JPH11146500A - Audio signal playback device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] In a virtual speaker type surround signal processing for obtaining a surround effect only with a front speaker,
It is an object of the present invention to provide an audio signal reproducing device that eliminates the need for input and adjustment of spatial position information by viewers even when the positions of a plurality of viewers are displaced, and obtains a sufficient stereophonic effect while adjusting the viewer settings. I do. SOLUTION: By using a position sensor means 20, a practically sufficient three-dimensional sound effect can be obtained without adjusting a viewer setting related to spatial position information even when a plurality of viewers are in different places.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for decoding a medium on which an encoded recording is made, and then creating a virtual speaker by calculating a head-related transfer function based on the information, and arranging the speaker behind (or laterally). The present invention relates to an audio signal reproducing apparatus having a virtual speaker type surround signal processing for obtaining a surround effect only with a front speaker without using a front speaker.

[0002]

2. Description of the Related Art In recent years, audio signal reproducing apparatuses have become mainstream audiovisual equipment with video such as video tape recorders and DVDs. The number of viewers who enjoy stereophonic sound reproduction using devices including a decoder is increasing. In response to the spread of software and the growing needs of viewers, in order to make ordinary viewers familiar with stereophonic sound reproduction without special awareness, simple connection, simple operation, inexpensive Dolby decoding playback, etc. The realization of surround technology was required. In order to fulfill such a demand, a virtual speaker type surround using an arithmetic technique based on a head-related transfer function has recently been put to practical use.

A conventional audio signal reproducing apparatus will be described below with reference to the drawings. FIG. 3 is a block diagram showing a configuration of a conventional audio signal reproducing device. This conventional audio signal reproducing apparatus, after decoding an encoded and recorded medium, creates a virtual speaker by calculating a head-related transfer function based on the information, and does not arrange a speaker behind (or on the side). Having a virtual speaker type surround signal processing for obtaining a surround effect only with a front speaker,
For example, it is the same as that described in JP-A-5-260597.

In FIG. 3, 1 is an LE input terminal for inputting an audio LE including a surround effect, 2 is an RE input terminal for inputting an audio RE including a surround effect,
4 is a left speaker, 5 is a right speaker, 6 is a virtual center speaker, 7 is a virtual left speaker, 8 is a virtual right speaker, 9 is a virtual left speaker, 10 is a virtual right speaker, 11 is a surround audible range,
12 is the first viewer, 13 is the second viewer, 14 is the third viewer
100, a position input means for actually inputting and listening according to the viewer's sense while varying the spatial coefficient correlated with the viewing center position information, and 101 for a position having a parameter relating to position. Data memory, 102
Is the output of the position input means 100 and the position data memory 1
Effect control means for controlling the effect based on the output of 01, 10
Reference numeral 3 denotes a second virtual signal output to the left speaker 4 and the right speaker 5 by performing a head-related transfer function calculation for obtaining characteristics of a virtual speaker by controlling a filter coefficient that determines a surround effect based on the output of the effect control means 102. Conversion means.

The operation will be described below. First, the position input means 100 actually outputs sound for viewing, and manually inputs the position information of the viewer according to the viewer's feeling while varying the spatial coefficient correlated with the viewing center position information. In the position data memory 101, the position input means 100
Output the parameter corresponding to the output. Effect control means 1
In step 02, parameters for controlling the surround effect of the second virtual signal conversion means 103 are output based on the output of the position input means 100 and the output of the position data memory 101. The second virtual signal conversion means 103 inputs the sound including the surround information from the LE input terminal 1 and the RE input terminal 2 and controls the coefficient of the FIR filter which determines the surround effect based on the output of the effect control means 102 to thereby obtain a plurality of sounds. To the left speaker 4 and the right speaker 5.

[0006] As described above, the best viewing center position is determined, and the virtual speaker is set to be heard so as to correspond to the viewing center position.

Next, the second virtual signal conversion means 103
Will be described with reference to FIG. FIG. 4 is a block diagram showing a configuration of the second virtual signal conversion means 103 in the conventional audio signal reproducing device. 261 and 26
2 is an AD converter for converting an analog signal to a digital signal, 263 and 264 are DA converters for converting a digital signal to an analog signal, and 265 is AD converters 261 and 2
Decoders for decoding the signal including the surround effect input from 62 into L (for the left speaker), R (for the right speaker), C (for the center speaker), and S (for the surround speaker) signals, 266 and 267 are for viewing. Filter that realizes digital processing of the HRTF in the time domain so that the sound is localized at a certain position with respect to the person.
9, 272 and 273 are t1, t1, t2 and t3, respectively.
Delay means 270, 271, 274, 275 for delaying by a sampling period and sounding as if the sound source is far away by a distance determined by the product of these periods and the sound speed are addition means.

The operation will be described below. The signal LE including the surround effect is input from the input terminal 103a, passes through the AD converter 261 and is input to the decoder 265.
The signal RE including the surround effect is input from the input terminal 103b, passes through the AD converter 262, and is input to the decoder 265. These signals are decoded by a decoder 265 into L, R, C and S signals. The signal S branches into two, one passing through an FIR filter 266 and the other a FIR filter 2
Go through 67. The output of the FIR filter 266 branches into two, one of which is input to the adding means 270 and the other is input to the adding means 271 through the delay means 268. FIR filter 26
The seven outputs are branched into two, one of which is input to the adding means 271, and the other is input to the adding means 270 through the delay means 269. The output of the addition means 270 is input to the addition means 274 through the delay means 272. The output of the adding means 271 is input to the adding means 275 through the delay means 273. Signal C is 2
Branching, one is input to the adding means 274 and the other is input to the adding means 275. The signal L is input to the adding means 274. The signal R is input to the adding means 275. Addition means 27
The four outputs are output to the output terminal 103c through the DA converter 263. The output of the adding means 275 is output to the output terminal 103d through the DA converter 264.

[0009]

However, in the above-described conventional configuration, operations such as setting of spatial coefficients and effects remain to reproduce sound including a surround effect. Since the troublesome and delicate adjustment of the spatial parameter remains to adjust the viewing position according to the viewer's own perception and the interval between the two speakers is limited, the surround audible range 11 is narrow, and a plurality of In this case, only the first viewer 12 can obtain the surround effect, so that a sufficient effect cannot be obtained.

[0010] The present invention solves the above-mentioned conventional problems. Even if the position of the viewer is displaced, or if there are a plurality of viewers under general use conditions, the viewer regarding the spatial parameters is not affected. It is possible to obtain a sufficiently large stereophonic effect without any adjustment. Accordingly, it is an object of the present invention to provide an audio signal reproducing apparatus capable of obtaining an inexpensive surround reproduction with a simpler configuration with a simpler operation so that a general viewer can get close to the system without special awareness.

[0011]

In order to achieve the above object, an audio signal reproducing apparatus according to the present invention comprises a position sensor for detecting position information of a plurality of viewers, and an audio signal reproducing device for detecting a position based on an output of the position sensor. An area calculating means for converting and outputting information on the center position and the viewing range, determining whether the information is out of the applicable range, causing an arithmetic error, or being within the applicable range, and outputting a control signal; and a position sensor. A preset data memory for outputting information on a standard viewing center position and a viewing range when the output of the means is not used; an output of the preset data memory and an output of the area calculating means based on a control signal from the area calculating means. Switching means for selecting and outputting, and information on the viewing center position and the viewing range, which are outputs of the switching means, are output as a first output, and an area to be described later corresponding to the first output Effect control means for outputting, as a second output, the optimal parameters for virtual signal conversion in the viewing area based on the output from the data memory; and selecting and outputting a set of spatial parameters based on the first output of the effect control means A head-related transfer function operation for obtaining characteristics of a virtual speaker by controlling a filter coefficient for determining a surround effect based on a second output of an effect control unit by inputting a signal including surround information and an area data memory to perform It has a configuration including first virtual signal conversion means for outputting to the left speaker and the right speaker.

[0012] With this configuration, when a plurality of viewers watch, a confusing viewer does not need to input and adjust spatial position information, and a sufficient stereophonic effect can be obtained under actual use conditions while adjusting the viewer setting. be able to.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION
Position sensor means for detecting position information of a plurality of viewers; converting and outputting information on a viewing center position and a viewing range based on the output of the position sensor means; Area calculating means for judging whether the data is within the applicable range and outputting a control signal, and a preset for outputting information on a standard viewing center position and a viewing range when the output of the position sensor means is not used. Data memory, and switching means for selecting and outputting the output of the preset data memory and the output of the area calculation means based on a control signal from the area calculation means,
The information of the viewing center position and the viewing range output from the switching means is output as a first output, and the virtual signal conversion in the viewing area is performed based on an output from an area data memory described later corresponding to the first output. Effect control means for outputting the optimum parameter of the above as a second output, an area data memory for selecting and outputting a set of spatial parameters based on the first output of the effect control means, and a signal including surround information. A first transfer function for inputting and controlling a filter coefficient for determining a surround effect based on a second output of the effect control means to obtain a characteristic of a virtual speaker, and outputting to a left speaker and a right speaker; Virtual signal conversion means, and a position sensor means for detecting position information of a plurality of viewers. By controlling the first virtual signal conversion means based on the force, it is not necessary to input and adjust spatial position information by a confusing viewer when a plurality of viewers watch, and the actual use is performed without adjusting the viewer setting. It has an effect that a sufficient three-dimensional sound effect can be obtained under the conditions.

According to a second aspect of the present invention, an output of a first delay means for delaying an output of a first FIR filter for performing a head-related transfer function operation on a signal L or a head-related transfer function for a signal L Either the output of the first FIR filter for performing the operation or the output of the first delay means for delaying the signal L is output to the left speaker, and the second FIR filter for performing the HRTF operation on the signal R The output of the second delay means for delaying the output of the second FIR filter, or the output of the second FIR filter which performs the HRTF operation on the signal R;
Or the output of the second delay means for delaying the signal R,
Is provided to the first virtual signal conversion means for outputting any one of the virtual speakers to the right speaker. The distance between the virtual left speaker and the virtual right speaker can be increased, and a plurality of viewers can This has the effect that the viewing range can be expanded even when viewing.

An embodiment of the present invention will be described below with reference to the drawings. (Embodiment 1) FIG. 1 is a block diagram showing a configuration of an audio signal reproducing apparatus according to Embodiment 1 of the present invention. FIG.
, 1 is an LE input terminal for inputting an audio LE including a surround effect, 2 is an RE input terminal for inputting an audio RE including a surround effect, 4 is a left speaker,
5 is a right speaker, 6 is a virtual center speaker, 7 is a virtual left speaker, 8 is a virtual right speaker, 9 is a virtual left speaker, 10 is a virtual right speaker, 11 is a surround audible range, and 12 is a first viewer. , 13 are second viewers, 14 is third viewers, 20 is position sensor means for detecting position information of a plurality of viewers using, for example, a plurality of television cameras or the like, and 21 is an output of the position sensor means 20 Is converted into information on the viewing center position and the viewing range to set the viewing area based on the information, and is output.At the same time, it is determined whether this information is out of the applicable range, has caused a calculation error, or is within the applicable range. The area calculation means 22 for outputting a control signal is provided with a standard viewing center to cover general (standard use) conditions when the output of the position sensor means 20 is not used. A preset data memory 23 for outputting information on the position and the viewing range. A preset data memory 23 stores the preset data memory 22 when the output of the area computing means 21 is out of the applicable range or a computing error occurs based on the control signal from the area computing means 21. A switching unit 24 for selecting an output and selecting and outputting the output of the area calculation unit 21 when the output is within the applicable range; and a switching unit 24 for controlling the effect of the virtual signal conversion.
Is output as a first output to the area data memory 25, which will be described later, and then outputs the area data memory 25 corresponding to this output.
Effect control means for outputting, as a second output, an optimal parameter for virtual signal conversion in a viewing area used for a first virtual signal conversion means 26, which will be described later, based on the output from the control unit 25; Between the left speaker 4 and the right speaker 5 with respect to a typical pattern of a plurality of viewing areas, the viewing center position which is also the depth position of the virtual left speaker 9 and the virtual right speaker 10, the virtual left speaker 7 and the virtual right speaker 8 Area data memory for selecting and outputting a set of spatial parameters based on the first output of the effect control means 24 from the spatial parameters of the virtual signal conversion such as the interval between the virtual signal and the spatial signal; Input from terminal 1 and RE input terminal 2 and effect control means 2
A first virtual signal conversion means for performing a head-related transfer function operation for obtaining characteristics of a virtual speaker by controlling a filter coefficient for determining a surround effect based on the second output of the fourth speaker 4 and outputting to the left speaker 4 and the right speaker 5 It is.

The operation will be described below. First, the position sensor 20 detects and outputs the positions and ranges of a plurality of viewers. The area calculating means 21 assigns a coefficient and a time constant for preventing the malfunction of the output of the position sensor means 20 and then converts the output into information of the viewing center position and the viewing range and outputs the information. Further, it determines whether this information is out of the predetermined applicable range, or that an arithmetic error has occurred, or is within the applicable range, and outputs a control signal. On the other hand, in the preset data memory 22, the room size, the number of people, the left speaker 4 and the right speaker 5
The information of the viewing center position and the viewing range of the standard area, which is set in advance, is output based on the interval between them and the viewing center position. Switching means 2
In 3, the output of the preset data memory 22 is selected based on the control signal from the area calculating means 21 and the output of the area calculating means 21 is out of the predetermined applicable range or when an arithmetic error occurs, and is selected within the applicable range. In this case, the output of the area calculation means 21 is selected and output. Effect control means 24
In order to control the effect of the virtual signal conversion, the information of the viewing center position and the viewing range, which are the outputs of the switching means 23, are output as a first output to an area data memory 25 to be described later. Based on the output from the area data memory 25, the optimum parameters for virtual signal conversion in the viewing area used by the first virtual signal conversion means 26 described later are output as the second output.
In the area data memory 25, the first
And outputs a set of spatial parameters based on the output of. The first virtual signal conversion means 26 inputs the sound including the surround information from the LE input terminal 1 and the RE input terminal 2 and controls the coefficient of the FIR filter which determines the surround effect based on the second output of the effect control means 24. Thus, a signal that makes the virtual sound output from a plurality of virtual speakers is output to the left speaker 4 and the right speaker 5.

As described above, even if the position of the viewer is shifted, the viewing center position and the viewing range are detected by the position sensor means 20, and the area calculation means 21, the switching means 23, the effect control means 24, the area data memory 25, the first The surround effect can be obtained by following the position of the viewer by the feedback loop of the virtual signal converter 26.

Next, the configuration of the first virtual signal conversion means 26 will be described with reference to FIG. FIG. 2 is a block diagram showing a configuration of the first virtual signal conversion means 26 in the audio signal reproduction device according to the first embodiment. 261 and 262 are ADs for converting analog signals into digital signals.
The converters 263 and 264 convert a digital signal into an analog signal. The DA converter 265 converts the signal including the surround effect input from the AD converters 261 and 262 to L.
Decoders for decoding signals (for left speaker), R (for right speaker), C (for center speaker), and S (for surround speaker), 266, 267, 280, and 282 are positions where sound is present to the viewer. Filters 268, 269, 272, 273, 281 and 28 that implement digital processing of the head related transfer function in the time domain so as to localize
Reference numeral 3 denotes delay means 270, 271, 274 for delaying t1, t1, t2, t3, t4, and t5, respectively, so that the sound source is heard as far as the distance determined by the product of these periods and the sound speed. And 275, an adding means.

The operation will be described below. The signal LE including the surround effect is input from the input terminal 26a and A
The signal is input to the decoder 265 through the D converter 261. The signal RE including the surround effect is input from the input terminal 26b, passes through the AD converter 262, and is input to the decoder 265. These signals are passed through decoder 265 to L, R, C and S
To decode the signal. The signal S branches into two, one of which is FI
The signal passes through an R filter 266 and the other is an FIR filter 267
Pass through. The output of the FIR filter 266 branches into two, one of which is input to the adding means 270 and the other is input to the adding means 271 through the delay means 268. The output of the FIR filter 267 is branched into two, one of which is input to the adding means 271, and the other is input to the adding means 270 through the delay means 269. The output of the adding means 270 passes through the delay means 272 and
Enter 74. The output of the adding means 271 is
And input to the adding means 275. The signal C is split into two, one of which is input to the adding means 274 and the other of which is
Enter 5 The signal L passes through an FIR filter 280 which is also a first FIR filter, and is input to an adding means 274 through a delay means 281 which is also a first delay means. The signal R is output from an FIR filter 28 which is also a second FIR filter.
The signal is input to the adding means 275 through the delay means 283 which is also the second delay means. The output of the adding means 274 is D
The signal is output to the output terminal 26c through the A converter 263.
The output of the adding means 275 is output to the output terminal 26d through the DA converter 264. The signal L is applied to the FIR filter 280
Through the delay means 281, the localization position of the virtual left speaker 7 can be shifted further to the left as compared with the conventional case, and the depth distance can be changed. Similarly, signal R passes through FIR filter 282 and delay means 28
3, the virtual right speaker 8 can be shifted to the right in the localization position and the depth distance can be changed as compared with the conventional case. In general, it is known that if the distance between the left and right speakers is increased, the viewing range is also increased.

As described above, by enlarging the interval between the left and right virtual speakers, the surround audible range 11 can be expanded to expand the viewing range, so that the first viewer 12
In addition, the second viewer 13 and the third viewer 14 can hear the sound having the surround effect.

In the above description, the signal L or the signal R
In the above, the case where the FIR filter and the delay unit are used has been described, but the case where only the FIR filter or only the delay unit is used may be used. This is because the viewing range can be expanded because the virtual left speaker 7 and the virtual right speaker 8 can be enlarged.

These filters need to be driven in a time-division manner so that a plurality of virtual speakers sound simultaneously.

As described above, according to the present embodiment, the position sensor means 20 captures the viewing center positions and viewing ranges of a plurality of viewers, and the output of the area calculation means 21 is out of the applicable range or a calculation error is detected. The viewing area is set depending on whether the situation occurs or within the applicable range. Then, a parameter corresponding to the viewing area is taken out from the area data memory 25 and supplied from the effect control means 24 to the first virtual signal conversion means 26 so that the distance between the virtual left speaker 7 and the virtual right speaker 8 and the virtual left speaker 9 and virtual right speaker 10
Signal that can determine the depth position of the viewer, eliminates the need for confusing viewers to input and adjust spatial position information when multiple viewers view, and obtains a sufficient stereophonic effect while eliminating viewer settings A playback device can be obtained.

Further, the output of the first delay means 281 for delaying the output of the first FIR filter 280 for performing the head-related transfer function operation on the signal L, or the first FIR for performing the head-related transfer function operation on the signal L The output of the filter 280,
Or the output of the first delay means 281 for delaying the signal L is output to the left speaker 4, and the second FIR filter 282 for performing the head related transfer function operation on the signal R
Of the output of the second delay means 283 for delaying the output of the second delay means 283, or the output of the second FIR filter 282 for performing a head-related transfer function operation on the signal R, or the output of the second delay means 283 for delaying the signal R By providing the first virtual signal conversion means 26 for outputting either one to the right speaker 5, the distance between the virtual left speaker 7 and the virtual right speaker 8 can be increased, so that a plurality of viewers can view and listen. Even so, the viewing range can be expanded.

[0025]

As described above, according to the present invention, the position sensor means captures the viewing center positions and viewing ranges of a plurality of viewers and the output of the area calculation means is out of the applicable range or a calculation error occurs. The viewing area is set according to whether the area is within the applicable range. Then, a parameter corresponding to the viewing area is taken out from the area data memory and supplied from the effect control means to the first virtual signal conversion means, so that the distance between the virtual left speaker and the virtual right speaker, the virtual left speaker and the virtual right speaker are obtained. Signal that can determine the depth position of the viewer, eliminates the need for confusing viewers to input and adjust spatial position information when multiple viewers view, and obtains a sufficient stereophonic effect while eliminating viewer settings An excellent effect that a reproducing apparatus can be obtained is obtained.

Also, the output of the first delay means for delaying the output of the first FIR filter for performing the head-related transfer function operation on the signal L, or the output of the first FIR filter for performing the head-related transfer function operation on the signal L A second delay for outputting either the output or the output of the first delay means for delaying the signal L to the left speaker and delaying the output of the second FIR filter for performing the head related transfer function operation on the signal R A first virtual output which outputs to the right speaker either the output of the means or the output of the second FIR filter which performs the head related transfer function operation on the signal R, or the output of the second delay means for delaying the signal R By providing the signal conversion means, the distance between the virtual left speaker and the virtual right speaker can be increased, and as a result, the viewing range can be expanded. Excellent effect that the viewer can view is obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an audio signal reproducing device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a first virtual signal conversion unit of the audio signal reproduction device according to the embodiment of the present invention.

FIG. 3 is a block diagram showing a configuration of a conventional audio signal reproducing apparatus.

FIG. 4 is a block diagram showing a configuration of a second virtual signal converting means of the conventional audio signal reproducing apparatus.

[Explanation of symbols]

 Reference Signs List 4 left speaker 5 right speaker 20 position sensor means 21 area calculation means 22 preset data memory 23 switching means 24 effect control means 25 area data memory 26 first virtual signal conversion means 280 first FIR filter 282 second FIR Filter 281 First delay means 283 Second delay means

Claims (2)

[Claims] 1. A position sensor means for detecting position information of a plurality of viewers, and based on an output of the position sensor means, the information is converted into information of a viewing center position and a viewing range, and the information is out of an applicable range. Or area calculation means for determining whether a calculation error has occurred or within the applicable range and outputting a control signal, and information on a standard viewing center position and a viewing range when the output of the position sensor means is not used. , A switching means for selecting and outputting an output of the preset data memory and an output of the area calculation means based on a control signal from the area calculation means, and an output of the switching means. Information on the viewing center position and the viewing range is output as a first output, and based on an output from an area data memory described later corresponding to the first output, a viewing area is output. (A) an effect control means for outputting an optimal parameter of the virtual signal conversion in (a) as a second output, and an area data memory for selecting and outputting a set of spatial parameters based on the first output of the effect control means;
A signal including surround information is input, and a head transfer function operation for obtaining characteristics of a virtual speaker is performed by controlling a filter coefficient that determines a surround effect based on a second output of the effect control unit. An audio signal reproducing device comprising first virtual signal converting means for outputting the signal. 2. An output of a first delay means for delaying an output of a first FIR filter for performing a head-related transfer function on the signal L, or a first FIR filter for performing a head-related transfer function on the signal L A second delay for outputting either the output or the output of the first delay means for delaying the signal L to the left speaker and delaying the output of the second FIR filter for performing the head related transfer function operation on the signal R A first virtual output which outputs to the right speaker either the output of the means or the output of the second FIR filter which performs the head related transfer function operation on the signal R, or the output of the second delay means for delaying the signal R An audio signal reproducing device including a signal conversion unit.