JPH10124065A - Musical sound waveform forming method and musical sound generating method for electronic musical instrument, and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a musical sound waveform forming method and a musical sound generating method and their device which can reproduce even a sound having fluctuations due to a frequency difference and an inharmonic sound at the time of additive synthesis. SOLUTION: A natural musical sound is inputted as a source waveform, a desired repetition degree (i) of analysis is inputted S1, and an analyzing means performs FFT for the input waveform to obtain frequency and amplitude information of respective harmonics S2. On the basis of the frequency and amplitude information, sin synthesis S3 is performed and synthesized waveform data are outputted to a storage means S4. Then the input waveform and the maximum harmonic of the synthesized waveform are made uniform in frequency and amplitude S5, the frequency and amplitude information is stored S6, and a difference waveform acquiring means subtracts the synthesized waveform after the process S5 from the input waveform to obtain a difference waveform S7. When the frequency of the said process does not reach the repetition degree (i) of analysis inputted at S1, a control means repeats the said process as many times as the degree (i) S8 to S10→S2 to S10 while regarding the difference waveform as an input waveform to obtain synthesized waveform data and the frequency and amplitude information of the waveform. Further, when the frequency of the process reaches the degree (i), the process is finished S11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a musical sound waveform in an electronic musical instrument, a method for generating a musical sound, and a method for generating the musical sound, by analyzing and resynthesizing natural musical sounds.

[0002]

2. Description of the Related Art Generally, FF is used as a method for analyzing natural sounds.
As a method of re-synthesizing the T method, there is a sin synthesizing method (a method of obtaining one waveform by superimposing sin waves having an appropriate frequency and an appropriate amplitude). In this sin synthesis method, the frequency of each overtone is generally set to an integral multiple of the frequency of the fundamental tone, and the length of the re-synthesized waveform is set to the wavelength of one cycle of the fundamental tone, thereby saving the waveform memory.

[0003]

Since the waveform re-synthesized by the above-described re-synthesis method has only integer overtones, such as a piano or a string, a plurality of sounds at a very close frequency are sounded simultaneously. In this case, the original tone of the sound was lost. Also, it was not possible to produce a sound that consisted of a harmonic component and a non-harmonic component produced when hitting metal, such as the sound of a bell. Therefore, when the re-synthesized waveform is repeatedly read and reproduced, the tone becomes monotonous and unnatural. On the other hand, as an improved method of such a resynthesis method, a method has been proposed in which a component insufficient in the resynthesized waveform is supplied as a PCM waveform (US Pat. No. 4,754,679, but a basic waveform is used instead of a resynthesized waveform). However, if the data has the waveform data in the PCM format, the memory cannot be saved and the problem has not been solved.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and has been developed for an electronic musical instrument capable of reproducing even a sound having fluctuation due to a frequency difference and a sound without harmoniousness when added and synthesized. It is an object of the present invention to provide a method of creating a musical sound waveform, a method of generating a musical sound, and these devices.

[0005]

According to the present invention, there is provided a musical sound waveform generating method for an electronic musical instrument, comprising the steps of:
Then, frequency and amplitude information of each harmonic is obtained, and sin synthesis is performed based on the frequency and amplitude information, and the frequency and amplitude of the maximum harmonic of the input waveform and the composite waveform are matched, and then subtracted from the input waveform,
In addition to obtaining the difference waveform,
The above-described processing is repeated by using the difference waveform as an input waveform to obtain the synthesized waveform data and frequency / amplitude information of the waveform.

A second aspect of the present invention relates to a method of generating a musical tone based on the synthesized waveform data created by the above method and the frequency / amplitude information of the waveform. On the basis of the frequency / amplitude information, the amplitude and frequency of the overtone at the maximum level are made equal to the input waveform, and are added and synthesized to generate a musical tone.

A third aspect of the present invention relates to the configuration of the apparatus according to the first aspect of the present invention, wherein the analyzing means obtains frequency / amplitude information of each overtone by FFT of an input waveform, and analyzes the frequency / amplitude information based on the frequency / amplitude information. A waveform synthesizing means for sin-synthesizing, a frequency waveform and an amplitude of the highest harmonic of the input waveform and the synthesized waveform, and subtracting the input waveform to obtain a differential waveform. It is characterized by comprising control means for repeating the above-described processing by using the difference waveform as an input waveform for an arbitrary analysis and synthesis order, and storage means for storing the synthesized waveform data and frequency / amplitude information of the waveform. .

[0008] In addition, the configuration of claim 4 is a configuration of an apparatus for implementing a method for generating a musical tone based on synthesized waveform data obtained by implementing the method of claim 1 and frequency / amplitude information of the waveform. In relation to the above, the input waveform is subjected to FFT to obtain frequency / amplitude information of each overtone, and sin synthesis is performed based on the frequency / amplitude information, and the frequency and amplitude of the maximum harmonic of the input waveform and the synthesized waveform are matched, and By subtracting from the waveform, a difference waveform is obtained, and the combined waveform data and frequency / amplitude information of the waveform obtained by repeating the above processing using the difference waveform as an input waveform for an arbitrary analysis / synthesis order are obtained. Storage means for storing, waveform reading means for reading out synthesized waveform data based on frequency information of each synthesized waveform stored in the storage means, and the synthesis read out based on amplitude information also stored in the storage means Waveform Envelope adding means for adding an envelope to the data, adding and synthesizing means for adding and synthesizing these musical tone waveforms having the envelope added thereto, and sound generating means for generating a musical tone based on the musical tone waveform obtained by the additive synthesis. It is characterized by.

[0009]

According to the configuration described in detail above, by repeating the difference of the synthesized waveform from the input waveform (in the case of repetition, the difference waveform becomes the input waveform), all of the plurality of resynthesized waveforms have different frequency components. (It becomes possible to take out components other than the harmonic components of the fundamental tone). Therefore, even if each resynthesized waveform has only an integer overtone, it is possible to obtain a sound having fluctuation due to a frequency difference or a sound with no harmony when added and synthesized.

[0010]

Embodiments of the present invention will be described below. FIG. 1 is a flowchart showing a procedure of extracting each synthesized waveform data and frequency / amplitude information of the waveform, which are created by the method of claim 1 and stored in the storage means of the musical tone generating apparatus, and FIG. FIG. 4 is a block diagram showing a configuration of an embodiment of a musical sound generating device in an electronic musical instrument according to claim 4.

First, as a musical sound waveform forming apparatus for carrying out the invention of claim 1, an analyzing means for performing FFT of an input waveform, a waveform synthesizing means for performing sin synthesis based on the analysis result, an input waveform and a synthesized waveform A difference waveform obtaining means for obtaining a difference waveform from the control signal, a control means comprising a CPU for instructing the above means to repeat the above processing by using the difference waveform as an input waveform for an arbitrary analysis / synthesis order i; RAM or R for storing synthesized waveform data and frequency / amplitude information of the waveform
It must have at least a storage means such as an internal storage device such as OM or an external storage device such as FD or HD.

Then, as shown in FIG. 1, a natural musical tone such as a piano is input as an original waveform to the above-mentioned device, and a desired analysis repetition order i is further input to the same device (S
1). In the apparatus, the input waveform is subjected to FFT by the analyzing means to obtain frequency / amplitude information of each harmonic (S2). Based on the frequency / amplitude information, the waveform synthesizing unit performs sin synthesis (S3), and outputs the synthesized waveform data to the storage unit (S4). Next, the frequency and amplitude of the maximum harmonic of the input waveform and the synthesized waveform are made equal (S5), and the frequency / amplitude information is stored in the storage means (S6). By the difference waveform acquisition means,
Subtract the synthesized waveform after the processing of S5 from the input waveform,
A difference waveform is obtained (S7). If the number of processes performed so far has not reached the analysis repetition order i input in S1, the control unit repeats the above process by using the difference waveform as the input waveform by the order i (S8).
To S10 → S2 to S10), the synthesized waveform data and frequency / amplitude information of the waveform are obtained. On the other hand, if the number of processes has reached the order i, the process is terminated (S1).
1).

As shown in FIG. 2, an electronic musical instrument having the configuration of the musical tone generating apparatus according to the present invention has a bus 100 used in the electronic musical instrument and a control signal / address in the electronic musical instrument through the bus 100. As a configuration for exchanging signals and data signals, a central processing unit CPU 101 that performs overall control and arithmetic processing, and a command /
A RAM 102 for temporarily storing data and the like and exchanging these commands and data with the CPU 101;
A program ROM 10 having a program memory 103a for storing a program to be executed by the CPU 101, a timbre data memory 103b for storing amplitude information extracted from the storage means, and a frequency table memory 103c for storing frequency information similarly extracted from the storage means.
3, a keyboard unit 104 with a touch sensor 104a for generating key information when a player presses a key, and a PCM for each synthesized waveform data extracted from the storage means.
A waveform ROM 105 stored as waveform data;
A digitally controlled oscillator DCO 106 having a polyphonic configuration of the order i, an envelope generator 107 and a multiplier 108 for adding an envelope to each tone generated from them, and adding and outputting each tone with an envelope. An adder 109, a D / A converter 110 for converting the tone signal from digital to analog, and a sound system 111 including an amplifier for amplifying the analog signal and an external output device including speakers and headphones for generating a tone are connected. Have been.
The CPU 101 includes a panel 112a and a pedal 112 which detect and generate information generated by a player's operation for selecting a tone color and sound (effect).
b and a MIDI interface 113 provided for exchanging MIDI signals with an external device.

According to the fourth aspect of the present invention, the timbre data memory 103b and the frequency table memory 1 serve as storage means for storing the frequency / amplitude information of the waveform.
The CPU 101 and each DCO 106 correspond to waveform reading means for reading out the synthesized waveform data from the waveform ROM 105 based on the frequency information of the frequency table memory 103, and the timbre data memory 103b
The CPU 101, the envelope generator 107, and the multipliers 108 also correspond as envelope adding means for adding an envelope to the waveform signal read out from the DCO 106 based on the amplitude information of The adder 109 corresponds to an adding / synthesizing means for adding and synthesizing these musical sound waveforms, and the D / A converter 110 and the sound system 111 serve as sound generating means for generating a musical tone based on the musical sound waveform obtained by the additive synthesizing. Would be equivalent.

In the configuration of the electronic musical instrument described above, when the player presses the keyboard 104, the PCM waveform data stored in the waveform ROM 105 corresponding to the key number is assigned to each DCO 106. The key number of the depressed key and the frequency number to be read by each DCO 106 from the frequency table memory 103 are stored in the CPU.
101 computes and passes them to each DCO 106. Also, amplitude information corresponding to the key number is read from the tone data memory 103b, and the envelope generator 107
The information is sent to As described above, each DCO 10
The envelope signal is enveloped by the envelope generator 107 and each of the multipliers 108 on the waveform signal read from 6, and these are added and synthesized by the adder 109. After that, the digital signal is converted into an analog signal by the D / A converter 110, and the sound is output from the sound system 111.

In the above configuration, the difference between the synthesized waveforms is repeated from the input waveform (in the case of repetition, the difference waveform becomes the input waveform), so that a plurality of resynthesized waveforms having different frequency components can be obtained. (It is also possible to take out components other than the harmonic components of the fundamental tone). Therefore, even if each resynthesized waveform resynthesized by the electronic musical instrument has only an integer harmonic, when added and synthesized, the resynthesized waveform may sound like a piano sound, such as a piano sound, or a bell sound. Even non-harmonic sounds can be generated in a state closer to the original waveform. Also, since the resynthesized waveform is only for a few cycles of the fundamental tone, even if the number (order) of the waveforms of the electronic musical instrument is considerably increased, much less memory than a PCM waveform having components less than the resynthesized waveform. Saves space.

In the above arrangement, the synthesized waveform data is stored in the storage means and read out to the reading means when a musical tone is generated. However, the frequency / amplitude information necessary for the synthesis is stored in the storage means to generate the musical sound or Sine synthesis may be performed by the waveform synthesizing means at the time of tone selection (in the case of musical tone generation, calculation processing necessary for waveform synthesis may reduce the number of simultaneous sounds, increase the time from sounding instruction to sounding start, etc.). Problems will arise).

Further, in the above configuration, the synthesized waveform data and its frequency / amplitude information separately created by the musical tone waveform creating method of the first aspect are preset in a ROM set in the electronic musical instrument. It is needless to say that the present invention can also be applied to a configuration in which a natural musical tone captured on the spot is stored in a RAM or other external storage device and a musical tone is generated using the natural musical tone.

[0019]

According to the configuration of the present invention described in detail above, by repeating the difference of the composite waveform from the input waveform, a plurality of recombined waveforms having different frequency components can be obtained. As a result, it is possible to take out components other than the overtone components of the fundamental tone, and even if each resynthesized waveform resynthesized by the electronic musical instrument has only integer overtones, when added and synthesized, the frequency resembles that of a piano sound. Even a non-harmonic sound such as a sound having a fluctuation due to a difference or a bell sound can be generated in a state closer to the original waveform. Also, since the resynthesized waveform is only for a few cycles of the fundamental tone, even if the number (order) of the waveforms of the electronic musical instrument is considerably increased, the memory capacity is far more than that having the component less than the resynthesized waveform as the PCM waveform. Savings.

[Brief description of the drawings]

FIG. 1 is a flowchart showing a procedure for extracting synthetic waveform data and frequency / amplitude information of the waveform.

FIG. 2 is a block diagram showing a configuration of an embodiment of a musical sound generator in an electronic musical instrument.

[Explanation of symbols]

 100 Bus 101 CPU 102 RAM 103 Program ROM 103a Program memory 103b Tone data memory 103c Frequency table memory 104 Keyboard unit 104a Touch sensor 105 Waveform ROM 106 DCO 107 Envelope generator 108 Multiplier 109 Adder 110 D / A converter 111 Sound system 112a Panel 112b Pedal 113 MIDI interface

Claims (4)

[Claims] 1. An FFT of an input waveform and the frequency of each harmonic
Amplitude information is obtained, sin-synthesizing is performed based on the frequency / amplitude information, and the frequency and amplitude of the maximum harmonic of the input waveform and the synthesized waveform are matched, then subtracted from the input waveform to obtain a difference waveform, and an arbitrary analysis is performed. A method for creating a musical tone waveform in an electronic musical instrument, characterized in that the above-described processing is repeated by using the difference waveform as an input waveform for the synthesis order, thereby obtaining the synthesized waveform data and frequency / amplitude information of the waveform. 2. An FFT of an input waveform is performed to calculate the frequency of each harmonic.
Amplitude information is obtained, sin-synthesizing is performed based on the frequency / amplitude information, and the frequency and amplitude of the maximum harmonic of the input waveform and the synthesized waveform are matched, then subtracted from the input waveform to obtain a difference waveform, and an arbitrary analysis is performed. The above-described processing is repeated by using the difference waveform as an input waveform for the synthesis order, and based on each synthesized waveform data obtained thereby and the frequency / amplitude information of the waveform,
A musical tone generating method for an electronic musical instrument, characterized in that the amplitude and frequency of the harmonic of the maximum level are made equal to the input waveform, added and synthesized, and a musical tone is generated. 3. An FFT of an input waveform is performed to calculate the frequency of each harmonic.
Analysis means for obtaining amplitude information; waveform synthesizing means for sin-synthesizing based on the frequency / amplitude information; and adjusting the frequency and amplitude of the maximum overtone of the input waveform and the synthesized waveform, and then subtracting the difference waveform from the input waveform to obtain a difference waveform. A difference waveform obtaining means to obtain, a control means for instructing each of the above means to repeat the above processing by using the difference waveform as an input waveform for an arbitrary analysis / synthesis order, and a frequency / frequency of the synthesized waveform data and the waveform. A musical tone waveform creating apparatus for an electronic musical instrument, comprising: storage means for storing amplitude information. 4. An FFT of an input waveform and the frequency of each harmonic
Amplitude information is obtained, sin-synthesizing is performed based on the frequency / amplitude information, and the frequency and amplitude of the maximum harmonic of the input waveform and the synthesized waveform are matched, then subtracted from the input waveform to obtain a difference waveform, and an arbitrary analysis is performed. Storage means for storing the synthesized waveform data and frequency / amplitude information of the waveform obtained by repeating the above processing by using the difference waveform as the input waveform for the synthesis order, and each of the storage means stored in the storage means; Waveform reading means for reading synthesized waveform data based on frequency information of the synthesized waveform;
An envelope adding means for adding an envelope to the synthesized waveform data read out based on the amplitude information also stored in the storage means; an adding and synthesizing means for adding and synthesizing these musical tone waveforms with the envelope added; And a sound generating means for generating a musical tone based on the musical tone waveform obtained by the electronic musical instrument.