digital audio processing method comprising: Performing virtual stereophonic sound processing on the input digital audio signal;
Extracting a specific frequency component from the processed digital audio signal to obtain an output digital audio signal;
A digital audio processing method comprising: The digital audio processing method according to claim 1 or 2,
Converting the output digital audio signal into an analog audio signal and reproducing the audio signal;
In the virtual stereophonic sound processing step, a digital audio processing method for dynamically performing virtual stereophonic sound processing on a specific component to be processed or an input digital audio signal. The digital audio processing method according to any one of claims 1 to 3,
A digital audio processing method comprising a step of recording the output digital audio signal on a recording medium. A digital audio recording medium on which a digital audio signal is recorded by the digital audio processing method according to claim 4. Means for extracting a specific component of the input digital audio signal by the localization state or frequency band of each component in the input digital audio signal,
Means for subjecting the extracted specific component to virtual stereophonic sound processing to obtain an output digital audio signal;
Digital audio processing device comprising: Means for extracting a specific component of the input digital audio signal as a first specific component according to a localization state or a frequency band of each component in the input digital audio signal;
Means for subjecting the extracted first specific component to virtual stereophonic sound processing to obtain a first digital audio signal;
A specific component different from the first specific component of the input digital audio signal is extracted as a second specific component according to a localization state or a frequency band of each component in the input digital audio signal, and a second digital audio signal is extracted. Means for obtaining a signal;
Means for selecting one of the first and second digital audio signals as an output digital audio signal;
Digital audio processing device comprising: Means for extracting a specific component of the input digital audio signal as a first specific component according to a localization state or a frequency band of each component in the input digital audio signal;
Means for subjecting the extracted first specific component to virtual stereophonic sound processing to obtain a first digital audio signal;
A specific component different from the first specific component of the input digital audio signal is extracted as a second specific component according to a localization state or a frequency band of each component in the input digital audio signal, and a second digital audio signal is extracted. Means for obtaining a signal;
Means for combining the first and second digital audio signals to obtain an output digital audio signal;
Digital audio processing device comprising: Means for performing virtual stereophonic sound processing on the input digital audio signal;
Means for extracting a specific frequency component from the processed digital audio signal to obtain an output digital audio signal;
Digital audio processing device comprising: Means for performing virtual stereophonic sound processing on the input digital audio signal;
Means for extracting a specific frequency component as a first specific component from the digital audio signal after the processing to obtain a first digital audio signal;
A specific component different from the first specific component of the input digital audio signal is extracted as a second specific component according to a localization state or a frequency band of each component in the input digital audio signal, and a second digital audio signal is extracted. Means for obtaining a signal;
Means for selecting one of the first and second digital audio signals as an output digital audio signal;
Digital audio processing device comprising: Means for performing virtual stereophonic sound processing on the input digital audio signal;
Means for extracting a specific frequency component as a first specific component from the digital audio signal after the processing to obtain a first digital audio signal;
A specific component different from the first specific component of the input digital audio signal is extracted as a second specific component according to a localization state or a frequency band of each component in the input digital audio signal, and a second digital audio signal is extracted. Means for obtaining a signal;
Means for combining the first and second digital audio signals to obtain an output digital audio signal;
Digital audio processing device comprising: The digital audio processing device according to any one of claims 6 to 11,
Means for converting the output digital audio signal into an analog audio signal and reproducing the signal;
A digital audio processing device, wherein the virtual stereophonic sound processing means dynamically performs virtual stereophonic sound processing on a specific component to be processed or an input digital audio signal. The digital audio processing device according to any one of claims 6 to 12,
A digital audio processing device comprising means for recording the output digital audio signal on a recording medium.

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