JPH11184471A - Waveform generating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To generate a musical sound waveform which increase the effect of morphing. SOLUTION: A Fourier transform part 2 processes two kind of digital signals read out of a waveform memory 1 by Fourier transformation to separate amplitude spectra and phase spectra by the digital signals. An amplitude cross-fade part 3 puts the separated amplitude spectra together with a cross-fade curve for amplitude components. A phase cross-fade part 4 puts the separated phase spectra together with a cross-fade curve for phase components. An inverse Fourier transformation part 5 integrates the composite amplitude spectrum and phase spectrum to generate one digital signal. In this case, the amplitude components and phase components are put together in mutually different form.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waveform generator for generating a signal waveform used as a sound source.

[0002]

2. Description of the Related Art A morphing technique for smoothly changing a PCM sound used for a sound source with time has been conventionally performed. For example, in the case of a crossfade in which one musical tone fades out while another musical tone fades in, the amplitude component of the musical tone that fades out is smoothly reduced, and the amplitude component of the musical tone that fades in is smoothly increased. In this case, there is also a proposal that after performing a Fourier transform on the PCM sound, an amplitude component in a spectral component of a specific frequency is cross-fade.

[0003]

However, when only the amplitude component is cross-fade, there is a problem that the effect of the morphing is small and the musical interest is lacking. This is the same when Fourier transform is performed. It is an object of the present invention to generate a musical sound waveform that enhances the effect of morphing.

[0004]

SUMMARY OF THE INVENTION The present invention provides a Fourier transform means for performing a Fourier transform on a plurality of types of digital signals to be used as sound sources, and an amplitude spectrum and a phase spectrum of each of the plurality of types of Fourier-transformed digital signals. A spectrum separating means for separating a plurality of types of digital signals, an amplitude spectrum synthesizing means for synthesizing separated amplitude spectra of a plurality of types of digital signals in a set mode, and A phase spectrum synthesizing unit for synthesizing in a mode different from the mode of the means, and a spectrum integrating unit for generating one digital signal by integrating the synthesized amplitude spectrum and the synthesized phase spectrum. I have. According to the present invention, a plurality of types of digital signals are Fourier-transformed, an amplitude spectrum and a phase spectrum are separated for each digital signal, and the separated amplitude spectra are combined with each other in a manner for an amplitude component. The spectra are combined in the phase component mode, and the combined amplitude spectrum and phase spectrum are integrated to generate one digital signal.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, first to sixth embodiments of the waveform generator according to the present invention will be described. FIG. 1 is a part of a block diagram showing a configuration of the first embodiment. FIG.
In the waveform generator of the above, a CPU as a control means for controlling the entire apparatus, and an R which stores a program of the CPU.
Although there is an operation unit including a OM, a RAM for temporarily storing data processed by the CPU, a keyboard, and the like, they are omitted for the sake of simplicity. In the block diagrams of the configurations of other embodiments, the CPU, the ROM, the RAM, and the operation unit are not shown.

In FIG. 1, a waveform memory 1 as waveform storage means stores at least two types of sampled P
One cycle of waveform data having the same pitch and different timbre of CM sounds is stored, and two types of waveform data A and B are output in accordance with a waveform read command from the CPU and a designated address. . The Fourier transform unit 2 Fourier transforms the waveform data A and the waveform data B output from the waveform memory 1, respectively, and separates these spectral components into an amplitude component (amplitude spectrum) and a phase component (phase spectrum), respectively. Output. That is, the Fourier transform unit 2 and the CPU constitute a Fourier transform unit and a spectrum separating unit.

The amplitude component A and the amplitude component B of the waveform data A
Is input to the amplitude crossfade unit 3 and the waveform data B
Are input to the phase crossfade unit 4. That is, the amplitude crossfade unit 3 and the CPU constitute an amplitude spectrum synthesizing unit, and the phase crossfade unit 4 and the CPU constitute a phase spectrum synthesizing unit.

Generally, for integers n and N, 1 ≦ n ≦ N
When the Fourier transform is performed on the waveform data x (n) of the PCM sound,

(Equation 1) It is represented by the following equation. Here, k is an integer of 1 ≦ k ≦ N. Θ = ωt = 2πft. The phase component of this equation is

(Equation 2) Therefore, the real component R (k) and the imaginary component I (k) of the signal are

(Equation 3) It is represented by Therefore, the Fourier-transformed amplitude component | X (k) | and phase component P (k) are

(Equation 4) It is represented by the following equation.

That is, in FIG. 1, the amplitude component A and the amplitude component B input to the amplitude crossfade unit 3 are

(Equation 5) It is represented by the following equation. The phase component A and the phase component B input to the phase crossfade unit 4 are

(Equation 6) It is represented by the following equation. Therefore, the amplitude crossfade section 3
The phase crossfade unit 4 performs a crossfade process of the amplitude component and the phase component according to an instruction from the CPU.

In FIG. 1, the cross-faded amplitude component is output from an amplitude cross-fade unit 3 and input to an inverse Fourier transform unit 5. Further, the cross-fade phase component is output from the phase cross-fade unit 4, and
It is input to the inverse Fourier transform unit 5. Inverse Fourier transform unit 5
Integrates the amplitude component and the phase component, performs an inverse Fourier transform, and stores the result in the waveform memory 1. That is, the inverse Fourier transform unit 5 and the CPU constitute spectrum integrating means.

[0011] A series of operations of the cross-fade processing is as follows.
This will be described with reference to the flowcharts of the CPU shown in FIGS. FIG. 2 shows the flow of the main routine,
It is a flow common to the sixth embodiment. In this main routine, after a predetermined initialization process (step A1), a loop for repeating a waveform synthesis process (step A2) and other processes (step A3) is executed.

FIG. 3 is a flowchart of the waveform synthesizing process in step A2 of FIG. In this process, a waveform designation selection is performed according to an instruction from the operation unit or program data (step B1), and a cross fade curve selection process is performed (step B2). A plurality of types of crossfade curves are stored in the ROM, and a crossfade curve for an amplitude component and a phase component is selected in accordance with an instruction from an operation unit or data of a program, and the amplitude crossfade unit is selected. 3 and the phase crossfade unit 4.

FIG. 5 shows an example of a selected crossfade curve. This is a crossfade curve for crossfading a section from the waveform start end to the waveform end. As for the amplitude component, the section of T1 outputs only the amplitude component A, and the section of T2 and T3 gradually decreases the amplitude component A,
The amplitude component B gradually increases. In the section between T4 and T5, only the amplitude component B is output. On the other hand, as for the phase component, only the phase component A is output in the section between T1 and T2, and in the section between T3 and T4, the phase component A gradually decreases and the phase component B gradually increases. And T5
Outputs only the phase component B. That is, the amplitude component and the phase component are different from each other (timing)
Cross-fade processing is performed.

FIGS. 6 (1) to 6 (6) show examples of various types of amplitude component crossfade curves and phase component crossfade curves. As is clear from these figures, the amplitude component crossfade curve and the phase component crossfade curve are different and independent curves. In FIGS. 6 (1), (2), (4), and (5), the amplitude component and the phase component are cross-fade in the same section and at the same timing, but the cross-fade ratios are different. In FIG. 6C, the amplitude component and the phase component are cross-fade at the same ratio, but the cross-fade sections are different. In FIG. 6 (6), the cross-fade timing is different between the amplitude component and the phase component.

In FIG. 3, after the cross-fade curve selection processing in step B2, a waveform cross-fade processing is performed (step B3), and a storage processing is performed (step B4). In the waveform crossfade processing of step B3,
As shown in FIG. 4, the waveform data output from the waveform memory 1 is Fourier-transformed (step C1). Next, the result of the Fourier transform is separated into an amplitude component and a phase component (step C2). Then, the amplitude components are combined with each other according to the amplitude component cross-fade curve (step C3).
Further, the phase components are combined with each other in accordance with the phase component crossfade curve (step C4).

Next, the combined amplitude component and phase component are integrated and subjected to inverse Fourier transform (step C5). And
The inverse Fourier-transformed waveform data is temporarily stored in a predetermined area of the waveform memory 1 (step C6). next,
It is determined whether or not processing of all the waveforms stored in the waveform memory 1 has been completed (step C7). If the processing of all the waveforms has not been completed, the process proceeds to step C1, and
Perform each of the above processes. When all the waveforms have been processed in step C7, the waveform crossfade processing is ended.

As described above, according to the first embodiment,
The Fourier transform unit 2 calculates the 2
Fourier transform is performed on each type of digital signal, and an amplitude spectrum and a phase spectrum are separated for each digital signal.
The amplitude crossfade unit 3 combines the separated amplitude spectra with each other using a crossfade curve for an amplitude component. The phase crossfade unit 4 combines the separated phase spectra with each other using a phase component crossfade curve. The inverse Fourier transform unit 5 integrates the combined amplitude spectrum and phase spectrum and performs an inverse Fourier transform to generate one digital signal. Therefore, by performing the phase crossfade in a mode (timing, section, ratio) different from the amplitude crossfade process, it is possible to perform a variety of crossfade processes. Can occur.

In the first embodiment, two digital signals are cross-fade, but three or more digital signals may be cross-fade. Also in this case, in a mode (timing, section, ratio) different from the amplitude crossfade processing,
By performing the phase crossfade, crossfade processing with more variety can be performed.

Next, a second embodiment of the present invention will be described. FIG. 7 is a block diagram showing the configuration of the waveform generator according to the second embodiment. In this figure, components having the same configuration as that of the first embodiment shown in FIG. 1 are denoted by the same reference numerals, and description thereof is omitted. In FIG. 7, an amplitude mixing section 6 and a phase mixing section 7 are provided instead of the amplitude crossfade section 3 and the phase crossfade section 4 of FIG.

In FIG. 7, the amplitude component A and the amplitude component B that have been subjected to Fourier transform by the Fourier transform unit 2 and further separated are input to the amplitude mix unit 6. In addition, a touch signal (a signal indicating the strength of the performance operation) as performance data is input to the amplitude mixing unit 6. In the amplitude mixing section 6,
The two amplitude components are mixed at a ratio according to the touch signal and input to the inverse Fourier transform unit 5. The phase component A and the phase component B that have been Fourier transformed by the Fourier transform unit 2 and further separated are input to the phase mixing unit 7. In the phase mixing unit 7, the two phase components are mixed at a ratio according to the touch signal and input to the inverse Fourier transform unit 5. The inverse Fourier transform unit 5 integrates the amplitude component and the phase component and performs an inverse Fourier transform to generate one digital signal and store the digital signal in the waveform memory 1. That is, the amplitude mixing unit 6 and the CPU (not shown) constitute an amplitude spectrum synthesizing unit, and the phase mixing unit 7 and the CPU
Constitutes a phase spectrum synthesizing means.

A series of operations of the mixing process will be further described with reference to the flowcharts of the CPU shown in FIGS. FIG. 8 is a flowchart of the waveform synthesis processing in step A2 of the main flow shown in FIG. In this process, waveform designation selection is performed according to an instruction from the operation unit or program data (step D1), and a mix table selection process is performed (step D2). A plurality of types of mix tables are stored in the ROM,
A mix table for the amplitude component and a phase component is selected according to an instruction from the operation unit or data of the program, and input to the amplitude mix unit 6 and the phase mix unit 7. Therefore, the mixing ratio of the waveform data A and the waveform data B is determined according to the strength of the touch.

FIG. 10 shows an example of the mix table. FIG. 10A shows a mix table for waveform data A, and FIG. 10B shows a mix table for waveform data B. As shown in the figure, the touch is the minimum value (vmin)
Hereinafter, the mixing ratio of the waveform data A and the waveform data B is 0.9 to 0.1. In addition, the touch is the maximum value (vma
x) Above, the mixture ratio of waveform data A and waveform data B is 0.1 to 0.9.

For example, when the touch intensity is v1 in the figure, the ratio of the amplitude component A and the amplitude component B to be mixed is 0.4 to 0.6, that is, 2 to 3, and the phase component is A
And the ratio of the phase component B is 0.8: 0.2, that is, 4: 1. That is, the amplitude component and the phase component are combined in different modes (ratio). As in the case of the cross fade curve, various mix tables other than the mix table of FIG. 10 can be considered. Also,
The parameter for determining the mixing ratio is not limited to the strength of the touch, but may be determined based on parameters of other performance data.

In FIG. 8, after the mix table selection processing in step D2, it is determined whether or not a touch has been detected (step D3). If there is no touch detection,
Immediately, the waveform mixing process ends. If a touch is detected, a waveform mixing process is performed (step D).
4) A storage process is performed (step D5). In the waveform mixing process in step D4, as shown in FIG. 9, the waveform data output from the waveform memory 1 is Fourier-transformed (step E1). Then, the result of the Fourier transform is separated into an amplitude component and a phase component (step E2). Next, the multiplied values for the amplitude component and the phase component are read from the selected mix table according to the touch detection value (step E3). Then, each of the amplitude component and the phase component is multiplied by a multiplication value (step E4).

Next, an inverse Fourier transform is performed by integrating the amplitude component and the phase component (step E5). Then, the inverse Fourier-transformed waveform data is temporarily stored in a predetermined area of the waveform memory 1 (step E6). Next, it is determined whether or not processing of all waveforms has been completed (step E).
7). If the processing of all the waveforms has not been completed, the process shifts to step E1 to execute the above-described processing. When the processing of all the waveforms is completed in step E7, the waveform mixing processing is completed.

As described above, according to the second embodiment,
The Fourier transform unit 2 calculates the 2
Fourier transform is performed on each type of digital signal, and an amplitude spectrum and a phase spectrum are separated for each digital signal. The amplitude mixing unit 6 synthesizes the separated amplitude spectra with each other using a mix table for amplitude components. The phase mixing unit 7 combines the separated phase spectra with each other using a phase component mix table. The inverse Fourier transform unit 5 integrates the combined amplitude spectrum and phase spectrum and performs an inverse Fourier transform to generate one digital signal. Therefore, by performing phase mixing in a mode (ratio) different from that of the amplitude mixing process, a variety of mixing processes can be performed, so that a tone waveform that enhances the effect of morphing can be generated.

In the second embodiment, two digital signals are mixed.
One or more digital signals may be mixed. In this case, the phase mixing can be performed in a mode different from the amplitude mixing process. For example, they can be mixed at different timings, or mixed at different sections. Therefore, even more
A variety of mix processing becomes possible.

Next, a third embodiment of the present invention will be described. FIG. 11 is a block diagram illustrating a configuration of a waveform generator according to the third embodiment. In this figure, the same components as those of the first embodiment shown in FIG. 1 are denoted by the same reference numerals. The feature of this embodiment is that a section setting unit 8 and an output switching unit 9 are provided.

For example, as in the first embodiment, when two types of sampled waveform data stored in the waveform memory 1 are waveform data of one cycle having the same pitch but different timbres, the section is set. Cross-fade processing is performed for all waveforms without specifying. However, when the waveform data stored in the waveform memory 1 extends over a plurality of periods, the waveform data does not necessarily have to be in the entire section, and at least one period can be subjected to Fourier transform and cross-fade processing can be performed.

As shown in FIG. 12A, the waveform memory 1
It is assumed that the cross-fade section of the waveform data A and the waveform data B stored in is stored as a partial section. For example,
As shown in FIG. 12 (2), when the waveform data A is a sine wave and the waveform data B is a triangular wave, and the zero-cross timings are coincident, the section is designated if it is longer than one cycle section. Fourier transform to separate into an amplitude component and a phase component, and each can be cross-fade.
That is, as shown in FIG. 12C, in one cycle of each waveform data represented by hatching, a cross-fade curve for an amplitude component and a cross-fade curve for a phase component are independently selected, and the cross-fade processing is performed. It can be carried out.

Alternatively, as shown in FIG. 13A, when the pitches of the waveform data A and the waveform data B are different from each other and the timings of the zero crossings do not coincide with each other, a section is defined according to the waveform data. Must be specified. Therefore, as shown in FIG. 13 (2), a cross-fade curve for the amplitude component in each of the waveform data A and B, and the waveform data A and B according to the designated section.
A cross-fade curve for each phase component is selected.

That is, the section setting section 8 in FIG.
Are the waveform data A and B output from the waveform memory 1
Are divided into a path for outputting to the Fourier transform unit 2 and a path for directly outputting to the output switching unit 9 without performing Fourier transform. Although not shown in the figure, a timing control signal for designating a section is given from the CPU to each unit.

Next, the operation of the cross-fade processing in the third embodiment will be described with reference to the flow charts of FIGS. FIG. 14 is a flowchart of the waveform synthesis process in the main routine. In this processing, waveform designation selection is performed according to an instruction from the operation unit or program data (step F1), and cross-fade curve selection processing is performed (step F2). Next, it is determined whether or not it is a cross-fade section (step F3). If it is a cross-fade section, the waveform data A and the waveform data B are output to the Fourier transform unit 2 to perform a waveform cross-fade process (step F4), and a storage process (step F5). On the other hand, if it is not a cross-fade section, the processing of steps F4 and F5 is not performed, and
This flow ends. In this case, the waveform data A and the waveform data B are output to the output switching unit 9. The output switching unit 9 selectively outputs the waveform data synthesized by the cross-fade processing or the waveform data A or the waveform data B in response to the output switching signal from the CPU.

In the waveform cross-fade processing in step F4, as shown in FIG. 15, the address of the waveform data in the selected cross-fade section is designated and Fourier transform is performed (step G1). Then, the result of the Fourier transform is separated into an amplitude component and a phase component (step G2). next,
The amplitude components are combined with each other in accordance with the amplitude component crossfade curve (step G3). Further, the phase components are combined with each other in accordance with the phase component cross-fade curve (step G4).

Next, the combined amplitude component and phase component are integrated and subjected to inverse Fourier transform (step G5). And
It is temporarily stored in the waveform memory 1 (step G6). Next, it is determined whether or not all the cross-fade processes in the designated section have been completed (step G7). If not completed, the process proceeds to step G1 to execute the above-described processes. When the cross-fade processing for all sections is completed in step G7, the waveform cross-fade processing is completed.

As described above, according to the third embodiment,
Fourier transforms two kinds of digital signals in a designated section, separates an amplitude spectrum and a phase spectrum for each digital signal, combines the separated amplitude spectra with each other by a cross-fade curve for an amplitude component, and separates the separated phases. The spectra are synthesized by a cross-fade curve for a phase component, and the synthesized amplitude spectrum and phase spectrum are integrated to generate one digital signal. In this case, the amplitude component and the phase component are combined in different modes. Therefore, as in the case of the first embodiment, it is possible to generate a musical tone waveform that enhances the morphing effect.

Further, according to the third embodiment, even when the waveform data stored in the waveform memory 1 extends over a plurality of cycles, the waveform data is not limited to all the sections, but may be any section including at least one cycle. Cross-fade processing can be performed by Fourier transform.

Next, a fourth embodiment of the present invention will be described. FIG. 16 is a block diagram illustrating a configuration of a waveform generator according to the fourth embodiment. In this figure, components having the same configuration as that of the second embodiment shown in FIG. 7 are denoted by the same reference numerals. Also, components having the same configurations as the section setting unit 8 and the output switching unit 9 of the third embodiment shown in FIG. 11 are denoted by the same reference numerals.

That is, the configuration of FIG. 16 is an embodiment of the mixing process when a section is specified. Waveform memory 1
Are output to the Fourier transform unit 2 through the section setting unit 8 within the designated section. In the Fourier transform unit 2, the waveform data A and the waveform data B are subjected to Fourier transform, and then separated into an amplitude component and a phase component. And the amplitude mixing unit 6
Synthesizes the amplitude components. Further, the phase mixing unit 7 combines the phase components. The mixing ratio in this case is also determined by the mix table according to the strength of the touch, as in the case of the second embodiment.

Further, in the inverse Fourier transform unit 5, the combined amplitude component and phase component are integrated and subjected to inverse Fourier transform, and output to the output switching unit 9 as one digital signal. On the other hand, if it is not the designated section, the waveform data A and the waveform data B output from the waveform memory 1
Is output directly to the output switching unit 9.

As described above, according to the fourth embodiment,
Fourier transforms two types of digital signals in a designated section, separates an amplitude spectrum and a phase spectrum for each digital signal, combines the separated amplitude spectra with a mix table for amplitude components, and separates the separated phase spectrum. These are combined using a phase component mix table, and the combined amplitude spectrum and phase spectrum are integrated to generate one digital signal. In this case, the amplitude component and the phase component are combined in different modes. Therefore, similarly to the case of the second embodiment, it is possible to generate a musical tone waveform that enhances the morphing effect.

Further, according to the fourth embodiment, even when the waveform data stored in the waveform memory 1 extends over a plurality of cycles, the waveform data is not limited to all the sections, but may be any section including at least one cycle. It can be Fourier transformed and mixed.

Next, a fifth embodiment of the present invention will be described. FIG. 17 is a block diagram showing the configuration of the waveform generator according to the fifth embodiment. In this figure, FIG.
The same components as those of the third embodiment shown in FIG. 1 are denoted by the same reference numerals. In FIG. 17, waveform data A and waveform data B output from waveform memory 1 in response to a waveform reading instruction from the CPU are first input to envelope separation unit 10. The envelope separation unit 10 separates the envelope data from each of the waveform data A and the waveform data B, and inputs the waveform data A and B and the envelope data A and B to the section setting unit 8. That is, the envelope separation unit 10 and the CPU (not shown)
Constitutes an envelope separating means.

The section setting section 8 outputs these input data to different routes according to before, within, and after the designated section. That is, the waveform data A and B in the section
Is input to the Fourier transform unit 2, and the waveform data A before the section and the waveform data B after the section are input to the output switching unit 11. Also, the envelope data A in the section
And B are input to the envelope crossfade unit 12, and the envelope data A before the section and the envelope data B after the section are input to the output switching unit 13. In this case, the envelope crossfade unit 12 and the CPU constitute an envelope synthesizing unit.

The Fourier transform unit 2 performs a Fourier transform on the waveform data A and B in the section, and separates each waveform data into an amplitude component and a phase component. The amplitude components A and B are input to the amplitude crossfade unit 3, and the phase components A and B are input to the phase crossfade unit 4. The amplitude component subjected to cross-fade processing in the amplitude cross-fade unit 3 and the phase component subjected to cross-fade processing in the phase cross-fade unit 4 are input to the inverse Fourier transform unit 5. The inverse Fourier transform unit 5 integrates the amplitude component and the phase component, performs inverse Fourier transform to generate one digital signal, and outputs the digital signal.
Enter 1

The output switching section 11 selects one of the waveform data A before the section, the integrated waveform data within the section, and the waveform data B after the section in accordance with a timing control signal from a CPU (not shown). To the envelope synthesizing unit 14.

On the other hand, the envelope crossfade section 12
The envelope data A and B in the section input to
The signal is subjected to crossfade processing and input to the output switching unit 13. The output switching section 13 selects one of the envelope data A before the section, the envelope data synthesized by the cross-fade processing within the section, and the envelope data B after the section in accordance with the timing control signal. Input to 14.

The envelope synthesizing unit synthesizes the waveform data input from the output switching unit 11 and the envelope data input from the output non-switching unit 13 and stores them in a predetermined area of the waveform memory 1.

Next, the waveform synthesizing process according to the fifth embodiment will be further described with reference to FIGS. FIG.
First, a waveform designation selection process is performed (step H).
1). For example, two types of original waveform data A having different frequencies (pitch) and different envelopes as shown in FIG.
And B. Next, the envelope separation section 10 performs an envelope separation process (step H2).
FIG. 20 (2) shows the amplitude envelope data A and B separated from the original waveform data A and B. Next, a cross fade curve is selected (step H3). FIG.
(3) shows the selected crossfade curve.

Then, an envelope crossfade process is performed (step H4). In this process, as shown in FIG. 19, envelope data is cross-fade in sections and in a manner corresponding to the selected cross-fade curve (step J1). FIG. 20 (4) shows waveforms during the cross-fade processing of the envelope data A and B corresponding to the cross-fade curve, respectively, and FIG. 20 (5).
Is a waveform of the envelope data synthesized after the crossfade processing is completed. The synthesized envelope data is temporarily stored (step J2), and the process returns to the flow of FIG.

In FIG. 18, after the envelope crossfade in step H4, a waveform crossfade process is performed (step H5). This crossfade process
This is the same as the flow in FIG. Next, the waveform data and the envelope data are combined by the envelope combining unit 14 (step H6), and a storage process for storing the data in the waveform memory 1 is performed (step H7).

As described above, according to the fifth embodiment, 2
Envelope data is separated from the digital signal of the type and output to a path corresponding to the inside, before, and after the designated section. The digital signal in the section is Fourier transformed,
Separate the amplitude spectrum and the phase spectrum for each digital signal, combine the separated amplitude spectra with each other using the cross-fading curve for the amplitude component, and combine the separated phase spectra together using the cross-fading curve for the phase component, and combine them. The obtained amplitude spectrum and phase spectrum are integrated. Also, as for the separated envelope data, the envelope data in the section is synthesized by an envelope cross-fade curve.
Then, the digital signal in the section and before and after the section is combined with the envelope data in the section and before and after the section to generate one digital signal. In this case, the amplitude component, the phase component, and the envelope component are combined in different modes. Therefore, similarly to the first and third embodiments, it is possible to generate a musical tone waveform that enhances the morphing effect.

Next, a sixth embodiment of the present invention will be described. FIG. 21 is a block diagram illustrating a configuration of a waveform generator according to the sixth embodiment. In this figure, FIG.
The same components as those of the fourth embodiment shown in FIG. Also, components having the same configuration as the output switching units 11 and 13 of the fifth embodiment shown in FIG. 17 are denoted by the same reference numerals.

That is, the configuration shown in FIG. 21 is an embodiment of the mixing process in which the section is specified when the envelope data is separated. Therefore, an envelope mixing unit 15 for mixing the envelope data separated from the two waveform data A and B is provided. That is, the envelope mixing unit 15 and the CPU constitute an envelope synthesizing unit. The envelope data mixed by the envelope mixing unit 15 is input to the output switching unit 13.

Next, a waveform synthesizing process according to the sixth embodiment will be described with reference to the flowcharts of FIGS. In FIG. 22, a waveform designation process is performed (step K).
1) The envelope separation unit 10 performs an envelope data separation process (step K2). Next, a mix table selection process is performed (step K3). And
It is determined whether or not a touch has been detected (step K
4). If no touch is detected, this flow ends. If a touch is detected, an envelope mix process is performed (step K5).

This envelope mixing process is performed as shown in FIG.
As shown in (1), an envelope multiplication value corresponding to the touch detection value is read from the selected mix table (step L1). Then, the separated envelope data is multiplied by a multiplication value. Then, the value is temporarily stored temporarily (step L2), and the process returns to the flow of FIG.

In FIG. 22, after the envelope mixing process at step K5, a waveform mixing process is performed (step K6). In this waveform mixing process, as shown in FIG. 24, the waveform data of the selected section is designated, and the waveform data output from the waveform memory 1 is Fourier-transformed (step M1). Then, the result of the Fourier transform is separated into an amplitude component and a phase component (step M2). Next, the multiplied values for the amplitude component and the phase component are read from the selected mix table according to the touch detection value (step M3). Then, a multiplication value is multiplied by each of the amplitude component and the phase component (step M4).

Next, an inverse Fourier transform is performed by integrating the amplitude component and the phase component (step M5). Then, the inverse Fourier-transformed waveform data is temporarily stored in a predetermined area of the waveform memory 1 (step M6). Next, it is determined whether or not all the processes in the section have been completed (step M
7). If all the processes in the section have not been completed, the process shifts to step M1 to execute each of the above processes. When all the processes in the section are completed in step M7, the waveform mixing process is completed, and the process returns to the flow in FIG.

In FIG. 22, after the waveform mixing process in step K6, a synthesis process of waveform data and envelope data is performed (step K7). Next, a storage process is performed (step K8), and the flow of the waveform mixing process ends.

As described above, according to the sixth embodiment,
Envelope data is separated from a plurality of types of digital signals and output to a path corresponding to a specified section, before a section, or after a section. The digital signals in the section are Fourier-transformed, the amplitude spectrum and the phase spectrum are separated for each digital signal, and the separated amplitude spectra are combined with the amplitude component mix table, and the separated phase spectra are combined with the phase component. And a combined amplitude spectrum and phase spectrum are integrated. As for the separated envelope data, the envelope data in the section is synthesized by an envelope mix table. And
The digital signal in the section and before and after the section is combined with the envelope data in the section and before and after the section to generate one digital signal. In this case, the amplitude component, the phase component, and the envelope component are combined in different modes. Therefore, similarly to the second and fourth embodiments, it is possible to generate a musical tone waveform that enhances the morphing effect.

In each of the above embodiments, the cross-fade processing and the mix processing are executed separately by independent structures. However, the cross-fade processing and the mix processing can be performed separately. Is also good.
In this case, either the cross-fade process or the mix process is selected according to the user's settings.

[0062]

According to the present invention, a plurality of types of digital signals are subjected to Fourier transform, an amplitude spectrum and a phase spectrum are separated for each digital signal, and the separated amplitude spectra are combined in an amplitude component mode. At the same time, the separated phase spectra are combined with each other in a mode for the phase component, and the combined amplitude spectrum and phase spectrum are integrated to generate one digital signal. In this case, the amplitude component and the phase component are combined in different modes. Therefore, it is possible to generate a musical sound waveform that enhances the morphing effect.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration according to a first embodiment of the present invention.

FIG. 2 is a flowchart of a main routine of a CPU common to the first to sixth embodiments;

FIG. 3 is a flowchart of a waveform synthesis process according to the first embodiment.

FIG. 4 is a flowchart of a waveform crossfade process in step B3 of FIG. 3;

FIG. 5 is a view showing a cross fade curve in the first embodiment.

FIG. 6 is a view showing various crossfade curves in the first embodiment.

FIG. 7 is a block diagram showing a configuration according to a second embodiment of the present invention.

FIG. 8 is a flowchart of a waveform synthesis process according to the second embodiment.

FIG. 9 is a flowchart of a waveform mixing process in step D3 of FIG. 8;

FIG. 10 is a diagram showing contents of a mix table in the second embodiment.

FIG. 11 is a block diagram showing a configuration according to a third embodiment of the present invention.

FIG. 12 is a diagram illustrating a cross fade section according to the third embodiment.

FIG. 13 is a diagram illustrating a cross-fade section according to the third embodiment.

FIG. 14 is a flowchart of a waveform synthesis process according to the third embodiment.

FIG. 15 is a flowchart of a waveform crossfade process in step F4 of FIG. 14;

FIG. 16 is a block diagram showing a configuration according to a fourth embodiment of the present invention.

FIG. 17 is a block diagram showing a configuration according to a fifth embodiment of the present invention.

FIG. 18 is a flowchart of a waveform synthesis process according to the fifth embodiment.

FIG. 19 is a flowchart of an envelope crossfade process in step H4 of FIG. 18;

FIG. 20 is a view showing an example of crossfade processing in the fifth embodiment.

FIG. 21 is a block diagram showing a configuration according to a sixth embodiment of the present invention.

FIG. 22 is a flowchart of a waveform synthesis process according to the sixth embodiment.

FIG. 23 is a flowchart of an envelope mixing process in step K5 of FIG. 22;

FIG. 24 is a flowchart of a waveform mixing process in step K6 of FIG. 22;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Waveform memory 2 Fourier transform part 3 Amplitude cross fade part 4 Phase cross fade part 5 Inverse Fourier transform part

Claims (11)

[Claims] 1. Fourier transform means for performing a Fourier transform on a plurality of types of digital signals used as sound sources, and spectrum separating means for separating an amplitude spectrum and a phase spectrum of each of the Fourier-transformed digital signals. An amplitude spectrum synthesizing unit for synthesizing the separated amplitude spectra of the plurality of types of digital signals in a set mode; and a mode in which the separated phase spectra of the plurality of types of digital signals are separated from the amplitude spectrum synthesizing unit. A waveform generating apparatus, comprising: a phase spectrum synthesizing unit that synthesizes in a manner; and a spectrum integrating unit that integrates a synthesized amplitude spectrum and a synthesized phase spectrum to generate one digital signal. 2. The method according to claim 1, wherein the amplitude spectrum synthesizing unit and the phase spectrum synthesizing unit perform cross-fade processing in which a fade-out of at least one kind of digital signal and a fade-in of at least one other kind of digital signal overlap. The waveform generator according to claim 1, wherein a spectrum and the phase spectrum are combined. 3. The method according to claim 1, wherein the amplitude spectrum synthesizing unit and the phase spectrum synthesizing unit synthesize the amplitude spectrum and the phase spectrum by a mixing process in which the plurality of types of digital signals are mixed. The waveform generator according to the above. 4. The cross-fade processing in which a fade-out of at least one kind of digital signal and a fade-in of at least one other kind of digital signal overlap with each other, 2. The waveform generating apparatus according to claim 1, wherein any one of mixing processes in which a plurality of types of digital signals are mixed is executed according to a setting, and the amplitude spectrum and the phase spectrum are combined. 5. The waveform generator according to claim 1, wherein said amplitude spectrum synthesizing means and said phase spectrum synthesizing means synthesize at different timings. 6. The waveform generating apparatus according to claim 1, wherein said amplitude spectrum synthesizing means and said phase spectrum synthesizing means synthesize in different sections. 7. The waveform generating apparatus according to claim 1, wherein said amplitude spectrum synthesizing means and said phase spectrum synthesizing means synthesize at different ratios. 8. The apparatus according to claim 5, wherein said amplitude spectrum synthesizing means and said phase spectrum synthesizing means synthesize in a manner that changes in accordance with input performance data.
8. The waveform generator according to any one of 7 above. 9. The method according to claim 1, wherein an envelope separating unit for separating the amplitude envelopes of the plurality of digital signals, and the separated amplitude envelopes are used as the amplitude spectrum synthesizing unit and the phase spectrum. A waveform generator, further comprising: an envelope synthesizing unit that synthesizes in a mode different from the mode of the synthesizing unit. 10. The spectrum integration means according to claim 1, wherein said one digital signal generated is stored in a predetermined waveform storage means for use as a new sound source. Waveform generator. 11. The Fourier transform unit reads out the plurality of types of digital signals from the waveform storage unit and performs a Fourier transform, and the signal generation unit reads the plurality of types of digital signals stored in the waveform storage unit. 11. The waveform generator according to claim 10, wherein a signal is rewritten and changed to the one generated digital signal.