JP2016151628A - Music signal processing device and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a music signal processing device and a program in which when a chord is inputted and pitch detection fails, avoidance is achieved free of a player's sense of discomfort.SOLUTION: The music signal processing device has: a pitch information processing circuit 40 for detecting a pitch from a music signal obtained by a pickup 5 and also outputting pitch detection success information indicating success or failure in pitch detection; a distortion signal generation circuit 35 for inputting the music signal obtained by the pickup 5 and generating a distortion signal based on it; an oscillator 30 for generating an oscillation signal corresponding to the pitch detected by the pitch information processing circuit 40; and an output control circuit for outputting the oscillation signal generated by the oscillator 30 when the pitch detection success information indicates that pitch detection is "Yes," or outputting the distortion signal generated by the distortion signal generation circuit 35 when the pitch detection success information indicates that pitch detection is "No."SELECTED DRAWING: Figure 1

Description

  The present invention relates to an apparatus for processing a musical tone signal of an electronic stringed instrument, and more particularly to an apparatus and a program for performing processing when a pitch detection error occurs in a guitar synthesizer that drives an oscillator based on a pitch detected from a musical tone signal of an electronic guitar. .

  Conventionally, what is called a “guitar synthesizer” has been proposed. This guitar synthesizer is a device that generates a synthesizer sound by driving an oscillator based on a pitch corresponding to a tone signal picked up by a pickup provided in a main body of an electronic guitar (electric guitar, electric guitar). is there. In other words, this guitar synthesizer detects the pitch from the string vibration signal (electric signal obtained based on the string vibration by the player's string operation) detected by the pickup provided in the body of the electronic guitar, and this detection. The synthesizer sound is output by driving the synthesizer sound source based on the pitch that has been generated. Many applications have been filed for this guitar synthesizer (see Patent Document 1 and Patent Document 2).

  In addition, in order to apply to a guitar synthesizer, a first pickup and a second pickup are provided at both ends of the picking range of the electronic guitar as countermeasures for erroneous detection of pitch detection based on the string vibration signal of the electronic guitar. Things have been proposed. According to this apparatus, when the pitch information obtained from each of the two pickups does not match, the pitch information detected from the output of the first pickup is output as the first method (speed priority mode). In addition, the second method (accuracy priority mode) waits until the same pitch information is detected at least twice and tries to output the pitch information (see Patent Document 3). In this way, pitch detection is performed more accurately and quickly than in the past.

JP-A-9-127951 (page 2-3, FIG. 1) JP-A-9-288482 (page 2-4, FIG. 1) Japanese Patent Laid-Open No. 9-244634 (page 1-4, FIG. 1)

  However, in a conventional guitar synthesizer, when a player plays multiple strings of an electronic guitar simultaneously, that is, when playing a chord, the pitch detection of the output signal of the electronic guitar may fail even if strict measures are taken. is there. The configuration of the device in such a case is a large-scale one with pickups prepared for each of the multiple strings of the electronic guitar, or an unintended pitch sound is output when pitch detection fails. For this reason, there is an inconvenience that it is necessary to stop the tone output, and it is necessary to overcome such an inconvenience.

  The present invention has been made to solve such a conventional problem, and even when chords are input and pitch detection fails and pitch destruction occurs, avoiding the player from feeling uncomfortable. An object of the present invention is to provide a musical sound signal processing apparatus and program for performing the above.

  In order to achieve the above object, the present inventor shall be configured to distort and output an input signal instead of a signal derived from an oscillator of a guitar synthesizer when pitch detection fails or is difficult. That is, it has been found that it can be handled by a signal derived from an input signal.

That is, the present invention is an apparatus (100) for processing a musical sound signal of an electronic guitar (110) provided with a pickup (5) for capturing a string vibration signal by a string operation.
Pitch information processing means (40) for performing pitch detection from a musical sound signal obtained by the pickup and outputting pitch detection success / failure information indicating success or failure of pitch detection;
A distortion signal generation means (35) for inputting the musical sound signal obtained by the pickup and generating a distortion signal based on the music signal;
An oscillator (30) for generating an oscillation signal corresponding to the pitch detected by the pitch information processing means;
When the pitch detection success / failure information is information that positively detects the pitch, the oscillation signal generated by the oscillator is output, while the pitch detection success / failure information is information that rejects the pitch detection. Comprises output control means for outputting a distortion signal generated by the distortion signal generation means.

According to the present invention, the pitch information processing means (40) performs pitch detection from a musical sound signal obtained by a pickup provided in the electronic guitar (110) and outputs pitch detection success / failure information indicating success or failure of the pitch detection. . The output control means outputs the oscillation signal generated by the oscillator (30) that generates the oscillation signal according to the pitch when the pitch detection success / failure information is information that sets the detection of the pitch to “positive”. If the pitch detection success / failure information is information indicating that the pitch detection is “No”, the musical tone signal is input, and the distortion signal generated by the distortion signal generation means (35) is output based on the musical sound signal.

Therefore, even when the player of the electronic guitar (110) plays a chord and the pitch cannot be detected from the musical tone signal, the distortion signal (distortion waveform) generated by the distortion signal generation means (35) is output. This distortion signal is not a signal oscillated by the oscillator (30) whose output becomes unstable when no pitch is detected, that is, a signal derived from the input signal, not a signal derived from the oscillator constituting the guitar synthesizer. A signal derived from the input signal performed by the person is output. Therefore, even when a chord is input and pitch detection fails, it is possible to avoid it without making the player feel uncomfortable. Of course, if the supply of the pitch data to the oscillator (30) is suddenly stopped, there is a sense of incongruity.

  Further, it is preferable that the pitch detection success / failure information is 1-bit information because the apparatus scale can be reduced. Further, the output control means includes a first multiplier (42) whose coefficient is zero when the 1-bit pitch detection success / failure information is information indicating that the pitch detection is “NO”, and the 1-bit A NOT circuit (46) for inverting the pitch detection success / failure information, and a second multiplier (44) that sets the coefficient to zero when the output of the NOT circuit is information that makes the pitch success / failure information "No". And an adder (48) for adding the output of the first multiplier and the output of the second multiplier.

  According to this configuration, the first multiplier (42) sets the coefficient to zero when the 1-bit pitch detection success / failure information is information indicating that the pitch detection is “No” (for example, “0”). Although the output of the oscillator (30) is invalidated, in this case, the output of the NOT circuit (46) inverts the 1-bit information that is “No” (for example, “1”), that is, the pitch detection. Therefore, the output of the distortion signal generation means (35) remains the same. On the other hand, when the 1-bit detection success / failure information is information that sets the pitch detection to “positive” (for example, “1”), the first multiplier (42) sets a normal coefficient. In this case, since the oscillation signal of the oscillator (30) is output as it is, the output of the NOT circuit (46) becomes information indicating that the detection of the pitch is "No", so that the distortion signal generating means (35) Output is disabled.

  Therefore, according to this configuration, the output change control according to the contents of the pitch success / failure information, that is, the oscillator, is performed by an extremely small digital circuit including a pair of multipliers, one logic circuit, and one adder. It is possible to perform output change control with the distortion signal generation means.

Another aspect of the present invention is an apparatus (200) for processing a musical tone signal of an electronic guitar (110) equipped with a pickup (11) that captures a string vibration signal by a string operation.
The musical tone signal obtained by the pickup (11) is divided into a first input signal and a second input signal, and is input.
An adder (12) for outputting an addition signal obtained by adding the first input signal and the second input signal;
Pitch information processing means (40) for performing pitch detection from the addition signal and outputting pitch detection success / failure information indicating success or failure of the pitch detection;
Distortion signal generation means (35) for inputting the addition signal and generating a distortion waveform signal based on the input signal;
An oscillator (30) for generating an oscillation signal corresponding to the pitch detected by the pitch information processing means;
An output control means for outputting an oscillation signal generated by the oscillator, or for outputting a distortion signal generated by the distortion signal generation means;
First amplitude determining means (80) for outputting first information when the first input signal exceeds a first threshold;
Second amplitude determining means (85) for outputting second information when the second input signal exceeds a second threshold;
Amplitude information output means for outputting third information when the first information and the second information are both predetermined values;
When the pitch detection success / failure information is information for rejecting pitch detection and the amplitude information output means outputs the third information, the distortion signal generated by the distortion signal generation means (35). Is output.

According to this invention, the pitch information processing means (40) performs pitch detection from the addition signal obtained by adding the first input signal and the second input signal by the adder (12), and the success or failure of the pitch detection. Pitch detection success / failure information indicating is output. Further, the first amplitude determining means (80) and the second amplitude determining means (85) are configured such that the first input signal and the second input signal obtained by dividing the musical sound signal obtained by the pickup (11) are respectively the first input signal and the second input signal. When the second threshold value is exceeded, the first and second information (for example, “1” of 1 bit) is output. The amplitude information output means receives these outputs, and outputs the third information when the first information and the second information are both predetermined values. Further, the output control means outputs the oscillation signal generated by the oscillator, or outputs the distortion signal generated by the distortion signal generation means. When the pitch detection success / failure information is information for rejecting pitch detection, or when the amplitude information output means outputs third information (for example, 1-bit “0”), or both In this case, the distortion signal generated by the distortion signal generation means (35) is output. In other cases, the oscillation signal of the oscillator (30) is output. Both cases are cases where the pitch detection success / failure information is information for rejecting pitch detection, and the amplitude information output means outputs the third information. The following means both.

Therefore, even if the player of the electronic guitar plays a chord, even if the pitch processing means finds periodicity and the pitch detection success / failure information is “positive”, the distortion signal generating means ( The distortion waveform generated in step 35) is output. Moreover, the output of the distortion waveform is performed only when the pitch detection success / failure information is information indicating that the pitch detection is “no” and the amplitude determination means outputs the third information. That is, only when the first input signal (input 1) and the second input signal (input 2) exceed the first and second thresholds, in other words, the first input signal (input If both 1) and the second input signal (input 2) are played with strings being played, or if the pitch detection success / failure information indicates that the pitch detection is “NO”, or both In this case, a distortion signal is output, so that the distortion signal can be output in a state in which more accurate chord detection is possible.

This distortion signal is not a signal oscillated by the oscillator (30) whose output becomes unstable when the pitch is not detected, that is, a signal derived from the performance of the performer, not a signal derived from the oscillator constituting the guitar synthesizer. . Therefore, even when chords are input and pitch detection fails, it is possible to avoid the chord without making the player feel uncomfortable.

In addition, the first amplitude determining means includes
A first envelope detector (70) that detects and outputs an envelope of the first input signal; and an output result of the first envelope detector exceeds the first threshold. A first signal processing unit (80) for outputting information,
The second amplitude determining means includes
A second envelope detector (75) for detecting and outputting an envelope of the second input signal, and the second envelope detector when the output result of the second envelope detector exceeds the second threshold. A second signal processing unit (85) for outputting information,
The amplitude information output means includes
A logical product circuit (90) that takes a logical product with the output of the first signal processing unit and the output of the second signal processing unit as inputs, and
The first information and the second information both have the same logic and are different from the third information, and are 1-bit information.

  According to this configuration, the first and second envelope detectors (70, 75) detect and output the envelopes of the first and second input signals, respectively. Further, when the output results of the first and second envelope detection units (70, 75) exceed the first and second threshold values, respectively, in the first and second signal processing units (80, 85). The first and second information are output. The logical product circuit (90) takes a logical product with the output of the first signal processing unit and the output of the second signal processing unit as inputs. The first and second information both have the same logic and are different from the third information, and the first to third information is 1-bit information.

  Therefore, each of the first and second amplitude determining means may have a circuit configuration that only detects the envelopes of the first and second input signals and determines whether or not each exceeds the respective thresholds, The amplitude information output means only needs to take a logical product. Moreover, since the first to third predetermined information is a 1-bit logical value, it can be handled with a small and simple logic circuit configuration.

According to still another aspect of the present invention, an oscillator (30) that processes a musical tone signal of an electronic guitar provided with a pickup (5) that captures a string vibration signal by a string operation and generates an oscillation signal corresponding to the detected pitch. ) Is a program for operating the musical sound signal processing device (100),
A pitch information processing function for performing pitch detection from a musical tone signal obtained by the pickup (5) and outputting pitch detection success / failure information indicating success or failure of pitch detection;
A distortion signal generation function for inputting the musical sound signal obtained by the pickup (5) and generating a distortion waveform signal based thereon;
When the pitch detection success / failure information is information that positively detects the pitch, the oscillation signal generated by the oscillator (30) is output, while the pitch detection success / failure information is information that rejects the pitch detection. In some cases, the program is a program for realizing in a computer an output control function for outputting the distortion signal generated by the distortion signal generation function.

When this program (recorded on a recording medium such as a ROM) is executed by a processor such as a CPU or DSP,
A pitch information processing function for performing pitch detection from a musical tone signal obtained by the pickup (5) and outputting pitch detection success / failure information indicating success or failure of the pitch detection;
A distortion signal generation function for inputting the musical sound signal obtained by the pickup (5) and generating a distortion signal based thereon;
When the pitch detection success / failure information is information that positively detects the pitch, the oscillation signal generated by the oscillator (30) is output, while the pitch detection success / failure information is information that rejects the pitch detection. In some cases, an output control function for outputting the distortion signal generated by the distortion signal generation function is realized in a computer.

The pitch information processing function performs pitch detection from a musical tone signal obtained by the pickup (5) provided in the electronic guitar (110) and outputs pitch detection success / failure information indicating success or failure of the pitch detection. The output control function outputs the oscillation signal generated by the oscillator (30) that generates the oscillation signal corresponding to the pitch when the pitch detection success / failure information is information that sets the detection of the pitch to “positive”. If the pitch detection success / failure information is information indicating that the pitch detection is “NO”, a distortion signal generated by a distortion signal generation function that inputs a musical sound signal and generates a distortion signal based on the musical sound signal is output.

Therefore, even if the player of the electronic guitar (110) plays a chord and inputs it and the pitch cannot be detected from the musical tone signal, a distorted waveform is output. This distorted waveform is not a signal oscillated by the oscillator (30) whose output becomes unstable when the pitch is not detected, that is, a signal derived from the performance of the performer, not a signal derived from the oscillator constituting the guitar synthesizer. . Therefore, even when a chord is input and pitch detection fails, the avoidance can be performed without causing the player to feel uncomfortable.

  By recording such a program on a recording medium such as a ROM and reading and executing the recorded program by a processor such as a CPU or DSP, each function such as a pitch information processing function is realized. Is possible.

According to the present invention, even if a chord is input and pitch detection fails, it is possible to realize a musical tone signal processing apparatus and program that can perform avoidance without making the player feel uncomfortable. Is obtained.

1 is a configuration diagram of a musical sound signal processing apparatus 100. FIG. It is typical explanatory drawing of a structure of the electronic stringed instrument 110 (electronic guitar). 2 is a hardware configuration diagram of the musical tone signal processing apparatus 100. FIG. 5 is a schematic explanatory diagram of a pitch detection operation of the pitch information processing circuit 40. FIG. 6 is a schematic explanatory diagram of the operation of the distortion signal generation circuit 35. FIG. 1 is a configuration diagram of a musical sound signal processing device 200. FIG. 2 is a configuration diagram of a musical tone signal processing device 210. FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of the tone signal processing 100 of the first embodiment of the present invention, and FIG. 3 is a hardware block diagram thereof. Note that there is no difference in the hardware configuration even in the second embodiment.

(First embodiment)
(Constitution)
As shown in FIG. 1, the musical sound signal processing 100 is an analog / digital converter that inputs a musical sound signal picked up by a pickup 5 provided on a body that is a main body of an electronic guitar (electric guitar, electric guitar) and performs analog / digital conversion. D converter 10, various signal processing circuits, filter circuit 50 for filtering the output result of this signal processing circuit, D / A converter 20 for digital-to-analog conversion of this filtering result, and this digital-analog conversion And a speaker (SP) 60 for emitting an analog signal. As the filter circuit 50, a low-pass type is usually employed to smooth the signal, but it may be a band-pass type or a high-pass type.

  Examples of the signal processing circuit include a pitch information processing circuit 40, an oscillator 30, a distortion signal generation circuit 35, and an output control circuit. The output control circuit includes a pair of multipliers 42 and 44, a NOT circuit 46, and an adder 48 that adds the output results of the pair of multipliers 42 and 44. The output is input to the filter circuit 50.

The pickup 5 is a sensor that takes in a string vibration signal, which is an electric signal of string vibration generated by the player's string operation, and is provided on the body of the electronic guitar. The simple structure of the electronic guitar will be described later. The pitch information processing circuit 40 performs pitch detection from a musical tone signal (performance sound of an electronic guitar) obtained by the pickup 5 and outputs pitch detection success / failure information indicating success or failure of the pitch detection. In order to reduce the size of the apparatus, the pitch detection success / failure information is 1-bit information. Specifically, when the pitch is detected, that is, when the pitch detection success / failure information is “positive”, it is “1”. On the other hand, when the pitch is not detected, that is, the pitch detection success / failure information is “No”. In this case, it is “0”.

  FIG. 4 is a schematic explanatory diagram of the pitch detection operation. As shown in FIG. 4A, when a signal A composed of waves having the same length on the time axis of one wavelength is input with the horizontal axis as the time axis t, the pitch information processing circuit 40 has one cycle. The period is detected every time, and the target period T1 and the next period T2 are detected and compared. If the length of the period is “T1≈T2,” the pitch detection success information is “pitch detection OK”. "Correct: 1" is output. On the other hand, as shown in FIG. 4 (b), if a signal B consisting of a repetitive mountain-valley wave having an irregular length on the time axis of one wavelength is input, the pitch information processing circuit 40 The period is detected for each period, and the period T1 of interest and the next period T2 are detected and compared. Since the period length is “T1 ≠ T2,” the pitch detection success / failure information “ "No: 0" is output. In this way, the pitch detection and non-detection are determined by detecting and comparing the period of the signal of interest and the next period.

  The distortion signal generation circuit 35 receives a musical sound signal of an electronic guitar obtained by the pickup 5 and analog-digital converted by the A / D converter 10 and generates a distortion signal (distortion waveform) based on the music signal. FIG. 5 is an explanatory diagram of the operation of generating a distortion signal, and “t” on the horizontal axis indicates the time axis. The sine wave input signal A shown in FIG. 5A is amplified by an amplifier whose amplification factor is set to be considerably large, and becomes an amplified waveform B. Next, the upper and lower sides of the amplified waveform B are clipped to generate a distortion signal C. That is, the input signal A is amplified to obtain an amplified signal B, which is clipped into a distorted waveform C, and this amplification factor is set to a considerably large value.

  The oscillator 30 generates an oscillation signal corresponding to the pitch detected by the pitch information processing circuit 40. Since the pitch information processing circuit 40 is configured to detect the pitch from the musical tone signal of the electronic guitar picked up by the pickup 5 and drive the oscillator 30 based on the detected pitch, the pickup 5, the pitch information processing circuit 40, and the oscillator 30 are configured. Constitutes a guitar synthesizer.

  When the 1-bit pitch detection success / failure information is information (“0”) indicating that the pitch detection is “NO”, the output control circuit includes a multiplier 42 that sets the coefficient to zero “0”, and the 1-bit pitch detection success / failure information. A NOT circuit 46 for inverting the pitch detection success / failure information, a multiplier 44 for setting the coefficient to zero “0” when the output of the NOT circuit 46 is “no” for the pitch success / failure information, and a multiplier 42 And an adder 48 for adding the output of the multiplier 44 to the output of the multiplier 44. The multiplier 42 and the multiplier 44 set the coefficient to “0” when the coefficient signal given to itself is “0”, and set the coefficient to “0” when the coefficient signal given to itself is “1”. “1”. The multiplier 42 and the multiplier 44 perform normal multiplication operation when their own coefficient is “1”, but invalidate the input signal when their coefficient is “0”. The normal coefficient is not always “1”.

  When the pitch detection information is “1”, the coefficient signal of the multiplier 42 is “1”, the operation of the multiplier 42 is the normal operation, and the oscillation signal from the oscillator 30 is output. At this time, the output of the NOT circuit 46 becomes “0”, and the multiplier 44 multiplies the output of the distortion signal generation circuit 35 by “0”, so that the distortion signal output from the distortion signal generation circuit 35 is invalidated. .

  On the other hand, when the pitch detection success / failure information is “0”, the output of the NOT circuit 46 is “1”, the operation of the multiplier 44 is the normal operation, and the distortion signal is output from the distortion signal generation circuit 35. . At this time, the coefficient of the multiplier 42 is “0”, and the oscillation signal from the oscillator 30 is multiplied by “0”, so that the oscillation signal from the oscillator 30 is invalidated. In this way, the output control circuit outputs the oscillation signal generated by the oscillator 30 when the pitch detection success / failure information is information indicating that the pitch detection is “positive”, while the pitch detection success / failure information indicates the pitch detection success / failure information. In the case of information indicating “no” as the detection, the distortion signal generated by the distortion signal generation circuit 35 is output.

  Therefore, a simple digital circuit including a pair of multipliers 42 and 44, a single NOT circuit 46, and an adder 48, and the oscillator 30 and the distortion signal generation means 35 according to the contents of 1-bit pitch detection success / failure information. Output change control is possible.

(Hardware configuration)
FIG. 3 is a hardware configuration diagram of the musical tone signal processing apparatus 100. The hardware includes a pickup 5, a CPU 120, a ROM 130, a RAM 135, an A / D converter 10, a D / A converter 20, an oscillator 30, and a distortion signal generation circuit 35. Each component is configured to be able to communicate required information with each other via a bus 145. The CPU 120 reads the program from the ROM 130 which is a recording medium on which an operation program, data, and the like are recorded, and executes the program. Thereby, various functions of the apparatus are realized. At this time, the RAM 135 is formed with a temporary storage area or the like in the calculation process in which the CPU 120 executes the operation program.

  The distortion signal generation circuit 35 that generates a distortion signal based on the input musical sound signal and the oscillator 30 that outputs an oscillation signal may be configured as hardware, but a processor such as a DSP or CPU performs signal processing by software. It can also be realized by doing. That is, each circuit in FIG. 1 can also be realized by executing a program recorded in the ROM 130 by a processor such as a CPU or DSP.

(Configuration of electronic guitar)
FIG. 2 is a schematic configuration diagram in the vicinity of the main body of an electronic guitar 110 as an example of an electronic stringed instrument. The electronic guitar 110 includes a body 3 as a main body, a neck 6 connected to the body 3 and provided with frets in the extending direction thereof, and a head (not shown). FIG. 2 schematically shows a configuration in which the electronic guitar 110 is cut along the breaking line A for ease of explanation. A bridge 3 is provided at the lower center of the body 3, and one end side of six strings G is fixed to the brig 3, and the other end side of the string G is fixed to the head, and the string G is stretched. It is installed. For example, a magnet type pickup 5 is provided on the neck 6 side of the bridge 4 so that the string vibration caused by the string operation of the string G is picked up as an electric signal and input to the musical tone signal processing apparatus 100 shown in FIG. It is configured.

  Below the body 3, an output terminal 7 for outputting a performance signal, a tone adjustment button 8 for changing the tone, and a volume 9 for adjusting the volume are provided. In this embodiment, a tone signal processing device 100 for inputting a signal from the pickup 5 and processing the signal is mounted on the back side of the body 3. The shape of the body 3, the type and shape of the pickup 5, the mounting position of the musical tone signal processing device 100, and the like can be changed as appropriate. Also, a monitor terminal for outputting a signal of the musical tone signal processing apparatus 100 can be set as appropriate. Thus, a string vibration signal corresponding to the string vibration caused by the string operation is input from the pickup 5, and the input electronic guitar sound is signal-processed.

(Operation)
Next, the operation of the musical tone signal processing apparatus 100 will be described. The string vibration signal picked up by the pickup 5 provided on the surface of the body 3 which is the main body of the electronic guitar 110 is input as a musical sound signal and is converted from analog to digital by the A / D converter 10. The analog-digital converted musical sound signal is input to the pitch information processing circuit 40 and the distortion signal generation circuit 35.

  The pitch information processing circuit 40 attempts to detect the pitch as described above based on the input digital musical tone signal. As a result, when the pitch is detected, the information on the detected pitch is transmitted to the oscillator 30 as pitch data, and 1-bit information indicating that the pitch has been detected (OK) as the pitch detection success / failure information. 1 "is output. On the other hand, if the pitch does not become a fixed value after a plurality of predetermined times, the pitch data is not stable. At this time, the pitch information processing circuit 40 outputs “0” which is 1-bit information indicating that the pitch cannot be detected (NG) as the pitch detection success / failure information.

  When the pitch detection success / failure information is “1”, the output of the NOT circuit 46 is “0”, and the multiplier 44 is given the coefficient signal “0”, so that the coefficient is “0”, and the distortion signal The distortion signal from the generation circuit 35 is multiplied by “0” and its output is invalidated. On the other hand, when the pitch detection success / failure information is “0”, the multiplier 42 is given the coefficient signal “0”, so the coefficient is “0”, and the oscillation signal from the oscillator 30 is “0”. Is multiplied and the output is invalidated. Thus, when the pitch detection success / failure information is information (“1” in this example) that makes the pitch detection “positive”, the oscillation signal generated by the oscillator 30 is output, while the pitch detection success / failure information is the pitch detection success / failure information. When the information is “No” for detection (“0” in this example), the distortion signal generated by the distortion signal generation circuit 35 is output.

As described above, according to the first embodiment, the pitch information processing circuit 40 performs pitch detection from the musical sound signal obtained by the pickup 5 provided in the electronic guitar 110 and indicates success or failure of the pitch detection. Outputs pitch detection success / failure information. When the pitch detection success / failure information sets the pitch detection to “positive”, the output control circuit outputs the oscillation signal generated by the oscillator 30 that generates the oscillation signal corresponding to the pitch, while the pitch detection success / failure information If the pitch detection is “NO”, the musical tone signal is input, and the distortion signal generated by the distortion signal generation circuit 35 that generates the distortion signal based on this is output.

Therefore, even if the player of the electronic guitar plays a chord and inputs it and the pitch cannot be detected from the musical tone signal, the distortion signal generated by the distortion signal generation circuit 35 is output. This is not a signal oscillated by the oscillator 30 whose output becomes unstable when no pitch is detected. This distortion signal is not a signal derived from the oscillator 30 constituting the guitar synthesizer but a waveform derived from the input signal. In other words, a signal derived from this input signal is output, and even when a chord is input and pitch detection fails, it is possible to avoid it without making the player feel uncomfortable. . Of course, if the supply of the pitch data to the oscillator 30 is suddenly stopped, there is a sense of incongruity.

(Second Embodiment)
(Constitution)
FIG. 6 is a block diagram of a musical tone signal processing apparatus 200 according to the second embodiment of the present invention. This embodiment is characterized in that the detection accuracy of the chord time is improved. The musical tone signal processing apparatus 200 is configured to separately input a musical tone signal obtained by the pickup 11 into a first input signal (input 1) and a second input signal (input 2). For example, the pickup 11 is a piezo type, and a signal (first input signal) obtained from the first to third strings is input to the A / D converter 10 and is obtained from the fourth to sixth strings. The signal (second input signal) is used as the input of the A / D converter 15.

  The musical tone signal processing apparatus 200 also outputs an adder 12 that outputs an addition signal obtained by adding the first input signal and the second input signal, and detects the pitch from the addition signal and indicates the success or failure of the pitch detection. A pitch information processing circuit 40 that outputs detection success / failure information, a distortion signal generation circuit 35 that inputs an addition signal and generates a distortion waveform signal based on the addition signal, and an oscillation signal corresponding to the pitch detected by the pitch information processing circuit 40 That outputs an oscillation signal generated by the oscillator 30, or an output control circuit that outputs a distortion signal generated by the distortion signal generation circuit 35, and a filter that inputs and filters the output of this circuit A circuit 50, a D / A converter 20 for digital-to-analog conversion of the filtering result, and a speaker for emitting the analogized signal. (SP) has a 60.

Further, the musical tone signal processing apparatus 200 receives an output of the A / D converter 10 and detects an envelope (ENV1 signal) and outputs an envelope (ENV1 signal), and an output of the envelope detection circuit 70. The ENV1 signal processing circuit 80 (first signal processing unit) that outputs “1” (first predetermined value) when the result exceeds the first threshold, and the output signal of the A / D converter 15 An envelope detection circuit 75 (second envelope detection unit) that inputs and detects and outputs an envelope (ENV2 signal), and “1” (second output) when the output result of the envelope detection circuit 75 exceeds the second threshold value ENV2 signal processing circuit 85 (second signal processing unit) that outputs a predetermined value). Here, when there is a difference in the input level between the input 1 and the input 2, the first threshold value and the second threshold value may be set individually.

Furthermore, an AND circuit 90 that performs an AND operation using the output of the ENV1 signal processing circuit 80 and the output of the ENV1 signal processing circuit 85 as inputs, and a NOT circuit 92 that outputs an inversion of the output of the AND circuit 90 is provided. Yes. The AND circuit 94 receives the pitch detection success / failure information and the output of the NOT circuit 92 as inputs and outputs a logical product of these. The circuit scale can be reduced by using the output of the ENV1 signal processing circuit 80 or the ENV1 signal processing circuit 85 as 1-bit information.

(Operation)
Next, the operation of the musical tone signal processing apparatus 200 will be described. The string vibration signal picked up by the pickup 11 provided on the surface of the body 3 which is the main body of the electronic guitar 110 is inputted as a musical sound signal, and is analogized by each of the A / D converter 10 and the A / D converter 15. Digitally converted. In this configuration example, the musical tone signals generated by operating the first to third strings are input from the pickup portion corresponding to the first to third strings, and are converted from digital to analog by the A / D converter 10, and the fourth to sixth are selected. The tone signal generated by the operation of the second string is input from the pickup portion corresponding to the fourth to sixth strings and is converted from digital to analog by the A / D converter 15.

The musical sound signal digitized by the A / D converter 10 is input to the envelope detection circuit 70, and the musical sound signal digitized by the A / D converter 15 is input to the envelope detection circuit 75. The tone signal digitized by the A / D converter 10 and the tone signal digitized by the A / D converter 15 are added by the adder 12. The addition result of the adder 12 is input to the pitch information processing circuit 40 and the distortion signal generation circuit 35.

  The pitch information processing circuit 40 attempts to detect the pitch as described above based on the input digital musical tone signal. As a result, when the pitch is detected, the information on the detected pitch is transmitted to the oscillator 30 as pitch data, and 1-bit information indicating that the pitch has been detected (OK) as the pitch detection success / failure information. 1 "is output. On the other hand, if the pitch does not become a fixed value after a plurality of predetermined times, the pitch data is not stable. At this time, the pitch information processing circuit 40 outputs “0” which is 1-bit information indicating that the pitch cannot be detected (NG) as the pitch detection success / failure information.

  Next, when the pitch detection success / failure information is “1”, the output of the NOT circuit 46 is “0”, and the multiplier 44 is given the coefficient signal “0”, so the coefficient is “0”. The distortion signal from the distortion signal generation circuit 35 is multiplied by “0” and its output is invalidated. On the other hand, when the pitch detection success / failure information is “0”, the multiplier 42 is given the coefficient signal “0”, so the coefficient is “0”, and the oscillation signal from the oscillator 30 is “0”. Is multiplied and the output is invalidated. Thus, when the pitch detection success / failure information is information (“1” in this example) that makes the pitch detection “positive”, the oscillation signal generated by the oscillator 30 is output, while the pitch detection success / failure information is the pitch detection success / failure information. When the information is “No” for detection (“0” in this example), the distortion signal generated by the distortion signal generation circuit 35 is output.

The envelope detection circuit 70 and the envelope detection circuit 75 detect the envelope of the input signal, and output this to the ENV1 signal processing circuit 80 and the ENV2 signal processing circuit 85, respectively. Next, the ENV1 signal processing circuit 80 and the ENV2 signal processing circuit 85 respectively determine whether or not the input envelope signal ENV1 signal and ENV2 signal exceed the first threshold value and the second threshold value. The ENV1 signal processing circuit 80 and the ENV2 signal processing circuit 85 output “1” when it is determined that the input signals ENV1 and ENV2 have exceeded the corresponding threshold values, and “0” otherwise. . The AND circuit 90 takes a logical product with the outputs of the ENV1 signal processing circuit 80 and the ENV2 signal processing circuit 85 as inputs, and the output is inverted by a NOT circuit 92. That is, only when the input 1 and the input 2 exceed the first and second threshold values, respectively, in other words, the first input signal (input 1) and the second input signal (input 2) described above. )), The NOT circuit 92 becomes “0” only when the string is played and played.

The AND circuit 94 takes a logical product of the pitch detection success / failure information and the NOT circuit 92 and outputs the logical product. That is, even if the pitch detection success / failure information is “1”, if the output of the NOT circuit 92 is not “0”, a distortion signal is output from the distortion signal generation circuit 35 corresponding to the input of the chord. Therefore, the detection accuracy for the chord time is improved.

As described above, according to the second embodiment, the pitch information processing circuit 40 performs pitch detection from the addition signal obtained by adding the first input signal and the second input signal by the adder 12 and the pitch. Outputs detection success / failure information. Further, the first ENV1 signal processing circuit 80 and the ENV2 signal processing circuit 85 are such that the first input signal and the second input signal obtained by dividing the musical tone signal obtained by the pickup 11 exceed the first and second threshold values, respectively. “1” is output when the output is “0”, and the AND circuit 90 receives this output and outputs “1” when both are “1”. And, when the pitch detection success / failure information is “0”, in which the detection of the pitch is “No”, or when the output of the NOT circuit 92 obtained by inverting the AND circuit 90 outputs “0”, Alternatively, when both are “0”, it becomes “0” and the NOT circuit 46 outputs “1”, so that the distortion signal generated by the distortion signal generation circuit 35 is output.

Therefore, even when the player of the electronic guitar plays a chord, even if the pitch information processing circuit 40 makes the detection of the pitch “positive” from the musical tone signal, the distortion signal generation circuit 35. The distortion signal generated by is output. When the pitch detection success / failure information indicates that the pitch is detected as “No”, or when the input 1 and the input 2 exceed the first and second threshold values, respectively, or both, a distortion signal is output. Therefore, it is possible to output a distortion signal by more accurate chord detection.

(Modification)
FIG. 6 is a configuration diagram of a modification of the second embodiment. The difference is that a signal control circuit 150 is provided instead of the “ENV1 signal processing circuit 80, ENV2 signal processing circuit 85, AND circuit 90, NOT circuit 92” shown in FIG. If the signal control circuit 150 has a function of outputting “0” when both the ENV1 signal and the ENV2 signal are “1”, the “ENV1 signal processing circuit 80, ENV2 signal shown in FIG. It has the same function as a series of processing circuit 85, AND circuit 90, and NOT circuit 92 ". The signal control circuit 150 can be realized, for example, by making a custom IC or changing a program executed by the CPU 120. In this way, a part of the musical sound signals 100 and 200 of the present embodiment can be appropriately integrated and realized by hardware or software.

  The operation of the musical tone signal processing devices 100 and 200 as described above can be realized by the CPU 120 executing a program for device operation recorded in the ROM 130. Moreover, various modifications are mentioned in the above embodiment. For example, the number of strings of the electronic guitar may be other than six, the clipping position at the time of distortion signal generation may be changed, the type of pickup may be changed, and the scope of the present invention is described here It goes without saying that it is not only.

  As described above, the musical sound signal processing apparatus of the present invention can be applied to the music field, particularly to an electronic guitar.

5 Pickup 10 A / D Converter 11 Pickup 12 Adder 15 A / D Converter 20 D / A Converter 30 Oscillator 35 Distortion Signal Generation Circuit 42 Multiplier 44 Multiplier 46 NOT Circuit 48 Adder 50 Filter Circuit 70 Envelope Circuit 75 Envelope circuit 80 ENV1 signal processing circuit 85 ENV2 signal processing circuit 90 AND circuit 92 NOT circuit 94 AND circuit 100 Music signal processing device 110 Electronic stringed instrument (electronic guitar)
150 signal processing circuit 200 music signal processing device 210 music signal processing device

Claims (6)

An apparatus for processing a musical tone signal of an electronic guitar equipped with a pickup for capturing a string vibration signal by string operation,
Pitch information processing means for performing pitch detection from the tone signal obtained by the pickup and outputting pitch detection success / failure information indicating success or failure of the pitch detection;
A distortion signal generating means for inputting the musical sound signal obtained by the pickup and generating a distortion signal based thereon;
An oscillator that generates an oscillation signal corresponding to the pitch detected by the pitch information processing means;
When the pitch detection success / failure information is information that positively detects the pitch, the oscillation signal generated by the oscillator is output, while the pitch detection success / failure information is information that rejects the pitch detection. Comprises an output control means for outputting a distortion signal generated by the distortion signal generation means. In the musical sound signal processing device according to claim 1,
The pitch detection success / failure information is 1-bit information. In the musical sound signal processing device according to claim 2,
The output control means includes
When the 1-bit pitch detection success / failure information is information that rejects pitch detection, a first multiplier that sets the coefficient to zero, a NOT circuit that inverts the pitch detection success / failure information, and the NOT circuit When the output is information indicating that the pitch success / failure information is negative, the second multiplier whose coefficient is zero, and the output of the first multiplier and the output of the second multiplier are added. A musical tone generator comprising: an adder; An apparatus for processing a musical tone signal of an electronic guitar equipped with a pickup for capturing a string vibration signal by string operation,
The musical tone signal obtained by the pickup is configured to be divided and input into a first input signal and a second input signal,
An adder that outputs an addition signal obtained by adding the first input signal and the second input signal;
Pitch information processing means for performing pitch detection from the addition signal and outputting pitch detection success / failure information indicating success or failure of pitch detection;
A distortion signal generation unit that inputs the addition signal and generates a distortion signal based on the input signal; an oscillator that generates an oscillation signal corresponding to the pitch detected by the pitch information processing unit;
An output control means for outputting an oscillation signal generated by the oscillator, or for outputting a distortion signal generated by the distortion signal generation means;
First amplitude determining means for outputting first information when the first input signal exceeds a first threshold;
Second amplitude determining means for outputting second information when the second input signal exceeds a second threshold;
Amplitude information output means for outputting third information when the first information and the second information are both predetermined values;
In the case where the pitch detection success / failure information is information that denies the detection of the pitch, or when the amplitude information output means outputs the third information, or in both cases, the distortion signal generation means A musical sound signal processing apparatus characterized in that the generated distortion signal is output. In the musical sound signal processing apparatus according to claim 4,
The first amplitude determining means includes
A first envelope detector that detects and outputs an envelope of the first input signal; and outputs the first information when an output result of the first envelope detector exceeds the first threshold. A first signal processing unit that includes:
The second amplitude determining means includes
A second envelope detector for detecting and outputting an envelope of the second input signal; and outputting the second information when an output result of the second envelope detector exceeds the second threshold value. A second signal processing unit that includes:
The amplitude information output means includes
A logical product circuit that takes a logical product with the output of the first signal processing unit and the output of the second signal processing unit as inputs.
Both the first information and the second information have the same logic and are different logics from the third information, and these are 1-bit information. A program for operating a musical tone signal processing apparatus equipped with an oscillator that processes a musical tone signal of an electronic guitar equipped with a pickup that captures a string vibration signal by string manipulation and generates an oscillation signal according to a detected pitch. ,
A pitch information processing function for performing pitch detection from a musical sound signal obtained by the pickup and outputting pitch detection success / failure information indicating success or failure of pitch detection;
A distortion signal generation function for inputting the musical sound signal obtained by the pickup and generating a distortion signal based thereon;
When the pitch detection success / failure information is information that positively detects the pitch, the oscillation signal generated by the oscillator is output, while the pitch detection success / failure information is information that rejects the pitch detection. A program for realizing in a computer an output control function for outputting the distortion signal generated by the distortion signal generation function.

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