JP2508044B2 - Electronic musical instrument input control device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an input control device for an electronic musical instrument such as an electronic guitar.

[Background of the Invention]

Conventionally, pitch (fundamental frequency) is extracted from a waveform signal generated by a playing operation of a natural musical instrument, and a sound source device or another electronic musical instrument is controlled to artificially obtain a sound such as a musical tone. Have been developed.

In this type of electronic musical instrument, it is common to extract a pitch of an input waveform signal and then instruct a sound source device to generate sound having a frequency corresponding to the pitch.

By the way, in the case of an electronic musical instrument that extracts musical sounds by extracting pitches in this way, the frequency of the overtone may be detected instead of the original frequency, and the frequency change control may be erroneously performed.

For example, in the case of an electronic guitar, when 7 frets or 5 frets are pressed and picked, and then the left hand is released from the frets to miute, the string vibration is emitted as a second overtone.

Therefore, although the performer intends to mute, there is a problem that a musical tone having a double pitch is generated, which causes inconvenience in performance.

[Object of the Invention]

The present invention has been made in view of the above circumstances, and in an electronic musical instrument of a type that extracts a pitch of an input waveform signal to generate a corresponding musical sound, a harmonic sound (harmonic sound).
It is an object of the present invention to provide an input control device for an electronic musical instrument in which the corresponding harmonic overtone is not output as an acoustic signal by mistakenly extracting

[Main points of the invention]

That is, in order to achieve the above object, the present invention comprises a pitch extracting means for extracting the pitch of an input waveform signal at every predetermined timing and outputting it as pitch data, and a storage means for storing the pitch data output by the pitch extracting means. A comparison means for comparing the pitch data newly output by the pitch extraction means with the pitch data previously output by the pitch extraction means stored in the storage means, and the new pitch by comparing the comparison means. When it is determined that the data is not within a predetermined range including a value that is a predetermined multiple of the previous pitch data, an instruction is issued to generate a musical tone having a pitch corresponding to the new pitch data, and the comparison means If it is determined by the comparison that the new pitch data has a value within a predetermined range including a value that is a predetermined multiple of the previous pitch data, the music that is being generated is generated. And gist by comprising a control means for instructing to mute the.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

1. Circuit Configuration FIG. 1 shows a circuit configuration of the embodiment. In this embodiment, the present invention is applied to an electronic guitar (guitar synthesizer). These are signals from pickups provided on each of the six strings stretched on the body and converting vibrations of the strings into electric signals.

The tone signal from the input terminal 1 is a pitch extracting circuit P ₁
PP ₆ (In the figure, only the internal structure of the first string P ₁ is shown.) Each of the internal amplifiers 2... Is amplified by a low-pass filter (LPF) 3. Basic waveform is extracted and maximum peak detection circuit (MAX)
4 ..., minimum peak detection circuit (MIN) 5 ... and zero-cross point detection circuit (Zero) 6 ... The low pulse filter 3 ... has the vibration sound frequency f of the open string of each string.
Cutoff frequency at 4f which is 4 times Is set. This is because the frequency of the output sound of each string is 2
It is based on being within an octave. In the maximum peak detection circuit 4 ..., the maximum peak point of the musical tone signal is detected, and the Q output of the flip-flop 14 ... The AND output of the output and the inverted output of the inverter 30 of the zero-cross point detection circuit 6 ... Is the interrupt command signal via the AND gate 24. As the minimum peak detection circuit 5
However, the minimum peak point of the tone signal is detected, and at the rising edge of the detected pulse signal, the Q output of the flip-flop 15 connected at the subsequent stage becomes a high level, and the output of the flip-flop 15 and the zero cross point detection are performed. Circuit 6 ...
The AND output with the output of ... is an interrupt command signal via the AND gate 25 Is given to CPU100 as. FIG. 2 shows the output waveform signals of the respective parts in FIG. 1, where is a low pass filter 3 output, is a maximum peak detection circuit 4 output, is a minimum peak detection circuit 5 output, is a zero cross point detection circuit 6 output, Interrupt command signal INT _a that is output from AND gate 24, and interrupt command signal INT _b that is output from AND gate 25
Are shown respectively.

That is, the maximum peak point is detected and the flip-flop 14
Interrupt command signal when the waveform crosses from positive to negative while is at high level Is given to the CPU 100 as shown in FIG. 2, and conversely, when the minimum peak point is detected and the flip-flop 15 is at the high level, when the waveform changes from negative to positive,
Interrupt command signal as shown Input to CPU100.

Immediately after receiving these interrupt command signals, the CPU 100 responds to the corresponding flip-flops 14..., 15.
Against clear signal And reset. Therefore, no matter how many times the zero cross point is passed until the next maximum peak point or minimum peak point is detected, the corresponding flip-flops 14 ..., 15 ... are in the reset state, so the CPU 100 will not be interrupted. .

Then, in the CPU 100, the interrupt command signal is output by the vibration output of the string. Or Is given to instruct the tone generator circuit 9 to generate a scale tone according to at least one of the time intervals. It should be noted that at the start of sounding, generation of an open string scale tone may be started and corrected to the correct frequency after pitch extraction. The operation at the start of sound generation will be described later.

Then, the above-mentioned time interval is set by the counter 7 as described later.
And the work memory 101. That is, the work memory 101 stores various data such as the count value of the counter 7 at the time of the zero crossing point immediately after the maximum peak point or the minimum peak point.

After the start of the tone generation, the frequency of the tone being generated is variably controlled in accordance with the sequentially obtained time interval data. That is, the CPU 100 transmits data specifying the scale, that is, a scale name code corresponding to a scale name of one or more semitones, a difference value code of less than a half tone, and the like, and as a result, a tone signal having a corresponding frequency is generated from the tone generator circuit 9. Sound system 10
The sound is output more. The tone generator circuit 9 may be provided inside the electronic guitar, or may be a separate tone generator connected via an interface such as MIDI.

Further, the tone signal from the low pass filter 3 ... Is given to the A / D converter 11 ... And converted into digital data corresponding to the waveform level.

The output of the A / D converter 11 is a latch 12
Be latched on. The latch signal for this latch 12 ... Is generated by the output of the flip-flops 14 ..., 15 ... through the OR gate 13 ..., and the latch 12 ... A signal indicating the level of the waveform at that time is stored. Also,
The latch signals L _{1 to} L ₆ from this OR gate 13 ... are CPU100.
Also given to.

Then, the output of the latch 12 ... Is given to the CPU 100, and the sound generation start, stop, re-sound generation start, and control of the sound emission level (volume) of the output sound are performed according to this data.

That is, in the CPU 100, when the absolute value of the data indicating the waveform level given from the A / D converter 11 becomes equal to or more than a predetermined fixed value, the tone generation of the musical tone is started.
When this data falls below a certain value, a mute instruction is issued to terminate sound emission. The details of the operation are as described later.

Note that FIG. 1, A / D converter 11, but are separately provided respectively corresponding to the pitch extracting circuit P ₁ to P _6, the one
It is of course possible to use the A / D converter in a time-sharing manner.

The sound source circuit 9 performs at least 6
A channel tone generation system is formed.

Operation Next, the operation of this embodiment will be described. Figure 3 shows CP
FIG. 4 is a flow of the U100 interrupt routine, and FIG. 4 is a flow of the main routine. Incidentally, this FIG. 3 and FIG.
Although the figure shows only the processing for one string, the processing for each string is exactly the same, so it can be considered that the CPU 100 executes the processing for each string in a time-division manner.

Before describing the specific operation of the CPU 100, main registers in the work memory 101 will be described.

The STEP register takes each stage of 0, 1, 2 (normal state) or 0, 1, 2, 3 (state in which harmonics sound appears), and as the string vibration occurs (see FIG. 5 (a)). ), The contents change as shown in FIG. 5 (b). When this STEP register is 0, it means a note-off (silence) state.

The SIGN register indicates whether the zero-cross point for period measurement is the next zero-cross point after the maximum peak (MAX) point or the next zero-cross point after the minimum peak (MIN) point. When is the latter.

The T register stores the value of the counter 7 at a specific point for measuring the cycle of the input waveform. The counter 7 is performing a free-running operation of counting with a predetermined clock.

The AMP (i) register is connected to the A / D converter 11 to the latch 12
AMP (1) is a register for the maximum peak and AMP (2) is a register for the minimum peak.

The data representing the measured cycle is input to the P or P'register, and the CPU100 based on the contents of this register.
Controls the frequency change of the sound source circuit 9.

Further, as will be described later, in this embodiment, for various judgments,
Since three constants (threshold level) are set in the CPU 100, they will be described next.

The first one is ONLEV1, and as shown in FIG. 5 (a), the note-off state (at STEP = 0, this ON
When a peak value larger than the LEV1 value is detected, it is assumed that the string has been picked and the operation for period measurement is performed by the CPU100.
Starts executing.

ONLEVII is in the note-on state (while sounding),
If the difference between the previous detection level and the current detection level is more than this value, it is determined that there is an operation such as tremolo playing method.
This is for performing re-pronunciation start (relative on) processing.

As shown in FIG. 5A, the OFFLEV performs a note-off (silence) process when a peak value less than this value is detected in the note-on state (while sounding).

From the above description, it will be easy to understand the operation of the interrupt routine and the main routine described below.

Now, the interrupt command signal INT _a, which is the output of the AND gate 24 or AND gate 25, Yotsute the advent of the CPU100 of INT _b, the interrupt processing of the third diagram.

That is, the interrupt command signal INT _a On input, first processing step P _1, the a register in the CPU100 to 1, an interrupt command signal INT _b On input, first step P ₂ in O connexion above a register in the processing Set 2 to

And then at step P _3, the t registers in CPU 100, to Purisetsuto the value of the counter 7. Then the peak level data in step P ₄ in the A / D converter 11 to perform setting from the latches 12 to b register read the CPU 100.

Then, in step P ₅ , the flip-flop 14 or the flip-flop 15 is cleared.

At the following step P _6, the a, b, the contents of t register transfer ends stored interrupt processing in the work memory 101.

In the main routine (FIG. 4), in step Q _1, and Inishiyaraizu processes such as the registers, step
In Q ₂ , set the STEP register to 0.

Then, sense step Q _3, the O connexion work memory 101 to the interrupt process described above, a ', b', the contents of t '(the a, b, that the same is recorded in the far and t A), b ', and t') are written, and if no interrupt processing is performed and there is no new data, it is determined to be NO, and this step Q Repeat ₃

Then, when the determination of YES at step Q _3, the contents of a proceeding to the next step _{Q 4 ', b', t} ' reads, in the subsequent step Q _5, the AMP (a') register storage The peak value of the peak point of the same kind (the maximum or minimum of 1 or 2 which is the same value as a ') is read into the C register in the CPU 100, and the value of b'which is the peak value extracted this time is set as above. Set in AMP (a ') register.

Well, then in step Q ₆ to Q _8, whether the contents of the STEP register is respectively 1, 2, 3 and Jiyatsuji. Now, if we are the first state, STEP register is 0, so the determination in step Q _6, Q _7, Q ₈ both NO is made. Then, in the next step Q ₉ , it is judged whether or not the peak value b ′ detected this time is larger than ONLEVI.

If the judgment in step Q ₉ is NO, the process for starting sound generation is not yet performed, and therefore the process returns to step Q ₃ . Temporarily, the fifth
As shown in Figure (a), if a larger input than ONLEVI is given from the OHAS filter 3, the judgment at step Q ₉ is YE.
Connect to S and proceed to step Q ₁₀ .

In step Q ₁₀ , 1 is set in the STEP register, and then in step Q ₁₁ , the SIGN register is set to a '(that is, 1 at the zero-cross point immediately after the maximum peak point and 2 at the zero-cross point immediately after the minimum peak point). Input the value of into the SIGN register.

Then, in step Q _12, to excisional the time of value, ie, the zero-crossing point Zero1 of t 'in the T register.

In this way, the contents of a '(1 in FIG. 5 (a)) are stored in the SIGN register, the contents of b'are stored in the AMP (1) register, and the contents of t' (time of the zero cross point Zerol as described above). ) Has been set in the T register. Then return to step Q ₃ again.

This completes the processing of the main routine immediately after the zero-cross point Zero1 in FIG. 5 (a). Now, next, in the process of the main routine immediately after the zero-cross point ZERO2, perform the above step Q ₃ to Q _5, YE by the following step Q ₆
And the judgment of S, Yuku to step Q _13.

Now, as shown in FIG. 5 (a), when the input waveform rises (that is, changes in the positive direction), the SIGN register is set to 1, and this time the negative peak point, that is, the minimum peak point. Since it has passed through, the a'register has a value of 2, and in this step Q ₁₃ , a NO judgment is made and the operation returns to step Q ₃ without any processing.

Then, at the time of arrival of the zero-cross point Zero3, perform the step Q ₃ ~Q _6, Q ₁₃ again, this time a determination of YES is made at step Q _13, the process proceeds to step Q _14, shown in FIG. 5 (b) Set the contents of the STEP register to 2 and set the next step Q ₁₅
From the current interrupt time in the t'register at T
The time of the zero-cross point Zero1 in the register is subtracted, and the difference, that is, the length of P'shown in FIG. 5 (c), that is, a value which is one cycle of the waveform is stored in the P'register.

Next, at step Q ₁₆ , the contents of t ′ are transferred to the T register and a new period measurement is started. In step Q _17, a musical tone having a frequency corresponding to the contents of the P 'register, and an indication of note-on so as to generate from the sound source circuit, as FIG. 5 (d), the sounding start from the timing Like

Now, the next zero-cross point Zero4 (see Fig. 5 (a))
In the main routine immediately following executes step Q ₃ to Q _7, and a determination of YES since the contents of the STEP register is 2 at step Q _7, followed by snow to step Q _18, the value of b ' Is over the value of OFFLEV (see Fig. 5 (a)), and the peak level is still high.
_{At 18} , a YES decision is made and the operation proceeds to Step Q ₁₉ .

In step Q _19, so as to whether the Jiyatsuji the process Rirateibuon (relative on). That is,
It is judged whether or not the current peak value b ′ is larger than the previous peak value by ONLEVII, that is, whether or not the extracted peak value is suddenly increased during sound generation.

Normally, if the string vibrates, natural damping is performed.
The determination of the Q ₁₉ NO but, if I like tremolo connexion, while the previous string vibrations Finished attenuated, are operated string again, the determination in step Q ₁₉ may become YES .

In this case, then it jumps from step Q ₁₉ to step Q _10, perform the step Q _11, Q _12, resulting STEP register is 1, execute subsequent acts the same as the operation of the sound at the start as described above. That is, after that, step Q ₆ → Q ₁₃
→ Q ₁₄ → Q ₁₅ → Q ₁₆ → Q ₁₇ is executed and the re-pronunciation process is performed. At this time, re-sound generation with an attack portion is started.

Now, in the normal state, step Q ₁₉ is followed by step Q
Go to step ₂₀ and check if the contents of the SIGN register and a'register match. Since the zero crossing point is Zero 4, the SIGN register is 1 and the a'register is 2, so at this step Q ₂₀ , NO is set and the process returns to step Q ₃ .

At the time of detection of the next zero-crossing point Zero5, step Q ₃ ~Q
₇ , Q _{18 to} Q ₂₀ are executed, YES is determined in step Q ₂₀ , and steps Q ₂₁ and Q ₂₂ are executed, and a new cycle, that is, Zero
Set the time from 3 to Zero 5 to the P register.

Then, in step Q ₂₃ , P is P ′ based on the cycle P found this time and the cycle P ′ found last time. Determine if greater. The value of a is, for example, about 0 to 0.006 in consideration of an error of a semitone or less, but may be appropriately changed by experiment.

By the way, in this step Q ₂₃ , usually YES is judged,
Follow the pitch detected this time proceed to step Q ₂₄ go-between, to the sound source circuit 9, the indication of the frequency change.

In this way, not only the frequency change in semitone units but also the frequency change in less than one semitone is realized in real time. In the subsequent step Q ₂₅ to transfer the contents of the P register to P 'register,
Back to step Q _3.

Hereinafter, the processing in the main routine following the interrupt processing, step _{Q 3 ~Q 7, Q 18,} Q 19, Q 20 or return to step Q ₃ through, or step Q ₃ ~Q _7, Q _18, Q
Perform steps ₁₉ , Q _{20 to} Q ₂₅ (when not performing relitate on processing).

Then, at step Q ₁₈ , the input peak value is OFFLE
If so it falls below V, a determination of NO at step Q _18, followed by the step Q ₂₆ content of snow STEP register 0
And then performs a note-off process in step Q _27, stops the generation of the musical tone that has been outputted from the sound source circuit 9 before.

By the way, when a musical sound is generated with a period between the zero-cross points Zero6 and Zero7 as a cycle (Large 5 Fig. (C) noP '), the performer releases the finger from the flute and miutes (left-handed miute). As a result, a harmonics sound of approximately half the period appears, and when the zero-cross point Zero8 is detected, in the processing of the main routine immediately after that, step Q ₃ ~
Execute Q ₇ , Q _{18 to} Q ₂₃ , this time in step Q ₂₃ Condition is detected, the process proceeds from step Q ₂₃ to step Q ₂₈ , the STEP register is set to 3, and the note-off process is performed in the subsequent step Q ₂₇ . Therefore, at this point, the sound source circuit 9 is instructed to start muting.

Next, in the main routine immediately after the time of arrival of the zero-cross point Zero9, perform the step Q ₃ ~Q _8, YES in step Q ₈
And proceed to step Q ₂₉ . When the zero-cross point Zero9, b 'of the magnitude is large than OFFLEV (see FIG. 5 (a)), the determination is YES, the snow to step Q _30, for similar to step Q ₁₉ described above Rirateibuon Play jazz.

If YES in step Q ₃₀ , step Q ₃₀
Perform ₁₀ to Q _12, in subsequent processing, the re-start of sounding.

Now, at step Q ₃₀ , you can do NO jersey, and at step Q ₃
Go back. Thus, for each incoming zero-cross point, to perform the step _{Q 3 ~Q 8, Q 29,} Q 30.

Then, at the timing of zero-cross point Zero10 of FIG. 5 (a), Yotsute to the next main routine executes the step Q ₃ ~Q _8, Q _29, the contents of b 'is so small than OFFLEV, In step Q ₂₉ , it is judged NO, and in step Q ₃₁ , the STEP register is initialized to 0. Then, to complete the series of sound processing, returns to step Q _3.

As described above, in the present embodiment, when the harmonics sound is input, the CPU 100 performs the determination process so as not to malfunction, so that the performance is not unnatural. Also, since miute is applied from that time, the effect intended by the performer can be obtained.

Moreover, in the above embodiment, at the time of normal note-off,
When the STEP register is set to 0 immediately and the pitch change is 1 octave or more, the STEP register is set to 3 and then set to 0 by waiting for the input level to become small. The vibration of the strings may still continue, and it is possible to prevent the trigger to start sounding again due to the waveform input of ONLEVI or higher immediately after the muting.

In the above embodiment, the CPU 100 performs an interrupt process at the zero-cross point immediately after each peak point of the maximum peak point and the minimum peak point, and in the main routine immediately after each peak point, the sound generation start and the cycle calculation are performed. Although the processes such as relaunch on, start of mute, etc. are performed, these processes may be directly performed at the time of detecting each peak point, that is, at the time of detecting the maximum peak point and the minimum peak point. In that case, the exact same result can be obtained. In addition, the same processing as described above may be performed, for example, by detecting the zero-cross point immediately before the peak point. In addition, the way of taking a reference point can be variously changed.

Further, the circuit or method for extracting the pitch can be variously changed, and in addition to the above-mentioned one, the pitch may be obtained by calculating the correlation value of the waveform.

Further, in the above embodiment, each process is executed in the main flow, but the same process may be executed in the interrupt process.

Further, in the above embodiment, the present invention is applied to an electronic guitar (guitar synthesizer).
It is not necessarily limited to that. Pitch extraction is performed from a voice signal or an electric vibration signal input from a microphone or the like to obtain an acoustic signal different from the original voice signal.
Any form may be used as long as it is a system that generates at the corresponding pitch or scale frequency. Specifically, the present invention can be similarly applied to a device having a keyboard, such as an electronic piano, a computerized wind instrument, and a stringed instrument such as a computerized violin or koto.

〔The invention's effect〕

As described above, according to the present invention, when it is determined that the newly obtained pitch data is not within a predetermined range including a predetermined multiple of the previously obtained pitch data, a normal pitch change is performed. Therefore, it is instructed to generate a musical tone with a pitch corresponding to the new pitch data, and the new pitch data is within a predetermined range including a value that is a predetermined multiple of the previous pitch data. If it is judged, it is considered that an unintentional harmonics sound is generated when trying to mute, and it is instructed to mute the musical sound that is being generated, so the miute effect intended by the performer. It is possible to prevent the generation of erroneous and unnatural sound.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention, FIG. 1 is a diagram showing a circuit configuration of the same embodiment, FIG. 2 is a diagram showing time charts of signals of respective parts in FIG. 1, and FIG. FIG. 4 is a diagram showing a flow chart of an interrupt routine of the CPU, FIG. 4 is a diagram showing a flow chart of the main routine of the CPU, and FIG. 5 is a diagram showing a time chart showing a sounding operation. 1 ... Input terminal, 4 ... Maximum peak detection circuit, 5 ... Minimum peak detection circuit, 6 ... Zero cross point detection circuit, 7 ... Counter, 9 ... Sound source circuit, 14,15 ... Flip flop, 100 ... C
PU, 101 ... work memory, P ₁ ~P ₆ ... pitch extraction circuit.

Claims (1)

(57) [Claims] 1. A pitch extracting means for extracting the pitch of an input waveform signal at a predetermined timing and outputting it as pitch data, a storage means for storing the pitch data output by the pitch extracting means, and a new pitch extracting means. Output pitch data,
By comparing the comparison means for comparing the pitch data outputted by the pitch extraction means previously stored in the storage means with the comparison means, the new pitch data is a value of a predetermined multiple of the previous pitch data. If it is determined that the new pitch data does not fall within the predetermined range, the new pitch data is instructed to be generated, and the new pitch data is compared with the previous pitch. An input device for an electronic musical instrument, comprising: a control unit for instructing to mute a musical tone being generated when it is determined that the value is within a predetermined range including a value that is a predetermined multiple of the data.