KR100693964B1 - Waveform generating device and method, musical sound synthesis apparatus, and computer-readable storage medium - Google Patents

Abstract

Generate waveforms with complex waveform shapes simply and richly controllable. At least two sample points are specified to change a waveform of a predetermined basic waveform, and in one cycle of change of phase information, the change of the phase information over the section between the specified at least two sample points overlaps at least at least. The progress of the phase information is controlled to be repeated once. Alternatively, the progress of the phase information is controlled so that at least one sample point is specified and the sample data of the sample point is maintained without changing for a predetermined time. This makes it possible to easily generate a waveform in which the basic waveform is deformed by repeating the waveform portion of the specified section or by holding the specific sample data for an arbitrary time. On the other hand, the frequency change of the generated waveform accompanying the waveform change (desired pitch) by changing the frequency information and adjusting the rate of change of the phase information according to the specified interval of at least two sample points or according to the stop time. Deviation from) can be eliminated.

Phase information, sample point, operator, frequency information, read address signal

Description

WAVEFORM GENERATING DEVICE AND METHOD, MUSICAL SOUND SYNTHESIS APPARATUS, AND COMPUTER-READABLE STORAGE MEDIUM}

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a block diagram showing an embodiment of the entire configuration of a frequency modulation arithmetic sound synthesis apparatus to which a waveform generator according to the present invention is applied.

2 is a block diagram showing one embodiment of the basic configuration of an operator (waveform generator);

3 is a circuit diagram showing a specific example of a phase generator according to the first embodiment.

4 is a diagram showing an AG output waveform obtained by accumulating a pitch frequency number output from a phase generator according to the first embodiment over time, (a) when there is no repeat reading, and (b) when repeat reading is not performed. The figure which shows the case.

Fig. 5 is a circuit diagram showing a concrete embodiment of the address generator according to the first embodiment.

Fig. 6 is a diagram showing an AG output waveform output from the address generator according to the first embodiment.

FIG. 7 is a diagram showing an example of waveforms generated when a sine wave is read from a wave table based on the AG output waveform shown in FIG. 6; FIG.

8 is a circuit diagram showing a concrete embodiment of the phase generator according to the second embodiment.

Fig. 9 is a diagram showing an AG output waveform obtained by accumulating the pitch frequency number outputted from the phase generator according to the second embodiment over time, and (a) shows that there is no progress stop of the waveform read address of the basic waveform. (B) is a diagram showing a case where there is a stop of the progress of the waveform read address of the basic waveform.

10 is a circuit diagram showing a concrete embodiment of the address generator according to the second embodiment.

Fig. 11 is a diagram showing an AG output waveform output from the address generator according to the second embodiment.

FIG. 12 is a diagram showing an example of waveforms generated when a sine wave is read from a wave table based on the AG output waveform shown in FIG. 11; FIG.

<Explanation of symbols for the main parts of the drawings>

OM: Operator

OC: Operator (carrier)

S1 (S2, S3): Selector

PG: Phase Generator

AG: Address Generator

EG: Envelope Generator

WT: Wave Table

K1 (K2, K3): Adder

J1 (J2): Multiplier

B: shifter

E: correction factor calculator

H1 (H2): comparison circuit

N1 (N2): OR circuit

O1 (O2): EXOR Circuit

CN: Counter

Q: Decoder

D (D1, D2): delay circuit

G: gate circuit

P: Inverter

M: Subtractor

[Patent Document 1] Japanese Patent Application Laid-Open No. 6-44193

The present invention relates to a waveform generating apparatus and method suitable for use in generating a sound signal. In particular, the present invention relates to a waveform generating apparatus and method for modifying a basic waveform so that a waveform having a complex waveform shape can be generated simply and controlably.

Background Art Conventionally, a device for generating a sound signal, for example, a so-called FM method sound synthesizer (also called an FM sound source) for synthesizing a sound signal having a desired harmonic configuration by a frequency modulation operation (FM operation) in the audible frequency domain. This is known. As is known in the prior art, in the FM system, a sound wave synthesizer basically generates a carrier signal and a modulated wave signal, and modulates the carrier signal by a modulated wave signal, thereby generating a tone signal having a desired spectrum configuration. Generally, such a FM system for sound synthesis | combination is provided with the waveform generator called an operator which can generate | occur | produce basic waveforms, such as a sine wave. In this operator (waveform generator), a predetermined basic waveform (sample data) consisting of a plurality of sample points stored in advance is read or generated from a waveform table in accordance with phase information which is changed to a desired frequency corresponding to the pitch of a musical sound. The generated basic waveform is used as a carrier signal, a modulated wave signal, or the like for frequency modulation calculation (FM calculation).

By the way, in the above-described FM system for synthesizing a sound, in order to generate a sound signal that realizes various tones, the waveforms of the carrier signal and the modulated wave signal may be complicated. Thus, controlling reading of the basic waveform from the waveform table has been conventionally performed. As an example of such a thing, there is a sound synthesis apparatus described in Patent Document 1. In the sound synthesis apparatus described in Patent Document 1, a sine wave (corresponding to a basic waveform) previously stored from a sine wave table (corresponding to a waveform table) while changing a phase value in a predetermined phase section or ignoring lower bits. After the waveform data of the sine wave is changed by reading the sample data, the complex waveform signal can be generated by using the waveform after the waveform shape change for frequency modulation calculation.

However, as the reading control of the basic waveform, as described above, by simply reading the sine wave from the sine wave table while performing control such as simply shifting the phase value in the predetermined phase section or ignoring the lower bit, It is difficult to change the waveform shape significantly. Therefore, there has been a problem that it is very difficult to generate a more complex musical tone signal that realizes various tones using the waveform thus generated.

SUMMARY OF THE INVENTION The present invention has been made in view of the foregoing, and a waveform generating apparatus and method for generating a waveform having a complex waveform shape with a large change compared to a basic waveform in a simple and controllable manner, and a computer reading related thereto. It is intended to provide a possible storage medium.

A waveform generating device according to a first aspect of the present invention includes basic waveform generating means for generating sample data of a sample point according to input phase information among sample data of a predetermined basic waveform consisting of a plurality of sample points, and the basic element. Means for specifying at least two sample points for changing the waveform of the waveform, means for obtaining frequency information for setting the frequency of the waveform to be generated, and the acquired frequency information for the specified at least two sample points. Change means for changing in accordance with an interval of, phase information generating means for generating phase information changed at a rate corresponding to the frequency information based on the changed frequency information, and the phase generated by the phase information generating means. In one cycle of change of information, the change of the phase information over the section between the specified at least two sample points is Control means for controlling the progression of the phase information generated by the phase information generating means so as to be repeated at least once in duplicate, the phase generated by the phase information generating means under control by the control means; By inputting the information into the basic waveform generating means, a waveform in which the basic waveform is deformed in accordance with the phase information whose progression in one cycle is controlled is characterized in that it is generated from the basic waveform generating means.

According to the present invention, at least two sample points are specified to change a waveform of a predetermined basic waveform, and in one cycle of change of phase information, the change of the phase information over the section between the specified at least two sample points By controlling the progress of the phase information so that is repeated at least once, the waveform portion of the overlapping section is repeated, whereby a waveform modified from the basic waveform can be easily generated. On the other hand, since the frequency information for setting the frequency of the waveform to be generated is changed in accordance with the specified interval of at least two sample points, the phase information is changed at a rate corresponding to the changed frequency information. In connection with changing the shape of the waveform, the rate of change of the phase information is variably controlled, so that the change in frequency (period) of the generated waveform which may be caused by the control / manipulation of the phase advance pattern (from the desired pitch) Deviation) can be eliminated or adjusted arbitrarily.

For example, according to a parameter specifying at least two sample points, the phase information changing at a rate according to the frequency information is caused to be repeated in the positive and reverse directions between the specified at least two sample points. The frequency information used for the rate at which the phase information changes is changed by changing the frequency information for setting the frequency of the waveform to be generated according to the parameter specifying the at least two sample points. Then, by inputting the generated phase information to the basic waveform generating means for generating sample data of a predetermined basic waveform consisting of a plurality of sample points, a waveform in which the basic waveform is deformed in accordance with the change of the phase information is generated. When inputting phase information generated by repeating in a positive and reverse direction between at least two specified sample points to generate sample data of a predetermined basic waveform, inputting without changing the phase information occurs without the repetition. Compared to the pitch of the waveform generated by inputting the phase information to be generated, the pitch of the waveform generated by the minute of repetition is increased. Accordingly, frequency information is changed in accordance with the parameter specifying the at least two sample points, and sample data of a predetermined basic waveform is generated based on phase information that changes at a rate according to the changed frequency information. In this way, the user can generate a waveform having a complex waveform shape easily and controlably simply by specifying at least two sample points, without changing the desired pitch, or by arbitrarily adjusting the pitch. Will be.

Therefore, according to the present invention, since a waveform having a complex waveform shape with a large change compared to a basic waveform can be generated simply and with abundant controllability, various tones can be realized using the generated waveform, and a more complex musical sound can be generated. The effect is that the signal can be easily generated.

A waveform generating device according to a second aspect of the present invention includes basic waveform generating means for generating sample data of a sample point according to input phase information among sample data of a predetermined basic waveform consisting of a plurality of sample points, and the basic element. Means for generating a waveform change parameter for changing a waveform of the waveform, the waveform change parameter including a parameter specifying at least one sample point and a stop time parameter for setting a time for holding the specified sample point Means for acquiring frequency information for setting a frequency of a waveform to be generated, changing means for changing the acquired frequency information according to the stop time parameter, and the frequency information based on the changed frequency information. Phase information generating means for generating phase information changed at a corresponding rate; In one cycle of the change of the phase information generated by the generating means, to keep the value of the phase information corresponding to the specified at least one sample point without changing by the time set by the stop time parameter, And control means for controlling the progression of the phase information generated by the phase information generating means, wherein the phase information generated by the phase information generating means is controlled by the control means by the control means. By inputting, the waveform which deform | transformed the said fundamental waveform according to the said phase information by which progress in one cycle was controlled is characterized by making it generate | occur | produce from the said basic waveform generating means.

According to the present invention, to change a waveform of a predetermined basic waveform, a waveform change parameter is generated that includes a parameter specifying at least one sample point and a stop time parameter for setting a time for holding the specified sample point. Controlling the progress of the phase information so that, in one cycle of change of the phase information, the value of the phase information corresponding to the specified at least one sample point is maintained without changing by the time set by the stop time parameter. As a result, the sample data of the same sample point is kept overlapping for the set time, thereby making it possible to easily generate a waveform in which the basic waveform is deformed. On the other hand, since the frequency information for setting the frequency of the waveform to be generated is changed according to the stop time parameter and the phase information is changed at a rate corresponding to the changed frequency information, the shape of the generated waveform is changed. In relation to this, the rate of change of the phase information is variably controlled, thereby eliminating or arbitrarily eliminating the change (deviation from the desired pitch) of the frequency (period) of the generated waveform which may be caused by the control / manipulation of the phase advance pattern. I can adjust it.

For example, if the waveform is generated without changing the phase information, the period of the generated waveform becomes longer (the pitch is lowered) by the amount of time stopped to maintain the same sample point. Change the frequency information according to the stop time parameter (change to raise the rate of change of phase information), and based on the phase information changed to a rate (at a relatively high rate) according to the changed frequency information Read the sample data of the waveform. Thereby, the delay factor by keeping the same sample point by the specified stop time minute is compensated, and the waveform in which the basic waveform was deformed can be generated at a desired pitch. In this way, the phase information is controlled to pause (temporarily hold) any sample point of the basic waveform so that the waveform is generated, and the user only specifies the stop (hold) time and at least one sample point. By freely adjusting the pitch without changing the desired pitch, it is possible to generate a waveform having a complex waveform shape simply and richly in control.

According to the common concept of the present invention according to the first and second aspects described above, the following waveform generation device can be provided. That is, the waveform generator according to the present invention includes basic waveform generating means for generating sample data of a sample point according to input phase information among sample data of a predetermined basic waveform consisting of a plurality of sample points, and Means for specifying at least one sample point and specifying overlapping sections based on the specific sample point to change the waveform, means for obtaining frequency information for setting the frequency of the waveform to be generated; Changing means for changing the acquired frequency information according to the length of the specified overlapping section, phase information generating means for generating phase information changed at a rate corresponding to the frequency information based on the changed frequency information; At least one sample point specified in one cycle of the change of the phase information generated by the phase information generating means. And control means for controlling the progression of the phase information generated by the phase information generating means so that the change of the phase information is repeatedly repeated or maintained in the specified overlapping section based on the; By inputting the phase information generated by the phase information generating means to the basic waveform generating means under control by a control means, a waveform in which the basic waveform is deformed in accordance with the phase information whose progression in one cycle is controlled is Characterized in that it is generated from the basic waveform generating means.

Even in this case, according to the present invention, in order to change the waveform of a predetermined basic waveform, at least one sample point is specified, and an overlapping section based on the specific sample point is specified and In one cycle, modifying the fundamental waveform by controlling the progress of the phase information such that the change of the phase information is repeatedly repeated or maintained in the specified overlapping interval based on the specified at least one sample point. One waveform can be easily generated. On the other hand, the frequency information for setting the frequency of the waveform to be generated is changed according to the length of the specified overlapping section, and the phase information is changed at a rate corresponding to the changed frequency information. In connection with changing the shape, the rate of change of the phase information is variably controlled, so that the change in frequency (period) of the generated waveform which may be caused by the control / manipulation of the phase advance pattern (deviation from the desired pitch) Can be solved or adjusted arbitrarily.

The present invention can be configured and practiced as the invention of the apparatus, as well as the invention of the method. In addition, the present invention can be implemented in the form of a program of a processor such as a computer or a DSP, or can be implemented in the form of a storage medium storing such a program.

<Example>

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described in detail according to an accompanying drawing.

First, a sound synthesis apparatus of a frequency modulation operation type (hereinafter referred to as "FM method") to which the waveform generator according to the present invention is applied will be briefly described with reference to FIGS. 1 and 2. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a block diagram showing an embodiment of the overall configuration of a frequency synthesized sound synthesizer of a frequency modulation operation type (FM method) to which a waveform generator according to the present invention is applied. FIG. 2 is a block diagram showing an embodiment of the basic configuration of the operator shown in FIG. 1 (corresponding to one embodiment of the waveform generator, that is, the "waveform generator" according to the present invention). However, as known in the art, in the FM system, a sound generator can be provided with one operator, which is a computation unit, which is hard as a waveform generator, and is shown in FIG. 1 by time-dividing this operator into two time slots. It is supposed to function as two operators (modulator OM or carrier OC described later). Therefore, in FIG. 2, only one representative operator is shown, and an operator (modulator OM or carrier OC) is briefly described using this. Hereinafter, an operator (waveform generator) that functions as a modulated wave generator is referred to as "modulator OM", and an operator (waveform generator) that functions as a carrier generator is referred to as "carrier OC".

As shown in Fig. 1, the FM sound synthesis apparatus according to the present embodiment performs FM operation using two operators (modulator OM and carrier OC) for one sound, and has a sound signal having a desired spectrum configuration. Synthesize. This sound synthesis apparatus includes a carrier waveform generator (carrier OC) for generating a carrier waveform signal (carrier signal) which is the basis of a sound signal, and a modulation waveform signal (modulation wave signal) for modulating the carrier waveform signal into a desired sound signal. It consists of a modulation waveform generator (modulator OM). In each of these waveform generators, various parameters such as FB (feedback) parameters, waveform parameters (that is, waveform change parameters), pitch parameters, and envelope parameters can be input, respectively, and finally output from the carrier OC according to these parameters. It is possible to control the waveform shape of the sound signal. Although described later in detail, in the sound synthesis apparatus described in the first embodiment, at least the loop point address LP and the return point address RP as waveform parameters (i.e., waveform change parameters) are referred to herein as appropriate relative values (e.g., A relative address value, etc.) is variably set or selected for each operator and provided to each operator, and in each operator in an address range based on the loop point address LP and the return point address RP, Control is performed to repeatedly read a desired basic waveform (sine wave or the like) from the waveform table (wave table WT described later) on a round trip. By doing this, the user realizes various tones simply by setting the loop point address LP and the return point address RP to any one of intermediate points other than the start address SA and the end address EA of the basic waveform. The sound signal having a more complicated waveform shape can be easily generated. Since other parameters included in waveform parameters other than the loop point address LP and the return point address RP, FB (feedback) parameters, pitch parameters, and envelope parameters are well-known, the description thereof is omitted here. do. The waveform parameter (that is, the waveform change parameter) is generated based on the tone selection operation by the user, the tone change or setting operation, or the like, or based on the tone selection information or tone control information included in the performance data. To that end, waveform change parameters comprising tables or circuits or algorithms or tone data memories, etc., which generate appropriate waveform change parameters in accordance with the output data from the tone selection or control operator or inputs such as tone selection or control information, as necessary. What is necessary is just to install a generation means suitably.

As shown in Fig. 2, each operator (modulator OM or carrier OC) includes at least selector S1, phase generator (phase generator) PG, address generator AG, wave table WT, envelope generator EG, adder K1, multiplier J1, respectively. It is configured by. The selector S1 does not output the magnetic feedback signal from the input terminal of the selector S1 when the FB parameter is set to "0", that is, the output waveform of the operator. When the output waveform of the operator is set to self-feed back, the self-feedback signal from the input terminal of the selector S1 is output. That is, as shown in Fig. 1, the modulator OM has a so-called self-feedback function that further modulates the output waveform by feeding back its output waveform to the input side. As a result, a modulated signal having a more complicated waveform can be formed. Therefore, by setting the FB parameter, it is controlled whether or not to operate this self feedback function. However, as can be understood from FIG. 1, since only the modulator OM has such a self feedback function and the carrier OC does not have the above function, the carrier OC does not output a magnetic feedback signal. Therefore, in the carrier OC, the FB parameter is used as a parameter for determining whether to input the output waveform from the modulator OM.

The phase generator PG generates a corresponding pitch frequency number in accordance with pitch parameters, such as pitch and octave information, input according to user operation of a performance operator (for example, a keyboard, etc.). The pitch frequency number is numerical data for determining the pitch frequency (pitch) of a waveform to be generated corresponding to a key code pre-assigned for each operated performance operator such as a pressed key or included in performance data such as MIDI. Frequency information (phase increment value or decrease value). Although details will be described later (see FIGS. 3 and 4), in the phase generator PG, when the loop point address LP and the return point address RP are set as waveform parameters, the loop point address LP and the return are made. The generated pitch frequency number is corrected according to the point address RP. The pitch frequency number generated from the phase generator PG in this manner is added to the output from the selector S1 by the adder K1 and provided to the address generator AG.

The address generator AG is a circuit for generating periodically changing phase information in a range corresponding to a phase angle (0 to 2π radians) over one cycle. Specifically, the address generator AG accumulates the pitch frequency number provided from the phase generator PG. (It may be addition or subtraction.) A waveform read address signal is generated. This waveform read address signal is address information for reading the basic waveform stored in the wave table WT. The wave table WT is a memory or waveform generation table storing plural kinds of basic waveforms, and each waveform data (sample data) for one cycle of various waveforms such as sinusoidal wave, triangle wave, sawtooth wave, etc. is stored as a basic waveform. The sample point is stored. In the wave table WT, the absolute address storing the first sample data of the basic waveform is the start address SA, and the absolute address storing the last sample data of the basic waveform is the end address EA. Which of the plurality of basic waveforms is used may be appropriately selected according to the user's selection, tone color selection information, or the like.

First, in the sound synthesis apparatus described in the first embodiment, as a waveform parameter, a relative value which starts reading the basic waveform up to the start address SA (that is, in the negative direction of decreasing address value) ( For example, the loop point address LP, which is a relative address value, etc., returns a read back to the address and starts reading the basic waveform again toward the end address EA (that is, in the positive direction in which the address value increases). The return point address RP, which is a relative value (e.g., a relative address value or the like), can be appropriately set, and this can be provided to each operator. When each operator reads the desired basic waveform (sample data) from the wave table WT, the loop point address LP and the return point address RP are referred to from the start address SA to the loop point address LP. When the basic waveform is read sequentially (first reading), the basic waveform is read (second reading) by moving the address back from the loop point address LP to the return point address RP. When the data is returned to the return point address RP again, the basic waveform is read sequentially (the third reading) up to the end address EA to control the reading of the basic waveform. Therefore, in the address range (section) from the loop point address LP to the return point address RP, the corresponding basic waveform is repeatedly read three times (duplicately) (one reading in other ranges). just). The reading of the basic waveform from the wave table WT is controlled in accordance with the address progression based on the waveform read address signal output from the address generator AG. The waveform read address signal output from this address generator AG will be described later (see FIGS. 5 and 6).

The envelope generator EG outputs an envelope signal in accordance with the input envelope parameter, and multiplies this by a waveform generated by reading the basic waveform from the wave table WT to determine the envelope of the signal to be finally output. In the sound modulation apparatus of the frequency modulation arithmetic type shown in FIG. 1, the signal output from an operator is used as a carrier signal, a modulation wave signal, etc. as mentioned above.

Next, the details of the phase generator PG and the address generator AG included in the above-described operator will be described. First, the phase generator PG will be described with reference to FIGS. 3 and 4. 3 is a circuit diagram showing a concrete embodiment of the phase generator PG. Fig. 4 is a diagram showing an AG output waveform (however, the offset due to the start address SA is omitted) accumulated in the pitch frequency number output from the phase generator PG over time. Here, in Fig. 4A, when there is no repeated reading of the basic waveform (i.e., the loop point address LP and the return point address RP are not set, the correction of the pitch frequency number described later is not performed. Fig. 4B shows a case where there is repeated reading of the basic waveform (i.e., the loop point address LP and the return point address RP are set, and the pitch frequency described later). The AG output waveform diagram in the case where the number is corrected). In this first embodiment, the reading of the section specified by the loop point address LP and the return point address RP, which are waveform change parameters, is repeated at least once in duplicate. In the example of FIG. 4B, the section specified by the loop point address LP and the return point address RP proceeds in the first and positive directions first and then returns from LP to RP in the reverse direction. And return to the positive direction from the RP to the LP again, and the same section (the section from the RP to the LP) totals in the reverse direction and the positive direction, in addition to one reading in the normal plus direction. It is read twice (duplicately).

As shown in FIG. 3, the phase generator PG is comprised by the circuit containing at least the shifter B, the correction coefficient calculator E, and the multiplier J2. The shifter B is for octave shifting the pitch frequency number FUNM proportional to the pitch frequency (pitch) corresponding to the pitch input as the pitch parameter in accordance with the octave information OCT input as the pitch parameter as well. For example, the shifter B shifts the pitch frequency number FNUM by the number of bits indicated by the octave information OCT and outputs the pitch frequency number FNUMl. Therefore, when not octave shifted, the pitch frequency number FUNM corresponding to the input pitch and the pitch frequency number FNUM1 after the octave shift, which are outputs from the shifter B, are the same. The output from the shifter B is provided to the multiplier J2 and multiplied by the correction coefficient E1 output from the correction coefficient calculation unit E. The correction coefficient calculating unit E calculates the correction coefficient E1 based on the loop point address LP and the return point address RP input as the waveform parameters, and provides the correction coefficient E1 to the multiplier J2, thereby outputting the pitch frequency number outputted from the shifter B ( FNUM1) is corrected. The correction coefficient E1 is calculated by the following equation (1).

Here, "L" is an address range that stores a desired basic waveform for one cycle in the wave table WT (that is, the address length from the start address to the end address), and "LP" is a loop point address, and "RP" is Return point address. In Equation 1, as shown in Fig. 4B, the number of overlapping repetitions is set to "2". When the redundant number of repetitions is represented by an arbitrary number n, Equation 1 is rewritten as Equation 2 below. In other words, the repetition number n can be arbitrarily changed.

The correction coefficient E1, which is the output from the correction coefficient calculator E, and the pitch frequency number FNUM1 after the shift, which is the output from the shifter B, are provided to the multiplier J2 and multiplied by the multiplier J2 so that the pitch frequency number after correction ( FNUM2) is calculated and output to the address generator AG. Although described later in detail, when the sample value data of the basic waveform in the wave table WT is read repeatedly according to the pitch frequency number FNUM1 before correction between the return point address RP and the loop point address LP, Since the pitch of the generated waveforms may be changed (see the waveforms shown by dashed lines in FIG. 6 to be described later), the pitch frequency number (FNUM1) is previously determined according to the range in which the basic waveform is repeatedly read in advance. ) Is corrected so that the pitch of the waveform generated by repeatedly reading the basic waveform from the wave table WT is not changed (see also the waveform shown in solid lines in FIG. 6 described later). That is, the repetition of the same section is a delay factor in the progress of the phase information, and thus compensates for this delay factor so that the progress of the phase information is not delayed, i.e., compensated to ensure a desired pitch period.

As shown in Fig. 4A, when the loop point address LP and the return point address RP are not provided as waveform parameters, that is, when there is no repetitive reading of the waveform, an address described later. In generator AG, the pitch frequency number FNUM1 is sequentially added at predetermined regular time intervals [Delta] t, and the pitch frequency number accumulation value at each time is calculated. When the loop point address LP and the return point address RP are not provided, since the correction coefficient by the correction coefficient calculator E is calculated as "1", the pitch frequency number FNUM1 is not corrected and remains as it is. It is used for accumulation. In the embodiment shown in Fig. 4A, the time taken to reach the address length L of the basic waveform for one cycle, that is, the time taken to read the one cycle waveform from the wave table WT is "t12". This time corresponds to the pitch (cycle of one cycle) when the basic waveform is read from the wave table WT.

On the other hand, as shown in Fig. 4B, even when the loop point address LP and the return point address RP are provided as waveform parameters, that is, when the waveform is repeatedly read, Similarly, the pitch frequency number accumulation value at each time is calculated by sequentially adding the pitch frequency numbers at predetermined regular time intervals Δt, but in this case, the correction coefficient by the correction coefficient calculator E is "1. Or more &quot;, the corrected pitch frequency number FNUM2 is used for accumulation. In the embodiment shown in Fig. 4B, the relative address value "4L / 6" with respect to the address length L of one cycle waveform as the loop point address LP, and one cycle waveform as the return point address RP. Since the relative address value "L / 6" with respect to the address length L is set respectively, the correction coefficient is calculated as "2" according to the above expression (1). Therefore, the pitch frequency number FNUM2 corrected to twice the pitch frequency number FNUM1 before correction is sequentially accumulated, and the address length of one cycle waveform is doubled at a speed twice as compared with the case of FIG. To reach. That is, the time to reach the address length of one cycle waveform becomes "t6". In the case of simple reading, since this time corresponds to the pitch, when reading the basic waveform from the wave table WT in comparison with the above case, The phase change rate of is to be changed.

Next, the address generator AG will be described with reference to FIGS. 5 and 6. 5 is a circuit diagram showing a specific embodiment of the address generator AG. Fig. 6 is a diagram showing an AG output waveform output from the address generator AG. However, in FIG. 6, in order to make the description easy to understand, when the repeated reading of the basic waveform is performed, the case of "no correction" with respect to the pitch frequency number is indicated by a dashed line, and the case of "with correction" is indicated by solid lines, respectively. The difference in the output signal with or without pitch frequency number correction in the above-described phase generator PG will be described.

The corrected pitch frequency number FNUM2 output from the phase generator PG is provided to the address generator AG, and the address generator AG outputs a waveform read address signal OUT for reading sample data of the basic waveform from the wave table WT. . In order to make the description easy to understand, the address generator AG is described here by function. That is, by dividing the address generator AG functionally large, the function range for generating the waveform read address by accumulating the pitch frequency number, and the address range corresponding to the basic waveform based on the loop point address LP and the return point address RP. It can be divided into the function Y for performing the control to be read repeatedly from and having a circuit (or arithmetic software) for realizing each of these functions. The circuit which realizes the said function X is comprised including the selector S2 and S3, the delay circuit D, the gate circuit G, the adder K2, and the subtractor M at least. On the other hand, the circuit for realizing the function Y includes at least an inverter P, a selector S2, comparison circuits H1 and H2, delay circuits D1 and D2, EXOR circuits O1 and O2, OR circuits N1 and N2, a counter CN, and a decoder Q. It is composed. Of course, each of the circuits for realizing the function X and the function Y is not limited to the above.

First, a circuit for realizing the function X will be described. The corrected pitch frequency number FNUM2 output from the phase generator PG is provided to the selector S2. The selector S2 outputs the provided pitch frequency number FNUM2 as it is when the input signal from the decoder Q to be described later is "0", and the pitch frequency number provided when the input signal from the decoder Q to be described later is "1". A pitch frequency number FNUM2 in which plus / minus of (FNUM2) is inverted by the inverter P is output to the adder K2. Since the operation of the decoder Q (the set of the input signal "0" or "1") will be described later, a description thereof will be omitted. The adder K2 is composed of an output from the selector S2 (either the pitch frequency number FNUM2 or the pitch frequency number FNUM2 in which plus / minus is reversed), the delay circuit D, the subtractor M, the selector S3, and the gate circuit G. The output from the circulation circuit is added to calculate the accumulated value of the pitch frequency number FNUM2. Here, the pitch frequency number FNUM2 is numerical data after correction in proportion to the pitch assigned to the pressed key or to the pitch frequency (pitch) corresponding to the key code included in the performance data such as MIDI. It corresponds to a phase increment value. Therefore, the accumulated value obtained by repeatedly calculating the pitch frequency number FNUM2 for each regular time interval Δt is phase information which changes in time, which is relative in the storage area storing a basic waveform for one cycle from the wave table WT. Corresponds to the address. The accumulated value of the pitch frequency number FNUM2 calculated in the adder K2 is provided to the delay circuit D, the subtractor M, and the comparison circuits H1 and H2 of the circulating circuit, respectively.

In a circulating circuit comprising a delay circuit D, a subtractor M, a selector S3, and a gate circuit G, in order to accumulate the pitch frequency number FNUM2, the accumulation value of the pitch frequency number FNUM2 is delayed by one sampling period to the adder K2. to provide. In other words, the delay circuit D provides the pitch frequency number accumulation value calculated at a time delayed by the time? T which is one sampling period output from the adder K2, to one of the input terminals of the selector S3. The other input terminal of the selector S3 is provided with a value other than the most significant bit MSB of the data output from the subtractor M. The subtractor M subtracts the address length L from the pitch frequency number accumulation value output from the adder K2. In the selector S3, when the most significant bit MSB of the data output from the subtractor M is "1", other than the most significant bit MSB is output to the gate circuit G, and the said most significant bit MSB is "0". Outputs a pitch frequency number accumulation value, which is an output from the delay circuit D, to the gate circuit G. In this case, when the pitch frequency number accumulation value overflows, accumulation occurs again from the minimum value. As a waveform read address signal output from the address generator AG, a waveform having a repetition period is output. In the gate circuit G, the pitch frequency number accumulation value is provided to the adder K2 until the key-on pulse KONP, which is a pulse signal generated along with the key-on, is newly input. When the key-on pulse (KONP) is newly input, the pitch frequency number accumulation value is not provided to the adder K2, so that the accumulation of the pitch frequency number is newly started based on the pitch frequency number of the pitch corresponding to the key-on key. To start. In the adder K2, the newly input pitch frequency number FNUM2 and the pitch frequency number accumulation value from the gate circuit G are added.

Next, a circuit for realizing the function Y will be described. The return point address RP and the loop point address LP are applied to the input terminals of the comparison circuits H1 and H2, respectively. In addition, the pitch frequency number accumulation value (relative address signal) which is the output from the adder K2 is applied to the other input terminal of the comparison circuits H1 and H2. The output of the comparison circuit H1 for comparing the return point address RP and the pitch frequency number accumulation value is applied to one terminal of the OR circuit N1 via the delay circuit D1 and the EXOR circuit O1. On the other hand, the output of the comparison circuit H2 for comparing the loop point address LP and the pitch frequency number accumulation value is applied to the other terminal of the OR circuit N1 via the delay circuit D2 and the EXOR circuit O2. The output of the OR circuit N1 is provided to the counter CN, which sends a counter value, which is the result of counting in accordance with the output from the OR circuit N1, to the decoder Q. As shown in FIG. 4, when the return point address RP and the loop point address LP are provided, the decoder Q is &quot; 1 &quot; when the counter value from the counter CN is "2" or "3". Is output to the selector S2 in the other cases. The counter value for determining "0" or "1" output from the decoder Q to the selector S2 is one example. The method of providing the return point address RP and the loop point address LP and the pitch frequency number FNUM2 It goes without saying that the counter value may be a different value depending on the magnitude or their relationship.

In addition, the counter CN is used to output from the OR circuit N2 which takes as input the most significant bit MSB of the data output from the subtractor M and the key-on pulse KONP, which is a pulse signal generated in conjunction with the key-on. Therefore, the count value of the counter CN is reset to "0".

First, when the key-on pulse KONP is input to the OR circuit N2 in conjunction with the key-on, a reset signal is applied to the counter CN by the OR circuit N2, so that the matter count value becomes "0". The output signal of Q also becomes "0". The selector S2 then selects the input pitch frequency number FNUM2, and the addition of the pitch frequency number FNUM2 is started. That is, when a key on pulse (KONP), which is a pulse signal generated along with the key on, is newly input to the OR circuit N2, from that point on, the newly input positive / minus non-inverted pitch frequency number (FNUM2) Accumulation is initiated according to When the pitch frequency number accumulation value (relative address signal) reaches the return point address RP (the first time arrival), the OR circuit because the EXOR circuit O1 becomes "1" and the EXOR circuit O2 becomes "0", N1 becomes "1" and the counter CN counts the count value from "0" to "1". Since the decoder Q outputs "0" according to the count value "1", the selector S2 continues the addition of the pitch frequency number FNUM2 to the pitch frequency number accumulation value (relative address signal) so that the pitch frequency number FNUM2 Select). Here, after the pitch frequency number accumulation value (relative address signal) reaches the return point address RP for the first time, &quot; 1 &quot; is always output by the comparison circuit H1. "0" is always output to one terminal of the OR circuit N1.

When the pitch frequency number accumulation value (relative address signal) reaches the loop point address LP (first time arrival), the output signal of the decoder Q is changed from "0" to "1". That is, when the first loop point address LP is reached, the EXOR circuit O2 becomes "1", and as described above, "0" is always output from the EXOR circuit O1, so that the OR circuit N1 is " 1, and the counter CN counts the count value from "1" to "2". The decoder Q outputs "1" in accordance with the count value "2". Therefore, the selector S2 selects the pitch frequency number FNLTM2 in which plus / minus is inverted by the inverter P. Therefore, after the pitch frequency number accumulation value (relative address signal) reaches the first loop point address LP, the pitch frequency number accumulation value is subtracted. When the pitch frequency number FNUM2 is newly input and the first subtraction of the pitch frequency number accumulation value is started, in this embodiment, "0" is output from the EXOR circuit O1 as described above. Since the EXOR circuit O2 remains "1", the OR circuit N1 becomes "1", and the counter CN counts the count value from "2" to "3". Further, the count value "3" does not change until the subtracted pitch frequency number accumulation value (relative address signal) reaches the return point address RP again (second time arrival). The decoder Q outputs "1" according to the count value "3". Therefore, during the count value "3", that is, until the pitch frequency number accumulation value reaches the return point address RP again (the second arrival), the pitch frequency number accumulation value is Will be subtracted.

When the pitch frequency number accumulated value (relative address signal) which has been subtracted in this way reaches the return point address RP again (second time arrival), the output signal of the decoder Q is changed from "1" to "0". That is, when the second return point address RP is reached, the EXOR circuit O1 is set from "0" to "1", and since the EXOR circuit O2 is "0", the OR circuit N1 is set to "1". The counter CN counts the count value from "3" to "4". The decoder Q outputs "0" in accordance with the count value "4". Therefore, the selector S2 selects the pitch frequency number FNUM2. Therefore, after the subtracted pitch frequency number accumulation value (relative address signal) reaches the return point address RP again, the pitch frequency number FNUM2 in which plus / minus is not inverted with respect to the pitch frequency number accumulation value is again present. It is added. When the pitch frequency number FNUM2 is newly input and the first addition of the pitch frequency number accumulation value is started again, in this embodiment, the EXOR circuit O1 is left as "1" and the EXOR circuit O2 is left as "0". Therefore, the OR circuit N2 becomes "1", and the counter CN counts the count value from "4" to "5". The count value "5" does not change until the pitch frequency number accumulation value (relative address signal) reaches the loop point address LP again (second time arrival). Since the decoder Q outputs "0" in accordance with the count value "5", the pitch frequency number accumulation value is added during the count value "5".

Next, when the pitch frequency number accumulation value (relative address signal) reaches the loop point address LP again (second time arrival), the output signal of the decoder Q differs from "0" unlike when the first time is reached. It does not change to "1", but remains "0". That is, when the second loop point address LP is reached, since the EXOR circuit O1 is "0" and the EXOR circuit O2 is "1", the OR circuit N1 is "1" and the counter CN is a count value. Is counted from "5" to "6". The decoder Q outputs "0" in accordance with the count value "6". That is, unlike the first arrival, the selector S2 does not select the pitch frequency number FNUM2 in which plus / minus is inverted by the inverter P. Therefore, after the pitch frequency number accumulation value (relative address signal) reaches the second loop point address LP, the pitch frequency number FNUM2 in which plus / minus is not inverted with respect to the pitch frequency number accumulation value is returned. It is added as it is. When "1" is provided as the most significant bit (MSB) of data from the subtractor M described above, the counter value of the counter CN is reset to "0".

As described above, the pitch frequency number accumulation value generated by sequentially adding the input pitch frequency number FNUM2 at regular time intervals corresponds to the relative address in the storage area storing the basic waveform for one cycle. . In order to read the basic waveform from the wave table WT, it is necessary to convert this pitch frequency number accumulation value (relative address signal) into an absolute address signal. Therefore, in the adder K3, the pitch frequency number accumulated value (relative address signal) is converted into an absolute address signal by adding the start address SA which is an absolute address. By accessing the wave table WT in accordance with the absolute address signal output from the adder K3, sample data of a predetermined basic waveform (e.g., a sine wave or the like) stored in the wave table WT is read in response from the wave table WT.

In this manner, in address generator AG, the pitch frequency number FNUM2 is repeatedly calculated and accumulated at regular time intervals, thereby generating a waveform read address signal. As shown in Fig. 6, when the loop point address LP and the return point address RP are provided as waveform parameters, first reading of the sample value data from the start address SA is started at time "t0". . It increases by an address corresponding to the pitch frequency number FNUM2 at predetermined regular time intervals, but from the time "t4" when the address value reaches the loop point address LP, the pitch frequency number every predetermined time interval. It is subtracted by the address equivalent to (FNUM2). Then, from the time &quot; t7 &quot; when the address value reaches the return point address RP, it is increased again until the address length L is reached for each address corresponding to the pitch frequency number FNUM2 at predetermined regular time intervals. do. In this way, a waveform read address signal having an absolute address as long as one waveform is read is generated. In this case, the time until reaching the address length L of one cycle waveform becomes "t12", and the pitch frequency number FNUM1 before the correction is input as it is as an address (see Fig. 4A). It reads at the same pitch as. In other words, by correcting the pitch frequency number in advance in the phase generator PG, the sameness of the pitch in the waveform generated by repetitive reading of the waveform is maintained.

As described above, when the basic waveform is read from the wave table WT according to the waveform read address shown in Fig. 6, for example, as shown in Fig. 6, a waveform having a waveform shape as shown in Fig. 7 can be generated. Can be. FIG. 7 is a diagram showing an example of waveforms generated when a sine wave is read from the wave table based on the AG output waveform shown in FIG. 6. As can be understood from FIG. 7, as described above, the waveform readout control is performed to repeatedly read the basic waveform between the loop point address LP and the return point address RP, so that Only the waveform shape can be changed without changing the pitch (frequency) of one cycle. Therefore, the user can greatly change the waveform shape of the original basic waveform to read the basic waveform by appropriately setting the loop point address LP and the return point address RP, and the read waveform By using the modulation operation, it is possible to easily generate a sound signal having a more complicated waveform shape, which realizes various tones. In this manner, the modulator OM shown in FIG. 1 generates a modulated wave signal by reading a fundamental waveform from the wave table WT in accordance with the pitch frequency number accumulation value. On the other hand, in the carrier OC, a carrier signal is generated by reading a fundamental waveform from the wave table WT according to the pitch frequency number accumulation value, and the modulated sound signal is added by adding the modulated wave signal output from the modulator OM and the generated carrier signal. You can print

In the above-described embodiment, the corresponding basic waveform is looped once in the address range from the loop point address LP provided as the waveform parameter to the return point address RP so as to be repeatedly read out. You may provide as a waveform parameter. In this case, when correcting the pitch frequency number, the correction coefficient is calculated in consideration of the loop number as well as the loop point address LP and the return point address RP, as well as the loop number, whereby the pitch is temporarily changed.

In the above-described embodiment, the relative address values of the two points of the loop point address LP and the return point address RP are provided as waveform parameters, and the basic waveform is repeatedly read between them, but the present invention is not limited thereto. For example, after providing three relative address values (e.g., A1 < A2 < A3) as waveform parameters, proceeding from address A1 to address A3, proceeding backward from address A3 to address A2, and again address The basic waveform may be repeatedly read from A2 to the address A3. Alternatively, four relative address values (for example, A1 < A2 < A3 < A4) are provided as waveform parameters, proceed from address A1 to address A4, and then reverse from address A4 to address A2. After proceeding from A2 to address A3, it proceeds backward from address A3 to address A2 (or address A1), and again proceeds from address A2 (or address A1) to address A4 so that the basic waveform can be read repeatedly. do. By doing so, it is possible to generate a waveform having a more complicated waveform shape only by reading the basic waveform from the wave table WT. Of course, even in such a case, the correction coefficient is calculated in consideration of repetition, and of course, the pitch is temporarily changed. Of course, in the case described above, the circuit for realizing the function Y which performs the control of repeatedly reading the basic waveform in the address generator AG shown in Fig. 5 in the corresponding address range is changed in accordance with each of the above aspects. Of course it is necessary.

In addition, it is not necessary to include the progression in the reverse direction (plus and reverse return), and even if the designated section (the section from RP to LP) proceeds in the positive direction (or the reverse direction), one or more times may be repeated. do. In addition, repetition of progressing in the same direction (plus or reverse direction) requires returning by jumping of the sample point at the repeating point, and lacks smoothness in the connection of the sample data at that part. Sample data may be smoothly connected by interpolation between the sample data and the like.

Next, a second embodiment will be described. In the sound synthesis apparatus described in the second embodiment, as the waveform parameter, the sample data of the corresponding sample point is held for a predetermined time, that is, the progress of the waveform read address of the basic waveform is temporarily stopped at the sample point. A stop point address (SP) for specifying a relative address position of the sample point (temporary sample point) to be controlled so as to be controlled, and a stop time for determining a time width for pausing the progress of the waveform read address of the basic waveform. ST) can be set arbitrarily for each operator, and this can be provided to each operator as a waveform change parameter. When each operator reads the desired basic waveform (sample data) from the wave table WT, the waveform read address is sequentially read from the start address SA to the stop point address SP while first referring to the stop point address SP. It advances and reads a basic waveform. When the basic waveform is sequentially read out to the stop point address SP, the progress of the waveform read address of the basic waveform is temporarily stopped from that point in time. When the time has elapsed by the stop time defined by the stop time ST, the progress of the waveform read address is resumed sequentially from the stop point address SP to the end address EA, and the basic waveform is read.

FIG. 8 is a circuit diagram showing a specific example of the phase generator PG in the second embodiment, which is configured in the same manner as in FIG. 3, but the correction coefficient E2 generated in the correction coefficient calculator E is different from that in the first embodiment. FIG. 9 is a diagram showing an AG output waveform in which the pitch frequency number output from the phase generator PG is accumulated over time in the second embodiment (however, the offset due to the start address SA is omitted). Here, Fig. 9A shows a case where the stop of the progress of the waveform read address of the basic waveform is "no" (i.e., the stop point address SP and the stop time ST are not set, and the pitch frequency number described later is shown. Fig. 9B is a diagram showing AG output waveforms when no correction is made (Fig. 9B) when there is a stop in the waveform read address of the basic waveform (i.e., the stop point address SP and the stop time ST). Is the AG output waveform diagram of the case where the pitch frequency number is corrected and is described later).

In Fig. 8, the correction coefficient calculator E calculates the correction coefficient E2 based on the stop time ST input as the waveform change parameter, and provides it to the multiplier J2 to correct the pitch frequency number FNUMl output from the shifter B. do. The correction coefficient E2 is calculated according to the following equations (3) and (4).

Where T is the period of the pitch frequency (pitch) of the waveform to be generated, and L is the address range (i.e., the address length from the start address to the end address) that stores the desired basic waveform for one cycle in the wave table WT. is the sampling frequency and FNUM1 is the pitch frequency number after the shift output from the shifter B.

The correction coefficient E2, which is the output from the correction coefficient calculator E, and the pitch frequency number FNUM1 after the shift, which is the output from the shifter B, are provided to the multiplier J2 and multiplied by the multiplier J2, thereby correcting the pitch frequency number after correction ( FNUM2) is calculated and output to the address generator AG. Although described later in detail, when the progress of the waveform read address of the basic waveform is stopped from the time when the stop point address SP is reached until the time specified by the stop time ST has elapsed, the basic waveform in the wave table WT As compared with the case where the sample value data is read as it is without pausing the progress of the waveform read address according to the pitch frequency number FNUM1 before correction, the waveform generated by the amount of time for which the progress of the waveform read address is paused is delayed. Since the pitch may change (see the waveform shown by the dashed line in FIG. 11 below), the pitch frequency number FNUM1 is corrected in advance according to the stop time ST, thereby providing the basic waveform. Even if the progress of the waveform read address is paused, one cycle (pitch) of the generated waveform does not pause. There is no change compared with the case (refer also to the waveform shown by the solid line in FIG. 11 below).

As shown in Fig. 9A, when the stop point address SP and the stop time ST are not provided as waveform parameters, i.e., when the progress stop of the waveform read address of the basic waveform is "none". In the address generator AG described later, the pitch frequency number FNUM1 is sequentially added at every predetermined time interval Δt, and the pitch frequency number accumulation value at each time is calculated. When the stop point address SP and the stop time ST are not provided, since the correction coefficient E2 by the correction coefficient calculator E is calculated as "1", the pitch frequency number FNUM1 is not corrected and remains as it is. It is used for accumulation.

On the other hand, as shown in Fig. 9B, when the stop point address SP and the stop time ST are provided as waveform parameters, i.e., there is a stop in the waveform read address of the basic waveform. Also in this case, the pitch frequency number accumulation value at each time is calculated by adding the pitch frequency numbers sequentially at predetermined regular time intervals Δt in the same manner as above, but in this case, the correction coefficient calculator E Since the correction coefficient E2 by is calculated to be "1 or more", the pitch frequency number FNUM2 after correction is used for accumulation. In the embodiment shown in Fig. 9B, as the stop point address SP, the relative address value "L / 3" with respect to the address length L of the one cycle waveform is "2" as the stop time ST. Since each is set, the correction coefficient is calculated as "1.2" according to the above formula (1). Therefore, the pitch frequency number FNUM2 corrected to 1.2 times the pitch frequency number FNUM1 before correction is sequentially accumulated, and the address length of one cycle waveform is 1.2 times as compared with the case of Fig. 9A. To reach. That is, the time until reaching the address length of one cycle waveform becomes "t10", and since this time corresponds to the pitch, compared with the above case, the phase change rate when the basic waveform is read from the wave table WT is higher. Will be changed.

Next, the configuration of the address generator AG in the second embodiment will be described with reference to FIGS. 10 and 11. FIG. 10 is a circuit diagram showing a specific embodiment of the address generator AG, in which portions having the same functions as those in FIG. 5 are denoted by the same reference numerals and will not be redundantly described. 11 is a diagram illustrating an AG output waveform output from the address generator AG. In FIG. 11, however, in order to make the description easy to understand, when the basic waveform is read by pausing the progress of the waveform read address, the case of "no correction" for the pitch frequency number is indicated by a dashed-dotted line. Yes "is shown by the solid line, respectively, and the difference of the output signal with or without pitch frequency number correction in phase generator PG mentioned above is demonstrated.

In Fig. 10, the part of the function X for generating the waveform read address by accumulating the pitch frequency number has the same configuration as in Fig. 5. The part of the function Y1 which performs control to temporarily stop the progress of the waveform read address of the basic waveform based on the stop point address SP and the stop time ST is slightly different from the part of the function Y in FIG. The circuit for realizing the function Y1 includes at least the selector S3, the comparators H3 and H4, the counter CN1, the OR circuit N3, and the flip-flop circuit FF.

A circuit for realizing the function Y1 will be described. The stop point address SP is applied to the input terminal of the comparison circuit H3. To the other input terminal of the comparison circuit H3, a pitch frequency number accumulation value (relative address signal) which is an output from the adder K2 is applied. The output of this comparison circuit H3 is applied to the set terminal S of the flip-flop circuit FF. According to this, normally, the output signal of the flip-flop circuit FF is "0", and the selector S3 selects the input pitch frequency number FNUM2, but the pitch frequency number accumulation value (relative address signal) is the stop point address SP. ), The signal is supplied to the flip-flop circuit FF by the comparison circuit H3, and the output signal of the flip-flop circuit FF becomes "1", so that the selector S3 is not a pitch frequency number (FNUM2). 0 "is selected. That is, when the pitch frequency number accumulation value reaches the stop point address SP, the pitch frequency number accumulation value is not added but remains constant. In other words, the progress of the waveform read address is substantially stopped.

On the other hand, the stop time ST is applied to the input terminal of the comparison circuit H4. The counter value, which is the output from the counter CN1, is applied to the other input terminal of the comparison circuit H4. The counter CN1 starts counting when the pitch frequency number accumulation value (relative address signal) reaches the stop point address SP, and the counter value and the stop time ST by this counter CN1 are compared by the comparison circuit H4. do. The output of the comparison circuit H4 is applied to the reset terminal R of the flip-flop circuit FF through the OR circuit N3 between the key-on pulses KONP output at the time of key-on. According to this, when the count value added after the pitch frequency number accumulation value (relative address signal) reaches the stop point address SP coincides with the stop time ST, a signal is sent to the OR circuit N3 by the comparison circuit H4. Since the reset signal is provided from the OR circuit N3 to the flip-flop circuit FF, and the output signal of the flip-flop circuit FF becomes "0", the selector S3 selects the input pitch frequency number FNUM2 again. Done. Therefore, after the stop time ST has elapsed after pausing the progress of the waveform read address, the pitch frequency number FNUM2 is added again to the pitch frequency number accumulated value, so the progress of the waveform read address is resumed. When a key-on pulse (KONP), which is a pulse signal generated along with key-on, is newly input to the OR circuit N, "0" is provided to the selector S2 from the flip-flop circuit FF. Accumulation is started in accordance with the newly input pitch frequency number FNUM2.

As described above, the pitch frequency number accumulation value generated by sequentially adding the input pitch frequency number FNUM2 at regular time intervals corresponds to the relative address in the storage area storing the basic waveform for one cycle. . In order to read the basic waveform from the wave table WT, it is necessary to convert this pitch frequency number accumulation value (relative address signal) into an absolute address signal. Therefore, in the adder K3, the pitch frequency number accumulated value (relative address signal) is converted into an absolute address signal by adding the start address SA which is an absolute address. By accessing the wave table WT in accordance with the absolute address signal output from the adder K3, sample data of a predetermined basic waveform (e.g., a sine wave or the like) stored in the wave table WT is read in response from the wave table WT.

In this manner, in address generator AG, the pitch frequency number FNUM2 is repeatedly calculated and accumulated at regular time intervals, thereby generating a waveform read address signal. As shown in FIG. 11, when the stop point address SP and the stop time ST are provided as waveform parameters, first, reading of the sample value data from the start address SA is started at time "t0". It increases by an address corresponding to the pitch frequency number FNUM2 at every predetermined time interval, but the pitch frequency number at every predetermined time interval from the time "t4" when the address value reaches the stop point address SP. Since &quot; 0 &quot; is added instead of (FNUM2), the address does not increase and becomes constant. Then, from the time "t4" after the change of the address value stops from the time "t6" after the stop time ST has elapsed, the address length L for each address corresponding to the pitch frequency number FNUM2 at every predetermined regular time interval. Is increased until it is reached. In this way, a waveform read address signal having an absolute address as much as one waveform is read is generated. In this case, the time until the address length L of one waveform is reached is "t12", and the waveform is read without pausing the progress of the waveform read address (see FIG. 9A). The waveform is read at the same pitch. That is, when there is a pause, when the input pitch frequency number FNUM1 is addressed as it is, the time until reaching the address length L of one cycle waveform is added by the stop time ST and "t14" is added. The pitch is changed and the situation is bad. Therefore, by correcting the pitch frequency number in advance in the phase generator PG, even if the progress of the waveform read address is paused, the equality of the pitch in the generated waveform is maintained.

As described above, when the basic waveform is read from the wave table WT according to the waveform read address output from the address generator AG, for example, as shown in FIG. 11, a waveform having a waveform shape as shown in FIG. 12 is generated. Can be. FIG. 12 is a diagram showing an example of waveforms generated when a sine wave is read from the wave table based on the AG output waveform shown in FIG. 11. As can be understood from this Fig. 12, as described above, the waveform read control is performed to temporarily stop the progress of the waveform read address of the basic waveform in accordance with the stop point address SP and the stop time ST, Only the waveform shape can be changed without changing the pitch of the output waveform. Therefore, the user can greatly change the waveform shape of the original basic waveform to read the basic waveform by appropriately setting the stop point address SP and the stop time ST, and frequency-modulating the read waveform. By using it for arithmetic, it becomes easy to generate the sound signal of the more complicated waveform shape which realizes various tones. In this manner, the modulator OM shown in FIG. 1 generates a modulated wave signal by reading a fundamental waveform from the wave table WT in accordance with the pitch frequency number accumulation value. On the other hand, in the carrier OC, a carrier signal is generated by reading a fundamental waveform from the wave table WT according to the pitch frequency number accumulation value, and the modulated sound signal is added by adding the modulated wave signal output from the modulator OM and the generated carrier signal. You can print

Further, in the above-described embodiment, the progress of the waveform read address is paused by the stop time ST from the time at which the sample point is reached based on the sample point (stop point address SP) provided as the waveform parameter. It is also possible to temporarily stop the progress of the waveform read address from the previous time by the stop time for reaching the sample point, and to resume the progress of the waveform read address from the time the sample point is reached.

The number of sample points set as the stop point address SP may not be limited to one, or may be a plurality of sample points, and the progress of the waveform read address may be paused for an appropriate time each time the respective stop sample points are reached. In this case, the sum total of the pause time for each stop sample point may be used as the stop time ST, or an arbitrary stop time may be set individually for each stop sample point.

Of course, in the case described above, the control for temporarily stopping the progress of the waveform read address of the basic waveform based on the stop point address SP and the stop time ST in the address generator AG shown in FIG. It goes without saying that the circuit for realizing the function Y1 which performs the function of FIG.

In each of the above-described embodiments, the simplest term frequency modulation operation is performed by time division of one operator (operation unit) using two time slots, but not limited thereto, and a plurality of operators are prepared. By selectively switching the connection mode, the algorithm of the FM operation may be selected to synthesize the sound tones of the desired timbre.

In addition, the basic structure (refer FIG. 2) of the operator demonstrated in the above-mentioned embodiment, and the circuit structure (refer FIG. 3, FIG. 5, FIG. 10) of phase generator PG or address generator AG are not limited to this as an example. . As described above, the operator is not limited to a dedicated hardware circuit, but may be configured as a software program executed by a DSP (digital signal processor), a CPU, or the like. In that case, a software program is combined to realize the arithmetic algorithm shown in Figs. 1 to 3, 5, 10 and the like, and the program is stored in a program memory (storage medium) of a DSP or a CPU.

In addition, of course, any waveform sample data system, such as PCM, DPCM, ADPCM, may be sufficient as the sample value data of the fundamental waveform previously memorize | stored in the memory | storage device.

In addition, although the above-mentioned embodiment showed the example which uses the generated waveform for the frequency synthesizer (FM system) music synthesis apparatus, it is not limited to this, The carrier signal in the amplitude synthesizer (AM system) music synthesis apparatus, It may be used as a modulated wave signal or the like.

In each of the above embodiments, when the frequency numbers are corrected by the correction coefficients E1 and E2, the frequency numbers FNUM1 are used so as not to deviate from the originally intended pitch, but the present invention is not limited thereto. May be intentionally adjusted to be changed to a separate desired pitch.

According to the present invention, a waveform having a complex waveform shape with a large change compared to a basic waveform can be generated simply and richly in control.

Claims (25)

Basic waveform generating means for generating sample data of a sample point according to input phase information among sample data of a predetermined basic waveform comprising a plurality of sample points; Means for specifying at least two sample points for modifying a waveform of the fundamental waveform; Means for obtaining frequency information for setting a frequency of a waveform to be generated; Changing means for changing the obtained frequency information according to the specified interval of at least two sample points; Phase information generating means for generating phase information changed at a rate corresponding to the frequency information based on the changed frequency information; Generating the phase information such that the change of the phase information over the section between the specified at least two sample points is repeated at least once in a cycle of the change of the phase information generated by the phase information generating means. Control means for controlling the progression of the phase information generated by the means Including, By inputting the phase information generated by the phase information generating means into the basic waveform generating means under control by the control means, a waveform in which the basic waveform is deformed in accordance with the phase information whose progression in one cycle is controlled is A waveform generator, characterized by being generated from the basic waveform generator. The method of claim 1, The control means is configured to repeat the phase information generated by the phase information generating means at least once so that the phase information advances in the positive direction and returns in the reverse direction in the interval between the specified at least two sample points. Waveform generator to control the progress. The method according to claim 1 or 2, And the means for specifying at least two sample points can arbitrarily change the positions of the at least two sample points to specify. The method according to claim 1 or 2, A waveform generator capable of changing the number of repetitions. The method of claim 3, A waveform generator capable of changing the number of repetitions. The method according to claim 1 or 2, The changing means includes means for generating correction information according to a predetermined function using the specified interval between the at least two sample points as a variable, and the correction information includes one period of the waveform deforming the basic waveform. And correcting the frequency information so as to have a desired period. The method of claim 6, And the desired period corresponds to one period of the frequency set by the frequency information before the change. The method of claim 6, And the predetermined function is a function for compensating a delay factor based on the redundancy of the interval between the specified at least two sample points. The method of claim 1, When the phase information changes from the minimum value 0 to the maximum value L, and the values of the phase information corresponding to the specified at least two sample points are LP and RP, and 0 <RP <LP <L, The control means, the phase information generated by the phase information generating means, so that the phase information is passed from 0 to LP, then from LP to RP, and then from RP to L. Waveform generator, characterized in that for controlling the progress of. Modulated wave generating means for generating waveforms of modulated waves, carrier generating means for generating waveforms of carrier waves, and waveforms of carrier waves generated by said carrier generating means are added to waveforms of modulated waves generated by said modulating wave generating means. A sound synthesis apparatus of a modulation operation type comprising modulation means for modulating accordingly, At least one of the modulated wave generating means and the carrier generating means, Basic waveform generating means for generating sample data of a sample point according to input phase information among sample data of a predetermined basic waveform comprising a plurality of sample points; Means for specifying at least two sample points for modifying a waveform of the fundamental waveform; Means for obtaining frequency information for setting a frequency of a waveform to be generated; Changing means for changing the obtained frequency information according to the specified interval of at least two sample points; Phase information generating means for generating phase information changed at a rate corresponding to the frequency information based on the changed frequency information; Generating the phase information such that the change of the phase information over the section between the specified at least two sample points is repeated at least once in a cycle of the change of the phase information generated by the phase information generating means. Control means for controlling the progression of the phase information generated by the means Including, By inputting the phase information generated by the phase information generating means into the basic waveform generating means under control by the control means, a waveform in which the basic waveform is deformed in accordance with the phase information whose progression in one cycle is controlled is A sound synthesizer comprising: a waveform generator configured to be generated from the basic waveform generator. Specifying at least two sample points for changing a waveform of a predetermined basic waveform consisting of a plurality of sample points, Obtaining frequency information for setting the frequency of the waveform to be generated; Changing the acquired frequency information according to the specified interval of the at least two sample points; Generating phase information changed at a rate corresponding to the frequency information based on the changed frequency information; The phase information such that the change of the phase information over the interval between the specified at least two sample points is repeated at least once in a cycle of the change of the phase information occurring in the step of generating the phase information; Controlling the progress of the phase information generated in the step of generating a; Inputting the phase information generated in the step of generating the phase information, and outputting sample data of a sample point according to the input phase information among sample data of a predetermined basic waveform including the plurality of sample points; And a waveform obtained by modifying the basic waveform according to the phase information whose progression in one cycle is controlled. The method of claim 11, And the outputting step outputs sample data of the predetermined basic waveform according to the input phase information with reference to a memory or a table. A computer-readable storage medium which stores a group of instructions for causing a computer to execute the following processing procedure, wherein the processing procedure is as follows. Specifying at least two sample points for changing a waveform of a predetermined basic waveform consisting of a plurality of sample points, Obtaining frequency information for setting the frequency of the waveform to be generated; Changing the acquired frequency information according to the specified interval of the at least two sample points; Generating phase information changed at a rate corresponding to the frequency information based on the changed frequency information; The phase information such that the change of the phase information over the interval between the specified at least two sample points is repeated at least once in a cycle of the change of the phase information occurring in the step of generating the phase information; Controlling the progress of the phase information generated in the step of generating a; Inputting the phase information generated in the step of generating the phase information, and outputting sample data of a sample point according to the input phase information among sample data of a predetermined basic waveform including the plurality of sample points; Including, Thereby, the waveform which deform | transformed the said fundamental waveform is produced | generated according to the phase information whose progression in one cycle was controlled, The computer-readable storage medium characterized by the above-mentioned. Basic waveform generating means for generating sample data of a sample point according to input phase information among sample data of a predetermined basic waveform comprising a plurality of sample points; Means for generating a waveform change parameter for changing a waveform of the basic waveform, the waveform change parameter comprising a parameter specifying at least one sample point and a stop time parameter for setting a time for holding the specified sample point; Including, Means for obtaining frequency information for setting a frequency of a waveform to be generated; Changing means for changing the obtained frequency information according to the stop time parameter; Phase information generating means for generating phase information changed at a rate corresponding to the frequency information based on the changed frequency information; In one cycle of the change of the phase information generated by the phase information generating means, the value of the phase information corresponding to the specified at least one sample point is not changed by the time set by the stop time parameter. Control means for controlling the progress of the phase information generated by the phase information generating means so as to hold Including, By inputting the phase information generated by the phase information generating means into the basic waveform generating means under control by the control means, a waveform in which the basic waveform is deformed in accordance with the phase information whose progression in one cycle is controlled is A waveform generator, characterized by being generated from the basic waveform generator. The method of claim 14, And the means for generating the waveform change parameter can arbitrarily change at least one of the parameter specifying the at least one sample point and the stop time parameter. The method according to claim 14 or 15, The changing means includes means for generating correction information according to a predetermined function using the stop time parameter as a variable, and the correction information includes the frequency information such that one cycle of the waveform obtained by deforming the basic waveform becomes a desired period. Waveform generator that is to correct. The method of claim 16, And the desired period corresponds to one period of the frequency set by the frequency information before the change. The method of claim 16, The predetermined function is a waveform generation function that compensates for a delay factor based on maintaining the value of the phase information corresponding to the specified at least one sample point without changing by the time set by the stop time parameter. Device. Modulated wave generating means for generating a waveform of a modulated wave, carrier generating means for generating a waveform of a carrier wave, and waveforms of a carrier wave generated by the carrier generating means are converted into waveforms of a modulated wave generated by the modulating wave generating means. A sound synthesis apparatus of a modulation operation type comprising modulation means for modulating by At least one of the modulated wave generating means and the carrier generating means, Basic waveform generating means for generating sample data of a sample point according to input phase information among sample data of a predetermined basic waveform comprising a plurality of sample points; Means for generating a waveform change parameter for changing a waveform of the basic waveform, the waveform change parameter comprising a parameter specifying at least one sample point and a stop time parameter for setting a time for holding the specified sample point; Including, Means for obtaining frequency information for setting a frequency of a waveform to be generated; Changing means for changing the obtained frequency information according to the stop time parameter; Phase information generating means for generating phase information changed at a rate corresponding to the frequency information based on the changed frequency information; In one cycle of the change of the phase information generated by the phase information generating means, the value of the phase information corresponding to the specified at least one sample point is not changed by the time set by the stop time parameter. Control means for controlling the progress of the phase information generated by the phase information generating means so as to hold Including, By inputting the phase information generated by the phase information generating means into the basic waveform generating means under control by the control means, a waveform in which the basic waveform is deformed in accordance with the phase information whose progression in one cycle is controlled is A sound synthesizer comprising: a waveform generator configured to be generated from the basic waveform generator. Generating a waveform change parameter for changing a waveform of a predetermined basic waveform consisting of a plurality of sample points, wherein the waveform change parameter includes a parameter specifying at least one sample point and a time for holding the specified sample point; Including a stop time parameter to set, Obtaining frequency information for setting the frequency of the waveform to be generated; Changing the acquired frequency information according to the stop time parameter; Generating phase information changed at a rate corresponding to the frequency information based on the changed frequency information; In one cycle of the change of the phase information occurring in the step of generating the phase information, the value of the phase information corresponding to the specified at least one sample point is not changed by the time set by the stop time parameter. Controlling the advancing of the phase information generated by the phase information generating means so as to maintain the result; Inputting the phase information generated in the step of generating the phase information, and outputting sample data of a sample point according to the input phase information among sample data of a predetermined basic waveform including the plurality of sample points; Including, Thereby, the waveform generation method characterized by generating the waveform which deform | transformed the said fundamental waveform according to the said phase information whose progression in one cycle was controlled. The method of claim 20, And the outputting step outputs sample data of the predetermined basic waveform according to the input phase information with reference to a memory or a table. A computer-readable storage medium which stores a group of instructions for causing a computer to execute the following processing procedure, wherein the processing procedure is as follows. Generating a waveform change parameter for changing a waveform of a predetermined basic waveform consisting of a plurality of sample points, wherein the waveform change parameter includes a parameter specifying at least one sample point and a time for holding the specified sample point; Including a stop time parameter to set, Obtaining frequency information for setting the frequency of the waveform to be generated; Changing the acquired frequency information according to the stop time parameter; Generating phase information changed at a rate corresponding to the frequency information based on the changed frequency information; In one cycle of the change of the phase information occurring in the step of generating the phase information, the value of the phase information corresponding to the specified at least one sample point is not changed by the time set by the stop time parameter. Controlling the advancing of the phase information generated by the phase information generating means so as to maintain the result; Inputting the phase information generated in the step of generating the phase information, and outputting sample data of a sample point according to the input phase information among sample data of a predetermined basic waveform including the plurality of sample points; Wherein the waveform obtained by modifying the basic waveform is generated in accordance with the phase information whose progression in one cycle is controlled. Basic waveform generating means for generating sample data of a sample point according to input phase information among sample data of a predetermined basic waveform comprising a plurality of sample points; Means for specifying at least one sample point while specifying a waveform of the basic waveform and specifying a redundant section based on the specific sample point; Means for obtaining frequency information for setting a frequency of a waveform to be generated; Changing means for changing the acquired frequency information according to the length of the specified overlapping section; Phase information generating means for generating phase information changed at a rate corresponding to the frequency information based on the changed frequency information; In one cycle of the change of the phase information generated by the phase information generating means, the change of the phase information is repeatedly repeated in the specified overlapping section based on the specified at least one sample point or Control means for controlling the progress of the phase information generated by the phase information generating means so as to be held Including, By inputting the phase information generated by the phase information generating means into the basic waveform generating means under control by the control means, a waveform in which the basic waveform is deformed in accordance with the phase information whose progression in one cycle is controlled is A waveform generator, characterized by being generated from the basic waveform generator. Specifying at least one sample point and specifying an overlapping section based on the specific sample point in order to change the waveform of the predetermined basic waveform consisting of a plurality of sample points, Obtaining frequency information for setting the frequency of the waveform to be generated; Changing the acquired frequency information according to the length of the specified overlapping section; Generating phase information changed at a rate corresponding to the frequency information based on the changed frequency information; In one cycle of the change of the phase information occurring in the step of generating the phase information, the change of the phase information is repeatedly repeated in the specified overlapping section based on the specified at least one sample point or Or controlling the progress of the phase information generated in the step of generating the phase information so as to be maintained; Inputting the phase information generated in the step of generating the phase information, and outputting sample data of a sample point according to the input phase information among sample data of a predetermined basic waveform including the plurality of sample points; Including, Thereby, the waveform generation method characterized by generating the waveform which deform | transformed the said fundamental waveform according to the said phase information whose progression in one cycle was controlled. A computer-readable storage medium which stores a group of instructions for causing a computer to execute the following processing procedure, wherein the processing procedure is as follows. Specifying at least one sample point and specifying an overlapping section based on the specific sample point in order to change the waveform of the predetermined basic waveform consisting of a plurality of sample points, Obtaining frequency information for setting the frequency of the waveform to be generated; Changing the acquired frequency information according to the length of the specified overlapping section; Generating phase information changed at a rate corresponding to the frequency information based on the changed frequency information; In one cycle of the change of the phase information occurring in the step of generating the phase information, the change of the phase information is repeatedly repeated in the specified overlapping section based on the specified at least one sample point or Or controlling the progress of the phase information generated in the step of generating the phase information so as to be maintained; Inputting the phase information generated in the step of generating the phase information, and outputting sample data of a sample point according to the input phase information among sample data of a predetermined basic waveform including the plurality of sample points; Including, Thereby, the waveform which deform | transformed the said fundamental waveform is produced | generated according to the phase information whose progression in one cycle was controlled, The computer-readable storage medium characterized by the above-mentioned.

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