Filtering method and device

Abstract

The application discloses a filtering method and device. The method divides each low-frequency signal in a first input signal into at least two layers of low-frequency signals based on a first parameter value of each low-frequency signal; and performs high-pass filtering processing on each low-frequency signal based on a cutoff frequency corresponding to each low-frequency signal in the at least two layers of low-frequency signals. The at least two layers of low-frequency signals include a first layer of low-frequency signals and a second layer of low-frequency signals. The first parameter value of each low-frequency signal in the second layer of low-frequency signals is greater than the first parameter value of each low-frequency signal in the first layer of low-frequency signals, and the cutoff frequency corresponding to each low-frequency signal in the second layer of low-frequency signals is less than the cutoff frequency corresponding to each low-frequency signal in the first layer of low-frequency signals. As a result, each low-frequency signal in the first layer of low-frequency signals is attenuated more, and each low-frequency signal in the second layer of low-frequency signals is attenuated less, so that the power consumption is reduced, and the damage to the sound quality of the first input signal is reduced.

Description

Technical Field

[0001] The present application relates to the field of signal processing technology, and in particular to a filtering method and device. Background Art

[0002] With the development of semiconductor integrated circuits, digital power amplifiers (DSPs) have become the mainstream of future development due to their advantages such as high output power, high efficiency, and small size. In the tuning algorithm of a DSP, the input signal is often subjected to high-pass filtering according to actual needs. However, when using existing filtering methods to perform high-pass filtering on the input signal, if the cutoff frequency is set high, the input signal is significantly attenuated, and power consumption is significantly reduced, but the sound quality of the input signal is easily damaged. If the cutoff frequency is set low, although the sound quality of the input signal can be guaranteed, the power consumption reduction is not significant. Therefore, when performing high-pass filtering on the input signal, how to achieve both reduced power consumption and reduced damage to the sound quality of the input signal is a technical problem that needs to be solved urgently by those skilled in the art. Summary of the Invention

[0003] To solve the above technical problems, the embodiments of the present application provide a filtering method and device to achieve the purpose of reducing power consumption and minimizing damage to the sound quality of the input signal when performing high-pass filtering on the input signal.

[0004] To achieve the above objectives, the present invention provides the following technical solutions:

[0005] A filtering method, comprising:

[0006] dividing each low-frequency signal in the first input signal into at least two layers of low-frequency signals based on a first parameter value of each low-frequency signal in the first input signal, wherein the first parameter value of the low-frequency signal represents the strength of the low-frequency signal;

[0007] determining a cutoff frequency corresponding to each low-frequency signal in the at least two layers of low-frequency signals based on a first parameter value of each low-frequency signal in the at least two layers of low-frequency signals;

[0008] performing high-pass filtering on each low-frequency signal in the first input signal based on a cutoff frequency corresponding to each low-frequency signal in the at least two layers of low-frequency signals;

[0009] Among them, the at least two layers of low-frequency signals include a first layer of low-frequency signals and a second layer of low-frequency signals, the first parameter value of each low-frequency signal in the second layer of low-frequency signals is greater than the first parameter value of each low-frequency signal in the first layer of low-frequency signals, and the cutoff frequency corresponding to each low-frequency signal in the second layer of low-frequency signals is less than the cutoff frequency corresponding to each low-frequency signal in the first layer of low-frequency signals.

[0010] Optionally, the cutoff frequencies corresponding to the low-frequency signals in the first layer are the same.

[0011] Optionally, the cutoff frequencies corresponding to the low-frequency signals in the first layer are the same.

[0012] Optionally, the cutoff frequencies corresponding to the low-frequency signals in the first layer decrease with the increase of the first parameter values of the low-frequency signals.

[0013] Optionally, the cutoff frequencies corresponding to the low-frequency signals in the second layer are different.

[0014] Optionally, the cutoff frequencies corresponding to the low-frequency signals in the second layer decrease with the increase of the first parameter values of the low-frequency signals.

[0015] Optionally, the at least two layers of low-frequency signals further include a third layer of low-frequency signals, and the first parameter values of the low-frequency signals in the third layer are greater than the first parameter values of the low-frequency signals in the second layer.

[0016] The cutoff frequencies corresponding to the low-frequency signals in the third layer are not greater than the cutoff frequencies corresponding to the low-frequency signals in the second layer.

[0017] Optionally, the cutoff frequencies corresponding to the low-frequency signals in the third layer are the same, or the cutoff frequencies corresponding to the low-frequency signals in the third layer increase with the increase of the first parameter values of the low-frequency signals.

[0018] Optionally, the at least two layers of low-frequency signals further include a third layer of low-frequency signals, and the first parameter values of the low-frequency signals in the third layer are greater than the first parameter values of the low-frequency signals in the second layer.

[0019] The cutoff frequencies corresponding to the low-frequency signals in the third layer are greater than the cutoff frequencies corresponding to at least part of the low-frequency signals in the second layer, and are less than the cutoff frequencies corresponding to the low-frequency signals in the first layer.

[0020] Optionally, the cutoff frequencies corresponding to the low-frequency signals in the third layer increase with the increase of the first parameter values of the low-frequency signals.

[0021] Optionally, determining the cutoff frequencies corresponding to the low-frequency signals in the at least two layers of low-frequency signals based on the first parameter values of the low-frequency signals in the at least two layers of low-frequency signals comprises:

[0022] Querying a database based on the first parameter values of the low-frequency signals in the at least two layers of low-frequency signals to determine the cutoff frequencies corresponding to the low-frequency signals in the at least two layers of low-frequency signals.

[0023] Optionally, the method for establishing the database includes:

[0024] dividing each low-frequency signal in the second input signal into at least two layers of low-frequency signals based on a first parameter value of each low-frequency signal in the second input signal, wherein the first parameter value of the low-frequency signal represents the strength of the low-frequency signal;

[0025] determining a cutoff frequency corresponding to each low-frequency signal in the at least two layers of low-frequency signals based on a first parameter value of each low-frequency signal in the at least two layers of low-frequency signals;

[0026] performing high-pass filtering on each low-frequency signal in the second input signal based on a cutoff frequency corresponding to each low-frequency signal in the at least two layers of low-frequency signals to obtain an output signal;

[0027] Playing the output signal and determining the sound playback quality of the output signal;

[0028] If the sound playback quality of the output signal does not meet the preset requirements, based on the sound playback quality of the output signal, the cutoff frequency corresponding to each low-frequency signal in the at least two layers of low-frequency signals is adjusted until the sound playback quality of the output signal meets the preset requirements.

[0029] Optionally, before dividing each low-frequency signal in the first input signal into at least two layers of low-frequency signals based on the first parameter value of each low-frequency signal in the first input signal, the method further includes:

[0030] Performing low-pass filtering on the first input signal to obtain low-frequency signals in the first input signal;

[0031] Each low-frequency signal in the first input signal is detected to obtain a first parameter value of each low-frequency signal in the first input signal.

[0032] Optionally, the first parameter value of the low-frequency signal includes: at least one of multiple amplitude parameter values ​​of the low-frequency signal, and / or at least one of multiple energy parameter values ​​of the low-frequency signal.

[0033] A filtering device, comprising: a controller and a high-pass filter; wherein,

[0034] The controller is configured to divide each low-frequency signal in the first input signal into at least two layers of low-frequency signals based on a first parameter value of each low-frequency signal in the first input signal, wherein the first parameter value of the low-frequency signal represents the strength of the low-frequency signal; and to determine a cutoff frequency corresponding to each low-frequency signal in the at least two layers of low-frequency signals based on the first parameter value of each low-frequency signal in the at least two layers of low-frequency signals, and output the determined cutoff frequency corresponding to each low-frequency signal in the at least two layers of low-frequency signals to the high-pass filter;

[0035] The high-pass filter is configured to perform high-pass filtering on each low-frequency signal in the first input signal based on a cutoff frequency corresponding to each low-frequency signal in the at least two layers of low-frequency signals;

[0036] Among them, the at least two layers of low-frequency signals include a first layer of low-frequency signals and a second layer of low-frequency signals, the first parameter value of each low-frequency signal in the second layer of low-frequency signals is greater than the first parameter value of each low-frequency signal in the first layer of low-frequency signals, and the cutoff frequency corresponding to each low-frequency signal in the second layer of low-frequency signals is less than the cutoff frequency corresponding to each low-frequency signal in the first layer of low-frequency signals.

[0037] Optionally, the device further comprises: a low-pass filter and a detector; wherein,

[0038] The low-pass filter is configured to perform low-pass filtering on the first input signal to obtain low-frequency signals in the first input signal, and output the low-frequency signals in the first input signal to the detector;

[0039] The detector is used to detect each low-frequency signal in the first input signal, obtain a first parameter value of each low-frequency signal in the first input signal, and output the first parameter value of each low-frequency signal in the first input signal to the controller.

[0040] Compared with the existing technology, the above technical solution has the following advantages:

[0041] The filtering method provided in the embodiment of the present application includes: dividing each low-frequency signal in a first input signal into at least two layers of low-frequency signals based on a first parameter value of each low-frequency signal in the first input signal, wherein the first parameter value of the low-frequency signal represents the strength of the low-frequency signal; determining a cutoff frequency corresponding to each low-frequency signal in the at least two layers of low-frequency signals based on the first parameter value of each low-frequency signal in the at least two layers of low-frequency signals; performing high-pass filtering on each low-frequency signal in the first input signal based on the cutoff frequency corresponding to each low-frequency signal in the at least two layers of low-frequency signals; wherein the at least two layers of low-frequency signals include a first parameter value of each low-frequency signal in the at least two layers of low-frequency signals. A layer of low-frequency signals and a second layer of low-frequency signals, wherein the first parameter value of each low-frequency signal in the second layer of low-frequency signals is greater than the first parameter value of each low-frequency signal in the first layer of low-frequency signals, and the cutoff frequency corresponding to each low-frequency signal in the second layer of low-frequency signals is less than the cutoff frequency corresponding to each low-frequency signal in the first layer of low-frequency signals, so that each low-frequency signal in the first layer of low-frequency signals is attenuated more, thereby significantly reducing power consumption, while each low-frequency signal in the second layer of low-frequency signals is attenuated less, thereby reducing damage to the sound quality of the first input signal, thereby achieving the purpose of both reducing power consumption and reducing damage to the sound quality of the input signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0043] Figure 1 A flowchart of a filtering method provided in one embodiment of the present application;

[0044] Figure 2 A schematic diagram of a flow chart of dividing each low-frequency signal in a first input signal into at least two layers of low-frequency signals in a filtering method provided in another embodiment of the present application;

[0045] Figure 3 A schematic diagram of a change relationship between the cutoff frequency corresponding to each low-frequency signal in the first input signal and the increase of the first parameter value of each low-frequency signal;

[0046] Figure 4 is another schematic diagram of a change relationship of the cutoff frequency corresponding to each low-frequency signal in the first input signal as the first parameter value of each low-frequency signal increases;

[0047] Figure 5is another schematic diagram of a change relationship of the cutoff frequency corresponding to each low-frequency signal in the first input signal as the first parameter value of each low-frequency signal increases;

[0048] Figure 6 is a schematic diagram of another variation relationship of the cutoff frequency corresponding to each low-frequency signal in the first input signal as the first parameter value of each low-frequency signal increases;

[0049] Figure 7 A flowchart of a method for establishing a database;

[0050] Figure 8 A flowchart of a filtering method provided in yet another embodiment of the present application;

[0051] Figure 9 A schematic structural diagram of a filtering device provided in one embodiment of the present application;

[0052] Figure 10 This is a schematic structural diagram of a filtering device provided in another embodiment of the present application. DETAILED DESCRIPTION

[0053] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0054] In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application may also be implemented in other ways different from those described herein. Those skilled in the art may make similar generalizations without violating the connotation of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0055] Secondly, this application is described in detail with reference to schematic diagrams. When describing the embodiments of this application, for ease of explanation, cross-sectional views of device structures may be partially enlarged and not to scale. Furthermore, these schematic diagrams are merely illustrative and should not limit the scope of protection of this application. Furthermore, in actual production, three-dimensional dimensions, including length, width, and depth, should be included.

[0056] As described in the background technology section, when the input signal is high-pass filtered using the existing filtering method, if the cutoff frequency is set higher, the input signal will be attenuated more and the power consumption will be significantly reduced, but the sound quality of the input signal will be easily damaged. If the cutoff frequency is set lower, although the sound quality of the input signal can be guaranteed, the power consumption reduction is not obvious. Therefore, when the input signal is high-pass filtered, how to achieve both reducing power consumption and reducing damage to the sound quality of the input signal is a technical problem that needs to be urgently solved by technical personnel in this field.

[0057] In view of this, the embodiment of the present application provides a filtering method, such as Figure 1 As shown, the method includes:

[0058] S1: Divide each low-frequency signal in a first input signal into at least two layers of low-frequency signals based on a first parameter value of each low-frequency signal in the first input signal, wherein the first parameter value of the low-frequency signal represents the strength of the low-frequency signal.

[0059] Specifically, in one embodiment of the present application, the first parameter value of the low-frequency signal includes: at least one of a plurality of amplitude parameter values ​​of the low-frequency signal, and / or at least one of a plurality of energy parameter values ​​of the low-frequency signal, wherein the amplitude parameter value of the low-frequency signal includes: sound pressure value (Pa), voltage value (V), acceleration value (m / s 2 ), etc. The energy parameter values ​​of the low-frequency signal include: sound power value (W), sound intensity value (W / m 2 )wait.

[0060] Considering that in practical applications, the amplitude parameter value or energy parameter value of the audio signal is often converted into a decibel value to more intuitively represent the intensity of the audio signal, therefore, based on the above embodiment, in one embodiment of the present application, Figure 2 As shown, based on the first parameter value of each low-frequency signal in the first input signal, dividing each low-frequency signal in the first input signal into at least two layers of low-frequency signals includes:

[0061] S11: converting the first parameter value of each low-frequency signal in the first input signal into a decibel value based on the first parameter value of each low-frequency signal in the first input signal and a preset reference value;

[0062] S12: Divide each low-frequency signal in the first input signal into at least two layers of low-frequency signals based on the decibel value corresponding to the first parameter value of each low-frequency signal in the first input signal.

[0063] Specifically, when the first parameter value of the low-frequency signal is an amplitude parameter value, the formula used to convert the amplitude parameter value of the low-frequency signal into a decibel value is:

[0064]

[0065] Wherein, X is the amplitude parameter value of the low-frequency signal, and X0 is the preset reference value corresponding to the amplitude parameter value of the low-frequency signal.

[0066] When the first parameter value of the low-frequency signal is an energy parameter value, the formula used to convert the energy parameter value of the low-frequency signal into a decibel value is:

[0067]

[0068] Wherein, W is the energy parameter detection value of the low-frequency signal, and W0 is the preset reference value corresponding to the energy parameter value of the low-frequency signal.

[0069] It should be noted that, for different first input signals, although the intensity distribution of the low-frequency signals contained therein is not quite the same, the inventors have found that, in different first input signals, the intensities of the low-frequency signals containing more important information such as musical instruments and human voices are generally larger, and these low-frequency signals with larger intensities have an important impact on the sound quality of the first input signal, while the intensities of the low-frequency signals containing fewer important information such as musical instruments and human voices are generally smaller, and the greater attenuation of these low-frequency signals with smaller intensities will not affect the sound quality of the first input signal. Therefore, the filtering method provided in the embodiment of the present application utilizes the first parameter value of the low-frequency signal to characterize the intensity of the low-frequency signal, thereby dividing the low-frequency signals in the first input signal into at least two layers of low-frequency signals based on the first parameter value of each low-frequency signal in the first input signal, so that different cutoff frequencies can be determined subsequently to perform high-pass filtering on the low-frequency signals of different layers.

[0070] S2: determining a cutoff frequency corresponding to each low-frequency signal in the at least two layers of low-frequency signals based on a first parameter value of each low-frequency signal in the at least two layers of low-frequency signals;

[0071] S3: Performing high-pass filtering on each low-frequency signal in the first input signal based on a cutoff frequency corresponding to each low-frequency signal in the at least two layers of low-frequency signals.

[0072] In the embodiment of the present application, the at least two layers of low-frequency signals include a first layer of low-frequency signals and a second layer of low-frequency signals. Specifically, Figure 3 As shown, Figure 3A schematic diagram is provided of a changing relationship of the cutoff frequency corresponding to each low-frequency signal in the first input signal as the first parameter value of each low-frequency signal increases, wherein the first parameter value V of each low-frequency signal in the first layer of low-frequency signals ranges from V_min to V1, and the first parameter value V of each low-frequency signal in the second layer of low-frequency signals ranges from V1 to V_max. As can be seen from the figure, the first parameter value of each low-frequency signal in the second layer of low-frequency signals is greater than the first parameter value of each low-frequency signal in the first layer of low-frequency signals, and the cutoff frequency corresponding to each low-frequency signal in the second layer of low-frequency signals is less than the cutoff frequency corresponding to each low-frequency signal in the first layer of low-frequency signals.

[0073] It should be noted that, since the first input signal contains more important information such as musical instruments and human voices, the intensity of each low-frequency signal is generally larger, and the intensity of each low-frequency signal containing less important information such as musical instruments and human voices is generally smaller, and the first parameter value of each low-frequency signal in the second layer of low-frequency signals is greater than the first parameter value of each low-frequency signal in the first layer of low-frequency signals, indicating that the intensity of each low-frequency signal in the second layer of low-frequency signals is greater than the intensity of each low-frequency signal in the first layer of low-frequency signals, therefore, the low-frequency signals in the first input signal that contain more important information such as musical instruments and human voices will be mainly concentrated in the second layer of low-frequency signals, while the low-frequency signals in the first input signal that contain less important information such as musical instruments and human voices will be mainly concentrated in the second layer of low-frequency signals. It will be mainly concentrated in the first layer of low-frequency signals, and then determine that the cutoff frequency corresponding to each low-frequency signal in the second layer of low-frequency signals is smaller than the cutoff frequency corresponding to each low-frequency signal in the first layer of low-frequency signals, so that when high-pass filtering is performed on each low-frequency signal in the first input signal based on the cutoff frequency corresponding to each low-frequency signal in the at least two layers of low-frequency signals, each low-frequency signal in the first layer of low-frequency signals can be attenuated more, thereby significantly reducing power consumption without affecting the sound quality of the first input signal, while each low-frequency signal in the second layer of low-frequency signals is attenuated less, thereby reducing damage to the sound quality of the first input signal, thereby achieving the purpose of both reducing power consumption and reducing damage to the sound quality of the input signal.

[0074] Based on the above embodiment, optionally, in one embodiment of the present application, continue as follows Figure 3 As shown, each low-frequency signal in the first layer of low-frequency signals ( Figure 3 The cutoff frequency corresponding to each low-frequency signal (where the first parameter value V ranges from V_min to V1) is the same, which is a higher value fc_max.

[0075] In another embodiment of the present application, the cutoff frequencies corresponding to at least some of the low-frequency signals in the first layer of low-frequency signals are different, that is, the cutoff frequencies corresponding to some of the low-frequency signals in the first layer of low-frequency signals may be the same, while the cutoff frequencies corresponding to another part of the low-frequency signals are different, or the cutoff frequencies corresponding to each low-frequency signal may be different. The present application does not impose any limitation on this, and the specific cutoff frequencies may be determined according to the tuning requirements of the first input signal.

[0076] It should be noted that when the cutoff frequencies corresponding to at least part of the low-frequency signals in the first layer of low-frequency signals are different, the cutoff frequencies corresponding to these part of the low-frequency signals may increase as the first parameter value of these part of the low-frequency signals increases, or may decrease as the first parameter value of these part of the low-frequency signals increases. This application does not limit this, and the specific cutoff frequencies may be determined according to the tuning requirements of the first input signal.

[0077] Since each low-frequency signal in the first layer of low-frequency signals contains less important information such as musical instruments and human voices, in general, the cutoff frequency corresponding to each low-frequency signal in this layer can be determined to be a higher value, so that the low-frequency signals in this layer are attenuated more, thereby significantly reducing power consumption without affecting the sound quality of the first input signal.

[0078] However, if the sound effects of the low-frequency signals in the first layer of low-frequency signals whose first parameter values ​​are greater than a certain threshold also have a significant impact on the sound quality of the first input signal, then using a higher cutoff frequency for high-pass filtering of the low-frequency signals in the first layer of low-frequency signals will cause damage to the sound quality of the low-frequency signals in the first layer of low-frequency signals whose first parameter values ​​are greater than the threshold. On the other hand, using a lower cutoff frequency for high-pass filtering of the low-frequency signals in the first layer of low-frequency signals will not significantly reduce the power consumption of the low-frequency signals in the first layer of low-frequency signals whose first parameter values ​​are less than the threshold. Therefore, , it is necessary to determine the cutoff frequency corresponding to each low-frequency signal in the first layer of low-frequency signals based on the first parameter value of each low-frequency signal in the first layer of low-frequency signals, so that the cutoff frequencies corresponding to at least some of the low-frequency signals in the first layer of low-frequency signals are different, wherein, for each low-frequency signal in the first layer of low-frequency signals whose first parameter value is less than the threshold, a corresponding higher cutoff frequency can be determined, and for each low-frequency signal in the first layer of low-frequency signals whose first parameter value is greater than the threshold, a corresponding different cutoff frequency can be determined, thereby achieving the purpose of reducing power consumption and reducing damage to the sound quality of the first input signal. It should be noted that the present application does not limit the threshold value, and the specific threshold value needs to be determined according to the situation of each low-frequency signal of the first input signal.

[0079] Optionally, in one embodiment of the present application, the influence of the sound effect of each low-frequency signal in the first layer of low-frequency signals on the sound quality of the first input signal increases with the increase of the intensity of each low-frequency signal (that is, the first parameter value of each low-frequency signal). Therefore, the cutoff frequencies corresponding to at least some of the low-frequency signals in the first layer of low-frequency signals may be different:

[0080] The cutoff frequency corresponding to each low-frequency signal in the first layer of low-frequency signals decreases as the first parameter value of each low-frequency signal increases, so as to reduce damage to the sound quality of the first input signal.

[0081] Based on the above embodiment, optionally, in one embodiment of the present application, as Figure 4 As shown, Figure 4 A schematic diagram of another changing relationship of the cutoff frequency corresponding to each low-frequency signal in the first input signal as the first parameter value of each low-frequency signal increases is given, wherein the first parameter value V of each low-frequency signal in the first layer of low-frequency signals ranges from V_min to V2, and the cutoff frequency corresponding to each low-frequency signal in the first layer of low-frequency signals decreases linearly as the first parameter value of each low-frequency signal increases. However, the present application does not limit this. In other embodiments of the present application, the cutoff frequency corresponding to each low-frequency signal in the first layer of low-frequency signals can also decrease in a curve as the first parameter value of each low-frequency signal increases, depending on the specific circumstances. It should be noted that the present application does not limit the slope of the decrease in the cutoff frequency corresponding to each low-frequency signal in the first layer of low-frequency signals as the first parameter value of each low-frequency signal increases, and the specific slope can be determined according to the tuning requirements of the first input signal.

[0082] It should be noted that, in the above embodiment, when the sound effects of each low-frequency signal whose first parameter value in the first layer of low-frequency signals is greater than a certain threshold value also have a relatively important impact on the sound quality of the first input signal, it is necessary to appropriately reduce the cutoff frequency corresponding to each low-frequency signal whose first parameter value in the first layer of low-frequency signals is greater than the threshold value to reduce the damage to the sound quality of the first input signal, since the cutoff frequency corresponding to each low-frequency signal in the second layer of low-frequency signals is lower than the cutoff frequency corresponding to each low-frequency signal in the first layer of low-frequency signals, the cutoff frequency corresponding to each low-frequency signal in the second layer of low-frequency signals also needs to be appropriately reduced.

[0083] Since each low-frequency signal in the second layer of low-frequency signals contains a large amount of important information such as musical instruments and human voices, using a higher cutoff frequency to perform high-pass filtering on each low-frequency signal in the second layer of low-frequency signals will cause damage to the sound quality of the second input signal. However, using a lower cutoff frequency to perform high-pass filtering on each low-frequency signal in the second layer of low-frequency signals will not significantly reduce power consumption. In other words, using the same cutoff frequency for each low-frequency signal in the second layer of low-frequency signals cannot achieve both the goals of reducing power consumption and reducing damage to the sound quality of the first input signal. It is necessary to determine the cutoff frequency corresponding to each low-frequency signal in the second layer of low-frequency signals based on the first parameter value of each low-frequency signal in the second layer of low-frequency signals, so that the cutoff frequency corresponding to each low-frequency signal in the second layer of low-frequency signals is different. Specifically, a higher cutoff frequency can be determined for each low-frequency signal in the second layer of low-frequency signals with a smaller first parameter value, and a lower cutoff frequency can be determined for each low-frequency signal in the second layer of low-frequency signals with a larger first parameter value. This achieves the goals of both reducing power consumption and reducing damage to the sound quality of the first input signal.

[0084] Optionally, in one embodiment of the present application, the cutoff frequencies corresponding to the low-frequency signals in the second layer of low-frequency signals may be different:

[0085] The cutoff frequency corresponding to each low-frequency signal in the second layer of low-frequency signals decreases as the first parameter value of each low-frequency signal increases.

[0086] Based on the above embodiment, optionally, in one embodiment of the present application, continue as follows Figure 4 As shown, the first parameter value V of each low-frequency signal in the second layer of low-frequency signals ranges from V2 to V3, and the cutoff frequency corresponding to each low-frequency signal in the second layer of low-frequency signals decreases linearly with the increase of the first parameter value of each low-frequency signal; in another embodiment of the present application, Figure 3 As shown, the first parameter value V of each low-frequency signal in the second layer of low-frequency signals ranges from V1 to V_max, and the cutoff frequency corresponding to each low-frequency signal in the second layer of low-frequency signals decreases as the first parameter value of each low-frequency signal increases. This application does not impose any restrictions on this, and the specific situation depends on the application. It should be noted that this application does not impose any restrictions on the slope of the cutoff frequency corresponding to each low-frequency signal in the second layer of low-frequency signals as the first parameter value of each low-frequency signal increases. The specific slope can be determined according to the tuning requirements of the first input signal.

[0087] Furthermore, for the low-frequency signals in the first input signal that contain more important information such as musical instruments and human voices, the tuning requirements of the human voice also need to be considered. If the human voice accounts for a large proportion in the low-frequency signal, the cutoff frequency corresponding to the low-frequency signal needs to be appropriately raised so that the low-frequency signal can be high-pass filtered using the raised cutoff frequency to make the human voice thinner and crisper. In addition, since the low-frequency signal contains a small proportion of the sound of musical instruments with a larger volume, the sound quality of the sound of musical instruments with a larger volume in the low-frequency signal will be less affected after the low-frequency signal is high-pass filtered using the raised cutoff frequency. Specifically, for each low-frequency signal in the first layer of low-frequency signals, based on the fact that the cutoff frequency corresponding to each low-frequency signal in the layer changes with the increase of the first parameter value of each low-frequency signal, if the low-frequency signals in the layer contain a large proportion of human voices, then the trend of the cutoff frequency corresponding to each low-frequency signal in the layer changing with the increase of the first parameter value of each low-frequency signal remains unchanged, and the cutoff frequency corresponding to each low-frequency signal in the layer is appropriately raised as a whole; similarly, for each low-frequency signal in the second layer of low-frequency signals, based on the fact that the cutoff frequency corresponding to each low-frequency signal in the layer changes with the increase of the first parameter value of each low-frequency signal, if the low-frequency signals in the layer contain a large proportion of human voices, then the trend of the cutoff frequency corresponding to each low-frequency signal in the layer changing with the increase of the first parameter value of each low-frequency signal remains unchanged, and the cutoff frequency corresponding to each low-frequency signal in the layer is also appropriately raised as a whole.

[0088] For each low-frequency signal in the first input signal that contains more important information such as musical instruments and human voices, if the proportion of human voices in the low-frequency signal is small, there is no need to raise the cutoff frequency corresponding to the low-frequency signal to tune the human voice. Instead, it is necessary to determine the cutoff frequency corresponding to the low-frequency signal based on the first parameter value of the low-frequency signal, so as to achieve the purpose of reducing power consumption and reducing damage to the sound quality of the first input signal.

[0089] However, since the first input signal contains more important information such as musical instruments and human voices, the greater the intensity of each low-frequency signal, that is, the greater the first parameter value, the more obvious the tuning demand for the human voice. Therefore, based on the above embodiment, in one embodiment of the present application, the at least two layers of low-frequency signals further include a third layer of low-frequency signals, specifically, Figure 4 、 Figure 5 and Figure 6 As shown, the first parameter value V of each low-frequency signal in the first layer of low-frequency signals ranges from V_min to V2, the first parameter value V of each low-frequency signal in the second layer of low-frequency signals ranges from V2 to V3, and the first parameter value V of each low-frequency signal in the third layer of low-frequency signals ranges from V3 to V_max. Figure 4 、 Figure 5 and Figure 6 It can be seen that the first parameter value of each low-frequency signal in the third layer of low-frequency signals is greater than the first parameter value of each low-frequency signal in the second layer of low-frequency signals, that is, the intensity of each low-frequency signal in the third layer of low-frequency signals is greater than the intensity of each low-frequency signal in the second layer of low-frequency signals, so as to facilitate the subsequent determination of different cutoff frequencies for each low-frequency signal in the third layer of low-frequency signals to meet the tuning requirements of the human voice.

[0090] Optionally, in one embodiment of the present application, the proportion of human voices contained in each low-frequency signal in the third layer of low-frequency signals is small, while the proportion of musical instrument sounds with larger volume is large. In order to reduce the impact on the sound quality of the musical instrument sounds with larger volume contained in each low-frequency signal in the third layer of low-frequency signals, the cutoff frequency corresponding to each low-frequency signal in the third layer of low-frequency signals needs to be lower. Therefore, it can be determined that the cutoff frequency corresponding to each low-frequency signal in the third layer of low-frequency signals is not greater than the cutoff frequency corresponding to each low-frequency signal in the second layer of low-frequency signals.

[0091] Based on the above embodiment, optionally, in one embodiment of the present application, continue as follows Figure 4 and Figure 5 As shown, each low-frequency signal in the third layer of low-frequency signals ( Figure 4 and Figure 5 The cutoff frequency corresponding to each low-frequency signal (where the first parameter value V ranges from V3 to V_max) is the same, which is a lower value fc_min.

[0092] In another embodiment of the present application, the cutoff frequency corresponding to each portion of the low-frequency signal in the third layer of low-frequency signals decreases as the first parameter value of each low-frequency signal increases. This application is not limited to this, and the specific cutoff frequency can be determined based on the tuning requirements of the first input signal.

[0093] Based on the above embodiments, optionally, in one embodiment of the present application, the cutoff frequency corresponding to each low-frequency signal in the third layer of low-frequency signals decreases linearly with the increase of the first parameter value of each low-frequency signal; in another embodiment of the present application, the cutoff frequency corresponding to each low-frequency signal in the third layer of low-frequency signals decreases curve-wise with the increase of the first parameter value of each low-frequency signal. The present application does not impose any limitation on this, and the specific situation depends on the circumstances.

[0094] It should be noted that the present application does not limit the slope of the cutoff frequency corresponding to each low-frequency signal in the third layer of low-frequency signals as the first parameter value of each low-frequency signal increases, and the specific slope can be determined according to the tuning requirements of the first input signal.

[0095] Optionally, in another embodiment of the present application, the human voice contained in each low-frequency signal in the third layer of low-frequency signals accounts for a large proportion, while the sound of musical instruments with a larger volume accounts for a small proportion. At this time, it is necessary to appropriately raise the cutoff frequency corresponding to each low-frequency signal in the third layer of low-frequency signals to make the human voice thinner and crisper; and, since the first parameter value of each low-frequency signal in the third layer of low-frequency signals is large, that is, the intensity is large, the tuning demand of the human voice is more obvious, and only raising the cutoff frequency corresponding to each low-frequency signal in the third layer of low-frequency signals as a whole still cannot meet the tuning demand for the human voice. Therefore, it can be determined that the cutoff frequency corresponding to each low-frequency signal in the third layer of low-frequency signals is greater than the cutoff frequency corresponding to at least part of the low-frequency signals in the second layer of low-frequency signals, that is, greater than the minimum value of the cutoff frequencies corresponding to each low-frequency signal in the second layer of low-frequency signals, and less than the cutoff frequency corresponding to each low-frequency signal in the first layer of low-frequency signals.

[0096] Based on the above embodiment, optionally, in one embodiment of the present application, the cutoff frequency corresponding to each low-frequency signal in the third layer of low-frequency signals increases as the first parameter value of each low-frequency signal increases.

[0097] Optionally, in one embodiment of the present application, continue as Figure 6 As shown, each low-frequency signal in the third layer of low-frequency signals ( Figure 6 The cutoff frequency corresponding to each low-frequency signal in the third layer of low-frequency signals (where the first parameter value V ranges from V3 to V_max) increases linearly with the increase of the first parameter value of each low-frequency signal; in another embodiment of the present application, the cutoff frequency corresponding to each low-frequency signal in the third layer of low-frequency signals increases with the increase of the first parameter value of each low-frequency signal. The present application does not limit this, and the specific situation depends on the specific situation. Moreover, the present application does not limit the slope of the increase of the cutoff frequency corresponding to each low-frequency signal in the third layer of low-frequency signals with the increase of the first parameter value of each low-frequency signal, and the specific situation can be determined according to the tuning requirements of the first input signal.

[0098] It should be noted that, in any of the above embodiments, the cutoff frequency corresponding to each low-frequency signal in the first input signal changes continuously with the increase of the first parameter value of each low-frequency signal, and no discontinuity occurs, that is, the cutoff frequency corresponding to each low-frequency signal in the first layer of low-frequency signals and the cutoff frequency corresponding to each low-frequency signal in the second layer of low-frequency signals change continuously with the increase of the first parameter value of each low-frequency signal, and the cutoff frequency corresponding to each low-frequency signal in the second layer of low-frequency signals and the cutoff frequency corresponding to each low-frequency signal in the third layer of low-frequency signals also change continuously with the increase of the first parameter value of each low-frequency signal.

[0099] It should also be noted that the present application specifies the range of the first parameter value of each low-frequency signal in the first layer of low-frequency signals (i.e. Figure 3 V_min to V1, and Figure 4 、 Figure 5 and Figure 6 V_min to V2), the value range of the first parameter value of each low-frequency signal in the second layer of low-frequency signals ( Figure 4 、 Figure 5 and Figure 6 V2 to V3) and the value range of the first parameter value of each low-frequency signal in the third layer of low-frequency signals ( Figure 4 、 Figure 5 and Figure 6 There is no limitation on the range (V3 to V_max) and the range can be determined according to the conditions of the low-frequency signals in the first input signal.

[0100] It should be further noted that the present application does not limit the value range of the cutoff frequency corresponding to each low-frequency signal in the first layer of low-frequency signals, the value range of the cutoff frequency corresponding to each low-frequency signal in the second layer of low-frequency signals, and the value range of the cutoff frequency corresponding to each low-frequency signal in the third layer of low-frequency signals, and the specific range can be determined according to the tuning requirements of the first input signal.

[0101] Specifically, in one embodiment of the present application, based on the first parameter value of each low-frequency signal in the first input signal and a preset reference value, the first parameter value of each low-frequency signal in the first input signal is converted into a decibel value, the preset reference value is 1, and its order of magnitude and unit are the same as the order of magnitude and unit of the first parameter value; based on the decibel value corresponding to the first parameter value of each low-frequency signal in the first input signal, each low-frequency signal in the first input signal is divided into three layers of low-frequency signals, wherein the decibel value corresponding to the first parameter value of each low-frequency signal in the first layer of low-frequency signals ranges from -30dB to -20dB, including the endpoint value; the second layer of low-frequency signals The decibel value corresponding to the first parameter value of each low-frequency signal in the third layer is in the range of -20dB to -10dB, including the endpoint value; the decibel value corresponding to the first parameter value of each low-frequency signal in the third layer of low-frequency signals is in the range of -10dB to 0dB, including the endpoint value; the cutoff frequency corresponding to each low-frequency signal in the first layer of low-frequency signals is in the range of 300Hz to 500Hz, including the endpoint value; the cutoff frequency corresponding to each low-frequency signal in the second layer of low-frequency signals is in the range of 100Hz to 300Hz, including the endpoint value; the cutoff frequency corresponding to each low-frequency signal in the third layer of low-frequency signals is in the range of 50Hz to 300Hz, including the endpoint value.

[0102] Based on any of the foregoing embodiments, optionally, in one embodiment of the present application, determining, based on the first parameter value of each low-frequency signal in the at least two layers of low-frequency signals, the cutoff frequency corresponding to each low-frequency signal in the at least two layers of low-frequency signals includes:

[0103] Based on the first parameter value of each low-frequency signal in the at least two layers of low-frequency signals, a database is queried to determine a cutoff frequency corresponding to each low-frequency signal in the at least two layers of low-frequency signals.

[0104] It should be noted that, as is known from the foregoing, there are multiple possible correspondences between the cutoff frequencies corresponding to each low-frequency signal in the first input signal and the first parameter values ​​of each low-frequency signal. However, in actual applications, input signals requiring high-pass filtering by the same user generally belong to the same category, and the intensity distributions of the low-frequency signals in the input signals of the same category are substantially the same. Therefore, a predetermined correspondence between the cutoff frequencies corresponding to each low-frequency signal in a second input signal of the same category as the first input signal and the first parameter values ​​of each low-frequency signal can be pre-stored in the database. Based on the first parameter values ​​of each low-frequency signal in the first input signal, the database is queried for the correspondence between the cutoff frequencies corresponding to the low-frequency signals and the first parameter values ​​of the low-frequency signals, and the cutoff frequencies corresponding to each low-frequency signal in the first input signal are determined. Thus, based on the determined cutoff frequencies corresponding to each low-frequency signal in the first input signal, high-pass filtering of each low-frequency signal in the first input signal can produce the same tuning effect as after high-pass filtering of each low-frequency signal in the second input signal.

[0105] Specifically, such as Figure 7 As shown, the method for establishing the database includes:

[0106] S21: dividing each low-frequency signal in the second input signal into at least two layers of low-frequency signals based on a first parameter value of each low-frequency signal in the second input signal, wherein the first parameter value of the low-frequency signal represents the strength of the low-frequency signal;

[0107] It should be noted that the at least two layers of low-frequency signals may include: a first layer of low-frequency signals and a second layer of low-frequency signals, the first parameter value of each low-frequency signal in the second layer of low-frequency signals being greater than the first parameter value of each low-frequency signal in the first layer of low-frequency signals, and may also include: a first layer of low-frequency signals, a second layer of low-frequency signals and a third layer of low-frequency signals, the first parameter value of each low-frequency signal in the second layer of low-frequency signals being greater than the first parameter value of each low-frequency signal in the first layer of low-frequency signals, and the first parameter value of each low-frequency signal in the third layer of low-frequency signals being greater than the first parameter value of each low-frequency signal in the second layer of low-frequency signals. This application does not impose any limitation on this, and the specific circumstances will be determined.

[0108] S22: determining a cutoff frequency corresponding to each low-frequency signal in the at least two layers of low-frequency signals based on a first parameter value of each low-frequency signal in the at least two layers of low-frequency signals;

[0109] S23: performing high-pass filtering processing on each low-frequency signal in the second input signal based on the cut-off frequency corresponding to each low-frequency signal in the at least two layers of low-frequency signals, to obtain an output signal;

[0110] S24: playing the output signal and determining the sound playing quality of the output signal;

[0111] S25: if the sound playing quality of the output signal does not meet the preset requirement, adjusting the cut-off frequency corresponding to each low-frequency signal in the at least two layers of low-frequency signals based on the sound playing quality of the output signal, returning to S22 until the sound playing quality of the output signal meets the preset requirement.

[0112] It should be noted that, in the process of establishing the database, a corresponding relationship between the cut-off frequency corresponding to each low-frequency signal in the at least two layers of low-frequency signals and the first parameter value of each low-frequency signal is preset; the cut-off frequency corresponding to each low-frequency signal in the at least two layers of low-frequency signals is determined based on the first parameter value of each low-frequency signal in the at least two layers of low-frequency signals and the preset corresponding relationship; each low-frequency signal in the second input signal is high-pass filtered according to the determined cut-off frequency corresponding to each low-frequency signal in the at least two layers of low-frequency signals, to obtain an output signal; if the sound playing quality of the output signal does not meet the preset condition, the corresponding relationship between the cut-off frequency corresponding to each low-frequency signal in the at least two layers of low-frequency signals and the first parameter value of each low-frequency signal is adjusted; the cut-off frequency corresponding to each low-frequency signal in the at least two layers of low-frequency signals is re-determined based on the first parameter value of each low-frequency signal in the at least two layers of low-frequency signals and the adjusted corresponding relationship; each low-frequency signal in the second input signal is high-pass filtered again according to the re-determined cut-off frequency corresponding to each low-frequency signal in the at least two layers of low-frequency signals, to obtain an output signal; if the sound playing quality of the output signal still does not meet the preset condition, the corresponding relationship between the cut-off frequency corresponding to each low-frequency signal in the at least two layers of low-frequency signals and the first parameter value of each low-frequency signal is continuously adjusted, the above steps are repeated until the sound playing quality of the output signal meets the preset requirement, the corresponding relationship between the cut-off frequency corresponding to each low-frequency signal in the at least two layers of low-frequency signals and the first parameter value of each low-frequency signal is determined, the database is established, and the determined corresponding relationship between the cut-off frequency corresponding to each low-frequency signal in the at least two layers of low-frequency signals and the first parameter value of each low-frequency signal is stored in the database.

[0113] On the basis of any of the above embodiments, in an embodiment of the present application, as Figure 8As shown, before dividing each low-frequency signal in the first input signal into at least two layers of low-frequency signals based on the first parameter value of each low-frequency signal in the first input signal, the method further includes:

[0114] S4: performing low-pass filtering on the first input signal to obtain low-frequency signals in the first input signal;

[0115] S5: Detect each low-frequency signal in the first input signal to obtain a first parameter value of each low-frequency signal in the first input signal.

[0116] It should be noted that the cutoff frequency for low-pass filtering the first input signal is a preset frequency, the frequency of each low-frequency signal in the first input signal is less than the preset frequency, and each low-frequency signal remains substantially unchanged after low-pass filtering, i.e., each low-frequency signal is attenuated very little or not at all. Optionally, in one embodiment of the present application, the preset frequency is 600 Hz, but this is not limited to this in the present application and will be determined on a case-by-case basis.

[0117] It should also be noted that the frequency of each high-frequency signal in the first input signal is not less than the preset frequency, and each high-frequency signal is attenuated into a first signal after being low-pass filtered. The frequency of each first signal is less than the preset frequency, and its first parameter value is a very small value. Therefore, each first signal can also be detected to obtain the first parameter value of each first signal, and then based on the first parameter value of each first signal, the cutoff frequency corresponding to each first signal is also determined, and the correspondence between the cutoff frequency corresponding to each first signal and its first parameter value is also stored in the database, so as to use the cutoff frequency corresponding to each first signal as the cutoff frequency corresponding to the high-frequency signal before the first signal is attenuated; the cutoff frequency corresponding to each high-frequency signal can also be directly set to the preset cutoff frequency, which is not limited in this application and depends on the specific situation.

[0118] It should be further noted that in the filtering method provided in the embodiment of the present application, after high-pass filtering is performed on each high-frequency signal in the first input signal based on the cutoff frequency corresponding to each first signal or based on the preset cutoff frequency, each high-frequency signal remains basically unchanged, that is, each high-frequency signal is attenuated very little or almost not attenuated.

[0119] In addition, the present invention also provides a filtering device. Figure 9 As shown, the device includes: a controller and a high-pass filter; wherein,

[0120] The controller 10 is configured to divide each low-frequency signal in the first input signal into at least two layers of low-frequency signals based on a first parameter value of each low-frequency signal in the first input signal, wherein the first parameter value of the low-frequency signal represents the strength of the low-frequency signal; and to determine a cutoff frequency corresponding to each low-frequency signal in the at least two layers of low-frequency signals based on the first parameter value of each low-frequency signal in the at least two layers of low-frequency signals, and output the determined cutoff frequency corresponding to each low-frequency signal in the at least two layers of low-frequency signals to the high-pass filter.

[0121] The high-pass filter 20 is configured to perform high-pass filtering on each low-frequency signal in the first input signal based on a cutoff frequency corresponding to each low-frequency signal in the at least two layers of low-frequency signals.

[0122] Specifically, in one embodiment of the present application, the first parameter value of the low-frequency signal includes: at least one of a plurality of amplitude parameter values ​​of the low-frequency signal, and / or at least one of a plurality of energy parameter values ​​of the low-frequency signal, wherein the amplitude parameter value of the low-frequency signal includes: sound pressure value (Pa), voltage value (V), acceleration value (m / s 2 ), etc. The energy parameter values ​​of the low-frequency signal include: sound power value (W), sound intensity value (W / m 2 )wait.

[0123] In the embodiment of the present application, the at least two layers of low-frequency signals include a first layer of low-frequency signals and a second layer of low-frequency signals. Specifically, Figure 3 As shown, Figure 3 A schematic diagram is provided of a changing relationship of the cutoff frequency corresponding to each low-frequency signal in the first input signal as the first parameter value of each low-frequency signal increases, wherein the first parameter value V of each low-frequency signal in the first layer of low-frequency signals ranges from V_min to V1, and the first parameter value V of each low-frequency signal in the second layer of low-frequency signals ranges from V1 to V_max. As can be seen from the figure, the first parameter value of each low-frequency signal in the second layer of low-frequency signals is greater than the first parameter value of each low-frequency signal in the first layer of low-frequency signals, and the cutoff frequency corresponding to each low-frequency signal in the second layer of low-frequency signals is less than the cutoff frequency corresponding to each low-frequency signal in the first layer of low-frequency signals.

[0124] It should be noted that, for different first input signals, although the intensity distribution of the low-frequency signals contained therein is not quite the same, the inventors have found that, in different first input signals, the intensities of the low-frequency signals containing more important information such as musical instruments and human voices are generally larger, and these low-frequency signals with larger intensities have an important impact on the sound quality of the first input signal, while the intensities of the low-frequency signals containing fewer important information such as musical instruments and human voices are generally smaller, and the greater attenuation of these low-frequency signals with smaller intensities will not affect the sound quality of the first input signal. Therefore, in the filtering device provided in the embodiment of the present application, the controller 10 uses the first parameter value of the low-frequency signal to characterize the intensity of the low-frequency signal, thereby dividing the low-frequency signals in the first input signal into at least two layers of low-frequency signals based on the first parameter value of each low-frequency signal in the first input signal, so that different cutoff frequencies can be determined subsequently to perform high-pass filtering on the low-frequency signals of different layers.

[0125] It should also be noted that, since the first input signal contains more musical instruments, human voices and other important information, the intensity of each low-frequency signal is generally larger, and the intensity of each low-frequency signal containing less musical instruments, human voices and other important information is generally smaller, and the first parameter value of each low-frequency signal in the second layer of low-frequency signals is greater than the first parameter value of each low-frequency signal in the first layer of low-frequency signals, indicating that the intensity of each low-frequency signal in the second layer of low-frequency signals is greater than the intensity of each low-frequency signal in the first layer of low-frequency signals, therefore, the low-frequency signals in the first input signal that contain more musical instruments, human voices and other important information will be mainly concentrated in the second layer of low-frequency signals, while the low-frequency signals in the first input signal that contain less musical instruments, human voices and other important information will be mainly concentrated in the second layer of low-frequency signals. It will be mainly concentrated in the first layer of low-frequency signals, and then determine that the cutoff frequency corresponding to each low-frequency signal in the second layer of low-frequency signals is smaller than the cutoff frequency corresponding to each low-frequency signal in the first layer of low-frequency signals, so that when high-pass filtering is performed on each low-frequency signal in the first input signal based on the cutoff frequency corresponding to each low-frequency signal in the at least two layers of low-frequency signals, each low-frequency signal in the first layer of low-frequency signals can be attenuated more, thereby significantly reducing power consumption without affecting the sound quality of the first input signal, while each low-frequency signal in the second layer of low-frequency signals is attenuated less, thereby reducing damage to the sound quality of the first input signal, thereby achieving the purpose of both reducing power consumption and reducing damage to the sound quality of the input signal.

[0126] Based on the above embodiment, optionally, in one embodiment of the present application, continue as follows Figure 3 As shown, each low-frequency signal in the first layer of low-frequency signals ( Figure 3 The cutoff frequency corresponding to each low-frequency signal (where the first parameter value V ranges from V_min to V1) is the same, which is a higher value fc_max.

[0127] In another embodiment of the present application, the cutoff frequencies corresponding to at least some of the low-frequency signals in the first layer of low-frequency signals are different, that is, the cutoff frequencies corresponding to some of the low-frequency signals in the first layer of low-frequency signals may be the same, while the cutoff frequencies corresponding to another part of the low-frequency signals are different, or the cutoff frequencies corresponding to each low-frequency signal may be different. The present application does not impose any limitation on this, and the specific cutoff frequencies may be determined according to the tuning requirements of the first input signal.

[0128] However, if the sound effects of the low-frequency signals in the first layer of low-frequency signals whose first parameter values ​​are greater than a certain threshold also have a significant impact on the sound quality of the first input signal, then using a higher cutoff frequency for high-pass filtering of the low-frequency signals in the first layer of low-frequency signals will cause damage to the sound quality of the low-frequency signals in the first layer of low-frequency signals whose first parameter values ​​are greater than the threshold. On the other hand, using a lower cutoff frequency for high-pass filtering of the low-frequency signals in the first layer of low-frequency signals will not significantly reduce the power consumption of the low-frequency signals in the first layer of low-frequency signals whose first parameter values ​​are less than the threshold. Therefore, , it is necessary to determine the cutoff frequency corresponding to each low-frequency signal in the first layer of low-frequency signals based on the first parameter value of each low-frequency signal in the first layer of low-frequency signals, so that the cutoff frequencies corresponding to at least some of the low-frequency signals in the first layer of low-frequency signals are different, wherein, for each low-frequency signal in the first layer of low-frequency signals whose first parameter value is less than the threshold, a corresponding higher cutoff frequency can be determined, and for each low-frequency signal in the first layer of low-frequency signals whose first parameter value is greater than the threshold, a corresponding different cutoff frequency can be determined, thereby achieving the purpose of reducing power consumption and reducing damage to the sound quality of the first input signal. It should be noted that the present application does not limit the threshold value, and the specific threshold value needs to be determined according to the situation of each low-frequency signal of the first input signal.

[0129] Optionally, in one embodiment of the present application, the influence of the sound effect of each low-frequency signal in the first layer of low-frequency signals on the sound quality of the first input signal increases with the increase of the intensity of each low-frequency signal (that is, the first parameter value of each low-frequency signal). Therefore, the cutoff frequencies corresponding to at least some of the low-frequency signals in the first layer of low-frequency signals may be different:

[0130] The cutoff frequency corresponding to each low-frequency signal in the first layer of low-frequency signals decreases as the first parameter value of each low-frequency signal increases, so as to reduce damage to the sound quality of the first input signal.

[0131] Based on the above embodiment, optionally, in one embodiment of the present application, as Figure 4 As shown, Figure 4A schematic diagram of another changing relationship of the cutoff frequency corresponding to each low-frequency signal in the first input signal as the first parameter value of each low-frequency signal increases is given, wherein the first parameter value V of each low-frequency signal in the first layer of low-frequency signals ranges from V_min to V2, and the cutoff frequency corresponding to each low-frequency signal in the first layer of low-frequency signals decreases linearly as the first parameter value of each low-frequency signal increases. However, the present application does not limit this. In other embodiments of the present application, the cutoff frequency corresponding to each low-frequency signal in the first layer of low-frequency signals can also decrease in a curve as the first parameter value of each low-frequency signal increases, depending on the specific circumstances. It should be noted that the present application does not limit the slope of the decrease in the cutoff frequency corresponding to each low-frequency signal in the first layer of low-frequency signals as the first parameter value of each low-frequency signal increases, and the specific slope can be determined according to the tuning requirements of the first input signal.

[0132] It should be noted that, in the above embodiment, when the sound effects of each low-frequency signal whose first parameter value in the first layer of low-frequency signals is greater than a certain threshold value also have a relatively important impact on the sound quality of the first input signal, it is necessary to appropriately reduce the cutoff frequency corresponding to each low-frequency signal whose first parameter value in the first layer of low-frequency signals is greater than the threshold value to reduce the damage to the sound quality of the first input signal, since the cutoff frequency corresponding to each low-frequency signal in the second layer of low-frequency signals is lower than the cutoff frequency corresponding to each low-frequency signal in the first layer of low-frequency signals, the cutoff frequency corresponding to each low-frequency signal in the second layer of low-frequency signals also needs to be appropriately reduced.

[0133] Since each low-frequency signal in the second layer of low-frequency signals contains a large amount of important information such as musical instruments and human voices, using a higher cutoff frequency to perform high-pass filtering on each low-frequency signal in the second layer of low-frequency signals will cause damage to the sound quality of the second input signal. However, using a lower cutoff frequency to perform high-pass filtering on each low-frequency signal in the second layer of low-frequency signals will not significantly reduce power consumption. In other words, using the same cutoff frequency for each low-frequency signal in the second layer of low-frequency signals cannot achieve both the goals of reducing power consumption and reducing damage to the sound quality of the first input signal. It is necessary to determine the cutoff frequency corresponding to each low-frequency signal in the second layer of low-frequency signals based on the first parameter value of each low-frequency signal in the second layer of low-frequency signals, so that the cutoff frequency corresponding to each low-frequency signal in the second layer of low-frequency signals is different. Specifically, a higher cutoff frequency can be determined for each low-frequency signal in the second layer of low-frequency signals with a smaller first parameter value, and a lower cutoff frequency can be determined for each low-frequency signal in the second layer of low-frequency signals with a larger first parameter value. This achieves the goals of both reducing power consumption and reducing damage to the sound quality of the first input signal.

[0134] Optionally, in one embodiment of the present application, the cutoff frequencies corresponding to the low-frequency signals in the second layer of low-frequency signals may be different:

[0135] The cutoff frequency corresponding to each low-frequency signal in the second layer of low-frequency signals decreases as the first parameter value of each low-frequency signal increases.

[0136] Based on the above embodiment, optionally, in one embodiment of the present application, continue as follows Figure 4 As shown, the first parameter value V of each low-frequency signal in the second layer of low-frequency signals ranges from V2 to V3, and the cutoff frequency corresponding to each low-frequency signal in the second layer of low-frequency signals decreases linearly with the increase of the first parameter value of each low-frequency signal; in another embodiment of the present application, Figure 3 As shown, the first parameter value V of each low-frequency signal in the second layer of low-frequency signals ranges from V1 to V_max, and the cutoff frequency corresponding to each low-frequency signal in the second layer of low-frequency signals decreases as the first parameter value of each low-frequency signal increases. This application does not impose any restrictions on this, and the specific situation depends on the application. It should be noted that this application does not impose any restrictions on the slope of the cutoff frequency corresponding to each low-frequency signal in the second layer of low-frequency signals as the first parameter value of each low-frequency signal increases. The specific slope can be determined according to the tuning requirements of the first input signal.

[0137] Furthermore, for the low-frequency signals in the first input signal that contain more important information such as musical instruments and human voices, the tuning requirements of the human voice also need to be considered. If the human voice accounts for a large proportion in the low-frequency signal, the cutoff frequency corresponding to the low-frequency signal needs to be appropriately raised so that the low-frequency signal can be high-pass filtered using the raised cutoff frequency to make the human voice thinner and crisper. In addition, since the low-frequency signal contains a small proportion of the sound of musical instruments with a larger volume, the sound quality of the sound of musical instruments with a larger volume in the low-frequency signal will be less affected after the low-frequency signal is high-pass filtered using the raised cutoff frequency. Specifically, for each low-frequency signal in the first layer of low-frequency signals, based on the fact that the cutoff frequency corresponding to each low-frequency signal in the layer changes with the increase of the first parameter value of each low-frequency signal, if the low-frequency signals in the layer contain a large proportion of human voices, then the trend of the cutoff frequency corresponding to each low-frequency signal in the layer changing with the increase of the first parameter value of each low-frequency signal remains unchanged, and the cutoff frequency corresponding to each low-frequency signal in the layer is appropriately raised as a whole; similarly, for each low-frequency signal in the second layer of low-frequency signals, based on the fact that the cutoff frequency corresponding to each low-frequency signal in the layer changes with the increase of the first parameter value of each low-frequency signal, if the low-frequency signals in the layer contain a large proportion of human voices, then the trend of the cutoff frequency corresponding to each low-frequency signal in the layer changing with the increase of the first parameter value of each low-frequency signal remains unchanged, and the cutoff frequency corresponding to each low-frequency signal in the layer is also appropriately raised as a whole.

[0138] For each low-frequency signal in the first input signal that contains more important information such as musical instruments and human voices, if the proportion of human voices in the low-frequency signal is small, there is no need to raise the cutoff frequency corresponding to the low-frequency signal to tune the human voice. Instead, it is necessary to determine the cutoff frequency corresponding to the low-frequency signal based on the first parameter value of the low-frequency signal, so as to achieve the purpose of reducing power consumption and reducing damage to the sound quality of the first input signal.

[0139] However, since the first input signal contains more important information such as musical instruments and human voices, the greater the intensity of each low-frequency signal, that is, the greater the first parameter value, the more obvious the tuning demand for the human voice. Therefore, based on the above embodiment, in one embodiment of the present application, the at least two layers of low-frequency signals further include a third layer of low-frequency signals, specifically, Figure 4 、 Figure 5 and Figure 6 As shown, the first parameter value V of each low-frequency signal in the first layer of low-frequency signals ranges from V_min to V2, the first parameter value V of each low-frequency signal in the second layer of low-frequency signals ranges from V2 to V3, and the first parameter value V of each low-frequency signal in the third layer of low-frequency signals ranges from V3 to V_max. Figure 4 、 Figure 5 and Figure 6 It can be seen that the first parameter value of each low-frequency signal in the third layer of low-frequency signals is greater than the first parameter value of each low-frequency signal in the second layer of low-frequency signals, that is, the intensity of each low-frequency signal in the third layer of low-frequency signals is greater than the intensity of each low-frequency signal in the second layer of low-frequency signals, so as to facilitate the subsequent determination of different cutoff frequencies for each low-frequency signal in the third layer of low-frequency signals to meet the tuning requirements of the human voice.

[0140] Optionally, in one embodiment of the present application, the proportion of human voices contained in each low-frequency signal in the third layer of low-frequency signals is small, while the proportion of musical instrument sounds with larger volume is large. In order to reduce the impact on the sound quality of the musical instrument sounds with larger volume contained in each low-frequency signal in the third layer of low-frequency signals, the cutoff frequency corresponding to each low-frequency signal in the third layer of low-frequency signals needs to be lower. Therefore, it can be determined that the cutoff frequency corresponding to each low-frequency signal in the third layer of low-frequency signals is not greater than the cutoff frequency corresponding to each low-frequency signal in the second layer of low-frequency signals.

[0141] Based on the above embodiment, optionally, in one embodiment of the present application, continue as follows Figure 4 and Figure 5 As shown, each low-frequency signal in the third layer of low-frequency signals ( Figure 4 and Figure 5 The cutoff frequency corresponding to each low-frequency signal (where the first parameter value V ranges from V3 to V_max) is the same, which is a lower value fc_min.

[0142] In another embodiment of the present application, the cutoff frequency corresponding to each portion of the low-frequency signal in the third layer of low-frequency signals decreases as the first parameter value of each low-frequency signal increases. This application is not limited to this, and the specific cutoff frequency can be determined based on the tuning requirements of the first input signal.

[0143] Based on the above embodiments, optionally, in one embodiment of the present application, the cutoff frequency corresponding to each low-frequency signal in the third layer of low-frequency signals decreases linearly with the increase of the first parameter value of each low-frequency signal; in another embodiment of the present application, the cutoff frequency corresponding to each low-frequency signal in the third layer of low-frequency signals decreases curve-wise with the increase of the first parameter value of each low-frequency signal. The present application does not impose any limitation on this, and the specific situation depends on the circumstances.

[0144] It should be noted that the present application does not limit the slope of the cutoff frequency corresponding to each low-frequency signal in the third layer of low-frequency signals as the first parameter value of each low-frequency signal increases, and the specific slope can be determined according to the tuning requirements of the first input signal.

[0145] Optionally, in another embodiment of the present application, the human voice contained in each low-frequency signal in the third layer of low-frequency signals accounts for a large proportion, while the sound of musical instruments with a larger volume accounts for a small proportion. At this time, it is necessary to appropriately raise the cutoff frequency corresponding to each low-frequency signal in the third layer of low-frequency signals to make the human voice thinner and crisper; and, since the first parameter value of each low-frequency signal in the third layer of low-frequency signals is large, that is, the intensity is large, the tuning demand of the human voice is more obvious, and only raising the cutoff frequency corresponding to each low-frequency signal in the third layer of low-frequency signals as a whole still cannot meet the tuning demand for the human voice. Therefore, it can be determined that the cutoff frequency corresponding to each low-frequency signal in the third layer of low-frequency signals is greater than the cutoff frequency corresponding to at least part of the low-frequency signals in the second layer of low-frequency signals, that is, greater than the minimum value of the cutoff frequencies corresponding to each low-frequency signal in the second layer of low-frequency signals, and less than the cutoff frequency corresponding to each low-frequency signal in the first layer of low-frequency signals.

[0146] Based on the above embodiment, optionally, in one embodiment of the present application, the cutoff frequency corresponding to each low-frequency signal in the third layer of low-frequency signals increases as the first parameter value of each low-frequency signal increases.

[0147] Optionally, in one embodiment of the present application, continue as Figure 6 As shown, each low-frequency signal in the third layer of low-frequency signals ( Figure 6 The cutoff frequency corresponding to each low-frequency signal in the third layer of low-frequency signals (where the first parameter value V ranges from V3 to V_max) increases linearly with the increase of the first parameter value of each low-frequency signal; in another embodiment of the present application, the cutoff frequency corresponding to each low-frequency signal in the third layer of low-frequency signals increases with the increase of the first parameter value of each low-frequency signal. The present application does not limit this, and the specific situation depends on the specific situation. Moreover, the present application does not limit the slope of the increase of the cutoff frequency corresponding to each low-frequency signal in the third layer of low-frequency signals with the increase of the first parameter value of each low-frequency signal, and the specific situation can be determined according to the tuning requirements of the first input signal.

[0148] Based on the above embodiments, in one embodiment of the present application, Figure 10 As shown, the device further includes: a low-pass filter 30 and a detector 40; wherein,

[0149] The low-pass filter 30 is configured to perform low-pass filtering on the first input signal to obtain low-frequency signals in the first input signal, and output the low-frequency signals in the first input signal to the detector 40;

[0150] The detector 40 is used to detect each low-frequency signal in the first input signal, obtain a first parameter value of each low-frequency signal in the first input signal, and output the first parameter value of each low-frequency signal in the first input signal to the controller 10.

[0151] It should be noted that, in the embodiment of the present application, after any low-frequency signal or any high-frequency signal in the first input signal is received by the filtering device, signal processing will be performed along two branches, wherein, in the first branch, any low-frequency signal or any high-frequency signal is low-pass filtered by the low-pass filter 30. If it is a low-frequency signal, the low-frequency signal remains basically unchanged after being low-pass filtered. The detector 40 detects the low-frequency signal to obtain a first parameter value of the low-frequency signal. The controller 10 determines the cutoff frequency corresponding to the low-frequency signal based on the first parameter value of the low-frequency signal, and outputs it to the high-pass filter 20, so that in the second branch, The high-pass filter 20 in the branch uses the cutoff frequency output by the controller 10 to perform high-pass filtering on the low-frequency signal; if it is a high-frequency signal, the high-frequency signal is attenuated into a first signal after being low-pass filtered, and the detector 40 detects the first signal to obtain a first parameter value of the first signal. The controller 10 determines the cutoff frequency corresponding to the first signal based on the first parameter value of the first signal, and outputs it to the high-pass filter 20 as the cutoff frequency corresponding to the high-frequency signal, so that the high-pass filter 20 in the second branch uses the cutoff frequency output by the controller 10 to perform high-pass filtering on the high-frequency signal.

[0152] It can be understood that after the high-frequency signals in the first input signal are high-pass filtered by the high-pass filter 20, they remain basically unchanged, while after the low-frequency signals in the first input signal are high-pass filtered by the high-pass filter 20, since the cutoff frequencies corresponding to the low-frequency signals are different, the low-frequency signals will be attenuated to different degrees, thereby achieving the purpose of reducing power consumption and reducing damage to the sound effect of the first input signal.

[0153] It should also be noted that in the first branch, the cutoff frequency corresponding to any low-frequency signal or the cutoff frequency corresponding to any high-frequency signal in the first input signal is determined, and in the second branch, the low-frequency signal is high-pass filtered according to the cutoff frequency determined for each low-frequency signal, or the high-frequency signal is high-pass filtered according to the cutoff frequency determined for each high-frequency signal, and both are performed in real time.

[0154] In summary, the filtering method provided in the embodiment of the present application includes: based on the first parameter value of each low-frequency signal in the first input signal, dividing each low-frequency signal in the first input signal into at least two layers of low-frequency signals, the first parameter value of the low-frequency signal representing the strength of the low-frequency signal; based on the first parameter value of each low-frequency signal in the at least two layers of low-frequency signals, determining the cutoff frequency corresponding to each low-frequency signal in the at least two layers of low-frequency signals; based on the cutoff frequency corresponding to each low-frequency signal in the at least two layers of low-frequency signals, performing high-pass filtering on each low-frequency signal in the first input signal; wherein, the at least two layers of low-frequency signals include The invention comprises a first layer of low-frequency signals and a second layer of low-frequency signals, wherein a first parameter value of each low-frequency signal in the second layer of low-frequency signals is greater than a first parameter value of each low-frequency signal in the first layer of low-frequency signals, and a cutoff frequency corresponding to each low-frequency signal in the second layer of low-frequency signals is less than a cutoff frequency corresponding to each low-frequency signal in the first layer of low-frequency signals, so that each low-frequency signal in the first layer of low-frequency signals is attenuated more, thereby significantly reducing power consumption, while each low-frequency signal in the second layer of low-frequency signals is attenuated less, thereby reducing damage to the sound quality of the first input signal, thereby achieving the purpose of reducing power consumption and reducing damage to the sound quality of the input signal.

[0155] The various parts in this manual are described in a combination of parallel and progressive manners. Each part focuses on the differences from other parts, and the same or similar parts between the various parts can be referenced to each other.

[0156] With respect to the above description of the disclosed embodiments, the features described in the various embodiments in this specification may be interchanged or combined with one another to enable those skilled in the art to implement or use the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments shown herein, but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A filtering method, characterized in that: include: dividing each low-frequency signal in the first input signal into at least two layers of low-frequency signals based on a first parameter value of each low-frequency signal in the first input signal, wherein the first parameter value of the low-frequency signal represents the strength of the low-frequency signal; determining a cutoff frequency corresponding to each low-frequency signal in the at least two layers of low-frequency signals based on a first parameter value of each low-frequency signal in the at least two layers of low-frequency signals; performing high-pass filtering on each low-frequency signal in the first input signal based on a cutoff frequency corresponding to each low-frequency signal in the at least two layers of low-frequency signals; Among them, the at least two layers of low-frequency signals include a first layer of low-frequency signals and a second layer of low-frequency signals, the first parameter value of each low-frequency signal in the second layer of low-frequency signals is greater than the first parameter value of each low-frequency signal in the first layer of low-frequency signals, and the cutoff frequency corresponding to each low-frequency signal in the second layer of low-frequency signals is less than the cutoff frequency corresponding to each low-frequency signal in the first layer of low-frequency signals.

2. The filtering method according to claim 1, wherein: The cutoff frequencies corresponding to the low-frequency signals in the first layer of low-frequency signals are the same.

3. The filtering method according to claim 1, wherein: At least some of the low-frequency signals in the first layer of low-frequency signals correspond to different cutoff frequencies.

4. The filtering method according to claim 3, wherein: The cutoff frequency corresponding to each low-frequency signal in the first layer of low-frequency signals decreases as the first parameter value of each low-frequency signal increases.

5. The filtering method according to any one of claims 1 to 4, characterized in that: The cutoff frequencies corresponding to the low-frequency signals in the second layer of low-frequency signals are different.

6. The filtering method according to claim 5, characterized in that: The cutoff frequency corresponding to each low-frequency signal in the second layer of low-frequency signals decreases as the first parameter value of each low-frequency signal increases.

7. The filtering method according to claim 1, wherein: The at least two layers of low-frequency signals further include a third layer of low-frequency signals, and the first parameter value of each low-frequency signal in the third layer of low-frequency signals is greater than the first parameter value of each low-frequency signal in the second layer of low-frequency signals; The cutoff frequency corresponding to each low-frequency signal in the third layer of low-frequency signals is not greater than the cutoff frequency corresponding to each low-frequency signal in the second layer of low-frequency signals.

8. The filtering method according to claim 7, characterized in that: The cutoff frequencies corresponding to the low-frequency signals in the third layer of low-frequency signals are the same, or the cutoff frequencies corresponding to the low-frequency signals in the third layer of low-frequency signals decrease as the first parameter value of each low-frequency signal increases.

9. The filtering method according to claim 1, wherein: The at least two layers of low-frequency signals further include a third layer of low-frequency signals, and the first parameter value of each low-frequency signal in the third layer of low-frequency signals is greater than the first parameter value of each low-frequency signal in the second layer of low-frequency signals; The cutoff frequency corresponding to each low-frequency signal in the third layer of low-frequency signals is greater than the cutoff frequency corresponding to at least part of the low-frequency signals in the second layer of low-frequency signals, and is less than the cutoff frequency corresponding to each low-frequency signal in the first layer of low-frequency signals.

10. The filtering method according to claim 9, characterized in that: The cutoff frequency corresponding to each low-frequency signal in the third layer of low-frequency signals increases as the first parameter value of each low-frequency signal increases.

11. The filtering method according to claim 1, wherein: Determining, based on the first parameter value of each low-frequency signal in the at least two layers of low-frequency signals, a cutoff frequency corresponding to each low-frequency signal in the at least two layers of low-frequency signals includes: Based on the first parameter value of each low-frequency signal in the at least two layers of low-frequency signals, a database is queried to determine a cutoff frequency corresponding to each low-frequency signal in the at least two layers of low-frequency signals.

12. The filtering method according to claim 11, characterized in that: The method for establishing the database includes: dividing each low-frequency signal in the second input signal into at least two layers of low-frequency signals based on a first parameter value of each low-frequency signal in the second input signal, wherein the first parameter value of the low-frequency signal represents the strength of the low-frequency signal; determining a cutoff frequency corresponding to each low-frequency signal in the at least two layers of low-frequency signals based on a first parameter value of each low-frequency signal in the at least two layers of low-frequency signals; performing high-pass filtering on each low-frequency signal in the second input signal based on a cutoff frequency corresponding to each low-frequency signal in the at least two layers of low-frequency signals to obtain an output signal; Playing the output signal and determining the sound playback quality of the output signal; If the sound playback quality of the output signal does not meet the preset requirements, based on the sound playback quality of the output signal, the cutoff frequency corresponding to each low-frequency signal in the at least two layers of low-frequency signals is adjusted until the sound playback quality of the output signal meets the preset requirements.

13. The filtering method according to claim 1, wherein: Before dividing each low-frequency signal in the first input signal into at least two layers of low-frequency signals based on the first parameter value of each low-frequency signal in the first input signal, the method further includes: Performing low-pass filtering on the first input signal to obtain low-frequency signals in the first input signal; Each low-frequency signal in the first input signal is detected to obtain a first parameter value of each low-frequency signal in the first input signal.

14. The filtering method according to claim 1, characterized in that: The first parameter value of the low-frequency signal includes: at least one of a plurality of amplitude parameter values ​​of the low-frequency signal, and / or at least one of a plurality of energy parameter values ​​of the low-frequency signal.

15. A filtering device, characterized in that: include: controller and high-pass filter; where, The controller is configured to divide each low-frequency signal in the first input signal into at least two layers of low-frequency signals based on a first parameter value of each low-frequency signal in the first input signal, wherein the first parameter value of the low-frequency signal represents the strength of the low-frequency signal; and to determine a cutoff frequency corresponding to each low-frequency signal in the at least two layers of low-frequency signals based on the first parameter value of each low-frequency signal in the at least two layers of low-frequency signals, and output the determined cutoff frequency corresponding to each low-frequency signal in the at least two layers of low-frequency signals to the high-pass filter; The high-pass filter is configured to perform high-pass filtering on each low-frequency signal in the first input signal based on a cutoff frequency corresponding to each low-frequency signal in the at least two layers of low-frequency signals; Among them, the at least two layers of low-frequency signals include a first layer of low-frequency signals and a second layer of low-frequency signals, the first parameter value of each low-frequency signal in the second layer of low-frequency signals is greater than the first parameter value of each low-frequency signal in the first layer of low-frequency signals, and the cutoff frequency corresponding to each low-frequency signal in the second layer of low-frequency signals is less than the cutoff frequency corresponding to each low-frequency signal in the first layer of low-frequency signals.

16. The filtering device according to claim 15, characterized in that The device also includes: a low-pass filter and a detector; wherein, The low-pass filter is configured to perform low-pass filtering on the first input signal to obtain low-frequency signals in the first input signal, and output the low-frequency signals in the first input signal to the detector; The detector is used to detect each low-frequency signal in the first input signal, obtain a first parameter value of each low-frequency signal in the first input signal, and output the first parameter value of each low-frequency signal in the first input signal to the controller.

Images