JP4046589B2 - Music generator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a musical sound generator, and more particularly to a musical sound generator capable of generating not only a higher harmonic component but also a harmonic component one octave below.
[0002]
[Prior art]
In the conventional musical sound generator, when the waveform is a rectangular wave with respect to one cycle of waveform data, the harmonic component is changed by changing the duty ratio. As for the waveform data, the harmonic component is changed by changing the reading speed (phase modulation).
[0003]
[Patent Document 1]
JP-A-8-44365.
[0004]
[Problems to be solved by the invention]
However, in both cases, it is not possible to change the component below the fundamental frequency only by changing the frequency component above the fundamental frequency. Therefore, when a component lower than one octave is required, there is a problem that a new waveform data of that cycle must be generated and mixed.
[0005]
The present invention has been made to solve the above-described problems, and an object thereof is to provide a musical sound generating apparatus capable of generating not only a high-order harmonic component but also a harmonic component one octave lower. .
[0006]
[Means for Solving the Problems]
In order to achieve this object, a musical tone generator according to claim 1 comprises a waveform data storage means for storing waveform data, and a musical sound data generator for generating musical sound data based on the waveform data stored in the waveform data storage means. and means, and a tone output means for outputting the music data generated by the tone data generating means as a tone, further while the total period of the plurality of waveform data at a constant, the period of each waveform data includes a ratio setting means for setting a percentage of the total cycle, the musical sound data generating means, by connecting by modifying the one period of the waveform data of the plurality according to the ratio set by the ratio setting means The musical tone data having the total cycle as a cycle is generated.
[0007]
According to the musical tone generating apparatus of the first aspect, first, the ratio setting means sets the ratio of the period of each waveform data to the total period while keeping the total period of the plurality of waveform data constant . Then, according to the set ratio, the musical sound data generating means, by connecting by modifying the one period of each of the plurality of waveform data, music data having a period of total cycle is generated. The generated tone data is output as a tone by the tone output means.
[0008]
The musical tone generator according to claim 2 is the musical tone generator according to claim 1, wherein the waveform data storage means stores a plurality of different waveform data and a plurality of musical tone data having the total period as a cycle. The waveform data is characterized by being composed of at least two or more different waveform data.
[0009]
【The invention's effect】
According to the musical sound generating device of claim 1, while setting the total period of the plurality of waveform data to be constant , the ratio of the period of each waveform data within the total period is set, and according to the set ratio Since the musical sound data having the total period as a period is generated by deforming and concatenating one period of each of the plurality of waveform data, only the higher-order harmonic components are changed by changing the ratio of the period of the waveform data. In addition, it is possible to generate a harmonic component under one octave. Therefore, there is an effect that the harmonic component can be variously changed without performing an extra waveform generation process.
[0010]
According to the musical sound generating device according to claim 2, in addition to the effect produced by the musical sound generating device according to claim 1, the plurality of waveform data constituting the musical sound data having a total period as a cycle are at least two or more types. Since it is composed of different waveform data, there is an effect that not only overtone components but also various changes in timbre can be performed.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a block diagram showing an electrical configuration of a musical tone generator 1 according to an embodiment of the present invention. The musical tone generator 1 of the present embodiment , for one set of waveform data in which two waves are concatenated, one first half wave (first half waveform 39 in FIG. 3) and one second half wave (second half waveform 40 in FIG. 3) By changing the duty ratio, it is possible to freely change overtone components, particularly ½ overtones.
[0012]
The musical sound generating device 1 includes a CPU 2 that is an arithmetic unit, a ROM 3 that stores various control programs and fixed value data executed by the CPU 2, and various data and the like in executing the control program stored in the ROM 3. And a RAM 4 which is a memory for temporarily storing. The CPU 2, ROM 3 and RAM 4 are connected to each other by a bus line 5 constituted by an address bus and a data bus. This bus line 5 is connected to various I / O devices via an input / output port 6. Yes.
[0013]
The input / output port 6 has an operation panel 9 provided with a plurality of operating element groups 7 and a liquid crystal display device (hereinafter referred to as “LCD”) 8, and a plurality of instructions for instructing generation start and stop of musical sounds. A keyboard 10 having a key and a sound source (hereinafter referred to as “DSP (Digital Signal Processor)”) 11 that generates a musical sound are connected to each other. The DSP 11 is connected to a D / A converter 12 that converts a digital signal of a musical tone output from the DSP 11 into an analog signal. The D / A converter 12 is connected to the analog signal converted by the D / A converter 12. The amplifier 13 is connected to a speaker 14 that outputs the amplified analog signal as a sound.
[0014]
FIG. 2 is a front view of the operation panel 9 of the musical sound generator 1. The operation panel 9 is provided with ten selection switches 71 to 80 and two rotary knobs 81 and 82 that constitute the operator group 7, and the LCD 8. The selection switches 71 to 80 are composed of five selection switches 71 to 75 for setting the first half waveform 39 and five selection switches 76 to 80 for setting the second half waveform 40 of the two waveform data. Yes. By operating these selection switches 71 to 80, a sawtooth wave (see FIG. 4A), a rectangular wave (see FIG. 4B), and a sine wave (SIN wave) (see FIG. 4C). ), A triangular wave (see FIG. 4D), and a ramp wave (see FIG. 4E) can be individually set as the first half waveform 39 and the second half waveform 40, respectively.
[0015]
The rotary knobs 81 and 82 include a duty knob 81 and a tone knob 82. The duty knob 81 is a knob that connects the first half waveform 39 and the second half waveform 40 and sets the period ratio (hereinafter referred to as “Duty value”) of the first half waveform 39 in the total cycle of the two connected waves. The period ratio (Duty value 37) of the first half waveform 39 can be set in the range of 5% to 95%. That is, as shown in FIG. 3, it is a knob for adjusting the ratio of the period B of the first half wave to the total period D of two waves. When the duty value 37 is set to 50% by the duty knob 81, the first half waveform 39 and the second half waveform 40 have the same period.
[0016]
The tone knob 82 is a knob for setting the ratio of the first half of each waveform (hereinafter referred to as “Tone value”) for each of the first half waveform 39 and the second half waveform 40, and the ratio of the first half (Tone value 38). It can be set in the range of 5% to 95%. That is, as shown in FIG. 3, for the first half waveform 39, the ratio of the first half portion A to the whole portion B, and for the second half waveform 40, the ratio of the first half portion (C-B) to the whole portion (D-B). It is a knob to set. Note that the tone knob 82 of the present embodiment sets the Tone value 38 of the first half waveform 39 and the second half waveform 40 to be the same, but this Tone value 38 can be set individually for the first half waveform 39 and the second half waveform 40, respectively. Anyway.
[0017]
On the LCD 8 provided on the operation panel 9, the operation states of the selection switches 71 to 80 and the rotary knobs 81 and 82 are displayed. In FIG. 2, as a result of the selection switches 75 and 79 being pressed, a slope wave is set as the first half waveform 39 and a triangle wave is set as the second half waveform 40, and the duty knob 81 is at a 45% position (ie, the duty value is 45). %), The tone knob 82 is set to the 50% position (that is, the Tone value is 50%).
[0018]
FIG. 3 is a diagram showing the waveform of the waveform data composed of two waves, and corresponds to the setting state of the operation panel 9 of FIG. That is, in FIG. 3, a slope wave (see FIG. 4 (e)) is selected as the first half waveform 39, and a triangular wave (see FIG. 4 (d)) is selected as the second half waveform 40, and the duty value is 45%. A state in which the Tone value is set to 50% is illustrated.
[0019]
Here, the variables A to D will be described. The variable D is a length corresponding to two periods (a unit is a sampling period) including the first half waveform 39 and the second half waveform 40, and is represented by “D = 44100 / tone generation frequency / 2”. “44100” is the sampling frequency of the musical sound generated by the DSP 11, and is the reciprocal of the sampling period. The waveform generation process is executed every 1/444100 seconds. The variable B is the length of the first half wave (first half waveform 39) and is represented by “B = D × Duty value”. The variable A is the length of the first half of the first half wave (first half waveform 39), and is represented by “A = B × Tone value”. Furthermore, the variable C is the length of the first half of the latter half 1 wave (the latter half waveform 40), and is represented by “C = B + (D−B) × Tone value”.
[0020]
Also, in the calculation formulas f (t) and g (t) in FIG. 3, 0, A, and B are substituted for α, β, and γ in the calculation formulas of the waveforms shown in FIGS. In the same way, the calculation formulas h (t) and i (t) are α, β of the calculation formulas of the waveforms shown in FIGS. , Γ is substituted for B, C, and D, respectively, and the calculation formula of the latter half waveform 40 is obtained. Assuming that the horizontal axis is t and the vertical axis is y, the calculation formula of the first half waveform 39 is represented by y = f (t) in the first half, y = g (t) in the second half, and the second half waveform 40. The first half is y = h (t) and the second half is y = i (t). Further, t is a sampling time, and is a value that increases by 1 / D for each sampling period. Here, when the sampling time t exceeds D, t = 0 is not set and t is obtained by subtracting D from t. This is because when t = D is not satisfied, the fraction is left without being deleted. 4A to 4E are stored in the ROM 3, read out in response to pressing of the selection switches 71 to 80, and output to the DSP 11.
[0021]
FIG. 5 is a functional block diagram of the DSP 11. The DSP 11 mainly includes a waveform generation control unit 21, a waveform generation unit 22, a volume control unit 23, and a waveform generation formula storage unit 24. The waveform generation control unit 21 stores a tone generation frequency 35 corresponding to each key provided on the keyboard 10 and a volume 36 corresponding to the key pressing speed 33. The waveform generator 22 receives the duty value 37 set by the duty knob 81 of the operation panel 9 and the tone value 38 set by the tone knob 82 from the CPU 2 via the input / output port 6, respectively. Entered. Similarly, in the waveform generation formula storage unit 24, the generation formulas (calculation formulas) of the first half waveform 39 and the second half waveform 80 selected by the selection switches 71 to 80 are read from the ROM 3 by the CPU 2 and input / output port 6 is set. Respectively. For the first half waveform 39, the first half is stored as the generation formula “y = f (t)”, the second half is stored as the generation formula “y = g (t)”, and the second half waveform 40 is stored in the first half. The part is stored as the generation formula “y = h (t)” and the latter half is stored as the generation formula “y = i (t)” in the waveform generation formula storage unit 24.
[0022]
Next, the operation of the DSP 11 will be described with reference to this functional block diagram. When any key of the keyboard 10 is pressed, the sound generation start instruction 31, the key number 32 of the pressed keyboard 10, and the key pressing speed 33 of the keyboard 10 are output from the CPU 2 to the waveform generation control unit 21, respectively. Is done. When receiving the sound generation start instruction 31, the waveform generation control unit 21 outputs a sound generation frequency 35 corresponding to the key number 32 of the pressed keyboard 10 to the waveform generation unit 22, and generates a sound at the sound generation frequency 35. The waveform generation unit 22 is called every sampling period (in the present embodiment, 1/44100 seconds) to execute the waveform generation process shown in FIG. In addition, the waveform generation control unit 21 instructs the volume control unit 23 to set the volume 36 corresponding to the key pressing speed 33 of the keyboard 10 together with the instruction to the waveform generation unit 22.
[0023]
When the waveform generation unit 22 receives an execution instruction of the waveform generation process together with the sound generation frequency 35 from the waveform generation control unit 21, the duty value 37, the Tone value 38, and the first half waveform 39 or the second half stored in the waveform generation formula storage unit 24. The waveform generation process is executed with reference to the calculation formula of the waveform 40, and the tone signal 41 at that timing is output to the volume control unit 23. The volume control unit 23 converts the musical sound signal 41 output from the waveform generation unit 22 into a volume 36 instructed by the waveform generation control unit 21, which is used as musical sound data 42, and a D / A converter at the next stage. 12 is output. Thereby, the output of the musical sound from the speaker 14 is started.
[0024]
On the other hand, when the key is released, the CPU 2 outputs a sound generation stop instruction 34 to the waveform generation control unit 21. When receiving the sound generation stop instruction 34, the waveform generation control unit 21 stops calling the waveform generation process in the waveform generation unit 22 and instructs the volume control unit 23 to set the volume “0”. Thereby, the output of the musical sound data 42 from the DSP 11 is stopped, and the musical sound output from the speaker 14 is ended.
[0025]
Next, with reference to FIG. 6, the waveform generation process executed by the waveform generator 22 of the DSP 11 will be described. FIG. 6 is a flowchart showing a waveform generation process executed every 1/444100 seconds. In this waveform generation process, based on the value of the sampling time t, the tone signal 41 at that time is calculated and the value of the sampling time t is updated.
[0026]
In the waveform generation process, first, each value of the variables D, B, A, and C is obtained from the above formula. That is, the variable D, which is the length of two cycles, is obtained by D = 44100 / (sound generation frequency / 2) (S1), and the variable B, which is the length of the first half waveform 39, is obtained by B = D × Duty value. (S2) The variable A, which is the length of the first half of the first half waveform 39, is obtained by A = B × Tone value (S3), and the variable C, which is the length of the first half of the second half waveform 40, is C = Obtained by B + (D−B) × Tone value (S4). Then, in order to calculate the musical sound signal 41 of the first half waveform 39, 0 is substituted for the variable α, the variable A is substituted for the variable β, and the variable B is substituted for the variable γ (S5).
[0027]
Next, if the sampling time t is t <variable A (S6: Yes), the waveform is the first half of the first half waveform 39, so that the sampling time t is calculated based on the calculation formula y = f (t). The musical tone signal 41 at is calculated (S7). If the sampling time t is variable A ≦ t <variable B (S6: No, S8: Yes), the waveform is the latter half of the first half waveform 39, and therefore, based on the calculation formula y = g (t). Then, the tone signal 41 at the sampling time t is calculated (S9).
[0028]
If the sampling time t is variable B ≦ t (S8: No), the variable B is set as the variable α, the variable C is set as the variable β, and the variable D is set as the variable γ in order to calculate the musical sound signal 41 of the latter half waveform 40. Each is substituted (S10). If the sampling time t is variable B ≦ t <variable C (S11: Yes), the waveform is the first half of the latter half waveform 40, and therefore the sampling is performed based on the calculation formula y = h (t). A musical sound signal 41 at time t is calculated (S12). If the sampling time t is variable C ≦ t (S11: No), the waveform is the latter half of the latter half waveform 40, and therefore, at the sampling time t based on the calculation formula y = i (t). A musical sound signal 41 is calculated (S13).
[0029]
After the music signal 41 is calculated, the sampling time t is updated. That is, 1 / D time is added to the sampling time t (S14), and if the added sampling time t is not the variable D ≦ t (S15: No), the first half waveform 39 and the second half waveform 40 are constituted. Since a series of waveforms are being output, the value of t updated in S14 is left as it is, and the waveform generation process is terminated. On the other hand, if the variable D ≦ t (S15: Yes), since the output of a series of waveforms composed of the first half waveform 39 and the second half waveform 40 has been completed, the variable is changed from the sampling time t to output such a new waveform. The time of D is subtracted to obtain a new sampling time t (S16), and this shape generation process is terminated. The musical sound signal 41 calculated by the waveform generation processing is immediately output to the volume control unit 23, converted into musical sound data 42 according to the volume 36 output from the waveform generation control unit 21, and output to the D / A converter 12. Then, after being amplified by the amplifier 13, it is output as a musical sound from the speaker 14.
[0030]
As described above, according to the musical sound generator 1 of the present embodiment, the duty value 37 is set within the total period D based on the total period D of the first half waveform 39 and the second half waveform 40 (constant). Then, the waveform data is transformed according to the duty value 37 to generate the musical sound signal 41 (and the musical sound data 42 according to the volume 36), so that only the higher harmonic components are obtained by changing the duty value 37. In addition, a harmonic component under one octave can be generated, and the harmonic component can be changed variously. In addition, the first half waveform 39 and the second half waveform 40 can be set as the same or different waveform data, and the ratio of the first half portion (Tone value 38) can be set for each of the first half waveform 39 and the second half waveform 40. Various timbre changes can be made by setting.
[0031]
Next, a second embodiment will be described with reference to FIG. Musical tone generating apparatus 1 of the first embodiment described above, as a set by concatenating the two waves and the waveform 40 late and early waveform 39, by changing the duty ratio (Duty value 37), harmonics, particularly 1 / Change overtones freely. On the other hand, the musical tone generator of the second embodiment is one in which the harmonic components can be freely changed by connecting three waves as one set. Hereinafter, the same parts as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.
[0032]
In the second embodiment, since the duty value 37 and the tone value 38 are one each, the ratio between the first half wave 51, 52 and the second half wave 53 is determined by the duty value 37, and the first half wave 51, 52 is determined. The ratio is 50% each. Further, the Tone value 38 defines the ratio of the first half portion for each of the three waves 51 to 53.
[0033]
Therefore, the variables A to F of the second embodiment will be described. The variable F is a length corresponding to three periods including the three waves 51 to 53 (the unit is a sampling period), and “F = 44100 / tone generation frequency”. / 3 ". As in the first embodiment, “44100” is the sampling frequency of the musical sound generated by the DSP 11 and is the reciprocal of the sampling period. The variable D is the total period of the first two waves 51 and 52 and is represented by “D = F × Duty value”. The variable B is the period of the first wave 51 and is represented by “B = D / 2”. The variable A is the length of the first half of the first wave 51 and is represented by “A = B × Tone value”. The variable C is the length of the first half of the second wave 52 and is represented by “C = B + (D−B) × Tone value”. Further, the variable E is the length of the first half portion of the third wave 53 and is expressed by “E = D + (FD) × Tone value”.
[0034]
Further, in the calculation formulas f (t) and g (t) in FIG. 7, 0, A, and B are substituted for α, β, and γ in the calculation formulas of the waveforms shown in FIGS. Similarly, the calculation formulas h (t) and i (t) are α, which are the calculation formulas of the waveforms shown in FIGS. 4 (a) to 4 (e). The formula for calculating the second wave 52 is obtained by substituting B, C, and D for β and γ, respectively. Furthermore, the calculation formulas j (t) and k (t) are obtained by substituting D, E, and F into α, β, and γ in the calculation formulas of the waveforms shown in FIGS. This is a formula for calculating the wave 53.
[0035]
Assuming that the horizontal axis is t and the vertical axis is y, the calculation formula of the first wave 51 is expressed by y = f (t) in the first half and y = g (t) in the second half. The calculation formula of the wave 52 is represented by y = h (t) in the first half and y = i (t) in the second half, and the calculation formula of the third wave 53 is y = j (t ), The latter half is represented by y = k (t). Further, t is a sampling time, and is a value that increases by 1 / F for each sampling period. Here, when the sampling time t exceeds F, t = 0 is not set and t is obtained by subtracting F from t. This is because when t = F is not satisfied, the fraction is not deleted.
[0036]
According to the musical sound generating apparatus of the second embodiment, the duty value 37 is set within the total period F on the basis of the total period F of the three waves 51 to 53 (constant), and the duty value 37 is set according to the duty value 37. Therefore, the waveform data is transformed to generate the musical tone signal 41 (and the musical tone data 42 according to the volume 36). Therefore, by changing the duty value 37, not only the higher-order harmonic component but also the harmonic component one octave lower. Can be generated, and the overtone component can be changed variously. In addition, the three waves 51 to 53 can be set as the same or different waveform data, and the ratio of the first half portion (Tone value 38) can be set for each of the three waves 51 to 53. Changes can be made.
[0037]
It should be noted that the duty value may be set to two or more, and the ratio of the three waves 51 to 53 may be set individually. Similarly, two or three or more Tone values may be set so that the ratio of the first half of the three waves 51 to 53 can be set individually.
[0038]
The present invention has been described based on the embodiments. However, the present invention is not limited to the above-described embodiments, and various improvements and modifications can be easily made without departing from the spirit of the present invention. It can be guessed.
[0039]
For example, in each of the embodiments described above, two or three waves are combined into one set, and the duty ratio (Duty value 37) is changed to freely change the harmonic component. The data may be set as one set and the duty ratio (Duty value 37) may be changed. In such a case, the Duty value and Tone value may be individually set for each waveform data.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an electrical configuration of a musical sound generator according to an embodiment of the present invention.
FIG. 2 is a front view of an operation panel of the musical sound generating device.
FIG. 3 is a diagram showing a waveform of one set of waveform data with two waves.
4A is a sawtooth wave, FIG. 4B is a rectangular wave, FIG. 4C is a sine wave (SIN wave), FIG. 4D is a triangular wave, and FIG. 4E is a slope wave. And a calculation formula thereof.
FIG. 5 is a functional block diagram of a DSP.
FIG. 6 is a flowchart showing a waveform generation process executed by a waveform generation unit of a DSP.
FIG. 7 is a diagram showing a waveform of a set of three waveform data output from the musical sound generator of the second embodiment.
[Explanation of symbols]
1 musical tone generator 3 ROM (waveform data storage means)
11 Sound source (DSP) (musical sound data generation means)
12 D / A converter (part of musical sound output means)
13 Amplifier (part of musical sound output means)
14 Speaker (part of musical sound output means)
21 Waveform generation control unit 22 Waveform generation unit 23 Volume control unit 24 Waveform generation formula storage unit 37 Duty value 38 Tone value 39 First half waveform 40 Second half waveform 81 Duty knob (ratio setting means)
82 Tone knob

Claims (2)

Waveform data storage means for storing waveform data, musical sound data generation means for generating musical sound data based on the waveform data stored in the waveform data storage means, and musical sound data generated by the musical sound data generation means as musical sounds In a musical sound generator having a musical sound output means for outputting,
While the total period of the plurality of waveform data to be constant, it includes a ratio setting means for setting the ratio of the total period of the cycle of the waveform data,
The musical tone data generating means generates musical tone data having the total period as a period by transforming and connecting one period of each of the plurality of waveform data according to the ratio set by the ratio setting means. A musical sound generator characterized by being a thing. The waveform data storage means stores a plurality of different waveform data, and the plurality of waveform data constituting the musical tone data having the total period as a cycle is composed of at least two types of different waveform data. The musical tone generator according to claim 1.

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