JP2775633B2 - Music control device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synthesizer-type electronic musical instrument such as an electronic stringed musical instrument such as an electronic guitar, and more particularly to extracting pitch information from an input waveform signal and playing a musical tone accordingly. The present invention relates to a musical tone control device for controlling the pitch of a musical tone.

[Conventional technology]

An electronic device that detects string vibrations and the like as electric signals by playing a guitar or the like and controls a tone generation circuit composed of a digital circuit or the like in accordance with the input waveform signal to synthesize and emit a tone. Musical instruments are being developed.

In particular, in the case where the pitch extraction circuit extracts the pitch frequency from the input waveform signal and the tone generation circuit generates a tone with a pitch corresponding to the pitch frequency, the pitch of the tone directly responds to the input waveform signal. Therefore, it is possible to perform tone synthesis faithful to the performance of the player.

In this type of electronic musical instrument, the pitch of a musical tone is not only determined by the pitch frequency of an input waveform signal at the start of sounding, but when the pitch frequency of the input waveform signal changes thereafter, the pitch extraction circuit Extracts a pitch frequency in real time, generates pitch information according to the pitch frequency, and can change and control the pitch of a musical tone being sounded.

Therefore, for example, in the case of an electronic guitar, a player performs a choking performance (a playing technique in which a finger pressing a string on a fret slides in the longitudinal direction or a right angle direction of the fret to change the tension of the string) and performs an input waveform. When the pitch frequency of the signal, that is, the string vibration waveform signal is intentionally changed, the pitch of the musical tone being generated can be changed according to the operation, and a great performance effect can be added.

In this case, the pitch frequency generally does not change so rapidly. Therefore, if the pitch frequency extracted from the pitch extraction circuit changes suddenly for some reason, the pitch is changed based on this, and the sound is generated. The pitch change of the middle tone becomes unnatural. As the above factor, for example, it is conceivable that the pitch extraction circuit extracts a harmonic component or a noise component other than a fundamental frequency component of the pitch (equal to a so-called pitch frequency).

Therefore, in order to prevent erroneous extraction of the pitch frequency, a conventional pitch extraction type electronic musical instrument is usually provided with means for determining whether or not the extracted pitch frequency is a legitimate change. I have. Specifically, for example, when the currently extracted pitch frequency (or pitch period) does not change much from either of the two previously extracted pitch frequencies (or pitch periods) (for example, 1).
Only when the change is equal to or less than a percentage, a means is provided for controlling to change the pitch currently being generated based on the currently extracted pitch frequency (or pitch cycle).

[Problems to be solved by the invention]

Here, even when the intensity (peak value) of the input waveform signal is considerably weakened, that is, when the string vibration has attenuated considerably after a lapse of time after picking a string, for example, the pitch is to be extracted. Then, while the input waveform signal flows from the pickup to the filter for fundamental wave extraction, the amplifier, and further to the subsequent stage pitch extraction circuit, noise of each circuit element cannot be ignored, and noise removal for removing the noise becomes impossible. Countermeasures are required.

In the above-described conventional example, in order to realize noise removal, it is conceivable that a change width (change rate) allowed between successive pitch frequencies is set to a strict condition.

However, as described above, for example, in an electronic guitar or the like, if the player intentionally changes the pitch frequency of the input waveform signal by performing the choking technique, the pitch frequency may change within a considerable range. In such a state, if the condition of the change width allowed between the continuous pitch frequencies is strict, the intentional change of the pitch frequency based on the above-described choking technique or the like is not regarded as a proper change in the pitch frequency, and the pitch is not changed. It can happen that no changes are made.
Therefore, the pitch of the tone being produced does not follow the choking operation as described above, and the pitch cannot be changed as intended by the player, resulting in an unnatural performance. have.

For example, in the case of an electronic guitar, in addition to choking, in addition to performing glissando, hammering-on and other playing techniques, and performing operations such as arming with a tremolo arm, string tension is intentionally changed. This can happen as well. Further, not only the electronic guitar, but also other electronic musical instruments, the pitch frequency of the input waveform may be intentionally changed by the operation of the player.

SUMMARY OF THE INVENTION An object of the present invention is to make it possible to change the pitch of a musical tone by quickly following the intentional operation of changing the pitch frequency of an input waveform signal by a player, and to reduce the intensity of the input waveform signal. Another object of the present invention is to enable stable pitch change that is less affected by noise.

[Means for solving the problem]

According to the present invention, for example, a musical tone realized as an electronic stringed musical instrument (electronic guitar) of a type in which a metal string vibration is detected as an input waveform signal by a pickup, pitch information is extracted therefrom, and the pitch of the musical tone is controlled by the pitch information. It is a control device.

Then, first, there is provided a pitch extracting means for extracting pitch information from the input waveform signal. The means digitizes, for example, an input waveform signal obtained in advance, sequentially detects a valid peak value and a zero-cross time immediately after the digital signal from the digital waveform, and sets a set of the valid peak value and the zero-cross time immediately after or immediately before the valid peak value. Is a means for extracting pitch information, that is, a pitch cycle, as an interval between each zero crossing time. Alternatively, it is means for extracting a pitch cycle as an interval between each peak value. Of course, other pitch extraction techniques may be used.

Next, the intensity extracting means is means for sequentially extracting the intensity information of the input waveform signal in response to the pitch information being sequentially extracted from the pitch extracting means. The means
For example, it is means for extracting a valid peak value of a straight line at a zero crossing time from which the pitch period is extracted.

Furthermore, according to the first aspect of the present invention, only when the current pitch information extracted by the pitch extracting means is a change smaller than a change width determined by a predetermined change threshold with respect to previously extracted pitch information, A pitch information generating means for generating pitch information according to the current pitch information; and the predetermined fluctuation threshold according to the intensity information corresponding to the current pitch information indicating an intensity equal to or less than a predetermined intensity threshold. And a variation threshold control means for decreasing the value of Specifically, for example, only when the current pitch cycle is a change equal to or less than a predetermined fluctuation threshold with respect to the previous and two previous pitch cycles, means for generating pitch information corresponding to the current pitch cycle, When the peak value at the time when the pitch cycle is detected is equal to or smaller than a predetermined threshold, the predetermined variation threshold is changed to a predetermined small value.

In the second aspect of the invention, the pitch information generating means is means for generating pitch information corresponding to pitch information sequentially extracted by the pitch extracting means.

Pitch changing means, when the intensity information corresponding to the current pitch information extracted by the pitch extracting means indicates an intensity equal to or greater than a predetermined intensity threshold, changes the pitch information to be generated to the currently extracted pitch information. The pitch is correspondingly changed, and the intensity information corresponding to the changed pitch information is output to the pitch information generating means, and the intensity information corresponding to the current pitch information indicates an intensity equal to or less than a predetermined intensity threshold. When the pitch information is generated, the pitch information extracted this time and the previously extracted and changed pitch information are averaged and output to the pitch information generating means.

The musical tone control means is means for controlling the pitch of a musical tone based on the pitch information generated by the musical tone information generating means.

[Operation] The operation of the present invention is as follows.

For example, in an electronic stringed musical instrument such as a guitar synthesizer, it is empirically performed that a player performs an operation of intentionally changing a pitch frequency of an input waveform signal by a choking manner or the like when the string vibration is large, that is, when the input waveform signal When the intensity is weak, it is concentrated. Therefore, according to the first aspect of the present invention, when a state in which the intensity of the input waveform signal is high is detected by the intensity information extracted by the intensity extracting means, the pitch information generating means outputs the generated pitch information. Control is performed to allow a relatively large change from the previous sound direction information. As a result, it is possible to quickly follow the intentional change operation of the pitch frequency by the player.

Conversely, when a state in which the intensity of the input waveform signal is weak is detected, the pitch information generating means may allow the generated pitch information to change only slightly from the previous pitch information. Perform control. This makes it possible to effectively remove the influence of the input waveform signal when the intensity of the input waveform signal becomes weak and the input waveform signal is easily affected by noise or the like.

That is, for example, only when the current pitch information extracted by the pitch extracting means is a change equal to or less than a change width determined by a predetermined change threshold with respect to previously extracted pitch information, the pitch information corresponding to the current pitch information is determined. In the means for generating pitch information, when the intensity information corresponding to the current pitch information indicates an intensity equal to or less than a predetermined intensity threshold, the predetermined fluctuation threshold is reduced to a small value, thereby making the pitch extraction condition strict. Thus, the effect of noise can be eliminated.

Further, in the invention according to claim 2, the pitch changing means is adapted to generate a sound to be generated when the intensity information corresponding to the current pitch information extracted by the pitch extracting means indicates an intensity not less than a predetermined intensity threshold. The pitch information is changed in pitch according to the pitch information extracted this time, and the intensity information corresponding to the changed pitch information is output to the pitch information generating means, and the intensity corresponding to the current pitch information is output. When the information indicates an intensity equal to or less than the predetermined intensity threshold, pitch information to be generated is obtained by averaging the pitch information extracted this time and the pitch information extracted and changed before that, and the pitch information obtained. And the intensity information corresponding to the changed pitch information is output to the pitch information generating means, so that if the extracted pitch changes, the pitch information is immediately changed. By generating the pitch information based on this information, the pitch information is naturally changed, and the change is smoothed, thereby preventing the unintended pitch generation of the player. It is possible to prevent a sudden change in pitch due to the influence of noise or the like.

As described above, according to the present invention, the intensity of the input waveform signal in the case where the pitch frequency can be intentionally changed by the player and in the case where the pitch extracting means can extract an erroneous pitch frequency due to the influence of noise or the like are reduced. By using different things,
The pitch can be changed by following the performer's intentional pitch frequency change operation, and the pitch can be changed stably even when the intensity of the input waveform signal is weak. Can be.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail. In the following description, items are sequentially classified in the order of headings surrounded by symbols ｛｝, (), and <<>> and underlined.

<< Structure of Electronic Musical Instrument According to the Present Invention >> In this embodiment, six metal strings are stretched on the body, and a desired string is pressed while pressing a fret (fingerboard) provided below the metal string with a finger. It is realized as an electronic guitar that performs by picking. The appearance is omitted.

 FIG. 1 is an overall configuration diagram of the present embodiment.

First, the pitch extraction analog circuit 1 is provided for each of the six strings (not shown), and outputs each output from a hex pickup for converting the operation of each string to an electric signal.
In particular, by removing harmonic components through a low-pass filter (not shown), each of the six types of waveform signals Wi (i = 1
To 6). Further, each time the sign of the amplitude of each waveform signal Wi changes to positive or negative, a pulse-like zero-cross signal Zi (i = 1 to 6) which becomes high level or low level is generated. Then, these six types of waveform signals Wi and zero cross signals Zi are respectively converted by an A / D converter (not shown) and the like.
The signal is converted into a time-division serially-zero cross signal ZCR and a digital output (time-division waveform signal) D1 and output.

As shown in FIG. 2, the pitch extraction digital circuit 2 includes a peak detection circuit 201, a time constant conversion control circuit 202, a peak value capturing circuit 203, and a zero cross time capturing circuit 204. Each of the circuits shown in FIG.
Based on the serial zero-cross signal ZCR obtained by time-dividing the six strings from (FIG. 1) and the digital output D1, the six strings are time-divided. In the following description, the processing for one string will be described for ease of explanation, and the serial zero-cross signal ZCR and the digital output D1 will be described using the image of a signal for one string. It is assumed that processing is being performed.

In FIG. 2, first, a peak detection circuit 201 detects a maximum peak point and a minimum peak point of the digital output D1 based on the serial zero cross signal ZCR and the digital output D1. For this purpose, the circuit 201 includes a peak hold circuit (not shown) for holding while subtracting (attenuating) the absolute value of the past peak value, although not particularly shown. After detecting the previous peak value, the peak detection circuit 201 sets the absolute value of the digital output D1 after the next serial zero-cross signal ZCR is generated, using the peak hold signal output from the peak hold circuit as a threshold. When the threshold value is exceeded, the timing of the peak value is detected. The detection of the peak value timing is performed for each of the case where the digital output D1 has a positive sign and the case where the digital output D1 has a negative sign. Then, at the peak value detection timing, a maximum peak value detection signal MAX is output for a positive sign, and a minimum peak value detection signal MIN is output for a negative sign. In addition,
Each of these signals is actually a time-division signal for six strings.

Next, the time constant conversion control circuit 202 is a circuit for changing the attenuation rate of the peak hold circuit in the peak detection circuit 201, and the maximum / minimum peak value detection signals MAX and MIN from the peak detection circuit 201, and the It operates under the control of a central control unit (MCP, hereinafter the same) 3 in FIG. This will be described later.

Subsequently, the peak value capturing circuit 203 in FIG. 2 performs a demultiplexing (division) process on the digital output D1 sent out in a time-sharing manner from the peak extraction analog circuit 1 into a peak value for each string. The peak value is held in accordance with the peak value detection signals MAX and MIN from the peak detection circuit 201. And MCP3 (FIG. 1) is the address decoder 4
The maximum peak value or the minimum peak value of the string accessed via (FIG. 1) is determined by the MCP via the bus BUS.
Output to 3 sequentially. In addition to the peak value, the peak value capturing circuit 203 can output the instantaneous value of the vibration of each string.

The zero-cross time acquisition circuit 204 is provided with a serial zero-cross signal ZC from the pitch extraction analog circuit 1 (FIG. 1).
According to R, the output of the time base counter 2041 common to each string is converted to the zero crossing point of each string, more precisely, the maximum / minimum peak value detection signal MAX output from the peak detection circuit 201,
Latch is performed at the zero crossing point immediately after the passage timing of the maximum peak point and the minimum peak point determined by MIN. When this latch operation is performed, the zero-cross time acquisition circuit 204 subsequently outputs an interrupt signal INT to the MCP3 in FIG.
Thus, in accordance with a control signal (described later) output from the MCP 3 via the address decoder 4 (FIG. 1), the string number at which the zero-cross occurred, the zero-cross time corresponding to the latched string, and positive / negative information (described later) The bus BUS
Are sequentially output to MCP3 via.

Also, from the timing generator 205 in FIG.
Timing signals for processing operations of the circuits shown in FIGS. 1 and 2 are output.

Next, returning to FIG. 1, the MCP 3 is
And a RAM 302, and a timer 303. ROM
Reference numeral 301 denotes a non-volatile memory that stores programs for controlling various musical sounds, which will be described later, and a RAM 302 is a rewritable memory used as a work area for various variables and data during the control. The timer 303 is used for a note-off (silence) process described later.

The tone generator 5 includes a tone generator 501 and a D / A converter 502,
It comprises an amplifier 503 and a speaker 504, and emits a tone according to the tone control information from the MCP3. Note that the tone generation circuit 50
Interface (Musical Instrument)
A digital interface (MIDI) is provided, and is connected to the MCP 3 via a dedicated bus MIDI-BUS for transmitting tone control information. When the tone generator 5 is provided in the guitar body, another internal interface may be used.

After the generation of the interrupt signal INT from the above-mentioned zero-cross time acquisition circuit 204 (FIG. 2), the address decoder 4
In accordance with the address read signal AR generated from the MCP 3 (FIG. 1), the zero-crossing time reading circuit 204 sends a string number reading signal ▲ ▼, and then a time reading signal ▲.
▼ (i = 1 to 6) is supplied. Similarly, the waveform reading signal RDAj is supplied to the peak value capturing circuit 203 (FIG. 2).
(J = 1 to 18) is output. Details of these operations will be described later.

<< Schematic Operation of the Embodiment >> The operation of the embodiment having the above configuration will be described below.

First, a schematic operation of this embodiment up to generation of a musical tone will be described.

D1 in FIG. 10 is an analog representation of one string of the digital output D1 output from the pick extraction analog circuit 1 in FIG. This waveform is obtained by picking one string out of six strings of a guitar (not shown) and outputting an electric signal detected from a corresponding pickup as a digital signal. according to the position pressed on the fingerboard), a waveform having a pitch period as shown in FIG. 10 T ₀ through T ₅ and the like are generated.

In this embodiment, the pitch periods T _{0 to} T _{5 and the} like are extracted in real time, so that the MCP 3 in FIG. 1 generates pitch information corresponding to the pitch periods, and the pitch generation circuit 501 in FIG. To produce the musical tone of Therefore, especially when the player changes the tension of the string during the performance by a tremolo arm (not shown), the pitch period of the digital output D1 changes accordingly, and the pitch information also changes in real time accordingly. , Rich expressions can be added to musical sounds.

Further, in this embodiment, when and by detecting the peak value a ₀ ~a ₃ or b ₀ ~b ₃ like the tenth diagram of a digital output D1, MCP3 particularly in FIG. 1 rising (when strings Picking) tone generator 501 to create the volume information based on the maximum peak value a ₀ for
, A musical tone having a volume corresponding to the strength of picking a string can be generated.

Then, after the start of sounding of a musical tone in this embodiment, when changing the tone pitch of the musical tone based on the pitch period are sequentially extracted (e.g. FIG. 10 T ₂ through T _5, etc.), first, the first embodiment As
If the peak value extracted together with the extraction of each pitch cycle is equal to or greater than a predetermined value, it is determined that the intentional pitch change by the player can be made, and the change in the pitch frequency corresponding to the extracted pitch cycle is the same as the previous one. compared to the pitch frequency of the second last, 1/2 even change of up to about ⁵ allowing the pitch changes. Conversely, if the peak value is equal to or less than the predetermined value, it is determined that erroneous pitch extraction can be performed under the influence of noise, and the change in the pitch frequency corresponding to the extracted pitch cycle is the same as the previous one and the previous one. 1/2 ⁷ compared to the pitch frequency
It does not allow pitch changes until it falls below. This makes it possible to quickly follow the intentional pitch frequency change operation performed by the player and, if the peak value (intensity) of the digital output D1 becomes weak and becomes susceptible to noise or the like, the effect is obtained. Can be effectively removed.

As a second embodiment for the pitch change, first, the change of the pitch frequency corresponding to the pitch period is extracted, compared to the pitch frequency of the last and the second last, if up to 1/2 ⁵ or more changes Does not uniformly accept pitch changes. When this condition is satisfied, and the peak value extracted together with the extraction of each pitch cycle is equal to or greater than a predetermined value, the pitch is directly changed at each pitch cycle so as to follow the intentional pitch change by the player. Make changes. Conversely, if the peak value is equal to or less than the predetermined value, the average pitch between the pitch cycle used for the previous pitch specification and the currently extracted pitch cycle is used to absorb the change in pitch cycle due to the influence of noise and the like. The period is calculated, and the pitch is changed according to the average pitch period. As a result, it is possible to prevent a sudden change in pitch due to the influence of noise or the like.

As described above, the pitch can be changed by following the intentional pitch frequency change operation performed by the performer well, and even when the peak value of the digital output D1 is small, the digital output D1 is not easily affected by noise and the like, and is stable. The pitch can be changed. This is a major feature of the present embodiment.

The above operation is time-division-processed for the time-division digital output D1 for the six strings of the guitar, so that the tone generation circuit 501
Can sound the sound of six strings aurally simultaneously. These musical tones can be set to any volume and tone freely, and various effects can be electronically added, so that an extremely large performance effect can be obtained.

<< Operation of Pitch Extraction Digital Circuit >> Regarding the operation of the present embodiment for realizing the above operation,
The details will be described below.

(Schematic Operation) First, the operation of the pitch extraction digital circuit 2 shown in FIG. 1 or FIG. 2 will be described. In the following description, only one string is described, and the serial zero cross signal ZCR, the digital output D1, and the maximum / minimum peak value detection signals MAX and MIN are described using the image of one string. Time division processing has been performed for minutes.

In the circuit 2, the digital output D1 of FIG. 10 for each chord, the peak value a ₀ ~a ₃ or b ₀ extracts ~b _3, etc., the zero crossing time t ₁ ~t ₇ immediately after the respective peak values at the same time And the like, and further extracts information indicating whether the peak value immediately before each zero crossing time is 1 or 0 depending on whether the peak value is positive or negative, and supplies the information to the MCP3 in FIG. Based on this, MCP3 extracts the respective pitch period T ₀ through T _5, etc. of FIG. 10 from the interval of the zero-crossing time, also,
In addition, the above-mentioned various musical tone information is generated, and further, as will be described later, error processing, note-off (silence) processing, lifting on / off processing, and the like are performed.

(Detailed Operation) To this end, the peak detection circuit 201 shown in FIG.
For the digital output D1 input as shown in the figure, first, in the part where the value becomes negative, x0 at the timing when the absolute value exceeds ₀ , and the minimum peak value as shown in FIG. The detection signal MIN becomes high level.

Thus, the peak value acquisition circuit 203 of FIG. 2 is a timing x ₁ immediately after the minimum peak value detection signal MIN is at high level, the wave of the minimum peak value (negative from the digital output D1 to enter separately The high value _b0 (absolute value) is detected and held in a latch (not shown), and the minimum peak value detection signal MIN is returned to a low level.

On the other hand, a serial zero-cross signal ZCR as shown in FIG. 10 is input from the pitch extraction analog circuit 1 in FIG. 1 to the zero-cross time acquisition circuit 204 in FIG. This signal is a signal which is output as a high-level or low-level binary digital signal from a comparator (not shown) in the pitch extraction analog circuit 1 which determines whether the digital output D1 is positive or negative.

Then, the zero-crossing time acquisition circuit 204 outputs the minimum peak value detection signal MIN output from the peak detection circuit 201.
Immediately but that the high level at timing x _0, the edge timing of the serial zero-crossing signal ZCR is varied, i.e., at the zero crossing point of the digital output D1, time is counted by the time base counter 2041 of FIG. 2 t ₀ ( No.
(Fig. 10). Note that a 1 or 0 positive / negative flag (which becomes ₀ for the minimum peak value b0) indicating whether the immediately preceding peak value is positive or negative is added to the most significant bit of the latch data. .

Further, the zero-cross time acquisition circuit 204 outputs an interrupt signal INT to the MCP3 in FIG. As a result, when the interrupt signal INT is generated, the peak value capturing circuit 203 shown in FIG. 2 holds the minimum peak value b ₀ (absolute value), and the zero-cross time capturing circuit 204 stores the minimum peak value b _0. The zero-crossing time including the positive / negative flag immediately after the occurrence of is generated is latched.

Then, after outputting the interrupt signal INT, MCP3 in FIG.
From the accesses made through the address decoder 4 (described later), the zero-crossing time and a minimum peak value b ₀ containing the negative flag is transferred to MPC3 through the bus BUS. Since the above processing is time-division-processed for six strings, as described later, before the output of the above-mentioned information, information indicating which string number the interrupt has occurred is taken as a zero-crossing time. Output from the embedding circuit 204 to the MCP3.

Next, in the peak detection circuit 201 of FIG. 2, an internal peak hold circuit (not shown) peak-holds the minimum peak value b ₀ (absolute value) of FIG. Outputs ₀ . Thus, the peak detection circuit 201 as a threshold for the peak hold signal (absolute value), the timing x ₂ whose absolute value for the negative side exceeds the threshold value of the digital output D1, minimum peak value detected again Set signal MIN to high level.

Thus, in the same manner as the second in peak value acquisition circuit 203 of Figure, the minimum peak value detection signal MIN following minimum peak value b ₁ at a timing x ₃ immediately after the high level (absolute value ) is held in a second view of the zero-crossing time acquisition circuit 204, the zero-crossing time t ₂ that includes the minimum peak value b ₁ of the immediately following generation negative flag (0 Again) is latched, sends the interrupt signal INT Later, it is transferred to MCP3.

Based on the above, the minimum peak value b ₀ ~b ₃ (absolute value) with respect to the negative side of the digital output D1 of FIG. 10, the zero-crossing time
_{t 0, t 2, t 4} , t 6 detects such, and the peak hold signal q ₀ to q ₃
Output operation in exactly the same manner etc., the detection of such a maximum peak value a ₀ ~a ₃ with respect to the positive side of the digital output D1, zero-crossing time _{t 1, t 3, t 5} , t 7 the detection of such, and peak Hold signals p _{0 to} p
Output operations such as ₃ are performed in parallel. In this case, the maximum peak value detection signal MAX is output from the peak detection circuit 201 as shown in FIG. 10, and the peak value capturing circuit shown in FIG.
In the 203 and the zero-cross time acquisition circuit 204, the zero-cross times t ₁ and t ₃ including the maximum peak values a _{0 to} a _{3 and the} like and the positive / negative flag (in this case, 1 because it is a positive peak) based on the signal MAX. , t ₅ , t _{7 and the} like are latched.

The operation shown above, from the second view of the zero-crossing time acquisition circuit 204, an interrupt signal INT for each time of a 10 view of the zero-crossing time t ₀ ~t ₇ is output to MCP3 of Figure 1,
At each time based on this, as a set of the minimum or maximum peak value (absolute value) and the zero crossing time, b ₀ and t ₀ , a ₀ and t ₁ ,
b ₁ and t _2, a ₁ and t _3, · · · and the like are sequentially output to MCP3. Here, in MCP3, the determination as to whether the peak value is the minimum peak value (negative peak value) or the maximum peak value (positive peak value) is made by the positive / negative flag added to the most significant bit of the zero crossing time. It is possible.

In addition to the above operation, the peak value capturing circuit 203 shown in FIG.
Can arbitrarily output the instantaneous value of the digital output D1 by accessing from the MCP3. This will be described later.

Further, the peak hold signals p ₀ to p _{0 of} FIG. 10 generated by the peak hold circuit in the peak detection circuit 201 of FIG.
Each of the decay rates (time constants) such as p ₃ , q _{0 to} q _{3 and the} like is changed as needed by the time constant conversion control circuit 202 in FIG. 2 under the control of the MCP ₃ .

Basically, the time constant is changed so that the peak hold signal is rapidly attenuated after, for example, one pitch cycle time of the digital output D1 has elapsed. The pitch period information at this time is set by the MCP3 in FIG. 1 after extracting each pitch period by the operation described later.
, The pitch period information is set in a time constant conversion register CHTRR (described later) in the time constant conversion control circuit 202. Accordingly, the time constant conversion control circuit 202 includes a string independent counter (not shown) provided inside,
From P3, a match is made with the pitch cycle information set in the time constant conversion register CHTRR, and a time constant change signal is sent to the peak detection circuit 201 when a match output occurs after the pitch cycle period has elapsed. With this operation, the peak hold signal rapidly attenuates after the elapse of one pitch period, whereby the peak of the next pitch period is appropriately detected.

Before the elapse of one pitch period, the peak detection circuit
At 201, the next maximum or minimum peak value detection signal MAX or
When MIN is detected, the counter is reset at the timing of the fall of these signals to generate the next peak hold signal.

In addition, since the vibration cycle of each string varies widely depending on the position where the player presses the string on the fret, at the time of the rising of the waveform corresponding to each string of the digital output D1,
In order to quickly detect the vibration of the waveform, the peak hold signal rapidly attenuates when the maximum sound period of each string elapses, and immediately thereafter, the open string period of each string so as not to pick up harmonics of each pitch period. (Minimum sound period) The setting is performed so that the sound attenuates rapidly with the passage of time. Then, after the pitch cycle is effectively extracted, the setting is made so as to rapidly attenuate as the pitch cycle time elapses, and follows the change in the pitch cycle of each string of the digital output D1 due to the performance operation.

Further, in the pitch detection circuit 201, which of the positive and negative peak values is to be controlled for the peak hold is determined by
The determination is made based on whether the serial zero-cross signal ZCR is at a high level or a low level.
See figure).

<< Operation of Central Control Unit (MCP) >> By the above operation, the maximum or minimum peak value, the zero crossing time, and the positive / negative flag indicating the positive / negative of the peak value are supplied from the pitch extracting circuit 2 in FIG. The MCP 3 shown in FIG. 1 generates musical tone control information for controlling the musical tone generating circuit 501 by extracting pitch and extracting parameters relating to volume and timbre. MCP3 is ROM301
In accordance with the program stored in FIG. 3, the operation flowcharts shown in FIGS. 3 to 9A to 9E are executed as described in detail below.

(Explanation of Variables) First, the variables used in the control programs shown in the operation flowcharts of FIGS. 3 to 9A to 9E to be described later are listed below.

AD: input peak value (instantaneous value) directly reading the input waveform D1 to the pitch extraction digital circuit 2 in FIG. 1 AMP (0, 1): positive or negative previous (old) peak value (old) AMRL1... It is the previous amplitude value (peak value) for checking relative (off) off stored in the amplitude register. Here, the relative off is equivalent to a silencing process when the fret operation is stopped and the sound is shifted to an open string by canceling the sound based on a sudden decrease in the peak value.

AMRL2... The amplitude value (peak value) of the last two times for the relative-off stored in the amplitude register, to which the value of AMRL1 is input.

CHTIM: The cycle corresponding to the highest value fret (22nd fret) CHTIO: The cycle corresponding to the open string fret CHTRR: The time constant conversion register, and the time constant conversion control circuit 202 described above (FIG. 2) It is provided inside.

DUB: a flag indicating that the waveforms continuously came in the same direction, FOFR: a relative off counter, HNC: a waveform number counter MT: a flag from which the pitch is to be extracted (positive =
1, negative = 0) NCHLV: No change level (constant) OFTIM: Off time (e.g., corresponding to the open string cycle of the string) OFPT: Normal off check start flag ONF: Note on flag RIV ... Flag for switching the processing route in step (STEP) 4 described later ROFCT ... Constant that determines the number of relative off checks STEP: Registers (1 to 1) that specify the flow operation of MCP3
5) TF: Previous zero-cross time data that became valid TFN (0, 1): Previous zero-cross time data immediately after positive or negative peak value TFR: Time storage register THLIM・ ・ Frequency upper limit (constant) TLLIM ・ ・ ・ Frequency lower sine (constant) TP (0,1) ・ ・ ・ Positive or negative previous period data TRLAB (0,1) ・ ・ ・ Positive or negative absolute trigger level ( Note-on threshold value) TRLRL: Relativistic on (re-start) threshold TRLRS: Resonance removal threshold TTLIM: Lower frequency limit at trigger TTP: Previously extracted period data TTR・ ・ ・ Period register, TTU ・ ・ ・ Constant (product of 17/32 and current cycle information tt) TTW ・ ・ ・ Constant (product of 31/16 and current cycle information tt) TX ・ ・ ・ Pitch for pitch change Period register VEL: Information that determines the speed (velocity), the maximum peak of the waveform at the start of sound generation Determined at.

X: a flag indicating the normal state or more b: the current positive / negative flag stored in the working register B (1 at the next zero point after the positive peak, 0 at the next zero point after the negative peak) c ······························································································································································ Extracted cycle data ottp ... Pitch cycle register for previous pitch change t ... Current zero-cross time stored in working register T0 tt ... Current cycle information stored in working register TOTO (interrupt Operation of Processing Routine) Next, FIG.
3 is a diagram showing an operation flowchart of an interrupt processing routine showing a process when an interrupt is issued by an interrupt signal INT from a zero-cross time acquisition circuit 204 (FIG. 2).

As described above, at the time when the interrupt signal INT is output from the zero-crossing time capturing circuit 204, the maximum or minimum peak value (absolute value) is held in the peak value capturing circuit 203 in FIG. The acquisition circuit 204 latches a zero-crossing time immediately after the occurrence of the peak value, and a positive / negative flag indicating 1 when the immediately preceding peak value is the maximum (positive) peak value and 0 when the immediately preceding peak value is the minimum (negative) peak value. Have been.

Therefore, MCP3 first sets a predetermined address read signal AR in the address decoder 4 in I1 of FIG.
A string number read signal ▼ is output to the zero cross time acquisition circuit 204 in FIG. As a result, from the circuit 204, the string number indicating which string number the interrupt has occurred is first sent to the MCP via the bus BUS.
Output to 3. Subsequently, the MCP 3 sets another address read signal AR of the address decoder 4 and sends the time read signal ▲ to the zero-cross time read circuit 204.
A signal corresponding to the string number among ▼ to ▲ ▼ is output. As a result, from the circuit 204, the zero-crossing time information set in the latch corresponding to the string number specified by the time reading signal （(i = 1 to 6) is transmitted via the bus BUS to the MCP3. Is output to This is defined as the current zero-cross time t as shown in FIG. 3 I1.

Subsequently, in FIG. 3 I2, the positive / negative flag added to the most significant bit of the zero-crossing time information is taken out and set as the current positive / negative flag b, as described in the section “Operation of the pitch extraction digital circuit”. .

Thereafter, at I3 in FIG. 3, the MCP 3 is transmitted via the address decoder 4 in the same manner as described above to the peak value capturing circuit 20 in FIG.
For 3, the peak value read signal ▲ ▼ (j =
1 to 12) is output. Here, the same circuit
Although not shown, there are 12 latches in the 203 that hold the maximum peak value and the minimum peak value for 6 strings, so that the MCP3 determines the string number and the positive / negative flag b based on the string number and the positive / negative flag b.
Select and output the peak value read signal ▲ ▼. As a result, from the circuit 203, the maximum peak value or the minimum peak value (absolute value) set in the latch designated by the peak value read signal ▲ ▼
Is output to the MCP3 via the bus BUS. This is shown in Fig. 3 I
As shown in FIG. 3, the current peak value is c.

After the above operation, the values of t, c, b obtained as described above are set in registers T0, C, B (not shown) in MCP3 at I4 in FIG. Each time the above interrupt processing is performed, this register stores such zero-crossing time information,
The peak value information (absolute value) and the information of the positive / negative flag indicating the type of the peak are written as one set, and the main routine described later processes the information for each string.

Note that there are six registers T0, C, and B corresponding to six strings, and the tone control processing described below with reference to FIGS. 4 to 9 is performed in a time-division manner for all six strings. Hereinafter, the processing for one string will be described for simplicity.

(Operation of Main Routine) FIG. 4 is an operation flowchart showing the operation of the main routine. Here, initialization after power-on (initialization), note-off (silence) processing of music, and STEP
A process of selecting each process from 0 to STEP 4 (or 5) is performed. In the present embodiment, the processing of the musical tone control is performed by a processing concept of a step as described later, and as described later, STEP0 → S
Tone control is performed in the order of TEP1, STEP2, STEP3, STEP4 (→ STEP5), and STEP0.

<< Basic Operation >> In FIG. 4, first, when power is turned on (power is turned on), various registers and flags are initialized in M1, and the register STEP is set to 0. In this case, as described in the description of the time constant conversion control circuit 202 (FIG. 2) in the section "Operation of the pitch extraction digital circuit", the peak detection circuit 201 (the second
MCP3 sets the highest tone fret cycle CHTIM to the time constant conversion register CHTRR in the time constant conversion control circuit 202 via the bus BUS so that the waveform at the rising edge of the waveform of the digital output D1 can be quickly detected. , Peak detection circuit 201
Peak hold signal outputted from the peak hold circuit of the inner (FIG. 10 p ₀ or q _0, etc.) is controlled to rapidly attenuated at the highest sound period time.

Subsequently, at M2 in FIG. 4, it is determined whether or not the register described in the section "Operation of the interrupt processing routine" is empty. If NO (hereinafter referred to as NO), the process proceeds to M3, and each register B , C, T0 are read. Subsequently, in M4, it is determined when the value of the register STEP is, and the processing of STEP0 is performed in M5, the processing of STEP1 is performed in M6, the processing of STEP2 is performed in M7, the processing of STEP3 is performed in M8, and the processing of STEP4 is performed in M9. The update to the next step is performed in the processing of STEP0 to STEP4 as described later.

<< Note-off operation >> When the buffer is empty in M2, that is, when the buffer is empty (hereinafter, referred to as YES), the process proceeds to M0 to M19, where the normal note-off algorithm is performed. This note-off algorithm uses a digital output
In D1 (FIG. 1), the note-off algorithm is performed when the peak value is equal to or less than the off (OFF) level for a predetermined off-time period.

First, it is determined in M10 whether or not STEP = 0, and in the case of YES, note-off does not need to be performed because the tone is in an initial state, and the process returns to M2. On the other hand, in the case of NO,
Proceed to M11.

In M11, the input peak value (instantaneous value) AD of the digital output D1 at that time is directly read. This is because the MCP 3 receives the peak value capturing circuit 203 via the address decoder 4 (FIG. 2).
To read peak value ▲ ▼ ~ ▲
By providing any of the above, the circuit 203 can achieve this by outputting the current instantaneous value of the digital output D1 to the MCP3 via the bus BUS. Then, it is determined whether or not this value AD is equal to or less than a preset off level. If NO, the process returns to M2 because there is no need to perform note-off, and if YES, the process proceeds to M12.

In M12, it is determined whether or not the previous input peak value AD is equal to or less than the off level. If NO, the process proceeds to M17, starts the timer 303 in the MCP3, and returns to M2. Then, the next time the process comes again, since M12 becomes YES, the process proceeds to M13, where it is determined whether the value of the timer 303 is the off-time OFTIM. For example, the open string flat period CHTIO of the string being processed is set as the off time OFTIM, and if NO in M13, the process returns to M2 and the process is repeated, and Y
When it reaches ES, the process proceeds to M14, where 0 is written to the register STEP,
After setting the maximum tone freight period CHTIM in the time constant conversion register CHTRR, the process proceeds to M16 via M15 (described later).
That is, when the register of the digital output D1 is attenuated, the input peak value AD which is equal to or less than the off-level becomes the off-time OFTI.
If the time corresponding to M continues, it can be determined that the string is no longer played because the digital output D1 is not input, and the process proceeds to M16 to perform note-off processing.

In M16, MCP3 is used for the tone generator 501 (Fig. 1).
A note-off instruction is transmitted, thereby stopping the tone generation. If you take notes off like this,
Return to STEP0.

In step M15, a determination of YES is made in a normal state. However, the register STEP may take a value other than 0 even when the tone generation is not instructed by the processing described later ( In such a case, for example, due to the input of noise), in such a case, the process returns to M2 after the processes of M14 and M15, thereby being initialized to STEP0.

(Processing Operation of STEP 0) Next, details of each routine that branches and performs corresponding processing in the main routine of FIG. 4 will be described.

First, FIG. 5 is an operation flowchart of the process of step 0 (STEP0) shown as M5 in the main routine of FIG. In this processing, initialization for pitch extraction processing and the like, and processing for transition to the next STEP 1 are performed. Hereinafter, description will be made with reference to the basic operation explanatory diagram of FIG. In addition,
FIG. 11 shows the same waveform as FIG.

<< Basic Operation >> Now, the main routine of FIG. 4 is performed by repeating the loop of M2 and M10 to execute the “operation of the interrupt processing routine”.
As described in the above section, the interrupt is issued from the pitch extraction digital circuit 2 (FIG. 1) and the registers T0,
Waiting for data to be input to C and B.

Then, when data is input and the contents of the above registers are read from M2 to M3 in FIG. 4, M5, M5,
That is, the process proceeds to STEP0 in FIG. In this state, for example, as shown in FIG. 11, the current zero-cross time t = t ₀ ,
The current positive / negative flag b = 0 and the current peak value c are the minimum peak value c = b ₀ (absolute value) from b = 0. In FIG. 11, b and b _{0 to} b ₃ are different symbols.

First, in S01 of FIG. 5, the value of the current peak value c is the absolute trigger level (positive threshold value for note-on).
It is determined whether it is larger than TRLAB (b). This determination is executed for each of the positive and negative polarities (maximum peak value or minimum peak value) based on the value of the positive / negative flag b this time, and the absolute trigger level TRLAB (1) on the positive side and the absolute trigger level on the negative side The trigger level TRLAB (0) is the digital output D1
Different values can be empirically set in consideration of the case where an offset is superimposed on (FIG. 1). The same value may be used in an ideal system. In the example of FIG. 11, the current minimum peak value c = b ₀ (absolute value) and TRLAB (b) = TRLAB
(0) and c = b ₀ > TRLAB (0), that is, the determination is YES.

Next, after S02 (described later), the process of S03 is executed. Here, first, the current positive / negative flag b is written into the flag MT, 1 is written into the register STEP, and preparations are made for the transition to the next step. Zero cross time data
Set as TFN (b). In the example shown in FIG. 11, MT = b = 0, TFN (b) = TFN (0) = t = t ₀ as shown in FIG.
Becomes

Subsequently, in S04, other flags (except for the constant value) other than the above-described flags described in the section of “variable description” are initialized.

Further, in S05, the current peak value c is set as the previous peak value AMP (b) (absolute value) for the subsequent processing, and the process returns to the main routine M2 in FIG.
In the example of FIG. 11, AMP (b) = AMP as shown in FIG.
(0) = a c = b _0.

By the above processing, the example of FIG. 11 (STEP0 →
This negative flag b = 0 in the register B flag MT as shown in the 1 between) is written, the current zero-crossing time data t = t ₀ of the register T0 data of the previous zero-crossing time of the negative side TFN (0) Is written and the previous negative peak value
AMP (0) to the minimum peak value c = b ₀ This register C is written.

<< Resonance Elimination Operation >> When the value of the current peak value c is equal to or lower than the absolute trigger level TRLAB (b) in S01 of FIG. Simply setting the value of the current peak value c to the peak value AMP (b) returns to the main routine of FIG. However, when picking one string causes another string to resonate, the vibration level of the other string gradually increases, and the determination result of S01 in FIG. 5 eventually becomes YES. Then, the process proceeds to S02. However, in such a case, since normal picking is not performed, it is not appropriate to shift to a sounding (note-on) operation. So, S0
In the process 2, the above-mentioned resonance is removed. That is, in the above case, the current peak value c is equal to the previous peak value AMP.
Since the difference c-AMP (b) is not larger than the resonance elimination threshold value TLRRS, it is determined that the resonance state has occurred, and the sound generation process is not started. Without shifting, the previous peak value AMP in S05
By setting the value of the current peak value c in (b), the fourth
It returns to the main routine of the figure. On the other hand, when normal picking as shown in FIG. 11 is performed, the waveform suddenly rises, and the difference c-AMP (b) between the peak values exceeds the resonance removal threshold value TRLRS. The process moves from S02 to S03.

<< Relative-On Entry Operation >> In FIG. 5, A is a relative-on (reproduction start) entry to be described later, and jumps to S06 from a flow of STEP 4 to be described later. Then, in S06, the musical tone output so far is once erased (note off), and the process proceeds to S03 to start re-sounding. The process for starting re-sound generation is the same as that for starting normal sound generation, and is as described above. Here, note-off processing in S06 is the fourth
This is the same as the process of M16 in the figure.

(Processing Operation of STEP1) Next, FIG. 6 is an operation flowchart of the processing of Step 1 (STEP1) shown as M6 of the main routine of FIG. In this processing, initialization such as pitch extraction processing subsequent to STEP 0 and transition processing to STEP 2 subsequent thereto, or double processing (error processing) when a strange waveform is input is performed.

<< Basic Operation >> First, after the initial setting for the first data is performed in STEP0, in the main routine of FIG.
Due to the repetition of the loop of M10 → M11 → M2, the pitch extraction digital circuit 2 (FIG. 1) interrupts again and waits for the next data to be input to the registers T0, C and B.

Then, when data is input and the contents of the above registers are read via M2 to M3 in FIG. 4, M6, M6,
That is, the process proceeds to STEP 1 in FIG. In this state, for example, as shown in FIG. 11, the current zero-cross time t = t ₁ ,
The current positive / negative flag b = 1, and the current peak value is the maximum peak value c = a ₀ from b = 1.

First, through S11 in FIG. 6 (described later), in S12, the value of the current peak value c is set to be exactly the same as described in the description of S01 in FIG. ,
It is determined whether or not the level is higher than the absolute trigger level TRLAB (b). In the example of FIG. 11, the maximum peak value c = a ₀ this time and TR
LAB (b) = TRLAB (1) is compared and c = a ₀ > TRLAB
(1), that is, the determination is YES.

Next, in step S13, 2 is written into the register STEP, and preparations are made for shifting to the next step.

Subsequently, in S14, the current zero-cross time t in the register T0 is set as the previous zero-cross time data TFN (b) for the subsequent processing. Further, in S15,
The current peak value c of the register c is set as the previous peak value AMP (b) for the subsequent processing, and the process returns to the main routine M2 in FIG. In the example of FIG. 11, TFN (1) = t = t ₁ and AMP (1) = c = a ₀ as shown in FIG. The contents of the MT are not rewritten and remain at 0.

<< Operation of Dubbing Processing >> When the normal digital output D1 as shown in FIG. 11 is input, the minimum (large) on the negative (positive) side in STEP0 is described.
After the peak value (absolute value) is extracted, the maximum (small) peak value on the positive (negative) side is extracted in STEP1.
Therefore, in S11 of FIG. 6, the positive / negative flag b =
Since 1 (0) is different from the flag MT = 0 (1) set in STEP0, the process proceeds to S12 as described above.

However, in some cases, a waveform as shown in FIG. 12 (a) or (b) may be input in STEP1 after STEP0. In this case, after the minimum peak value b ₀ of the negative side it is extracted with STEP0, the minimum peak value b ₁ again negative in STEP1 is extracted I dub. Therefore, in S11 of FIG. 6, the positive / negative flag this time becomes b = 0, and the flag M set in STEP0 is set.
Matches T = 0. In this case, the process proceeds to S16 of FIG. 6, and the double processing (error processing) is performed.

In S16, it is determined whether the value of the peak value c is larger than the previous peak value AMP (b) of the same sign.

Now, in the case of FIG. 12 (a), c = b ₁ > AMP (b)
= AMP (0) = b ₀ does not hold. In such a case, the minimum peak value b ₁ of this ignores a funny waveform (hatched portion), STEP is not updated, the main routine of FIG. 4 M2
Return to the process of and wait for the next normal peak to be input.

On the other hand, in the case as shown in FIG. 12 (b), c = b ₁ > AMP
(B) = AMP (0) = b ₀ holds. In such cases, ignoring the direction of the minimum peak value b ₀ extracted with previous STEP0 as strange waveform (hatched portion), the previous zero-crossing time data of negative side is set in STEP0 TFN
The contents of (0) and the previous peak value AMP (0) on the negative side are changed by replacing the current zero crossing time t and the current peak value c with S14 and S15 in FIG. That is, in the example of FIG. 12B, TFN (0) = t = t ₁ and AMP (0) = c =
b becomes ₁ . After this doubling process, the STEP is not updated (not through S13 in FIG. 6), and the M2 of the main routine in FIG.
Return to the process of and wait for the next normal peak to be input.

After the operation, entering the normal peak value, the sixth processing the by S11 → S12 → S13 → S14 → S15 in Figure is made, for example, t = t ₁ as shown in FIG. 11, the following The transition to the processing of STEP2 is performed.

(Processing Operation of STEP 2) Next, FIG. 7 is an operation flowchart of the processing of Step 2 (STEP 2) shown as M7 in the main routine of FIG. In this process, the first for the pitch extraction
Detection of the second pitch period, velocity setting, and ST
Performs transition to EP3 or error processing (doubble processing) when a strange waveform is input.

<< Basic Operation >> First, after the processing in STEP 1 described above, in the main routine of FIG. 4, the pitch extraction digital circuit 2 (FIG. 1) is repeated by repeating a loop of M2 → M10 → M11 → M2.
Again, and waits for the next data of the registers T0, C, and B to be input.

Then, when data is input and the contents of the above registers are read through M2 to M3 in FIG. 4, M7, M7,
That is, the process proceeds to STEP 2 in FIG. In this state, for example, as shown in FIG. 11, the current zero-crossing time t = t ₂ ,
This negative flag b = 0, the current peak value is c = b ₁ at the minimum peak value than b = 0.

First, in S21 after S20 in FIG. 7 (described later), the MCP 3 is currently processing the time constant conversion register CHTRR in the time constant conversion control circuit 202 in FIG. 2 via the bus BUS. Set the open string fret cycle CHTIO of the string. This is because, as described in the explanation of the next constant conversion control circuit 202 in the section “Operation of the pitch extraction digital circuit”, the peak detection circuit 201 (FIG. 2) detects the oscillation at the rising of the waveform of the digital output D1. After the detection, the peak hold signal (FIG. 10) output from the peak hold circuit in the peak detection circuit 201 so as not to pick up the overtone of each pitch cycle.
p ₁ , q ₂ etc.) is the open string period of each string, that is, the lowest sound period CHTIO
Rapidly attenuates as time elapses.

Next, in S22, it is determined whether or not the value of the current peak value c is greater than 7/8 times the previous peak value AMP (b) of the same sign. Although this processing will be described in detail later, usually, the waveform obtained by picking the strings smoothly attenuates smoothly, so this determination is YES, and the processing proceeds to S2 (described later) through the next S23.
Proceed to 4.

In S24, the first pitch period is detected by calculating {(current zero-cross time t)-(previous zero-cross time data TFN (b) of the same sign)}. Then, in order to use this result as a condition for note-on (start of sound generation) in STEP 3 described later, the previous cycle data TP
Set as (b). In the example of Figure 11, the TP (0) = t-TFN (0) = t 2 -t 0 as shown in FIG.

In S24, the current zero-cross time t is set as the previous zero-cross time data TFN (b) for the subsequent processing. In the example of FIG. 11, as shown in FIG.
(P) = t = t ₂ . The TFN installed in STEP0
(0) = t ₀ is the previous cycle data TP (b) = TP (0)
Is no longer needed because it can be calculated and is deleted.

Similarly, in S24, 3 is written in the register STEP, and preparation for transition to the next STEP is made.

Further, in S24, the largest value among the current peak value c and the previous peak values AMP (0) and AMP (1) is set as the velocity VEL for the subsequent processing. It should be noted that the velocity VEL is used as a value for determining the volume of a musical tone as described later in STEP3. Similarly, the current peak value c is set as the previous peak value AMP (b), and the process returns to the process of M2 in the main routine of FIG. In the example of FIG. 11,
VEL = max ｛c, AMP (0), AMP (1)｝ = max ｛b ₁ ,
b ₀ , a ₀ }, and AMP (0) = c = b ₁ . In addition, STE
AMP (0) = b ₀ set in P0 is unnecessary and is deleted because the velocity VEL can be calculated.

<< Operation of Dubble Processing >> When a normal digital output D1 as shown in FIG. 11 is input, the maximum (small) on the positive (negative) side in STEP1 described above.
After the peak value is extracted, the minimum (large) peak value on the negative (positive) side is extracted in STEP2. Therefore,
In this case, the sign of the peak value in STEP2 is opposite to that in STEP1, and is the same as that in STEP0. In S20 in FIG. 7, the positive / negative flag b = 0 (1) is set to STEP0 in this case.
Coincides with the flag MT = 0 (1) set in the step (1), and proceeds to S21 as described above.

However, in the same manner as described in the description of the “operation of the dub processing” of the “processing operation of STEP 1”, the waveform sometimes doubles, and after STEP 1, the waveform as shown in FIG. 13A or 13B is obtained. May be entered. In this case, ST
After the maximum peak value a ₀ of the positive side is extracted in EP1, the maximum peak value a ₁ again positive in STEP2 is extracted it dubs. Therefore, in S20 of FIG. 7, the current positive / negative flag is b = 1.
And matches the flag MT = 0 set in STEP0. In this case, the process proceeds to S25 in FIG. 7, and the double processing (error processing) is performed. 13A and 13B, the hatched peaks indicated by simple hatching are the peak hold signals p _{0 in} FIG. 13A or 13B generated from the peak hold circuit in the peak detection circuit 201 in FIG. , P ₁ , q _0, etc., and were not detected as peaks.

In S25, first, the doubling flag DUB is set to 1 (described later), and the process proceeds to S26, where it is determined whether or not the value of the current peak value c is larger than the previous peak value AMP (b) of the same sign.

Now, in FIG. _{13A, STEP0 (t = t 0)} , STEP1 (t
= T ₁ ), when STEP 2 is executed at t = t ₂ , c = a ₁ > AMP (b) = AMP (1) = a ₀ does not hold. That is, the determination result of S26 in FIG. 7 is NO. In such cases, the maximum peak value a ₁ of this ignores a funny waveform (areas in a cross hatched hatch in the figure),
The STEP returns to the processing of M2 in the main routine of FIG. 4 without updating, and waits for the next input of a normal peak. At t = t _3, by the minimum peak value c = b ₁ is inputted, S20 of FIG. 7 becomes YES, and as in the case of FIG. 11, the S21 → S22 → S23 → S24 Processing is performed and the thirteenth
In t = t ₃ A Figure proceeds to the process in next STEP3. In addition, in FIG.
The previous cycle data TP (0) set in S24 is
As shown in Figure 3A, the current zero-crossing time t _3, STEP0
Made to the difference between the previous zero-crossing time t _0, which is set in. The starting point of the next periodic data Tx calculated in STEP 3 to be described later, since the cross hatched peak (c = a ₁ ) is ignored as shown in FIG.
Previous zero crossing time TFN set in EP1 (1)
= Is t _1.

On the other hand, in the case of FIG. 13B, c = a ₁ > AMP
(B) = AMP (1) = a ₀ does not hold. That is, S in FIG.
The determination result of 26 is YES. In such a case, the previous S
Ignore towards maximum peak value a ₀ extracted with TEP1 as strange waveform (areas in a cross hatched hatch in the figure),
The contents of the previous zero-cross time data TFN (1) set in STEP 1 and the previous peak value AMP (1) on the positive side are replaced with the current zero-cross time t and the current peak value c by S29 in FIG. Change. That is, 13B
In the example of the figure, as shown in the figure, TFN (1) = t = t ₂ , AMP
(1) = c = a ₀ After the dubbing process, the STEP returns to the process of M2 in the main routine of FIG. 4 without updating, and waits for the next normal peak value to be input. Hereinafter, processing after minimum peak value c = b ₁ is inputted in t = t ₃ is the same as in the FIG. 13A. However, the peaks extracted in STEP 1 (peaks c = a ₀ hatched by cross hatching in FIG. 13B) are ignored, and the peaks are changed to c = a ₁ , so that they are calculated in STEP 3 described later. TP
(0) of the origin of the next period data T _y is the last zero crossing time TFN set in the doubling process STEP2
(1) = t ₂ , which is different from the case of FIG. 13A.

As described above, when the waveform is doubled as shown in FIG. 13A or FIG. 13B, the peak having the smaller peak value is ignored as a strange waveform, and error processing is performed.

Next, a description will be given of the branch of S22 in FIG. 7 for the other case of the doubling processing.

Now, when the processing of STEP 2 in FIG. 7 is executed, the normal waveform obtained by picking the strings attenuates smoothly and naturally, so that the value of the current peak value is equal to the value of the previous peak value AMP (b) of the same sign in S22. The value becomes greater than 7/8, the determination in S22 is YES, and the process proceeds to the next S23.

However, in some cases, c> (7/8) × AMP (b) may not be satisfied. In the first case, for example, by picking a string near the bridge, the waveform may not be a normal but smooth attenuation waveform, and the determination result in S22 may be NO. However, even in such a case, the processing of S24 in FIG. 7 needs to be performed normally. In this case, since the waveform is normal, the above-mentioned double does not occur, and the seventh is performed before that.
Since it does not branch from S20 to S25 in the figure, the double flag DU
The value of B remains at 0. Therefore, if DUB = 1 does not hold in S27 of FIG. 7, the process returns to the process of S24 again, regardless of the determination result of S22, and performs the process described in the above-mentioned "basic operation". It should be noted that the value of the double flag DUB has been initialized to 0 in the processing of S04 in STEP0 of FIG.

On the other hand, as a second case where S22 in FIG. 7 is not satisfied,
The above-mentioned doubles may occur in the waveform. This case will be described below with reference to FIG. 13C.

Now, in the same way as described in FIG. 13B, as shown in 13C _{view, STEP0 (t = t 0)} , after treatment STEP1 (t = t _1), said doubling processing at t = t ₂ is performed, the peak of c = a ₀ (peak subjected to cross-hatched hatch in the figure) is removed, and c = a ₁ peak (peak hatched vertical bars in the figure) is left . It should be noted that the peak (c = a ₁ ) hatched with a simple diagonal line is a peak that is not originally detected, as in FIG. 13A or 13B.

When doubling as described above occurs, the positive and negative flags as in the next t = t ₃ shown in 13C diagram for the b = 0, coincides with the flag MT = 0 which is set in STEP0. Therefore, the process proceeds from S20 to S22 through S21 in FIG.
However, the minimum peak value c = b ₁ of this detected at t = t _3, the waveform is considerably away from the previous minimum peak value AMP (0) of = b ₀ with the same sign for the mapped twice, greater attenuation . Therefore, as shown in FIG. 13C, S22 in FIG.
May be NO.

If as described above, because a duplication process in earlier t = t _2, the value of Daburifuragu DUB is 1. Therefore, the determination result of S27 in FIG. 7 is NO, and S28
Then, the process proceeds to S29 (to be described later).

In S29, the 13C view of t = to redo the acquired newly processed normal waveform t ₃ after, set in STEP0 the previous zero-crossing time data TFN (0),
Then, the content of the previous peak value AMP (0) on the negative side is changed by replacing the current zero crossing time t and the current peak value c with S29 in FIG. That is, in the example of FIG. 13C,
As shown in the figure, TFN (0) = t = t ₃ , AMP (0) = c =
b _1, and the end, the peak subjected to horizontal hatch in FIG (c = b ₀₎ are ignored. In addition, for the following processing,
The double flag DUB is reset to 0 in S28 of FIG.
After these operations, the process returns to M2 of the main routine in FIG. 4 without updating the value of STEP, and waits for the input of the next peak.

Then, in the above case, as shown in FIG. 13C, t = t ₄ ,
In t = t _5, after the STEP2 of Figure 7 was repeated, STE
Move to P3. Since there are various patterns for such a repetition operation of STEP2, a detailed description thereof will be omitted, but a normal waveform can be obtained as a whole flow, and data TFN to be used in the next STEP3 is obtained.
After operating such that (0), AMP (0), TFN (1), and AMP (1) are effectively determined, the process proceeds to STEP3.
In the first 13C view of a _{case, TP (0) = t 5} -t 3, the starting point of the next period data Ti calculated in the later-described STEP3 becomes TFN (1) = t _4.

(Processing Operation of STEP3) Next, FIG. 8 is an operation flowchart of the processing of Step 3 (STEP3) shown as M8 in the main routine of FIG. In this process, note-on (start of sound generation)
Processing, extraction of a pitch cycle for setting a pitch at the time of note-on, calculation of velocity, transition processing to STEP 4, error processing when a strange waveform is input, and the like are performed.

<< Basic Operation >> First, after the processing in step 3 is performed,
In the main routine shown in the figure, the pitch extraction digital circuit 2 (first circuit) is repeated by repeating a loop of M2 → M10 → M11 → M2.
Interrupt) again, and registers T0, C, B
Waiting for the next data to be entered.

Then, when data is input and the contents of the above registers are read via M2 to M3 in FIG. 4, M8, M8,
That is, the process proceeds to STEP 3 in FIG. In this state, for example, as shown in FIG. 11, the current zero-cross time t = t ₃ ,
This negative flag b = 1, this peak value is c = a ₁ a maximum peak value from b = 1.

First, after going through S30, S31, and S32 in FIG. 8 (described later), the velocity VEL is calculated in S33. Now, as described in the “Basic operation” section of the “processing operation of STEP 2”, in S24 of FIG.
In the example of the figure, the maximum value (absolute value) of each of b ₀ , a ₀ , and b ₁ is stored in the velocity VEL. Therefore, the eighth
In S33 of the figure, a larger one of the velocity VEL and the current peak value c is determined, and the larger one is determined.
The new velocity VEL when generating a musical tone in (Fig.).

In the example of Figure 11, from _{VEL = a 0, c = a} 1, VEL = max [a
₀ , a ₁ ] = a ₀ .

After the above operation, at S33 in FIG.
Then, in S34, which will be described later, the pitch cycle is detected by calculating {(current zero-cross time t)-(previous zero-cross time data TFN (b) of the same sign)}, and the previous cycle data is calculated. Set as TP (b). No.
In the example of Figure 11, as shown in FIG TP (1) = t ₃ becomes -t _1.

Subsequently, after S35 to S38 in FIG. 8 (described later), S3
In 9, the previous cycle data TP (b) obtained in S34 above
And the TP set in S24 of FIG.
It is determined whether or not the previous cycle data TP () having a different polarity from (b) is substantially the same. And the judgment result is
If YES, it is determined that the pitch cycle has started to be stably extracted, and after S301 (described later), a note-on (sound generation start) process is performed in S302. In the example of FIG. 11,
Previous period data _{TP (1) = t 3 -t} 1 and the previous period data TP (0) of the positive = t ₂ -t ₀ negative side, it is determined to be substantially the same, proceeds to the processing of the note-on. The case where the determination result is NO will be described later.

In the next step S302, volume information is generated based on the velocity VEL calculated in step S33 in FIG.
Based on the previous pitch cycle TP (b), corresponding pitch information is generated. The volume information and the pitch information generated by these so-called are output to the tone generator 501 via the MIDI-BUS and the interface MIDI shown in FIG. Then, in the same circuit 501, a musical tone having a volume and a pitch corresponding to the above information is generated in real time.

Since the processing in FIG. 8 is performed for each of the six strings of the guitar, the above processing is also performed independently for each of the six strings.

Along with the note-on processing, S38 and S301 in FIG.
After the parameters used in the next STEP 4 are set, the process returns to M2 of the main routine in FIG. 4 via S302, and proceeds to the next STEP 4. That is, in S38, the previous cycle data TP (b) extracted in S34 is set as the previously extracted cycle data TTP, and in S301, the previous zero-cross time data TFN () set in S24 of STEP2 in FIG. Is set in the time storage register TFR, and is set as the previous zero-crossing time data TF in which the current zero-crossing time data t becomes valid,
The waveform number counter HNC is cleared to 0 and the register S
The value of TEP is updated to 4, the note-on flag ONF is set to 2 (sound generation state), the constant TTU is set to 0 (minimum MIN), the constant TTW is set to maximum MAX, and the relative off check is performed. The previous amplitude value AMRL1 is cleared to 0. Each of these parameters will be described later in STEP4.

<< Operation when cycle is inappropriate >> In S34 of FIG. 8, the previous cycle data TP (b)
Is detected, this pitch period has a value greater than the period when the corresponding string is played at the highest fret,
It should have a value less than the open string period of the string.

Therefore, as a constant called the upper frequency limit THLIM, the pitch is determined by the highest note fret of the string currently being processed, and the pitch is 2-3
Set a pitch period on a semitone, and as a constant called frequency lower limit TTLIM, set a pitch period about 5 semitones lower than the pitch determined in the open string state of the same string, and in S36 and S37 in FIG.
It is determined whether the previous cycle data TP (b) obtained in S34 is larger than THLIM and smaller than TTLIM. If both the determination results are YES, the process proceeds to S39 and performs the above-described cycle determination process.

Here, if the determination results in S36 and S37 are NO, the previous cycle data TP (b) extracted in S34 is not an appropriate value. Therefore, in such a case, the fourth from S36 or S37
Returning to the processing of M2 in the main routine in the figure, STEP3 is repeated.

Next, in S39 of FIG. 8, the previous cycle data TP (b) obtained in S34 and the previous cycle data TP
If () is a value apart from (), there is a high possibility that the correct pitch period from which harmonics or the like have been extracted is erroneously extracted, and the pitch period is not stably extracted.
Accordingly, in such a case, the determination result in S39 is NO, and the process returns to the process of M2 in the main routine of FIG. 4 and repeats STEP3.

Here, when STEP3 by the above operation is repeated, in a normal waveform, the peak newly detected via M2 and M3 in FIG. 4 has its polarity switched alternately and the value of b is 0 and 1, Alternatingly, the value of the flag MT is alternately changed in S33 of FIG.
(B) is newly calculated, and the contents of TFN (b) are also rewritten. Therefore, the determinations in S36 and S37 are made for the most recently obtained pitch cycle, and the determination in S39 is made for the most recently obtained pitch cycle and the immediately preceding (about half cycle) opposite polarity side. And the pitch period of
When the pitch period can be stably extracted, the processing shifts to the note-on processing.

Each time, at S33 in FIG. 8, the velocity V
The EL is updated to correspond to the newly detected peak.

<< Operation of Noise Removal Process >> The process of S31 in FIG. 8 is a process for coping with a case where noise occurs at the rising portion of the waveform. Now, as shown in FIG. 14, for example, when peaks a ₀ , b ₀ , a _1, etc. due to noise are detected in STEPs ₀ , ₁ , and ₂ , the period of these noises is detected and the sound generation start is instructed Then, a strange sound is produced.

Therefore, in S31 of FIG. 8, when the continuous peak value changes greatly, it is determined that noise has occurred, and the abnormality detection flag X is set to 1, and in S35, O
By making a determination of N, note-on is prevented from occurring based on the noise portion.

Specifically, if the value obtained by dividing the current peak value c by 1/8 is smaller than the previous peak value AMP (b) of the same sign, it is determined that the value is normal and X = 0, otherwise, X = 1 And If it is determined in step S35 that X is not 0, the process returns to step M2 of the main routine in FIG.
Repeat 3. In this case, since the previous peak value AMP (b) is sequentially updated in S32 of FIG. 8, the process in S31 is performed on the most recently detected peak value and the immediately preceding peak value of the same sign. When the continuous peak value does not change significantly, the processing shifts to the note-on processing. In the example of FIG. 14, both t = t ₃ and t = t ₄
Note that since X = 1 in S31, note-on is not performed and t = t
X = 0 becomes for the first time the normal peak is determined to have entered the ₅ and note-on at t = t _5. And
In this case, the continuous pitch periods TP (b) and TP () have normal values.

<< Operation of Double Duty Processing >> The determination processing of S30 in FIG. 8 is a determination for double doubling processing. Now, when a normal waveform D1 such as FIG. 11 is entered, the positive and negative flag b = 1 this at t = t _3, the
If the flag does not match with MT = 0, the process proceeds to S31 as described above.

However, as described in the description of the “processing operation of STEP 1” or “processing operation of STEP 2” in the section “Operation of double processing”, when the waveform is doubled, the determination result of S30 in FIG. NO.

If the peak value c of the doubled peak is smaller than the peak value AMP (b) immediately before the same sign,
When the determination result in S303 in FIG. 8 is NO, the double peak is ignored, and after returning to the process of M2 in FIG.
Repeat 3. This is based on the same concept as in the case of FIG. 13A and the like.

On the other hand, when the peak value c of the doubled peak is larger, the determination result in S303 is YES, and the process proceeds to S304. Then, in S304, ignoring the immediately preceding peak, the content of AMP (b) is reset to the peak value c, the velocity VEL is recalculated using the value, and the process returns to M2 in FIG. Repeat STEP3. This is based on the same concept as in FIG. 13B and the like.

After the above processing, when a normal peak is input, the determination result of S30 becomes YES, and further, S35, S36, S37
When the determination results in steps S39 and S39 are YES, the note-on process is performed, and the tone generation starts.

(Processing operation of STEP 4) Next, FIGS. 9A to 9E show the main routine of FIG.
It is an operation | movement flowchart of the process of step 4 (STEP4) shown as M9. In this processing, pitch extraction / change processing, relative-on / relative-off processing, processing when the pitch period is inappropriate, and double processing are performed. First,
In pitch extraction / change processing, there is a route that only performs pitch extraction, and a route that actually changes the pitch.
Usually, it repeats every time a new peak is input. Here, what is particularly relevant to the present invention is the processing at the time of changing the pitch in the route.

<< Route Operation >> First, the routes shown in S40, S41, S42, and S63 to S67 will be described. In S40, the waveform number counter HNC
> 3, and in the case of YES, the process proceeds to S41. In S41,
It is determined whether or not the relative-on threshold value TRLRL <(current peak value c−previous peak value AMP (b) of the same sign). If NO, the process proceeds to S42 (if YES, the process will be described later). In S42, it is determined whether this time the positive / negative flag b = flag MT, that is, the pitch change side, and if YES, the process proceeds to S43.

By the way, in the initial state, the waveform number counter
Since HNC is 0 (see S301 in FIG. 8), NO is determined in S40 and the process proceeds to S42. For example, in the case of a waveform input as shown in FIG. 11, since b = 0 at t = t ₄ and MT = 1 (rewritten in S33 of STEP 3 in FIG. 8),
Proceed from S42 to S63.

In S63, it is determined whether or not the register RIV = 1 to check whether or not a peak having the same polarity is continuously inputted (whether the peak is doubled). If YES (if the peak is doubled) In step S68, the doubling process is performed (to be described later). In the case of NO (non-doubling), the process proceeds to S64, where the following process is performed.

That is, in S64, the current peak value c is changed to the previous peak value AMP.
(B), and the previous amplitude value AMRL1 is input to the amplitude value AMRL2 two times before for the purpose of the relative-off process (described later). At first, the content of AMRL1 is 0. (Eighth
(See S301 of STEP3 in the figure).

Further, in S64, the previous peak value AMP of the opposite sign
The larger value between () and the current peak value c is input to the previous amplitude value AMRL1. That is, the peak value of the larger value of the two positive and negative peak values in the cycle is set to the amplitude value AMRL1.

Then, in S65, it is determined whether or not the waveform number counter HNC> 8. Here, the waveform number counter (zero cross counter on the non-pitch changing side) HNC is incremented by 1 and counted up. Therefore, the waveform number counter HNC
Has an upper limit of 9. Then, the process proceeds to S67 after the process of S65 or S66.

In S67, the register RIV is set to 1, the content of the time storage register TFR is subtracted from the current zero crossing time t, and the result is input to the period register TTR. This cycle register TTR is
In the example of the figure, the period information TTR = t−TFR = t ₄ −t ₂ is shown. The current zero-crossing time t is stored in the time storage register TFR.
Then, the process returns to the process of M2 in the main routine of FIG.

As described above, the route is subjected to the following processing according to the example of FIG. That is, MT = 1 ≠ b, RIV =
0, AMP (0) ← c = b ₂ , AMRL2 ← AMRL1 = 0, AMRL1 ← ma
x {AMP (1) = a ₁ , c = b ₂ (whichever is greater)},
NCH ← {HNC + 1} = 1, RIV ← 1, TTR ← {t-TFR} =
{T ₄ −t ₂ }, and TFR ← t = t ₄ . Therefore, the previous zero-cross point of the same polarity t = t ₂ (STEP 2 → 3
The difference that is the variation time) of time information to the current zero cross point t = t _4, so that the cycle information is Motoma'. Then, the process returns to the process of M2 in the main routine of FIG. 4, and waits for the input of the next peak.

<< Route Operation >> Next, a description will be given of a case where the vehicle has proceeded to the route shown in S40 to S62. Now, since the waveform number counter HNC is 1, (S
66, and proceeds from S40 to S42 (S40 will be described later).

In S42, for example, in the case of FIG. 11, MT = 1, b =
Since it is 1, it becomes YES and proceeds to S43.

In S43, it is determined whether or not the register RIV = 1. Already in the route, the register RIV is set to 1 (S
67)), so the determination in S43 is YES, and the process proceeds to S44. It should be noted that the dubbing process performed when the determination result of S43 is NO will be described later.

In S44, it is determined whether or not the register STEP = 4, and YES
In the case of, the process proceeds to S45 (the case of NO will be described later). In S45, it is determined whether or not the current peak value is c <60H (H indicates a hexadecimal notation). If a peak value having a large value is input, the determination result is NO, and the process proceeds to S47.
On the other hand, if the value is smaller than 60H, the result is YES and S46
Proceed to.

In S46, it is determined whether or not the amplitude value (peak value) AMRL2 of the previous time AMRL2−the previous amplitude value (peak value) AMRL1 ≦ (1/32) × the amplitude value (peak value) of the previous time AMRL2 (in the case of YES).
Proceeding to S47, the relative off counter FOFR is set to 0. In the case of NO, the process proceeds to S74 and the relative off process is performed. The relative off processing will be described later.

In S48, a period calculation is performed. Specifically, (current zero-cross time t-previous zero-cross time data TF)
Is set in the register TOTO as the current cycle information tt. Then, the process proceeds to S49.

In S49, it is determined whether or not this cycle information tt> frequency upper limit THLIM (upper limit after the start of sound generation), and if YES, S50
(The case of NO will be described later.) S49 frequency upper limit THLIM
Is the upper limit of the allowable frequency range at the time of triggering (at the start of sound generation) used in S36 of STEP 3 in FIG. 8 (therefore, the period is the minimum and corresponds to the pitch period two to three semitones above the highest note fret) Is the same as

Next, the following processing is performed in S50. That is, the register RIV is set to 0, the current zero-cross time t is input as the previous zero-cross time data TF, the previous peak value AMP (b) is input as the peak value e twice before, and the current peak value c is set as the previous peak value c. It is input to the peak value AMP (b).

Then, after the process of S50, the process proceeds to S51, and in S51, it is determined whether or not frequency lower limit TLLIM> current cycle information tt, and YET
In other words, if the current cycle is equal to or less than the lower limit of the pitch extraction range during note-on, the process proceeds to S52. In this case, the lower frequency limit TLLIM is set, for example, one octave below the open string scale. That is, the lower frequency limit T of STEP3 in FIG.
The tolerance is wider than TLIM (see S37). By doing so, it becomes possible to cope with a frequency change due to operation of the tremolo arm or the like.

By the above operation, the process proceeds to S52 only when the upper and lower limits of the frequency fall within the allowable range. Otherwise, the process returns to M2 of the main routine of FIG. 4 from S49 and S51 and waits for the input of the next peak.

Next, in S52, the cycle data TTP is input to the cycle data h extracted two times before, and the current cycle information tt is input to the cycle data TTP extracted last time.

Then, in S53, the current peak value c is written in the velocity VEL, and the flow proceeds to S54.

In S54, it is determined whether or not the no-change level NCHLV> (the peak value e before the previous time-the current peak value c).
In the case of, the process proceeds to S55. That is, if the previous peak value of the same polarity (e = AMP. (B) and the current peak value c greatly change, the difference exceeds NCHLV. If the pitch is changed based on the collected information, it is highly likely that the pitch will change unnaturally, so if NO is determined in S54, the process proceeds to S55.
Without performing the subsequent processing, the main routine of FIG.
Return to the processing of M2 and wait for the input of the next peak.

Next, in the case of YES in S54, the relative off counter FO
It is determined whether FR = 0. When the relative off processing described later is being performed, the relative off counter FOFR is not 0, and in such a case, the pitch is changed (S6).
Without performing the process (see No. 1), a negative determination is made in S55, and the process returns to the process of M2 in the main routine of FIG.
Then, when a determination of YES is made in S55, the process proceeds to S56 and S57 sequentially.

In S56, a two-wave ternary match condition process is performed. This processing is the processing most relevant to the present invention together with the pitch changing processing in S61, and S56 and S61 are a group, and there are two embodiments. Hereinafter, the first embodiment and the second embodiment will be described in this order. Note that the processing of S57 is not performed in FIG. 9A for convenience.

First, FIG. 9B is an operational flowchart of the two-wave ternary match condition processing of FIG. 9S S56 in the first embodiment.

In FIG. 5, in S5601, it is determined whether the value of the most recently extracted peak value AMP (b) is greater than a predetermined threshold. If the determination in S5601 is YES, the process proceeds to S5602.

In S5602, the current cycle information tt × 2 ⁻⁵ > | current cycle information tt−previous cycle data h | is determined, and in the case of YES, the process proceeds to S5603. In S5603, this cycle information tt × 2 ^-5
> | Current cycle information tt−contents of cycle register TTR |, and if YES, the process proceeds to S58 in FIG. 9A.

That is, in the S 5602, in the example of FIG. 11, the current cycle information tt = t ₅ -t ₃ (see S48) is the value of the last period data _{h = TTP = t 3 -t 1} ( see S52) Whether or not they almost match with each other, and in S5603, the current cycle information tt = t ₅ −t
_3, it is determined whether the substantially coincides with the period TTR = t ₄ -t ₂ (see S67) overlapping it, allowed range of variation of the time, as a half ⁵ of the current cycle information tt, relatively A wide change is allowed, and if these conditions are satisfied, the pitch is changed in S61 to be described later through S58 to S60 in FIG. 9A.

On the other hand, if the determination in S5601 is NO, that is, if it is determined that the value of the most recently extracted peak value AMP (b) is smaller than the predetermined threshold, the process proceeds to S5604.

In S5604, current cycle information tt × 2 ⁻⁷ > | current cycle information tt−previous cycle data h | is determined, and in the case of YES, the process proceeds to S5605. In S5605, this cycle information tt × 2 ^-7
> | Current cycle information tt−contents of cycle register TTR |, and if YES, the process proceeds to S58 in FIG. 9A.

That is, in S5604 and S5605, the current cycle information
tt is determined whether substantially coincides with the respective period information TTR and h of the last-time before last, the allowable variation width of the time, 1/2 ⁷ of the current cycle information tt, only then allowed slight changes And only if these conditions are met, the
The pitch is changed in S61 to be described later through S58 to S60.

As described above, the most recently extracted peak value AMP
When the value of (b) is small, the condition for whether or not to change the pitch is strict. Thus, in the range where the peak value of the digital output D1 in which the player is liable to intentionally change the pitch frequency is large, the condition of the pitch change can be relaxed and the operation can be quickly followed. When the peak value (intensity) of the output D1 becomes weak and is easily affected by noise or the like, the influence of noise or the like can be effectively removed by strictly changing the pitch.

As described above, after the two-wave ternary matching condition processing of FIG. 9A S56 is completed, in the next S58, it is determined whether or not the current cycle information tt> constant TTU, and if YES, the process proceeds to S59. It is determined whether cycle information tt <constant TTW, and if YES, S6
Go to 0. The case where the determination is NO in S58 and S59 will be described later.

In S60, it is determined whether or not the register STEP = 4, and in the case of YES, the process proceeds to S61.

Subsequently, as shown in S6101 in FIG. 9C, the MCP3 in FIG.
Then, the pitch change based on the current cycle information tt is performed to the tone generation circuit 501, and the process proceeds to S62.

In S62, the time constant is changed in accordance with the current cycle information tt, and the constant TTU is rewritten to (17/32) × current cycle information tt, and furthermore, the constant TTW is (31/16) × current cycle Rewritten with information tt.

Also, as will be described later, only when the relative off process is performed, STEP = 5. In this case, the process directly proceeds from S60 to S62 without changing the pitch in S61.
The time constant is changed in S62.

The process of the time constant change means that the MCP3 in FIG. 1 sets the cycle data based on the value of the current cycle information tt in the time constant conversion register CHTRR in the time constant conversion control circuit 202 in FIG. . This is as already described in the section "Detailed operation" of the "Operation of the pitch extraction digital circuit".

Then, upon completion of the process in S62, the process returns to the process of M2 in the main routine of FIG.

Next, FIG. 9D is an operation flowchart of the two-wave ternary match condition processing of FIG. 9S S56 in the second embodiment.

In this figure, in S5606, the current cycle information tt × 2 ^-5 > |
The current cycle information tt-the cycle data h |
In the case of S, the process proceeds to S5607. In S5607, this cycle information tt
× 2 ^-5 > | Current cycle information tt-Contents of cycle register TTR |
Is determined, and in the case of YES, the process proceeds to S58 in FIG. 9A.

In the second embodiment shown in FIG. 9D, unlike the first embodiment shown in FIG. 9B, it is determined whether or not the current cycle information tt substantially coincides with each of the previous and last two cycle information TTR and h. when determining the allowable variation width is 1/2 ⁵ of the current cycle information tt, to permit a wide variation relatively wide uniform will be described later via a S58~S60 of Figure 9A satisfy these conditions The pitch is changed in S61.

As described above, after the two-wave ternary matching condition processing of FIG. 9A S56 is completed, the processing of S58 to S60 is performed, which is exactly the same as in the case of the first embodiment.

The second embodiment is characterized in the pitch change processing in S61.

FIG. 9E is an operational flowchart of the pitch changing process in FIG. 9A, S61, in the second embodiment.

In FIG. 12, in S6102, it is determined whether or not the value of the most recently extracted peak value AMP (b) is larger than a predetermined threshold. If the determination in S6102 is YES, the process proceeds to 6103.

In S6103, the value of the current cycle information tt is stored in the pitch change pitch cycle information register TX. Also,
At step 6104, the contents of TX are copied to the previous pitch change pitch surrounding register ottp for the next processing.

Then, in the following S6501, pitch change processing is performed in accordance with the pitch cycle set in the register TX.

Conversely, if the determination in S6102 is NO, that is, if it is determined that the value of the most recently extracted peak value AMP (b) is smaller than the predetermined threshold, the flow proceeds to S6106.

In S6106, the current cycle information tt and the register ottp
The average pitch cycle with the pitch cycle information (see S6104) at the time of the previous pitch change set in is calculated, and the result is stored in the pitch change pitch cycle information register TX.

Then, in the following S6105, a pitch changing process is performed according to the pitch cycle set in the register TX.

As described above, the most recently extracted peak value AMP
When the value of (b) is large, the pitch is directly changed by the current pitch cycle information tt itself determined under the loose condition in the two-wave ternary match condition processing of FIG. 9A S56. Conversely, when the value of the peak value AMP (b) is small,
By using the average value with the pitch cycle used for the previous pitch change, rapid pitch change is prevented from being performed. This makes it easy for the player to intentionally change the pitch frequency.
In the range where the peak value of D1 is large, the same effect as in the first embodiment can be obtained. When the peak value (intensity) of the digital output D1 becomes weak and the digital output D1 becomes susceptible to noise or the like, the effect is obtained. It is possible to prevent a sudden change in pitch due to the influence.

As described above, in the route including the processing of the first or second embodiment, the following processing is performed in the example of FIG. That is, HN
It is determined that C = 1, MT = 1 = b, RIV = 1, and FOFR ← 0, tt
← t−TF = t ₅ −t ₃ , RIV ← 0, TF ← t = t ₅ , e ← AMP
_{(1) = a 1, AMP} (1) ← c = a 2, h ← TTP = TP (1) =
t ₃ −t ₁ , TTP ← tt = t ₅ −t ₃ , VEL ← c = a ₂ , and furthermore, the pitch is changed under the satisfaction of each of the conditions described in the first or second embodiment. Then, TTU ← (17/32) × tt, TTW ←
(31/16) × tt is set.

By the above-described operation, the pitch of the actual tone generation circuit 501 (FIG. 1) is changed in the route, and the route processing is performed in the subsequent zero-cross interrupt (detection of the next peak). Similarly, the route processing is performed in the subsequent zero-cross interrupt. Is performed. In this way, on the route, the period is simply extracted (see S67), on the route, the actual pitch change (see S61), the time constant change process (S62)
Reference).

<< Relative ON processing operation >> After the waveform number counter HNC is counted up to exceed 3 in the route S66 in STEP4 of FIG. 9A, a determination of YES is made in S40, and then the process goes to S41 and the relative Detect the ON condition.

This is because c-AMP (b)> TRLRL, and the current peak value c is smaller than the previous peak value AMP (b) by the threshold value TRLRL.
When the number exceeds the limit, that is, when the same string is picked again after string manipulation (such as by tremolo playing), such a case occurs. In this case, the determination result in S41 becomes YES, and the relative on process is performed. From S41 to do
Proceed to S78.

In S78, the period CHTIM of the highest tone fret (for example, 22th fret) is set in the time constant conversion register CHTRR of the time constant conversion control circuit 202 (FIG. 2).

After the above processing, the process proceeds to S06 of STEP0 in FIG. 5, and after note-off of the musical tone being sounded, re-sounding is started. According to the normal performance operation, in S41 of STEP 4 in FIG. 9A,
If the determination is NO, the process proceeds to S42 and proceeds to the above-described route or route.

<< Relative Off Processing Operation >> Next, the relative off processing will be described with reference to FIG. Relative off means that a silencing operation is performed in accordance with an operation of shifting from a state in which the fret operation is being performed to an open string state without picking.

In this case, the amplitude level of the waveform suddenly drops, and the difference between the peak value (peak value) AMRL2 of the previous time and the peak value (peak value) AMRL1 of the previous time exceeds (1/32) · AMRL2, The process proceeds from S46 of STEP4 in FIG. 9A to S74.

Then, the process proceeds from S74 to S75 so as to count up until the relative off counter FOFR exceeds the constant ROFCT.

Subsequently, the process goes from S75 to S48 and performs the processing of S49 to S55. However, since FOFR is not 0, the determination result of S55 becomes NO,
Immediately before entering the relative off process, the process returns to the process of M2 in the main routine of FIG. 4 without changing the pitch.

And the peak at the time of relative off enters one after another,
If NO is determined in S74, that is, in the example of FIG. 15, when the value of FOFR becomes 3 (ROFCT is 2), S74 to S76
Move to.

However, if the determination of YES is made once in S46, S46
The process proceeds from S47 to S47, and operates to reset FOFR.
Therefore, unless the condition of S46 is satisfied continuously for the number of times specified by ROFCT, the relative off processing is not performed.
If the value of ROFCT is set to a large value for a string having a high pitch, the relative off process can be performed for any of the strings after a lapse of a substantially constant time.

Next, when going from S74 to S76, the relative off counter
The FOFR is reset, the register STEP is set to 5, and the flow advances to S77 to instruct the tone generation circuit 501 (FIG. 1) to perform note-off.

When the state of this STEP is 5, the pitch extraction processing is executed in the same manner as in STEP 4, but the processing of S6 is performed without going through S60 to S61.
Since the process proceeds to step 2, the tone change circuit 501 is not instructed to change the pitch. However, the time constant changing process is performed according to the cycle extracted in S62.

Then, in the state of STEP 5, the relative-on process is accepted (S41, S78).
In the main routine shown in the figure, when it is detected that the vibration level has decreased, STEP becomes 0 in M14, and the process returns to the initial state.

Note that AMRL1 and AMRL2 used in S46 are made in S64, and the peak having the higher level (one of the maximum peak and the minimum peak) in one cycle is set to this value. This is a case where the maximum peak ak in the figure is always larger than the maximum peak bk-1, where an + 1 and an + 2, an + 2 and an +
3. The difference between an + 3 and an + 4 exceeds a predetermined value.

At this time, in the route processing, since the minimum peaks bn + 1, bn + 2, bh + 3 are extremely reduced, a NO determination is made in S54, and the process returns to the processing of M2 in the main routine of FIG. No change is made.

<< Processing operation when pitch period is inappropriate >> Next, when the pitch period is inappropriate, that is, when the pitch is extracted, harmonics having an octave relationship in S58 or S59, that is, a period higher or lower than the octave, is generated. Next, the processing when the detection is performed will be described.

Now, the constant TTU of S58 in STEP4 of FIG.
In step S301, the minimum value is set to 0, and the constant TTW is also set to the maximum value MAX. When the flow passes for the first time, YES is always determined in steps S58 and S59. The constant TTU is set to (17/32) · tt (almost one octave higher pitch period information), and the constant TTW is similarly set to S
At 62, (31/16) · tt (almost one octave bass period information) is set.

Therefore, if the octave rises rapidly (this is
When the pitch changes, when the mute operation is performed to stop the vibration of the vibrating string with a finger, or when the octave goes down (this occurs when the waveform peak is missed, etc.), Since it becomes unnatural, branching is performed so as not to change the pitch.

That is, when tt does not exceed TTU in S58, that is,
When the value becomes smaller than the value TTU obtained by multiplying the previously extracted cycle by 17/32, the process proceeds to S76. In other words, when an octave higher sound is extracted, it is considered that a mute operation has been performed, and the process goes from S58 to S76 without outputting an octave higher sound, and the sound is generated by the processing of S76 and S77 as in the case of the relative off. To stop.

In S59, when tt does not exceed TTW, that is, when ttW is larger than the value 31/16 times the previously extracted cycle, TTW, the process proceeds to S60 without proceeding to S60.
Return to the processing of.

This state is shown in FIG. Usually, when the waveform is very small near the note-off, the waveform picks up due to crosstalk of the hexa pickup and resonance of the body due to other picking. Then, for example, an input waveform as shown in FIG. 16 may be obtained, and an input waveform one octave lower may be continuously detected.

In such a case, if no processing is performed, a sound immediately below the octave is output, which is extremely unnatural. Therefore, even if Tan + 2 ≒ Tan + 3 ≒ Tbn + 2 is detected in S56 and S57, since Tan + 3> Tan + 1 × (31/16), the process proceeds from S59 to the processing of M2 in the main routine of FIG. 4 without changing the pitch. Return.

<< Operation of Dubbing Process >> Next, a process in a case where a waveform is extracted by dubbing, that is, a case where peaks having the same polarity are continuously detected will be described.

First, in the route in which the determination result in S42 of STEP4 in FIG. 9A is NO, if YES in S63, the process proceeds to S68 and the dubbing process is performed.

That is, if YES in S63, the process proceeds to S68, where the current peak value c
> It is determined whether or not it is the previous peak value AMP (b) of the same sign, and if YES, the process proceeds to S69.

In S69, the current peak value c is replaced by the previous peak value AMP (b)
Is rewritten, and the process proceeds to S70.

In S70, current peak value c> previous amplitude value (peak value) A
It is determined whether or not it is MRL1, and if YES, the process proceeds to S71, where the previous amplitude value (peak value) of the current peak value c (peak value) AMRL1
It is said.

As soon as NO is determined in S68, the process returns to the process of M2 in the main routine of FIG. Therefore, only when the peak of the new input waveform is large, it is considered that the peak of the overtone is not spread, and the peak value of the new waveform is registered.

In addition, when the result of S70 is NO and when the processing of S71 ends, the process returns to the main routine in the same manner.

FIG. 17 shows an example of the above-described dubbing processing. In this case, the state of MT = 0 is shown. In general, since the fundamental wave period and the period of the harmonic component are non-integer multiples, the phases of the harmonics are shifted, and a zero-cross of the same polarity is detected. I have to do it. In the case of the example in this figure,
Where "double" is indicated, a double state occurs.

In this case, go from S42 to S63, make a determination of YES, and
Go to In S68, in this case, (an + 2) and (an + 3)
Then, only when (an + 3) is larger than (an + 2), go to S69 and rewrite AMP (1). Further, the previous amplitude value (peak value) AMRL1 is compared with the current amplitude information (peak value c) in S70. If YES, the process proceeds to S71, and the current peak value c is changed to the previous amplitude value (peak value c). Value) FM
RL1.

Next, in the route in which the determination result in S42 of STEP4 in FIG. 9A is YES, if the determination in the next S43 is NO, the process proceeds to S72, and the doubling process is performed as described above.

That is, if NO in S34, the process proceeds to S72, where the current peak value c>
It is determined whether or not it is the previous peak value AMP (b) of the same sign. If YES, the process proceeds to S73, and after the previous peak value AMP (b) is rewritten to the current peak value c, the main routine of FIG. The process returns to the routine M2.

As soon as NO is determined in S72, the process returns to the process of M2 in the main routine of FIG. Therefore, in this case as well,
Only when the new input waveform has a large peak,
A new waveform peak value is registered.

FIG. 18 shows an example. In this example, a state where MT = 1 is shown. In this case, in the processing of STEP 4 at the time of zero cross which is written as double in the figure, go from S42 to S43, and in S43,
After the determination of YES, the process proceeds to S72. Where (an + 3) and (an +
The sizes of 2) are compared, and if (an + 3) is (an + 2)
If it is larger, a YES determination is made in S72, and AMP (1)
The value of (an + 3) is set, and if not, no change processing is performed.

By the way, in the case of the above-mentioned double processing, since the extracted time data is not used at all, the cycle information Tan + 3 does not change at all. Also, the pitch is not changed based on the cycle data.

<< Other Embodiments of the Present Invention >> As described above, in the present embodiment, the present invention is applied to an electronic guitar (guitar synthesizer), but is not limited thereto. The performance operation is detected as an input waveform signal,
Various types of tone generators that generate a sound signal different from the original signal based on the signal can be applied as long as the player can intentionally change the pitch frequency of the input waveform signal. is there.

〔The invention's effect〕

According to the present invention, it is possible to quickly follow an intentional pitch frequency change operation performed by a player, and when the intensity of an input waveform signal becomes weak and becomes susceptible to noise or the like, the influence is reduced. Can be effectively removed.

In particular, according to the first aspect of the invention, when the intensity information corresponding to the current pitch information indicates a weak intensity equal to or less than a predetermined intensity threshold, the fluctuation is allowed for the pitch information used for changing the pitch. By reducing the predetermined fluctuation threshold, it is possible to tighten the pitch extraction condition and remove the influence of noise.

According to the second aspect of the present invention, the pitch changing means is generated when the strength information corresponding to the current pitch information extracted by the pitch extracting means indicates a strength not less than a predetermined strength threshold. The pitch information to be changed should be changed according to the pitch information extracted this time, and the intensity information corresponding to the changed pitch information should be output to the pitch information generating means to correspond to the current pitch information. When the intensity information indicates an intensity equal to or less than a predetermined intensity threshold, the pitch information to be generated is obtained by averaging the pitch information extracted this time and the pitch information extracted and changed before that. Since the pitch is changed in accordance with the pitch information and the intensity information corresponding to the changed pitch information is output to the pitch information generating means, the intensity information indicates an intensity not less than a predetermined intensity threshold. When the extracted pitch changes, the pitch information is changed immediately, and the pitch information to be pronounced is changed according to the pitch information extracted this time, so that the player's intention is changed. In the process of causing the extracted pitch vibration to naturally attenuate, when the intensity information indicates an intensity below a predetermined intensity threshold, The average of the extracted pitch information and the previously extracted and changed pitch information is averaged, and the pitch is changed in accordance with the averaged pitch information. Can be prevented from being generated unintentionally, and a sudden change in pitch due to the influence of noise or the like can be prevented.

[Brief description of the drawings]

1 is an overall configuration diagram of an electronic musical instrument according to the present invention, FIG. 2 is a configuration diagram of a pitch extraction digital circuit, FIG. 3 is a diagram showing an operation flowchart of an interrupt processing routine, and FIG. FIG. 5 is a diagram showing an operation flowchart of STEP0, FIG. 6 is a diagram showing an operation flowchart of STEP1, and FIG. 7 is a diagram showing an operation flowchart of STEP2. 8 is a diagram showing an operation flowchart of STEP3, FIG. 9A is a diagram showing an operation flowchart of STEP4 (5), and FIG. 9B is a first embodiment of the two-wave ternary coincidence condition processing. FIG. 9C is a diagram showing an operation flowchart of the first embodiment of the pitch changing process, and FIG. 9D is a diagram showing the operation of the second embodiment of the two-wave ternary matching condition process. Diagram showing flowchart, ninth FIG. E is a diagram showing an operation flowchart of a second embodiment of the pitch changing process, FIG. 10 is a schematic operation explanatory diagram of this embodiment, FIG. 11 is a basic operation explanatory diagram of this embodiment, FIG. FIGS. 12 (a) and 12 (b) are explanatory diagrams of the operation of the doubling process in STEP1, FIGS. 13A, 13B, and 13C are explanatory diagrams of the operation of the doubling process in STEP2, and FIG. FIG. 15 is an explanatory diagram of the operation of the noise removal process, FIG. 15 is an explanatory diagram of the operation of the relative off process in STEP4, FIG. 16 is an explanatory diagram of the processing operation when the pitch cycle is inappropriate in STEP4, and FIG. FIG. 18 is an explanatory diagram of the operation of the doubling process in the route. 1 ... Pitch extraction analog circuit, 2 ... Pitch extraction digital circuit, 3 ... Central control unit (MCP), 4 ... Address decoder, 5 ... Tone generator, 201 ... Peak detection circuit, 202 ... Time Constant conversion control circuit, 203… Crest value capture circuit, 204… Zero cross time capture circuit, 501… Tone generation circuit, D1… Digital output,

Claims (2)

(57) [Claims] 1. A pitch extracting means for sequentially extracting pitch information from an input waveform signal, and in response to the pitch information being sequentially extracted from the pitch extracting means, intensity information of the input waveform signal is sequentially extracted. Strength extraction means, the current pitch information extracted by the pitch extraction means,
Pitch information generating means for generating pitch information according to the current pitch information only when the change is equal to or less than a change width determined by a predetermined fluctuation threshold with respect to the pitch information extracted before that, The threshold information corresponding to the pitch information indicates a threshold value equal to or less than a predetermined threshold value, the threshold value control means for reducing the predetermined threshold value, and the pitch information generated by the pitch information generating means And a pitch control means for controlling the pitch of the musical tone based on the following. 2. A pitch extracting means for sequentially extracting pitch information from an input waveform signal, and intensity information of the input waveform signal is sequentially extracted in response to the pitch information being sequentially extracted from the pitch extracting means. Intensity extracting means, pitch information generating means for generating pitch information corresponding to the pitch information extracted by the pitch extracting means, and the intensity information corresponding to the current pitch information extracted by the pitch extracting means is When indicating an intensity equal to or greater than the predetermined intensity threshold, the pitch information to be generated is changed in pitch according to the pitch information extracted this time, and the intensity information corresponding to the changed pitch information is changed to the pitch. The pitch information to be generated is output to the information generating means, and when the intensity information corresponding to the current pitch information indicates an intensity equal to or less than a predetermined intensity threshold, the pitch information to be generated is extracted from the pitch information extracted this time. And a pitch change corresponding to the pitch information obtained by averaging the extracted pitch information and the pitch information extracted and changed before, and changing the intensity information corresponding to the changed pitch information to the pitch information generating means. And a pitch control means for controlling a pitch of a musical tone based on pitch information generated by the pitch information generating means.