Signal filtering method, device, equipment, medium and program product

Abstract

The invention relates to a signal filtering method, device and equipment, a medium and a program product in the technical field of signal processing, and the method comprises the steps: determining a target transfer function of each parameter equalizer in a graphic equalizer according to a sampling rate, each center frequency and an analog amplitude at each center frequency; determining a target gain of each parameter equalizer according to the target transfer function and the expected amplitude response at each center frequency; determining a target filter coefficient of each parameter equalizer according to the target transfer function, the center frequency, the sampling rate, the preset bandwidth and the target gain of each parameter equalizer; taking the target filter coefficient corresponding to each parameter equalizer as a target, and adjusting the function expression of each parameter equalizer to obtain a target graphic equalizer; and inputting the obtained signal to be filtered into the target graphic equalizer to obtain a target signal output after filtering of the target graphic equalizer. And the accuracy and convenience of signal filtering are improved.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of signal processing, and particularly relates to a signal filtering method and device, equipment, medium and program product. BACKGROUND

[0002] Filter coefficients of a parametric equalizer (PEQ) in a graphic equalizer (GEQ) are directly calculated to obtain a set of fixed center frequencies and quality factors under different gains according to a series of gain values input by a user, and then filter coefficients of the parametric equalizer under different gains are obtained, which causes a serious deviation between a final real gain value at each center frequency and a target gain. SUMMARY

[0003] To overcome the problems in the related art, the present disclosure provides a signal filtering method, device, equipment, medium and program product.

[0004] According to a first aspect of an embodiment of the present disclosure, a signal filtering method is provided, comprising: determining a target transfer function of each parametric equalizer in a graphic equalizer according to a sampling rate, each center frequency and an analog amplitude at each center frequency; determining a target gain of each parametric equalizer according to the target transfer function and an expected amplitude response at each center frequency; determining a target filter coefficient of each parametric equalizer according to the target transfer function, the center frequency, the sampling rate, a preset bandwidth and the target gain corresponding to each parametric equalizer; adjusting a function expression of each parametric equalizer with the target filter coefficient corresponding to each parametric equalizer as a target to obtain a target graphic equalizer; inputting a to-be-filtered signal obtained to the target graphic equalizer to obtain a target signal output by the target graphic equalizer after filtering.

[0005] According to a second aspect of an embodiment of the present disclosure, a signal filtering device is provided, comprising: a first determining module configured to determine a target transfer function of each parametric equalizer in a graphic equalizer according to a sampling rate, each center frequency and an analog amplitude at each center frequency; a second determining module configured to determine a target gain of each parametric equalizer according to the target transfer function and an expected amplitude response at each center frequency; The third determining module is configured to determine target filter coefficients of each parameter equalizer according to the target transfer function, the center frequency, the sampling rate, a preset bandwidth, and the target gain corresponding to each parameter equalizer. The adjusting module is configured to adjust a function expression of each parameter equalizer to obtain a target graphic equalizer, with the target filter coefficient corresponding to each parameter equalizer as a target. The filtering module is configured to input the obtained to-be-filtered signal into the target graphic equalizer to obtain a target signal output by the target graphic equalizer after filtering.

[0006] According to a third aspect of the embodiments of the present disclosure, an electronic device is provided, including: a processor; a memory for storing processor-executable instructions; The processor is configured to execute the executable instructions stored in the memory to implement the method in any of the first aspect.

[0007] According to a fourth aspect of the embodiments of the present disclosure, a computer-readable storage medium is provided, which stores a computer program. When the computer program is executed by a processor, the steps of the method in any of the first aspect are implemented.

[0008] According to a fifth aspect of the embodiments of the present disclosure, a computer program product is provided, including a computer program. When the computer program is executed by a processor, the steps of the method in any of the first aspect are implemented.

[0009] The technical solutions provided by the embodiments of the present disclosure can include the following beneficial effects: According to the sampling rate, each center frequency, and the analog amplitude at each center frequency, the target transfer function of each parameter equalizer in the graphic equalizer is determined. According to the target transfer function and the expected amplitude response at each center frequency, the target gain of each parameter equalizer is determined. According to the target transfer function, the center frequency, the sampling rate, the preset bandwidth, and the target gain of each parameter equalizer, the target filter coefficient of each parameter equalizer is determined. With the target filter coefficient corresponding to each parameter equalizer as a target, the function expression of each parameter equalizer is adjusted to obtain a target graphic equalizer. The to-be-filtered signal obtained is input into the target graphic equalizer to obtain a target signal output by the target graphic equalizer after filtering. The accuracy of the coefficient adjustment of each parameter equalizer in the graphic equalizer is improved, thereby improving the accuracy of signal filtering. Moreover, when the graphic equalizer is filtered, manual correction of the filter coefficient is avoided, and the convenience is improved.

[0010] It should be understood that the foregoing general description and the following detailed description are only exemplary and explanatory, and cannot limit the present disclosure. Attached Figure Description

[0011] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure.

[0012] Figure 1 This is a schematic diagram showing the amplitude-frequency response at different frequencies.

[0013] Figure 2 This is a schematic diagram showing the amplitude-frequency response of a parametric equalizer cascaded for different center frequencies in a relevant scenario.

[0014] Figure 3 This is a flowchart illustrating a signal filtering method according to an exemplary embodiment.

[0015] Figure 4 This is a schematic diagram illustrating the setting of gain at different center frequencies according to an exemplary embodiment.

[0016] Figure 5 This is an implementation illustrated according to an exemplary embodiment. Figure 3 The flowchart for step S11.

[0017] Figure 6 This is an implementation illustrated according to an exemplary embodiment. Figure 3 The flowchart for step S13.

[0018] Figure 7 This is an implementation illustrated according to an exemplary embodiment. Figure 3 The flowchart for step S12.

[0019] Figure 8 This is a schematic diagram illustrating the amplitude-frequency response of a cascaded parametric equalizer for different center frequencies, according to an exemplary embodiment.

[0020] Figure 9 This is a block diagram illustrating a signal filtering device according to an exemplary embodiment.

[0021] Figure 10 This is a block diagram illustrating an apparatus for signal filtering according to an exemplary embodiment. Detailed Implementation

[0022] The exemplary embodiments will be described in detail herein with reference to the attached drawings. The following description is made in connection with the drawings, in which the same reference numerals represent the same elements throughout the several figures, and the components in the figures are not necessarily to scale. The following description of exemplary embodiments is not representative of all embodiments consistent with the present disclosure. Rather, they are merely examples of apparatus and methods consistent with some aspects of the present disclosure as detailed in the appended claims.

[0023] The following description of exemplary embodiments is not representative of all embodiments consistent with the present disclosure. Rather, they are merely examples of apparatus and methods consistent with some aspects of the present disclosure as detailed in the appended claims.

[0024] It should be noted that all the actions of acquiring signals, information or data in the present disclosure are carried out in compliance with the corresponding data protection regulations and policies of the country where the device is located, and with the authorization given by the owner of the corresponding device.

[0025] Before introducing the signal filtering method, device, equipment, medium and program product provided by the present disclosure, since the mutual influence between the parametric filters PEQ is not considered, the parametric filters PEQ are not narrowband filters, and different filters will interact at the same frequency, so as shown in Figure 1 , the amplitude-frequency response at each center frequency is set, and the final target signal is shown in Figure 2 , Figure 2 The filter response represented by the middle curve has a serious deviation from the expected response at each center frequency represented by the circle. It can be seen that the filter response of the graphic equalizer deviates seriously from the expected response, and thus needs to be adjusted again to make the filter response of the graphic equalizer approach the expected response.

[0026] In the related scenario, in order to overcome the serious deviation between the final real gain value at each center frequency and the target gain, the transfer function of the filter is modified by a bilinear transformation constant, and then the filter coefficients are determined according to the modified transfer function. However, in this way, for audio with different sampling rates, the non-linear transformation will cause the response at the Nyquist frequency to be 0, thereby causing the several parametric filters with relatively high center frequencies to have an asymmetric amplitude response. Therefore, not only the parametric filters whose bandwidths need to be adjusted at the sampling rate need to be determined, but also how much the bandwidths of the adjusted parametric filters need to be adjusted, resulting in low convenience of audio processing. For example, when the sampling rate is 44.1 kHz, the bandwidths of some parametric filters are determined to be adjusted to , and the bandwidths of the last three filters cannot be , but are respectively:

[0027] In view of this, the present disclosure provides a signal filtering method that aims to solve the serious deviation between the final true gain value and the target gain at each center frequency, while improving the ease of use of the graphic equalizer.

[0028] Figure 3 This is a flowchart illustrating a signal filtering method according to an exemplary embodiment, such as... Figure 1 As shown, it includes the following steps.

[0029] In step S11, the target transfer function of each parameter equalizer in the graphic equalizer is determined based on the sampling rate, each center frequency, and the analog amplitude at each center frequency. The graphic equalizer (GEQ) provided in this disclosure is a filter that can control the frequency response gain of different frequency bands. It can be used for audio signal processing in audio, music, and video, for example. The graphic equalizer can be constructed by cascading or paralleling two second-order infinite impulse response (IIR) filters. It can be applied to applications such as music production, radio stations, live sound control, and personal media playback devices.

[0030] For example, in the case of live sound control, the sound engineer first needs to measure the amplitude response of the speaker system. Then, based on the measured amplitude-frequency response and the desired amplitude-frequency response, they calculate the gain value that needs to be adjusted for each frequency. Finally, they use a graphic equalizer with adjusted filter coefficients to adjust the speaker system. Similar procedures apply to listening environments such as home theaters, cinemas, concerts, or cars, and will not be elaborated upon here.

[0031] Here, sampling rate refers to the number of times the signal to be processed is sampled per second, expressed in Hertz (Hz). Center frequency refers to the frequency at which the equalizer's response is strongest for each parameter in the graphic equalizer. Analog amplitude is the magnitude or intensity of the signal at the center frequency. Transfer function is a mathematical function used to describe the relationship between input and output.

[0032] In this embodiment of the disclosure, during audio processing, a graphic equalizer is used to adjust the gain of different frequency components, thereby altering the spectral characteristics of the audio signal. For example, the target transfer function of each parametric equalizer (typically a bandpass filter) in the graphic equalizer is determined based on the audio signal's sampling rate (e.g., 44.1 kHz), various preset center frequencies (e.g., 60 Hz, 250 Hz, 1 kHz, etc.), and the analog amplitude values ​​at these center frequencies. The transfer function is a mathematical expression that describes the relationship between the input signal and the output signal after filter processing.

[0033] For example, suppose a five-band graphic equalizer has a sampling rate of 44.1kHz and center frequencies of 60Hz, 250Hz, 1kHz, 4kHz, and 16kHz. At each center frequency, an analog amplitude value is measured or preset. This analog amplitude value can be measured using an analog filter. Based on these values, a bandpass filter can be designed for each center frequency, whose transfer function ensures a gain peak near that center frequency, and that the gain value matches the preset analog amplitude.

[0034] In step S12, the target gain of each of the parametric equalizers is determined based on the target transfer function and the expected amplitude response at each of the center frequencies. Here, the target gain is the amount of amplification or attenuation that the parametric equalizer needs to achieve at a specific frequency. The desired amplitude response is the amplitude response characteristic that the filter is expected to achieve when used as a parametric equalizer in a graphic equalizer.

[0035] In this embodiment of the disclosure, after determining the target transfer function, the target gain that each parametric equalizer needs to achieve is calculated based on this transfer function and the desired amplitude response at each center frequency. This gain value determines the degree to which the filter amplifies or attenuates the signal passing through it at a specific frequency.

[0036] For example, continuing the previous example, if the desired amplitude response increase at the 1kHz center frequency is 2dB, then the target gain of the parametric equalizer at 1kHz is 2dB. See also... Figure 4 As shown, for the center frequencies of octaves or 1 / 3 octaves, which are 31.25, 62.5, 125, 250, 500, 1000, 2000, 4000, 80000, and 16000 Hz respectively, a filter is set for each frequency band, i.e., a 10-band graphic equalizer (GEQ). If the desired amplitude response at the center frequency of 200 Hz is a boost of -12 dB, then the target gain of the parametric equalizer at 200 Hz is -12 dB.

[0037] In step S13, the target filtering coefficients of each parameter equalizer are determined based on the target transfer function, the center frequency, the sampling rate, the preset bandwidth, and the target gain corresponding to each parameter equalizer. The filter coefficients are a set of parameters used to adjust the filter's performance and determine its frequency response characteristics. The preset bandwidth is the frequency range that the filter is allowed to pass through.

[0038] In this embodiment of the disclosure, the filter coefficients of each parametric equalizer are calculated based on the target transfer function, center frequency, sampling rate, and preset bandwidth. These coefficients directly determine the filter's performance, including gain, bandwidth, and cutoff frequency.

[0039] For example, suppose a parametric equalizer with a center frequency of 1kHz has a known target gain of 2dB, a sampling rate of 44.1kHz, and a preset bandwidth of 1 / 3 octave. In this case, digital signal processing algorithms (such as the BiQuad filter design algorithm) can be used to calculate the filter coefficients to ensure a gain of 2dB at 1kHz and a flat response within the preset bandwidth.

[0040] In step S14, the function expression of each parameter equalizer is adjusted with the target filter coefficient corresponding to each parameter equalizer as the target to obtain the target graphic equalizer.

[0041] In this embodiment, after determining the filter coefficients of each parametric equalizer, the function expression of each parametric equalizer is adjusted to ensure it conforms to the calculated filter coefficients. This allows the entire graphic equalizer to achieve the expected performance specifications. Each parametric equalizer is precisely tuned to ensure it has the expected gain and bandwidth at its respective center frequency. Ultimately, a five-band graphic equalizer is obtained, capable of providing precise gain adjustment at center frequencies of 60Hz, 250Hz, 1kHz, 4kHz, and 16kHz, thereby meeting the needs of audio processing.

[0042] In step S15, the acquired signal to be filtered is input into the target graphic equalizer to obtain the target signal output by the target graphic equalizer after filtering.

[0043] In this embodiment of the disclosure, the signal to be filtered can be an audio signal, such as 44.1kHz audio, 48kHz high-fidelity audio, etc.

[0044] The signal to be filtered is the original signal that needs to be filtered, which may contain noise, interference, or other unwanted frequency components. It may come from various sensors, audio devices, communication devices, or other data sources. The signal to be filtered usually contains useful information, but may also contain noise, interference signals, or other unwanted frequency components. The purpose of filtering is to remove these unwanted components and highlight or retain the useful signal components.

[0045] For example, in the field of audio processing, a live music performance signal recorded by a microphone may contain interference such as audience noise and equipment noise, which need to be removed or reduced through filtering.

[0046] In this process, the signal to be filtered is fed into a graphic equalizer for processing. The graphic equalizer sets the filtering coefficients according to the preceding steps, enhancing or attenuating signals in different frequency bands. This processing can highlight certain frequency components while suppressing other unwanted frequency components, thus achieving the filtering effect. The processed signal is the target signal.

[0047] The above technical solution determines the target transfer function of each parameter equalizer in the graphic equalizer based on the sampling rate, center frequencies, and analog amplitudes at each center frequency; determines the target gain of each parameter equalizer based on the target transfer function and the desired amplitude response at each center frequency; determines the target filter coefficients of each parameter equalizer based on the target transfer function, center frequency, sampling rate, preset bandwidth, and target gain of each parameter equalizer; and adjusts the function expression of each parameter equalizer using the target filter coefficient as the target to obtain the target graphic equalizer. The acquired signal to be filtered is input into the target graphic equalizer to obtain the target signal output after filtering. When the sampling rate, center frequency, and number of segments change, no additional manual parameter correction is required; the filter coefficients can be directly adjusted using the target filter coefficients, improving the accuracy of coefficient adjustment for each parameter equalizer in the graphic equalizer, thereby improving the accuracy of signal filtering. Furthermore, manual correction of filter coefficients is avoided during the filtering process of the graphic equalizer. This not only solves the serious deviation between the final true gain value and the target gain at each center frequency but also improves the ease of use of the graphic equalizer.

[0048] Optionally, see Figure 5 As shown, in step S11, determining the target transfer function of each parameter equalizer in the graphic equalizer based on the sampling rate, each center frequency, and the analog amplitude at each center frequency includes: In step S111, the transformation constant is determined based on the center frequency and the sampling rate; The transformation constant is a constant used to convert analog frequencies into digital frequencies during digital signal processing, and it is usually related to the sampling rate.

[0049] In step S112, the digital frequency corresponding to each center frequency is determined based on the transformation constant, the center frequency, and the sampling rate. In this embodiment of the disclosure, during signal processing, since the signal is sampled from the continuous-time domain to the discrete-time domain, it is necessary to convert the analog frequency (in Hertz) to the digital frequency (in radians per sample). This conversion is typically achieved through a transformation constant that is related to the sampling rate. The transformation constant can improve the accuracy of mapping the frequency characteristics of the analog domain to the digital domain.

[0050] For example, suppose there is an analog signal with a sampling rate of 48000Hz and a center frequency of 1000Hz. In order to process this analog signal in a digital system, a transformation constant is needed to convert 1000Hz into the corresponding digital frequency.

[0051] In step S113, the target transfer function of each parametric equalizer in the graphic equalizer is determined based on each of the digital frequencies and the analog amplitude at each of the center frequencies.

[0052] The target transfer function describes the mathematical function of the desired input-output relationship of the system and defines the gain at a specific frequency.

[0053] In this embodiment of the disclosure, based on the digital frequencies corresponding to each center frequency and the analog amplitudes at these frequencies, a target transfer function can be defined for each parametric equalizer (typically a bandpass filter) in the graphic equalizer. This function expression describes how the filter adjusts the signal amplitude at the center frequency to achieve the desired spectral shape.

[0054] For example, to convert a center frequency of 200Hz to its corresponding digital frequency, and to achieve a desired amplitude boost of -12dB at that frequency, a bandpass filter can be designed for this center frequency, whose transfer function ensures a -12dB gain at 200Hz. This process is repeated for each center frequency in the graphic equalizer to obtain the target transfer function for the entire equalizer.

[0055] Optionally, in step S111, determining the transformation constant based on the center frequency and the sampling rate includes: Convert each of the aforementioned center frequencies into angular frequencies; In this embodiment of the disclosure, the center frequency describing energy in the spectrum is converted into the rate of change of the periodic phenomenon over time to obtain the corresponding angular frequency.

[0056] The angular frequency can be determined using the following analytical formula. :

[0057] in, π is the center frequency, and π is a mathematical constant.

[0058] The first frequency parameter is determined based on the angular frequencies and the sampling rate. In this embodiment of the disclosure, the first frequency parameter α1 can be determined by the following analytical expression:

[0059] in, The sampling rate.

[0060] The transformation constant is determined based on the first frequency parameter and the sampling rate.

[0061] The transformation constant c can be determined by the following analytical expression:

[0062] It can be explained that, compared to the constants in the bilinear transformation of existing technologies... The condition for its establishment is that That is, it holds true at low frequencies, but a large error will occur at high frequencies. In this disclosure, the corrected transformation constant is always greater than 0, which can ensure that the bilinear transformation is stable for any value, avoid large errors at high frequencies, and thus improve the stability of the entire signal processing.

[0063] Optionally, in step S112, determining the digital frequency corresponding to each of the center frequencies based on the transformation constant, the center frequency, and the sampling rate includes: The second frequency parameter is determined based on the transformation constant and the center frequency; In this embodiment of the disclosure, the transformation constant is determined based on the sampling rate. Therefore, the second frequency parameter can be used to represent the rate of change of the signal in relation to the sampling rate when the periodicity of the angular frequency changes over time.

[0064] The second frequency parameter can be determined using the following analytical expression. :

[0065] in, Let ω be the angular frequency and c be the transformation constant.

[0066] Based on the second frequency parameter and the sampling rate, the digital frequency corresponding to each center frequency is determined.

[0067] In this embodiment of the disclosure, the arctangent value of the second frequency parameter is obtained, and then the product of the arctangent value and the sampling rate is calculated to obtain the digital frequency corresponding to each of the center frequencies. In this way, the angle information of the signal under different conditions can be determined according to the second frequency parameter, and the digital frequency corresponding to each of the center frequencies can be determined according to the sampling rate and the angle information.

[0068] The digital frequency corresponding to each of the center frequencies can be determined by the following analytical formula. :

[0069] in, It involves obtaining the arctangent value of the second frequency parameter.

[0070] Optionally, see Figure 6 As shown, in step S13, determining the target filtering coefficients of each parameter equalizer based on the target transfer function, the center frequency, the sampling rate, the preset bandwidth, and the target gain corresponding to each parameter equalizer includes: In step S131, the target transfer function is transformed into a domain function to obtain the imaginary function of the target transfer function at the angular frequency. Domain function transformation involves converting the target transfer function from one representation (such as the time domain or Laplace domain) to another (such as the angular frequency domain). The imaginary function is the conversion of the complex form of the transfer function in the angular frequency domain into a function containing both real and imaginary parts, which is helpful for analyzing the frequency response characteristics of the system.

[0071] In this embodiment of the disclosure, the target transfer function may be a complex frequency domain function H(s) in the complex frequency domain:

[0072] Where s is a complex frequency variable, To set the gain, the result obtained after converting it from decibels to linearity, i.e. G is used to set the gain. To set quality factors.

[0073] Furthermore, Substituting the values, we can obtain the imaginary function. :

[0074] Where j is the imaginary unit.

[0075] Furthermore, the target gain can be obtained. The expression is:

[0076] In step S132, the setting quality factor in the target transfer function is corrected according to the sampling rate, the target gain, the setting gain in the target transfer function, and the change constant to obtain the target quality factor; Among them, the quality factor (Q factor) is a parameter used to describe the selectivity or sharpness of a filter. A high Q value means that the filter has a sharper response to a specific frequency.

[0077] In this embodiment, the relationship between the target gain and the set gain determines the value of the quality factor. The quality factor of the filter is adjusted based on the sampling rate, the desired gain, and the parameters in the original transfer function. For example, if the equalizer has higher selectivity (i.e., a sharper response) at the center frequency, then the quality factor needs to be increased. This ensures that the actual performance of the filter matches the design target, reducing the deviation between the final true gain value at each center frequency and the target gain.

[0078] In step S133, the target filter coefficients of each of the parameter equalizers are determined based on the target quality factor, the target gain, and the imaginary function.

[0079] The target filter coefficients define the specific implementation process of the filter and determine how the filter responds to the input signal. After determining the filter's quality factor and target gain, these information, along with the transformed imaginary function, can be used to calculate the filter's specific coefficients. These coefficients will be used in the actual implementation of the filter to ensure that the filter's response meets expectations. For example, in an audio processing system, these coefficients may determine how the equalizer adjusts the volume of different frequency components to achieve the desired audio effect.

[0080] Optionally, in step S132, the step of correcting the setting quality factor in the target transfer function based on the sampling rate, the target gain, the setting gain in the target transfer function, and the variation constant to obtain the target quality factor includes: Convert the decibel-domain set gain in the target transfer function to a linear set gain; In audio and signal processing, gain is often expressed in decibels (dB), a logarithmic unit. However, when calculating and correcting parameters such as quality factor, a linear domain gain value is typically required. In this embodiment, G represents the set gain in the decibel domain. The linear set gain can be calculated.

[0081] Determine the magnitude relationship between the linear setting gain and the target gain, and determine the correction expression for correcting the setting quality factor; In this embodiment of the disclosure, the linear set gain and the target gain are compared to determine whether a quality factor correction is needed, and the direction and magnitude of such correction. Based on the result of the gain comparison, a suitable mathematical expression is selected to correct the quality factor. This expression may be a formula or algorithm used to adjust the value of the quality factor according to the gain difference. For example, if the linear set gain is less than the target gain, it may mean that the selectivity of the filter needs to be increased, which typically requires an increase in the quality factor. Therefore, the correction expression may increase the value of the quality factor based on the difference between the two.

[0082] Substituting the sampling rate, the target gain, the set quality factor, the linear set gain, and the transformation constant into the correction expression yields the target quality factor.

[0083] In this embodiment, the known sampling rate, target gain, original set quality factor, linear set gain, and possible transform constant are substituted into the correction expression determined in the second step. The corrected target quality factor is obtained by calculating the correction expression. Assuming a sampling rate of 48kHz, a target gain of 2x (linear domain), an original set quality factor of 1, a linear set gain of 1.5x, and a transform constant of 1, substituting these parameters into the correction expression yields a corrected target quality factor, such as 1.2. This means that the filter selectivity needs to be increased to meet the target gain requirements.

[0084] The target quality factor Q can be determined using the following analytical formula. z :

[0085] In this way, by selecting and adjusting these parameters appropriately, the performance of the system can be precisely controlled and optimized.

[0086] Optionally, determining the target filter coefficients of each of the parameter equalizers based on the target quality factor, the target gain, and the imaginary function includes: Based on the value of the target gain and the imaginary function, determine the coefficient expression of each filter coefficient in each of the parameter equalizers; Specifically, to determine whether the volume should be increased or decreased at the center frequency, a coefficient expression can be derived based on the target gain (i.e., the desired increase or decrease in volume) and the imaginary function (which describes the equalizer's response to different frequencies). This expression can then be used to determine the filter coefficients.

[0087] Substitute the corresponding target quality factors into the coefficient expressions of each filter coefficient in each parameter equalizer to determine the target filter coefficient of each parameter equalizer.

[0088] In this embodiment, a coefficient expression is derived based on the target gain and the imaginary function. A target quality factor (such as the desired higher selectivity of the equalizer at the center frequency) is substituted into this expression. Through calculation, a set of target filter coefficients is obtained, which will be used in the specific implementation of the equalizer to ensure its performance meets our design expectations. For example, if it is desired that the equalizer increase volume at a certain center frequency while maintaining a constant or minimally altered response to other frequencies, this can be achieved by adjusting the filter coefficients.

[0089] The target transfer function can be obtained as the following analytical expression:

[0090] Therefore, the following relationship can be obtained: when hour:

[0091] when hour:

[0092] Based on the calculated gain value Combined with center frequency Sampling rate and bandwidth Using the formula or The formula for calculating the target filter coefficients is used, and the analytical solution is employed. The bandwidth is fixed. In this way, no additional correction is needed for the filter with a high center frequency for any input model.

[0093] Ultimately, the input to the entire system is the desired gain value at the target center frequency, and the output is a set of filter coefficients that make its amplitude-frequency response reach the desired amplitude-frequency response at the target center frequency.

[0094] Optionally, see Figure 7 As shown, in step S12, determining the target gain of each of the parametric equalizers based on the target transfer function and the expected amplitude response at each of the center frequencies includes: In step S121, the complex frequency variables in the target transfer function are replaced to obtain the frequency response of each parameter equalizer; The target transfer function is typically represented by a complex frequency variable (e.g., s = σ + jω, where j is the imaginary unit and ω is the angular frequency). This complex frequency variable can be replaced with a specific frequency value (usually the center frequency) to calculate the system response at that specific frequency. The target transfer function then becomes a function with frequency as its independent variable, i.e., the frequency response function. Furthermore, after replacing it with a complex frequency variable, the amplitude and phase responses of the system at a specific frequency (such as the center frequency) can be calculated.

[0095] In this embodiment of the disclosure, the frequency response of the parametric equalizer can be determined by the following analytical expression. :

[0096] Where m is the m-th parameter equalizer in the graphic equalizer. This represents the frequency response function at the center frequency z.

[0097] In step S122, the target gain of each parameter equalizer is determined based on the frequency response of each parameter equalizer and the desired amplitude response at each center frequency.

[0098] The desired amplitude response is the amplitude response that the system is expected to achieve at a specific frequency (such as the center frequency). It is typically set based on system design requirements or user needs. It can be set using a prototype filter. Furthermore, by comparing the actual frequency response of each equalizer parameter at the center frequency with the desired amplitude response, the target gain that needs adjustment can be calculated.

[0099] For example, suppose the desired amplitude response of the system at 1kHz is 1 (i.e., without changing the signal amplitude), but the actual calculated frequency response amplitude is less than 1. To compensate for this difference, a target gain value greater than 1 can be determined to increase the system's amplitude response at 1kHz when adjusting equalizer parameters later. This target gain value ensures that the actual response of the system at 1kHz is closer to the desired response. As another example, suppose the desired amplitude response of the system at 200Hz is -12, but the actual calculated frequency response amplitude is greater than -12. To compensate for this difference, a target gain value can be determined to decrease the system's amplitude response at 200Hz when adjusting equalizer parameters later. This target gain value ensures that the actual response of the system at 200Hz is closer to the desired response.

[0100] Optionally, in step S122, determining the target gain of each parameter equalizer based on the frequency response of each parameter equalizer and the desired amplitude response at each center frequency includes: Based on the frequency response corresponding to each of the parameter equalizers, determine the amplitude-frequency response of each parameter equalizer in the decibel domain; In this embodiment of the disclosure, the frequency response of each parameter equalizer at a specific frequency (such as the center frequency) can be obtained. This is typically a complex number that includes amplitude and phase information. Since the amplitude response is usually expressed in decibels (dB), it is necessary to convert the amplitude response in the linear domain to the decibel domain.

[0101] Among them, graphic equalizer The frequency response of a series of equalizers with different parameters cascaded together is:

[0102] in, To obtain the cascaded frequency response of the graphic equalizer, the frequency response of each parametric equalizer is multiplied together. It is angular frequency. It represents the number of cascaded parametric equalizers.

[0103] Therefore, the amplitude-frequency response of the graphic equalizer in the decibel (dB) domain is:

[0104] in, This represents the amplitude-frequency response of each parametric equalizer in the decibel (dB) domain.

[0105] Based on the amplitude-frequency response corresponding to each of the parameter equalizers and the reference gain of the reference filter, a target interaction matrix is ​​constructed; The reference filter provides a baseline gain value for comparison with the responses of other equalizers. The interaction matrix describes the mutual influence between different equalizers and between an equalizer and the reference filter. By comparing the amplitude-frequency response of each equalizer with the reference gain, a matrix can be constructed where each element represents the influence of one equalizer on another equalizer or reference filter.

[0106] For example, suppose we have three parametric equalizers A, B, and C, and a reference filter. Through measurement or calculation, we can obtain the decibel-domain amplitude-frequency responses of these three equalizers at the center frequency as -2 dB, -1 dB, and 0 dB, respectively, while the reference gain of the reference filter is 10 dB. We can construct a 4x4 interaction matrix, where the diagonal elements represent the response of each equalizer or reference filter itself, and the off-diagonal elements represent their mutual influence.

[0107] The target gain of each of the parametric equalizers is determined based on the desired amplitude response at each of the center frequencies and the target interaction matrix.

[0108] The desired amplitude response refers to the amplitude response expected to be achieved at each center frequency. By solving a system of linear equations or using optimization algorithms, and combining the desired amplitude response with the interaction matrix, the target gain that each parameter equalizer needs to be adjusted to make the overall system response close to the desired amplitude response.

[0109] Continuing the example above, suppose the desired amplitude response is 0 dB at all center frequencies. Using the previously constructed interaction matrix and the desired amplitude response, we can calculate the target gain adjustments needed for equalizers A, B, and C using mathematical methods (such as least squares, optimization algorithms, etc.) to make the overall response close to 0 dB. For example, the calculation results might indicate that equalizer A needs a 2 dB gain increase, equalizer B needs a 1 dB increase, while equalizer C remains unchanged.

[0110] In this embodiment of the disclosure, the inverse matrix of the target interaction matrix can be calculated, and then the product of the inverse matrix and the desired amplitude response at each of the center frequencies can be calculated to determine the target gain of each of the parameter equalizers.

[0111] Wherein, it is assumed that the desired amplitude response at a specified center frequency is This allows us to calculate the required gain value for each PEQ filter. :

[0112] in, The target interaction matrix.

[0113] Optionally, constructing the target interaction matrix based on the amplitude-frequency response corresponding to each of the parameter equalizers and the reference gain of the reference filter includes: The amplitude-frequency response of each parameter equalizer in the decibel domain is transformed to obtain the transformed amplitude-frequency response corresponding to each parameter equalizer. The amplitude-frequency response in the decibel domain represents the equalizer's ability to adjust the signal amplitude at different frequencies. To construct the interaction matrix, further mathematical transformations of these amplitude-frequency responses may be required. These transformations may include normalization, smoothing, or adjustments based on specific algorithms to better reflect the interactions between equalizers.

[0114] For example, suppose we have three parametric equalizers with dB-domain amplitude-frequency responses of -3 dB, 0 dB, and +2 dB at their center frequencies. To construct the interaction matrix, we might need to normalize these responses to make them all on a common scale. For example, we could subtract a reference value (such as 0 dB) from them all to obtain transformed amplitude-frequency responses of -3 dB, 0 dB, and +2 dB (in this example, normalization does not change the values, but it may be different in more complex cases).

[0115] The target interaction matrix is ​​constructed based on the frequency of each sampled signal within the sampling range, the reference gain of the reference filter, and the transformed amplitude-frequency response of each parameter equalizer.

[0116] Here, the frequency of the sampled signal refers to the frequency of each sampled signal within the sampling range. Combining this information, a matrix can be constructed where each element reflects how the adjustment of one equalizer affects the output of other equalizers or reference filters at different frequencies. This matrix helps reduce the interaction between equalizers and optimize their settings to achieve the desired system response.

[0117] Continuing the example above, consider three equalizers and one reference filter. At each sampled signal frequency, record the transformed amplitude-frequency response of the three equalizers. For example, at 1 kHz, equalizer 1 might attenuate by -3 dB, equalizer 2 might remain unchanged (0 dB), while equalizer 3 might boost by +2 dB. Meanwhile, the reference filter has a gain of 0 dB at 1 kHz. A 4x4 interaction matrix (containing the three equalizers and the reference filter) can be constructed, where the elements of the matrix represent the effect of adjusting one equalizer on the outputs of the other equalizers or the reference filter. For example, if equalizer 1 attenuates by -3 dB at 1 kHz, the corresponding elements in the interaction matrix will reflect the effect of this attenuation on the outputs of the other equalizers and the reference filter.

[0118] In this way, the interaction between various parameter equalizers in the system can be reduced comprehensively, and the equalizer settings can be adjusted as needed to achieve the best system performance.

[0119] Optionally, constructing the target interaction matrix based on the frequency of each sampled signal within the sampling range, the reference gain of the reference filter, and the transformed amplitude-frequency response corresponding to each of the parameter equalizers includes: Based on the transformed frequency domain response of each of the parameter equalizers at different frequencies and the reference gain of the reference filter, the reference decibel gain of each of the reference filters at different frequencies is determined. In this embodiment of the disclosure, the ratio of the transformed frequency domain response of each of the parameter equalizers at different frequencies to the reference gain of the reference filter can be calculated to determine the reference decibel gain of each of the reference filters at different frequencies.

[0120] The target interaction matrix is ​​constructed by using the reference decibel gain of each reference filter at the same frequency in the same column and the reference decibel gain of the same reference filter at different frequencies in the same row.

[0121] Therefore, it is constructed The interaction matrix, which represents A PEQ filter in The interaction between frequencies.

[0122]

[0123] in, , is the subscript of the frequency within the sampling range. , is the subscript of the parametric equalizer (filter) in a graphic equalizer. This is the reference gain of the prototype filter, typically a gain in the decibel domain. dB. It can be calculated using the FFT algorithm.

[0124] In this embodiment, the final input to the entire system is the desired gain value at the target center frequency, and the output is a set of filter coefficients that ensure the amplitude-frequency response reaches the desired amplitude-frequency response at the target center frequency. Using the example from the previous embodiment as input, a set of filter coefficients can be obtained, whose amplitude-frequency response can participate in... Figure 8 As shown, the filter response represented by the curve does not deviate from the expected response at each center frequency represented by the circle.

[0125] This disclosure also provides a signal filtering device, see [link to relevant documentation]. Figure 9 As shown, it includes: The first determining module 1001 is configured to determine the target transfer function of each parameter equalizer in the graphic equalizer based on the sampling rate, each center frequency and the analog amplitude at each center frequency. The second determining module 1002 is configured to determine the target gain of each of the parametric equalizers based on the target transfer function and the expected amplitude response at each of the center frequencies. The third determining module 1003 is configured to determine the target filtering coefficients of each parameter equalizer based on the target transfer function, the center frequency, the sampling rate, the preset bandwidth, and the target gain corresponding to each parameter equalizer. The adjustment module 1004 is configured to adjust the function expression of each of the parameter equalizers with the target filter coefficients corresponding to each parameter equalizer as the target, so as to obtain a target graphic equalizer. The filtering module 1005 is configured to input the acquired signal to be filtered into the target graphic equalizer to obtain the target signal output by the target graphic equalizer after filtering.

[0126] Optionally, the first determining module 1001 is configured to: The transformation constant is determined based on the center frequency and the sampling rate; The digital frequency corresponding to each center frequency is determined based on the transformation constant, the center frequency, and the sampling rate. The target transfer function of each parametric equalizer in the graphic equalizer is determined based on each of the digital frequencies and the analog amplitude at each of the center frequencies.

[0127] Optionally, the first determining module 1001 is configured to: Convert each of the aforementioned center frequencies into angular frequencies; The first frequency parameter is determined based on the angular frequencies and the sampling rate. The transformation constant is determined based on the first frequency parameter and the sampling rate.

[0128] Optionally, the first determining module 1001 is configured to: The second frequency parameter is determined based on the transformation constant and the center frequency; Based on the second frequency parameter and the sampling rate, the digital frequency corresponding to each center frequency is determined.

[0129] Optionally, the third determining module 1003 is configured to: The target transfer function is transformed by a domain function to obtain the imaginary function of the target transfer function at the angular frequency; Based on the sampling rate, the target gain, the set gain in the target transfer function, and the variation constant, the set quality factor in the target transfer function is corrected to obtain the target quality factor; The target filter coefficients of each of the parameter equalizers are determined based on the target quality factor, the target gain, and the imaginary function.

[0130] Optionally, the third determining module 1003 is configured to: Convert the decibel-domain set gain in the target transfer function to a linear set gain; Determine the magnitude relationship between the linear setting gain and the target gain, and determine the correction expression for correcting the setting quality factor; Substituting the sampling rate, the target gain, the set quality factor, the linear set gain, and the transformation constant into the correction expression yields the target quality factor.

[0131] Optionally, the third determining module 1003 is configured to: Based on the value of the target gain and the imaginary function, determine the coefficient expression of each filter coefficient in each of the parameter equalizers; Substitute the corresponding target quality factors into the coefficient expressions of each filter coefficient in each parameter equalizer to determine the target filter coefficient of each parameter equalizer.

[0132] Optionally, the second determining module 1002 is configured to: By replacing the complex frequency variables in the target transfer function, the frequency response of each parameter equalizer is obtained; The target gain of each parameter equalizer is determined based on the frequency response of each parameter equalizer and the desired amplitude response at each center frequency.

[0133] Optionally, the second determining module 1002 is configured to: Based on the frequency response corresponding to each of the parameter equalizers, determine the amplitude-frequency response of each parameter equalizer in the decibel domain; Based on the amplitude-frequency response corresponding to each of the parameter equalizers and the reference gain of the reference filter, a target interaction matrix is ​​constructed; The target gain of each of the parametric equalizers is determined based on the desired amplitude response at each of the center frequencies and the target interaction matrix.

[0134] Optionally, the second determining module 1002 is configured to: The amplitude-frequency response of each parameter equalizer in the decibel domain is transformed to obtain the transformed amplitude-frequency response corresponding to each parameter equalizer. The target interaction matrix is ​​constructed based on the frequency of each sampled signal within the sampling range, the reference gain of the reference filter, and the transformed amplitude-frequency response of each parameter equalizer.

[0135] Optionally, the second determining module 1002 is configured to: Based on the transformed frequency domain response of each of the parameter equalizers at different frequencies and the reference gain of the reference filter, the reference decibel gain of each of the reference filters at different frequencies is determined. The target interaction matrix is ​​constructed by using the reference decibel gain of each reference filter at the same frequency in the same column and the reference decibel gain of the same reference filter at different frequencies in the same row.

[0136] Regarding the apparatus in the above embodiments, the specific manner in which each module performs its operation has been described in detail in the embodiments related to the method, and will not be elaborated upon here.

[0137] This disclosure also provides an electronic device, including: processor; Memory used to store processor-executable instructions; The processor is configured to execute the executable instructions stored in the memory to implement any of the methods described in the foregoing embodiments.

[0138] This disclosure also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of any of the methods described in the foregoing embodiments.

[0139] This disclosure also provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the method described in any of the foregoing embodiments.

[0140] Figure 10 This is a block diagram illustrating an apparatus 800 for coefficient adjustment or filtering according to an exemplary embodiment. (Refer to...) Figure 10 The device 800 may include one or more of the following components: a processing component 802, a memory 804, a power supply component 806, a multimedia component 808, an audio component 810, an input / output interface 812, a sensor component 814, and a communication component 816.

[0141] Processing component 802 typically controls the overall operation of device 800, including operations related to data communication, response operations, and recording operations. Processing component 802 may include one or more processors 820 to execute instructions to complete all or part of the steps of the methods described above. Furthermore, processing component 802 may include one or more modules to facilitate interaction between processing component 802 and other components. For example, processing component 802 may include a multimedia module to facilitate interaction between multimedia component 808 and processing component 802.

[0142] Memory 804 is configured to store various types of data to support the operation of device 800. Examples of this data include instructions for any application or method operating on device 800. Memory 804 can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk.

[0143] Power supply component 806 provides power to various components of device 800. Power supply component 806 may include a power management system, one or more power sources, and other components associated with generating, managing, and distributing power to device 800.

[0144] Multimedia component 808 includes a screen that provides an output interface between the device 800 and the user. In some embodiments, the screen may include a liquid crystal display (LCD) and a touch panel (TP). If the screen includes a touch panel, the screen may be implemented as a touchscreen to receive input signals from the user. The touch panel includes one or more touch sensors to sense touches, swipes, and gestures on the touch panel. The touch sensors may sense not only the boundaries of the touch or swipe action but also the duration and pressure associated with the touch or swipe operation. In some embodiments, multimedia component 808 includes a front-facing camera and / or a rear-facing camera. When the device 800 is in an operating mode, such as a shooting mode or a video mode, the front-facing camera and / or the rear-facing camera may receive external multimedia data. Each front-facing camera and rear-facing camera may be a fixed optical lens system or have focal length and optical zoom capabilities.

[0145] Audio component 810 is configured to output and / or input audio signals. For example, audio component 810 includes a microphone (MIC) configured to receive external audio signals when device 800 is in an operating mode, such as call mode, recording mode, and voice recognition mode. The received audio signals may be further stored in memory 804 or transmitted via communication component 816. In some embodiments, audio component 810 also includes a speaker for outputting audio signals.

[0146] Input / output interface 812 provides an interface between processing component 802 and peripheral interface modules, such as keyboards, click wheels, buttons, etc. These buttons may include, but are not limited to, home buttons, volume buttons, power buttons, and lock buttons.

[0147] Sensor assembly 814 includes one or more sensors for providing status assessments of various aspects of device 800. For example, sensor assembly 814 may detect the on / off state of device 800, the relative positioning of components such as the display and keypad of device 800, changes in the position of device 800 or a component of device 800, the presence or absence of user contact with device 800, the orientation or acceleration / deceleration of device 800, and temperature changes of device 800. Sensor assembly 814 may include a proximity sensor configured to detect the presence of nearby objects without any physical contact. Sensor assembly 814 may also include a light sensor, such as a CMOS or CCD image sensor, for use in imaging applications. In some embodiments, sensor assembly 814 may also include an accelerometer, a gyroscope, a magnetometer, a pressure sensor, or a temperature sensor.

[0148] Communication component 816 is configured to facilitate wired or wireless communication between device 800 and other devices. Device 800 can access wireless networks based on communication standards, such as WiFi, 2G, or 3G, or combinations thereof. In one exemplary embodiment, communication component 816 receives broadcast signals or broadcast-related information from an external broadcast management system via a broadcast channel. In one exemplary embodiment, communication component 816 also includes a near-field communication (NFC) module to facilitate short-range communication. For example, the NFC module may be implemented based on radio frequency identification (RFID) technology, Infrared Data Association (IrDA) technology, ultra-wideband (UWB) technology, Bluetooth (BT) technology, and other technologies.

[0149] In an exemplary embodiment, the apparatus 800 may be implemented by one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), controllers, microcontrollers, microprocessors, or other electronic components to perform the methods described above.

[0150] In an exemplary embodiment, a non-transitory computer-readable storage medium including instructions is also provided, such as a memory 804 including instructions, which can be executed by a processor 820 of the device 800 to perform the above-described method. For example, the non-transitory computer-readable storage medium may be a ROM, random access memory (RAM), CD-ROM, magnetic tape, floppy disk, and optical data storage device, etc.

[0151] In another exemplary embodiment, a computer program product is also provided, the computer program product comprising a computer program executable by a programmable device, the computer program having a code portion for performing the methods described above when executed by the programmable device.

[0152] Those skilled in the art will also understand that the various illustrative logical blocks and steps listed in the embodiments of this application can be implemented by electronic hardware, computer software, or a combination of both. Whether such functionality is implemented through hardware or software depends on the specific application and the overall system design requirements. Those skilled in the art can implement the described functionality using various methods for each specific application, but such implementation should not be construed as exceeding the scope of protection of the embodiments of this application.

[0153] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In this description, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0154] Furthermore, the term “exemplary” is used herein to mean serving as an example, instance, or illustration. Any aspect or design described herein as “exemplary” is not necessarily to be construed as advantageous compared to other aspects or designs. Rather, the use of the term “exemplary” is intended to present the concept in a concrete manner. As used herein, the term “or” is intended to mean an inclusive “or” rather than an exclusive “or.” That is, unless otherwise specified or clear from the context, “X applies A or B” is intended to mean any of the natural inclusive arrangements. That is, “X applies A or B” satisfies any of the foregoing instances if X applies A; X applies B; or both X applies A and B. Additionally, unless otherwise specified or clear from the context to refer to the singular form, the articles “a” and “an” as used in this application and the appended claims are generally understood to mean “one or more.”

[0155] Similarly, although this disclosure has been shown and described with respect to one or more implementations, equivalent variations and modifications will occur to those skilled in the art upon reading and understanding this specification and the accompanying drawings. This disclosure includes all such modifications and variations and is limited only by the scope of the claims. In particular, with respect to the various functions performed by the components described above (e.g., elements, resources, etc.), unless otherwise indicated, the terminology used to describe such components is intended to correspond to any component (functionally equivalent) that performs the specific function of the described component, even if structurally not equivalent to the disclosed structure. Furthermore, although specific features of this disclosure may have been disclosed with respect to only one of several implementations, such features may be combined with one or more other features of other implementations, as may be desired and advantageous to any given or particular application. Moreover, with regard to the terms “comprising,” “owning,” “having,” “having,” or variations thereof as used in the detailed description or claims, such terms are intended to be inclusive in a manner similar to the term “including.”

[0156] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the appended claims.

[0157] It should be understood that this disclosure is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this disclosure is limited only by the appended claims.

Claims

1. A method of signal filtering, characterized by, The method comprises the following steps: determining a target transfer function of each parameter equalizer in a graphic equalizer according to a sampling rate, each center frequency and an analog amplitude at each center frequency; determining a target gain of each parameter equalizer according to the target transfer function and a desired amplitude response at each center frequency; determining a target filter coefficient of each parameter equalizer according to the target transfer function, the center frequency, the sampling rate, a preset bandwidth and the target gain corresponding to each parameter equalizer; adjusting a function expression of each parameter equalizer with the target filter coefficient corresponding to each parameter equalizer as a target to obtain a target graphic equalizer; inputting a to-be-filtered signal obtained to the target graphic equalizer to obtain a target signal output by the target graphic equalizer after filtering.

2. The method of claim 1, wherein, The step of determining the target transfer function of each parameter equalizer in the graphic equalizer according to the sampling rate, each center frequency and the analog amplitude at each center frequency comprises the following steps: determining a transformation constant according to the center frequency and the sampling rate; determining a digital frequency corresponding to each center frequency according to the transformation constant, the center frequency and the sampling rate; determining the target transfer function of each parameter equalizer in the graphic equalizer according to each digital frequency and the analog amplitude at each center frequency.

3. The method of claim 2, wherein, The step of determining the transformation constant according to the center frequency and the sampling rate comprises the following steps: converting each center frequency into an angular frequency; determining a first frequency parameter according to each angular frequency and the sampling rate; determining the transformation constant according to the first frequency parameter and the sampling rate.

4. The method of claim 2, wherein, The step of determining the digital frequency corresponding to each center frequency according to the transformation constant and the center frequency comprises the following steps: determining a second frequency parameter according to the transformation constant and the center frequency; determining the digital frequency corresponding to each center frequency according to the second frequency parameter and the sampling rate.

5. The method of claim 1, wherein, The step of determining the target filter coefficient of each parameter equalizer according to the target transfer function, the center frequency, the sampling rate, the preset bandwidth and the target gain corresponding to each parameter equalizer comprises the following steps: performing a domain function conversion on the target transfer function to obtain a complex function of the target transfer function under an angular frequency; correcting a setting quality factor in the target transfer function according to the sampling rate, the target gain and the setting gain and the variation constant in the target transfer function to obtain a target quality factor; determining the target filter coefficient of each parameter equalizer according to the target quality factor, the target gain and the complex function.

6. The method of claim 5, wherein, The step of correcting the setting quality factor in the target transfer function according to the sampling rate, the target gain and the setting gain in the target transfer function and the variation constant to obtain a target quality factor comprises the following steps: converting the setting gain in decibel domain in the target transfer function into a linear setting gain; determining a size relationship between the linear setting gain and the target gain to determine a correction expression for correcting the setting quality factor; The sampling rate, the target gain, a set quality factor, the linear set gain, and the transform constant are substituted into the correction expression to obtain the target quality factor.

7. The method of claim 5, wherein, The target filter coefficients of the parameter equalizers are determined according to the target quality factor, the target gain, and the imaginary function. A coefficient expression of each filter coefficient in each parameter equalizer is determined according to the value of the target gain and the imaginary function. The target filter coefficients of the parameter equalizers are determined by substituting the corresponding target quality factor into the coefficient expression of each filter coefficient in each parameter equalizer.

8. The method according to any one of claims 1-7, characterized in that, The target gain of each parameter equalizer is determined according to the target transfer function and the expected amplitude response at each center frequency. The frequency response of each parameter equalizer is obtained by replacing the complex frequency variable in the target transfer function. The target gain of each parameter equalizer is determined according to the frequency response of each parameter equalizer and the expected amplitude response at each center frequency.

9. The method of claim 8, wherein, The target gain of each parameter equalizer is determined according to the frequency response of each parameter equalizer and the expected amplitude response at each center frequency. The amplitude-frequency response of each parameter equalizer in the decibel domain is determined according to the corresponding frequency response of each parameter equalizer. The target interaction matrix is constructed according to the corresponding amplitude-frequency response of each parameter equalizer and the reference gain of the reference filter. The target interaction matrix is constructed according to the corresponding amplitude-frequency response of each parameter equalizer and the reference gain of the reference filter.

10. The method of claim 9, wherein, The target interaction matrix is constructed according to the frequency of each sampling signal in the sampling range, the reference gain of the reference filter, and the corresponding transform amplitude-frequency response of each parameter equalizer. The target interaction matrix is constructed according to the frequency of each sampling signal in the sampling range, the reference gain of the reference filter, and the corresponding transform amplitude-frequency response of each parameter equalizer. The target interaction matrix is constructed according to the transform frequency-domain response of each parameter equalizer at different frequencies and the reference gain of the reference filter.

11. The method of claim 10, wherein, The target interaction matrix is constructed by taking the same column as the reference decibel gain of each reference filter at the same frequency and the same row as the reference decibel gain of the same reference filter for different frequencies. The first determination module is configured to determine the target transfer function of each parameter equalizer in the graphic equalizer according to the sampling rate, each center frequency, and the analog amplitude at each center frequency. The second determination module is configured to determine the target gain of each parameter equalizer according to the target transfer function and the expected amplitude response at each center frequency.

12. A signal filtering device, characterized by ​ ​ ​ A third determining module, configured to determine target filter coefficients of each of the parametric equalizers according to the target transfer function, the center frequency, the sampling rate, a preset bandwidth, and the target gain corresponding to each of the parametric equalizers; An adjusting module, configured to adjust a function expression of each of the parametric equalizers with the target filter coefficients corresponding to each of the parametric equalizers as a target, to obtain a target graphic equalizer; A filtering module, configured to input a to-be-filtered signal obtained into the target graphic equalizer, to obtain a target signal output by the target graphic equalizer after filtering.

13. An electronic device, comprising: Comprising: a processor; a memory for storing processor-executable instructions; wherein the processor is configured to execute the executable instructions stored in the memory to implement the method of any one of claims 1-11.

14. A computer-readable storage medium having stored thereon a computer program, characterized in that, The computer program is executed by the processor to implement the steps of the method of any one of claims 1-11.

15. A computer program product, characterised in that, The computer program is executed by the processor to implement the steps of the method of any one of claims 1-11.

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