JP2022092184A - Voice signal processing device and voice signal processing program - Google Patents

Abstract

To provide a voice signal processing device capable of up-mixing without distorting a stereo sound source.SOLUTION: A voice signal processing device 100 is used to up-mix a stereo sound source to a surrounding sound source. The voice signal processing device 100 includes a separation unit 10, for separating the stereo sound source into a direct sound and an indirect sound, a setting unit 20, for generating parameters for adjusting at least one of the direct sound and the indirect sound, a coefficient generating unit 30, for generating coefficients to be multiplied on the direct sound and the indirect sound for each channel of the surrounding sound source on the basis of the parameters, and a calculation unit 40, for multiplying the coefficients on the direct sound and indirect sound to up-mix a stereo sound source to the surrounding sound source.SELECTED DRAWING: Figure 2

Description

The present invention relates to an audio signal processing device and an audio signal processing program that upmix an audio signal while suppressing deterioration of sound quality.

In recent years, with the realization of 4K broadcasting and 8K broadcasting, there is an increasing demand for upmixing stereo (2ch) audio formats to generate 22.2ch surround audio formats corresponding to 5.1ch surround and 3D audio. In live broadcasting, 4K broadcasting or 8K broadcasting may be performed at the same time as 2K broadcasting by generating 5.1ch surround or 22.2ch surround audio formats in real time from stereo audio formats.

As a specific method of upmixing, as described in Patent Document 1, stereo sound sources are separated into direct sound and indirect sound on the left and right sides, and various types such as delay processing are performed on these four sound sources. By performing the processing, the output of each channel in surround is obtained. Further, in the technique described in Patent Document 2, there is also known a method of separating a stereo sound source into a direct sound and an indirect sound on each of the left and right sides, and then upmixing them using an HRIR. As a method for separating a stereo sound source into a direct sound and an indirect sound, a method of extracting a coherent component from the stereo sound source is excellent as described in Patent Document 3.

Japanese Unexamined Patent Publication No. 2015-06857 JP-A-2017-163458 International Publication No. 2017/188141

However, in Patent Documents 1 and 2, since the stereo sound source is separated and then the delay processing and the filter processing associated with the HRIR are performed, there is a problem that the original sound source is distorted. In particular, in recent years, there has been a demand to downmix a surround sound source generated by upmixing from a stereo sound source to a stereo sound source again, but if the original sound source is distorted during upmixing, it is stereo. There was also the problem that such distortion remained even when downmixing to the sound source of. Further, in Patent Document 2, although a reference HRIR is required, there is also a problem that it is difficult to obtain it.

An object of the present invention is to provide an audio signal processing device capable of upmixing a stereo sound source so as not to cause distortion in order to solve the above problems.

The audio signal processing device of the present invention has the following configuration.
(1) An audio signal processing device that upmixes a stereo sound source to a surround sound source.
(2) A separation unit that separates the stereo sound source into direct sound and indirect sound.
(3) A setting unit that generates parameters for adjusting at least one of the direct sound and the indirect sound.
(4) A coefficient generation unit that generates a coefficient for multiplying the direct sound and the indirect sound for each channel in the surround sound source based on the parameter.
(5) A calculation unit that upmixes the stereo sound source to the surround sound source by multiplying the direct sound and the indirect sound by the coefficient.

Further, the audio signal processing device of the present invention may further include the following configurations.
(1) The parameter includes a parameter for adjusting the balance between a center sound source and a sound source other than the center sound source in the front channel of the surround sound source.
(2) The parameter includes a parameter for adjusting the balance between the center sound source and a sound source other than the center sound source in the rear channel of the surround sound source.
(3) The parameter includes a parameter for adjusting the mixing amount of the indirect sound with respect to the direct sound output from the front side channel of the surround sound source.
(4) The surround sound source corresponds to 3D audio, and the parameters are the direct sound and the indirect sound output from the middle layer channel in the surround sound source, and the direct sound output from the upper and lower layer channels. Includes those that adjust the balance between sound and the indirect sound.
(5) The parameter includes a parameter for adjusting the balance between the direct sound and the indirect sound.
(6) The setting unit includes a direct sound / indirect sound balance adjusting unit, and the direct sound / indirect sound balance adjusting unit adjusts the balance between the direct sound and the indirect sound.

The audio signal processing program of the present invention has the following configuration.
(1) An audio signal processing program that causes a computer to execute a process of upmixing a stereo sound source to a surround sound source.
(2) Separation procedure for separating the stereo sound source into direct sound and indirect sound.
(3) A setting procedure for generating a parameter for adjusting at least one of the direct sound or the indirect sound.
(4) A coefficient generation procedure for generating a coefficient for multiplying the direct sound and the indirect sound for each channel in the surround sound source based on the parameter.
(5) A calculation procedure for upmixing the stereo sound source to the surround sound source by multiplying the direct sound and the indirect sound by the coefficient.

According to the present invention, it is possible to upmix a stereo sound source so as not to cause distortion.

The block diagram which shows the structure of the audio signal processing apparatus of embodiment. The block diagram which shows a part of the structure of the audio signal processing apparatus of embodiment in detail. The figure which shows the operation in the direct sound / indirect sound balance adjustment part of embodiment. The figure which shows the operation in the front balance adjustment part of an embodiment. The figure which shows the operation in the rear balance adjustment part of an embodiment. The figure which shows the operation in the mixing amount adjustment part of an embodiment. The figure which shows the operation in the interlayer balance adjustment part of an embodiment. The figure which shows the operation in the arithmetic part of embodiment. The flowchart which shows the operation of the audio signal processing apparatus of embodiment. The block diagram which shows a part of the structure of the audio signal processing apparatus of another embodiment in detail.

[First Embodiment]
[Constitution]
The audio signal processing device 100 of the present embodiment shown in FIG. 1 is known as, for example, an audio adjusting console or a mixer. In the following description, an upmix from stereo to 22.2ch surround will be taken as an example, and the audio signal input to the audio signal processing device 100 will be that of a stereo sound source. 22.2ch surround is composed of 24 channels of channels 1 to 24. Specifically, it is composed of 9 channels in the upper layer, 10 channels in the middle layer, and 3.2 channels in the lower layer. The lower 3.2 channel contains two LFEs. Further, 22.2ch surround can be considered by dividing it into 11.2 channels on the front side and 11 channels on the side and rear sides. For the sake of simplicity, it is assumed that the direct sound is mainly output from the front side channel and the indirect sound is mainly output from the side side channel and the rear side channel, but the indirect sound is mainly output from the front side channel. It may be output.

The audio signal processing device 100 has a separation unit 10 that separates a stereo sound source into direct sound and an indirect sound on each of the left and right sides, a setting unit 20 that generates various parameters for adjusting the separated sound sources, and generated parameters. It includes a coefficient generation unit 30 that generates a coefficient based on the coefficient, and a calculation unit 40 that generates a surround sound source that is upmixed from the coefficient and a sound source separated from the coefficient.

The separation unit 10 separates the stereo sound source into direct sound and indirect sound on the left and right sides, respectively. That is, it is separated into four sound sources: left direct sound DL, right direct sound DR, left indirect sound RL, and right indirect sound RR. As a method for separating a stereo sound source into a direct sound and an indirect sound, a well-known technique such as the technique of Patent Document 3 described in the background technique can be used. The separation unit 10 outputs these four sound sources to the calculation unit 40 provided in the subsequent stage. The direct sound is a sound that reaches the ear directly, and the indirect sound is a sound that is reflected by a wall or the like and reaches the ear.

The setting unit 20 generates parameters for adjusting the four sound sources separated by the separation unit 10. As shown in FIG. 2, the setting unit 20 adjusts the balance between the direct sound / indirect sound balance adjusting unit 21 that adjusts the balance between the direct sound and the indirect sound, and the center sound source and the sound source other than the center sound source in the direct sound. The front balance adjusting unit 22 for adjusting the balance between the center sound source and the sound source other than the center sound source in the indirect sound, and the mixing amount adjusting unit 24 for adjusting the mixing amount between the direct sound and the indirect sound. The layer balance adjusting unit 25 for adjusting the balance between the output from the middle layer channel and the output from the upper and lower layer channels in the direct sound and the indirect sound is provided.

As shown in FIG. 3, the direct sound / indirect sound balance adjusting unit 21 includes, for example, one operator, and when the operator is rotated to the left, the mixing amount of the direct sound increases, and when the operator is rotated to the right, the mixing amount is indirect. The amount of sound mixing increases. The mixing engineer adjusts the balance between the direct sound and the indirect sound in the surround sound source after the upmix by rotating this controller left and right. The degree of this adjustment is output as a ROOM value to the calculation unit 40 provided in the subsequent stage.

As shown in FIG. 4, the front balance adjusting unit 22 adjusts the balance between the center sound source and the sound source other than the center sound source among the direct sounds. This center sound source is a component of the direct sound that is localized in the center. Further, the sound source other than the center sound source is a component of the direct sound other than the center sound source. The front balance adjusting unit 22 includes, for example, one operator, and when the operator is rotated to the left, the mixing amount of the center sound source increases, and when the operator is rotated to the right, the mixing amount of the sound sources other than the center sound source increases. By rotating this controller left and right, the mixing engineer adjusts the balance between the center sound source output from the front channel and the sound sources other than the center sound source in the surround sound source after upmixing. The degree of this adjustment is output as an Fdiv value to the coefficient generation unit 30 provided in the subsequent stage.

As shown in FIG. 5, the rear balance adjusting unit 23 adjusts the balance between the center sound source and the sound source other than the center sound source among the indirect sounds. This center sound source is a component of the indirect sound that is localized in the center. Further, the sound source other than the center sound source is a component of the indirect sound other than the center sound source. The rear balance adjusting unit 23 includes, for example, one operator, and when the operator is rotated to the left, the mixing amount of the center sound source increases, and when the operator is rotated to the right, the mixing amount of the sound sources other than the center sound source increases. By rotating this controller left and right, the mixing engineer adjusts the balance between the center sound source output from the rear channel and the sound sources other than the center sound source in the surround sound source after upmixing. The degree of this adjustment is output as an Rdiv value to the coefficient generation unit 30 provided in the subsequent stage.

As shown in FIG. 6, the mixing amount adjusting unit 24 adjusts the mixing ratio of the indirect sound to the direct sound output from the front side channel and the mixing ratio of the direct sound to the indirect sound output from the rear side channel. For this purpose, the mixing amount adjusting unit 24 includes, for example, a main operator X and a sub-operator Y.

The main operator X adjusts the balance between the direct sound output from the front channel and the indirect sound. For example, rotating the main controller X to the left reduces the mixing amount of direct and indirect sounds, and rotating it to the right increases the mixing amount of direct and indirect sounds. On the other hand, the sub-operator Y adjusts the amount of mixing the direct sound with respect to the indirect sound and the amount of mixing the indirect sound with respect to the direct sound output from the front side channel. For example, rotating the sub-operator Y to the left reduces the amount of direct sound that mixes with the indirect sound and the amount of indirect sound that mixes with the direct sound, and rotating it to the right reduces the amount of indirect sound that mixes with the indirect sound. The amount of direct sound to be made and the amount of indirect sound to be mixed with the direct sound are increased. The mixing engineer adjusts the mixing ratio of the indirect sound to the direct sound output from the front channel and the mixing ratio of the direct sound to the indirect sound by rotating the main operator X and the sub-operator Y. The main operator X and the sub-operator Y may be interlocked with each other, or the main operator X may be fixed and only the sub-operator Y may rotate. In the case of interlocking, it is preferable to rotate the sub-operator Y in the direction opposite to the rotation direction of the main operator X. The degree of this adjustment is output as a FRdiv value to the coefficient generation unit 30 provided in the subsequent stage.

As shown in FIG. 7, when the surround sound source after upmix corresponds to 3D audio, the interlayer balance adjusting unit 25 outputs the direct sound and the indirect sound output from the middle layer channel and the upper and lower layer channels. Adjust the balance between the direct sound and the indirect sound. That is, the interlayer balance adjusting unit 25 includes, for example, one operator, and when this operator is rotated to the left, the direct sound and the indirect sound output from the middle layer channel are emphasized, and when the operator is rotated to the right, the upper and lower layer channels are emphasized. The output direct and indirect sounds are emphasized. The mixing engineer adjusts the balance between the direct sound and the indirect sound output from the middle layer channel and the direct sound and the indirect sound output from the upper and lower layer channels by rotating this operator left and right. The degree of this adjustment is output as an ELdiv value to the coefficient generation unit 30 provided in the subsequent stage.

Returning to FIG. 2, the coefficient generation unit 30 generates the coefficients A, B, C, and D by performing four arithmetic operations by arbitrarily combining the four parameters Fdiv, Rdiv, FRdiv, and ELdiv generated by the setting unit 20. In addition, this combination and four arithmetic operations are different for each channel in surround. That is, by combining the values of Fdiv, Rdiv, FRdiv, and ELdiv for each of 22.2 channels, 24 sets of coefficients A1 to D1, ..., A24 to D24 are generated.

The generation of each coefficient An to Dn will be described in more detail. Fdiv consists of AnFdiv, BnFdiv, CnFdiv, and DnFdiv. Similarly, Rdiv consists of AnRdiv, BnRdiv, CnRdiv, DnRdiv, FRdiv consists of AnFRdiv, BnFRdiv, CnFRdiv, DnFRdiv, and ELdiv consists of AnELdiv, BnELdiv, CnELdiv.

For example, by rotating the operator of the front balance adjusting unit 22, AnFdiv and BnFdiv are generated for each channel in the surround sound source. Similarly, by rotating the operator of the rear balance adjusting unit 23, CnRdiv and DnRdiv are generated for each channel in the surround sound source, and by rotating the operator of the mixing amount adjusting unit 24, the channel in the surround sound source is generated. AnFRdiv, BnFRdiv, CnFRdiv, and DnFRdiv are generated for each, and by rotating the operator of the interlayer balance adjusting unit 25, AnELdiv, BnELdiv, CnELdiv, and DnELdiv are generated for each channel in the surround sound source.

And An to Dn are generated by each of the following equations.
An = AnFdiv x AnRdiv x AnFRdiv x AnELdiv
Bn = BnFdiv × BnRdiv × BnFRdiv × BnELdiv
Cn = CnFdiv × CnRdiv × CnFRdiv × CnELdiv
Dn = DnFdiv × DnRdiv × DnFRdiv × DnELdiv

The coefficients A1 to D1, ..., A24 to D24 generated as described above are output to the calculation unit 40 provided in the subsequent stage.

As shown in FIG. 8, the calculation unit 40 includes four sound source DLs, DRs, RLs, and RRs separated by the separation unit 10, a parameter ROOM generated by the direct sound / indirect sound balance adjustment unit 21, and a coefficient generation unit 30. The audio signals output from each channel in the surround after upmix are calculated based on the coefficients A1 to D1, ..., A24 to D24 generated by. The calculation unit 40 calculates the output T from each channel by the following (Equation 1). In (Equation 1), the output T and n attached to each of the coefficients A, B, C, and D are the channel numbers in surround, and for example, T1 is the output T of the channel 1. Further, DL', DR', RL', and RR'are DL, DR, RL, and RR adjusted by ROOM values, respectively. As a result, the arithmetic unit 40 generates outputs T1 to T24 from channels 1 to 24, respectively, and generates a surround sound source. The upmixed surround sound source is output to the outside from an output device such as a speaker (not shown) provided for each channel.
(Number 1)
Tn = An x DL'+ Bn x DR'+ Cn x RL'+ Dn x RR'... (Equation 1)

[Action]
The operation of the audio signal processing device 100 in the present embodiment will be described with reference to FIG. 9. First, a stereo sound source, which is the original audio signal, is input to the separation unit 10. The separation unit 10 separates the stereo sound source into four sound sources: a left direct sound DL, a right direct sound DR, a left indirect sound RL, and a right indirect sound RR (step S01). The four separated sound sources are input to the calculation unit 40.

In the setting unit 20, the direct sound / indirect sound balance adjusting unit 21 sets the ROOM value, the front balance adjusting unit 22 sets the Fdiv value, the rear balance adjusting section 23 sets the Rdiv value, and the mixing amount adjusting section 24 sets the FRdiv value between layers. The balance adjustment unit 25 generates ELdiv values, respectively, and outputs them to the coefficient generation unit 30 or the calculation unit 40 provided in the subsequent stage (step S02). More specifically, in each of these configurations, the mixing engineer rotates one or two controls to adjust the mixing amount to adjust at least one of the direct and indirect sounds. As a result of this adjustment, each of the above parameters is generated. The ROOM value and the coefficients generated based on the four parameters Fdiv, Rdiv, FRdiv, and ELdiv are input to the calculation unit 40 and reflected in the surround sound source after the upmix. That is, it can be said that the adjustment of the mixing amount in the setting unit 20 adjusts the surround sound source after the upmix.

The coefficient generation unit 30 generates coefficients A, B, C, and D for each channel in the surround output by performing four arithmetic operations by arbitrarily combining the four parameters Fdiv, Rdiv, FRdiv, and ELdiv generated by the setting unit 20. do. That is, by combining the values of Fdiv, Rdiv, FRdiv, and ELdiv for each of 22.2 channels, 24 sets of coefficients A1 to D1, ..., A24 to D24 are generated (step S03). The coefficients A1 to D1, ..., A24 to D24 are output to the calculation unit 40 provided in the subsequent stage. In the generation of the coefficients Cn and Dn of the indirect sounds RL and RR, it is not necessary to use the Fdiv value related to the mixing amount of the direct sound. Similarly, in the generation of the coefficients An and Bn of the direct sound DL and DR, it is not necessary to use the Rdiv value related to the mixing amount of the indirect sound. As described above, it is not always necessary to use all the parameters in the generation of each coefficient. Further, depending on the channel, it is not necessary to generate all the coefficients by four arithmetic operations. For example, the coefficient of the left channel output on the front side of the middle layer can be Bn = Dn = 1.

The calculation unit 40 includes four sound source DLs, DRs, RLs, and RRs generated by the separation unit 10, a parameter ROOM generated by the direct sound / indirect sound balance adjustment unit 21, and 24 sets of coefficients generated by the coefficient generation unit 30. Based on A1 to D1, ..., A24 to D24, the outputs T1 to T24 of each channel in 22.2ch surround are calculated from the above (Equation 1) (step S04). The calculated outputs T1 to T24 are output from speakers (not shown) provided for each channel in surround.

[effect]
(1) In the audio signal processing device 100 of the present embodiment, the left direct sound DL, the right direct sound DR, the left indirect sound RL, and the right indirect sound RR generated by separating the stereo sound source by the separation unit 10 After adjusting the four sound sources of the above by the ROOM value generated by the direct sound / indirect sound balance adjusting unit 21, the coefficient generation unit is based on the four parameters Fdiv, Rdiv, FRdiv, and ELdiv generated by the setting unit 20. The calculation unit 40 multiplies the coefficient generated by 30 to generate a surround sound source from the stereo sound source. In this way, since the stereo sound source is upmixed without performing delay processing or filter processing, distortion of the sound source due to the upmix can be suppressed. Therefore, even if the upmixed surround sound source is downmixed to the stereo sound source again, the distortion that occurs in the stereo sound source is small.

(2) The setting unit 20 of the audio signal processing device 100 of the present embodiment includes a front balance adjusting unit 22. As a result, only the center sound source can be emphasized in the front channel output as compared with other sound sources, so that it is possible to avoid a situation in which the center sound source is buried in other sound sources and becomes difficult to hear. In particular, when the center sound source contains important information such as comments, it is possible to avoid the situation where the comments cannot be heard.

(3) The setting unit 20 of the audio signal processing device 100 of the present embodiment includes a rear balance adjusting unit 23. As a result, the balance between the center sound source and other sound sources can be adjusted in the rear side channel output, so that it is possible to adjust how the sound output from the rear side channel spreads.

(4) The setting unit 20 of the audio signal processing device 100 of the present embodiment includes a mixing amount adjusting unit 24. As a result, even if the center sound source is weaker than other sound sources, the center sound source output from the front side channel can be obtained by mixing the indirect sound with the direct sound output from the front side channel. It can be reinforced to make it easier to hear the sound localized in the center. Similarly, the center sound source can be reinforced by mixing the direct sound with the indirect sound.

(5) The setting unit 20 of the audio signal processing device 100 of the present embodiment includes an interlayer balance adjusting unit 25. As a result, the direct sound and the indirect sound in the middle layer in surround can be extended to the upper layer and the lower layer.

(6) The setting unit 20 of the audio signal processing device 100 of the present embodiment includes a direct sound / indirect sound balance adjusting unit 21. This makes it possible to emphasize the indirect sound in the surround sound source after the upmix.

[Other embodiments]
The present invention is not limited to the above embodiment, and at the implementation stage, the components can be modified and embodied within a range that does not deviate from the gist thereof. In addition, various inventions can be formed by an appropriate combination of the plurality of components disclosed in the above-described embodiment. For example, some components may be removed from all the components shown in the embodiments. Specifically, it also includes other embodiments such as the following.

(1) In the above embodiment, the upmix from stereo to 22.2ch surround has been described, but for example, the upmix from stereo to 5.1ch surround and 5.12ch corresponding to stereo to 3D audio are supported. The present invention can also be applied to upmix to surround.

(2) In the above embodiment, the output Tn of each channel is calculated, but the present invention is not limited to this. For example, the outputs of the left and right channels on the front side and the left and right channels on the side and rear sides may be the same. As a result, the amount of calculation of the coefficient generation unit 30 and the calculation unit 40 can be reduced.

(3) The setting unit 20 of the above embodiment is designed to generate four parameters Fdiv, Rdiv, FRdiv, and ELdiv, but the present invention is not limited to this. If even one setting unit 20 can generate a parameter, it is possible to finely adjust the output Tn of each channel n by diversifying the four arithmetic operations for generating the coefficients An to Dn. Further, as shown in FIG. 10, the coefficients An to Dn may be generated with five parameters including the Room value. In this case, for example, the coefficient can be generated by the following equations. However, it is assumed that AnRoom = BnRoom and CnRoom = DnRoom = 1-AnRoom.
An = AnRoom × AnFdiv × AnRdiv × AnFRdiv × AnELdiv
Bn = BnRoom × BnFdiv × BnRdiv × BnFRdiv × BnELdiv
Cn = CnRoom × CnFdiv × CnRdiv × CnFRdiv × CnELdiv
Dn = DnRoom × DnFdiv × DnRdiv × DnFRdiv × DnELdiv

(4) In the setting unit 20 of the above embodiment, the mixing engineer generates the parameters by operating the controls provided in each configuration, but operates the GUI provided in the audio signal processing device 100. May generate parameters by.

(5) The setting unit 20 of the above embodiment includes a direct sound / indirect sound balance adjusting unit 21, a front balance adjusting unit 22, a rear balance adjusting unit 23, a mixing amount adjusting unit 24, and an interlayer balance adjusting unit 25. However, in addition to these configurations, an equalizer may be provided. In this case, the equalizer is used to the extent that the stereo sound source is not distorted too much.

(6) The mixing amount adjusting unit 24 of the above embodiment adjusts the amount of indirect sound mixed with respect to the direct sound and the amount of direct sound mixed with respect to the indirect sound, but only in the former case. There may be. That is, it is not necessary to mix the direct sound with the indirect sound.

(7) The interlayer balance adjusting unit 25 of the above embodiment is to expand the direct sound and the indirect sound of the middle layer in the surround sound source to the upper and lower layers with one operator, but by providing two controls, the layer balance adjusting unit 25 is provided. It is also possible to adjust the direct sound and the indirect sound individually. The two controls may be interlocked with each other, or one may be fixed and only the other may rotate. In the case of interlocking, it is preferable to rotate the other in the direction opposite to the rotation direction of one.

(8) In the above embodiment, the hardware of the audio signal processing device 100 has been described, but the same effect can be obtained by software such as a program that causes a computer to execute the operation of each configuration of the audio signal processing device 100 as a procedure. I can play it. For example, a separation procedure for separating a stereo sound source into direct sound and indirect sound instead of the voice signal processing device 100 including a separation unit 10, a setting unit 20, a coefficient generation unit 30, and a calculation unit 40 as a configuration. , A setting procedure that generates a parameter for adjusting at least one of the direct sound or the indirect sound, and a coefficient generation procedure that generates a coefficient for multiplying the direct sound and the indirect sound for each channel in the surround sound source based on the parameter. A similar effect can be achieved by a voice signal processing program that causes a computer to perform an arithmetic procedure for upmixing a stereo sound source to a surround sound source by multiplying the direct sound and the indirect sound by a coefficient. This procedure is performed, for example, in the same manner as described in FIG.

100 ... Audio signal processing device 10 ... Separation unit 20 ... Setting unit 21 ... Direct sound / indirect sound balance adjustment unit 22 ... Front balance adjustment unit 23 ... Rear balance adjustment unit 24 ... Mixing amount adjustment unit 25 ... Interlayer balance adjustment unit 30 ... Coefficient generation unit 40 ... Calculation unit X ... Main operator Y ... Sub-operator DL ... Left direct sound DR ... Right direct sound RL ... Left indirect sound RR ... Right indirect sound A to D ... Coefficient T ... Output

Claims (8)

An audio signal processing device that upmixes a stereo sound source to a surround sound source.
A separation unit that separates the stereo sound source into direct sound and indirect sound,
A setting unit that generates parameters for adjusting at least one of the direct sound and the indirect sound, and
A coefficient generator that generates a coefficient for multiplying the direct sound and the indirect sound for each channel in the surround sound source based on the parameters.
An audio signal processing device including a calculation unit that upmixes the stereo sound source to the surround sound source by multiplying the direct sound and the indirect sound by the coefficient. The parameters include those for adjusting the balance between the center sound source and the sound sources other than the center sound source in the front channel of the surround sound source.
The audio signal processing device according to claim 1. The parameters include those for adjusting the balance between the center sound source and the sound sources other than the center sound source in the rear channel of the surround sound source.
The audio signal processing device according to claim 1 or 2. The parameters include those for adjusting the mixing amount of the indirect sound with respect to the direct sound output from the front side channel of the surround sound source.
The audio signal processing device according to any one of claims 1 to 3. The surround sound source supports 3D audio and is compatible with 3D audio.
The parameters include adjusting the balance between the direct sound and the indirect sound output from the middle layer channel in the surround sound source and the direct sound and the indirect sound output from the upper and lower layer channels.
The audio signal processing device according to any one of claims 1 to 4. The parameters include those for adjusting the balance between the direct sound and the indirect sound.
The audio signal processing device according to any one of claims 1 to 5. The setting unit includes a direct sound / indirect sound balance adjustment unit.
The direct sound / indirect sound balance adjusting unit adjusts the balance between the direct sound and the indirect sound.
The audio signal processing device according to any one of claims 1 to 5. An audio signal processing program that causes a computer to perform a process of upmixing a stereo sound source to a surround sound source.
The separation procedure for separating the stereo sound source into direct sound and indirect sound,
A setting procedure for generating parameters for adjusting at least one of the direct sound or the indirect sound, and
Based on the parameters, a coefficient generation procedure for generating a coefficient for multiplying the direct sound and the indirect sound for each channel in the surround sound source, and a coefficient generation procedure.
A voice signal processing program that causes a computer to perform an arithmetic procedure for upmixing a stereo sound source to a surround sound source by multiplying the direct sound and the indirect sound by the coefficient.

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