Musical sound signal conversion device, musical sound signal conversion method and program

Abstract

To provide a musical sound signal conversion device which enables seamless switching from pedal wah to auto wah and from auto wah to pedal wah.SOLUTION: A musical sound signal conversion device includes: a control unit for switching conversion of a musical sound signal from conversion corresponding to operation of pedal wah to conversion corresponding to auto wah or switching conversion from conversion corresponding to auto wah to conversion corresponding to operation of pedal wah; and a WAH circuit unit for performing conversion of the musical sound signal corresponding to operation of pedal wah or conversion of the musical sound signal corresponding to auto wah. The control unit includes an interpolation filter part for performing filter processing to interpolate so that a change of a resonance frequency of a wah filter continues with switching during switching from pedal wah to auto wah or switching from auto wah to pedal wah.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a musical sound signal conversion device, a musical sound signal conversion method, and a program for converting a musical sound signal. [Background technology]

[0002] Pedal wah is an effect that changes the tone by controlling the electronic circuitry, such as a variable resistor, located below the pedal depending on how hard you press it, and changing the resonance frequency of the filter circuit. The change in tone produced by pedal wah is called the wah effect.

[0003] An auto-wah is an effector that does not control the wah effect with a pedal, but rather produces a wah effect at a set frequency or amplitude, or changes the intensity of the wah effect in response to the strength of the input sound.

[0004] Pedal wah and auto wah are disclosed in, for example, Non-Patent Document 1. [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] Shimamura Musical Instruments Co., Ltd., “[Too Old to Ask] Basic Knowledge of Effector ~Filter Effects~”, [online], Shimamura Musical Instruments Co., Ltd., [Retrieved March 6, 2024], Internet〈URL:https: / / guitarsele.com / article / feature / basic-knowledge-of-effector-filter / 2 / 〉 Summary of the Invention [Problem to be solved by the invention]

[0006] When using pedal wah, the user must operate the pedal while playing the instrument, which provides a degree of freedom but also requires high playability, and because the user has to operate the pedal, quick and precise control is difficult.

[0007] When using auto-wah, it is possible to create a quick, rhythmic wah effect that is not possible with pedal operation, but the effect is limited to a preset parameter value and input sound, making it difficult to change the intensity of the effect in the middle of a performance.

[0008] By providing both pedal wah and auto-wah and allowing the user to switch between them, both effects can be achieved. In this case, the user must control the ON / OFF of each, which creates a time lag. Another problem is that the change in tone becomes intermittent when switching between them.

[0009] Therefore, an object of the present disclosure is to provide a musical sound signal conversion device that can seamlessly switch from pedal wah to auto-wah and from auto-wah to pedal wah. [Means for solving the problem]

[0010] The musical sound signal conversion device of the present disclosure includes a control unit and a WAH circuit unit, and the control unit includes an interpolation filter unit.

[0011] The control unit switches the conversion of the musical tone signal from conversion according to pedal wah operation to conversion according to auto-wah, or from conversion according to auto-wah to conversion according to pedal wah operation.

[0012] The WAH circuit section converts a musical tone signal in response to a pedal wah operation or in response to an auto-wah operation.

[0013] The interpolation filter section performs filtering processing to interpolate so that the change in the resonance frequency of the wah filter accompanying the switching is continuous when switching from pedal wah to auto-wah or when switching from auto-wah to pedal wah. [Effects of the Invention]

[0014] According to the musical sound signal conversion device of the present disclosure, seamless switching from pedal wah to auto-wah and from auto-wah to pedal wah is possible. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a block diagram showing the functional configuration of a musical sound signal conversion device according to a first embodiment. [Figure 2] 3 is a flowchart showing the operation of the musical sound signal conversion device of the first embodiment. [Figure 3] 4 is a flowchart showing the operation of a control unit of the musical sound signal conversion device according to the first embodiment. [Figure 4] 10 is a flowchart showing the operation of the envelope generator / follower section. [Figure 5] 10A and 10B are diagrams showing examples of transition times and transition times with smoothing. [Figure 6] FIG. 2 is a diagram showing an example of the functional configuration of a computer. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, embodiments of the present disclosure will be described in detail. Note that components having the same functions are assigned the same numbers, and redundant explanations will be omitted. [Example]

[0017] The functional configuration of the musical sound signal conversion device of the first embodiment will be described below with reference to Fig. 1. As shown in Fig. 1, the musical sound signal conversion device 1 of the present embodiment includes an AD conversion unit 11, an AD conversion unit 12, a control unit 13, a digital potentiometer 14, a WAH circuit unit 15, an operator 16, an operator 17, and an operator 18. The control unit 13 includes an envelope generator / follower unit 131, an operation detection unit 132, a transition time management unit 133, an interpolation filter unit 134, and a switching unit 135. The musical sound signal conversion device 1 is connected so as to be able to acquire signals from a pedal 51 of a pedal wah and a musical instrument 52. The pedal 51 of the pedal wah may include a sensor 51a that detects contact with the pedal wah.

[0018] The musical instrument 52 is typically an electric musical instrument such as an electric guitar or an electronic piano, but may also be an acoustic musical instrument, a wind instrument, etc. that is played without electrical amplification. When the musical instrument 52 is an acoustic musical instrument, a wind instrument, etc., a microphone for acquiring the musical sound signal of the musical instrument is separately required.

[0019] Hereinafter, the operations of each component will be described with reference to FIG. 2.

[0020] <AD conversion unit 11> The AD conversion unit 11 acquires the value of a variable resistor (VR) interlocked with the pedal 51 and performs AD conversion on the variable resistance value (S11).

[0021] <AD conversion unit 12> The AD conversion unit 12 acquires an input signal from the musical instrument 52 (or a microphone) and performs AD conversion on the input signal (S12).

[0022] <Control unit 13> The control unit 13 switches the conversion of the musical sound signal from the conversion according to the operation of the pedal wah to the conversion according to the auto wah, or switches from the conversion according to the auto wah to the conversion according to the operation of the pedal wah (S13). The control unit 13 can be realized by, for example, a CPU (a Central Processing Unit).

[0023] <Digital potentiometer 14> The digital potentiometer 14 is controlled by the control unit 13 based on the AD value of the variable resistor (VR) interlocked with the pedal 51 during the pedal wah operation and outputs an analog value. Also, during the auto wah operation, it is controlled by the control unit 13 based on the envelope generated / extracted from the AD value of the input signal from the musical instrument 52 and outputs a corresponding value (analog value or digital value).

[0024] <WAH circuit unit 15> The WAH circuit section 15 converts the musical sound signal in accordance with the pedal wah operation or the auto-wah, based on the analog value obtained from the digital potentiometer 14 (S15).

[0025] <Controller 16> Operator 16 is an operator for setting the length of transition time (the time required to switch from pedal wah to auto wah, or from auto wah to pedal wah), which will be described later.

[0026] <Controller 17> Operator 17 is an operator for adjusting the magnitude of the attack during auto-wah operation.

[0027] <Controller 18> Operator 18 is an operator for adjusting the magnitude of Decay / Sens during auto-wah operation.

[0028] <Other> Although not shown in the figure, the musical tone signal conversion device 1 has the following functions in addition to the operators 16-18. Input jack Output jack 3-mode toggle switch Polarity switch The three-mode toggle switch is a switch that switches the musical sound signal converting device 1 between the manual mode, the envelope generator mode, and the envelope follower mode.

[0029] The polarity switch is a switch that switches the polarity of the auto-wah.

[0030] [Manual mode] The manual mode is a mode in which the wah effect is obtained in response to the operation of the pedal 51, and the pedal operates as a so-called normal pedal wah.

[0031] The following two modes operate as pedal wah when operation of the pedal 51 is detected, and are modes that provide an auto-wah effect based on the input musical tone when operation of the pedal 51 is not detected.

[0032] [Envelope Generator Mode] The envelope generator mode is a mode in which, during auto-wah operation, the attack of the input sound (picking, keystroke, etc.) is detected and the wah effect is applied according to the set parameter value. In this specification, the envelope generator mode is referred to as generating an envelope.

[0033] In Envelope Generator mode, an envelope generator that changes between Min and Max with each attack, regardless of playing strength, creates an active auto-wah effect. Also, by setting the Attack and Release to a value similar to that produced when using a pedal wah rhythmically, you can achieve a natural auto-wah effect.

[0034] In envelope generator mode, a pulse is generated each time an attack is detected, and the generated pulse is used as a trigger to operate the envelope generator, thereby controlling the wah resonance frequency.

[0035] [Envelope follower mode] The envelope follower mode is a mode in which the intensity of the wah effect changes in response to the envelope of the input sound during auto-wah operation. In this specification, the envelope follower mode is referred to as extracting or detecting the envelope.

[0036] In a conventional auto-wah, the resonant frequency of the wah filter is changed by the input level of the instrument 52, so as long as there is input, the resonant frequency rises and cannot reach a minimum value.

[0037] Therefore, in the envelope follower mode of this embodiment, when the input is smaller than a certain level, the resonance frequency is set to the minimum value. As a result, even if there is input from the instrument 52, if the performance is weak, the resonance frequency will be set to the minimum value, and the resonance frequency will move between min and max. This allows the effect of moving back and forth across a wide variable range, like when operating a pedal wah, to be obtained according to the playing strength.

[0038] The operation of each component in the control unit 13 will be described below with reference to FIGS.

[0039] <Envelope Generator / Follower Section 131> As shown in FIG. 3, the envelope generator / follower section 131 turns off its function or generates / extracts an envelope depending on the mode (S131).

[0040] 4 shows in detail the operation of the envelope generator / follower section 131. As shown in the figure, the envelope generator / follower section 131 does not operate when the musical sound signal converting device 1 is in the manual mode.

[0041] When the musical sound signal conversion device 1 is in envelope generator mode, the envelope generator / follower unit 131 generates a pulse each time an attack is detected from the input signal of the musical instrument 52 (or microphone), and generates an envelope that changes between min and max using the generated pulse as a trigger (S131G).

[0042] Furthermore, when the musical sound signal converting device 1 is in the envelope follower mode, the envelope generator / follower section 131 extracts an envelope from the input signal of the musical instrument 52 (or microphone) (S131F).

[0043] <Operation detection unit 132> The operation detection unit 132 detects a pedal wah operation, and when the pedal wah operation changes state from detected to undetected, determines that a switch has occurred from pedal wah to auto wah, and when the pedal wah operation changes state from undetected to detected, determines that a switch has occurred from auto wah to pedal wah (S132).

[0044] [Operation detection] The method for detecting pedal wah operation differs depending on the type of pedal wah. For example, there are the following AC types of pedal wah:

[0045] Type A: This type is considered to be operating pedal wah only when the user is pressing down pedal 51. In Type A, even if the user keeps part of their body, such as a foot or hand, in contact with pedal 51, it is not considered to be operating pedal wah unless they are pressing down pedal 51.

[0046] Type B: This type considers the pedal wah operation to be in progress when the user is in contact with the pedal 51. Unlike Type A, if the user is in contact with the pedal 51 with a part of their body, such as a foot or hand, it is considered that the pedal wah is being operated, even if the pedal is not being pressed.

[0047] Type C: The pedal 51 is designed to return to its initial position when the user is not touching it, and is considered to be in pedal wah operation only when the pedal 51 is not in its initial position. In the case of Type C, the pedal 51 is provided with a spring or the like for returning it to its initial position.

[0048] In the case of the implementation example of Type A, the operation detection unit 132 determines that a pedal wah operation has been detected when a change in the resistance value of the variable resistor (VR) linked to the pedal 51 occurs (S132A).

[0049] In the implementation example of Type B, the operation detection unit 132 determines that a pedal wah operation has been detected when the detection value of the sensor 51a (contact detection) provided in the pedal wah exceeds a predetermined threshold (S132B).

[0050] In the case of an implementation example of Type C, the operation detection unit 132 determines that a pedal wah operation has been detected when the variable resistor (VR) linked to the pedal 51 indicates a resistance value other than the resistance value of the initial position (S132C).

[0051] <<Transition Time Management Section 133>> The transition time management section 133 determines whether a predetermined transition time has elapsed when switching from pedal wah to auto-wah, or when switching from auto-wah to pedal wah (S133). As mentioned above, the length of the transition time can be changed by the user by operating the controls 16. The transition time is set to prevent the following chattering phenomenon.

[0052] [Chattering phenomenon] If switching were to be performed the instant the pedal operation state changed (from detected to undetected, or from undetected to detected), switching would occur too frequently, resulting in chattering. Therefore, a certain transition time is set, and switching is performed only after the transition time has elapsed, thereby avoiding chattering.

[0053] The transition time management section 133 may determine whether the transition time has elapsed or not for both switching from pedal wah to auto wah and switching from auto wah to pedal wah (this is called a two-sided determination).

[0054] Furthermore, the transition time management section 133 may determine whether the transition time has elapsed or not only for switching from pedal wah to auto wah (this is called one-sided P→A determination).

[0055] Furthermore, the transition time management section 133 may determine whether the transition time has elapsed or not only for switching from auto-wah to pedal wah (this is called one-side A→P determination).

[0056] The features of each determination method will be described below with reference to FIG.

[0057] [Two-sided judgment] In the two-sided determination, the effect switches to auto-wah after the transition time has elapsed after the user stops operating the pedal 51. Also, the effect switches to pedal-wah after the transition time has elapsed after the user resumes operating the pedal 51.

[0058] Furthermore, if the transition time can be varied between, for example, 100 and 1000 ms, the switching response can be adjusted to suit the user's preferences and performance expression, while also avoiding chattering. For example, a short setting of around 100 ms provides a very fast switching response, avoiding chattering while allowing for finely tuned performance expression by switching back and forth between the two modes. On the other hand, if the transition time is set to a longer value, such as 500 ms, it can prevent unintentional switching to auto-wah mode when the pedal is stopped for a certain period of time, even though the user intends to move the pedal gently.

[0059] As shown in the figure, after the transition time has elapsed, a transition period occurs that involves interpolation by filtering.

[0060] [One-sided P → A judgment] In the one-sided P→A judgment, the effect switches to auto-wah after the transition time has elapsed after the user stops operating the pedal 51. The effect also switches to pedal wah the moment the user resumes operating the pedal 51.

[0061] This determination method achieves instantaneous response for A → P switching, further improving user operability, and by providing a transition time only for P → A switching, it is possible to prevent frequent switching and avoid chattering.

[0062] [One-sided A→P judgment] In the one-sided A→P judgment, the effect switches to auto-wah the moment the user stops operating the pedal 51. Also, after the user resumes operating the pedal 51, the effect switches to pedal wah after the transition time has elapsed.

[0063] This determination method achieves instantaneous response for P → A switching, further improving user operability, and by providing a transition time only for A → P switching, it is possible to prevent frequent switching and avoid chattering.

[0064] In addition, when setting the two-sided judgment, even if the transition time on one side is set to 0 [ms], the same effect as the above [one-sided P → A judgment] and [one-sided A → P judgment] can be obtained.

[0065] <<Interpolation filter unit 134>> The interpolation filter section 134 performs filtering processing to interpolate the change in the resonance frequency of the wah filter that accompanies the switching so that it is continuous when switching from pedal wah to auto-wah or when switching from auto-wah to pedal wah (S134).

[0066] The interpolation filter section 134 is provided to prevent the resonance frequency of the wow filter from shifting discontinuously at the moment of switching, thereby generating noise.

[0067] <<Switching unit 135>> The switching unit 135 performs switching when the operation detection unit 132 detects a state change and there is no determination as to whether the transition time has elapsed or not, or when the operation detection unit 132 detects a state change and the transition time management unit 133 determines that the transition time has elapsed (S135).

[0068] <Effects> According to the musical sound signal conversion device of the present disclosure, the position of the pedal 51 and the input sound from the musical instrument 52 are detected by the control unit 13 (e.g., a CPU), and the filter circuit is controlled based on these to produce a wah effect. While the pedal 51 is moving, the pedal wah operation takes priority, and when the pedal operation is stopped, the auto-wah effect is obtained, and the tone change during switching can be made smooth by setting the switching time (transition time) and by performing an interpolation process to ensure that the change in the resonance frequency of the filter during switching is continuous.

[0069] According to the musical sound signal conversion device disclosed herein, it is possible to seamlessly switch between pedal wah operation and auto-wah operation, thereby enabling performance expressions that were previously impossible, such as partially assisting pedal wah operation, which requires skill, with auto-wah, or quickly switching between pedal wah and auto-wah effects.

[0070] Furthermore, while many common auto-wah effects control filters such as state variable or bandpass filters, the musical sound signal conversion device of the present disclosure is capable of controlling the same filter circuit as a conventional pedal wah.

[0071] <Additional Notes> The functions performed by the components described herein may be implemented in circuitry or processing circuitry, including general-purpose processors, application-specific processors, integrated circuits, ASICs (Application Specific Integrated Circuits), a CPU (a Central Processing Unit), conventional circuits, and / or combinations thereof, programmed to perform the described functions. A processor includes transistors and other circuits and is considered to be circuitry or processing circuitry. A processor may also be a programmed processor that executes programs stored in memory.

[0072] In this specification, a circuitry, unit, or means is hardware that is programmed to realize or performs the described functions, which may be any hardware disclosed herein or any hardware known to be programmed to realize or perform the described functions.

[0073] If the hardware is a processor considered to be a type of circuitry, the circuitry, means, or unit is a combination of the hardware and software used to configure the hardware and / or processor.

[0074] The various processes described above can be implemented by loading a program that executes each step of the above method into the recording unit 10020 of the computer shown in Figure 6 and operating the control unit 10010, input unit 10030, output unit 10040, etc.

[0075] The program describing the processing contents can be recorded on a computer-readable recording medium, which may be, for example, a magnetic recording device, an optical disk, a magneto-optical recording medium, a semiconductor memory, or any other suitable recording medium.

[0076] The program may be distributed, for example, by selling, transferring, lending, etc. a portable recording medium such as a DVD or CD-ROM on which the program is recorded. Furthermore, the program may be stored in a storage device of a server computer, and then transferred from the server computer to another computer via a network, thereby distributing the program.

[0077] A computer that executes such a program may first temporarily store the program recorded on a portable recording medium or transferred from a server computer in its own storage device. Then, when executing a process, the computer reads the program stored on its own recording medium and executes the process in accordance with the read program. Alternatively, the computer may read the program directly from a portable recording medium and execute the process in accordance with the program. Furthermore, the computer may execute the process in accordance with the program each time a program is transferred from a server computer to the computer. The server computer may not transfer the program to the computer, but may instead execute the process through a so-called ASP (Application Service Provider) service, which realizes the processing function by issuing an execution instruction and obtaining the results. Furthermore, the server computer may execute the process on a terminal using a so-called SaaS (Software as a Service) service, which allows users to use part of the server computer along with the program. In this embodiment, the program includes information used for computer processing that is equivalent to a program (such as data that is not a direct instruction to the computer but has properties that define computer processing).

[0078] Furthermore, in this embodiment, the device is configured by executing a predetermined program on a computer, but at least a part of the processing contents may be realized by hardware.

Claims

1. a control unit that switches the conversion of musical tone signals from conversion corresponding to pedal wah operation to conversion corresponding to auto-wah operation, or from the conversion corresponding to auto-wah operation to conversion corresponding to pedal wah operation; a WAH circuit section that converts a musical tone signal in response to the pedal wah operation or converts the musical tone signal in response to the auto-wah operation, The control unit and an interpolation filter section that executes a filter process to interpolate so that the change in the resonance frequency of the wah filter accompanying the switching is continuous when switching from the pedal wah to the auto wah or when switching from the auto wah to the pedal wah. Musical sound signal converter.

2. 2. The musical sound signal conversion device according to claim 1, The control unit an operation detection unit that detects the pedal wah operation, and determines that the pedal wah has been switched to the auto-wah when the pedal wah operation has changed from a detected state to a non-detected state, and determines that the auto-wah has been switched to the pedal wah when the pedal wah operation has changed from a non-detected state to a detected state; Musical sound signal converter.

3. 3. The musical sound signal conversion device according to claim 2, The operation detection unit When a change in resistance value of a variable resistor linked to the pedal of the pedal wah occurs, it is determined that the operation of the pedal wah has been detected. Musical sound signal converter.

4. 3. The musical sound signal conversion device according to claim 2, The operation detection unit When a detection value of a contact sensor provided on the pedal wah exceeds a predetermined threshold, it is determined that the pedal wah operation has been detected. Musical sound signal converter.

5. 3. The musical sound signal conversion device according to claim 2, The pedal of the pedal wah returns to its initial position when not touched by the user, The operation detection unit When a variable resistor linked to the pedal of the pedal wah indicates a resistance value other than the resistance value at the initial position, it is determined that the operation of the pedal wah has been detected. Musical sound signal converter.

6. 6. The musical tone signal conversion device according to claim 2, The control unit a transition time management section that determines whether a predetermined transition time has elapsed or not for switching from the pedal wah to the auto wah or for switching from the auto wah to the pedal wah; a switching unit that executes the switching when the transition time has elapsed Musical sound signal converter.

7. 7. The musical sound signal conversion device according to claim 6, The transition time management unit It is determined whether the transition time has elapsed or not only for the switching from the pedal wah to the auto wah. Musical sound signal converter.

8. 7. The musical sound signal conversion device according to claim 6, The transition time management unit It is determined whether the transition time has elapsed or not only for the switching from the auto-wah to the pedal-wah. Musical sound signal converter.

9. A musical sound signal conversion method executed by a musical sound signal conversion device, comprising: a control step of switching the conversion of the musical tone signal from conversion corresponding to a pedal wah operation to conversion corresponding to an auto-wah operation, or switching the conversion corresponding to the auto-wah operation to conversion corresponding to the pedal wah operation; a WAH circuit step for converting a musical tone signal in response to the pedal wah operation or in response to the auto-wah operation, The control step and an interpolation filter step for executing a filter process for interpolating a change in the resonance frequency of a wah filter that occurs when switching from the pedal wah to the auto-wah or when switching from the auto-wah to the pedal wah so that the change in the resonance frequency of the wah filter that occurs when switching is continuous. A method for converting musical sound signals.

10. A program that causes a computer to function as the musical tone signal conversion device according to claim 1.

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