阅读说明：本技术 用于生猪的音频信号的压缩方法及系统 (Compression method and system for audio signal of live pig ) 是由 吴亚文 何屿彤 焦俊 张双龙 孙裴 辜丽川 张锋 邵睿 李斌 于 2019-11-18 设计创作，主要内容包括：本发明实施方式提供一种用于生猪的音频信号的压缩方法及系统,属于音频信号的压缩传输技术领域。所述压缩方法包括：获取所述音频信号；将所述音频信号转换为数字信号模式；对所述音频信号进行加重处理；对加重处理后的所述音频信号执行归一化操作；对归一化操作后的所述音频信号进行加窗分帧处理；对加窗分帧处理后的所述音频信号进行端点检测以确定所述音频信号的有效信号部分；提取所述有效信号部分以作为预处理后的所述音频信号；采用谱减法压缩预处理后的所述音频信号。该压缩传输方法及系统能够解决现有技术中存在的生猪的音频信号在传输时出现的信息碰撞和拥塞的技术问题。(The embodiment of the invention provides a compression method and a compression system for an audio signal of a live pig, belonging to the technical field of compression and transmission of the audio signal. The compression method comprises the following steps: acquiring the audio signal; converting the audio signal into a digital signal mode; performing emphasis processing on the audio signal; performing a normalization operation on the audio signal after the emphasis processing; performing windowing and framing processing on the audio signal after the normalization operation; performing endpoint detection on the audio signal subjected to windowing and framing processing to determine an effective signal part of the audio signal; extracting the effective signal part as the pre-processed audio signal; compressing the pre-processed audio signal using spectral subtraction. The compression transmission method and the compression transmission system can solve the technical problems of information collision and congestion of the live pig audio signals during transmission in the prior art.)

1. A method of compressing an audio signal for a live pig, the method comprising:

acquiring the audio signal;

converting the audio signal into a digital signal mode;

performing emphasis processing on the audio signal;

performing a normalization operation on the audio signal after the emphasis processing;

performing windowing and framing processing on the audio signal after the normalization operation;

performing endpoint detection on the audio signal subjected to windowing and framing processing to determine an effective signal part of the audio signal;

extracting the effective signal part as the pre-processed audio signal;

compressing the pre-processed audio signal using spectral subtraction.

2. The compression method according to claim 1, wherein the transfer function of the emphasis process is formula (1),

H(z)＝1-αz^-1， (1)

wherein h (z) is the transfer function of the high-pass filter, z is a variation z-domain in the process of processing the audio signal, and α is a pre-emphasis coefficient;

the emphasis processing includes:

the emphasis process is performed according to equation (2),

s(n)＝x(n)-αx(n-1)， (2)

wherein s (n) is the audio signal after the emphasis processing, x (n) is the voice sample value of the audio signal at the time n, and x (n-1) is the voice sample value of the audio signal at the time n-1.

3. The compression method of claim 1, wherein the windowed framing process comprises:

processing the audio signal according to equation (3) and equation (4),

q＝s(n)*w(n)， (3)

wherein q is the audio signal after windowing and framing, s (N) is the audio signal before windowing and framing, w (N) is a hamming window function, and N is the window length of the hamming window function.

4. The compression method of claim 1, wherein the endpoint detection comprises:

determining a valid signal portion of the audio signal according to equations (5) to (6),

wherein E is_nIs the short-time energy of the audio signal, M is the number of frames of the audio signal, q_nFor the audio signalThe nth frame of (1);

wherein Z is_nIs the average zero crossing rate, q, of the audio signal_nIs the nth frame of the audio signal, and M is the frame number of the audio signal.

5. The compression method according to claim 1, wherein the spectral subtraction method comprises:

performing a thinning operation on the audio signal using equations (7) to (13),

y(n)＝q(n)+d(n)， (7)

wherein y (n) is the nth frame of the audio signal with noise Y (n), q (n) is the pure part of the audio signal, d (n) is the nth frame of the noise part of the audio signal D (n);

wherein Y (omega) is a polar coordinate form of the audio signal Y (n) with noise, | Y (omega) | is a corresponding amplitude spectrum,

wherein D (ω) is a polar coordinate form of a noise portion D (n) in the audio signal, | D (ω) | is a corresponding magnitude spectrum,

wherein f (ω) is a polar form of the audio signal, Y (ω) is a polar form of the noisy audio signal Y (n),is an estimate of D (co),

wherein F (k) is the DCT transform of the audio signal f, f (i) is the ith frame of the audio signal f, n is the number of frames of the audio signal f,

F＝α·f， (13)

wherein, F is the audio signal after the sparsification processing, alpha is a standard orthogonal base, and F is the audio signal before the sparsification processing;

constructing an observation matrix of the audio signal according to equation (14) to equation (16) to obtain the compressed audio signal,

M≥cKlog(N/K)＜＜N，(15)

wherein epsilon belongs to (0, 1), theta is a preset measurement matrix of M multiplied by N, F is the audio signal after the sparsification processing, K is the value of the sparsity, alpha is a standard orthogonal base, F is the audio signal before the sparsification processing, A is the observation matrix,

6. A compression system for audio signals, characterized in that the compression system comprises a processor for performing the compression method according to any one of claims 1 to 5.

7. A transmission method of an audio signal for a live pig, the transmission method comprising:

compressing the audio signal using the compression method of any one of claims 1 to 5;

the receiving end receives the audio signal and reconstructs the audio signal by adopting a formula (17) to a formula (21) to obtain the decoded audio signal,

A＝argmin||θ·F||₀s.t.A＝θ·F， (17)

wherein s.t. is a representation-restricted, A is the observation matrix, θ is a measurement matrix, F is the audio signal after the thinning process,

wherein λ is_tThe index found for the t-th iteration, N is the number of elements of the measurement matrix theta, r_t-1The residual error when t is t-1,

8. The transmission method according to claim 7, comprising presetting an audio acquisition system to acquire the audio signal, wherein the audio acquisition system comprises:

the audio acquisition node is arranged on the site and used for acquiring the audio signal;

a first processor for performing the compression method of any one of claims 1 to 5;

communication means for transmitting the compressed audio signal;

a terminal for receiving the audio signal and decoding the audio signal using formula (17) to formula (21).

9. Transmission system for audio signals of live pigs, characterized in that it comprises a processor for carrying out the transmission method according to claim 7 or 8.

10. A storage medium storing instructions for reading by a machine to cause the machine to perform a method according to any one of claims 1 to 5, 7 or 8.

Technical Field

The invention relates to the technical field of compression and transmission of audio signals, in particular to a compression method and a compression system for an audio signal of a live pig.

Background

The sound information of the live pigs can be used as the basis for identifying health, so that the audio information acquisition and transmission of the live pigs based on the multimedia sensor network are the main problems to be solved, and the audio information also reflects the health condition of the live pigs and is an important way for exchanging and expressing emotion. However, in the multimedia WSN, information collision and congestion problems occur during sound transmission, and therefore, the pig audio signal needs to be processed by a compression sensing technology.

Disclosure of Invention

The embodiment of the invention aims to provide a compression method and a compression system for an audio signal of a live pig, and the compression transmission method and the compression transmission system can solve the technical problems of information collision and congestion during transmission of the audio signal of the live pig in the prior art.

In order to achieve the above object, an embodiment of the present invention provides a compression method for an audio signal of a live pig, which may include:

acquiring the audio signal;

converting the audio signal into a digital signal mode;

performing emphasis processing on the audio signal;

performing a normalization operation on the audio signal after the emphasis processing;

performing windowing and framing processing on the audio signal after the normalization operation;

performing endpoint detection on the audio signal subjected to windowing and framing processing to determine an effective signal part of the audio signal;

extracting the effective signal part as the pre-processed audio signal;

compressing the pre-processed audio signal using spectral subtraction.

Optionally, the transfer function of the emphasis process is formula (1),

H(z)＝1-αz^-1， (1)

wherein h (z) is the transfer function of the high-pass filter, z is a variation z-domain in the process of processing the audio signal, and α is a pre-emphasis coefficient;

the emphasis processing includes:

the emphasis process is performed according to equation (2),

s(n)＝x(n)-αx(n-1)， (2)

wherein s (n) is the audio signal after the emphasis processing, x (n) is the voice sample value of the audio signal at the time n, and x (n-1) is the voice sample value of the audio signal at the time n-1.

Optionally, the windowing framing processing includes:

processing the audio signal according to equation (3) and equation (4),

q＝s(n)*w(n)， (3)

wherein q is the audio signal after windowing and framing, s (N) is the audio signal before windowing and framing, w (N) is a hamming window function, and N is the window length of the hamming window function.

Optionally, the endpoint detection comprises:

determining a valid signal portion of the audio signal according to equations (5) to (6),

wherein E is_nIs the short-time energy of the audio signal, M is the number of frames of the audio signal, q_nIs the nth frame of the audio signal;

wherein Z is_nIs the average zero crossing rate, q, of the audio signal_nIs the nth frame of the audio signal, and M is the frame number of the audio signal.

Optionally, the spectral subtraction method comprises:

performing a thinning operation on the audio signal using equations (7) to (13),

y(n)＝q(n)+d(n)， (7)

wherein y (n) is the nth frame of the audio signal with noise Y (n), q (n) is the pure part of the audio signal, d (n) is the nth frame of the noise part of the audio signal D (n);

wherein Y (omega) is a polar coordinate form of the audio signal Y (n) with noise, | Y (omega) | is a corresponding amplitude spectrum,

is the phase spectrum of the audio signal y (n) with noise,

is the phase of the audio signal y (n),

wherein D (ω) is a polar coordinate form of a noise portion D (n) in the audio signal, | D (ω) | is a corresponding magnitude spectrum,

the phase spectrum of the noisy portion d (n),

the phase of the noise portion d (n),

wherein f (ω) is a polar form of the audio signal, Y (ω) is a polar form of the noisy audio signal Y (n),

is an estimate of D (co),

is the phase spectrum of the audio signal y (n) with noise,

is the phase of the audio signal y (n),

wherein F (k) is the DCT transform of the audio signal f, f (i) is the ith frame of the audio signal f, n is the number of frames of the audio signal f,

F＝α·f， (13)

wherein, F is the audio signal after the sparsification processing, alpha is a standard orthogonal base, and F is the audio signal before the sparsification processing;

constructing an observation matrix of the audio signal according to equation (14) to equation (16) to obtain the compressed audio signal,

M≥cKlog(N/K)＜＜N， (15)

wherein epsilon belongs to (0, 1), theta is a preset measurement matrix of M multiplied by N, F is the audio signal after the sparsification processing, K is the value of the sparsity, alpha is a standard orthogonal base, F is the audio signal before the sparsification processing, A is the observation matrix,

is a sensing matrix.

In another aspect, the present invention also provides a compression system for an audio signal, the compression system comprising a processor for performing the compression method as described in any one of the above.

In another aspect, the present invention further provides a transmission method for an audio signal of a live pig, the transmission method including:

compressing the audio signal using a compression method as described in any of the above;

the receiving end receives the audio signal and reconstructs the audio signal by adopting a formula (17) to a formula (21) to obtain the decoded audio signal,

A＝argmin||θ·F||₀s.t.A＝θ·F， (17)

wherein s.t. is a representation-restricted, A is the observation matrix, θ is a measurement matrix, F is the audio signal after the thinning process,

wherein λ is_tThe index found for the t-th iteration, N is the number of elements of the measurement matrix theta, r_t-1The residual error when t is t-1,is the jth column, [ lambda ] of the sensing matrix phi_tIs a set of indices of t iterations ^_t-1Set of indices for t-1 iterations, phi_tSet of reconstructed atoms of the sensing matrix phi for the t-th iteration_t-1The reconstructed set of atoms for the sensing matrix phi for the t-1 th iteration,

is lambda of the sensing matrix_tThe columns of the image data are,

is a sparse approximation of the audio signal F,for the value of the audio signal of the t-th iteration, r_tThe values updated for the decoded residual.

Optionally, the transmission method includes presetting an audio acquisition system to acquire the audio signal, where the audio acquisition system includes:

the audio acquisition node is arranged on the site and used for acquiring the audio signal;

a first processor for performing the compression method of any one of claims 1 to 5;

communication means for transmitting the compressed audio signal;

a terminal for receiving the audio signal and decoding the audio signal using formula (17) to formula (21).

In yet another aspect, the present invention also provides a transmission system for an audio signal of a live pig, the transmission system comprising a processor for executing the transmission method as described above.

In yet another aspect, the present invention also provides a storage medium storing instructions for reading by a machine to cause the machine to perform a method as claimed in any one of the above.

According to the technical scheme, the method and the system for compressing the audio signal of the live pig sequentially perform conversion, weighting, normalization operation and windowing and framing processing on the audio signal to obtain the effective signal part in the audio signal, and then compress the effective part by adopting a spectral subtraction method, so that the technical problems of information collision and congestion of the audio signal of the live pig during transmission in the prior art are solved. The transmission method and the transmission system for the audio signals of the live pigs, provided by the invention, overcome the technical problems of information collision and congestion of the audio signals of the live pigs during transmission in the prior art by adopting the compression method and the compression system, and improve the transmission efficiency and the accuracy of the audio signals.

Additional features and advantages of embodiments of the invention will be set forth in the detailed description which follows.

Drawings

The accompanying drawings, which are included to provide a further understanding of the embodiments of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the embodiments of the invention without limiting the embodiments of the invention. In the drawings:

fig. 1 is a flowchart of a transmission method for an audio signal of a live pig according to an embodiment of the present invention;

FIG. 2 is a graph of the amplitude-frequency characteristics of a high pass filter according to one embodiment of the invention;

FIG. 3 is a phase frequency characteristic diagram of a high pass filter according to an embodiment of the invention;

FIG. 4 is a time domain waveform diagram of an audio signal before and after being processed by a high pass filter according to one embodiment of the present invention;

FIG. 5 is a graph of the spectral change of an audio signal before and after being subjected to a high pass filter according to one embodiment of the present invention;

FIG. 6 is a time domain waveform diagram of a Hamming window function and an amplitude characteristic diagram of the Hamming window function according to an embodiment of the present invention;

FIG. 7 is a graph of a control waveform for a short-term energy-averaged zero-crossing rate according to an example of the present invention; and

fig. 8 is a flow chart of a spectral subtraction method according to an embodiment of the present invention.

Detailed Description

The following detailed description of embodiments of the invention refers to the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating embodiments of the invention, are given by way of illustration and explanation only, not limitation.

In the embodiments of the present invention, unless otherwise specified, the use of directional terms such as "upper, lower, top, and bottom" is generally used with respect to the orientation shown in the drawings or the positional relationship of the components with respect to each other in the vertical, or gravitational direction.

In addition, if there is a description of "first", "second", etc. in the embodiments of the present invention, the description of "first", "second", etc. is for descriptive purposes only and is not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In addition, technical solutions between the various embodiments can be combined with each other, but must be realized by a person skilled in the art, and when the technical solutions are contradictory or cannot be realized, the combination of the technical solutions should be considered to be absent and not be within the protection scope of the present invention.

Fig. 1 is a flowchart illustrating a compression method for an audio signal of a live pig according to an embodiment of the present invention. In fig. 1, the compression method may include:

in step S10, an audio signal is acquired. In this embodiment, the frequency of acquiring the audio signal may be that the audio signal is acquired every predetermined time period, and the compression method is applied to the audio signal acquired each time for immediate processing.

In step S11, the audio signal is converted into a digital signal mode.

In step S12, the audio signal is subjected to emphasis processing. The inventor of the present application found in the actual analysis of the audio signal that the high frequency signal portion of the audio signal of the live pig includes a large amount of information, and the attenuation of the high frequency signal portion is also large. In this embodiment, therefore, the audio signal may be subjected to emphasis processing. Specifically, the high frequency signal portion of the audio signal may be subjected to an emphasis process, so as to eliminate the noise interference of the low frequency signal portion of the audio signal, and simultaneously enhance the spectral components of the audio signal. More specifically, the transfer function of the emphasis process may be formula (1),

H(z)＝1-αz^-1， (1)

where h (z) is a transfer function of the high-pass filter, z is a variation z-domain in the process of processing the audio signal, and α is a pre-emphasis coefficient. The range of values for the pre-emphasis coefficient α may be a plurality of values known to those skilled in the art. In one example of the present invention, the pre-emphasis coefficient α may range from 0.9 to 1.0. Preferably, the pre-emphasis coefficient α may be 0.98 in consideration of the processing effect of the emphasis process. Accordingly, the specific operation of the emphasis process may then include performing the emphasis process according to equation (2),

s(n)＝x(n)-αx(n-1)， (2)

where s (n) is the audio signal after emphasis processing, x (n) is the speech sample value at the time n of the audio signal, and x (n-1) is the speech sample value at the time n-1 of the audio signal. In this embodiment, the amplitude-frequency characteristic of the high-pass filter may be as shown in fig. 2, and the phase-frequency characteristic may be as shown in fig. 3. The time domain waveform of the audio signal before and after the high pass filter processing is shown in fig. 4, and the signal spectrum change before and after the high pass filter processing is shown in fig. 5.

In step S13, a normalization operation is performed on the emphasized audio signal.

In step S14, the audio signal after the normalization operation is subjected to windowing framing processing. In this embodiment, the speech signal is approximately constant for a period of 10-30ms, considering that the audio signal after the normalization operation is a short-time stationary signal. Then, the state of dividing the speech signal into frames can be processed using a windowing frame division process. During this windowing framing process, the ratio of the frame shift to the frame length may range from 0 to 0.5. In particular, the windowed framing process may be processing the audio signal according to, for example, equations (3) and (4),

q＝s(n)*w(n)， (3)

wherein q is the audio signal after windowing and framing, s (N) is the audio signal before windowing and framing, w (N) is a Hamming window function, and N is the window length of the Hamming window function. For the determination of the window length, it is considered that an excessively narrow window length may cause truncation effect in the windowing framing processing, and an excessively long window length may cause signal transition of the windowing framing processing to be excessively smooth. Therefore, in a preferred example of the present invention, the window length may preferably be 60. The time domain waveform diagram of the Hamming window function and the amplitude characteristic diagram of the Hamming window function can be as shown in FIG. 6.

In step S15, endpoint detection is performed on the windowed and framed audio signal to determine a valid signal portion of the audio signal. In this embodiment, considering that the audio signal is directly captured from the scene by the audio capturing device, more noise and unwanted signal portions tend to be included in the audio signal. These noise and unwanted signal components not only increase the computation and processing time of the system, but also reduce the recognition rate of the system during compression and subsequent processing. Thus, in this embodiment, the windowed framing processed audio signal may be end-point detected to determine a valid signal portion of the audio signal. Therefore, the calculation amount of the system is reduced, and the recognition rate of the system is improved. Specifically, the step S15 may include determining the effective signal part of the audio signal according to formula (5) to formula (6),

wherein E is_nIs the short-time energy of the audio signal, M is the number of frames of the audio signal, q_nIs the nth frame of the audio signal. Where the short-time energy is the sum of the squares representing the truncated sample values. A larger temporal energy represents more voiced sounds of the truncated sample value (audio signal), while a relatively smaller temporal energy represents more unvoiced sounds of the truncated sample value. Therefore, the transition time of the unvoiced and voiced sounds of the audio signal can be determined according to the change of the short-time energy, so that the boundary of the effective signal part and the ineffective signal part of the audio signal is measured. Specifically, the short-term energy is rapidly increased when the valid signal portion is generated, and it is confirmed that the point is a boundary between the invalid signal portion and the valid signal portion. Further, the change in the short-term energy may also be used to determine the noise of the inactive signal portion, e.g. when the short-term energy suddenly increases and becomes smaller immediately, the portion of the audio signal may be determined as noise. In addition, considering the limitation of the number of computer bits, overflow is easy to occur in the process of calculating short-time energy, so the method is compatible with the computerIn a preferred embodiment of the invention, the short-term average amplitude can be used instead of the short-term energy calculation, and the variation characteristics of the two are consistent. Specifically, the short-time average amplitude can be calculated using equation (5-1),

where M (n) is the short-time average amplitude, M is the number of frames of the audio signal, q_nIs the nth frame of the audio signal.

Wherein Z is_nIs the average zero-crossing rate, q, of the audio signal_nIs the nth frame of the audio signal and M is the number of frames of the audio signal. In this embodiment, since the audio signal is obtained by sampling, when the values of adjacent discrete speech signals are opposite, a zero point must exist therebetween, and the process of the audio signal passing through the zero point can be referred to as a "zero crossing" phenomenon. Accordingly, the number of times the audio signal passes through the zero point in the unit time may be referred to as a zero-crossing rate. The average zero-crossing rate is an average value of zero-crossing rates of the audio signal in a plurality of unit times. For the specific process of judging the effective signal part and the ineffective signal part of the audio signal by adopting the average zero-crossing rate, the interval with higher average zero-crossing rate can be unvoiced, and the interval with lower average zero-crossing rate can be voiced. The boundary of the active and inactive signal portions may also be determined based on the average zero crossing rate. Fig. 7 is a graph of a control waveform of the short-term energy-averaged zero-crossing rate according to an example of the present invention.

In particular, the process of determining the valid signal portion in the audio signal in combination with the short-time energy and the average zero-crossing rate may be, for example: a low threshold is first set based on one of the short-time energy and the average zero-crossing rate, and a high threshold is set based on the other. When the audio signal exceeds the lower threshold, the segment of the audio signal may be a starting point, i.e. a starting point of the active signal portion. When the audio signal exceeds the upper threshold, the segment of the audio signal may be a speech portion, i.e. an actual valid signal portion.

In this way, the audio signal can be divided into four sections, i.e., a silence section, a transition section, a speech section, and an end section. In the silence period, both the short-time energy and the average zero crossing rate are smaller than the low threshold; in the transition section, both the short-time energy and the average zero crossing rate are smaller than a low threshold; in a voice section, the short-time energy and/or the average zero crossing rate exceed a high threshold; in the ending section, both the short-time energy and the average zero-crossing rate are less than the low threshold. Finally, the speech segment may be taken as the active signal portion.

In step S16, a valid signal portion is extracted as a pre-processed audio signal.

In step S17, the pre-processed audio signal is compressed using spectral subtraction. In particular, the spectral subtraction method may comprise the steps as illustrated in fig. 8. In this fig. 8, the spectral subtraction method may include:

in step S20, the audio signal is subjected to the thinning-out operation using the formulas (7) to (13),

y(n)＝q(n)+d(n)， (7)

wherein y (n) is the nth frame of the audio signal with noise Y (n), q (n) is the pure part of the audio signal, d (n) is the nth frame of the noise part of the audio signal D (n);

wherein Y (omega) is a polar coordinate form of the audio signal Y (n) with noise, | Y (omega) | is a corresponding amplitude spectrum,

is the phase spectrum of the audio signal y (n) with noise,

is the phase of the audio signal y (n),

wherein D (omega) is the polar coordinate form of the noise part D (n) in the audio signal, | D (omega) | is the corresponding amplitude spectrum,

the phase spectrum of the noisy portion d (n),the phase of the noise portion d (n),

wherein f (ω) is a polar coordinate form of the audio signal, Y (ω) is a polar coordinate form of the noisy audio signal Y (n),

is an estimate of D (co),

is the phase spectrum of the audio signal y (n) with noise,

is the phase of the audio signal y (n),

where F (k) is the DCT transform of the audio signal f, f (i) is the ith frame of the audio signal f, n is the number of frames of the audio signal f,

F＝α·f， (13)

wherein, F is the audio signal after the sparsification processing, alpha is a standard orthogonal base, and F is the audio signal before the sparsification processing;

in step S21, an observation matrix of the audio signal is constructed according to formula (14) to formula (16) to obtain a compressed audio signal,

M≥cKlog(N/K)＜＜N， (15)

wherein epsilon belongs to (0, 1), theta is a preset measurement matrix of M multiplied by N, F is an audio signal after sparsification processing, K is a value of sparsity, alpha is a standard orthogonal base, F is the audio signal before sparsification processing, A is an observation matrix,is a sensing matrix.

In another aspect, the invention also provides a compression system for an audio signal, which may comprise a processor operable to perform a compression method as described in any one of the above.

In another aspect, the present invention also provides a transmission method for an audio signal of a live pig, which may include:

compressing the audio signal using a compression method as described in any of the above;

the receiving end receives the audio signal and reconstructs the audio signal by adopting the formula (17) to the formula (21) to obtain a decoded audio signal,

A＝argmin||θ·F||₀s.t.A＝θ·F， (17)

wherein s.t. is the expression, A is the observation matrix, theta is the measurement matrix, F is the audio signal after the thinning processing,

wherein λ is_tThe index found for the t-th iteration, N is the number of elements of the measurement matrix theta, r_t-1The residual error when t is t-1,

is a sensing matrix phi (and a sensing matrix)Same) j row, ^_tIs a set of indices of t iterations ^_t-1Set of indices for t-1 iterations, phi_tSet of reconstructed atoms of the sensing matrix phi for the t-th iteration_t-1The reconstructed set of atoms for the sensing matrix phi for the t-1 th iteration,

is lambda of the sensing matrix_tThe columns of the image data are,

is a sparse approximation of the audio signal F,

for the value of the audio signal of the t-th iteration, r_tThe values updated for the decoded residual.

In one embodiment of the invention, the transmission method may include presetting an audio acquisition system to acquire an audio signal. The audio acquisition system comprises an audio acquisition node 01, a first processor 02, a communication device 03 and a terminal 04.

The audio collection node 01 may be located in the field for collecting audio signals. The first processor 02 may be adapted to perform a compression method as described in any of the above, thereby compressing the audio signal. The communication device 03 may be used for transmitting compressed audio signals. The terminal 04 may be configured to receive the audio signal and decode the audio signal using the formulas (17) to (21), thereby completing the transmission of the audio signal.

In a further aspect, the invention also provides a transmission system for an audio signal of a live pig, which may comprise a processor, which may be configured to perform the transmission method as described above.

In yet another aspect, the present invention also provides a storage medium which may store instructions which are readable by a machine to cause the machine to perform any one of the methods described above.

According to the technical scheme, the method and the system for compressing the audio signal of the live pig sequentially perform conversion, weighting, normalization operation and windowing and framing processing on the audio signal to obtain the effective signal part in the audio signal, and then compress the effective part by adopting a spectral subtraction method, so that the technical problems of information collision and congestion of the audio signal of the live pig during transmission in the prior art are solved. The transmission method and the transmission system for the audio signals of the live pigs, provided by the invention, overcome the technical problems of information collision and congestion of the audio signals of the live pigs during transmission in the prior art by adopting the compression method and the compression system, and improve the transmission efficiency and the accuracy of the audio signals.

Although the embodiments of the present invention have been described in detail with reference to the accompanying drawings, the embodiments of the present invention are not limited to the details of the above embodiments, and various simple modifications can be made to the technical solution of the embodiments of the present invention within the technical idea of the embodiments of the present invention, and the simple modifications all belong to the protection scope of the embodiments of the present invention.

It should be noted that the various features described in the above embodiments may be combined in any suitable manner without departing from the scope of the invention. In order to avoid unnecessary repetition, the embodiments of the present invention will not be described separately for the various possible combinations.

Those skilled in the art can understand that all or part of the steps in the method for implementing the above embodiments may be implemented by a program to instruct related hardware, where the program is stored in a storage medium and includes several instructions to enable a (may be a single chip, a chip, etc.) or a processor (processor) to execute all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and other various media capable of storing program codes.

In addition, various different embodiments of the present invention may be arbitrarily combined with each other, and the embodiments of the present invention should be considered as disclosed in the disclosure of the embodiments of the present invention as long as the embodiments do not depart from the spirit of the embodiments of the present invention.