WO2018176654A1 - Gain adjustment method and apparatus, audio coder, and loudspeaker device - Google Patents

Abstract

Disclosed in the present invention are a gain adjustment method and apparatus, an audio coder, and a loudspeaker device. The method comprises: performing clipping detection on a digital audio signal output by an audio coder; calculating, according to the detection result of the clipping detection, the number of sampling points, at which the clipping occurs, of the digital audio signal; and if the number of the sampling points is greater than a set value, reducing an amplifying gain of the audio coder.

Description

Gain adjustment method, device, audio encoder and audio device Technical field

The present invention relates to the field of audio coding technology, and more particularly to a gain adjustment method for an audio encoder, a gain adjustment device for an audio encoder, an audio encoder, and an audio device .

Background technique

An audio encoder is a device that converts an analog audio signal into a digital audio signal. The audio encoder generally includes a signal shaping module, an amplification module, and an analog-to-digital conversion module that are sequentially connected, and the signal shaping module is configured to limit and filter the input analog audio signal, and the amplification module is configured as a signal shaping module. The output signal is amplified, and the analog-to-digital conversion module is arranged to perform analog-to-digital conversion processing on the signal output from the amplifier to obtain a digital audio signal.

Since the amplification module of the existing audio encoder can only perform fixed gain adjustment, the existing audio encoder has the following defects: 1) The dynamic range of the analog audio signal output by the mobile handheld device such as a mobile phone is 0 to 1 Vrms, and the CD player Or the dynamic range of the analog audio signal output by the AV decoder is 0~2Vrms. If the gain of the amplifier is configured according to the latter, when the user uses the mobile handheld device such as a mobile phone as the analog input source, the maximum output power of the sound will be larger than the rated maximum. The power is 6dB, which can't fully play the performance of the sound.

Therefore, it is highly desirable to provide a technical solution for adaptively adjusting the amplification gain of an audio encoder.

Summary of the invention

It is an object of the present invention to provide a technical solution for adaptively adjusting the gain of an audio encoder.

According to a first aspect of the present invention, there is provided a gain adjuster for an audio encoder Law, which includes:

Performing clipping detection on the digital audio signal output by the audio encoder;

Calculating a number of sampling points of the digital audio signal that are clipped according to the detection result of the clipping detection;

If the number of sampling points is greater than a set value, the amplification gain of the audio encoder is reduced.

Optionally, the method further includes:

Detecting whether the audio source device is connected to the analog audio signal input interface of the audio encoder, if yes, first setting the amplification gain of the audio encoder to be equal to a default value, and then starting to cut the digital audio signal output by the audio encoder Wave detection.

Optionally, the method further includes:

Detecting whether the audio source device is connected to the analog audio signal input interface of the audio encoder, such as:

And then start to perform clipping detection on the digital audio signal output by the audio encoder; and

Detecting whether the audio source device disconnects from the analog audio signal input interface, and if so, setting the amplification gain of the audio encoder to be equal to a default value.

Optionally, the reducing the amplification gain of the audio encoder comprises:

The amplification gain of the audio encoder is reduced by a set fixed step.

Optionally, the performing clipping detection on the digital audio signal output by the audio encoder includes:

Reading the value of the sampling point of the digital audio signal;

If the value is greater than or equal to the preset clipping signal reference value, then the sampling point is marked as being clipped.

Optionally, the calculating the number of sampling points where the digital audio signal is clipped comprises:

Calculating a number of sampling points of the continuously occurring clipping of the digital audio signal, wherein the continuously occurring clipping is set to be a sampling point interval between adjacent sampling points where clipping occurs is less than or equal to a preset value; or,

The calculating the number of sampling points where the digital audio signal is clipped includes:

The number of sample points where clipping occurs in each successive number of sets of the digital audio signal is calculated.

According to a second aspect of the present invention, there is provided a gain adjustment apparatus for an audio encoder, comprising:

a clipping detection module, configured to perform clipping detection on a digital audio signal output by the audio encoder;

a clipping counting module, configured to calculate, according to the detection result of the clipping detection, a number of sampling points where the digital audio signal is clipped; and

And a gain adjustment module, configured to reduce an amplification gain of the audio encoder if the number of sampling points is greater than a set value.

Optionally, the gain adjustment device further includes:

a connection detecting module, configured to detect whether the audio source device is connected to the analog audio signal input interface of the audio encoder, and if yes, notify the gain adjustment module to set the amplification gain of the audio encoder to be equal to a default value, and then notify The clipping detection module performs the clipping detection.

Optionally, the gain adjustment device further includes a connection detection module and a disconnection detection module;

The connection detecting module is configured to detect whether an audio source device is connected to an analog audio signal input interface of the audio encoder, and if yes, notify the disconnection detecting module to detect whether the audio source device is disconnected from the analog audio The signal input interface is connected, and the clipping detection module is notified to perform the clipping detection.

The disconnection detecting module is configured to set an amplification gain of the audio encoder to be equal to a default value according to a detection result that the audio source device disconnects the connection with the analog audio signal input interface.

Optionally, the clipping detection module includes:

a reading unit for reading a value of a sampling point of the digital audio signal; and

And a marking unit, configured to mark the sampling point to be clipped if the value is greater than or equal to a preset clipping signal reference value.

Optionally, the clip counting module is configured to calculate a number of sampling points of the continuously occurring clipping of the digital audio signal, wherein the continuously occurring clipping is set to be an adjacent sampling point where clipping occurs. The number of sampling points between the intervals is less than or equal to the preset value; or,

The clip count module is configured to calculate a continuous number of each set number of the digital audio signal The number of sample points where clipping occurred in the sample point.

According to a third aspect of the present invention, there is also provided a gain adjustment apparatus for an audio encoder, comprising a memory and a processor, the memory for storing an instruction for controlling the processor to operate To implement the gain adjustment method according to the first aspect of the invention.

According to a fourth aspect of the invention, there is also provided an audio encoder comprising the gain adjustment device according to the second or third aspect of the invention.

According to a fifth aspect of the invention, there is also provided an audio apparatus comprising the audio encoder according to the fourth aspect of the invention.

An advantageous effect of the present invention is that the gain adjustment method and apparatus for an audio encoder of the present invention adaptively reduces the amplification gain of the audio encoder based on the detection result of the clipping detection of the converted digital audio signal, Provides the highest amplification gain within the maximum conversion range supported by the analog-to-digital conversion module, thereby maximizing the maximum output power of the audio equipment and achieving effective performance of the acoustic performance.

Other features and advantages of the present invention will become apparent from the Detailed Description of the <RTIgt;

DRAWINGS

The accompanying drawings, which are incorporated in FIG

1 is a schematic flow chart of a gain adjustment method according to an embodiment of the present invention;

2 is a schematic flow chart of a gain adjustment method according to another embodiment of the present invention;

3 is a schematic flow chart of a gain adjustment method according to a third embodiment of the present invention;

4 is a flow chart showing a specific example of a gain adjustment method according to the present invention;

FIG. 5 is a schematic block diagram of a gain adjustment apparatus according to an embodiment of the present invention; FIG.

6 is a schematic block diagram of a gain adjustment apparatus according to another embodiment of the present invention;

FIG. 7 is a schematic block diagram of a gain adjustment apparatus according to a third embodiment of the present invention; FIG.

Figure 8 is a block schematic diagram showing a hardware configuration of a gain adjusting device according to the present invention;

9 is a schematic block diagram of an audio encoder in accordance with an embodiment of the present invention;

Figure 10 is a schematic block diagram of an audio device in accordance with an embodiment of the present invention.

detailed description

Various exemplary embodiments of the present invention will now be described in detail with reference to the drawings. It should be noted that the relative arrangement of the components and steps, numerical expressions and numerical values set forth in the embodiments are not intended to limit the scope of the invention unless otherwise specified.

The following description of the at least one exemplary embodiment is merely illustrative and is in no way

Techniques, methods and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail, but the techniques, methods and apparatus should be considered as part of the specification, where appropriate.

In all of the examples shown and discussed herein, any specific values are to be construed as illustrative only and not as a limitation. Thus, other examples of the exemplary embodiments may have different values.

It should be noted that similar reference numerals and letters indicate similar items in the following figures, and therefore, once an item is defined in one figure, it is not required to be further discussed in the subsequent figures.

<method>

1 is a flow chart showing a gain adjustment method for performing a gain adjustment according to an embodiment of the present invention.

According to FIG. 1, the step of performing gain adjustment by the gain adjustment method of the present invention includes:

Step S110, performing clipping detection on the digital audio signal output by the audio encoder.

The audio encoder comprises a signal shaping module, an amplification module and an analog to digital conversion module. According to the gain adjustment method of the present invention, the amplification module is a gain adjustable amplification module.

The gain adjustable amplification module can include a programmable gain amplifier to support gain adjustment in accordance with the gain adjustment method of the present invention.

The digital audio signal is the output of an analog to digital conversion module of the audio encoder.

The performing clipping detection on the digital audio signal output by the audio encoder in the step S110 may further include:

Step S111, reading the value of the sampling point of the digital audio signal.

This step S111 may be to read the sample point value of the digital audio signal in chronological order.

The digital audio signal output by the analog to digital conversion module can be stored in the signal buffer, and the value of the sampling point of the digital audio signal can be further read from the signal buffer of the analog to digital conversion module at step S111.

The digital audio signal output by the analog to digital conversion module can be stored in the signal buffer on a first in, first out basis.

The step S111 can further read the value of the sampling point of the digital audio signal from the signal buffer of the analog-to-digital conversion module according to the principle of first in first out.

Step S112, determining whether the read value is greater than or equal to a preset clipping signal reference value, and if so, the flag is clipped at the sampling point, and if not, determining that the sampling point is not clipped.

Clipping occurs because the audio encoder allows the input analog audio signal to typically have a dynamic range that is greater than the maximum convertible range of the analog-to-digital conversion module. The maximum convertible range of the analog-to-digital conversion module is 0-2.1Vrms, but the input analog audio signal can reach 5V as an example. If the analog audio signal input to the analog-to-digital conversion module reaches 2.1Vrms or more, the analog-to-digital conversion module The output digital audio signal in PCM format is usually 0dBFS. Therefore, the clipped signal reference value can be set equal to the output value of the analog to digital conversion module when receiving an analog audio signal that is greater than its maximum convertible range.

Step S120, calculating the number of sampling points at which the digital audio signal is clipped based on the detection result of the clipping detection.

In the process of performing the gain adjustment, the number of sampling points in which the clipping occurs in the step S120 can be cumulatively counted according to the detection result until the end of the first gain adjustment.

In order to improve the accuracy of the gain adjustment according to the clipping detection result, the number of sampling points for calculating the clipping of the digital audio signal in the step S120 may further be: calculating the digital audio signal according to the detection result of the clipping detection. The number of sampling points where clipping occurs continuously.

The continuous occurrence of clipping can be set to be such that the number of sampling points between adjacent sampling points where clipping occurs is less than or equal to a preset value.

This preset value can be equal to zero. This means that after detecting that the nth sample point is clipped, only the (n+1)th sample point is clipped, and the cumulative number of sample points is counted. Otherwise, the next time the clip is detected. The sampling point is restarted after the sampling point.

In order to improve the fault tolerance of the clipping detection calculation, the preset value may also be greater than or equal to one. Taking the preset value as 10 as an example, this means that after detecting that the nth sample point is clipped, if the mth sample point is detected, it is also clipped, and the number of samples between m and n is less than or If it is equal to 10, the cumulative counting of the number of sampling points will be performed. Otherwise, the number of sampling points will be recalculated starting from the mth sampling point.

In order to improve the accuracy of the gain adjustment according to the clipping detection result, the number of sampling points for calculating the clipping of the digital audio signal in the step S120 may further be: calculating the digital audio signal according to the detection result of the clipping detection. The number of sample points where clipping occurs in each consecutive number of sample points.

Taking 100 sets as an example, each consecutive 100 sample points of the digital audio signal can be grouped into one group, and the number of sample points in the group where clipping occurs is cumulatively calculated.

According to the above step S112, in this step S120, the number of sampling points at which clipping is generated can be calculated based on the flagged condition of the numerical value of the digital audio signal.

In this step S120, the clip count value i can be set, and the initial value of the clip count value i at the start of the first gain adjustment is set to be equal to 0, in order to achieve the above-mentioned clipping, continuous clipping or each setting The calculation of the number of sampling points where clipping occurs in a continuous number of consecutive sampling points (hereinafter collectively referred to as the number of sampling points indicating clipping).

After starting the gain adjustment, the clipping count value can be incremented by 1 every time a sampling point where clipping occurs is detected according to step S110, so that the clipping count value can reflect the number of sampling points where clipping occurs. It is also possible to further clear the clipping count value under the condition that the continuous occurrence of clipping is not satisfied, so that the clipping count value reflects the number of sampling points in which clipping is continuously performed. It is also possible to further clear the clipping count value each time a set number of sampling points are detected, so that the clipping count value reflects the number of sampling points in each successive number of consecutive sampling points. Step S130, determining whether the number of sampling points calculated in step S120 is greater than a set value, and if so, reducing the amplification gain of the audio encoder, completing one gain adjustment, and if not, returning to step S110 to continue the clipping detection.

The set value can take into account the clipping suppression response time, the sampling rate of the analog-to-digital conversion module, the clipping range, and the recognition range of the human ear to the sound.

An example of selecting a set value is provided below without limitation.

Set the lower limit of the value: the average human ear is sensitive to sounds of around 3 to 5 kHz. For example, the 4KHz sine wave will be clipped above 0.9 times the peak value and the sampling rate is 48KHz. The number of sampling points corresponding to the clipped region is N1:

N1=(Arcsin(1)-arcsin(0.9))×2/360°×(1/4K×48KHz)≈2

Here, since high-frequency noise may exist on the signal line, in order to prevent the clipping detection from being erroneously triggered, it is possible to collect, for example, five sine waves to be clipped as the minimum value of the set value, that is, to set the value. The lower limit can be chosen to be 10.

Setting the upper limit of the value: The average human ear is audible to the sound of 20 Hz to 20 kHz. Taking a 20 Hz sine wave clipped above 0.9 times the peak value and a sampling rate of 48 kHz as an example, the number of sampling points corresponding to the clipped region N2 is:

N2=(Arcsin(1)-arcsin(0.9))×2/360°×(1/20×48KHz)≈400

When the sampling rate is 48KHz, it takes about 8ms to generate 400 sampling points. In order to minimize the clipping suppression response time (proportional to the set value), you can select the number of sampling points required for clipping distortion to be 2ms. The upper limit of the value is determined, so the upper limit can be selected to be 100. The number of settings above can be slightly larger than the selected setting value. For example, it can overflow 10% with respect to the set value. For example, if the set value is 100, the number of settings may be 110.

In this step S130, reducing the amplification gain of the audio encoder may further reduce the amplification gain of the audio encoder by a set fixed step.

The fixed step size can be determined according to the gain adjustment range of the audio encoder, the dynamic range of the input analog audio signal, and the like.

In embodiments where the gain adjustment range is -12 dB to +12 dB, the fixed step distance can be set, for example, from 0.5 dB to 2 dB.

After the gain adjustment is completed according to step S130, the next gain adjustment may be performed according to the above steps S110 to S130.

When the next gain adjustment is started, the above clipping count value will be cleared to start calculating the sampling point indicating clipping according to the continuation detection result (ie, the detection result of the next gain adjustment) when the next gain adjustment is performed. Quantity. Taking the gain adjustment at time t1 as an example, when the next gain adjustment is performed, the number of sampling points indicating clipping will be calculated based on the detection result of the digital audio signal at the time after t1, until the sampling point indicating clipping is performed. The number is greater than the setting The next gain adjustment is completed up to the value.

2 is a flow chart showing a gain adjustment method for performing a gain adjustment according to another embodiment of the present invention.

According to FIG. 2, the embodiment shown in FIG. 2 is mainly related to the embodiment shown in FIG. 1, and the following steps are mainly added:

Step S210: It is detected whether the audio source device is connected to the analog audio signal input interface of the audio encoder, and if yes, step S220 is performed, and if no, step S210 is continued.

The analog audio signal input interface is an interface of the audio encoder for connecting to an audio source device, such as a mobile handset such as a mobile phone, a CD player, an AV decoder, and the like.

The audio encoder may have an analog audio signal input interface or more than two (including two) analog audio signal input interfaces depending on the adapted audio source device type.

The analog audio signal input interface has pins for the audio encoder to detect if an audio source device is connected.

In step S220, the amplification gain of the audio encoder is first set to be equal to the default value, and then the above steps S110 to S130 are performed.

According to the above steps S110 to S130, the gain adjustment method of the present invention performs the adjustment adjustment of the amplification gain when performing the gain adjustment, so that when the input analog audio signal has the characteristics of large dynamic range and fast transient change, A problem that causes a large increase in the distortion of the digital audio signal. This means that the default value is the maximum value of the amplification gain of the audio encoder.

This default value can be set equal to the upper limit of the amplification gain allowed by the audio encoder.

In an embodiment in combination with setting the clip count value, the gain adjustment method of the present invention may further clear the clip count value after detecting that the audio source device is connected to the analog audio signal input interface and before performing step S110 above. A calculation is performed to calculate the number of sampling points indicating clipping based on the detection result of the upcoming clipping detection.

3 is a flow chart showing a gain adjustment method according to a third embodiment of the present invention.

According to FIG. 3, the embodiment shown in FIG. 3 is mainly related to the embodiment shown in FIG. 1, and the following steps are mainly added:

Step S310, detecting whether the audio source device is connected to the analog audio signal input interface of the audio encoder, and if yes, performing step S320 and step S110 described above, and if not, continuing to execute Step S310.

In step S320, it is detected whether the audio source device disconnects the connection with the analog audio signal input interface. If yes, step S330 is performed, and if no, step S320 is continued.

This step S320 may be performed in parallel with steps S110 to S130 shown in FIG. 1, or may be performed before or after any step.

In step S330, the amplification gain of the audio encoder is set to be equal to the default value.

In the embodiment in combination with setting the clipping count value, the gain adjustment method of the present invention can also clear the clipping count value after detecting that the audio source device is disconnected from the analog audio signal input interface, so as to achieve The detection result of the clipping detection performed by connecting the audio source device again calculates the number of sampling points indicating clipping.

<example>

4 is a flow chart showing a specific example of a gain adjustment method according to the present invention, which corresponds to the above detection result based on the above-described clipping detection, and calculates a cut in each successive number of sets of the digital audio signal. An example of the number of sampling points of a wave.

According to FIG. 4, the gain adjustment method of the present invention may include two threads.

The thread on the left side in FIG. 4 executes steps S411 to S420 in FIG. 4, and the thread on the right side performs steps S421 to S422 in FIG.

Step S411, detecting whether the audio source device is connected to the analog audio signal input interface of the audio encoder, if yes, executing step S412 and step S421, and if not, proceeding to step S411.

In step S412, the amplification gain of the audio encoder is set to be equal to the default value, and then step S413 is performed.

In step S413, the clip count value i=0 is set, the sample point count value j=1, and then step S414 is performed.

Step S414, detecting whether the jth sampling point of the digital audio signal output by the audio encoder is clipped, if yes, executing step S415, and if not, executing step S419.

In step S415, it is determined whether j is less than or equal to the set number. If yes, step S416 is performed, and if no, step S420 is performed.

In step S416, the clip count value i=i+1 is set, and then step S417 is performed.

In step S417, it is determined whether the clip count value is greater than the set value. If yes, step S418 is performed, and if no, step S419 is performed.

Step S418, reducing the amplification gain of the audio encoder, and then returning to step S413.

In step S419, j=j+1 is set, and then step S414 is performed.

In step S420, j=1 is set, and then step S414 is performed.

Through step S420, the sampling point count is re-started from the next sampling point.

Step S421, detecting whether the audio source device disconnects the connection with the analog audio signal input interface, and if yes, executing step S422; if not, proceeding to step S421.

Step S422, setting the amplification gain of the audio encoder to be equal to the default value, and setting the clipping count value i=0.

<device>

Figure 5 is a schematic block diagram of a gain adjustment apparatus in accordance with an embodiment of the present invention.

According to FIG. 5, the gain adjustment apparatus of the present invention includes a clipping detection module 510, a clipping counter module 520, and a gain adjustment module 530.

The clipping detection module 510 is configured to perform clipping detection on the digital audio signal output by the audio encoder.

The clipping detection module 510 can further include a reading unit and a marking unit (not shown). The reading unit is configured to read a value of a sampling point of the digital audio signal; the marking unit is configured to: when the value is greater than or equal to a preset clipping signal reference value, the marking is clipped at the sampling point .

The clipping counting module 520 is configured to calculate the number of times of clipping of the digital audio signal by the detection result of the clipping detection by the clipping detecting module 510.

The clipping counting module 520 can be further configured to calculate a number of times of clipping of the digital audio signal continuously occurring according to the detection result of the clipping detection by the clipping detecting module 510, where the continuous occurrence of clipping is set to be The number of sampling points between adjacent sampling points where clipping occurs is less than or equal to a preset value.

The clipping counter module 520 can also be further configured to calculate each of the digital audio signals The number of sampling points where clipping occurs in a continuous number of consecutive sampling points.

The clip count module 520 can represent the calculated number of sample points by setting a clip count value.

The gain adjustment module 530 is configured to reduce the amplification gain of the audio encoder if the number of sample points calculated by the clipping counter module 520 is greater than a set value.

After completing the gain adjustment, the gain adjustment module 530 will notify the clipping counting module 520 to start calculating the number of sampling points indicating clipping according to the detection result of the clipping detection that the clipping detection module 510 continues.

Further, for the embodiment of the clipping count module 520 to set the clipping count value, the gain adjustment module 530 will notify the clipping counter module 520 to clear the clipping count value after completing one gain adjustment.

The gain adjustment module 530 can be specifically configured to reduce the amplification gain of the audio encoder by a set fixed step.

FIG. 6 is a schematic block diagram of a gain adjustment apparatus according to another embodiment of the present invention.

According to FIG. 6, the main difference between this embodiment and the embodiment shown in FIG. 5 is that the gain adjustment device further includes a connection detecting module 610.

The connection detecting module 610 is configured to detect whether the audio source device is connected to the analog audio signal input interface of the audio encoder, and if yes, notify the above gain adjusting module 530 to set the amplification gain of the audio encoder to be equal to the default value, and then notify the clipping detection. Module 510 performs clipping detection.

Further, the connection detecting module 610 is further configured to notify the clipping counting module 520 according to the clipping detection after detecting that the audio source device is connected to the analog audio signal input interface, and before informing the clipping detecting module 510 to perform clipping detection. The detection result of the clipping detection to be performed by the module 510 starts to calculate the number of sampling points indicating clipping.

Further, for the embodiment of the clipping count module 520 to set the clipping count value, the connection detecting module 610 can also be configured to notify the clipping detecting module 510 after detecting that the audio source device is connected to the analog audio signal input interface. Before the clipping detection is performed, the clipping count module 520 is notified to clear the clipping count value.

Figure 7 is a functional block diagram of a gain adjustment apparatus in accordance with a third embodiment of the present invention.

According to FIG. 7, the main difference between this embodiment and the embodiment shown in FIG. 5 is that the gain is The adjustment device also includes a connection detection module 710 and a disconnection detection module 720.

The connection detecting module 710 is configured to detect whether the audio source device is connected to the analog audio signal input interface of the audio encoder, and if so, notify the disconnection detecting module 710 whether the audio source device disconnects from the analog audio signal input interface. .

The disconnection detecting module 720 is configured to set an amplification gain of the audio encoder to be equal to a default value according to a detection result that the audio source device disconnects the connection with the analog audio signal input interface.

Further, the disconnection detecting module 720 is further configured to notify the clipping counting module 520 to perform clipping according to the clipping detecting module 510 according to the detection result that the audio source device disconnects the connection with the analog audio signal input interface. The detected test results begin to calculate the number of sample points that represent clipping.

Further, for the embodiment of the clip count module 520 to set the clip count value, the disconnection detection module 720 can also be configured to notify according to the detection result that the audio source device disconnects the connection with the analog audio signal input interface. Clip count module 520 clears the clipping count value.

<Hardware Configuration>

8 is a functional block diagram of a hardware configuration of a gain adjustment apparatus according to an embodiment of the present invention.

According to FIG. 8, the gain adjustment apparatus of the present invention can include at least one memory 810 and at least one processor 820 for storing instructions for controlling the processor 820 to operate to perform gain adjustment in accordance with the present invention. Device.

The memory 810 can include high speed random access memory and can also include non-volatile memory such as one or more magnetic storage devices, flash memory, or other non-volatile solid state memory.

<audio encoder>

9 is a functional block diagram of an audio encoder in accordance with an embodiment of the present invention.

According to FIG. 9, the audio encoder includes a gain-adjustable amplification module 920 and any of the above-described gain adjustment devices 940 in addition to the signal shaping module 910 and the analog-to-digital conversion module 930.

The gain adjustment device 940 performs a reduction adjustment of the amplification gain of the amplification module 920 by performing clipping detection on the digital audio signal output from the analog-to-digital conversion module 930.

The gain adjustable amplification module can include a programmable gain amplifier to support adaptive gain adjustment by gain adjustment device 940.

The audio encoder can also include at least one analog audio signal input interface.

<Audio equipment>

Figure 10 is a schematic block diagram of an audio device in accordance with an embodiment of the present invention.

According to FIG. 10, the audio device includes the audio encoder 1010 of FIG. 9, and further includes a power amplifier 1020 and a speaker 1030.

The digital audio signal output by the audio encoder 1010 is output to a power amplifier 1020 (digital power amplifier) to drive the speaker 1030 to sound through the power amplifier 1020.

The various embodiments in the present specification are described in a progressive manner, and the same or similar parts between the various embodiments may be referred to each other, and each embodiment focuses on the differences from other embodiments, but the field It should be clear to the skilled person that the above embodiments can be used individually or in combination with each other as needed. In addition, for the device embodiment, since it corresponds to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the description of the corresponding part of the method embodiment. The device embodiments described above are merely illustrative, and the modules illustrated as separate components may or may not be physically separate.

The invention can be an apparatus, method and/or computer program product. The computer program product can comprise a computer readable storage medium having computer readable program instructions embodied thereon for causing a processor to implement various aspects of the present invention.

The computer readable storage medium can be a tangible device that can hold and store the instructions used by the instruction execution device. The computer readable storage medium can be, for example, but not limited to, an electrical storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. More specific examples (non-exhaustive list) of computer readable storage media include: portable computer disks, hard disks, random access memory (RAM), read only memory (ROM), erasable programmable read only memory (EPROM) Or flash memory), static random access memory (SRAM), portable compact disk read only memory (CD-ROM), digital versatile disk (DVD), memory stick, floppy disk, mechanical encoding device, for example, with instructions stored thereon A raised structure in the hole card or groove, and any suitable combination of the above. The meter used here A computer readable storage medium is not to be interpreted as a transient signal itself, such as a radio wave or other freely propagating electromagnetic wave, an electromagnetic wave propagating through a waveguide or other transmission medium (eg, a light pulse through a fiber optic cable), or an electrical transmission through a wire signal.

The computer readable program instructions described herein can be downloaded from a computer readable storage medium to various computing/processing devices or downloaded to an external computer or external storage device over a network, such as the Internet, a local area network, a wide area network, and/or a wireless network. The network may include copper transmission cables, fiber optic transmissions, wireless transmissions, routers, firewalls, switches, gateway computers, and/or edge servers. A network adapter card or network interface in each computing/processing device receives computer readable program instructions from the network and forwards the computer readable program instructions for storage in a computer readable storage medium in each computing/processing device .

Computer program instructions for performing the operations of the present invention may be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine related instructions, microcode, firmware instructions, state setting data, or in one or more programming languages. Source code or object code written in any combination, including object oriented programming languages such as Smalltalk, C++, etc., as well as conventional procedural programming languages such as the "C" language or similar programming languages. The computer readable program instructions can execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer, partly on the remote computer, or entirely on the remote computer or server. carried out. In the case of a remote computer, the remote computer can be connected to the user's computer through any kind of network, including a local area network (LAN) or wide area network (WAN), or can be connected to an external computer (eg, using an Internet service provider to access the Internet) connection). In some embodiments, the customized electronic circuit, such as a programmable logic circuit, a field programmable gate array (FPGA), or a programmable logic array (PLA), can be customized by utilizing state information of computer readable program instructions. Computer readable program instructions are executed to implement various aspects of the present invention.

Aspects of the present invention are described herein with reference to flowchart illustrations and/or block diagrams of methods, apparatus, and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowcharts and/or block diagrams can be implemented by computer readable program instructions.

These computer readable program instructions can be provided to a general purpose computer, a special purpose computer or the like Programmable processor of the data processing apparatus to produce a machine that, when executed by a processor of a computer or other programmable data processing apparatus, produces one or more of an implementation flow diagram and/or block diagram The function/action device specified in the box. The computer readable program instructions can also be stored in a computer readable storage medium that causes the computer, programmable data processing device, and/or other device to operate in a particular manner, such that the computer readable medium storing the instructions includes An article of manufacture that includes instructions for implementing various aspects of the functions/acts recited in one or more of the flowcharts.

The computer readable program instructions can also be loaded onto a computer, other programmable data processing device, or other device to perform a series of operational steps on a computer, other programmable data processing device or other device to produce a computer-implemented process. Thus, instructions executed on a computer, other programmable data processing apparatus, or other device implement the functions/acts recited in one or more of the flowcharts and/or block diagrams.

The flowchart and block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of apparatus, methods, and computer program products according to various embodiments of the invention. In this regard, each block in the flowchart or block diagram can represent a module, a program segment, or a portion of an instruction that includes one or more components for implementing the specified logical functions. Executable instructions. In some alternative implementations, the functions noted in the blocks may also occur in a different order than those illustrated in the drawings. For example, two consecutive blocks may be executed substantially in parallel, and they may sometimes be executed in the reverse order, depending upon the functionality involved. It is also noted that each block of the block diagrams and/or flowcharts, and combinations of blocks in the block diagrams and/or flowcharts, can be implemented in a dedicated hardware-based system that performs the specified function or function. Or it can be implemented by a combination of dedicated hardware and computer instructions. It is well known to those skilled in the art that implementation by hardware, implementation by software, and implementation by a combination of software and hardware are equivalent.

The embodiments of the present invention have been described above, and the foregoing description is illustrative, not limiting, and not limited to the disclosed embodiments. Numerous modifications and changes will be apparent to those skilled in the art without departing from the scope of the invention. The choice of terms used herein is intended to best explain the principles, practical applications, or technical improvements of the techniques in the various embodiments, or to enable those of ordinary skill in the art to understand the disclosure herein. Various embodiments. The scope of the invention is defined by the appended claims.

Claims (14)

1. A gain adjustment method for an audio encoder, comprising:

   Performing clipping detection on the digital audio signal output by the audio encoder;

   Calculating a number of sampling points of the digital audio signal that are clipped according to the detection result of the clipping detection;

   If the number of sampling points is greater than a set value, the amplification gain of the audio encoder is reduced.
2. The gain adjustment method according to claim 1, wherein the method further comprises:

   Detecting whether the audio source device is connected to the analog audio signal input interface of the audio encoder, if yes, first setting the amplification gain of the audio encoder to be equal to a default value, and then starting to cut the digital audio signal output by the audio encoder Wave detection.
3. The gain adjustment method according to claim 1 or 2, wherein the method further comprises:

   Detecting whether the audio source device is connected to the analog audio signal input interface of the audio encoder, such as:

   And then start to perform clipping detection on the digital audio signal output by the audio encoder; and

   Detecting whether the audio source device disconnects from the analog audio signal input interface, and if so, setting the amplification gain of the audio encoder to be equal to a default value.
4. The gain adjustment method according to any one of claims 1 to 3, wherein the reducing the amplification gain of the audio encoder comprises:

   The amplification gain of the audio encoder is reduced by a set fixed step.
5. The gain adjustment method according to any one of claims 1 to 4, wherein the clipping detection of the digital audio signal output by the audio encoder comprises:

   Reading the value of the sampling point of the digital audio signal;

   If the value is greater than or equal to the preset clipping signal reference value, then the sampling point is marked as being clipped.
6. The gain adjustment method according to any one of claims 1 to 5, wherein the calculating the number of sampling points at which the digital audio signal is clipped comprises:

   Calculating a number of sampling points of the continuously occurring clipping of the digital audio signal, wherein the continuously occurring clipping is set to be a sampling point interval between adjacent sampling points where clipping occurs is less than or equal to a preset value; or,

   The calculating the number of sampling points where the digital audio signal is clipped includes:

   The number of sample points where clipping occurs in each successive number of sets of the digital audio signal is calculated.
7. A gain adjustment apparatus for an audio encoder, comprising:

   a clipping detection module, configured to perform clipping detection on a digital audio signal output by the audio encoder;

   a clipping counting module, configured to calculate, according to the detection result of the clipping detection, a number of sampling points where the digital audio signal is clipped; and

   And a gain adjustment module, configured to reduce an amplification gain of the audio encoder if the number of sampling points is greater than a set value.
8. The gain adjustment device according to claim 7, wherein the gain adjustment device further comprises:

   a connection detecting module, configured to detect whether the audio source device is connected to the analog audio signal input interface of the audio encoder, and if yes, notify the gain adjustment module to set the amplification gain of the audio encoder to be equal to a default value, and then notify The clipping detection module performs the clipping detection.
9. The gain adjustment device according to claim 7 or 8, wherein the gain adjustment device further comprises a connection detection module and a disconnection detection module;

   The connection detecting module is configured to detect whether an audio source device is connected to an analog audio signal input interface of the audio encoder, and if yes, notify the disconnection detecting module to detect whether the audio source device is disconnected from the analog audio The signal input interface is connected, and the clipping detection module is notified to perform the clipping detection.

   The disconnection detecting module is configured to set an amplification gain of the audio encoder to be equal to a default value according to a detection result that the audio source device disconnects the connection with the analog audio signal input interface.
10. The gain adjustment apparatus according to any one of claims 7 to 9, wherein the clipping detection module comprises:

    a reading unit for reading a value of a sampling point of the digital audio signal; and

    And a marking unit, configured to mark the sampling point to be clipped if the value is greater than or equal to a preset clipping signal reference value.
11. The gain adjustment apparatus according to any one of claims 7 to 10, wherein the clip count module is configured to calculate a number of sampling points in which the digital audio signal is continuously clipped, wherein the continuous The occurrence of clipping is set such that the number of sampling points between adjacent sampling points where clipping occurs is less than or equal to a preset value; or

    The clip count module is configured to calculate a number of sample points that are clipped in each consecutive number of sample points of the digital audio signal.
12. A gain adjustment apparatus for an audio encoder, comprising: a memory and a processor, the memory for storing instructions for controlling the processor to operate to perform according to claims 1 to 6 The gain adjustment method according to any one of the preceding claims.
13. An audio encoder comprising the gain adjustment device of any one of claims 7 to 12.
14. An acoustic device comprising the audio encoder of claim 13.

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