CN115346544A

CN115346544A - Audio signal processing method, apparatus, storage medium, and program product

Info

Publication number: CN115346544A
Application number: CN202110529080.XA
Authority: CN
Inventors: 江建亮
Original assignee: Guangzhou Shiyuan Electronics Thecnology Co Ltd; Guangzhou Shikun Electronic Technology Co Ltd
Current assignee: Guangzhou Shiyuan Electronics Thecnology Co Ltd; Guangzhou Shikun Electronic Technology Co Ltd
Priority date: 2021-05-14
Filing date: 2021-05-14
Publication date: 2022-11-15

Abstract

The present application provides an audio signal processing method, apparatus, storage medium and program product, the method comprising: acquiring an original audio signal; carrying out virtual bass signal processing on the original audio signal to obtain a virtual bass enhanced audio signal; performing frequency division processing on the virtual bass enhanced audio signal to obtain at least two sub-band signals; performing Dynamic Range Control (DRC) processing on the at least two subband signals, respectively, to obtain processed subband signals; and superposing the processed sub-band signals and outputting the superposed sub-band signals to a loudspeaker. The method and the device can solve the problem that the audio definition is reduced after the audio virtual bass is processed.

Description

Audio signal processing method, apparatus, storage medium, and program product

Technical Field

The present application relates to signal processing technologies, and in particular, to an audio signal processing method, apparatus, storage medium, and program product.

Background

With the increasing miniaturization of electronic devices and electronic components, the common output devices of electro-acoustic systems, such as speakers, are also becoming smaller, which makes multimedia devices more portable, aesthetically pleasing, and power efficient. However, from the perspective of high fidelity of an electroacoustic system, a small volume of a loudspeaker is a great disadvantage, that is, when the volume of the loudspeaker and the loudspeaker box becomes small, the bass cut-off frequency of the loudspeaker is raised, that is, the loudspeaker with a small volume cannot effectively reproduce low-frequency sound below the cut-off frequency.

To address this problem, a common approach is to use a virtual bass technique, which is based on the "missing fundamental phenomenon" in psychoacoustics, and uses a harmonic sequence of fundamental frequencies within the active frequency band of the speaker to restore the tone and timbre of the fundamental frequency, so that the listener can generate an auditory perception similar to the fundamental tone. At present, a common virtual bass enhancement technology can convert a time domain signal into a frequency domain by using a time-frequency conversion technology, generate a harmonic corresponding to a fundamental frequency in the frequency domain, and convert the harmonic into a time domain. To solve this problem, in multimedia playback scenes such as TVs, which require high real-time performance, a nonlinear device (NLD) algorithm is generally used to nonlinearly process a low-frequency signal and generate harmonics. However, this approach introduces intermodulation distortion to the audio signal with rich harmonic components, and in addition, the low frequency harmonics may psychoacoustically mask the low amplitude high frequency signal, so that the high frequency components of the auditory perception are reduced, thereby resulting in the reduction of the audio intelligibility of the auditory perception.

Disclosure of Invention

An audio signal processing method, apparatus, storage medium, and program product are provided to improve the problem of audio clarity degradation due to virtual bass processing.

In a first aspect, the present application provides an audio signal processing method, including:

acquiring an original audio signal;

carrying out virtual bass signal processing on the original audio signal to obtain a virtual bass enhanced audio signal;

performing frequency division processing on the virtual bass enhanced audio signal to obtain at least two sub-band signals;

performing DRC processing on the at least two sub-band signals respectively to obtain processed sub-band signals;

and superposing the processed sub-band signals and outputting the superposed sub-band signals to a loudspeaker.

In the scheme, the amplitude of the subband signals can be adjusted by carrying out DRC processing on each subband signal, and the dynamic characteristic of the subband signals and the relative energy between the subbands can be adjusted because the energy and the amplitude of the subband signals are related, so that the problem of audio definition reduction caused by virtual bass processing can be solved. In addition, through adopting DRC technology, the probability of distortion of the virtual bass algorithm can be reduced while the advantages of the virtual bass technology are exerted to the maximum extent, the unnatural sound after the virtual bass is enhanced under certain conditions is avoided, particularly when the cut-off frequency of the loudspeaker is very high, the double combination of the virtual bass and the audio dynamic range control can effectively enlarge the listening and sensing sound range of the loudspeaker, and the perceived unnatural distortion is weakened based on the psychoacoustic masking effect.

Optionally, the frequency dividing processing the virtual bass enhanced audio signal to obtain at least two subband signals includes:

determining a cut-off frequency for virtual bass in the virtual bass-enhanced audio signal in dependence on the cut-off frequency of the loudspeaker;

determining a first frequency dividing point according to the cut-off frequency of the virtual bass;

and according to the first frequency dividing point, carrying out frequency division processing on the audio signal enhanced by the virtual bass to obtain at least two sub-band signals.

In the scheme, the cut-off frequency of the virtual bass in the audio signal enhanced by the virtual bass is determined according to the cut-off frequency of the loudspeaker, and after the first frequency dividing point is determined, the frequency division processing can be performed on the audio signal enhanced by the virtual bass according to the first frequency dividing point, so that at least two sub-band signals are obtained. The cut-off frequency corresponding to the virtual bass is considered, so that the virtual bass signal is reserved, the dynamic characteristic of the audio signal is adjusted, the definition of the audio signal can be improved, and the tone of the audio signal is improved. In addition, because the cut-off frequency corresponding to the virtual bass is considered, the subband signal containing the main fundamental frequency harmonic and the high-frequency subband signal can be obtained, and the dynamic characteristics of the subband signal and the high-frequency subband signal are respectively adjusted, so that the definition of the audio signal is improved.

Optionally, the number of the subband signals is at least three;

according to the first frequency dividing point, frequency division processing is carried out on the audio signals enhanced by the virtual bass to obtain at least three subband signals, and the method comprises the following steps:

determining the number of frequency dividing points of other frequency dividing points except the first frequency dividing point and corresponding frequency dividing frequency according to system computing resources;

and performing frequency division processing on the audio signal enhanced by the virtual bass according to the first frequency division point, the number of the frequency division points and the frequency division frequency to obtain at least three sub-band signals.

According to the cutoff frequency of the loudspeaker, the cutoff frequency of the virtual bass in the audio signal enhanced by the virtual bass is determined, and after the first frequency dividing point is determined based on the cutoff frequency of the virtual bass in the audio signal enhanced by the virtual bass, system computing resources can be further considered, the number of frequency dividing points of other frequency dividing points except the first frequency dividing point and the corresponding frequency dividing frequency are determined according to the system computing resources, so that the audio signal enhanced by the virtual bass is subjected to frequency dividing processing according to the first frequency dividing point, the number of frequency dividing points and the corresponding frequency dividing frequency, and at least three subband signals are obtained. Because the cut-off frequency corresponding to the virtual bass is considered, the subband signal containing the main fundamental frequency harmonic and the high-frequency subband signal can be obtained, and the dynamic characteristics of the subband signal and the high-frequency subband signal are respectively adjusted, so that the definition of the audio signal is improved.

Optionally, the frequency division processing is performed on the audio signal enhanced by the virtual bass according to the first frequency division point, the number of the frequency division points, and the frequency division frequency to obtain at least three subband signals, including:

and performing band division filtering processing on the virtual bass enhanced audio signal by adopting a linear phase frequency division filter group according to the first frequency division point, the number of the frequency division points and the frequency division frequency to obtain at least three sub-band signals.

In the scheme, the linear phase frequency division filter group is adopted to carry out frequency division filtering processing on the virtual bass enhanced audio signal, so that the distortion of frequency response of each sub-band signal at a frequency division point can be reduced.

Optionally, the performing virtual bass signal processing on the original audio signal to obtain a virtual bass enhanced audio signal includes:

performing band-division filtering processing on the original audio signal through a high-pass filter and a low-pass filter respectively to obtain a high-frequency signal and a low-frequency signal, wherein the cut-off frequency of the high-pass filter is not greater than the cut-off frequency of the loudspeaker, and the cut-off frequency of the low-pass filter is not less than the cut-off frequency of the loudspeaker;

carrying out virtual bass signal processing on the low-frequency signal to obtain a virtual bass signal;

carrying out time delay processing on the high-frequency signal to obtain a time-delayed high-frequency signal;

and synthesizing the delayed high-frequency signal and the virtual bass signal to obtain the audio signal enhanced by the virtual bass.

Optionally, the performing DRC processing on the at least two subband signals respectively to obtain processed subband signals includes:

and performing dynamic range compression processing in DRC on a first subband signal in the at least two subband signals, and performing dynamic range expansion processing in DRC on other subband signals except the first subband signal in the at least two subband signals to obtain the processed subband signal.

Through the processing in the scheme, the definition of the audio signal can be further improved.

In a second aspect, the present application provides an audio signal processing apparatus comprising:

an acquisition unit configured to acquire an original audio signal;

the processing unit is used for carrying out virtual bass signal processing on the original audio signal to obtain a virtual bass enhanced audio signal;

the processing unit is further configured to perform frequency division processing on the virtual bass enhanced audio signal to obtain at least two subband signals;

the processing unit is further configured to perform DRC processing on the at least two subband signals, respectively, to obtain processed subband signals;

and the output unit is used for superposing the processed sub-band signals and outputting the superposed sub-band signals to a loudspeaker.

Optionally, the processing unit is specifically configured to:

Optionally, the number of the subband signals is at least three;

the processing unit is specifically configured to:

Optionally, the processing unit is specifically configured to:

and performing frequency-division filtering processing on the virtual bass enhanced audio signal by adopting a linear phase frequency-division filter group according to the first frequency-division point, the number of the frequency-division points and the frequency-division frequency to obtain at least three sub-band signals.

Optionally, the processing unit is specifically configured to:

and performing dynamic range compression processing in DRC on a first subband signal of the at least two subband signals, and performing dynamic range expansion processing in DRC on other subband signals except the first subband signal of the at least two subband signals to obtain the processed subband signal.

In a third aspect, the present application provides a computer-readable storage medium, in which computer-executable instructions are stored, and when a processor executes the computer-executable instructions, the audio signal processing method according to the first aspect is implemented.

In a fourth aspect, the present application provides a computer program product comprising a computer program which, when executed by a processor, implements the audio signal processing method of the first aspect described above.

According to the audio signal processing method, the audio signal processing device, the storage medium and the program product, after the frequency division processing is carried out on the audio signal enhanced by the virtual bass, DRC processing is carried out on at least two obtained sub-band signals, so that the processed sub-band signals are superposed to obtain a final audio signal, and the finally obtained audio signal is fed back to the loudspeaker. Since the sub-band signal is subjected to DRC processing, the amplitude of the sub-band signal can be adjusted, so that the problem of degradation in audio clarity due to virtual bass distortion can be improved.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and together with the description, serve to explain the principles of the application.

Fig. 1 is a schematic flowchart of an audio signal processing method according to an embodiment of the present application;

FIG. 2 is a schematic flow chart of determining a virtual bass enhanced audio signal according to an embodiment of the present application;

FIG. 3 is a schematic diagram of an audio input to output magnitude mapping for DRC processing of a first subband signal;

FIG. 4 is a schematic representation of the magnitude mapping of audio input to output for DRC processing of other subband signals;

fig. 5 is a schematic flowchart of another audio signal processing method according to an embodiment of the present application;

fig. 6 is a schematic flowchart of another audio signal processing method according to an embodiment of the present application;

FIG. 7 is a schematic diagram of the processing of a virtual bass enhanced audio signal;

fig. 8 is a schematic structural diagram of an audio signal processing apparatus according to an embodiment of the present application;

fig. 9 is a schematic structural diagram of an electronic device according to an embodiment of the present application.

With the above figures, there are shown specific embodiments of the present application, which will be described in more detail below. The drawings and written description are not intended to limit the scope of the inventive concepts in any manner, but rather to illustrate the concepts of the application by those skilled in the art with reference to specific embodiments.

Detailed Description

Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present application, as detailed in the appended claims.

Currently, there are two main types of directions for improving the bass reproduction effect of a loudspeaker: one is that the gain of low frequency is directly increased by adopting the form of equalizer (adjusting EQ), and this kind of method can improve the playback effect of low sound to a certain extent, but the gain amplitude is difficult to control, which is easy to cause irreversible damage to the loudspeaker and can reduce the service life of the loudspeaker; and secondly, virtual bass enhancement processing is carried out on the audio signals by utilizing the principle of fundamental frequency missing in psychoacoustics, and the method can effectively improve the bass perception of a listener by replaying the harmonic components of the synthesized bass fundamental frequency while ensuring the normal work of the small loudspeaker.

The first method is to convert a time domain signal into a frequency domain by using a time-frequency conversion technology, generate a harmonic corresponding to a fundamental frequency in the frequency domain, and convert the harmonic into a time domain. To solve this problem, a second type of technique, that is, a nonlinear device (NLD) algorithm, can be used to perform nonlinear processing on the low-frequency signal to generate harmonics. NLD has simple structure and good real-time performance, but can introduce intermodulation distortion to audio signals with rich harmonic components, so that the audio definition is reduced.

Based on the above problem, the embodiments of the present application provide an audio signal processing method, which considers that the perceptual sharpness of an audio signal is related to the magnitude of the relative energy between the frequency bands of the audio, and appropriately increases the amplitude of the high-frequency signal in the virtual bass or appropriately decreases the amplitude of the low-frequency signal in the virtual bass, so as to improve the masking of the generated fundamental frequency harmonic on the medium-frequency and high-frequency signals. Therefore, after the virtual bass enhancement processing is performed on the original audio signal, the frequency division processing may be performed on the obtained virtual bass enhanced audio signal, and the at least two sub-band audio signals after the frequency division processing are further processed by Dynamic Range Control (DRC) to adjust the amplitude (energy and amplitude are directly related) of each sub-band signal, and by using the psycho-acoustic masking effect, the problem of audio clarity degradation due to virtual bass distortion is improved.

It should be noted that the present specification is not intended to exhaust all alternative embodiments for the sake of brevity, and it should be understood by those skilled in the art after reading the present specification that any combination of features may constitute an alternative embodiment as long as the features are not mutually inconsistent.

For example, one technical feature a is described in one embodiment of example 1, and another technical feature b is described in another embodiment of example 1. Since the above two technical features are not mutually inconsistent, after reading the present specification, one skilled in the art should be able to conceive that an embodiment having both of these features is also an alternative embodiment, namely a and b.

The features described in the different embodiments, which are not mutually inconsistent, may also be arbitrarily combined to form alternative embodiments.

For example, the technical feature c is described in example 1. This technical feature is not described in examples 2 and 3 for the sake of controlling the space of the specification of the present application. However, it should be understood by those skilled in the art after reading the present specification that the audio signal processing methods provided in embodiments 2 and 3 may also include this technical feature.

Examples 1,2 and 3 will be described in detail below.

Example 1

The embodiment of the application discloses an audio signal processing method, which is applied to electronic equipment with an audio play-out function, such as a small loudspeaker, or the electronic equipment comprises the small loudspeaker. The audio signal processing method provided by the embodiment of the present application will be described in detail below with reference to fig. 1.

Fig. 1 is a flowchart of an audio signal processing method according to an embodiment of the present application. The method comprises the following steps:

step 101: an original audio signal is acquired.

Step 102: and carrying out virtual bass signal processing on the original audio signal to obtain a virtual bass enhanced audio signal.

After the electronic equipment acquires the original audio signal to be played, the low-frequency signal in the original audio signal is subjected to virtual bass signal processing, so that the bass effect of auditory perception when the electronic equipment plays the audio signal is improved.

Fig. 2 is a schematic flowchart of a process for determining a virtual bass enhanced audio signal according to an embodiment of the present application, and as shown in fig. 2, when performing virtual bass signal processing on an original audio signal to obtain a virtual bass enhanced audio signal, the process may include the following steps:

step 1021: and performing band-division filtering processing on the original audio signal through a high-pass filter and a low-pass filter respectively to obtain a high-frequency signal and a low-frequency signal.

The cut-off frequency of the high-pass filter for acquiring the high-frequency signal is not greater than the cut-off frequency of the loudspeaker, and the cut-off frequency of the low-pass filter for acquiring the low-frequency signal is not less than the cut-off frequency of the loudspeaker.

Step 1022: and carrying out virtual bass signal processing on the low-frequency signal to obtain a virtual bass signal.

Step 1023: and carrying out time delay processing on the high-frequency signal to obtain a time-delayed high-frequency signal.

Step 1024: and synthesizing the delayed high-frequency signal and the virtual bass signal to obtain the audio signal with enhanced virtual bass.

Specifically, the original audio signal is first subjected to a high-pass filter and a low-pass filter for frequency-division filtering processing, so as to obtain a high-frequency signal and a low-frequency signal. Further, a harmonic generation algorithm may be applied to the obtained low-frequency signal to generate each higher harmonic to which the speaker can respond, thereby obtaining a virtual bass signal. And then the virtual bass signal and the delayed high-frequency signal are superposed to generate a finally enhanced virtual bass signal, namely a virtual bass enhanced audio signal.

Step 103: and carrying out frequency division processing on the audio signal with the enhanced virtual bass to obtain at least two sub-band signals.

The more the number of the sub-band signals after frequency division is, the more the details of high-frequency signal processing can be enriched.

Illustratively, a subband filter bank is provided in the electronic device, the subband filter bank being composed of N bandpass filters. The cut-off frequency of the band-pass filter is set according to the cut-off frequency f0 of an audio device (such as a loudspeaker) in the electronic device. The electronic device combines the virtual bass enhanced audio signal X with the subband filter bank _in (N) performing subband filtering processing to obtain N subband signals Xb _i (n) wherein Xb _i (N) denotes the ith subband signal, where i =1,2,3.

Step 104: and performing DRC processing on at least two sub-band signals respectively to obtain processed sub-band signals.

Wherein, the DRC technique is adopted to map the dynamic range of the input audio amplitude into a preset dynamic range, thereby controlling the amplitude of the audio signal.

In this step, since the perceptual sharpness of the audio signal is related to the magnitude of the relative energy between the frequency bands of the audio, and appropriately increasing the amplitude of the high frequency signal or appropriately decreasing the amplitude of the virtual bass low frequency signal can improve the masking of the generated fundamental frequency harmonic to the mid high frequency signal. Therefore, the electronic device can perform DRC processing on the subband signals and adjust the amplitude of the subband signals to change the relative energy amount between the subband signals and the dynamic characteristics of the subband signals, thereby improving the overall intelligibility of the audio signal.

In one possible implementation, when performing DRC processing on at least two subband signals, a first subband signal of the at least two subband signals may be subjected to dynamic range compression processing in DRC, and other subband signals except the first subband signal of the at least two subband signals may be subjected to dynamic range expansion processing in DRC, so as to obtain processed subband signals.

In order to improve the definition better, the amplitude of the first subband signal may be compressed to reduce the amplitude of the first subband signal. In addition, the amplitudes of the other high-frequency subband signals except the first subband signal may be expanded to increase the amplitudes of the other high-frequency subband signals.

FIG. 3 is a schematic diagram showing the mapping relationship between audio input and audio output of DRC processing for a first subband signal, as shown in FIG. 3, for an input signal with an amplitude smaller than-30 dB, the input signal is directly output according to the original amplitude, but for an input signal with an amplitude of-30 dB to 0dB, the amplitude of the output signal can be linearly mapped to-30 dB to-5 dB, where the linear mapping is processed by: assuming that the input signal amplitude is x dB, the output signal amplitude is: y = -30+ (x- (-30)) (-5- (-30))/(0- (-30)) dB; and for input signals higher than-5 dB, the amplitude of the output signal is controlled to be-5 dB.

FIG. 4 is a schematic diagram of the magnitude mapping relationship between the audio input and output of DRC processing of other subband signals, as shown in FIG. 4, for an input signal with an input magnitude less than-50 dB, the input signal is output after the magnitude is linearly increased by 30 dB; for-50-0 dB input signals, the amplitude of the output signals of the linear mapping is-20-0 dB, and the processing mode of the linear mapping is as follows: assuming that the input signal amplitude is x dB, the output signal amplitude is: y = -20+ (x- (-50)) × (0- (-20))/(0- (-50)) dB; for input signals above 0dB, the amplitude of the output signal can be set to 0dB.

It should be understood that the values in fig. 3 and fig. 4 are only examples, and in practical applications, other mapping relationships may be used to control the dynamic range of the first subband signal and other subbands. In practical applications, the mapping relationship between the input and the output of different subband signals needs to be adjusted according to actual situations. The DRC processing parameters for the two sub-bands are not specifically limited here.

Step 105: and superposing the processed sub-band signals and outputting the superposed sub-band signals to a loudspeaker.

In this step, DRC processing is performed on the subband signals to obtain processed subband signals, and then the processed subband signals are subjected to time domain superposition to obtain final audio signals, and the audio signals are input to a speaker to be output.

According to the audio signal processing method provided by the embodiment of the application, after the frequency division processing is performed on the audio signal enhanced by the virtual bass, the DRC processing is performed on at least two obtained sub-band signals, the sub-band signals subjected to the DRC processing are overlapped to obtain a final audio signal, and the finally obtained audio signal is transmitted to the loudspeaker. Due to DRC processing of each sub-band signal, the amplitude of the sub-band signal can be adjusted, and due to the fact that the energy and the amplitude of the sub-band signal are related, the dynamic characteristic of the sub-band signal and the relative energy between sub-bands can be adjusted, and therefore the problem that the audio definition is reduced due to virtual bass distortion is solved. In addition, by changing the relative energy between the middle-high frequency sub-band and the low frequency sub-band (sub-band containing synthesized harmonic components), the double combination of virtual bass and treble dynamic range compression can effectively enlarge the listening range of the loudspeaker, and can also utilize psycho-acoustic masking effects to reduce or even eliminate audible distortion.

Example 2

Fig. 5 is a schematic flowchart of another audio signal processing method according to an embodiment of the present application, and the embodiment explains a process of performing frequency division processing on a virtual bass enhanced audio signal in step 103 to obtain two subband signals on the basis of the embodiment shown in fig. 1. As shown in fig. 5, this embodiment includes:

step 501: an original audio signal is obtained.

Step 502: and carrying out virtual bass signal processing on the original audio signal to obtain a virtual bass enhanced audio signal.

Steps 501 to 502 are similar to steps 101 to 102, and are not described herein again.

Step 503: the cut-off frequency of the virtual bass sounds in the virtual bass enhanced audio signal is determined in dependence of the cut-off frequency of the loudspeaker.

In this step, the cut-off frequency of the loudspeaker is related to the volume of the loudspeaker, wherein the smaller the volume, the higher the cut-off frequency of the loudspeaker.

Specifically, the cutoff frequency of the speaker may be increased by a first preset threshold value, so as to obtain the cutoff frequency f0 of the virtual bass in the virtual bass-enhanced audio signal.

Step 504: and determining a first frequency dividing point according to the cut-off frequency of the virtual bass.

Wherein, since the first 3 high frequency harmonics (2, 3,4 harmonics) generated by the virtual bass algorithm have the largest contribution to the perception of the synthesized virtual bass, in order to maintain the bass listening sensation enhancing effect of the virtual bass, in practical applications, the first frequency dividing point f1 may be set to be greater than or equal to 4f0.

In this embodiment, the cutoff frequency of the virtual bass may be determined first by the cutoff frequency of the speaker, and then the first frequency dividing point may be determined according to the cutoff frequency of the virtual bass.

Step 505: and according to the first frequency dividing point, carrying out frequency division processing on the audio signal enhanced by the virtual bass to obtain two sub-band signals.

In this step, after the first frequency division point is determined, two linear phase band-pass filters are generated according to the first frequency division point to perform frequency division filtering processing on the virtual bass enhanced audio signal, so as to obtain two subband signals. And the frequency range of the first band-pass filter is 20 Hz-f 1, the frequency range of the second band-pass filter is f 1-fs/2, wherein fs is the sampling frequency of the audio signal.

For example, assuming that the first frequency dividing point is 300hz, and the frequency range of the audio signal for enhancing virtual bass is 20hz to 20Khz, two sub-band signals are obtained after frequency division processing is performed on the audio signal for enhancing virtual bass according to the first frequency dividing point, wherein the frequency range of the first sub-band signal is 20hz to 300hz, and the frequency range of the second sub-band signal is 300hz to 20Khz.

Step 506: and performing DRC processing on the two sub-band signals respectively to obtain processed sub-band signals.

In this step, after the frequency division processing is performed on the audio signal enhanced by the virtual bass to obtain two subband signals, DRC processing is performed on the two subband signals, respectively.

For example, the dynamic range compression processing in DRC may be applied to the first subband signal, which may specifically be performed in the manner shown in fig. 3 and will not be described here again. The dynamic range expansion processing in DRC can be performed on the second subband signal, which can be specifically performed in the manner shown in fig. 4 and is not described herein again. It should be understood that in practical applications, the DRC processing parameters for the two sub-band signals may be adjusted as needed. The DRC processing parameters for the two sub-bands are not specifically limited here.

Step 507: and superposing the processed sub-band signals and outputting the superposed sub-band signals to a loudspeaker.

In this step, the two DRC-processed subband signals may be superimposed in the time domain, for example, the amplitudes of the two DRC-processed subband signals may be added. And the superposed signals are transmitted to a loudspeaker for output, and the definition of the audio signals can be improved due to the fact that the dynamic characteristics and the relative energy of the sub-band containing the harmonic signals generated by the virtual bass algorithm and the middle and high frequency sub-bands are changed.

In this embodiment, after determining the cut-off frequency of the virtual bass in the audio signal enhanced by the virtual bass according to the cut-off frequency of the speaker, based on the cut-off frequency of the virtual bass, a first frequency dividing point may be determined, and then according to the first frequency dividing point, the audio signal enhanced by the virtual bass is subjected to frequency division processing, so as to obtain two sub-band signals. Due to the fact that the cut-off frequency corresponding to the virtual bass is considered, on one hand, the bass listening effect of the virtual bass can be kept to the maximum degree, on the other hand, the dynamic range of the medium-high frequency audio signal is improved, and finally the integral definition of the audio signal is improved.

Example 3

Fig. 6 is a flowchart of another audio signal processing method according to an embodiment of the present application, which illustrates a process of performing frequency division processing on a virtual bass-enhanced audio signal in step 103 to obtain at least three subband signals based on the embodiment shown in fig. 1. As shown in fig. 6, this embodiment includes:

step 601: an original audio signal is obtained.

Step 602: and carrying out virtual bass signal processing on the original audio signal to obtain a virtual bass enhanced audio signal.

Step 603: the cut-off frequency of the virtual bass sounds in the virtual bass enhanced audio signal is determined in dependence of the cut-off frequency of the loudspeaker.

Step 604: and determining a first frequency dividing point according to the cut-off frequency of the virtual bass.

Steps 601-604 are similar to steps 501-504 and are not described here.

Step 605: and determining the number of frequency dividing points and the frequency dividing frequency of other frequency dividing points except the first frequency dividing point according to the system computing resources.

In this step, the system computing resource may be, for example, computing power of a Central Processing Unit (CPU) of the electronic device, occupation of Digital Signal Processing (DSP) resources, occupancy of memory, or the like, and the number of frequency divisions of the frequency division points other than the first frequency division point is related to the situation of the system computing resource. The electronic device may determine the number of frequency divisions of the frequency division point corresponding to different situations of each system calculation resource and the frequency division frequency corresponding to each frequency division point according to a preset correspondence.

For example, if the computing power of the CPU of the electronic device is strong, 3 additional frequency dividing points other than the first frequency dividing point may be set, which are 2Khz, 6Khz and 10Khz, respectively, if the computing power of the CPU of the electronic device is general, 2 additional frequency dividing points other than the first frequency dividing point may be set, which are 2Khz and 6Khz, respectively, if the computing power of the CPU of the electronic device is weak, only 1 frequency dividing point other than the first frequency dividing point may be set, and a specific value of the frequency dividing point may be 2Khz.

When the system computing resource is the occupation of DSP resource or the occupancy of memory, the setting manner of the number of frequency dividing points and the corresponding frequency dividing frequency is similar to that when the system computing resource is the computing power of CPU, and is not described herein again.

Step 606: and carrying out frequency division processing on the audio signal enhanced by the virtual bass according to the first frequency division point, the number of the frequency division points and the corresponding frequency division frequency to obtain at least three sub-band signals.

In this step, if the determined first frequency division point and the number of frequency division points determined according to the system computing resources are N, the first frequency division point is f1, and the subsequent frequency division points are fn, where N is 2,3, \8230 \ 8230and N, a frequency division filter bank may be generated according to the N frequency division points, where the frequency division filter bank may be composed of N +1 subband filters.

In a possible implementation manner, the above-mentioned frequency division filter bank may be implemented by using a linear phase frequency division filter bank, so that the electronic device may perform frequency division filtering processing on the virtual bass-enhanced audio signal by using the linear phase frequency division filter bank according to the determined first frequency division point f1 and the subsequent frequency division point fn, thereby obtaining N +1 subband signals.

Because the linear phase frequency division filter group is adopted to carry out frequency division filtering processing on the virtual bass enhanced audio signal, the distortion of the frequency response of each subband signal at a frequency division point can be reduced.

Step 607: and performing DRC processing on at least three sub-band signals respectively to obtain processed sub-band signals.

Fig. 7 is a schematic diagram illustrating a principle of processing a virtual bass-enhanced audio signal, and as shown in fig. 7, the virtual bass-enhanced audio signal is input to a linear phase frequency division filter bank for frequency division filtering processing according to a multiband frequency division point, so as to obtain an N +1 subband signal, where N is a positive integer. The DRC processing is performed on the N +1 subband signals, for example, the dynamic range compression processing in DRC can be performed on the subband signals 1, which can be specifically performed in the manner shown in fig. 3, and details are not described here. The dynamic range expansion processing in DRC can be adopted for the subband signal 2-subband signal N +1, which can be specifically performed in the manner shown in fig. 4 and will not be described herein again. It should be appreciated that in practical applications, the DRC processing parameters for the N +1 subband signals may be adjusted as desired. The DRC processing parameters for the two sub-bands are not specifically limited here.

Step 608: and superposing the processed sub-band signals and outputting the superposed sub-band signals to a loudspeaker.

In this step, as shown in fig. 7, the N +1 sub-band signals subjected to DRC processing may be superimposed, and the superimposed audio output signal may be transmitted to a speaker for playing.

For example, assuming that the first frequency dividing point is 300hz, the second frequency dividing point and the third frequency dividing point are 2Khz and 6Khz, respectively, and the frequency range of the virtual bass enhanced audio signal is 20hz to 20Khz, the frequency dividing processing is performed on the virtual bass enhanced audio signal according to the first frequency dividing point, the second frequency dividing point and the third frequency dividing point, so as to obtain four subband signals, which are a first subband signal of 20hz to 300hz, a second subband signal of 300hz to 2Khz, a third subband signal of 2Khz to 6Khz, and a fourth subband signal of 6Khz to 20Khz, respectively. Since the first subband signal having a lower frequency is mainly the virtual bass processing harmonic dominant band, and the second, third and fourth subband signals having a higher frequency have a greater influence on the intelligibility of the audio signal. Thus, the electronic device will perform DRC processing on the first subband signal with reference to the DRC input-to-output mapping illustrated in fig. 3, and the remaining subband signals with reference to the DRC input-to-output mapping illustrated in fig. 4. And overlapping the sub-band signals subjected to DRC processing, and outputting the final overlapped signals through a loudspeaker. Here, no specific limitation is imposed on the DRC input/output mapping relationships of each subband signal, and in practical applications, these mapping relationships may be adjusted more practically.

In this embodiment, after determining the cut-off frequency of the virtual bass in the virtual bass enhanced audio signal according to the cut-off frequency of the speaker, and after determining the first frequency dividing point based on the cut-off frequency of the virtual bass in the virtual bass enhanced audio signal, system computing resources may be further considered, and the number of frequency dividing points and the frequency of the frequency dividing points of other frequency dividing points are determined according to the system computing resources, so that frequency division processing is performed on the virtual bass enhanced audio signal according to the final number of frequency dividing points and frequency of the frequency dividing points, so as to obtain at least three subband signals. Because the cut-off frequency corresponding to the virtual bass is considered, the bass listening effect of the virtual bass can be reserved, and on the other hand, the integral definition of the audio signal is finally improved by improving the dynamic range of the medium-high frequency audio signal.

Fig. 8 is a schematic structural diagram of an audio signal processing apparatus 80 according to an embodiment of the present application, and for example, referring to fig. 8, the audio signal processing apparatus 80 may include:

an acquisition unit 11 configured to acquire an original audio signal;

a processing unit 12, configured to perform virtual bass signal processing on the original audio signal to obtain a virtual bass-enhanced audio signal;

the processing unit 12 is further configured to perform frequency division processing on the virtual bass enhanced audio signal to obtain at least two subband signals;

the processing unit 12 is further configured to perform DRC (dynamic range control) processing on the at least two subband signals respectively to obtain processed subband signals;

and an output unit 13, configured to superimpose the processed subband signals and output the superimposed subband signals to a speaker.

The audio signal processing apparatus 80 provided in this embodiment of the application can execute the technical solution of the audio signal processing method in any of the above embodiments, and the implementation principle and the beneficial effect thereof are similar to those of the audio signal processing method, and reference may be made to the implementation principle and the beneficial effect of the audio signal processing method, which are not described herein again.

Optionally, the processing unit 12 is specifically configured to:

determining a cut-off frequency of virtual bass in the virtual bass-enhanced audio signal in dependence on a cut-off frequency of the loudspeaker;

Optionally, the number of the subband signals is at least three;

the processing unit 12 is specifically configured to:

Optionally, the processing unit 12 is specifically configured to:

performing virtual bass signal processing on the low-frequency signal to obtain a virtual bass signal;

Optionally, the processing unit 12 is specifically configured to:

Fig. 9 is a schematic structural diagram of an electronic device 90 provided in an embodiment of the present application, for example, please refer to fig. 9, where the electronic device may include a processor 901 and a memory 902; wherein the content of the first and second substances,

the memory 902 is used for storing computer programs.

The processor 901 is configured to read the computer program stored in the memory 902, and execute the technical solution of the audio signal processing method in any of the embodiments according to the computer program in the memory 902.

Alternatively, the memory 902 may be separate or integrated with the processor 901. When the memory 902 is a separate device from the processor 901, the electronic apparatus may further include: a bus for connecting the memory 902 and the processor 901.

Optionally, this embodiment further includes: a communication interface that may be connected with the processor 901 through a bus. The processor 901 may control the communication interface to implement the above-described acquisition and transmission functions of the electronic device.

The electronic device shown in the embodiment of the present application may execute the technical solution of the audio signal processing method in any embodiment, and the implementation principle and the beneficial effects thereof are similar to those of the audio signal processing method, and reference may be made to the implementation principle and the beneficial effects of the audio signal processing method, which are not described herein again.

An embodiment of the present application further provides a computer-readable storage medium, where a computer execution instruction is stored in the computer-readable storage medium, and when a processor executes the computer execution instruction, the technical solution of the audio signal processing method in any of the above embodiments is implemented, and an implementation principle and beneficial effects of the method are similar to those of the audio signal processing method, which can be referred to as the implementation principle and beneficial effects of the audio signal processing method, and are not described herein again.

An embodiment of the present application further provides a computer program product, including a computer program, where when the computer program is executed by a processor, the technical solution of the audio signal processing method in any embodiment is implemented, and an implementation principle and beneficial effects of the computer program are similar to those of the audio signal processing method, and reference may be made to the implementation principle and beneficial effects of the audio signal processing method, which are not described herein again.

Other embodiments of the present application will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the application and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the application being indicated by the following claims.

It will be understood that the present application is not limited to the precise arrangements described above and shown in the drawings and that various modifications and changes may be made without departing from the scope thereof. The scope of the application is limited only by the appended claims.

Claims

1. An audio signal processing method, comprising:

acquiring an original audio signal;

performing Dynamic Range Control (DRC) processing on the at least two sub-band signals respectively to obtain processed sub-band signals;

2. The method of claim 1, wherein the frequency dividing the virtual bass-enhanced audio signal into at least two subband signals comprises:

3. The method of claim 2, wherein the number of subband signals is at least three;

and performing frequency division processing on the audio signal enhanced by the virtual bass according to the first frequency division point, the number of the frequency division points and the frequency division frequency to obtain at least three subband signals.

4. The method of claim 3, wherein the frequency-dividing the virtual bass-enhanced audio signal according to the first frequency-dividing point, the number of frequency-dividing points, and the frequency-dividing frequency to obtain the at least three subband signals comprises:

5. The method of any of claims 1-4, wherein said virtual bass signal processing said original audio signal resulting in a virtual bass enhanced audio signal comprises:

6. The method according to any of claims 1-4, wherein said performing DRC processing on said at least two subband signals, respectively, to obtain processed subband signals comprises:

7. An audio signal processing apparatus, comprising:

an acquisition unit configured to acquire an original audio signal;

the processing unit is further configured to perform frequency division processing on the virtual bass-enhanced audio signal to obtain at least two subband signals;

8. An electronic device comprising a processor and a memory; wherein the content of the first and second substances,

the memory for storing a computer program;

the processor is used for reading the computer program stored in the memory and executing the audio signal processing method of any one of the claims 1 to 6 according to the computer program in the memory.

9. A computer-readable storage medium, wherein computer-executable instructions are stored therein, and when executed by a processor, implement the audio signal processing method according to any one of claims 1 to 6.

10. A computer program product comprising a computer program, characterized in that the computer program, when being executed by a processor, carries out the audio signal processing method of any of the preceding claims 1-6.