JPH1118199A - Acoustic processor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a presence by providing an acoustic processing part for generating the higher harmonic components of plural orders, based on surround channel signals generated in a matrix decoder, adding them to the surround channel signals and outputting them. SOLUTION: For inputted surround-channel signals, the surround-channel signals provided with secondary higher harmonic components are generated in a first multiplier 101, a signal level is adjusted in a first coefficient multiplier 102, and then they are outputted to a first adder 105. In the meantime, the surround-channel signals provided with ternary harmonic components are generated in a second multiplier 103, the signal level is adjusted in a second coefficient multiplier 104, and they are outputted to the first adder 105. After both signals are added in the first adder 105, the signals equal to or below 7 kHz are removed in a first HPF 106, and they are outputted to a second adder 107. They are added to the original surround-channel signals in the second adder 107, branched into the surround-channel signals for left and right speakers and then outputted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an audio processing apparatus in a video and audio reproduction system capable of providing a sense of reality.

[0002]

2. Description of the Related Art Conventionally, when enjoying a movie or the like at home, terrestrial broadcasting such as television broadcasting has been the mainstream. You can enjoy the sound as it is. Some of the video tapes, video discs, satellite broadcasts, etc. that can be enjoyed with these original sounds use an encoding method that performs matrix processing on audio signals of multiple channels and converts them into audio signals of two channels. There is.

A two-channel sound signal encoded using the above-described matrix processing can enjoy sound by stereo reproduction. Further, when a dedicated decoder is used, a four-channel audio signal of left, center, right, and surround is restored from a two-channel audio signal, and four-channel reproduction is performed.
You can enjoy a more realistic sound. These four
Of the audio signals of the channel, the center channel signal plays a role of obtaining clarity and clear localization of the dialogue, and the surround channel signal includes moving sound, environmental sound,
It plays a role of enhancing the sense of presence due to reverberation and the like.

[0004] Surround sound reproduced from a surround channel signal is roughly classified into moving sound, environmental sound, and reverberant sound. The moving sound is used when the sound moves from front to back of the viewer or from back to front of the viewer. The environmental sound is used for creating an atmosphere of the scene, such as a wind sound or a noise of a crowd. Reverberation is used to represent a space such as a hall or a cave. In order to obtain the above-described effects, it is desirable that the moving sound is located behind the viewer, that the sound quality does not change when the sound moves, and that the environmental sound and the reverberant sound are
It is desirable that the sound is not localized in a specific place, spreads naturally throughout the space, and can be heard separately from the sound ahead.

FIG. 9 is a schematic diagram showing a schematic configuration of a conventional video and audio reproduction system. As shown in FIG. 9, a video and audio reproduction system capable of enjoying sound by using video and four-channel audio signals is a signal supply device 901,
Sound processing device 902, amplification device 903, monitor 904,
Left speaker 905a, center speaker 905b,
Light speaker 905c, surround speaker 905d
And

[0006] A signal supply device 901 obtains signals from a video tape, a video disk, a satellite broadcast or the like, reproduces a video signal and an audio signal, and supplies them to respective devices. The video signal is supplied to a monitor 904, and the two-channel audio signal is supplied to a dedicated matrix decoder 906 of the audio processing device 902. The matrix decoder 906 includes:
Left channel (L channel) from two audio signals
A signal, a center channel (C channel) signal, a right channel (R channel) signal, and a surround channel (S channel) signal are generated, and the amplification device 903 is generated.
Output to After amplifying the signal, the amplifying device 903 respectively outputs a left speaker 905a and a center speaker 90.
5b, light speaker 905c, surround speaker 9
05d.

[0007] From each speaker, an audio signal corresponding to the arrangement is output, so that the viewer can obtain a sense of realism.

[0008]

However, among the above-described four-channel audio signals, the S-channel signal for the surround speaker 905d disposed behind the viewer is intended to improve crosstalk with other channel signals. Therefore, it is a signal from which a signal in a frequency band of 7 KHz or more has been removed.

That is, the two-channel audio signals AR and AL are subjected to matrix processing by the matrix decoder 906, and are converted into four-channel audio signals of a right channel signal, a center channel signal, a left channel signal, and a surround channel signal. . In the four-channel audio signal, the center channel signal is distributed to the right channel signal and the left channel signal in the same phase, and the surround channel signal is distributed to the right channel signal and the left channel signal in the opposite phase.

For this reason, the left channel signal and the right channel signal, and the center channel signal and the surround channel signal, which are opposed to each other, have infinite separation. However, in the sum signal generation processing and the difference signal generation processing in the matrix processing, for example, , A left channel and a surround channel, or a right channel and a surround channel.

In order to improve the crosstalk between channels, a surround channel signal is subjected to a low-pass filter processing to remove a high frequency component signal.
It is a surround channel signal having a frequency component of z or less. However, at present, video and audio reproduction systems and the like using five-channel audio signals have begun to become widespread. Compared with such systems, systems using surround channel signals of low-frequency components have more environmental and reverberant sounds. However, there is a disadvantage in that the sense of presence such as the feeling of spreading of the sound and the feeling of movement of the sound image is lost.

In a video and audio reproduction system using four-channel audio signals, only one surround speaker 905d is provided behind the viewer, and the surround channel signal is a monaural signal. Compared to a video and audio reproduction system using a signal, there is a disadvantage that a sense of presence such as a sense of sound spread is impaired.

Therefore, the present invention relates to an audio processing apparatus in a video / audio reproduction system capable of obtaining a sense of realism, wherein the sound processing apparatus can obtain a sense of realism by using a pseudo stereo surround channel signal having an expanded frequency band. It is intended to provide.

[0014]

Therefore, according to the present invention, a two-channel audio signal generated by subjecting a plurality of audio signals to a matrix process is provided.
In a sound processing device capable of restoring audio signals of a plurality of channels, a matrix decoder for generating at least a right channel signal, a left channel signal, a center channel signal, and a surround channel signal from a two-channel audio signal, and a matrix decoder And a sound processing unit that generates a plurality of harmonic components of a plurality of orders based on the obtained surround channel signal, adds the generated harmonic component to the surround channel signal, and outputs the resultant.

According to a second aspect of the present invention, there is provided an audio processing apparatus capable of restoring a plurality of audio signals from a two-channel audio signal generated by subjecting a plurality of audio signals to matrix processing. A matrix decoder that generates at least a right channel signal, a left channel signal, a center channel signal, and a surround channel signal from the two-channel acoustic signal; and a plurality of harmonic components of a plurality of orders based on the surround channel signal generated by the matrix decoder. The sound processing unit further includes a sound processing unit that adds harmonic components having different signal levels depending on the order to the surround channel signal to generate and output a plurality of different surround channel signals.

According to a third aspect of the present invention, there is provided an audio processing apparatus capable of restoring a plurality of audio signals from a two-channel audio signal generated by subjecting a plurality of audio signals to matrix processing. A matrix decoder that generates at least a right channel signal, a left channel signal, a center channel signal and a surround channel signal from the channel acoustic signal, and a plurality of harmonic components based on the surround channel signal generated by the matrix decoder are generated. A sound processing unit that generates and outputs a first surround channel signal obtained by adding an odd-order harmonic component to a surround channel signal and a second surround channel signal obtained by adding an even-order harmonic component to a surround channel signal; It is characterized in that.

According to the present invention, a plurality of orders based on a low frequency component surround channel signal among at least a right channel signal, a left channel signal, a center channel signal, and a surround channel signal generated from a two-channel audio signal. Can be added and the generated harmonic component and the surround channel signal can be added and output, so that a sense of realism such as a feeling of spreading of environmental sounds and reverberant sounds and a feeling of movement of a sound image can be obtained. be able to.

Further, according to the present invention, a plurality of at least a right channel signal, a left channel signal, a center channel signal, and a surround channel signal generated from a two-channel audio signal based on a low frequency component surround channel signal. It is possible to generate harmonic components of the following order, add the generated harmonic components to the surround channel signal at different signal levels depending on the order, and generate and output a plurality of different surround channel signals separately. By generating a pseudo stereo surround channel signal from one surround channel signal, it is possible to obtain a more realistic feeling.

Further, according to the present invention, a plurality of at least a right channel signal, a left channel signal, a center channel signal, and a surround channel signal generated from a two-channel audio signal based on a low frequency component surround channel signal are used. And a harmonic component of an odd order among the generated harmonic components is added to the surround channel signal to generate a first surround channel signal. Also, a harmonic component of an even order is generated. Can be added to the surround channel signal to generate a second surround channel signal, and these surround channel signals can be output separately. Therefore, a pseudo stereo surround channel signal can be generated from one surround channel signal. Get more realism Door can be.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A sound processing apparatus according to the present invention will be described. The sound processing device includes a matrix decoder and a sound processing unit. First, a schematic configuration of the sound processing unit will be described. FIG. 1 is a schematic diagram showing a schematic configuration of one embodiment of a sound processing unit in a sound processing device of the present invention. In FIG. 1, a sound processing unit includes a first multiplier 101, a first coefficient multiplier 102, a second multiplier 103, and a second coefficient multiplier 1.
04, a first adder 105, a first high-pass filter (HPF) 106, a second adder 10
7 is provided.

FIG. 2 is a schematic diagram for explaining a surround channel signal in the sound processing section of the present embodiment. Here, in FIG. 2, a signal of a harmonic component described later has an upper limit of about 22 KHz, which is a human audible range, and a higher harmonic component of 22 KHz or more is removed by a digital filter or the like (not shown).

In FIG. 1, the audio signal input to the acoustic processing unit is a surround channel signal (surround signal) generated by a matrix decoder.
As shown in FIG. 2A, the audio signal has a frequency component of 7 KHz or less. The input surround channel signal is divided into a first multiplier 101 and a second multiplier 10.
3 is input.

The first multiplier 101 squares the input surround channel signal and outputs the result to the first coefficient multiplier 102 and the second multiplier 103. When the input surround channel signal is represented by cosωt, the first multiplier 101
Is given by: cosωt * cosωt = (1 + cos2ωt) / 2 (1), and a second harmonic component of the input surround channel signal is generated. Therefore, the first multiplier 101
Generates a surround channel signal having the second harmonic component shown in FIG.
Multiplies the surround channel signal by a coefficient K1, adjusts the signal level, and outputs the signal to the first adder 105.

The second multiplier 103 multiplies the input surround channel signal by the signal output from the first multiplier 101 and outputs the result to the second coefficient multiplier 104. When the input surround channel signal is indicated by cosωt, the signal output from the second multiplier 103 is expressed as cosωt * cosωt * cosωt = {(3cosωt) + (cos3ωt)} / 4 (2) A third harmonic component of the channel signal is generated. Therefore, the second multiplier 103
Then, a surround channel signal having the third harmonic component shown in FIG. 2C is generated, and the second coefficient multiplier 104
Multiplies the surround channel signal by a coefficient K2, adjusts the signal level, and outputs the signal to the first adder 105.

The first adder 105 includes a first coefficient multiplier 10
The surround channel signal having the second harmonic component output from 2 and the surround channel signal having the third harmonic component output from the second coefficient multiplier 104 are added and output to the first HPF 106.

The signal output from the first adder 105 is
This is a signal having an original surround channel signal having a frequency component of 7 KHz or less, and a second harmonic component and a third harmonic component generated based on the original surround channel signal. The second-order harmonic component and the third-order harmonic component generated by the first multiplier 101 and the second multiplier 103 are also generated for a signal having a frequency component of 7 KHz or less of the surround channel signal. For example, if the fundamental wave is 1 KHz, a second harmonic signal is generated at 2 KHz, a third harmonic signal is generated at 3 KHz, and if the fundamental wave is 2 KHz, 2 harmonics are generated at 4 KHz.
A third harmonic signal is generated at 8 KHz.

Then, the second harmonic component generated by the first multiplier 101 and the first coefficient multiplier 102 includes the second harmonic component of 7 KHz or less which is not included in the original surround channel signal. The third harmonic component generated by the second multiplier 103 and the second coefficient multiplier 104 includes a third harmonic component of 7 KHz or less that is not included in the original surround channel signal, and has a different sound quality from the original surround channel signal. It becomes a surround channel signal. Therefore, after the respective signals are added by the first adder 105, the first H
The PF 106 removes a signal of 7 KHz or less corresponding to the frequency component of the original surround channel signal.
As shown in (d), only the second harmonic component and the third harmonic component are output to the second adder 107.

As shown in FIG. 2E, the second adder 107 adds the second and third harmonic components output from the first HPF 106 to the original surround channel signal having a frequency component of 7 KHz or less. Are added, and then the signal is branched into a surround signal for a left speaker (L speaker) and a surround signal for a right speaker (R speaker) and output. That is, a surround channel signal having a frequency band up to about 22 kHz is generated by generating and adding a second harmonic component and a third harmonic component to the surround channel signal having a frequency component of 7 kHz or less and the surround channel signal. Can be generated and output.

A video / audio reproduction system using the audio processing apparatus having the above-mentioned audio processing unit will be described. FIG. 3 is a schematic diagram showing a schematic configuration of an embodiment of a video and audio reproduction system using the audio processing device of the present invention. FIG.
In the video / audio reproduction system, the signal supply device 30
1, an acoustic processing device 302, and an amplifying device 303. The reproduced video signal and audio signal were output from a monitor 304 disposed in front of the viewer, and the audio signal was converted to an audio signal and then disposed around the viewer. Left speaker 305
a, center speaker 305b, light speaker 305
c, output from the surround speaker 305d.

The signal supply device 301 reproduces a video signal and an audio signal from a signal transmitted by a radio wave or the like or a signal reproduced from a disk, a tape, or the like, and outputs the video signal and the audio signal for writing (AL). And a left audio signal (AL).

The video signal is input to the monitor 304 and output as a still image or a moving image.

The sound signals AR and AL are output from the sound processor 3
02 is input to the matrix decoder 306. The matrix decoder 306 performs a matrix operation on the audio signals AR and AL to execute a light channel (R channel) signal for the light speaker 305c and the center speaker 3
05b center channel (C channel) signal,
Left channel (L channel) signal for left speaker 305a, 7KH for surround speaker 305d
A surround channel (S channel) signal having a frequency component equal to or lower than z is generated.

The right channel signal, the center channel signal, and the left channel signal are output to the amplifying device 303, and the surround channel signal is output to the sound processing unit 3.
07. As described above, the acoustic processing unit 307 generates and adds the second harmonic component and the third harmonic component based on the surround channel signal having the frequency component of 7 KHz or less, and has a frequency band up to about 22 KHz. A surround channel signal is generated, branched into two, and output to the amplifier 303.

The amplifying device 303 amplifies the input right channel signal, center channel signal, left channel signal, and surround channel signal, and outputs a right speaker 305c and a center speaker 305, respectively.
b, left speaker 305a and surround speaker 3
05d. Here, the amplifying device 303 controls the sound processing unit 3 in the surround channel signal input from the matrix decoder 306 via the sound processing unit 307.
The processing time of the right channel signal, the center channel signal, and the left channel signal input directly from the matrix decoder 306 is output in consideration of the processing time of 07.

Therefore, the viewer can use the left speaker 3
05a, a powerful sound can be heard from the center speaker 305b and the light speaker 305c,
From the surround speakers 305d arranged behind,
The user can listen to the surround sound whose frequency band has been expanded, and can obtain a sense of presence such as a sense of spread of the environmental sound and the reverberant sound and a sense of movement of the sound image.

In the above-described video / audio reproduction system,
A description will be given of a video and audio reproduction system that can obtain a sense of realism by expanding the frequency band of the surround channel signal, but can further obtain a sense of realism. That is, the above-described surround channel signal is obtained by expanding the frequency band of the originally monaural sound channel signal, dividing the monaural sound into two,
Are output from the surround speakers.

7K generated by the matrix decoder
A surround channel signal having a frequency band up to about 22 KHz is generated from a surround channel signal having a frequency component of less than or equal to Hz, and a surround channel signal for a pseudo right channel and a left channel is generated from the surround channel signal. The sound processing unit will be described.

FIG. 4 is a schematic diagram showing a schematic configuration of another embodiment of the sound processing section in the sound processing apparatus of the present invention.
In FIG. 4, the acoustic processing unit includes a first multiplier 401, a first multiplier 401,
Coefficient multiplier 402, second multiplier 403, second coefficient multiplier 404, first adder 405, first HPF 406, second adder 407, second HPF 408, third adder 409, third HPF 410, fourth adder 411 And

FIG. 5 is a schematic diagram for explaining a surround channel signal in the sound processing unit of this embodiment. Here, in FIG. 5, a signal of a harmonic component described later has an upper limit of about 22 KHz, which is a human audible range, and a higher harmonic component of 22 KHz or more is removed by a digital filter or the like (not shown).

In FIG. 4, the signal input to the acoustic processing unit is a surround channel signal having a frequency component of 7 KHz or less generated by a matrix decoder as shown in FIG. Input to the second multiplier 403.

The first multiplier 401 squares the input surround channel signal and outputs the result to the first coefficient multiplier 402 and the second multiplier 403. When the input surround channel signal is represented by cosωt, the first multiplier 401
Is given by cosωt * cosωt = (1 + cos2ωt) / 2 (3), and a second harmonic component of the input surround channel signal is generated. Therefore, the first multiplier 401
Then, a surround channel signal having a second harmonic component is generated, and the first coefficient multiplier 402 multiplies the surround channel signal by a coefficient K1, adjusts the signal level, and outputs the signal to the first adder 405. .

The second multiplier 403 multiplies the input surround channel signal by the signal output from the first multiplier 401 and outputs the result to the second coefficient multiplier 404. When the input surround channel signal is represented by cosωt, the signal output from the second multiplier 403 is: cosωt * cosωt * cosωt = {(3cosωt) + (cos3ωt)} / 4 (4) A third harmonic component of the channel signal is generated. Therefore, the second multiplier 403
Then, a surround channel signal having a third harmonic component is generated. The second coefficient multiplier 404 multiplies the surround channel signal by a coefficient K2, adjusts the signal level, and outputs the signal to the first adder 405. .

The first adder 405 is connected to the first coefficient multiplier 40
The surround channel signal having the second harmonic component output from 2 and the surround channel signal having the third harmonic component output from the second coefficient multiplier 404 are added and output to the first HPF 406.

The signal added by the first adder 405 is a surround channel signal having a frequency component of 7 KHz or less, and a signal of a second harmonic component and a signal of a third harmonic component generated based on the original surround channel signal. It is. That is, a surround channel signal having a frequency band up to about 22 KHz as shown in FIG.

On the other hand, the surround channel signal having the second harmonic component input from the first coefficient multiplier 402 to the second HPF 408 is
The signal of the frequency component below KHz is removed, and FIG.
, Only the second harmonic component having a frequency band from 7 KHz to 14 KHz is output to the third adder 409.

Also, the surround channel signal having the third harmonic component input from the second coefficient multiplier 404 to the third HPF 410 is converted by the third HPF 410 into one.
The signal of the frequency component of 4 KHz or less is removed, and FIG.
Only the third harmonic component having a frequency band from 14 KHz to 22 KHz as shown in FIG.
11 is output.

The third adder 409 adds the second HPF 408 to the surround channel signal output from the second adder 407 and having a frequency band up to about 22 KHz.
The second harmonic component having a frequency band between 7 KHz and 14 KHz, which is output from, is added. Then, as shown in FIG. 5E, a surround channel signal having a frequency band up to about 22 KHz and an increased signal level in a frequency band from 7 KHz to 14 KHz is generated. This signal is output as a surround channel signal for the right channel.

Further, the fourth adder 411 is provided with the second adder 4.
A third harmonic component having a frequency band from 14 KHz to 22 KHz output from the third HPF 410 is added to the surround channel signal having a frequency band from about 07 to about 22 KHz. Then, as shown in FIG. 5F, a surround channel signal having a frequency band up to about 22 KHz and an increased signal level in a frequency band from 14 KHz to 22 KHz is generated. This signal is output as a surround channel signal for the left channel.

That is, from a monaural surround channel signal having a frequency component of 7 KHz or less, about 22 KHz
It is possible to generate a surround channel signal for a right channel and a surround channel signal for a left channel having frequency bands up to and having different frequency characteristics. The surround channel signal for the right channel and the surround channel signal for the left channel have different frequency characteristics due to an increase in the signal level of a specific frequency band, so that the viewer hears different sounds and feels stereo. Can be obtained.

The above-described embodiment will be specifically described with reference to FIGS. FIG. 6 is a schematic diagram for explaining a stereo surround channel signal in the sound processing unit of the present embodiment. As shown in FIG. 6A, the surround channel signal input to the sound processing unit is 7 KH
This is an audio signal of a monaural sound having a frequency component of z or less. First, as described above, the first multiplier 401, the first coefficient multiplier 402, the second multiplier 403, and the second coefficient multiplier 4
04, the first adder 405, the first HPF 406, and the second adder 407, as shown in FIG.
A surround channel signal having a frequency band up to Hz is generated. In the audio signal, a component having a high signal level exists in a low band, and the signal level decreases as the frequency increases.

On the other hand, in the second HPF 408, FIG.
As shown in (c), only the second harmonic component generated by the first multiplier 401 and the first coefficient multiplier 402 is extracted. In the third HPF 410, as shown in FIG. 6D, the second multiplier 403 and the second coefficient multiplier 40
Only the third harmonic component generated in step 4 is extracted.

Then, the third adder 409 adds the surround channel signal having a frequency band up to about 22 KHz from the second adder 407 and the second harmonic component from the second HPF 408, and FIG. As shown,
A surround channel signal for a light channel can be obtained. That is, for a surround channel signal having a frequency band up to about 22 KHz, 7 KHz
Thus, a surround channel signal having a frequency characteristic with an increased signal level of 14 KHz can be obtained.

The fourth adder 411 outputs a surround channel signal having a frequency band of up to about 22 KHz from the second adder 407 and a third channel signal from the third HPF 410.
The higher harmonic components are added to obtain a surround channel signal for the left channel as shown in FIG. That is, for a surround channel signal having a frequency band up to about 22 KHz,
Thus, a surround channel signal having a frequency characteristic with an increased signal level of 22 KHz can be obtained.

Therefore, the viewer hears the surround channel signal for the right channel having the frequency characteristic shown in FIG. 6E and the surround channel signal for the left channel having the frequency characteristic shown in FIG. Due to different frequency characteristics, they are perceived as acoustic signals of different sound quality. That is, since the surround sound output from the two surround speakers can be heard as different sounds, the viewer can obtain a pseudo stereo feeling, and can obtain more realistic sound.

Here, any of the above-described surround channel signals having different frequency characteristics may be selected as a surround channel signal for the left channel or a surround channel signal for the right channel. The order of the harmonic components is not limited to the second or third order, and higher order harmonic components may be generated.

Another embodiment for generating a surround channel signal capable of obtaining a pseudo stereo sound from a surround channel signal having a frequency component of 7 KHz or less will be described. FIG. 7 is a schematic diagram showing a schematic configuration of another embodiment of the sound processing unit in the sound processing device of the present invention. In FIG. 7, the sound processing unit includes a first multiplier 7
01, second multiplier 702, third multiplier 703, fourth multiplier 704, first coefficient multiplier 705, second coefficient multiplier 70
6, third coefficient multiplier 707, fourth coefficient multiplier 708, first adder 709, second adder 710, first HPF 71
1, a second HPF 712, a third adder 713, and a fourth adder 714.

FIG. 8 is a schematic diagram for explaining a surround channel signal in the sound processing section of this embodiment. Here, in FIG. 8, a signal of a harmonic component, which will be described later, has an upper limit of about 22 KHz, which is a human audible range, and a higher harmonic component of 22 KHz or more is removed by a digital filter or the like (not shown).

In FIG. 7, the surround channel signal generated by the matrix decoder is an audio signal having a frequency component of 7 KHz or less as shown in FIG. 8A, and includes a first multiplier 701, a second multiplier 702, The signal is input to the third multiplier 703 and the fourth multiplier 704.

The first multiplier 701 squares the input surround channel signal to generate a second harmonic component,
Output to the first coefficient multiplier 705 and the second multiplier 702.
The first coefficient multiplier 705 multiplies the surround channel signal by a coefficient K1, adjusts the signal level, and
Output to the adder 709.

The second multiplier 702 multiplies the input surround channel signal by the signal output from the first multiplier 701 to generate a third harmonic component, and the second multiplier 706 and the third multiplier 706 Output to the device 703. The second coefficient multiplier 706 multiplies the surround channel signal by a coefficient K2, adjusts the signal level, and outputs the signal to the second adder 710.

The third multiplier 703 multiplies the input surround channel signal by the signal output from the second multiplier 702 to generate a fourth harmonic component, and the third multiplier 707 multiplies the fourth multiplier by the fourth multiplier. Output to the device 704. The third coefficient multiplier 707 multiplies the surround channel signal by a coefficient K3, adjusts the signal level, and outputs the signal to the first adder 709.

The fourth multiplier 704 multiplies the input surround channel signal by the signal output from the third multiplier 703 to generate a fifth harmonic component, and outputs the fifth harmonic component to the fourth coefficient multiplier 708. The fourth coefficient multiplier 708 multiplies the surround channel signal by a coefficient K4, adjusts the signal level, and outputs the signal to the second adder 710.

The first adder 709 includes a first coefficient multiplier 70
5 and the surround channel signal having the fourth harmonic component output from the third coefficient multiplier 707 are added to the surround channel signal having the second harmonic component and output to the first HPF 711. First adder 7
09 is a signal having a frequency component of 7 KHz or less, a surround channel signal, a second harmonic component generated based on the original surround channel signal, and 4
This is the signal of the higher harmonic component. 7 by the first HPF 711
By removing signals of frequency components below KHz,
As shown in FIG. 8B, it is possible to obtain a signal of a second harmonic component from 7 KHz to 14 KHz and a signal of a fourth harmonic component of 7 KHz or more.

The second adder 710 combines the surround channel signal having the third harmonic component output from the second coefficient multiplier 706 with the fifth harmonic component output from the fourth coefficient multiplier 708. And the resulting surround channel signal, and outputs the result to the second HPF 712. The signal added by the second adder 710 is a surround channel signal having a frequency component of 7 KHz or less, and a signal of a third harmonic component and a signal of a fifth harmonic component generated based on the original surround channel signal. By removing the signal of the frequency component of 7 KHz or less by the second HPF 712, the signal of the third harmonic component of 7 KHz or more and the signal of the fifth harmonic component of 7 KHz or more as shown in FIG. 8C are obtained. be able to.

The third adder 713 converts the input surround channel signal of the frequency component up to 7 KHz from the 7 KHz output from the first HPF
The signal of the second harmonic component up to KHz and the signal of the fourth harmonic component of 7 KHz or more are added. Then, FIG.
As shown in (d), a surround channel signal having a frequency band up to about 22 KHz and including a second harmonic component and a fourth harmonic component is generated. This signal is output as a surround channel signal for the right channel.

The fourth adder 714 outputs the input 7
A surround channel signal having a frequency component of up to KHz is added to a frequency of 7 KHz or more output from the second HPF 712.
The signal of the fifth harmonic component and the signal of the fifth harmonic component of 7 KHz or more are added. Then, as shown in FIG. 8E, a surround channel signal having a frequency band up to about 22 KHz and including the third harmonic component and the fifth harmonic component is generated. This signal is output as a surround channel signal for the left channel.

That is, from a monaural surround channel signal of 7 KHz or less to a surround channel signal for a light channel having a frequency band up to about 22 KHz and having even-order harmonic components,
And a surround channel signal for a left channel having an odd-order harmonic component. Since the surround channel signal for the right channel and the surround channel signal for the left channel have harmonic components of different orders, the surround sound output from the two surround speakers can be heard as different sounds. A person can obtain a stereo sense in a pseudo manner, and can obtain a sound with a more realistic feeling.

Here, any of the above-mentioned odd-order harmonic component or even-order harmonic component surround channel signal may be selected as the surround channel signal for the left channel or the surround channel signal for the right channel. . Further, the order of the harmonic component is not limited to the second, third, fourth and fifth order, and higher order harmonic components may be generated.

[0069]

According to the present invention, in a sound processing apparatus in a video and audio reproduction system, a sense of reality can be enhanced by a pseudo stereo surround channel signal having an expanded frequency band.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a schematic configuration of one embodiment of a sound processing unit in a sound processing device of the present invention.

FIG. 2 is a schematic diagram for explaining a surround channel signal in an acoustic processing unit according to the embodiment.

FIG. 3 is a schematic diagram showing a schematic configuration of an embodiment of a video and audio reproduction system using the audio processing device of the present invention.

FIG. 4 is a schematic diagram showing a schematic configuration of another embodiment of the sound processing unit in the sound processing device of the present invention.

FIG. 5 is a schematic diagram for explaining a surround channel signal in the acoustic processing unit of the embodiment.

FIG. 6 is a schematic diagram for explaining a stereo surround channel signal in the sound processing unit of the embodiment.

FIG. 7 is a schematic diagram showing a schematic configuration of another embodiment of the sound processing unit in the sound processing device of the present invention.

FIG. 8 is a schematic diagram for explaining a surround channel signal in the sound processing unit of the embodiment.

FIG. 9 is a schematic diagram showing a schematic configuration of a conventional video and audio reproduction system.

[Explanation of symbols]

101 ··· first multiplier, 102 ··· first coefficient multiplier, 1
03 second multiplier, 104 second coefficient multiplier, 10
5 first adder, 106 first HPF, 107
2nd adder 301... Signal supply device, 302... Sound processing device, 3
03 ··· amplification device, 304 · · monitor, 305a · · left speaker, 305b · · · center speaker, 305
c light speaker, 305d surround speaker, 306 matrix decoder, 307 sound processing unit 401 first multiplier, 402 first coefficient multiplier, 4
03 second multiplier, 404 second coefficient multiplier, 40
5 first adder, 406 first HPF, 407
Second adder, 408 second HPF, 409 third adder, 410 third HPF, 411 fourth adder 701 first multiplier, 702 second multiplier, 703
.. A third multiplier, 704 a fourth multiplier, 705 a first coefficient multiplier, 706 a second coefficient multiplier, 707
A third coefficient multiplier, 708... A fourth coefficient multiplier, 709.
.1st adder, 710..2nd adder, 711..first
HPF, 712: second HPF, 713: third adder, 714: fourth adder 901: signal supply device, 902: sound processing device, 9
03 amplifying device, 904 monitor, 905a left speaker, 905b center speaker, 905
c light speaker, 905d surround speaker, 906 matrix decoder

Claims (3)

[Claims] 1. An audio processing apparatus capable of restoring a plurality of audio signals from a two-channel audio signal generated by performing a matrix process on a plurality of audio signals, comprising: A matrix decoder that generates a channel signal, a left channel signal, a center channel signal, and a surround channel signal; a plurality of harmonic components of a plurality of orders based on the surround channel signal generated by the matrix decoder are generated and added to the surround channel signal And a sound processing unit for outputting the sound. 2. An audio processing apparatus capable of restoring a plurality of audio signals from a two-channel audio signal generated by subjecting a plurality of audio signals to a matrix process, comprising: A matrix decoder that generates a channel signal, a left channel signal, a center channel signal, and a surround channel signal; and a plurality of harmonic components of a plurality of orders based on the surround channel signals generated by the matrix decoder. A sound processing unit that adds a harmonic component to the surround channel signal to generate and output a plurality of different surround channel signals. 3. A sound processing apparatus capable of restoring a plurality of channels of audio signals from a two-channel sound signal generated by subjecting a plurality of channels of audio signals to matrix processing, comprising: A matrix decoder that generates a channel signal, a left channel signal, a center channel signal, and a surround channel signal; and a plurality of harmonic components of a plurality of orders based on the surround channel signal generated by the matrix decoder, and a harmonic component of an odd order. Is added to the surround channel signal, and a second surround signal is added to the surround channel signal.
An acoustic processing unit that generates and outputs a surround channel signal.