Sine wave audio processing method and processing terminal

Abstract

A sine wave audio processing method, comprising the following steps: step 1, segmenting a received audio signal to obtain a plurality of sub-audio signals, and determining the number of sampling points of each sub-audio signal; step 2, traversing all the sub-audio signals, on the basis of the amplitude of each sub-audio signal, determining whether clipping is present in a current sub-audio signal, and denoting as a clipped audio frame an audio signal having the clipping; step 3, traversing all the sub-audio signals, and determining a clipping start position and a clipping end position in the audio signal, so as to determine all clipping positions in the audio signal; and step 4, generating a standard sine wave audio signal model, the amplitude of each clipping from the clipping start position to the clipping end position in the audio signal being the amplitude of the standard sine wave audio signal model at a corresponding position, so as to restore the clipping of the audio signal and complete audio processing. The present invention can restore original forms of audio signals, thereby maintaining the original sound quality in terms of purity and naturalness as much as possible.

Description

A sine wave audio processing method and processing terminal TECHNICAL FIELD

[0001] The present application relates to the technical field of computers, and particularly relates to a sine wave audio processing method and processing terminal. BACKGROUND

[0002] In the process of audio transmission, the audio signal is generally preprocessed on a hardware circuit, including using a compressor or a limiter and the like to process the audio signal before entering an amplifier, so as to reduce the dynamic range of the audio signal with an excessively large amplitude and prevent the audio signal from being overloaded. Such a circuit device reduces the dynamic range by reducing the peak amplitude of the audio signal, thereby avoiding clipping of the audio signal.

[0003] However, the existing processing technology for processing the clipped audio signal has some defects and deficiencies.

[0004] 1. Additional distortion is introduced. In the compression process of the compressor and the limiting process of the limiter, the dynamic range of the audio signal may be reduced, and part of the details of the original audio signal is lost.

[0005] 2. The compressor or the limiter and the like need to be added, which increases the complexity and cost of the hardware circuit and weakens the market competitiveness of the product.

[0006] 3. For the audio signal that is severely clipped, the hardware processing scheme based on the hardware circuit may not completely restore the original audio quality, especially in the case where the audio signal has been severely damaged.

[0007] In summary, an audio processing method that can better restore the clipped audio signal is needed. SUMMARY

[0008] In view of the deficiencies of the prior art, the present application aims to provide a sine wave audio processing method and processing terminal, which can solve the problems described in the background art.

[0009] The technical scheme for achieving the purpose of the present application is as follows: a sine wave audio processing method, comprising the following steps:

[0010] Step 1: dividing the received audio signal to obtain a plurality of sub-audio signals, and determining the number of sampling points of each sub-audio signal;

[0011] Step 2: traversing all the sub-audio signals, judging whether the current sub-audio signal exists clipping based on the amplitude of the sub-audio signal, and recording the audio signal with clipping as a clipped audio frame;

[0012] Step 3: Traverse all the sub-audio signals to determine the clipping start position and end position of the audio signal, thereby determining all the clipping positions of the audio signal;

[0013] Step 4: Generate a standard sinusoidal wave audio signal model, and the amplitude of each clipping of the audio signal from the clipping start position to the clipping end position is the amplitude at the corresponding position of the standard sinusoidal wave audio signal model, thereby restoring the clipping of the audio signal and completing the audio processing.

[0014] Further, the audio signal is cut according to a preset time interval, and the number of sample points of each sub-audio signal is determined based on the sampling frequency and the preset time interval.

[0015] Further, the current sub-audio signal is determined to have clipping based on the amplitude of the sub-audio signal, and the specific implementation process includes the following steps:

[0016] Step 21: Calculate the audio amplitude corresponding to each sample point, and the audio amplitude of the nth sample point is denoted as x(n). The average amplitude of the current sub-audio signal is calculated according to formula ① :

[0017] ------②

[0018] In the formula, N represents the total number of sub-audio signals;

[0019] Step 22: Compare the audio amplitudes of each sample point to find the maximum audio amplitude, and the maximum audio amplitude is denoted as ;

[0020] Step 23: Compare the size of and , if the size relationship meets condition one, the current sub-audio signal has clipping,

[0021] Condition one: , D>0, and D is a preset value.

[0022] Further, the audio signal is cut according to a preset time interval, and the number of sample points of each sub-audio signal is determined based on the sampling frequency and the preset time interval.

[0023] Step 31: for the current sub-audio signal, starting from any one of the clip top frames, traversing each sample point backward, finding the first sample point with clip top, the first sample point with clip top being the clip top start position of the current sub-audio signal; traversing each sample point forward, finding the last sample point with clip top, the last sample point with clip top being the clip top end position of the current sub-audio signal, thereby obtaining the clip top start position and the clip top end position of the current sub-audio signal;

[0024] Step 32: traversing each sub-audio signal, thereby determining the clip top start position and the clip top end position of each sub-audio signal, the clip top start position of the audio signal being the clip top start position of the first sub-audio signal, and the clip top end position of the audio signal being the clip top end position of the last sub-audio signal.

[0025] Further, based on the un-clip top audio signal or the known reference audio signal, the sinusoidal wave parameters of the audio signal are extracted, the sinusoidal wave parameters including frequency, amplitude and phase, and the audio signal model of the standard sinusoidal wave is generated based on the sinusoidal wave parameters.

[0026] Further, if the sample point at the clip top position of the audio signal is lost or damaged, interpolation is performed based on the adjacent un-clip top sample points to estimate the lost or damaged sample point through interpolation.

[0027] Further, the interpolation adopts linear interpolation or spline interpolation.

[0028] A processing terminal comprises:

[0029] a memory for storing program instructions;

[0030] a processor for running the program instructions to perform the steps of the sinusoidal wave audio processing method.

[0031] Advantages of the present application: compared with the existing repair technology of changing the overall characteristics of the audio, the sinusoidal wave clip top restoration can restore the original form of the audio signal, and can keep the original purity and naturalness of the sound quality as much as possible. The distortion caused by clip top is effectively reduced, and the listening feeling of the audio is improved. In addition, the details of the clip top part can be restored, and the integrity of the data is preserved. It is particularly important for audio content such as music and voice which have high requirements for details. The algorithm can be automatically executed, does not need to rely on circuit devices, does not need manual intervention, can save a lot of time and human resources when processing a large number of audio files, and can save the additional cost caused by traditional hardware circuit-based circuit devices. BRIEF DESCRIPTION OF DRAWINGS

[0032] Fig. 1 is a flowchart of the present application;

[0033] Fig. 2 is a schematic diagram of the structure of a processing terminal. DETAILED DESCRIPTION

[0034] The application will be further described below in conjunction with the drawings and specific embodiments:

[0035] As shown in Fig. 1, a sine wave audio processing method comprises the following steps:

[0036] Step 1: receiving an audio signal, dividing the audio signal to obtain a plurality of sub-audio signals, and determining the number of sampling points of each sub-audio signal.

[0037] For example, an audio signal with a time length of 1S (second) is received, and is divided into 1 sub-audio signal every 20ms (millisecond), thereby obtaining 50 sub-audio signals in total. Assuming that the sampling frequency is 44.1kHz (kilohertz), then the sampling sample corresponding to each sub-audio signal is 44100 / 0.02=882, that is, each sub-audio signal includes 882 sampling points, and one sampling point is one sampling sample.

[0038] Step 2: traversing all the sub-audio signals, judging whether the current sub-audio signal exists clipping based on the amplitude of the sub-audio signal, and recording the audio signal existing clipping as a clipping audio frame, thereby finding all the sub-audio signals existing clipping.

[0039] The specific implementation process of judging whether the current sub-audio signal exists clipping based on the amplitude of the sub-audio signal comprises the following steps:

[0040] Step 21: calculating the audio amplitude corresponding to each sample point, and recording the audio amplitude of the nth sample point as x(n), and calculating the average amplitude of the current sub-audio signal according to formula ① :

[0041] ------②

[0042] In the formula, N represents the total number of sub-audio signals.

[0043] Step 22: comparing the audio amplitudes of various sample points, finding the audio amplitude with the largest value, and recording the audio amplitude with the largest value as 。

[0044] Step 23: comparing the size of and , if the size relationship meets condition one, then the current sub-audio signal exists clipping,

[0045] Condition one: D>0, D is a preset value.

[0046] Satisfying condition one, that is, the maximum amplitude of the current sub-audio signal (i.e. the peak value) is significantly higher than the average amplitude of the sub-audio signal, which indicates that the current sub-audio signal exists clipping.

[0047] Step 3: traversing all sub-audio signals to determine the clipping start position and end position of the audio signal, thereby determining all clipping positions of the audio signal.

[0048] The traversing all sub-audio signals to determine the clipping start position and end position of the audio signal, thereby determining all clipping positions of the audio signal, the specific implementation process includes the following steps:

[0049] Step 31: for the current sub-audio signal, starting from any clipping frame, traversing each sample point backward to find the first sample point with clipping, that is, to find the first clipping audio frame, the first sample point with clipping as the clipping start position of the current sub-audio signal; traversing each sample point forward to find the last sample point with clipping, that is, to find the last clipping audio frame, the last sample point with clipping as the clipping end position of the current sub-audio signal, thereby obtaining the clipping start position and end position of the current sub-audio signal.

[0050] Step 32: traversing each sub-audio signal to determine the clipping start position and end position of each sub-audio signal, and further determine the clipping start position and end position of the audio signal.

[0051] The clipping start position of the audio signal is also the clipping start position of the first sub-audio signal, and the clipping end position of the audio signal is also the clipping end position of the last sub-audio signal.

[0052] Step 4: based on the unclipped audio signal or the known reference audio signal, extracting the sinusoidal wave parameters of the audio signal, including frequency, amplitude and phase, and generating a standard sinusoidal wave audio signal model based on the sinusoidal wave parameters. Based on the standard sinusoidal wave audio signal model, the amplitude of the clipping of the audio signal is predicted, and the amplitude of each clipping of the audio signal from the clipping start position to the clipping end position is the amplitude at the corresponding position of the standard sinusoidal wave audio signal model, thereby restoring the clipping of the audio signal and completing the audio processing.

[0053] In an optional embodiment, if the sample points of the clipping position of the audio signal are lost or damaged, interpolation is performed based on the adjacent unclipped sample points to estimate the lost or damaged sample points through interpolation.

[0054] In the interpolation, linear interpolation or spline interpolation is adopted. Since linear interpolation and spline interpolation are prior art, details of the interpolation are not described herein.

[0055] Compared with the prior repair technology of changing the overall characteristics of the audio, the sine wave clipping restoration can restore the original form of the audio signal, and can keep the original purity and naturalness of the sound quality as much as possible. The distortion caused by clipping is effectively reduced, and the listening feeling of the audio is improved. In addition, the details of the clipped part can be restored, and the integrity of the data is preserved. It is particularly important for audio content such as music and voice which have high requirements on details,

[0056] The algorithm can be automatically executed without the aid of circuit devices, and does not require manual intervention. When a large number of audio files are processed, a large amount of time and human resources can be saved, and additional costs caused by traditional hardware circuit-based circuit devices can be saved.

[0057] As shown in FIG. 2, the present application further provides a processing terminal 100, which comprises:

[0058] a memory 101 for storing program instructions;

[0059] a processor 102 for running the program instructions to execute the steps of the sine wave audio processing method.

[0060] The embodiments disclosed in the specification are only an example of the one-sided features of the present application, and the protection scope of the present application is not limited to this embodiment. Any other functionally equivalent embodiments fall within the protection scope of the present application. For those skilled in the art, other various corresponding changes and modifications can be made according to the above described technical solutions and concepts, and all these changes and modifications should belong to the protection scope of the claims of the present application.

Claims

1. A method of sinusoidal audio processing, characterized by, The method comprises the following steps: Step 1: segmenting the received audio signal to obtain a plurality of sub-audio signals, and determining the number of sampling points of each sub-audio signal; Step 2: traversing all the sub-audio signals to determine whether the current sub-audio signal has clipping based on the amplitude of the sub-audio signal, and recording the audio signal with clipping as a clipping audio frame; Step 3: traversing all the sub-audio signals to determine the start position and end position of the clipping of the audio signal, thereby determining all the clipping positions of the audio signal; Step 4: generating a standard sinusoidal wave audio signal model, and the amplitude of each clipping of the audio signal from the start position to the end position of the clipping is the amplitude at the corresponding position of the standard sinusoidal wave audio signal model, thereby restoring the clipping of the audio signal and completing the audio processing.

2. The sine wave audio processing method of claim 1, wherein, The audio signal is segmented according to a preset time interval, and the number of sampling points of each sub-audio signal is determined based on the sampling frequency and the preset time interval.

3. The sine wave audio processing method of claim 1, wherein, The determination of whether the current sub-audio signal has clipping based on the amplitude of the sub-audio signal comprises the following steps: Step 21: Calculate the audio amplitude corresponding to each sample point, the audio amplitude of the nth sample point is denoted as x(n), and the average amplitude of the current sub-audio signal is calculated according to formula ① ： ------② In the formula, N represents the total number of sub-audio signals; Step 22: Compare the audio amplitudes of each sample point, find the audio amplitude with the largest value, and mark the audio amplitude with the largest value as ； Step 23: Comparison and If the size relationship meets condition one, the current sub-audio signal has clipping, Condition one: D>0, and D is a preset value.

4. The sine wave audio processing method according to claim 1 or 3, characterized by, The traversal of all the sub-audio signals to determine the start position and end position of the clipping of the audio signal, thereby determining all the clipping positions of the audio signal, comprises the following steps: Step 31: for the current sub-audio signal, starting from any clipping frame, traversing the sample points backward to find the first sample point with clipping, which is taken as the start position of the clipping of the current sub-audio signal; traversing the sample points forward to find the last sample point with clipping, which is taken as the end position of the clipping of the current sub-audio signal, thereby obtaining the start position and end position of the clipping of the current sub-audio signal; Step 32: traversing each sub-audio signal to determine the start position and end position of the clipping of each sub-audio signal, wherein the start position of the clipping of the audio signal is the start position of the clipping of the first sub-audio signal, and the end position of the clipping of the audio signal is the end position of the clipping of the last sub-audio signal.

5. The sine wave audio processing method of claim 4, wherein, Based on the unclipped audio signal or the known reference audio signal, the sinusoidal wave parameters of the audio signal are extracted, including frequency, amplitude and phase, and the standard sinusoidal wave audio signal model is generated based on the sinusoidal wave parameters.

6. The sine wave audio processing method of claim 5, wherein, If the sample points at the clipping positions of the audio signal are lost or damaged, interpolation is performed based on the adjacent unclipped sample points to estimate the lost or damaged sample points through interpolation.

7. The sinusoidal wave audio processing method according to claim 6, wherein, The interpolation adopts linear interpolation or spline interpolation.

8. A processing terminal, characterized by, It comprises: a memory for storing program instructions; a processor for running the program instructions to execute the steps of the sinusoidal wave audio processing method according to any one of claims 1-7.

Images