JP2003173190A - Waveform compressing method and waveform generating method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To compress and synthesize a sound including non-integral harmonics with high compressibility and a high quality. <P>SOLUTION: When an original waveform about a sound including non-integral harmonics, namely an anharmonic sound, is supplied, this original waveform is sorted to a basic harmonic component consisting of a combination of a basic wave and one or more harmonics and a higher-order harmonic components consisting of a combination of other harmonics. Then, processing for vector quantization is performed to each of the basic harmonic component and the higher-order harmonic components to generate compressed data about each component. Thus, many kinds of anharmonic sounds can be recorded even with a small storage capacity by sorting the anharmonic sounds into at least the basic harmonic component and the higher-order harmonic components and then by data-compressing them, and a high quality anharmonic sound can simply be generated by using these pieces of data. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waveform compression method for compressing waveforms of various sounds such as musical tones and voices by using vector quantization technology, and an arbitrary waveform using such waveform compression method. The present invention relates to a waveform generation method for generating, and particularly to an improved waveform compression method so that a sound including a non-integer overtone component can be compressed and synthesized with a high compression rate and high quality. INDUSTRIAL APPLICABILITY The present invention is applicable not only to electronic musical instruments, but also to automatic playing devices, computers, electronic game devices, and other multimedia devices in any field or device or method of any field having a function of generating a musical sound or voice or any other sound. It can be applied in a wide range. In this specification,
The musical tone waveform is not limited to a musical sound waveform, and is used in the sense that it may include a waveform of voice or any other sound.

[0002]

2. Description of the Related Art In a waveform memory, PCM (pulse code modulation), DPCM (differential PCM) or ADPC
Waveform data encoded by an encoding method such as M (adaptive difference PCM) is stored, and the tone waveform is formed by reading the waveform data corresponding to a desired pitch.
The so-called "waveform memory read" technique is already known, and various types of "waveform memory read" techniques are known. Previously known "waveform memory read"
In the technology, there is one for generating a waveform of one sound from the start to the end of sound generation.As such, one sound from the start to the end of sound generation is divided into an attack part and a loop part, and each waveform data is a waveform table. There is an attack-loop type waveform memory sound source that is stored in. In this attack-loop type waveform memory sound source, all waveform data in the attack section, which is a rising section in which the change of the sound immediately after the start of sound generation is complicated, is stored, and the sound decay section that does not change much thereafter is stored. For the sustaining section, the one or more predetermined loop waveforms are stored (a section in which only such loop waveforms are stored is called a loop section). Further, in the conventional attack-loop type waveform memory sound source, when the waveform data is stored in the waveform table, the data is compressed and then stored. As described above, if a large number of waveform data are stored as they are, the memory storage capacity required for data storage will increase considerably. Therefore, in the sustain section, only the loop waveform may be stored or data may be compressed. By doing so, the memory storage capacity of the waveform table necessary for storing the waveform data is saved. In this specification, the term “loop waveform” is used to mean a waveform that is repeatedly read (that is, loop read).

[0003]

By the way, in the above-mentioned attack-loop type waveform memory tone generator, the tone color swells over time (that is, the tone color fluctuates) like a musical tone played by a natural musical instrument such as a piano or a guitar. Occur)
Sounds with unique characteristics that change like (that is, sounds that contain non-integer harmonic components, and such sounds are called anharmonic tones)
In order to realize the above, a method of realizing the loop part with only one wave is conventionally known. The method of realizing this loop part with only one wave (such a loop part is called a short loop) is a method used when it is necessary to increase the data compression rate because a large amount of waveform memory storage capacity cannot be secured. is there. In the case of non-harmonic tones, the one-wave loop cannot be removed as it is, and noise is generated. Therefore, use the one processed so that the one-wave loop can be taken by analyzing and synthesizing the phases of the higher harmonics in advance. . However, in the method of realizing such a loop part with one wave (short loop), especially in the sustain part realized by repeatedly reproducing the loop part, there is no disharmonious feeling, and
Since monotonous sounds are synthesized, there is a problem that it is difficult to reproduce a sound with anharmonic feeling (that is, anharmonic sound) that is a characteristic of natural musical instruments such as a piano and a guitar.

Therefore, in order to solve the problem that occurs in the method of realizing such a loop portion with only one wave (short loop), a method of realizing the loop portion with a plurality of waves has been conventionally known. The method of realizing this loop part with multiple waves (such a loop part is called a long group) is to reproduce a waveform with a harmonious feeling by repeatedly playing a waveform for a certain long time (for example, several hundred milliseconds to several seconds). It is a method that allows. Since this method is close to reproducing the original waveform of the recorded sound as it is, it is possible to reproduce a higher quality synthesized sound as compared with the method of realizing the loop portion with one wave (short loop) as described above. it can. However, in the method of realizing such a loop part with a plurality of waves (long group), when the original sound is an attenuated sound with a smooth timbre change, the loop part is repeatedly reproduced to provide periodicity (that is, a long group feeling). There was a problem that the synthetic sound was realized by holding it. In order to make such a long-group feeling unnoticeable, the loop portion may be made long and stored in the waveform table. However, if so, a large-capacity waveform memory storage capacity is required. That is, the data compression rate becomes low, which is inconvenient.

The present invention has been made in view of the above points, and is a waveform compression method capable of compressing and synthesizing a sound containing a non-integer harmonic component, that is, an anharmonic sound with a high compression rate and high quality. And a waveform generation method.

[0006]

According to a first aspect of the present invention, there is provided a method of compressing a waveform, comprising the steps of supplying an original waveform relating to a sound containing a non-integer harmonic component, and at least supplying the supplied original waveform to a fundamental wave. And a harmonic overtone component composed of one or more harmonics, and a higher harmonic component consisting of a combination of other harmonics, and a step of generating compressed data for the classified fundamental harmonic component. And a step of generating compressed data for the classified upper harmonic components.

According to the present invention, it becomes possible to record a large number of original waveforms relating to sounds containing non-integer overtone components, that is, nonharmonic sounds, with the same storage capacity. That is, when an original waveform relating to a sound including a non-integer overtone component to be data-compressed is supplied, this original waveform is used for at least a fundamental overtone component composed of a combination of a fundamental wave and one or more harmonics, and other components. It is classified as an upper harmonic component composed of a combination of harmonics of. Then, processing for vector quantization is performed on each of the classified basic overtone component and higher-order overtone component. In this vector quantization, the basic overtone component and / or the higher harmonic overtone component may be divided into a plurality of sections, and vector quantization may be performed for each of the plurality of sections.
Vector quantization for each of a plurality of sections enables more accurate waveform compression to the original waveform. In this way, the original waveform relating to the sound including the non-integer overtone component is classified into at least the fundamental overtone component and the upper overtone component, and each component is data-compressed by vector quantization, so that many types of non-overtone components can be stored with the same storage capacity. It becomes possible to record a sound including an integer overtone component, that is, a nonharmonic sound. In this regard, to describe in more detail, an anharmonic musical tone has a peculiar inharmonic feeling (beat) due to the frequency of each harmonic component not being an integral multiple of the first harmonic, and this beat is The cycle and size change intricately over time. Since the anharmonic sound has such a property, the anharmonic sound is divided into (at least) two components and compressed to synthesize two kinds of the harmonic sounds having different pitch changes and volume changes. . By adding these two harmonic tones, the above anharmonic characteristics can be almost reproduced, whereby high data compression can be realized and the anharmonic tones can be synthesized.

A waveform generating method according to claim 9 of the present invention is
A step of obtaining compressed data for a fundamental overtone component consisting of a combination of a fundamental wave and one or more harmonics, and generating waveform data of the fundamental overtone component based on the obtained compressed data for the fundamental overtone component; A step of obtaining compressed data for an upper harmonic component composed of harmonics other than the fundamental harmonic component, and generating waveform data of the upper harmonic component based on the obtained compressed data for the upper harmonic component; Combining the generated waveform data of the fundamental overtone component and the generated waveform data of the upper harmonic component to generate a musical tone waveform relating to a sound including a non-integer harmonic component. According to this, the waveform data of the fundamental overtone component, which is a combination of the fundamental wave and one or more harmonics, and the waveform data of the upper harmonic component, which is a combination of the harmonics other than those contained in the fundamental harmonic component, are generated separately. Since a desired musical tone waveform is generated by synthesizing these waveform data, it is possible to easily reproduce a sound including a high-quality non-integer harmonic component, that is, an anharmonic sound.

The present invention can be constructed and implemented not only as the method invention but also as an apparatus invention. Further, the present invention can be implemented in the form of a program of a processor such as a computer or a DSP, and can also be implemented in the form of a storage medium storing such a program.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a block diagram showing an example of a hardware configuration used for implementing the waveform compression method and waveform generation method according to the present invention. The hardware configuration example shown here is configured using a computer,
Here, the waveform compression and waveform generation processing is executed by the computer executing a predetermined program (software) for realizing the waveform compression method and the waveform generation method according to the present invention. Of course, the waveform compression method and the waveform generation method are not limited to the form of computer software, but can be implemented in the form of a microprogram processed by a DSP (digital signal processor), and the form of this type of program is also possible. However, the present invention is not limited to this, and may be implemented in the form of a dedicated hardware device including a discrete circuit, an integrated circuit, a large-scale integrated circuit, or the like. Further, this hardware configuration may take any product application form such as an electronic musical instrument, a karaoke device or an electronic game device or other multimedia equipment, or a personal computer. Note that FIG.
Although the hardware configuration example shown in (1) may have hardware other than these, here, the case where the minimum necessary resources are used will be described.

In the hardware configuration example shown in FIG. 1, a microprocessor unit (CPU) 1, RO
A microcomputer including an M (read only memory) 2 and a RAM (random access memory) 3 controls the operation of the entire apparatus. For the CPU1 as the main control unit of this computer,
A timer 1A, a ROM 2, a RAM 3, a MIDI interface 4, an input operation device 5, a display device 6, a waveform interface 7, an external storage device 8, a communication interface 9, etc. are connected via a bus line 1D (data or address bus etc.). There is. Further, the CPU 1 is connected with a timer 1A that measures an interrupt time in timer interrupt processing (interrupt processing) and various times. That is, the timer 1A counts the sampling time used for waveform recording, and generates a clock pulse given to the CPU 1 as a processing timing command or an interrupt command. The CPU 1 executes a “waveform compression process” (see FIG. 2 which will be described later) in accordance with the processing timing command and the interrupt command.
And FIG. 3) and “waveform generation processing” (see FIG. 6 described later).

The ROM 2 stores various programs and various data executed or referred to by the CPU 1. The RAM 3 is used as a working memory that temporarily stores various data generated when the CPU 1 executes a predetermined program relating to waveform compression or waveform generation, or as a memory that stores the currently executed program and data related thereto. To be done. A predetermined address area of the RAM 3 is assigned to each function and used as a register, a flag, a table, a memory, or the like.

The MIDI interface 4 is a MIDI-standard performance information from an external MIDI keyboard module or sequencer (that is, an automatic performance device) connected to the device or other equipment (not shown) such as another computer or electronic musical instrument. This is an interface for inputting (that is, MIDI data) to the device or outputting MIDI data from the device to an external computer, electronic musical instrument, or the like. The various external devices connected to the MIDI interface 4 may be devices that generate MIDI data in response to a user's operation, and may be of any type such as keyboard type, string instrument type, wind instrument type, percussion instrument type, body-worn type. It may be a device equipped with an operator (or composed of an operation form). By including such a MIDI interface 4, the device can generate a waveform according to MIDI data input from various external devices. The MIDI interface 4 is a dedicated MIDI interface.
Not limited to those using an interface, RS-232
C, USB (Universal Serial Bus), IEEE
The MIDI interface 4 may be configured using a general-purpose interface such as E1394 (eye triple Ethernet 1394). In this case, data other than MIDI data may be transmitted / received at the same time. MI
When a general-purpose interface as described above is used as the DI interface 4, various external devices are MID
Data other than the I data may be transmitted and received.
Of course, the data format for performance information is MIDI
It is needless to say that the data is not limited to the format data, and other formats may be used, and in that case, the MIDI interface 4 and various external devices are configured accordingly.

The input operation device 5 is configured to include various operators for inputting control information, character information and the like necessary in the process of waveform compression processing and waveform generation processing. For example, a numeric keypad for inputting numerical data, a keyboard for inputting character data, a mouse used for operating a predetermined pointing device displayed on the display device 6, or a keyboard type, string instrument type, wind instrument type, percussion instrument type, body-worn type It is an operator such as a mold. Of course, in addition to various operators for inputting such control information and character information, various operators for selecting / setting / controlling pitch, tone color, effects, etc. may be included.

The display device 6 is a display such as a liquid crystal display panel (LCD) or a CRT for displaying various information input by the input operation device 5 and sampled waveform data. That is, in the display device 6, in the process of waveform compression processing and waveform generation processing, C
Various graphic screens are displayed according to an instruction from the PU 1. For example, you can graphically display the shape of the recorded waveform, graphically display the waveform edit state during waveform compression processing, and control screens for various data settings and selections such as tone settings, tone edits, and system settings. It is used in various ways such as displaying or.

The waveform interface 7 receives an analog waveform signal (that is, an audio signal) externally input via a microphone or the like in response to an instruction from the CPU 1.
A waveform input function of sampling at a predetermined sampling frequency to convert it into a digital signal and sending it to the communication bus 1D, and digital waveform data generated based on compressed data by the waveform generation processing executed by this computer via the communication bus 1D It has a waveform output function and the like for receiving and receiving, converting to an analog waveform signal according to a predetermined sampling frequency and outputting to an speaker system (not shown) or the like.

The external storage device 8 stores compressed waveform data generated according to the waveform compression processing according to the present invention, data relating to control such as various control programs executed by the CPU 1, and the like. For example, when the control program is not stored in the ROM 2, the control program is stored in the external storage device 8 (for example, hard disk), and the program is loaded into the RAM 3 to read the R program.
The CPU 1 can be caused to perform the same operation as when the control program is stored in the OM 2. By doing so, it is possible to easily add or upgrade the control program. The external storage device 8 is a hard disk (H
Not limited to D), a flexible disk (FD), a compact disk (CD-ROM / CD-RW), a magneto-optical disk (MO), or a DVD (Digital Versatil).
Any storage device may be used as long as it uses various removable external storage media such as an e Disk). It may be a semiconductor memory or the like.

The communication interface 9 is connected to a wired or wireless communication network X such as a LAN, the Internet or a telephone line, and is connected to an external host or server computer (not shown) via the communication network X. , An interface for fetching various data such as a control program, compressed waveform data, and original waveform from the host or server computer into the device. That is, the ROM 2 and the external storage device 8
It is used to download the control program and various data from an external host or server computer when the control program and various data are not stored in (for example, a hard disk). The device as a client transmits a command requesting the download of a control program or various data to an external host or server computer via the communication interface 9 and the communication network X. The external host or server computer receives this command and distributes the requested control program and various data to this device via the communication network X, and this device transmits these control programs and various data via the communication interface 9. The download is completed by receiving the data and storing it in the external storage device 8 (for example, hard disk) or the like. The communication interface 9 and the communication network X are not limited to wired ones, and may be wireless ones. Also, both may be provided.

The digital waveform data converted and input through the above-mentioned waveform interface 7 is once written in a predetermined storage area in the RAM 3, the external storage device 8 or the like, and the input waveform data is instructed by the CPU 1 according to the instruction. A predetermined waveform compression process (described later) according to the present invention is performed. The compressed data is stored in an appropriate waveform database (also called a waveform memory). In this case, not only the analog waveform signal but also digital waveform data may be input via the communication interface 9 or the like, and the input waveform data may be subjected to required data compression. The function of the waveform database may be handled by any type of data storage device. That is, the above RA
Either M3 or the external storage device 8 may function as the waveform database. Generally, the external storage device 8, which is a large-capacity storage device, may function as a waveform database. Alternatively, a waveform database provided in an external host or server computer is accessed via the communication interface 9 and a communication network to write compressed data there, or to store compressed data required for reproduction externally. Device 8 or RAM3
You may make it download it to the etc. At the time of waveform generation, a predetermined waveform generation process (described later) is performed using the compressed data stored in the waveform database to generate digital waveform data. The generated digital waveform data may be output as an analog signal via the waveform interface 7 as described above, or may be transferred and output as digital data to the outside via the communication interface 9 or the like. When an external memory such as an external storage device 8 or an external host or server computer is used as the waveform database, an internal transfer buffer (RAM 3 or the like) is provided in order to quickly access the specified waveform data. It is preferable to transfer all or a part of the waveform database to the above.

The devices shown in the above-described embodiments are not limited to those having the input operation device 5, the display device 6, the external storage device 8 and the like built into one device body, and each of them is configured separately and the MIDI device is used. It goes without saying that it may be configured to connect the respective devices using a communication means such as an interface or various networks.
In implementing the present invention, the computer system as shown in FIG. 1 does not necessarily have to have both the functions of the waveform compression processing and the waveform generation processing, and only one of them can be implemented. It may be configured.

As described above, the digital waveform data converted and input through the waveform interface 7 is stored in the RAM.
3 or is temporarily stored by being once written in a predetermined storage area in the external storage device 8 or the like. Compressed data is generated by subjecting the temporarily stored waveform data to a predetermined waveform compression process in accordance with an instruction from the CPU 1. The generated compressed data is stored in an appropriate waveform database. In this way, by storing the waveform data after compressing it, the storage capacity of the waveform memory necessary for storing the waveform data is saved. Therefore, an embodiment of such waveform compression processing will be described with reference to FIG. FIG. 2 is an equivalent block diagram schematically showing the procedure of the waveform compression processing executed under the control of the CPU 1. However, in this embodiment, the digital waveform data temporarily stored in the RAM 3, the external storage device 8 or the like is anharmonic as an analog waveform signal for each single tone obtained by actually playing various natural musical instruments such as a piano and a guitar. It is data converted into a digital signal by sampling sound according to a predetermined sampling frequency.

First, in the "inharmonic original waveform input" (process P1), waveform data for each single tone temporarily stored in the RAM 3 or the external storage device 8 is selectively read. Of course, even in the case of single notes having the same pitch (or pitch name), the waveform characteristics (that is, timbre) of the performance sound are different for each musical instrument such as piano sound and guitar sound. Therefore, "input anharmonic original waveform" (process P1)
The waveform data to be input in step 3 takes into consideration the difference in waveform characteristics according to these various viewpoints. Therefore, the “waveform data for each single note” can be distinguished and described using, for example, a combination of “instrument name” and “pitch”. In the "input of nonharmonic original waveform" (process P1), tone color designation data composed of the "instrument name" and "pitch" is generated, and the generated tone color designation data is waveform information assigned to a predetermined area of the RAM 3, for example. It is stored in the storage unit M3. The tone color designation data stored in the waveform information storage unit M3 is used as index information of the compressed data generated by the processes P2 to P5 for waveform data compression.

Next, in the "component separation by frequency analysis" (process P2), the waveform data of a single tone read in the above "input of nonharmonic original waveform" (process P1) is used as the fundamental overtone component and the upper overtone. A process of separating into a component and a noise component is performed. That is, as will be described later, in the anharmonic sound, all the harmonics (harmonics) are inharmonic with respect to the fundamental wave, but if only the fundamental wave is extracted, the sound is a harmonic sound, If only the higher harmonics are taken out, the sound is a sound containing many anharmonic sounds. Therefore, the waveform data of the single tone read out in the "input of non-harmonic original waveform" (process P1) is separated into at least a fundamental overtone component and an upper overtone component. As an example of this separation processing, first, the waveform data to be separated is input, and frequency analysis (spectral analysis) is performed on this waveform data by Fast Fourier Transform (FFT) to obtain its fundamental frequency component and harmonic components (that is, overtone components). And extract. Of the fundamental frequency components and harmonic components extracted in this way, for example, the fundamental frequency component, the second harmonic (2nd harmonic) component, and the third harmonic (3rd harmonic) component are fundamental harmonic components, and the other fourth harmonic components. All extracted harmonic components are separated into any of the harmonic components equal to or higher than the wave (4th harmonic) as upper harmonic components. Further, the fundamental overtone component waveform and the upper overtone component waveform are respectively subjected to inverse Fourier transform to generate the fundamental overtone component waveform and the upper overtone component waveform. Then, a noise component waveform is obtained as a result of the calculation by performing a predetermined calculation process (for example, a subtraction process) with the input waveform to be separated using the basic harmonic component waveform and the upper harmonic component waveform.

FIG. 3 shows an example of frequency analysis processing by the above-mentioned fast Fourier transform (FFT). This Figure 3
It is a conceptual diagram which showed one Example of the frequency analysis result performed in "component separation by a frequency analysis" (process P2). In this example, the vertical axis represents frequency (pitch) and the horizontal axis represents time. The wavy curve in this figure shows the frequency at each harmonic, and the straight line conveniently indicates the fundamental frequency (0.35 kHz in this embodiment) and each predetermined integral multiple of the fundamental frequency. The frequency scale is shown at even intervals. That is, each curve represents a temporal change in the pitch of each overtone. In this embodiment, a curve showing the frequency of the 10th harmonic (3.5 kHz) is 3.5.
An example is shown in which the lines are displayed so as to overlap with each other on the straight line indicating kHz (that is, the case where tuning is performed with 10 harmonics).

As can be understood from FIG. 3, when frequency analysis is performed on the nonharmonic tones, the pitch of each harmonic overtone lower than the tuned tenth overtone appears lower than the corresponding frequency scale, and the harmonic overtone higher than the tenth harmonic overtone appears. The pitch of each overtone appears higher than the corresponding frequency scale. In other words, if the frequency analysis target sound is a harmonic sound, the pitches of all harmonic overtones would appear to overlap each other on the corresponding frequency scale, but if the frequency analysis target sound is a nonharmonic sound. , The pitch of each overtone appears to be shifted from the corresponding frequency scale. This is the case when any desired overtone pitch is adjusted to the corresponding frequency scale, which is a characteristic of anharmonic tones. In this way, the pitch of each harmonic overtone does not correspond to the frequency of a perfect integer multiple of the corresponding fundamental frequency of the musical instrument sound played from a natural instrument such as a piano or a guitar. There is a slight deviation from the fundamental frequency, which is an integral multiple of the fundamental frequency, that is, a sound that contains non-integer harmonic components. Further, in a natural musical instrument, it is unlikely that a completely constant frequency and intensity are maintained during the production of one note, so that the irregular curve as shown in the curve in FIG. It usually contains fluctuations. Therefore, it is very important to be able to reproduce such “deviation / fluctuation” in order to express with high quality the musical instrument sound played from a natural musical instrument such as a piano or a guitar.

Returning to FIG. 2, in the "basic harmonic overtone component analysis" (process P3), the characteristics of the fundamental overtone component waveform separated and generated from the original waveform in the above "component separation by frequency analysis" (process P2) are described. The analysis is performed, optimal vector quantization processing is performed according to this feature, and compressed data of the fundamental harmonic component waveform that is compressed according to vector quantization is generated. Similarly, in the “upper harmonic component analysis” (process P4), the above “component separation by frequency analysis” (process P) is performed.
2) Analyze the characteristics of the upper harmonic component waveform separated and generated from the original waveform, perform optimal vector quantization according to this characteristic, and generate the compressed data of the upper harmonic component waveform compressed according to the vector quantization. To do. In such "basic overtone component analysis" (process P3) and "upper harmonic component analysis" (process P4), each is divided into a plurality of sections, and vector quantization is performed for each of these plurality of sections.
Waveform compression can be performed more faithfully with the original waveform. When dividing into multiple sections, the characteristics of each part are observed and analyzed considering the position of the fundamental harmonic component waveform of the processing target and the waveform of the upper harmonic component waveform, the characteristics of the waveform shape, etc. The fundamental overtone component waveform and the higher harmonic overtone component waveform are divided into a plurality of waveform sections by dividing the waveform into the appropriate sections. For example, as the position, an “attack part” (a rising part of a sound), a “sustained part” (a stationary part of a sound), etc. are considered. The characteristics of the waveform shape include amplitude envelope shape (its effective value and peak value, etc.), the number of zero crosses or the period between zero crosses, the number of peaks or the period between peaks, the location of the peak value, and multiple peak levels. It is advisable to take into consideration various factors such as the distribution of.

In general, a single tone emitted in response to pressing the keyboard of a piano or playing a string of a guitar is a decaying tone, and includes an attack portion where the sound rises sharply and a sustaining portion where the tone decays over time. Composed of. Since the attack part basically corresponds to a random waveform that does not have repetitiveness, it is necessary to consider the content and where it is located in the sounding period, etc. The required basic harmonic component waveform and the upper harmonic component waveform are reproduced by using the representative vector consisting of the time length only once without looping. On the other hand, since the decaying sustaining portion can be basically regarded as a repetitive waveform, for example, by using a waveform of one cycle or a plurality of cycles as a representative vector, the representative vector is looped (or two representative vectors preceding and following each other). Crossfade loop), it is possible to play such a sustaining part. Therefore, a vector corresponding to the waveform portion of such a representative vector is stored in the basic overtone component tone color vector storage unit M1 as a basic overtone component tone color vector, and is generated by this "basic overtone component analysis" (process P3). As compressed data to be used, vector information for designating the tone color vector stored in the basic overtone component tone color vector storage unit M1 and how to use the designated tone color vector (for example, a section in which the vector is used or a loop period, Alternatively, it is preferable to generate the information including the information describing the form of the envelope to be given to it.

On the other hand, "upper harmonic component analysis" (process P
As the processing procedure of 4), basically the same procedure as the processing procedure of the “basic overtone component analysis” (process P3) shown in FIG. 3 may be used. That is, also in the "upper harmonic component analysis", the same "waveform section division" processing as in the "basic overtone component analysis" may be performed. In that case, vector quantization processing is performed on each divided waveform section. Give. The division of the upper harmonic component waveform may be almost the same as the division of the basic overtone component. Of course, since the waveform section division form of the upper harmonic component is naturally different from the corresponding waveform section division form of the basic overtone component, the basic overtone component and the upper harmonic component may be independently divided. Needless to say.

Next, in the "noise component cutout" (process P5), the waveform data of the noise component separated and generated from the original waveform in the above "component separation by frequency analysis" (process P2) is analyzed to obtain the noise component. Only the waveform of a partial section of the waveform is stored in the noise component storage unit M4. That is,
As for noise components, only waveform data for a short time (for example, about tens to hundreds of milliseconds) immediately after keystroke, string striking or picking is required, so only waveform data corresponding to that time portion is stored as noise components. Store in section M4.
By doing so, the data amount of the noise component waveform stored in the noise component storage unit M4 can be significantly reduced. In some cases, such a noise component may be mixed with the attack portion of either the basic overtone component or the upper overtone component and stored as the basic overtone component or the upper overtone component. In such a case, the noise component is separated by the above-mentioned “component separation by frequency analysis” (process P2) or the noise component is cut out (process P2).
Since it is not necessary to perform the processing such as 5), these can be omitted. Also, regarding the noise component,
Since the data of the noise component itself can be shared, the compression rate may be further reduced by performing such data sharing. For example, since the sound generated when each key of the piano is pressed does not vary greatly from key to key, it is advisable to make such noise sounds common.

In FIG. 2, the waveform information storage unit M3 stores the compressed data (first compressed data) excluding the tone color vector among the compressed data generated in the above-mentioned "basic overtone component analysis" (process P3) and the "upper order". Harmonic component analysis ”(Process P
Among the compressed data generated in 4), the compressed data excluding the tone color vector (second compressed data) is paired with the tone color designation data generated in the "inharmonic original waveform input" (process P1). Is stored as tone color designation information. Therefore, in order to reproduce the waveform, the desired musical instrument name and pitch are used as indexes, and the first harmonic component and the first harmonic component of the corresponding harmonic pitch from the waveform information storage unit M3 are used.
And the second compressed data can be recalled. Also,
According to the above-mentioned musical instrument name and pitch, the predetermined fundamental overtone component tone color vector and the upper overtone component tone color vector are read from the fundamental overtone component tone color vector storage unit M1 and the upper overtone component tone color vector storage unit M2, respectively.
Based on the vector information contained in the called compressed data, the fundamental harmonic component waveform and the upper harmonic component waveform are respectively reproduced, and these two and the noise component waveform are additively combined to form a musical tone waveform of anharmonic sound. Can be generated. Anharmonic musical tones have a unique anharmonic feeling (beat) due to the frequency of each harmonic component not being an integer multiple of the first harmonic, and this beat has a complicated cycle and magnitude with the passage of time after pronunciation. Changes to. Since the anharmonic sound has such a property, the anharmonic sound is divided into (at least) two components and compressed to synthesize two kinds of the harmonic sounds having different pitch changes and volume changes. . By adding these two harmonic tones, the above anharmonic characteristics can be almost reproduced, whereby high data compression can be realized and the anharmonic tones can be synthesized.

Next, the processing of the above-mentioned "basic overtone component analysis" (process P3 in FIG. 3) will be described in detail with reference to FIG. FIG. 4 is a schematic block diagram showing the processing procedure of “basic overtone component analysis”. Note that the process shown in FIG. 4 does not show all of the "basic overtone component analysis" (process P3), and mainly, a new tone color vector of the fundamental overtone component is newly generated, and this is used as a basis. The portion related to the process of accumulating and storing in the overtone component tone color vector storage unit M1 is shown. Although only the "basic overtone component analysis" processing will be described here, the description of the "upper harmonic component analysis" (process P4 in FIG. 3) processing will be omitted because it can be the same. That is, in the following description, the “basic overtone component” part is replaced with the “upper harmonic component” to describe the “upper harmonic component analysis” process.

First, assuming that the "waveform section division" process S1 is performed (which is not an essential process as described above), the above-mentioned "component separation by frequency analysis" (process P in FIG. 2) is performed.
The fundamental overtone component waveform separated and generated from the original waveform in 2) is divided into a plurality of waveform sections. Next, in "vector generation of each waveform section" processing S2, vector quantization processing is performed in each divided section to extract "amplitude vector", "pitch vector" and "tone color vector" for the fundamental overtone component. In extracting a tone color vector, in order to efficiently determine whether the characteristics of the waveform shape for each cycle are common or similar, the waveform is cut out for each cycle of the fundamental frequency, and its pitch and amplitude level are determined. It is advisable to perform common standardization processing so that only the waveform shapes of one period waveform can be compared. In that case, the subsequent tone color vector quantization processing is performed on the waveform data whose pitch and amplitude level are standardized, and the temporal change state of the original pitch and amplitude level with respect to this standardized pitch and amplitude level. "Pitch vector" as a vector
And "amplitude vector" are generated. When this “waveform section division” process S1 is performed, “section information” is generated as information describing the division mode of a plurality of waveform sections,
It is stored corresponding to the vector information.

Explaining in detail the extraction of the tone color vector in the "vector generation of each waveform section" process S2, the representative vector of the waveform data is generated in consideration of the characteristics of the waveform of each divided waveform section. For example, when the same one cycle or a plurality of cycle waveforms are repeated in one waveform section, it is selected as a temporary representative vector for the time being, and the average of the temporary representative vectors of the waveform data in the same waveform section is calculated. An intermediate or most characteristic vector is determined as a representative vector of the group and is generated. The generated representative vector (specifically, the waveform data having one or a plurality of cycles) is stored in the basic overtone component tone color vector storage unit M1 and registered as a tone color vector. In the waveform information storage unit M3, "vector information" for the basic overtone component that specifies one of the tone color vectors stored in the basic overtone component tone color vector storage unit M1 is generated. Since this "vector information" is index data indicating which tone color vector (specifically, waveform data having one or a plurality of cycles) stored in the basic overtone component tone color vector storage unit M1, it is composed of a plurality of bits. Very little data.

The pitch vector and the amplitude vector, which are "vector information" other than the tone color vector, are combined with the "section information" generated from the "waveform section division" process S1 to compress the fundamental overtone component in the waveform section. The data is stored in the waveform information storage unit M3. Therefore, the compressed data for one rendition style section includes a combination of "vector information" and "section information" for each of a plurality of waveform sections obtained by dividing the rendition style section. As described above, the timbre vector is formed by performing vector quantization processing on the waveform data in which the pitch and amplitude level are standardized, and the difference between the standardized pitch and amplitude is calculated as the "pitch vector" and the "amplitude vector", respectively. Is stored in the waveform information storage unit M3.

By performing the period analysis in this way,
An "amplitude vector", a "pitch vector", and a "tone color vector" are extracted for each of the "basic overtone component" and the "upper harmonic component". Since the amplitude vector and the pitch vector are a set of data having one point time and a predetermined value for each analyzed wave, the amount of data stored in the waveform memory is smaller than that of the original waveform itself. For example, 440Hz
The sound in the vicinity has a sufficiently high compression rate of about 1/100 (in the case of 44.1 kHz sampling). It should be noted that the compression rate may be further increased by deleting a redundant part in which similar values continue. The timbre vector adopts a representative vector at a rate of about tens of milliseconds for the attack part and a ratio of about 1 wave to 30 waves for the sustain part, for example. It is possible to achieve a compression ratio of 1 of several tens of minutes. Of course, it goes without saying that the compression rate can be further increased if necessary.

Here, the above-mentioned "waveform compression processing" (see FIG. 2)
Basic harmonic overtones generated by the execution of the reference harmonics stored in each of the waveform databases (that is, the basic harmonic overtone component tone color vector memory M1, the upper harmonic overtone component tone color vector M2, the waveform information memory M3, and the noise component memory M4). FIG. 5 shows an example of each of the component vector data, the upper harmonic component vector data, and the noise component data.
FIG. 5 is a conceptual diagram schematically showing data for each processing execution in the “waveform compression processing”.

First, FIG. 5A is a conceptual diagram schematically showing an example of the input original waveform by an amplitude envelope. This data is shown in Fig. 2 "Inharmonic original waveform input"
This is data relating to the original waveform of the anharmonic sound read out in (Process P1), and this waveform data indicates that the sound has a steep rising edge and is gradually attenuated over time. Such a wavy shape is a shape that often appears when, for example, one keyboard of a piano or one string of a guitar is pressed and played only once.

FIG. 5 (b) shows the separation from the original waveform described above.
It is a conceptual diagram which shows an example of each of the generated fundamental overtone component waveform, upper overtone component waveform, and noise component waveform by an amplitude envelope. These data are used for “component separation by frequency analysis” shown in FIG. 2 (process P2).
Is a waveform generated by the execution of. The fundamental overtone component contains the basic sound characteristics of various musical instruments, and the higher harmonic overtone component contains more of the anharmonic sound characteristics of various musical instruments. When the waveform is frequency-analyzed and the components are separated, the data shown in the upper and middle rows of FIG. Further, the noise component is generated, for example, by a sound generated from the keyboard itself when the keyboard of the piano is pressed, or by rubbing the string and the finger (or the pick) when the guitar string is played with the finger (or the pick). Since it is noise other than the musical instrument sound that is emitted in a short time before the actual musical instrument sound such as sound,
Data generated by the waveform is generated only during a short time of the rising portion of the sound as shown in the lower part of (b).

Next, FIG. 5C is a conceptual diagram showing an example of the basic overtone component vector data, the upper overtone component vector data, and the noise component data, respectively. These data are used for the “basic overtone component analysis” (process P shown in FIG.
3), "upper harmonic component analysis" (process P4) and "noise component cutout" (process P5). In FIG. 5C, the extracted “amplitude vector”, “pitch vector”, and “attack + multiloop waveform” (that is, An example of a tone vector) is shown.

As can be understood from the "amplitude vector" shown in this embodiment, the amplitude of the upper harmonic component converges at a time earlier than the amplitude of the fundamental harmonic component. Also, as can be understood from the "pitch vector" shown in this embodiment, the pitch of the upper harmonic component is completely different from the pitch of the basic harmonic component, and is higher than the pitch of the basic harmonic component as a whole. It is changing over time. This will reproduce the anharmonicity. That is, if the basic overtone component waveform and the upper harmonic overtone component waveform are played back at the same pitch, the inharmonicity cannot be reproduced so much, but the basic overtone component waveform and the upper overtone component waveform are reproduced and generated at slightly different pitches. By mixing the generated waveforms, the detune effect can be easily obtained, and the "deviation / fluctuation" of the frequency of each overtone can be reproduced, so that the synthesized sound becomes a beating sound. As described above, by generating the fundamental overtone component waveform and the upper overtone component waveform using the two types of pitch vectors, it is possible to reproducibly generate high-quality anharmonic tones.

In the "Attack + Multi-loop waveform" shown in this embodiment, the thick line represents the tone color vector. For example, in the waveform section from the time point t0 to t1, a relatively large size (consisting of a multi-cycle waveform) fundamental overtone component tone color vector W1 is used as a tone color vector, and during reproduction, this is from the time point t0 to t1. Is reproduced once in a predetermined period of the beginning of the period, and loop reproduction is appropriately performed in the remaining period (for example, the fundamental harmonic component tone color vector W
Cross-fade loop reproduction is performed between the waveform at the end of 1 and the fundamental overtone component tone color vector W2 in the next section). Further, in the waveform section from the time point t1 to t2, the fundamental overtone component tone color vector W2 is used as a tone color vector, and during reproduction, this is loop-played between the time points t1 and t2 (basic overtone component tone color). Vector W
2 and a basic overtone component tone color vector W3 are crossfade loop reproduced). Thereafter, similarly, the tone color vector is loop-reproduced at each time. Since the same processing as that of the basic overtone component described above may be performed for the upper overtone component, the description of the upper overtone component will be omitted.
Further, as can be understood from the lower diagram of FIG. 5C, the noise component data is obtained by cutting out only the characteristic waveform portion of the noise component waveform shown in the lower diagram of FIG. 5B for a predetermined time. . As described above, since the noise component is noise other than the musical instrument sound emitted in a short time before the actual musical instrument sound is generated, only the waveform in the short time of the rising portion of the sound may be recorded.

Next, the "waveform generation process" for generating a waveform using the basic overtone component vector data, the upper overtone component vector data, and the noise component data shown in FIG. 5C will be described with reference to FIG. explain. FIG. 6 shows an example of a process of reproducing a musical tone, that is, generating a waveform, based on input predetermined performance start information, for example, performance start information according to a keyboard operation by a user or performance start information included in MIDI data prepared in advance. Is schematically shown by an equivalent block diagram. This tone reproduction, that is, waveform generation processing, is performed by using the hardware device of FIG.
This is performed by executing a predetermined software program by PU1.

The "reproduction control" process S10 is performed in response to a performance start instruction input according to a keyboard operation by the user or a performance start instruction input based on MIDI data generated in advance. Various controls are performed to generate a musical tone waveform having a designated pitch and tone color. First, according to predetermined information such as "instrument name" (tone color) and "key number" (pitch) included in the performance start instruction, the fundamental harmonic component tone color vector storage unit M1,
From the upper harmonic component tone color vector storage unit M2 and the waveform information storage unit M3, a vector set for a predetermined waveform that is specified, that is, a basic harmonic component tone color vector, a pitch vector, and an amplitude vector, and an upper harmonic component tone color vector and pitch. A vector and an amplitude vector are selected and read out. As described above, the first compressed data for the fundamental overtone component includes "vector information" indicating the fundamental overtone component tone color vector, "section information", "pitch vector", "amplitude vector", and the like. . Further, the second compressed data for the upper harmonic component includes "vector information" indicating the upper harmonic component tone color vector, "section information", "pitch vector", "amplitude vector", and the like.

In the "basic overtone reading" process S11, the basic overtone component is stored in the upper harmonic overtone component tone color vector storage unit M1 based on "vector information" and "section information" of the first compressed data for the basic overtone component. Read out the tone vector. In the "basic harmonic overtone processing" process S12, based on the basic harmonic overtone component tone color vector read from the basic overtone component tone color vector storage unit M1 and the necessary second compressed data (that is, section information, pitch vector, amplitude vector, etc.), Reproduces / generates the required basic overtone component waveform. That is, the waveform of the basic overtone component tone color vector is appropriately looped (repeated) according to the section information, and the pitch is temporally controlled according to the pitch vector (of course, the basic pitch is the MID
(It is set and controlled according to the key number included in the I data), and its amplitude envelope is set and controlled according to the amplitude vector. The connection of each basic overtone component tone color vector at this time is performed by crossfade synthesis between the two tone color vectors to be connected. Thus
Generate a fundamental harmonic component waveform.

On the other hand, for the upper harmonic component, in the same manner as the basic harmonic component, in the "upper harmonic read" process S13, the "vector information" and the "section" in the second compressed data for the higher harmonic component. Based on the "information", the upper harmonic component tone color vector is read from the upper harmonic component tone color vector storage unit M2. Then, "upper harmonic processing" processing S14
Then, the required upper harmonic component waveform is reproduced based on the upper harmonic component tone color vector read from the upper harmonic vector storage unit M2 and the necessary second compressed data (that is, section information, amplitude vector, pitch vector, etc.).・ Generate.

The compressed data of the upper harmonic component to be reproduced may be vector-quantized by performing interval division in synchronization with the periodicity of the corresponding fundamental harmonic component.
The expansion / contraction control of the waveform on the time axis in this case is performed based on the "vector information".
When the upper harmonic component tone color vector is read from 2 or after the upper harmonic component tone color vector is read, the time length of the upper harmonic component tone color vector is appropriately expanded / contracted according to the cycle of the basic harmonic component to be reproduced at the same time. This is because the reproducibility of the upper harmonic component waveform is improved when the time length of the upper harmonic component tone color vector is expanded / contracted in synchronization with the expansion / contraction of the cycle of the fundamental harmonic component to be reproduced. The time length expansion / contraction control of the upper harmonic component tone color vector is simply performed by changing the reading rate of the upper harmonic component tone color vector storage unit M2 in association with the change of the read cycle (reading rate) of the corresponding basic harmonic component tone color vector. This may be done, or time axis expansion / contraction control may be adopted.

In the "noise reading" process S15, the noise component data is read from the noise component storage unit M4. Since the noise component storage unit M4 stores the waveform data of the noise component itself, the noise component waveform can be reproduced / generated by simply reading the stored noise component data as it is. When reading this noise component data, a constant frequency that is not proportional to the pitch corresponding to the "key number" included in the performance start instruction is used. The fundamental harmonic component waveform thus generated reproduces the acoustic characteristics that form the basis and skeleton of the musical instrument sound, the upper harmonic component waveform reproduces the anharmonic acoustic characteristics, and the noise component waveform reproduces the plucked acoustic characteristics. It is a waveform. In the "mixing" process S16, the basic harmonic component waveform, the upper harmonic component waveform, and the noise component waveform reproduced and generated as described above are mixed, and musical tone waveform data formed by mixing all these components is generated. . The musical tone waveform data thus generated is reproduced and provided (step S17). The reproduced musical tone waveform data may be supplied as it is as digital data to another device, or may be converted into an analog signal and spatially sounded via an appropriate sound system. It should be noted that the signal of the basic overtone component waveform, the signal of the higher harmonic overtone component waveform, and the signal of the noise component waveform may be separately generated, and these may be mixed in space.

In the frequency analysis executed in the above-mentioned "component separation by frequency analysis" (process P2), the fundamental frequency component and the second harmonic component are extracted from the extracted fundamental frequency component and the higher harmonic components. The extracted fundamental frequency component and harmonic components are separated into two components, with the 3rd harmonic component as the "fundamental harmonic component" and all other harmonic components above the 4th harmonic as "upper harmonic components". However, it is not limited to this. For example, up to the second, third, fourth, and fifth harmonic components of the fundamental frequency component and harmonic components are “fundamental overtone components”, and all other harmonic components above the sixth harmonic are “fundamental harmonic components”. You may make it isolate | separate as a "higher harmonic component." Further, in the above-described embodiment, the harmonic components separated into the “upper harmonic components” are all the harmonic components not included in the “fundamental harmonic components”, but the harmonic components within a predetermined range are not limited to this. The wave components may be separated as the “upper harmonic component”. In addition, the user can select the “fundamental overtone component” up to the harmonic component that is within the predetermined range.
The other harmonic components may be appropriately set as the “upper harmonic component”. Also,
You may make it possible to selectively separate only the desired harmonic component as the “fundamental overtone component” or the “upper overtone component”.

Further, in the above-mentioned embodiment, the input waveform is separated into two components, that is, the fundamental overtone component and the upper overtone component. However, the present invention is not limited to this, and it is divided into at least two or more components. May be. For example, the fundamental frequency component, the second harmonic component, and the third harmonic component are “fundamental overtone components”, the fourth, fifth, and sixth harmonic components are “first upper harmonic component”, and the other seven The input waveform may be separated into a plurality of components (three components in this case) by regarding all the harmonic components equal to or higher than the harmonics as “second upper harmonic components” and the like. However, in such a case, it goes without saying that in each of the above-described embodiments, it is necessary to partially change various processes such as “waveform compression process” and “waveform generation process” so as to correspond to each separated component.

The format of the performance information (such as MIDI data) used in the above apparatus is the "event + absolute time" format in which the event occurrence time is represented by the absolute time within the song or measure, and the event occurrence time. 1
"Event + relative time" format, which is the time from the previous event, and "pitch (rest) + note length" that shows performance information in terms of note pitch and note length or rest and rest length. ”Format, a memory area for each minimum resolution of the performance, and a“ solid method ”format in which events are stored in the memory area corresponding to the time when the performance event occurs Good. Further, when there is performance information for a plurality of channels, it may be a format in which data of a plurality of channels are mixed, or a format in which data of each channel is divided for each track.

[0052]

According to the present invention, the original waveform of the anharmonic sound is separated into the fundamental overtone component and the upper overtone component, vector quantization is performed for each component, and the result is stored in the waveform database. Since vector data can be read and synthesized at different pitches for each component during waveform generation, this contributes to improving the waveform compression efficiency, and a detune effect can be easily obtained during waveform generation. Therefore, various excellent effects such as excellent reproducibility of the original waveform, particularly reproducibility of anharmonic sound, and the like are exhibited.

[Brief description of drawings]

FIG. 1 is a block diagram showing an example of a hardware configuration used for implementing a waveform compression method and a waveform generation method according to the present invention.

FIG. 2 is an equivalent block diagram schematically showing a procedure of a waveform compression process executed under the control of a CPU.

FIG. 3 is a conceptual diagram showing an example of a frequency analysis result executed in “component separation by frequency analysis”.

FIG. 4 is a schematic diagram showing an equivalent block diagram of a processing procedure of “basic overtone component analysis”.

FIG. 5 is a conceptual diagram schematically showing data for each processing execution in the “waveform compression processing”, and FIG. 5A is a conceptual diagram schematically showing an example of an original waveform by an amplitude envelope. b) is a conceptual diagram schematically showing an example of basic harmonic overtone component waveforms, upper harmonic overtone component waveforms, and noise component waveforms separated and generated from the original waveform by amplitude envelopes. FIG. 5C shows basic overtone component vector data. It is a conceptual diagram which shows an example of upper harmonic component vector data and an example of noise component data, respectively.

FIG. 6 is an equivalent block diagram schematically showing an example of a process of generating a waveform based on input predetermined performance start information.

[Explanation of symbols]

1 ... CPU, 1A ... Timer, 2 ... Read-only memory (ROM), 3 ... Random access memory (RAM),
4 ... MIDI interface, 5 ... Input operation device, 6 ...
Display device, 7 ... Waveform interface, 8 ... External storage device, 9 ... Communication interface, 1D ... Communication bus, X ... Communication network

Claims (11)

[Claims] 1. A step of supplying an original waveform relating to a sound containing a non-integer harmonic component, and a fundamental harmonic component which is a combination of at least a fundamental wave and one or more harmonics of the supplied original waveform, A step of classifying into a higher harmonic component composed of a combination of other harmonics, a step of generating compressed data for the classified basic harmonic component, and a step of generating compressed data for the classified upper harmonic component; Waveform compression method comprising. 2. A step of selecting either a harmonic to be combined with a fundamental wave or a harmonic not to be combined with a fundamental wave, wherein the supplied original waveform is at least a fundamental harmonic component based on the selection of the harmonic wave. 2. The waveform compression method according to claim 1, further comprising: 3. The waveform compression method according to claim 1, wherein the compressed data of the basic overtone component or the upper overtone component is to decompose the basic overtone component or the upper overtone component into a plurality of vectors. 4. The waveform compression method according to claim 3, wherein the plurality of vectors include any one of a waveform vector, a pitch vector, and an amplitude vector. 5. The compressed data of the basic overtone component is composed of a plurality of section compressed data obtained by dividing the basic overtone component into a plurality of sections on a time axis and compressing the basic overtone component of each section. The waveform compression method according to claim 1. 6. The compressed data of the upper harmonic component is composed of a plurality of section compressed data obtained by dividing the upper harmonic component into a plurality of sections on a time axis and compressing the upper harmonic component of each section. The waveform compression method according to claim 1. 7. The waveform compression method according to claim 5, wherein one of the plurality of section compression data corresponds to an attack part. 8. The waveform compression method according to claim 5, wherein at least one of the plurality of section compression data corresponds to a loop portion. 9. Compressed data for a fundamental overtone component consisting of a combination of a fundamental wave and one or more harmonics is obtained, and waveform data of the fundamental overtone component is obtained based on the obtained compressed data for the fundamental overtone component. Obtaining the compressed data for the upper harmonic component composed of the harmonics other than the harmonics of the fundamental harmonic component and generating the waveform data of the upper harmonic component based on the acquired compressed data for the upper harmonic component. Waveform generation including a step of generating, and a step of synthesizing the generated fundamental harmonic component waveform data and the generated upper harmonic component waveform data to generate a musical tone waveform relating to a sound including a non-integer harmonic component. Method. 10. A procedure of supplying an original waveform relating to a sound containing a non-integer overtone component to a computer, and a fundamental overtone consisting of a combination of at least a fundamental wave and one or more harmonics of the supplied original waveform. Component and a procedure of classifying into a higher harmonic component composed of a combination of other harmonics, a procedure of generating compressed data for the classified fundamental harmonic component, and generating compressed data for the classified higher harmonic component. A program that causes you to perform steps and 11. A computer obtains compressed data for a fundamental overtone component consisting of a combination of a fundamental wave and one or more harmonics, and based on the obtained compressed data for the fundamental overtone component, The procedure for generating waveform data and the compressed data for the upper harmonic component, which is composed of harmonics other than the harmonics of the fundamental harmonic component, is obtained, and the compressed data for the upper harmonic component is obtained based on the obtained compressed data for the upper harmonic component. Executes a procedure of generating waveform data and a procedure of synthesizing the generated waveform data of the fundamental overtone component and the generated waveform data of the upper overtone component to generate a musical tone waveform regarding a sound including a non-integer overtone component. A program to let you.