Digital implementation method of sound effect equalizer, sound effect control circuit, equipment and medium

Abstract

The invention provides a digital implementation method of a sound effect equalizer and a sound effect control circuit, and the method comprises the following steps: obtaining the frequency and gain value of a target sound effect, and drawing a sound effect frequency spectrum curve; acquiring second-order section coefficients of a plurality of designed digital filters; converting the second-order node coefficient into a transfer function; drawing a frequency spectrum curve of the digital filter according to the transfer function; and evaluating a target sound effect through the approximation degree of the sound effect frequency spectrum curve and the digital filter frequency spectrum curve. The invention provides a sound effect control method suitable for a digital circuit, the area is small, the control structure is simple, and the burden of a CPU (Central Processing Unit) is unloaded.

Description

Technical Field

[0001] The present invention relates to the technical field of audio SoC systems, and particularly to a digital implementation method of a sound effect equalizer, a sound effect control circuit, a device, and a medium. Background Art

[0002] Sound effect processing is the most common function of an audio chip, and is usually implemented using an equalizer. The equalizer is used to strengthen or weaken the energy of a certain frequency band to achieve different listening effects. Generally, the horizontal axis is in Octave (interval), and the vertical axis is in dB, and a specific specification curve is customized according to user requirements.

[0003] An interval is a frequency unit. For example, there are 10 intervals from 20 Hz to 20 KHz, which are 20, 40, 80, 160, 320, 640, 1280, 2560, 5120, 10240, 20480 respectively. That is, if one frequency is twice another frequency, it means there is one interval from this frequency to the other frequency. A 1 / 3 interval is to divide an interval into three equal parts. For example, in the range of 20 Hz to 40 Hz, the first frequency is 20 Hz, the next adjustment frequency point is at 20 * 2^(1 / 3) = 25 Hz, the next frequency adjustment point is at 25 * 2^(1 / 3) = 31.5 Hz, and the last frequency adjustment point is at approximately 40 Hz. A 2 / 3 interval is to divide two intervals into three equal parts. For example, in the range of 25 Hz to 100 Hz, it includes two intervals. Then when adjusting the 2 / 3 interval, the first frequency is 25 Hz, the next adjustment frequency point is at 25 * 4^(1 / 3) = 40 Hz, the next frequency adjustment point is at 40 * 4^(1 / 3) = 63 Hz, and the last frequency adjustment point is at approximately 100 Hz. Generally, EQ is done in 1 / 3, 1 / 2, and 1 interval, and the denser the division, the higher the resolution.

[0004] Currently, most sound effect processing on the market is implemented by software, consuming a large amount of CPU computing resources. Therefore, it is necessary to provide a new method to solve the above technical problems. Summary of the Invention

[0005] In order to achieve the above objects and other advantages of the present invention, the first object of the present invention is to provide a digital implementation method of a sound effect equalizer, including the following steps:

[0006] Obtain the frequency and gain value of the target sound effect, and draw a sound effect spectrum curve;

[0007] Obtain the second-order section coefficients of a plurality of designed digital filters;

[0008] Convert the second-order section coefficients into a transfer function;

[0009] Draw a digital filter spectrum curve according to the transfer function;

[0010] Evaluate the target sound effect by the approximation degree between the sound effect spectrum curve and the digital filter spectrum curve.

[0011] Further, the frequencies and gain values of the target sound effect are respectively configured as a frequency vector and a gain vector.

[0012] Further, the step of plotting the sound effect spectrum curve includes:

[0013] Use the data in the frequency vector and the gain vector to draw a line in the current coordinate area.

[0014] Further, the step of converting the second-order section coefficients into a transfer function includes:

[0015] Store the second-order section coefficients of multiple digital filters in a two-dimensional list;

[0016] Call the sos2tf function to convert the data in the two-dimensional list into the form of a transfer function.

[0017] Further, the step of plotting the digital filter spectrum curve according to the transfer function includes:

[0018] Calculate the frequency response of the transfer function and take the absolute value of the frequency response;

[0019] Draw a line in the current coordinate area according to the obtained absolute value.

[0020] Further, the target sound effect is configured as at least one of pop music, rock music, jazz music, classical music, vocals, and low-frequency sound effects.

[0021] Further, the digital filter is configured as a second-order direct form I filter.

[0022] The second object of the present invention is to provide a sound effect control circuit applying the above method.

[0023] The third object of the present invention is to provide a computer device, including a memory, a processor, and a computer program stored on the memory and executable on the processor, and when the processor executes the computer program, the steps of the above method are implemented.

[0024] The fourth object of the present invention is to provide a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the steps of the above method are implemented.

[0025] Compared with the prior art, the beneficial effects of the present invention are:

[0026] The present invention provides an audio effect control method suitable for digital circuit implementation, which has a small area, a simple control structure, and unloads the burden on the CPU.

[0027] The above description is only an overview of the technical solution of the present invention. In order to understand the technical means of the present invention more clearly and implement it according to the content of the specification, the following describes the preferred embodiments of the present invention in detail in conjunction with the accompanying drawings. The specific implementation manners of the present invention are given in detail by the following embodiments and their accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The drawings described herein are used to provide a further understanding of the present invention, form a part of this application, and the schematic embodiments and descriptions of the present invention are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0029] Figure 1 is the curve corresponding to pop music;

[0030] Figure 2 is the curve corresponding to rock music;

[0031] Figure 3 is the curve corresponding to jazz music;

[0032] Figure 4 is the curve corresponding to classical music;

[0033] Figure 5 is the curve corresponding to human voice;

[0034] Figure 6 is the flowchart of the digital implementation method of the audio equalizer;

[0035] Figure 7 is the block diagram of the single-stage Biquad filter;

[0036] Figure 8 is the flowchart of converting the second-order section coefficients into the transfer function;

[0037] Figure 9 is the flowchart of drawing the frequency spectrum curve of the digital filter;

[0038] Figure 10 is the design flowchart of the digital implementation of the audio equalizer;

[0039] Figure 11 is the schematic diagram of the audio frequency spectrum curve and the digital filter frequency spectrum curve of pop music;

[0040] Figure 12 is the schematic diagram of the audio frequency spectrum curve and the digital filter frequency spectrum curve of rock music;

[0041] Figure 13 is the schematic diagram of the audio frequency spectrum curve and the digital filter frequency spectrum curve of jazz music;

[0042] Figure 14 Schematic diagram of the sound effect spectrum curve of classical music and the spectrum curve of the digital filter

[0043] Figure 15 Schematic diagram of the sound effect spectrum curve of human voice and the spectrum curve of the digital filter

[0044] Figure 16 Schematic diagram of a computer device

[0045] Figure 17 Schematic diagram of a computer-readable storage medium Specific implementation manners

[0046] Next, in combination with the accompanying drawings and specific implementation manners, the present invention will be further described. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all embodiments. It should be noted that on the premise of no conflict, the following described embodiments or technical features can be combined arbitrarily to form new embodiments.

[0047] All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0048] In this application, the accompanying drawing numbers are only used to distinguish each step in the solution and are not used to limit the execution order of each step. The specific execution order shall be subject to the description in the specification.

[0049] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0050] Embodiment 1

[0051] A digital implementation method of a sound effect equalizer, as Figure 6 、 Figure 10 shown, includes the following steps:[[]]

[0052] S1. Obtain the frequency and gain value of the target sound effect and draw the sound effect spectrum curve;

[0053] Further, the target sound effect is configured as at least one of pop music, rock music, jazz music, classical music, human voice, and low-frequency sound effect.

[0054] This embodiment mainly studies the implementation of 6 sound effects including pop music, rock music, jazz music, classical music, human voice, and low-frequency sound effect.

[0055] As Figure 1As shown, Pop music requires an even balance between vocals and instruments, so the curve doesn't fluctuate much.

[0056] As Figure 2 shown, Rock music has a significant boost at both the high and low ends. The bass makes the music powerful and rhythmic, and the high notes are clear or even piercing.

[0057] As Figure 3 shown, Jazz music boosts the 3 - 5KHz range to enhance the sense of presence.

[0058] As Figure 4 shown, Classic music also boosts the high and low parts, mainly highlighting the performance of the instruments.

[0059] As Figure 5 shown, in Vocal, the frequency range of the human voice is relatively narrow, mainly concentrated in the mid - frequency part.

[0060] After selecting the implementation range, first, learn the characteristics according to the processing effects of audio processing software on the market. Exemplarily, take Cool Edit software as the learning object. Cool Edit (now known as Adobe Audition) is a powerful multi - track recording and audio processing software developed by Adobe Systems Incorporated in the United States. It was originally developed by Syntrillium Software Corporation and renamed Adobe Audition after being acquired by Adobe in 2003. Cool Edit / Adobe Audition is famous for its excellent audio processing capabilities and rich functions, and is suitable for the professional digital audio production field.

[0061] Exemplarily, the 10 - band sound effect spectrum values of Cool Edit software are shown in the following table.

[0062] Frequency(Hz) 31 62 125 250 500 1K 2K 4K 8K 16K Pop(dB) 4.9 6 3.5 -2.1 -4.2 -0.7 0.7 3.9 4.34 7 Rock(dB) 4.9 4 2 -4 -7 -3 -1 2 6 8 Jazz(dB) 0 0 0 4 4 4 0 2 3 4 Classical(dB) 4.9 3.5 -0.4 -4.9 -8.1 -8.1 -3.2 -1.1 3.2 4.9 Bass(dB) 6 6 6 5.5 3.5 0 0 -1 -4 -7

[0063] From Table 1, several typical frequencies and gain values of Pop can be extracted. Further, the frequencies and gain values of the target sound effect are respectively configured as a frequency vector and a gain vector;

[0064] y = [4.9 6 3.5 -2.1 -4.2 -0.7 0.7 3.9 4.34 7];

[0065] x = [31 62 125 250 500 1000 2000 4000 8000 16000];

[0066] Further, the step of plotting the sound effect spectrum curve includes:

[0067] Use the data in the frequency vector and the gain vector to draw a line in the current coordinate area.

[0068] Specifically, print the x and y corresponding to Pop to matlab and draw them as a blue curve, as Figure 11 shown.

[0069] Correspondingly, several typical frequencies and gain values of Rock can be extracted from Table 1:

[0070] y = [4.9 4 2 -4 -7 -3 -1 2 6 8];

[0071] x = [31 62 125 250 500 1000 2000 4000 8000 16000];

[0072] Print the x and y corresponding to Rock to matlab and draw them as a blue curve, as Figure 12 shown.

[0073] Several typical frequencies and gain values of Jazz can be extracted from Table 1:

[0074] y = [0 0 0 4 4 4 0 2 3 4];

[0075] x = [31 62 125 250 500 1000 2000 4000 8000 16000];

[0076] Print the x and y corresponding to Jazz to matlab and draw them as a blue curve, as Figure 13 shown.

[0077] Several typical frequencies and gain values of Classical can be extracted from Table 1:

[0078] y = [4.9 3.5 -0.4 -4.9 -8.1 -8.1 -3.2 -1.1 3.2 4.9];

[0079] x = [31 62 125 250 500 1000 2000 4000 8000 16000];

[0080] Print the x and y corresponding to Classical to matlab and draw them as a blue curve, as Figure 14 shown.

[0081] Several typical frequencies and gain values of Base can be extracted from Table 1:

[0082] y = [6 6 6 5.5 3.5 0 0 -1 -4 -7];

[0083] x = [31 62 125 250 500 1000 2000 4000 8000 16000];

[0084] Print the x and y corresponding to Base to Matlab and draw them as a blue curve, as Figure 15 shown.

[0085] S2. Obtain the second - order section coefficients of multiple designed digital filters;

[0086] Furthermore, the digital filter is configured as a second - order direct form I filter.

[0087] In this embodiment, the FDATool tool provided by Matlab software is used to design and analyze digital filters. The FDATool tool is a graphical user interface (GUI) tool in Matlab software for filter design and analysis. It allows users to design various types of digital filters, such as low - pass filters, high - pass filters, band - pass filters, and band - stop filters, etc., in an intuitive way.

[0088] Through the FDATool tool, the parameters of the filter can be adjusted, the frequency response of the filter can be observed, and the performance evaluation of the filter can be carried out.

[0089] S3. Convert the second - order section coefficients into a transfer function;

[0090] Furthermore, as Figure 8 shown, the step of converting the second - order section coefficients into a transfer function includes:

[0091] S31. Store the second - order section coefficients of multiple digital filters in a two - dimensional list;

[0092] S32. Call the sos2tf function to convert the data in the two - dimensional list into the form of a transfer function.

[0093] Among them, the function of the sos2tf function is to convert the second - order section data of a digital filter into the form of a transfer function.

[0094] Calling [b,a]=sos2tf(sos) returns the transfer function coefficients of the discrete - time system described by sos.

[0095] As Figure 7As shown, for Pop music, the following is the Biquad direct form I filter designed in this embodiment. Three filters with similar structures are cascaded and printed in red curve in Matlab.

[0096] The second-order section coefficients of the three filters are respectively:

[0097] SOS1 = [16543 -32448 15907 16384 -32448 16065];

[0098] SOS2 = [1000 -1917 921 1024 -1917 897];

[0099] SOS3 = [411 123 -165 256 123 -10];

[0100] Store the second-order section coefficients of the three filters in a two-dimensional list:

[0101] SOS = [SOS1; SOS2; SOS3];

[0102] Call the sos2tf function to convert the data in the two-dimensional list into the transfer function form:

[0103] [B, A] = sos2tf(SOS).

[0104] For Rock music, the following is the Biquad direct form I filter designed in this embodiment. Three filters with similar structures are cascaded and printed in red curve in Matlab.

[0105] The second-order section coefficients of the three filters are respectively:

[0106] SOS1 = [16433 -32645 16216 16384 -32645 16262];

[0107] SOS2 = [991 -1926 939 1024 -1926 906];

[0108] SOS3 = [462 120 -223 256 120 -17];

[0109] Store the second-order section coefficients of the three filters in a two-dimensional list:

[0110] SOS = [SOS1; SOS2; SOS3];

[0111] Call the sos2tf function to convert the data in the two-dimensional list into the transfer function form:

[0112] [B, A] = sos2tf(SOS).

[0113] For Jazz, the following is the Biquad direct form I filter designed in this embodiment. Three filters with similar structures are cascaded and printed in red curve in Matlab.

[0114] The second-order section coefficients of the three filters are respectively:

[0115] SOS1 = [555 -885 334 512 -885 377];

[0116] SOS2 = [245 -427 197 256 -427 186];

[0117] SOS3 = [344 105 -135 256 105 -46];

[0118] Store the second-order section coefficients of the three filters in a two-dimensional list:

[0119] SOS = [SOS1; SOS2; SOS3];

[0120] Call the sos2tf function to convert the data in the two-dimensional list into the transfer function form:

[0121] [B, A] = sos2tf(SOS).

[0122] For Classic, the following is the Biquad direct form I filter designed in this embodiment. Three filters with similar structures are cascaded and printed in red curve in Matlab.

[0123] The second-order section coefficients of the three filters are respectively:

[0124] SOS1 = [16433 -32639 16207 16384 -32639 16256];

[0125] SOS2 = [944 -1775 841 1024 -1775 761];

[0126] SOS3 = [357 123 -111 256 123 -10];

[0127] Store the second-order section coefficients of the three filters in a two-dimensional list:

[0128] SOS = [SOS1; SOS2; SOS3];

[0129] Call the sos2tf function to convert the data in the two-dimensional list into the transfer function form:

[0130] [B, A]=sos2tf(SOS).

[0131] For the low-frequency sound effect (Bass), the following is the Biquad direct type I filter designed in this embodiment. Three filters with similar structures are cascaded and printed in red in matlab.

[0132] The second-order section coefficients of the three filters are respectively:

[0133] SOS1 = [16664 -32205 15542 16384 -32205 15822];

[0134] SOS2 = [1010 -1702 717 1024 -1702 703];

[0135] SOS3 = [163 87 12 256 87 -82];

[0136] Store the second-order section coefficients of the three filters in a two-dimensional list:

[0137] SOS = [SOS1; SOS2; SOS3];

[0138] Call the sos2tf function to convert the data in the two-dimensional list into the transfer function form:

[0139] [B, A]=sos2tf(SOS).

[0140] S4. Draw the digital filter frequency spectrum curve according to the transfer function;

[0141] Further, as Figure 9 shown, the steps of drawing the digital filter frequency spectrum curve according to the transfer function include:

[0142] S41. Calculate the frequency response of the transfer function and find the absolute value of the frequency response;

[0143] Specifically, use the freqz function to calculate the frequency response of the linear system, including the amplitude-frequency response and the phase-frequency response; the basic call format of the freqz function is freqz(b, a). At this time, the function internally defaults to 512-point arithmetic interpolation, so the output is the amplitude value of 512 points and the corresponding independent variable vector from 0 to pi. If you need to change the vector length for easy plotting, you can append dimension information. For example, freqz(b, a, N) performs N-point interpolation; use the abs function to return the absolute value of a number.

[0144] S42. Draw a line in the current coordinate area according to the obtained absolute value.

[0145] Optionally, the program written in Matlab software is as follows:

[0146] figure(1);

[0147] plot(20*log10(abs(freqz(B,A,48000 / 2))), 'r');

[0148] hold on;

[0149] line(x,y);

[0150] zoom on;

[0151] grid on.

[0152] As Figure 11 - Figure 15 shown, the blue curve is the frequency spectrum of the corresponding sound effect of Cool Edit, and the red curve is the frequency spectrum of the filter implemented in this embodiment, which has been quantized to 16-bit integers.

[0153] S5. Evaluate the target sound effect through the approximation degree of the sound effect frequency spectrum curve and the digital filter frequency spectrum curve. That is, through Figure 11 - Figure 15 the approximation degree of the blue curve and the red curve in

[0154] to evaluate the Pop, Rock, Jazz, Classical, and Base sound effects.

[0155] Embodiment 2

[0156] A sound effect control circuit applies the digital implementation method of the sound effect equalizer provided in Embodiment 1. For the detailed description of the method, reference can be made to the corresponding description in the above method embodiment, which will not be elaborated here.

[0157] Embodiment 3

[0158] A computer device 600, as Figure 16 shown, includes a memory 610, a processor 620, and a computer program 630 stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of a digital implementation method of a sound effect equalizer. For the detailed description of the method, reference can be made to the corresponding description in the above method embodiment, which will not be elaborated here.

[0159] Embodiment 4

[0160] A computer-readable storage medium, as Figure 17 shown, on which a computer program is stored, and when the computer program is executed by a processor, the steps of a digital implementation method of an audio equalizer are implemented. For a detailed description of the method, reference may be made to the corresponding description in the above method embodiments, which will not be repeated here.

[0161] The number of devices and the scale of processing described here are used to simplify the description of the present invention. Applications, modifications, and variations of the present invention will be apparent to those skilled in the art.

[0162] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. It can be fully applied to various fields suitable for the present invention. For those skilled in the art, additional modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to specific details and the illustrations shown and described here.

[0163] The device, computer device, non-volatile computer storage medium, and method provided in the embodiments of this specification are corresponding. Therefore, the device, computer device, and non-volatile computer storage medium also have beneficial technical effects similar to the corresponding method. Since the beneficial technical effects of the method have been described in detail above, the beneficial technical effects of the corresponding device, computer device, and non-volatile computer storage medium will not be repeated here.

[0164] Those skilled in the art also know that in addition to implementing the controller in the form of pure computer-readable program code, the method steps can be logically programmed to enable the controller to be implemented in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, embedded microcontrollers, etc. to achieve the same function. Therefore, such a controller can be regarded as a hardware component, and the devices included therein for implementing various functions can also be regarded as the structures within the hardware component. Or even, the devices for implementing various functions can be regarded as either software units for implementing the method or structures within the hardware component.

[0165] The system, device, or unit illustrated in the above embodiments can be specifically implemented by a computer chip or entity, or by a product with a certain function. For the convenience of description, the above device is described by dividing it into various units according to functions. Of course, when implementing one or more embodiments of this specification, the functions of each unit can be implemented in the same or multiple software and / or hardware.

[0166] Those skilled in the art should understand that the embodiments of this specification can be provided as a method, a system, or a computer program product. Therefore, the embodiments of this specification can take the form of an all-hardware embodiment, an all-software embodiment, or an embodiment combining software and hardware aspects. Moreover, the embodiments of this specification can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0167] This specification is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to the embodiments of this specification. It should be understood that each flow and / or block in the flowchart and / or block diagram, and the combination of flows and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, such that the instructions executed by the processor of the computer or other programmable data processing devices generate means for implementing the functions specified in Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0168] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, such that the instructions stored in the computer-readable memory generate a manufactured article including instruction means that implement the functions specified in Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0169] These computer program instructions can also be loaded onto a computer or other programmable data processing device, such that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process, and thus the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0170] It should also be noted that the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, such that a process, method, commodity or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, commodity or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, commodity or device comprising said element.

[0171] This specification may be described in the general context of computer-executable instructions executed by a computer, such as program units. Generally, program units include routines, programs, objects, components, data structures, etc. that perform specific tasks or implement specific abstract data types. The specification may also be practiced in a distributed computing environment where tasks are performed by remote processing devices connected through a communication network. In a distributed computing environment, program units may be located in local and remote computer storage media including storage devices.

[0172] Each embodiment in this specification is described in a progressive manner. For the parts that are the same or similar among the embodiments, reference can be made to each other. Each embodiment focuses on the differences from other embodiments. In particular, for system embodiments, since they are basically similar to method embodiments, the description is relatively simple, and reference can be made to the relevant parts of the method embodiments for the related parts.

[0173] The above is only for the embodiments of this specification and is not intended to limit one or more embodiments of this specification. For those skilled in the art, various changes and modifications can be made to one or more embodiments of this specification. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of one or more embodiments of this specification shall be included within the scope of the claims of one or more embodiments of this specification.

Claims

1. A digital implementation method of a sound equalizer, characterized in that, Including the following steps: Obtain the frequency and gain value of the target sound effect, and draw the sound effect spectrum curve; Obtain the second-order section coefficients of multiple designed digital filters; Convert the second-order section coefficients into transfer functions; Draw the digital filter spectrum curve according to the transfer function; Evaluate the target sound effect according to the approximation degree of the sound effect spectrum curve and the digital filter spectrum curve.

2. The digital implementation method of an audio equalizer according to claim 1, characterized in that: The frequency and gain value of the target sound effect are respectively configured as a frequency vector and a gain vector.

3. The digital implementation method of an audio equalizer as described in claim 2, wherein The step of drawing the sound effect spectrum curve includes: Use the data in the frequency vector and the gain vector to draw a line in the current coordinate area.

4. The digital implementation method of an audio equalizer as claimed in claim 1, wherein, The step of converting the second-order section coefficients into transfer functions includes: Store the second-order section coefficients of multiple digital filters in a two-dimensional list; Call the sos2tf function to convert the data in the two-dimensional list into the form of a transfer function.

5. The digital implementation method of an audio equalizer according to claim 3, characterized in that, The step of drawing the digital filter spectrum curve according to the transfer function includes: Calculate the frequency response of the transfer function and obtain the absolute value of the frequency response; Draw a line in the current coordinate area according to the obtained absolute value.

6. The digital implementation method of an audio equalizer according to claim 1, characterized in that: The target sound effect is configured as at least one of pop music, rock music, jazz music, classical music, human voice, and low-frequency sound effect.

7. The digital implementation method of an audio equalizer as claimed in claim 1, characterized in that: The digital filter is configured as a second-order direct form I filter.

8. An audio effect control circuit, characterized in that, Apply the method according to any one of claims 1 to 7.

9. A computer device, comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the method according to any one of claims 1 to 7.

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