JP4438262B2 - Effect adding device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an improvement of an effect adding device for adding an effect to a musical sound signal output by playing a musical instrument.
[0002]
[Prior art]
The conventional effect adding device is configured to receive a sound signal from an instrument such as a guitar and output a signal obtained by adding the effect to the amplifier to listen to the sound with the effect added. The sound effect adding device is provided with operating means such as a pedal, and the effect adding function is activated by operating the operating means. Therefore, the performer played the musical instrument while operating the operating means to add a desired effect to the musical sound signal.
[Problems to be solved by the invention]
However, such a conventional effect adding device requires an operation means such as a pedal, and it is necessary to operate the operation means while performing, so the player wants to add the effect. It is not always easy to operate the operation means, and it has been difficult to add effects in real time due to operation delay.
[0003]
Therefore, the present invention has been made to solve such a conventional problem, and an object of the present invention is to provide an effect adding device that can automatically add an effect to a musical tone signal by a playing method of a musical instrument. And
[0004]
[Means for Solving the Problems]
In order to achieve the above object, the present invention is an apparatus for adding an effect to a musical tone signal from a musical instrument,
Envelope detecting means for generating an amplitude envelope signal based on the musical sound signal;
A comparison means for outputting a comparison signal according to a comparison result between the generated amplitude envelope signal and a preset threshold value;
Gate means for opening and closing in response to the comparison signal;
Mixing means for mixing the musical sound signal and the signal from the gate means;
Wavelength detection means for determining the wavelength of the fundamental tone when the comparison signal indicates that the musical tone signal is in a sustained state;
A signal generating means for generating a signal having a frequency according to the obtained wavelength;
The signal generated by the signal generating means is configured to be supplied to the gate means,
The wavelength detecting means includes
Means for sequentially determining the tone length of the tone signal by determining that the tone signal is sustained when a comparison signal indicating that the level of the amplitude envelope signal exceeds the threshold is received;
Looking at the sequentially obtained fundamental wave lengths on the time axis, both the current wavelength, which is the newest fundamental wave length, and the current average wavelength, which has been updated using the fundamental wave length previously obtained, are displayed. When the absolute value of the difference between wavelengths is less than 1/16, a process of sequentially increasing the number of matches is received, and a comparison signal indicating that the level of the amplitude envelope signal does not exceed the threshold value is received Means to continue repeatedly until
See containing and means for the operation of the signal generating the said signal generating means only when the excess of number of matches threshold value which this match count is preset,
The average wavelength update is
If the absolute value of the difference between the previous current wavelength (B) one previous to the current current wavelength and the previous average wavelength (A) with respect to the previous current wavelength is less than 1/16, “A + While the value obtained by the calculation of (B−A) × 0.25 ”is used as the current average wavelength in the current increase determination process of the number of matches,
In other cases, and as characterized in, that a process using the current wavelength (B) itself of the last to increase determination processing of this the match count as the current mean wavelength.
[0005]
In the present invention , the comparison means outputs a comparison signal according to a comparison result between the amplitude envelope signal generated by the envelope detection means and a preset threshold value, and the wavelength detection means outputs the comparison signal as a musical tone. When indicating that the signal is in a continuous state, the wavelength of the fundamental tone is obtained, and the signal generating means generates a signal having a frequency corresponding to the obtained wavelength. When the signal generated by the signal generating means is supplied to the gate means and the gate is opened, the music signal and the signal from the gate means are mixed by the mixing means . Therefore, if a musical instrument is played such that the musical sound signal is maintained at a specific wavelength, an effect can be automatically added to the musical sound signal.
[0014]
The gate means is configured to gradually open from the closed state in response to receiving a comparison signal indicating that the level of the amplitude envelope signal does not exceed the threshold value. You can also
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
(Constitution)
FIG. 1 is a configuration diagram of an effect adding device 100 according to the first embodiment of this invention. The effect adding apparatus 100 includes a multiplier 30 that directly inputs a musical sound signal output by playing a musical instrument such as a guitar. Furthermore, an envelope detector 10 that directly inputs a musical sound signal and an oscillator 20 that is connected to the envelope detector 10 and outputs a sine wave signal to the multiplier 30 are provided.
[0015]
The envelope detector 10 includes a full-wave rectification unit 12 that performs full-wave rectification on the musical sound signal, and an integration unit 14 that performs integration with a predetermined time constant in order to obtain a signal indicating an envelope (envelope) of the full-wave rectification signal. It has. Needless to say, the integration time constant can be set as appropriate, and even if a signal showing a perfect amplitude envelope cannot be obtained, a signal showing a pseudo amplitude envelope sufficient for the subsequent processing can be obtained. The time constant is set as follows.
[0016]
The oscillator 20 amplifies the envelope signal output from the envelope detector 10 with a set amplification factor (G), adds the amplified signal and the offset (Of), and adds the sine wave oscillator 26. And an adder 24 to be input. As indicated by the straight line A in FIG. 2, the sine wave oscillating unit 26 generates and outputs a sine wave signal having a frequency (f) changed according to the envelope signal level (L). Then, when the offset (Of) to be added by the adder 24 is added, the characteristic of “envelope signal level-sinusoidal frequency” of the oscillator 20 is changed as indicated by reference numeral C, as indicated by reference numeral B, so that the overall The offset is added to the characteristics. Further, by changing the amplification factor (G) of the amplifier 22, the degree of inclination of the straight line indicating the characteristics is changed as indicated by reference symbols C and D.
[0017]
Therefore, the output characteristic of the sine wave signal can be adjusted by providing the amplifier 22 for amplifying the envelope signal and the adder 24 for giving an offset to the amplified signal.
[0018]
(Operation)
Next, the operation will be described. When a musical sound signal as shown in FIG. 3 (a) (FIG. 3 shows horizontal axis time, vertical axis level) is input, the full-wave rectifier 12 performs full-wave rectification on the input musical signal (FIG. 3 (b)). )reference). Next, the integrator 14 integrates the full-wave rectified signal to generate and output a pseudo (amplitude) envelope signal (FIG. 3C). While this envelope signal is amplified by the amplifier 22, an offset (Of) is added by the adder 24 and is input to the sine wave oscillator 26. In response to this, the sine wave oscillator 26 generates a sine wave signal having a frequency that takes into consideration the characteristics determined by the amplification factor and offset (Of) of the amplifier 22 and outputs the sine wave signal to the multiplier 30.
[0019]
The multiplier 30 multiplies the original tone signal and the sine wave signal, and outputs a signal obtained by modulating the tone signal with the sine wave signal as a tone signal after the effect is added.
[0020]
Therefore, according to the first embodiment, the oscillator 20 generates and outputs a sine wave signal having a frequency corresponding to the level of the amplitude envelope signal generated by the envelope detector 10, and the multiplier 30 generates the original tone signal. Since modulation is performed by multiplying the generated sine wave signal, a modulated sound corresponding to the amplitude level of the musical sound signal is output. Therefore, it is possible to automatically add an effect without performing an operation means such as a pedal by performing a performance with a musical tone signal level, and an interesting effect can be realized depending on the strength of the performance.
[0021]
(Second Embodiment)
(Constitution)
FIG. 4 is a configuration diagram of the effect adding device 101 according to the second exemplary embodiment of the present invention. The effect adding apparatus 101 includes a rotary speaker 50 that directly inputs a musical sound signal output by playing a musical instrument such as a guitar. Furthermore, an envelope detector 10 that directly inputs a musical sound signal and a comparator 40 that outputs a comparison signal corresponding to a comparison result between the envelope signal and a preset threshold value are provided. Since the envelope detector 10 in the present embodiment has the same configuration as the envelope detector 10 shown in FIG. 1, detailed description of the configuration and operation of the envelope detector 10 in this embodiment is omitted.
[0022]
The comparator 40 is configured to give hysteresis to the threshold value, and the hysteresis can be set by the threshold value setting unit 42. As shown in FIG. 5, when the upper threshold value TU and the lower threshold value TL are set and the envelope signal level exceeds the upper threshold value TU, the comparison signal becomes a high level signal. . When the high level signal is output once exceeding the upper threshold level TU as shown by the signals W1 and W2, the high level signal output state is maintained even if there is a slight level decrease, and the signal level is lowered. A low level signal is output as a comparison signal only when it falls below the side threshold value TL. Thus, when the comparison signal is high level, the level of the envelope signal is high, while when the comparison signal is low level, it means that the envelope signal level is low.
[0023]
Further, when the threshold setting unit 42 is operated, the levels of both thresholds TU and TL can be moved in the vertical direction as indicated by the symbol X. The threshold values of both thresholds TU and TL become longer as the threshold values TU and TL are set higher, while the threshold values TU and TL are both set lower. The threshold widths TU and TL are configured to be short. When the signal level is small as in the envelope signal W1, the threshold width A1 is shortened. On the other hand, when the signal level is large as in the envelope signal W2, the threshold width A2 is lengthened to increase the accuracy of the comparison operation. It is for improving.
[0024]
FIG. 6 is a schematic configuration diagram of the rotary speaker 50. Sound from the speaker 53 fixed to a predetermined member is radiated toward the diffusion drum 54. The diffusion drum 54 is rotationally driven and controlled by a motor 55. Thus, the Doppler effect can be obtained and effects such as vibrato and tremolo can be added. The operation of the motor 55 is controlled by the control unit 52. When the control unit 52 obtains a high level signal from the comparator 40, a high-speed operation command is given to control the rotation operation of the diffusion drum 54 at a high speed of about 600 (rpm). .
[0025]
On the other hand, when the control unit 52 obtains a low level signal from the comparator 40, a low speed operation command is given to control the rotation operation of the diffusion drum 54 at a high speed of about 60 (rpm). Thus, the diffusion drum 54 rotates at a high speed or a low speed according to the comparison signal. The control unit 52 can perform a high speed operation when a low level signal is obtained from the comparator 40, and can perform a low speed operation when a high level signal is obtained from the comparator 40. The control unit 52 may be provided on the comparator 40 side.
[0026]
(Operation)
Next, the operation will be described. Similar to the operation of the first embodiment, when a musical tone signal as shown in FIG. 3A (FIG. 3 is horizontal axis time, vertical axis level) is inputted, the full-wave rectifying unit 12 receives the inputted musical tone signal. Is full-wave rectified (see FIG. 3B). Next, the integrator 14 integrates the full-wave rectified signal to generate and output a pseudo (amplitude) envelope signal (FIG. 3C).
[0027]
Next, the operation of the comparator 40 will be described with reference to FIG. When the envelope signal W3 as shown in FIG. 7 is input, a high level signal (high speed) is output only when the signal level exceeds the upper threshold value TU. The output signal is maintained at a high level as long as the signal level slightly increases or decreases, but a low level signal (low speed) is output when the signal level falls below the lower threshold value TL. When the signal level rises again and exceeds the lower threshold value TL and further exceeds the upper threshold value TU, a high level signal (high speed) is output again. When the signal level falls below the lower threshold value TL, a low level signal (low speed) is output. As described above, when the signal level is strong by the comparison operation with the threshold value having hysteresis, a high level signal is output, whereas when the signal level is weak, a low level signal is output.
[0028]
The control unit 52 drives and controls the motor 55 so that the diffusion drum 54 operates at a high speed when a high level signal is obtained as a comparison signal. On the other hand, when a low level signal is obtained as a comparison signal, the control unit 52 controls the diffusion drum 54. The motor 55 is driven and controlled so as to operate at a low speed. Thus, the original musical tone signal is output with the effect added by the rotary speaker 50.
[0029]
Therefore, according to the second embodiment, the comparator 40 outputs a comparison signal according to the comparison result between the (amplitude) envelope signal generated by the envelope detection unit 10 and a preset threshold value, and the control unit 52 controls the rotation operation of the diffusion drum 54 (rotating body) in accordance with the comparison signal, so that the rotation operation of the diffusion drum 54 can be controlled in accordance with the amplitude level of the tone signal. Therefore, for example, by making the performance of the musical instrument a performance in which the tone signal level is increased or decreased, it is possible to automatically add an effect using the diffusion drum 54 without requiring an operation means such as a pedal.
[0030]
The control unit 52 controls the operation of the diffusion drum 54 at a high speed (or a low speed) when the level of the envelope signal exceeds the threshold value, while the speed is low when the level of the envelope signal does not exceed the threshold value. Since the operation of the diffusion drum 54 is controlled (or at high speed), the control operation of the diffusion drum 54 can be realized with a very simple one. Furthermore, the comparator 40 can set hysteresis in the threshold value, and the hysteresis width can be changed, so that the accuracy of the comparison operation can be improved.
[0031]
The example using the rotary speaker 50 that actually rotates the diffusion drum has been described above. However, this portion may be replaced with a rotary speaker simulator. The above rotary speaker 50 actually adds the effect by changing the pitch and tone by changing the distance that the musical sound reaches the listener's ear by actually rotating the diffusion drum 54. By changing the delay of the tone signal by a processor such as a DSP (digital signal processor) without actually rotating the drum 54, the change in the arrival time of the sound according to the change in distance due to the rotation is simulated. This is a device that adds an effect by changing the pitch and tone color.
[0032]
(Third embodiment)
FIG. 8 is a configuration diagram of the effect adding device 102 according to the third embodiment of this invention. The effect adding device 102 includes a wavelength detector 60 and an envelope detector 10 that directly input a musical sound signal output by playing a musical instrument such as a guitar, a comparator 40, an oscillator 70, a gate unit 80, a mixer 90, and the like. It has. Since the envelope detection unit 10 and the comparator 40 of the effect adding device 102 have the same configuration as that of the effect adding device 101 shown in FIG. 4, the detailed configuration and operation thereof are omitted.
[0033]
While the envelope signal exceeds the upper threshold value TU and the comparator 40 outputs a high level signal, the wavelength detector 60 performs an operation as described later. On the other hand, when the envelope signal falls below the lower threshold value TL and the comparator 40 outputs a high level to low level signal, the gate unit 80 changes from the closed state to the open state in response to this. A signal having a certain frequency from 70 is guided to the mixer 90, and the original tone signal and the signal from the oscillator 70 are mixed and output.
[0034]
Furthermore, as shown in FIG. 9, the gate unit 80 does not open at once in response to reception of a low level comparison signal as shown by reference numeral G1, but gradually closes with a time constant. To the open state (reference numeral G2).
[0035]
Further, while the comparison signal is a high-level signal, the wavelength detection unit 60 detects the fundamental sound wave length (pitch) of the musical sound, assuming that the musical sound signal is in a continuous state, and passes the operation to the processing unit 64 at a predetermined cycle. A repetition pitch detection unit 62 and a processing unit 64 that performs an operation for accurately obtaining a fundamental wave length, which will be described later, are provided. Further, the oscillator 70 is configured to generate a signal having a frequency corresponding to the fundamental wave length passed from the processing unit 64 and supply the signal to the gate unit 90.
[0036]
(Operation)
Next, the operation will be described. Similar to the operation of the first and second embodiments, when a musical sound signal as shown in FIG. 3A (FIG. 3 is horizontal axis time, vertical axis level) is input, the full-wave rectifier 12 is input. The musical sound signal is full-wave rectified (see FIG. 3B). Next, the integrator 14 integrates the full-wave rectified signal to generate and output a pseudo (amplitude) envelope signal (FIG. 3C).
[0037]
The comparator 40 to which the envelope signal as shown in FIG. 10 is input outputs a high level signal when the signal level exceeds the upper threshold value TU. The high level output is maintained even if the signal level is slightly higher or lower, but a low level signal is output when the signal level falls below the lower threshold value TL. It is assumed that the tone signal is in a continuous state from the rise in the rising region of the tone signal while the high level signal is output, while the tone signal enters the attenuation region when the low level signal is output.
[0038]
In this rising region, the pitch detection unit 62 performs an operation of sequentially detecting the fundamental sound length based on the musical sound signal by a known algorithm such as a correlation method and sequentially passing it to the processing unit 64. FIG. 11 is a flowchart for explaining the operation of the processing unit 64 that sequentially receives this and obtains the fundamental wave length.
[0039]
In step S1100, the processing unit 64 stores the average wavelength in the variable A, stores the current wavelength in the variable B, and stores the number of matches in the variable D. Next, in steps S1110 and S1120 , it is determined whether or not the absolute value of the difference between the average wavelength and the current wavelength is less than “1/16”. When the difference between the absolute values is less than “1/16” (Yes), the process proceeds to step S1140 as a pitch unchanged state, while when the difference between the absolute values is not less than “1/16” (No). Shifts to step S1130 on the assumption that a pitch change has occurred.
[0040]
In step S1130, the current wavelength B is set as a new average wavelength, and the number of matches D is set to “0”. On the other hand, in step S1140, the average wavelength is “average wavelength + (current wavelength−average wavelength) × 0.25”. Thus, in step S1140, a new average wavelength is obtained in consideration of the current wavelength while placing a weight on the previous average wavelength.
[0041]
Now, it is assumed that the initial values of the average wavelength, the current wavelength, and the number of coincidence are all “0”, and the wavelengths λ1, λ2, λ3,. The first current wavelength is λ1, the average wavelength A at that time, and the coincidence count D are both initial values “0”. If the absolute value of the difference between the average wavelength “0” and the current wavelength λ1 is not less than “1/16” (No in step S1120), the current wavelength λ1 is newly set as the average wavelength, and the number of matches D is set to “0”. The next current wavelength is λ2, and when the absolute value of the difference between the previous average wavelength λ1 and the current wavelength λ2 is less than “1/16” (Yes in step S1120), the average wavelength is set to “λ1 + (λ2− λ1) × 0.25 ”and the number of matches is“ 1 ”. As this process is repeated, as long as the absolute value of the difference between the current wavelength and the previous average wavelength is less than “1/16”, the number of matches is updated and the average wavelength is updated. Will go.
[0042]
Then, as shown in FIG. 12, when a low level signal is output as a comparison signal, it is determined whether or not the number of coincidences D exceeds a threshold value TC (step S1200). When it determines with not exceeding (No), the process part 64 skips the following processes. On the other hand, if it is determined that the frequency has exceeded (Yes), the process proceeds to step S1210. In step S1210, a signal indicating the obtained average wavelength is given to the oscillator 70, and then the variables A, B, and D are cleared for the next operation. At the same time, an initialization process for stopping the operation of the pitch detector 62 is performed.
[0043]
The oscillator 70 to which the signal is given in step S1210 generates a signal having a frequency corresponding to the average wavelength indicated by the signal and supplies the signal to the gate unit 80. As described above, when the comparison signal becomes a low level signal, the gate unit 80 gradually changes from the closed state to the open state, so that the mixer 90 causes the signal from the oscillator 70 to fade in to the musical sound signal. Can do. Thus, when a musical sound signal is played continuously, a sound having the same wavelength (same frequency) as that of the continuous sound is automatically added continuously.
[0044]
Therefore, according to the third embodiment, the comparator 40 outputs a comparison signal corresponding to the comparison result between the (amplitude) envelope signal generated by the envelope detection unit 10 and a preset threshold value, thereby detecting the wavelength. When the comparator 40 indicates that the musical tone signal is in a continuous state, the unit 60 obtains the wavelength of the fundamental tone and causes the oscillator 70 to generate a signal having a frequency corresponding to the obtained wavelength. When the signal generated by the oscillator 70 is supplied to the gate unit 80 and the gate is opened, the musical sound signal and the signal from the gate unit 80 are mixed by the mixer 90. Therefore, an effect can be automatically added to the musical tone signal if the musical instrument is played such that the musical tone signal is maintained at a specific wavelength.
[0045]
The pitch detector 62 determines that the musical tone signal is in a continuous state when a comparison signal indicating that the level of the envelope signal exceeds the threshold value is received, and sequentially obtains the fundamental sound length (pitch) of the musical tone signal. The processing unit 64 sequentially passes the processing to increase the number of coincidence when there is a predetermined relationship between the two obtained fundamental sound lengths, and the level of the envelope signal exceeds the threshold value. Until the comparison signal indicating that there is no signal is received, the number of coincidences D is continuously obtained, and only when the number of coincidences D exceeds the threshold value TC, the effect is added by operating the oscillator 70. It can be obtained with high accuracy.
[0046]
The gate unit 80 is gradually opened from the closed state in response to the reception of the comparison signal (low level signal) indicating that the level of the envelope signal does not exceed the threshold value. The signal from 70 can be faded in.
[0047]
As described above, according to each embodiment of the present invention, it is detected that the performance technique is special, and the effect is automatically added according to this detection. The effect addition instruction operation during performance by the operation means is not necessary, and real-time effect addition can be performed.
[0048]
Although the embodiments of the present invention have been described above, various modifications and changes can be made to the above-described embodiments without departing from the gist of the present invention. In addition, the configuration of the effect adding devices 100 to 101 can be realized by hardware such as a dedicated LSI as much as possible, and the function is realized by the CPU (or DSP) executing the operation program as much as possible. It is also possible.
【The invention's effect】
As described above, according to the present invention, there is an effect that it is possible to automatically add an effect to a musical sound signal by the playing method of a musical instrument.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of an effect adding device 100 according to a first embodiment.
FIG. 2 is an explanatory diagram of operations of an amplifier 22 and an offset adder 24;
FIG. 3 is an explanatory diagram of the operation of the envelope detector 10;
FIG. 4 is a configuration diagram of an effect adding device 101 according to a second embodiment.
FIG. 5 is an explanatory diagram of the operation of a threshold value setting unit 42 of the comparator 40.
6 is a schematic explanatory diagram of a rotary speaker 50. FIG.
FIG. 7 is an explanatory diagram of an operation of the second embodiment.
FIG. 8 is a configuration diagram of an effect adding device 102 according to a third embodiment.
9 is an explanatory diagram of the operation of the gate unit 80. FIG.
10 is an explanatory diagram of the operation of the comparator 40. FIG.
11 is a flowchart for explaining the operation of a processing unit 64. FIG.
12 is a flowchart for explaining the operation of a processing unit 64. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Envelope detector 12 Full wave rectification part 14 Integration part 20 Oscillator 22 Amplifier 24 Adder 26 Sine wave oscillation part 40 Comparator 42 Threshold setting part 50 Rotary speaker or rotary speaker simulator 60 Wavelength detection part 62 Pitch detection part 64 Processing Unit 70 oscillator 80 gate unit 90 mixer 52 control unit 100 effect adding device 101 effect adding device 102 effect adding device

Claims (2)

A device for adding an effect to a musical tone signal from a musical instrument,
Envelope detecting means for generating an amplitude envelope signal based on the musical sound signal;
A comparison means for outputting a comparison signal according to a comparison result between the generated amplitude envelope signal and a preset threshold value;
Gate means for opening and closing in response to the comparison signal;
Mixing means for mixing the musical sound signal and the signal from the gate means;
Wavelength detection means for determining the wavelength of the fundamental tone when the comparison signal indicates that the musical tone signal is in a sustained state;
A signal generating means for generating a signal having a frequency according to the obtained wavelength;
The signal generated by the signal generating means is configured to be supplied to the gate means,
The wavelength detecting means includes
Means for sequentially determining the tone length of the tone signal by determining that the tone signal is in a sustained state when a comparison signal indicating that the level of the amplitude envelope signal exceeds the threshold value is received;
Looking at the sequentially obtained fundamental wave lengths on the time axis, both the current wavelength, which is the newest fundamental wave length, and the current average wavelength, which has been updated using the fundamental wave length previously obtained, are both displayed. When the absolute value of the difference between wavelengths is less than 1/16, a process of sequentially increasing the number of matches is received, and a comparison signal indicating that the level of the amplitude envelope signal does not exceed the threshold value is received Means to continue repeatedly until
See containing and means for the operation of the signal generating the said signal generating means only when the excess of number of matches threshold value which this match count is preset,
The average wavelength update is
If the absolute value of the difference between the previous current wavelength (B) one previous to the current current wavelength and the previous average wavelength (A) with respect to the previous current wavelength is less than 1/16, “A + While the value obtained by the calculation of (B−A) × 0.25 ”is used as the current average wavelength for the current increase determination process of the number of matches,
In other cases, the effect adding device is characterized in that the previous current wavelength (B) itself is used as the current average wavelength for the current increase determination process of the number of matches . In the effect addition apparatus of Claim 1,
The gate means includes
An effect adding apparatus, wherein the apparatus is configured to gradually open from a closed state in response to reception of a comparison signal indicating that the level of the amplitude envelope signal does not exceed the threshold value.

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