WO2020107385A1 - Gain processing method and device implementing same, electronic apparatus, signal acquisition method and system implementing same - Google Patents

Abstract

A gain processing method and a device implementing the same, an electronic apparatus, and a signal acquisition method and a system implementing the same. The gain processing method comprises: analyzing a current audio digital signal to extract a corresponding audio index, and determining an audio index change between the current audio digital signal and an audio digital signal associated with the last update to a gain increase control parameter (S101); and determining, according to the audio index change, whether there is a need to update a gain control parameter used when performing gain processing on the current audio digital signal (S102). The gain processing method can adjust, in real time, a gain control parameter to adapt to the effect of vibrations at the position of a sound source, a sound source change (such as the change of a speaker) or a change in ambient noise, thereby achieving favorable gain control.

Description

Gain processing method and device, electronic equipment, signal acquisition method and system Technical field

Embodiments of the present application relate to the field of signal processing, and in particular, to a gain processing method and apparatus, electronic equipment, signal acquisition method, and system thereof.

Background technique

Audio automatic gain control (Automatic Gain control, hereinafter referred to as AGC) technology has a wide range of applications in audio systems. When the input amplitude of the audio analog signal changes dynamically, adjust the gain of the programmable gain amplifier (Programmable Gain Amplifier, hereinafter referred to as PGA) through AGC technology, so that the amplitude of the audio digital signal after the PGA amplification process is maintained at a stable level, The industry also calls it the target level.

However, in the prior art, fixed control parameters are usually set in advance for the same application scenario to control the gain adjustment, and in the same scenario, there are usually random changes in the actual environment, such as jitter of the sound source position and change of the sound source (For example, the change of the speaker), the change of environmental noise and other factors, if the gain is adjusted according to the preset fixed control parameters, a good gain control effect cannot be achieved.

Summary of the invention

In view of this, one of the technical problems solved by the embodiments of the present application is to provide a gain processing method and its device, electronic equipment, signal acquisition method and its system, to overcome the above-mentioned defects in the prior art.

An embodiment of the present application provides a gain processing method, including:

Analyze the current frame of audio digital signal to extract its corresponding audio index, and determine the change in audio index between the current frame of audio digital signal and the audio digital signal targeted at the last gain control parameter update;

According to the change of the audio index between the current digital audio signal of the current frame and the audio digital signal targeted when the gain control parameter was updated last time, determine whether the gain to be used when the current digital audio signal of the current frame is subjected to gain amplification processing The control parameters are updated.

Optionally, in an embodiment of the present application, the audio index of the current frame of audio digital signals includes at least one of peak-to-peak value of the signal envelope, fluctuation frequency of the signal envelope, and estimated intensity of environmental noise.

Optionally, in an embodiment of the present application, analyzing the current frame of audio digital signal to extract its corresponding audio index includes: analyzing the signal envelope of the current frame of audio digital signal to extract its corresponding The peak-to-peak value of the signal envelope.

Optionally, in an embodiment of the present application, analyzing the current frame of audio digital signal to extract its corresponding audio index includes: performing noise analysis on the current frame of audio digital signal to extract the corresponding estimated intensity of environmental noise .

Optionally, in an embodiment of the present application, analyzing the current frame of audio digital signal to extract its corresponding audio index includes: analyzing the signal envelope of the current frame of audio digital signal to extract its signal package The frequency of the network.

Optionally, in an embodiment of the present application, the method further includes: acquiring a preset audio indicator change limit;

Correspondingly, according to the change of the audio index between the current digital audio signal of the current frame and the audio digital signal targeted when the gain control parameter was last updated, it is determined whether it is necessary to perform gain amplification processing on the current digital audio signal The control parameters of the gain used are updated, including:

According to the change of the audio index between the current frame of audio digital signal and the audio digital signal targeted for the last gain control parameter update and the change of the audio index, determine whether it is necessary to perform gain on the current frame of audio digital signal During the amplification process, the control parameters of the gain used are updated.

Optionally, in an embodiment of the present application, according to the audio index change between the current frame of audio digital signal and the audio digital signal targeted when the gain control parameter was last updated and the audio index change limit To determine whether it is necessary to update the control parameters of the gain used when performing gain amplification processing on the audio signal of the current frame, including:

If the change of the audio index between the current frame of audio digital signal and the audio digital signal targeted for the last gain control parameter update does not exceed the audio index change limit, there is no need to perform the current frame of audio digital signal Update the control parameters of the gain used during the gain amplification process;

Or, if the change of the audio index between the current frame of audio digital signal and the audio digital signal targeted for the last gain control parameter update exceeds the limit of the change of the audio index, the audio digital signal of the current frame needs to be performed During the gain amplification process, the control parameters of the used gain are updated.

Optionally, in an embodiment of the present application, it is necessary to update the control parameters of the gain used when performing gain amplification processing on the current frame of audio digital signals, then the method further includes: determining to update the gain Control parameters used at the time, and updating the control parameters according to the set adjustment rules.

Optionally, in an embodiment of the present application, determining the control parameter used when updating the gain includes: if the current frame of audio digital signal and the audio digital targeted when the control parameter of the gain was last updated If the change in the estimated intensity of the environmental noise between the signals exceeds the limit of the change in the estimated intensity of the environmental noise, then set the control parameter used when updating the gain as the noise threshold;

If the peak-to-peak change of the signal envelope between the current frame of audio digital signal and the audio digital signal targeted at the last gain control parameter update exceeds the peak-to-peak change limit of the signal envelope, or When the fluctuation frequency of the signal envelope between the audio digital signal of the current frame and the audio digital signal targeted for the last gain control parameter update exceeds the fluctuation frequency change limit of the signal envelope, the gain is set to The control parameter used when updating is at least one of a speed parameter when increasing the gain or a speed parameter when decreasing the gain.

Optionally, in an embodiment of the present application, if the control parameter is the noise threshold; correspondingly, updating the control parameter according to the set adjustment rule includes: according to the current frame of audio The estimated noise intensity of the digital signal updates the noise threshold.

Optionally, in an embodiment of the present application, if the control parameter is the speed parameter when increasing the gain; correspondingly, updating the control parameter according to the set adjustment rule includes: The speed parameter when increasing the gain is updated according to the peak-to-peak value of the signal envelope equal to the current frame of the audio digital signal and the fluctuation frequency of the signal envelope.

Optionally, in an embodiment of the present application, if the control parameter is the speed parameter when reducing the gain; correspondingly, updating the control parameter according to the set adjustment rule includes: The speed parameter when reducing the gain is updated according to the peak-to-peak value of the signal envelope equal to the current frame of the audio digital signal and the fluctuation frequency of the signal envelope.

An embodiment of the present application also provides a signal acquisition method, which includes:

Perform analog-to-digital conversion on the current frame of audio analog signals to generate corresponding audio digital signals;

Analyze the current frame of audio digital signal to extract its corresponding audio index, and determine the change in audio index between the current frame of audio digital signal and the audio digital signal targeted at the last gain control parameter update;

According to the change of the audio index between the current digital audio signal of the current frame and the audio digital signal targeted when the gain control parameter was updated last time, determine whether the gain to be used when the current digital audio signal of the current frame is subjected to gain amplification processing To update the control parameters;

Amplify the audio signal of the current frame according to the gain.

An embodiment of the present application further provides a gain adjustment device, including:

The extraction unit is used to analyze the current frame of audio digital signal to extract its corresponding audio index and determine the relationship between the current frame of audio digital signal and the audio digital signal targeted for the last gain control parameter update Audio index changes;

The analysis unit is used for determining whether it is necessary to perform gain amplification processing on the current frame of audio digital signal according to the change of the audio index between the current frame of audio digital signal and the audio digital signal targeted when the gain control parameter was updated last time The control parameters of the gain used are updated.

An embodiment of the present application also provides a signal acquisition system, which includes:

Analog-to-digital conversion module, used for analog-to-digital conversion of the current frame of audio analog signals to generate corresponding audio digital signals;

Gain adjustment device, including an extraction unit and an analysis unit, the extraction unit is used to analyze the current frame of audio digital signal to extract its corresponding audio index, and determine the current frame of audio digital signal and the last gain The audio index changes between the audio digital signals targeted when the control parameters are updated; the analysis unit is used to determine the relationship between the audio digital signals of the current frame and the audio digital signals targeted during the last gain control parameter update The audio index changes to determine whether it is necessary to update the gain control parameters used when the current frame of audio digital signal is gain amplified;

A gain amplification module is used to amplify the current frame of audio digital signal according to the gain.

An embodiment of the present application also provides an electronic device, which includes the signal acquisition system described in the embodiment of the present application.

In the embodiment of the present application, when determining whether it is necessary to adjust the gain control parameters, the current frame of audio digital signal is analyzed to extract its corresponding audio index, and it is determined that the current frame of audio digital signal is the same as the last time The audio index changes between the audio digital signals targeted when the gain control parameter is updated, and then further based on the audio index changes between the current frame of audio digital signals and the audio digital signals targeted when the gain control parameter was last updated To determine whether it is necessary to update the control parameters of the gain used when performing gain amplification processing on the current frame of audio digital signal, therefore, it can adaptively respond to the jitter of the sound source position, the change of the sound source (such as the change of the speaker), Under the influence of factors such as changes in environmental noise, the above-mentioned gain control parameters are adjusted in real time to achieve a good gain control effect.

BRIEF DESCRIPTION

Hereinafter, some specific embodiments of the embodiments of the present application will be described in detail in an exemplary but non-limiting manner with reference to the drawings. The same reference numerals in the drawings indicate the same or similar parts or portions. Those skilled in the art should understand that these drawings are not necessarily drawn to scale. In the drawings:

[Corrected according to Rule 26. 25.01.2019]
1 is a schematic structural diagram of a signal acquisition system according to an embodiment of this application;

[Corrected according to Rule 26. 25.01.2019]
2 is a schematic flowchart of a gain processing method according to an embodiment of the present application;

[Corrected according to Rule 26. 25.01.2019]
3 is a schematic flowchart of a gain processing method according to Embodiment 2 of the present application;

[Corrected according to Rule 26. 25.01.2019]
4 is a schematic flowchart of a third gain processing method according to an embodiment of this application;

[Corrected according to Rule 26. 25.01.2019]
FIG. 5 is a schematic flowchart of a fourth gain processing method according to Embodiment 4 of the present application.

detailed description

It is not necessary for all technical solutions of the embodiments of the present application to achieve all the above advantages at the same time.

In the embodiment of the present application, when determining whether it is necessary to adjust the gain control parameters, the current frame of audio digital signal is analyzed to extract its corresponding audio index, and it is determined that the current frame of audio digital signal is the same as the last time The audio index changes between the audio digital signals targeted when the gain control parameter is updated, and then further based on the audio index changes between the current frame of audio digital signals and the audio digital signals targeted when the gain control parameter was last updated To determine whether it is necessary to update the control parameters of the used gain when performing gain amplification processing on the current frame of audio digital signals, therefore, it can adaptively respond to changes in the sound source position, changes in the sound source (such as the change of the speaker) Under the influence of factors such as changes in environmental noise, the above-mentioned gain control parameters are adjusted in real time to achieve a good gain control effect.

FIG. 0 is a schematic structural diagram of a signal acquisition system according to an embodiment of the present application; as shown in FIG. 0, it includes:

Analog-to-digital conversion module (also known as AD converter), used for analog-to-digital conversion of the current frame of audio analog signals to generate corresponding audio digital signals;

A gain adjustment device (also known as an AGC analysis module) includes an extraction unit and an analysis unit. The extraction unit is used to analyze the current frame of audio digital signal to extract its corresponding audio index and determine the current The change of the audio index between the audio digital signal of one frame and the audio digital signal targeted when the control parameter of the last gain is updated; the analysis unit is used to determine the control parameter of the gain according to the current audio digital signal of the current frame During the update, the audio index changes between the audio digital signals to determine whether it is necessary to update the gain control parameters used when the current frame of audio digital signals is subjected to gain amplification processing;

A gain amplification module (also called PGA) is used to amplify the current frame of audio digital signal according to the gain.

The above-mentioned audio collection system in the first embodiment can be applied to but not limited to: 1) the noise intensity changes obviously; 2) the audio loudness may change at a high frequency. among them:

The scenario 1) specifically includes but is not limited to: the audio collection system is integrated into a portable microphone, and the user carries the microphone into different environments to perform audio collection activities. The different environments may be but not limited to schools, shopping malls, vegetable markets, conference rooms, etc.

The scenario 2) includes but is not limited to: the audio collection system is integrated into a portable microphone. During the audio collection process, the relative position of the microphone and the sound source changes at a certain frequency, such as the shaking of the microphone, resulting in the collection The loudness of the audio frequency also fluctuates at this frequency.

The output of the audio collection system may be, but not limited to: 1) converted to an analog signal by a D/A converter and played directly; 2) encoded by an encoder, and then saved as an audio file or sent to a remote end through a wireless network Equipment; 3) After the subsequent speech enhancement algorithm processing, to get a clearer speech.

It can be seen from the above that when determining whether it is necessary to adjust the gain control parameters, the current frame of audio digital signal is analyzed to extract its corresponding audio index, and the current frame of audio digital signal and the last gain gain are determined The audio index changes between the audio digital signals targeted when the control parameters are updated, and then further determined according to the audio index changes between the current frame of audio digital signals and the audio digital signals targeted when the control parameters were updated last time Whether it is necessary to update the control parameters of the gain used when performing gain amplification processing on the current frame of audio digital signals, therefore, the audio acquisition system in the first embodiment above can adaptively respond to the position of the sound source during the signal acquisition process The influence of factors such as the jitter of the sound source, the change of the sound source (such as the change of the utterer), the change of the environmental noise, etc., adjust the above-mentioned gain control parameters in real time to achieve a good gain control effect.

Corresponding to the above signal acquisition system, an embodiment of the present application also provides a signal acquisition method, which includes the following steps: performing analog-to-digital conversion on the current frame of audio analog signals to generate corresponding audio digital signals; and analyzing the current frame of audio digital signals To extract the corresponding audio index and determine the audio index change between the current frame of audio digital signal and the audio digital signal targeted at the last gain control parameter update; according to the current frame of audio digital signal and The audio index changes between the audio digital signals for the last time when the control parameters of the gain were updated, to determine whether it is necessary to update the control parameters of the used gain when performing gain amplification processing on the current frame of audio digital signals; and The gain amplifies the audio signal of the current frame.

Corresponding to the gain adjustment device in the above-mentioned signal acquisition system, an embodiment of the present application provides a gain processing method. FIG. 1 is a schematic flowchart of the gain processing method in Embodiment 1. As shown in FIG. 1, it specifically includes the following steps:

S101. Analyze the current frame of audio digital signal to extract its corresponding audio index, and determine the change of the audio index between the current frame of audio digital signal and the audio digital signal targeted when the gain control parameter was last updated ;

S102: Determine whether it is necessary to use the gain amplification processing of the current frame of audio digital signal according to the change of the audio index between the current frame of audio digital signal and the audio digital signal targeted when the gain control parameter was updated last time The gain control parameters are updated.

In this embodiment, the audio index of the current frame of audio digital signals includes but is not limited to at least one of the peak-to-peak value of the signal envelope, the fluctuation frequency of the signal envelope, and the estimated intensity of environmental noise. After analyzing the current frame of audio digital signals and extracting at least one of the peak value of the signal envelope, the fluctuation frequency of the signal envelope, and the estimated intensity of environmental noise, determine the current frame of audio digital signals and the last gain The corresponding audio index changes between the audio digital signals targeted when the control parameters are updated.

In the following embodiments, how to use the gain adjustment device in the above-mentioned signal acquisition system to implement the process of gain adjustment will be exemplified as follows. When it is necessary to update the control parameters of the gain used in the current frame of audio digital signals during gain amplification, how to determine the control parameters used to update the gain, and update the control parameters according to the set adjustment rules are as follows Exemplary instructions.

FIG. 2 is a schematic flowchart of a gain processing method according to Embodiment 2 of the present application; as shown in FIG. 2, it includes the following steps S201-205A, or, steps S201-205B:

S201. Analyze the current frame of audio digital signal to extract the peak-to-peak value of its corresponding signal envelope;

In this embodiment, analyzing the current frame of audio digital signal may include analyzing the signal envelope of the current frame of audio digital signal to extract the peak-to-peak value of the signal envelope. In step S201 or before step S201, it may further include: performing an envelope analysis on the current frame of audio digits based on the Hilbert transform method or the complex analytical wavelet transform method to obtain the signal envelope.

In this embodiment, the peak-to-peak value of the signal envelope can reflect the change in the strength of the audio digital signal (also known as the change in audio loudness), which is the maximum difference between the adjacent peak value and the valley value of the signal envelope within the set time period value. In a specific application scenario, the duration of the current frame of audio digital signals can be set according to actual conditions, and can be from a few hundred milliseconds to tens of seconds.

S202. Determine the peak-to-peak change of the signal envelope between the audio signal of the current frame and the audio digital signal targeted when the gain control parameter was updated last time;

In this embodiment, the gain control parameters include at least the speed parameter when reducing the gain. Further, in specific applications, it is not necessary to use the time to reduce the gain when processing each frame of audio digital signals The speed parameter is updated. In fact, there are often several frames of audio digital signals corresponding to an audio stream. For the multi-frame audio digital signal (the multi-frame audio digital signal is not necessarily continuous), when reducing the gain The speed parameter needs to be updated, and the speed parameter for reducing the gain used for another multi-frame audio digital signal (the other multi-frame audio digital signal is not necessarily continuous) does not need to be updated. Therefore, in this embodiment, the audio digital signal targeted when the speed parameter update when the gain is reduced last time may be the audio digital signal of the previous frame that has an adjacent relationship with the audio digital signal of the current frame, and may be A frame of audio digital signals with a space relationship in the current frame of audio digital signals.

Of course, in other embodiments, it is not ruled out that it is necessary to update the speed parameter when reducing the gain used in processing each frame of audio digital signals.

S203. Acquire a preset peak-to-peak variation limit of the signal envelope;

In this embodiment, the peak-to-peak change limit of the signal envelope may be a single peak-to-peak change threshold of the signal envelope (or the peak-to-peak change threshold of the signal envelope), or may be a signal envelope with upper and lower limits The peak-to-peak variation range of the signal, the peak-to-peak variation threshold of the signal envelope, and the specific values of the upper and lower limits of the peak-to-peak variation range of the signal envelope are flexibly set according to empirical statistics of actual application scenarios. Of course, the threshold of the peak-to-peak change of the signal envelope and the upper and lower limits of the peak-to-peak change range of the signal envelope can be adjusted manually or adaptively according to different application scenarios.

S204. Determine whether the peak-to-peak change of the signal envelope between the current frame of audio digital signal and the audio digital signal targeted for the last gain control parameter update exceeds the peak-to-peak change limit of the signal envelope, if If it is exceeded, step S205A is executed; otherwise, step S205B is executed.

In this embodiment, in order to make it clear that the frame order is not limited, the audio digital signal of the current frame may also be referred to as the audio digital signal of the first frame, and the audio digital signal targeted when the gain control parameter was last updated It can be called the second frame audio digital signal. Therefore, in step S202, the peak-to-peak value of the signal envelope of the first frame audio digital signal can be directly compared with the peak-to-peak value of the signal envelope of the second frame audio digital signal to determine this The peak-to-peak variation of the signal envelope of the two frames of audio digital signals. The corresponding number can be the absolute value of the difference between the peak and peak values of the signal envelope of the first frame of audio digital signals and the second frame of audio digital signals. Compare with the peak-to-peak change limit of the signal envelope to further determine whether the peak-to-peak change of the signal envelope of the audio digital signal of the first frame exceeds the preset signal envelope in step S204 through a judgment process Peak-to-peak variation limits.

S205A. It is necessary to update the control parameters of the gain used when performing gain amplification processing on the current frame of audio digital signals, and set the control parameters used when updating the gain to be the speed parameter when reducing the gain, and according to the settings The adjustment rule of updates the speed parameter when reducing the gain.

For this embodiment, in step 205A, the adjustment rule includes the speed parameter that is equal to the peak-to-peak value of the signal envelope of the current frame of audio digital signal and the fluctuation frequency of the signal envelope when the gain is reduced. The control parameter of the gain mentioned in step 204 and the related steps before it is specifically the speed parameter when reducing the gain when the amplitude of the amplified audio digital signal exceeds the target level, in this embodiment the gain is reduced The speed parameter of time is used to control the speed of reducing the PGA gain by AGC technology when the audio digital signal exceeds the target level. In a specific application scenario, the speed parameter of reducing the gain is also called Attack time.

Further, the control parameter may be updated according to the set adjustment rule. Specifically, the following formula (1) may be used to update the speed parameter when reducing the gain:

t _attack = t _a0 -k _a ×env×f (1)

In the above formula (1), for the current frame of audio digital signals, t _attack represents Attack time, t _a0 represents the maximum value of Attack time, env represents the peak-to-peak value of the signal envelope of the current frame of audio digital signals, and f represents The fluctuation frequency of the signal envelope of the current frame of audio digital signals. k _a represents the coefficient of attack time varying with env×f. Among them, t _a0 and k _a are constant parameters, and the specific values of the constant parameters are manually set by the designer according to actual needs or obtained through debugging software testing.

In this embodiment, the relationship between t _attack and env and f is not limited to the proportional relationship described above, but may also be other negative correlations. It should be noted that the adjustment rules of the update control parameters set in this embodiment are only exemplary descriptions. In actual use, those skilled in the art can refer to the solutions in the embodiments of the present application on the premise of not paying any creative labor. , Other adjustment rules for updating control parameters can be obtained according to the adjustment rules.

The fluctuation frequency f of the signal envelope in the above formula (1) can also be obtained by statistically calculating the signal envelope within a set time period. In this embodiment, it is assumed that the fluctuation frequency of the signal envelope of the audio digital signal of the current frame is unchanged or relatively small with respect to the fluctuation frequency of the signal envelope of the audio digital signal for the last gain control parameter update.

In other embodiments, for the current frame of audio digital signals, the fluctuation frequency f of the signal envelope may also be relative to the fluctuation frequency of the signal envelope of the audio digital signal targeted at the last gain control parameter update When a change occurs, when the change of the undulation frequency exceeds the set undulation frequency change limit, it can be based on the above formula (1) and at the same time according to the undulation frequency f of the signal envelope of the current frame of audio digital signal and the signal envelope The peak-to-peak value env updates the attack time, the speed parameter when reducing the gain.

In this embodiment, t _{attack is} recalculated through the above formula (1), and when the peak-to-peak value of the signal envelope becomes larger, the value of t _attack becomes smaller than the t _attack used in the last update, that is, minus The small PGA gain needs a shorter time, that is, the PGA gain needs to be quickly reduced, so that the audio digital signal quickly falls back to the target level when it is amplified, thereby avoiding the effect of "suppressing and frustrating".

S205B. It is not necessary to update the speed parameter when reducing the gain when performing gain amplification processing on the audio signal of the current frame.

In this embodiment, if there is no need to update the speed parameter at the time of reducing the gain, the speed parameter at the time of reducing the gain obtained when the control parameter of the gain was last updated is continued.

FIG. 3 is a schematic flowchart of a third gain processing method according to an embodiment of the present application; as shown in FIG. 3, it includes the following steps S301-305A, or, steps S301-305B:

S301. Analyze the audio digital signal of the current frame to extract the fluctuation frequency of its signal envelope.

In this embodiment, analyzing the current frame of audio digital signals may include analyzing the signal envelope of the current frame of audio digital signals to extract the fluctuation frequency of the signal envelope. The fluctuation frequency of the signal envelope can reflect the speed of the change of the intensity of the audio digital signal (also known as the speed of the change of the audio loudness).

In this embodiment, similar to the above embodiment, the specific signal envelope may be obtained based on signal envelope analysis methods such as the Hilbert transform method or the complex analytical wavelet transform method.

S302: Determine the fluctuation frequency of the signal envelope between the audio signal of the current frame and the audio digital signal targeted at the last time when the control parameter of the gain is updated;

In this embodiment, the gain control parameters include at least the speed parameter when increasing the gain. Further, similar to the above embodiment, in specific applications, it is not necessary to process each frame of audio digital signal. The update of the speed parameter when increasing the gain does not exclude the need to update the speed parameter when increasing the gain used for processing each frame of audio digital signal. Therefore, in this embodiment, The audio digital signal targeted at the last time when the gain parameter was updated when the speed was increased may be the audio digital signal of the previous frame that is adjacent to the current frame of audio digital signal, or may be separated from the current frame of audio digital signal A frame of audio digital signals.

Of course, in other embodiments, it is not excluded that it is necessary to update the speed parameter used to increase the gain when processing each frame of audio digital signals.

S303. Acquire a predetermined limit of the fluctuation frequency of the signal envelope;

In this embodiment, similar to the above embodiment, in this embodiment, the fluctuation frequency limit of the signal envelope may be a single fluctuation threshold of the signal envelope (also referred to as the fluctuation threshold of the signal envelope) It can also be the range of fluctuation frequency of the signal envelope with upper and lower limits. The threshold value of the fluctuation frequency of the signal envelope and the specific values of the upper and lower limits of the fluctuation range of the signal envelope can be flexibly set according to the actual application scenarios. set. Of course, the threshold of the fluctuation frequency of the signal envelope and the upper and lower limits of the fluctuation range of the signal envelope can be adjusted manually or adaptively according to different application scenarios.

S304. Determine whether the fluctuation frequency of the signal envelope between the audio signal of the current frame and the audio digital signal targeted for the last gain control parameter update exceeds the fluctuation frequency change limit of the signal envelope, if If it exceeds, step S305A is executed; otherwise, step S305B is executed.

With reference to the second embodiment above, in this embodiment, for the sake of clarity, it does not limit the frame order. The current frame of audio digital signal is called the first frame of audio digital signal. The audio digital signal can also be called the second frame audio digital signal. Therefore, in step S302, the fluctuation frequency of the signal envelope of the first frame audio digital signal can be directly compared with the fluctuation of the signal envelope of the second frame audio digital signal Frequency to determine the fluctuation frequency of the signal envelope of the two frames of audio digital signals, the corresponding number can be the difference between the fluctuation frequency of the signal envelope of the first frame of audio digital signals and the second frame of audio digital signals The absolute value is compared with the fluctuation limit of the signal envelope in step S304 to further determine whether the change of the fluctuation frequency of the signal envelope of the audio digital signal of the first frame exceeds the preset signal envelope The limit of the frequency fluctuation.

S305A. It is necessary to update the control parameters of the gain used when performing gain amplification processing on the audio signal of the current frame, set the control parameters used when updating the gain to be the speed parameter when increasing the gain, and according to the settings The adjustment rule of updates the speed parameter when increasing the gain.

For this embodiment, in step 305A, the adjustment rule includes the peak-to-peak value of the signal envelope of the audio digital signal of the current frame and the fluctuation frequency of the signal envelope update the speed parameter when increasing the gain. The control parameters of the gain mentioned in step 304 and the related steps above specifically refer to the speed parameter when increasing the gain. In this embodiment, the speed parameter when increasing the gain is used to control the audio frequency digital signal. When it is lower than the target level, the speed of increasing the PGA gain by means of AGC technology. In a specific application scenario, the speed parameter when increasing the gain is also called Decay time.

Further, the control parameter may be updated according to the set adjustment rule. Specifically, the following formula (2) may be used to update the speed parameter when increasing the gain:

t _decay = t _d0 -k _d ×env×f (2)

In the above formula (2), for the current frame of audio digital signals, t _decay represents Decay time, t _d0 represents the maximum value of Decay time, and env represents the peak-to-peak value of the signal envelope of the current frame of audio digital signals, f represents the fluctuation frequency of the signal envelope of the current frame of audio digital signal, and k _d represents the coefficient of Decay time varying with env×f. Among them, t _d0 and k _d are constant parameters, and the specific values of the constant parameters are manually set by the designer according to actual needs or obtained through debugging software testing.

In this embodiment, the relationship of the change of t _decay with env and f is not limited to the proportional relationship described above, but may also be other negative correlations. It should be noted that the adjustment rules of the update control parameters set in this embodiment are only exemplary descriptions. In actual use, those skilled in the art can refer to the solutions in the embodiments of the present application on the premise of not paying any creative labor. , Other adjustment rules for updating control parameters can be obtained according to the adjustment rules.

The peak-to-peak value of the signal envelope in the above formula (2) can also be obtained by referring to the above embodiment. In this embodiment, it is assumed that the peak-to-peak value of the signal envelope of the current frame of audio digital signal is The peak-to-peak value of the signal envelope of the audio digital signal for which the control parameter update of the gain is updated does not change or changes little.

In other embodiments, for the current frame of audio digital signals, the peak-to-peak value of the signal envelope of the env may also be relative to the peak-to-peak value of the signal envelope of the audio digital signal when the control parameter of the last gain is updated env changes, when the peak-to-peak change of the signal envelope exceeds the set peak-to-peak change limit, it can be based on the above formula (2), and at the same time according to the fluctuation frequency f of the signal envelope of the current frame of audio digital signal and The peak-to-peak value of the signal envelope env updates the Decay time parameter when increasing the gain.

In this embodiment, t _{decay is} recalculated through the above formula (2). When the fluctuation frequency of the signal envelope becomes larger, its value becomes smaller than the t _decay used in the last update, that is, increases. The large PGA gain needs a shorter time, that is, the PGA gain needs to be increased quickly, so that the audio digital signal quickly rises to the target level when it is amplified, thereby avoiding the effect of "suppressing and frustrating".

S305B. It is not necessary to update the speed parameter when increasing the gain when performing gain amplification processing on the audio signal of the current frame.

In this embodiment, if there is no need to update the speed parameter when increasing the gain, the speed parameter when increasing the gain obtained when the control parameter of the gain was last updated is continued.

With reference to the second and third embodiments above, it is assumed that one of the peak-to-peak value of the signal envelope env and the fluctuation frequency f of the signal envelope is unchanged or the change is small, which can be regarded as approximately unchanged. Of course, in other embodiments, the peak-to-peak value of the signal envelope env and the fluctuation frequency f of the signal envelope can also be considered as a comprehensive audio index. When the comprehensive audio index for the current frame of audio digital signal is relatively The change between the comprehensive audio index of the audio digital signal last updated exceeds the set comprehensive audio index change limit, then refer to formulas (1) and (2) to adjust the speed parameter and the increase rate when reducing the gain, respectively The speed parameter when the gain is large.

In the second and third embodiments described above, only one of the speed parameter at the time of decreasing the gain and the speed parameter at the time of increasing the gain are described, and the other speed parameter remains unchanged. However, in some In an application scenario, the speed parameters when the gain is reduced and the speed parameters when the gain is increased may be updated together with reference to the above formulas (1) and (2).

In other embodiments, when the peak-to-peak change of the signal envelope between the audio signal of the current frame and the audio digital signal for which the gain control parameter was last updated exceeds the limit of the peak-to-peak change of the signal envelope, The control parameters used when updating the gain can be set as the speed parameter when reducing the gain and the speed parameter when increasing the gain, and the speed when reducing the gain can be adjusted according to the set adjustment rule The parameters are updated together with the speed parameter when increasing the gain. The adjustment rules include the peak-to-peak value of the signal envelope equal to the current frame of the audio digital signal and the fluctuation frequency of the signal envelope are updated when the gain is reduced Speed parameter and speed parameter when increasing the gain, specifically, refer to the above formulas (1) and (2) for the speed parameter when decreasing the gain and the speed parameter when increasing the gain And update, please refer to the second and third embodiments above for details.

In other embodiments, when the fluctuation frequency of the signal envelope between the audio digital signal of the current frame and the audio digital signal targeted for the last gain control parameter update exceeds the fluctuation frequency change limit of the signal envelope, The control parameters used when updating the gain can be set as the speed parameter when reducing the gain and the speed parameter when increasing the gain, and the speed when reducing the gain can be adjusted according to the set adjustment rule The parameters are updated together with the speed parameter when increasing the gain. The adjustment rules include the peak-to-peak value of the signal envelope equal to the current frame of the audio digital signal and the fluctuation frequency of the signal envelope are updated when the gain is reduced Speed parameter and speed parameter when increasing the gain, specifically, refer to the above formulas (1) and (2) for the speed parameter when decreasing the gain and the speed parameter when increasing the gain And update, please refer to the second and third embodiments above for details.

In other embodiments, the difference from the above-mentioned second embodiment is: in the above-mentioned second embodiment, the peak of the signal envelope between the audio signal of the current frame and the audio digital signal targeted at the last time when the gain control parameter is updated When the peak change exceeds the peak-to-peak change limit of the signal envelope, the control parameter used when updating the gain is set as the speed parameter when reducing the gain, it should be noted that it can also be used when updating the gain The control parameter of is only the speed parameter when increasing the gain, and the speed parameter when increasing the gain is updated according to the set adjustment rule, the adjustment rule includes a signal equal to the current frame of audio digital signal The peak-to-peak value of the envelope and the fluctuation frequency of the signal envelope update the speed parameter when increasing the gain. Specifically, you can also refer to the above formula (2) to update only the speed parameter when increasing the gain. For details, refer to the above Examples two and three.

In other embodiments, the difference from the above-mentioned third embodiment is: in the above-mentioned third embodiment, the fluctuation of the signal envelope between the audio signal of the current frame and the audio digital signal targeted when the gain control parameter was last updated When the frequency change exceeds the fluctuating frequency change limit of the signal envelope, the control parameter used when updating the gain is set as the speed parameter when increasing the gain, it should be noted that it can also be used when updating the gain The control parameter of is only the speed parameter when reducing the gain, and the speed parameter when reducing the gain is updated according to the set adjustment rule. The adjustment rule includes a signal packet equal to the current frame of audio digital signal The peak-to-peak value of the network and the fluctuation frequency of the signal envelope are updated to reduce the speed parameter of the gain. Specifically, the above formula (1) may also be used to update only the speed parameter of the gain reduction. Examples two and three.

FIG. 4 is a schematic flowchart of a gain processing method according to Embodiment 4 of the present application; as shown in FIG. 4, it includes the following steps S401-405A, or, steps S401-405B:

S401. Analyze the current frame of audio digital signals to extract the corresponding estimated intensity of environmental noise.

In this embodiment, analyzing the current frame of audio digital signal may include performing noise analysis on the current frame of audio digital signal to extract the corresponding estimated intensity of environmental noise. Specifically, noise analysis methods such as minimum value tracking algorithm, time recursive averaging algorithm, and quantile noise estimation can be used to perform noise analysis on the current frame of audio digital signal to obtain the estimated intensity of environmental noise.

S402. Determine the change in the estimated intensity of the environmental noise between the audio signal of the current frame and the audio digital signal targeted when the gain control parameter was last updated;

In this embodiment, the gain control parameter includes at least a noise threshold. Further, similar to the above embodiment, in specific applications, it is not necessary to update the noise threshold used when processing each frame of audio digital signal. Of course It does not rule out the need to update the noise threshold used when processing each frame of audio digital signal. Therefore, in this embodiment, the audio digital signal targeted for the last noise threshold update may be the same as the current frame of audio digital signal. The audio digital signal of the previous frame with an adjacent relationship may be a frame of audio digital signal with an interval relationship with the audio digital signal of the current frame.

Of course, in other embodiments, it is not excluded that the noise threshold used when processing each frame of audio digital signal needs to be updated.

S403. Acquire a preset limit of change in the estimated intensity of environmental noise;

In this embodiment, the environmental noise estimated intensity change limit may be a single environmental noise estimated intensity change threshold (or also referred to as the environmental noise estimated intensity change threshold), or it may be an environmental noise estimated intensity change range with upper and lower limits, The threshold value of the variation intensity of the estimated environmental noise and the specific values of the upper and lower limits of the variation range of the estimated intensity of the environmental noise are flexibly set according to empirical statistics of actual application scenarios. Of course, the threshold of the change in the intensity of the environmental noise estimate and the upper and lower limits of the range of the change in the intensity of the environmental noise estimate can be adjusted manually or adaptively according to different application scenarios.

S404. Determine whether the change in the estimated intensity of the environmental noise between the current frame of the digital audio signal and the audio digital signal targeted at the last time when the control parameter of the gain was updated exceeds the limit of the change in the estimated intensity of the environmental noise. S405A, otherwise, execute S405B.

With reference to the second embodiment above, in this embodiment, for the sake of clarity, it does not limit the frame order. The current frame of audio digital signal is called the first frame of audio digital signal. The audio digital signal may also be referred to as a second frame audio digital signal. Therefore, in step S402, the estimated environmental noise intensity of the first frame audio digital signal and the second frame audio digital signal may be directly compared to determine this The estimated intensity of the environmental noise of the two frames of audio digital signal changes, and the corresponding number may be the absolute value of the difference between the estimated intensity of the environmental noise of the audio signal of the first frame and the second frame of the audio digital signal, and then in step S404 A comparison is made with the change limit of the estimated intensity of the environmental noise to further determine whether the change in the estimated intensity of the environmental noise of the first frame of the audio digital signal exceeds the preset limit of the change of the estimated intensity of the environmental noise.

S405A. It is necessary to update the control parameters of the gain used when performing gain amplification processing on the current frame of audio digital signal, set the control parameter used when updating the gain to be a noise threshold, and adjust the noise according to the set adjustment rule The threshold is updated.

For this embodiment, in step 405A, the adjustment rule includes updating the noise threshold proportional to the estimated intensity of the environmental noise of the current frame of audio digital signal. The noise threshold (also referred to as noise threshold) mentioned in step 404 and the related steps before it specifically refers to identifying noise from the audio digital signal. For example, when the amplitude of the audio digital signal is lower than the noise threshold, it is considered It's noise. If the noise threshold is set too high, then the smaller audio digital signal will be considered as noise and ignored; if the noise threshold is set too low, then the larger noise will be significantly amplified. In a specific application scenario, the noise threshold is also called Noise threshold.

In this embodiment, further, the control parameter may be updated according to the set adjustment rule, specifically the noise threshold may be updated by the following formula (3):

noise _thr = k×noise _est (3)

Among the above formula (3), for the current frame of audio digital signal, noise _thr represents Noise threshold, noise _est represents the estimated intensity of environmental noise, k represents the coefficient of variation of Noise threshold with the estimated intensity of environmental noise, where k is a constant parameter The specific value of the constant parameter is set by the designer according to actual needs or obtained through debugging software test.

It should be noted that in other embodiments, the relationship between noise _thr and noise _est is not limited to the proportional relationship described above, but may also be other positive correlation relationships. It should be noted that the adjustment rules of the update control parameters set in this embodiment are only exemplary descriptions. In actual use, those skilled in the art can refer to the solutions in the embodiments of the present application on the premise of not paying any creative labor. , Other adjustment rules for updating control parameters can be obtained according to the adjustment rules.

In this embodiment, the noise threshold is recalculated through the above formula (3). In the case where the estimated intensity of the environmental noise becomes larger, compared with the noise threshold used in the last update, for the current frame of audio digital signal The noise threshold of becomes larger, so as to avoid larger noise from being amplified.

S405B. It is not necessary to update the noise threshold when performing gain amplification processing on the audio signal of the current frame.

In this embodiment, if there is no need to update the noise threshold, the noise threshold obtained when the control parameter of the gain was last updated is continued.

It should be noted that in this embodiment, in addition to updating the noise threshold, it may also include updating one or more other related parameters of the control noise, such as maximum gain, maximum hysteresis, and noise. Anti-jitter time (Noise debounce time) and signal anti-jitter time (Signal debounce time), etc.

It should be noted that, in another embodiment, when updating the noise threshold, any one of the speed parameter when increasing the gain or the speed parameter when decreasing the gain may also be updated, or A situation may occur in which the noise threshold, the speed parameter when increasing the gain, and the speed parameter when decreasing the gain are updated together (or referred to as adjustment). For detailed solutions, refer to Embodiments 2 to 4 above. Records.

In the above embodiment, it is assumed that the target level does not need to be adjusted.

In other embodiments, based on the above embodiments, in some application scenarios, such as but not limited to, the audio environment is relatively stable, the audio collection system needs to enter a low-power mode, and the audio collection system needs to free up more The CPU resources are used to process other tasks, and a step to determine whether to stop updating the gain control parameters can also be added. Specifically, whether to stop can be judged by capturing a stop operation command, which can be issued by the controller of the audio collection system or triggered by an external control button.

The processing method adopted by the present invention can be realized not only by AGC hardware, but also by AGC software.

Embodiments of the present application also provide an electronic device that uses the above audio acquisition system or that separately applies the above gain adjustment device. The electronic device exists in various forms, including but not limited to:

(1) Mobile communication equipment: The characteristic of this type of equipment is that it has mobile communication functions, and its main goal is to provide voice and data communication. Such terminals include: smart phones (such as iPhone), multimedia phones, functional phones, and low-end phones.

(2) Ultra-mobile personal computer equipment: This type of equipment belongs to the category of personal computers, has computing and processing functions, and generally has the characteristics of mobile Internet access. Such terminals include: PDA, MID and UMPC devices, such as iPad.

(3) Portable entertainment devices: These devices can display and play multimedia content. Such devices include: audio, video players (such as iPod), handheld game consoles, e-books, and smart toys and portable car navigation devices.

(4) Server: a device that provides computing services. The composition of the server includes a processor 810, hard disk, memory, system bus, etc. The server is similar to a general-purpose computer architecture, but due to the need to provide highly reliable services, the processing power and stability The requirements for performance, reliability, security, scalability, and manageability are high.

(5) Other electronic devices with data interaction function.

So far, specific embodiments of the subject matter have been described. Other embodiments are within the scope of the following claims. In some cases, the actions recited in the claims can be performed in a different order and still achieve the desired results. Additionally, the processes depicted in the drawings do not necessarily require the particular order shown, or sequential order, to achieve the desired results. In certain embodiments, multitasking and parallel processing may be advantageous.

It should also be noted that the terms "include", "include" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device that includes a series of elements includes not only those elements, but also includes Other elements not explicitly listed, or include elements inherent to this process, method, commodity, or equipment. Without more restrictions, the element defined by the sentence "include one..." does not exclude that there are other identical elements in the process, method, commodity, or equipment that includes the element.

The embodiments in this specification are described in a progressive manner. The same or similar parts between the embodiments can be referred to each other. Each embodiment focuses on the differences from other embodiments. In particular, for the system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant part can be referred to the description of the method embodiment.

The above are only examples of the present application, and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of this application shall be included in the scope of the claims of this application.

Claims (16)

1. A gain processing method, characterized in that it includes:

   Analyze the current frame of audio digital signal to extract its corresponding audio index, and determine the change in audio index between the current frame of audio digital signal and the audio digital signal targeted at the last gain control parameter update;

   According to the change of the audio index between the current digital audio signal of the current frame and the audio digital signal targeted when the gain control parameter was updated last time, determine whether the gain to be used when the current digital audio signal of the current frame is subjected to gain amplification processing The control parameters are updated.
2. The method according to claim 1, wherein the audio index of the current frame of audio digital signals includes at least one of a peak-to-peak value of the signal envelope, a fluctuation frequency of the signal envelope, and an estimated intensity of environmental noise.
3. The method according to claim 2, characterized in that analyzing the current frame of audio digital signal to extract its corresponding audio index comprises: analyzing the signal envelope of the current frame of audio digital signal to extract its signal package Peak-to-peak value of the network.
4. The method according to claim 2, wherein analyzing the current frame of audio digital signal to extract its corresponding audio index includes: performing noise analysis on the current frame of audio digital signal to extract the corresponding estimated intensity of environmental noise .
5. The method according to claim 2, characterized in that analyzing the current frame of audio digital signal to extract its corresponding audio index comprises: analyzing the signal envelope of the current frame of audio digital signal to extract its signal package The frequency of the network.
6. The method according to any one of claims 1 to 5, further comprising: obtaining a preset change limit of the audio index;

   Correspondingly, according to the change of the audio index between the current digital audio signal of the current frame and the audio digital signal targeted when the gain control parameter was last updated, it is determined whether it is necessary to perform gain amplification processing on the current digital audio signal The control parameters of the gain used are updated, including:

   According to the change of the audio index between the current frame of audio digital signal and the audio digital signal targeted for the last gain control parameter update and the change of the audio index, determine whether it is necessary to perform gain on the current frame of audio digital signal During the amplification process, the control parameters of the gain used are updated.
7. The method according to claim 6, characterized in that, according to the change of the audio index between the audio digital signal of the current frame and the audio digital signal targeted when the gain control parameter was last updated, and the change limit of the audio index To determine whether it is necessary to update the control parameters of the gain used when performing gain amplification processing on the audio signal of the current frame, including:

   If the change of the audio index between the current frame of audio digital signal and the audio digital signal targeted for the last gain control parameter update does not exceed the audio index change limit, there is no need to perform the current frame of audio digital signal Update the control parameters of the gain used during the gain amplification process;

   Or, if the change of the audio index between the current frame of audio digital signal and the audio digital signal targeted for the last gain control parameter update exceeds the limit of the change of the audio index, the audio digital signal of the current frame needs to be performed During the gain amplification process, the control parameters of the used gain are updated.
8. The method according to any one of claims 1 to 7, characterized in that it is necessary to update the control parameters of the gain used when performing gain amplification processing on the current frame of audio digital signals, then the method further comprises: determining Control parameters used when updating the gain, and updating the control parameters according to the set adjustment rule.
9. The method according to claim 8, wherein the control parameters used when determining the update of the gain include:

   If the environmental noise estimated intensity change between the current frame of audio digital signal and the audio digital signal targeted for the last gain control parameter update exceeds the environmental noise estimated intensity change limit, the update of the gain is set The control parameter used at the time is the noise threshold;

   If the peak-to-peak change of the signal envelope between the current frame of audio digital signal and the audio digital signal targeted at the last gain control parameter update exceeds the peak-to-peak change limit of the signal envelope, or When the fluctuation frequency of the signal envelope between the audio digital signal of the current frame and the audio digital signal targeted for the last gain control parameter update exceeds the fluctuation frequency change limit of the signal envelope, the gain is set to The control parameter used when updating is at least one of a speed parameter when increasing the gain or a speed parameter when decreasing the gain.
10. The method according to claim 9, wherein if the control parameter is the noise threshold; correspondingly, updating the control parameter according to the set adjustment rule includes: according to the current frame of audio The estimated noise intensity of the digital signal updates the noise threshold.
11. The method according to claim 9, wherein if the control parameter is the speed parameter when increasing the gain; correspondingly, updating the control parameter according to the set adjustment rule includes: The speed parameter when increasing the gain is updated according to the peak-to-peak value of the signal envelope equal to the current frame of the audio digital signal and the fluctuation frequency of the signal envelope.
12. The method according to claim 9, wherein if the control parameter is the speed parameter when reducing the gain; correspondingly, updating the control parameter according to the set adjustment rule includes: The speed parameter when reducing the gain is updated according to the peak-to-peak value of the signal envelope equal to the current frame of the audio digital signal and the fluctuation frequency of the signal envelope.
13. A signal acquisition method, characterized in that it includes:

    Perform analog-to-digital conversion on the current frame of audio analog signals to generate corresponding audio digital signals;

    Analyze the current frame of audio digital signal to extract its corresponding audio index, and determine the change in audio index between the current frame of audio digital signal and the audio digital signal targeted at the last gain control parameter update;

    According to the change of the audio index between the current digital audio signal of the current frame and the audio digital signal targeted when the gain control parameter was updated last time, determine whether the gain to be used when the current digital audio signal of the current frame is subjected to gain amplification processing To update the control parameters;

    Amplify the audio signal of the current frame according to the gain.
14. A gain adjustment device is characterized by comprising:

    The extraction unit is used to analyze the current frame of audio digital signal to extract its corresponding audio index and determine the relationship between the current frame of audio digital signal and the audio digital signal targeted for the last gain control parameter update Audio index changes;

    The analysis unit is used for determining whether it is necessary to perform gain amplification processing on the current frame of audio digital signal according to the change of the audio index between the current frame of audio digital signal and the audio digital signal targeted when the gain control parameter was updated last time The control parameters of the gain used are updated.
15. A signal acquisition system, characterized in that it includes:

    Analog-to-digital conversion module, used for analog-to-digital conversion of the current frame of audio analog signals to generate corresponding audio digital signals;

    Gain adjustment device, including an extraction unit and an analysis unit, the extraction unit is used to analyze the current frame of audio digital signal to extract its corresponding audio index, and determine the current frame of audio digital signal and the last gain The audio index changes between the audio digital signals targeted when the control parameters are updated; the analysis unit is used to determine the relationship between the audio digital signals of the current frame and the audio digital signals targeted during the last gain control parameter update The audio index changes to determine whether it is necessary to update the gain control parameters used when the current frame of audio digital signal is gain amplified;

    A gain amplification module is used to amplify the current frame of audio digital signal according to the gain.
16. An electronic device, characterized by comprising the signal acquisition system of claim 15.

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