Audio transmission link anomaly detection method, program product and system

Abstract

The invention provides an audio transmission link anomaly detection method, a program product and a system, is applied to link anomaly detection between decoding side equipment and encoding side equipment, and belongs to the technical field of audio transmission link detection. Embedding a preset feature code sequence into a sample point data unit of the digital audio signal data stream; and the coding side device analyzes the received data stream, extracts the feature code sequence and detects the feature code sequence to obtain a link anomaly detection result. The method does not need to depend on a network protocol and signaling interaction, directly detects the audio data transmission abnormality, effectively detects the abnormality of the intermediate node equipment and the physical link, and accurately and reliably monitors the state of the audio transmission link in real time. According to the technical scheme, the implementation method is simple and efficient, hardware level integration is easy, the method is particularly suitable for audio real-time transmission scenes of high-safety and cross-physical isolation networks, and the information safety of an isolation gateway system can be effectively guaranteed.

Description

Background Art

[0002] In the high-security field, the secure exchange of audio information across physically isolated networks is of great importance. Security devices such as isolation gateways or air gaps are widely used to build physically isolated network environments to ensure the security of internal classified networks. However, the existing technologies have deficiencies in the abnormal detection of audio transmission links across physically isolated networks, making it difficult to effectively guarantee the reliability and quality of audio data transmission.

[0003] Traditional audio transmission systems rely on systems, drivers, and applications to ensure transmission quality and lack an effective link abnormal detection mechanism, making it difficult to quickly discover and locate transmission link failures in the audio digital signal data stream. Especially in the scenario of an isolation gateway where audio data is transmitted across devices through a hardware link between the decoding-side device and the encoding-side device, the existing technologies have the following prominent problems in the abnormal detection of audio transmission links: First, there is a lack of the ability to detect abnormal audio data at internal nodes of the isolation gateway. In the isolation gateway system shown as Figure 1 below, audio data needs to be transmitted through hardware links via internal nodes such as FPGAs and optical modules between the decoding-side and encoding-side devices. The existing technologies lack effective monitoring of the audio data status of these internal nodes. Once the FPGA processing at the decoding-side or encoding-side device is abnormal or the output data is abnormal, it may cause abnormalities in the transmission of audio data within the isolation gateway and is difficult to be detected and located in a timely manner, affecting the system reliability. Second, it is unable to effectively detect abnormal audio data across physically isolated links. The isolation gateway system relies on physically isolated links, such as optical fiber links, to achieve secure isolation. However, when audio data is transmitted across physically isolated links, it is vulnerable to factors of the link itself or external environmental interference, resulting in abnormalities such as bit errors and packet losses during data transmission, and ultimately causing abnormal audio data received by the encoding-side device. The existing technologies usually can only subjectively judge through the final audio playback quality at the receiving end and cannot directly and effectively detect whether there are abnormalities in the audio data during the transmission across physically isolated links.

[0004] Therefore, for the audio transmission link across physically isolated networks, especially in the specific scenario of a hardware link connection between the decoding-side device and the encoding-side device, there is an urgent need for an effective technical solution that can embed effective monitoring features in the audio data transmission link to facilitate real-time detection and identification of audio data link abnormalities, thereby accurately diagnosing audio transmission link failures and determining the audio data transmission quality in real time to ensure the information security of the isolation gateway system. The existing technologies have obvious deficiencies in the above specific scenarios and requirements and cannot provide effective means for detecting abnormal audio transmission links. Summary of the Invention

[0005] Aiming at the problem that in the prior art, there is a lack of effective detection means in the scenario of an isolation gateway across a physically isolated network for abnormal detection of an audio transmission link, the purpose of the present invention is to provide an audio transmission link abnormal detection method, program product and system. By embedding a preset feature code sequence into the digital audio signal data stream, it is possible to effectively detect in real time whether an abnormality occurs in the hardware link between the decoding-side device and the encoding-side device without relying on a network communication protocol, thereby providing a reliable guarantee for the secure exchange of audio information in a high-security isolated network environment and solving the technical problem that the prior art cannot effectively detect abnormalities in intermediate nodes and physical links.

[0006] An embodiment of the present invention provides an audio transmission link abnormal detection method, which is applied to link abnormal detection between a decoding-side device and an encoding-side device, and includes the following steps:

[0007] Embed a preset feature code sequence into the sample point data unit of the digital audio signal data stream to generate a digital audio signal data stream containing the feature code sequence;

[0008] Transmit the digital audio signal data stream containing the feature code sequence from the decoding-side device to the encoding-side device through the transmission link;

[0009] The encoding-side device parses the received digital audio signal data stream containing the feature code sequence and extracts the received feature code sequence;

[0010] Detect the received feature code sequence against the preset feature code sequence to obtain a link abnormal detection result.

[0011] In some optional embodiments, the embedding method includes the following steps:

[0012] For each sample point data unit in the digital audio signal data stream, insert the preset feature code sequence into the sample point data unit to expand the data bit width of the sample point data unit from the first bit width to the second bit width, generating a digital audio signal data stream containing the feature code sequence.

[0013] In some optional embodiments, the embedding is based on the frame rate of the digital audio signal data stream to obtain the number of periods, and the preset feature code sequence is embedded into the digital audio signal data stream according to the number of periods.

[0014] In some optional embodiments, the second bit width is twice the first bit width.

[0015] In some optional embodiments, the step in which the encoding-side device parses the received digital audio signal data stream containing the feature code sequence and extracts the received feature code sequence includes:

[0016] Using pointer offset operations, adjust the pointer type for accessing the digital audio signal data stream, and adjust the pointer for accessing the sample point data unit from the second bit width pointer to the first bit width pointer, so as to realize differentiating and reading the sample point data unit and the feature code sequence in the digital audio signal data stream in the access mode of the first bit width pointer.

[0017] In some optional embodiments, after the step of the decoding-side device embedding a preset feature code sequence into the decoded digital audio signal data stream to generate a digital audio signal data stream containing the feature code sequence, the method further includes:

[0018] In the decoding-side device, expand the digital audio signal data stream containing the feature code sequence with the first channel number to the second channel number to generate a digital audio signal data stream with the second channel number, where the second channel number is greater than the first channel number.

[0019] In some optional embodiments, the audio transmission link anomaly detection method further includes the following steps:

[0020] In the decoding-side device, embed the preset feature code sequence into the digital audio signal data stream in a frame-first storage order;

[0021] In the encoding-side device, convert the received digital audio signal data stream in a frame-first storage order into a channel-first storage order.

[0022] In some optional embodiments, when detecting the received feature code sequence and the preset feature code sequence, the obtained detection results include:

[0023] Extract the received feature code sequence and compare it with the preset feature code sequence;

[0024] If the comparison results are inconsistent, record them in the form of counting as the anomaly detection results.

[0025] The audio transmission link anomaly detection method proposed by the present invention embeds a preset feature code sequence into the digital audio signal data stream on the decoding side device, and extracts and detects this feature code sequence on the encoding side device, achieving effective monitoring of the audio transmission link status and making up for the deficiencies of the prior art in link anomaly detection. By embedding a feature code sequence into the digital audio signal data stream, the present invention can directly detect whether anomalies occur during the transmission of audio data without relying on complex network protocols and signaling interactions. It can not only detect end-to-end transmission errors, but also effectively detect anomalies in intermediate node devices and physical links, thereby monitoring the audio transmission link status in real time, accurately, and reliably. In addition, the implementation method of the present invention is simple, easy to deploy and maintain. Only the feature code embedding needs to be performed on the decoding side device, and the feature code extraction and detection need to be performed on the encoding side device, without significantly modifying the existing audio transmission system, effectively saving system resource overhead. Compared with the prior art that indirectly infers the link status by subjectively judging the audio playback quality, the method of the present invention can more directly, accurately, and reliably detect audio transmission link anomalies, improving the reliability and quality of audio data transmission.

[0026] An embodiment of the present invention further provides an audio transmission link anomaly detection program product. The program product includes computer instructions, and when the computer instructions are executed by a processor, the steps of the above-mentioned audio transmission link anomaly detection method are implemented, and thus the beneficial effects of the above-mentioned audio transmission link anomaly detection method can be obtained.

[0027] By adopting the audio transmission link anomaly detection program product provided by the present invention, the steps of the audio transmission link anomaly detection method implemented when the program stored therein is executed, and thus the beneficial effects of the above-mentioned audio transmission link anomaly detection method can be obtained.

[0028] An embodiment of the present invention further provides an audio transmission link anomaly detection system, which is applied to the above-mentioned audio transmission link anomaly detection method, and includes a decoding side device and an encoding side device. The decoding side device includes a feature code sequence embedding module, and the encoding side device includes a feature code sequence parsing module. Among them, the feature code sequence embedding module embeds the feature code sequence into the digital signal data stream, and the feature code parsing module extracts the received feature code sequence and compares it with the preset feature code sequence to obtain the transmission link status result.

[0029] An audio transmission link anomaly detection system provided by an embodiment of the present invention is applied to the above-mentioned audio transmission link anomaly detection method, integrates a feature code sequence embedding module and a feature code sequence parsing module, and realizes systematic and integrated detection of audio transmission link anomalies. This system can construct a complete closed-loop for audio transmission link anomaly detection between the decoding-side device and the encoding-side device without relying on additional external devices or software. Compared with traditional detection schemes that rely on external devices or software, this system is more integrated, efficient, and automated, can provide more stable, faster, and more reliable link anomaly detection results, and can reflect the status of the audio transmission link in real time, facilitating users to locate and handle link failures in a timely manner, effectively ensuring the reliability and quality of audio data transmission, and is particularly suitable for audio information security exchange scenarios with high security and cross-physical isolation networks. In addition, this system adopts a modular design, is easy to integrate and expand, can be flexibly applied to various audio transmission systems, and has good versatility and application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Other features, objects, and advantages of the present invention will become more apparent by reading the detailed description of the non-limiting embodiments with reference to the following drawings.

[0031] Figure 1 It is a schematic diagram of the audio transmission link structure of the isolation gateway system according to an embodiment of the present invention;

[0032] Figure 2 It is a flowchart of the audio transmission link anomaly detection method according to an embodiment of the present invention;

[0033] Figure 3 It is a schematic diagram of the structure of the audio transmission link anomaly detection system according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0034] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in various forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this invention will be thorough and complete, and will fully convey the concept of the example embodiments to those skilled in the art. Like reference numerals in the figures denote like or similar structures, and thus their repetitive description will be omitted.

[0035] The audio transmission link anomaly detection method of the present invention aims to realize real-time monitoring and anomaly detection of the audio transmission link state by embedding a preset feature code sequence into the digital audio signal data stream. During the audio data transmission process, any form of damage or change, such as data loss, signal interference, hardware failure, etc., may cause the signal to change, affecting the integrity and quality of audio data transmission. Most traditional audio transmission link monitoring methods rely on analyzing the playback quality of the finally received audio. These methods usually can only indirectly infer the state of the link, and lack effective intermediate node and physical link anomaly detection means, making it difficult to accurately locate the fault point and unable to reflect the state of the transmission link in real-time or near real-time.

[0036] In the decoding-side device of the present invention, a preset feature code sequence is embedded into the sample point data unit of the decoded digital audio signal data stream, and the feature code sequence is extracted and detected on the encoding-side device side, transforming the detection of the audio transmission link state from traditional audio quality assessment to direct detection and comparison of the preset feature code sequence. The preset feature code sequence is known information. By comparing whether the received feature code sequence on the encoding-side device side is consistent with the preset feature code sequence, it is possible to directly and real-time detect whether any changes occur during the audio data transmission process, thereby realizing precise monitoring and anomaly detection of the audio transmission link state. When any anomaly occurs in the audio transmission link, such as hardware failure of the intermediate node, damage to the transmission medium, or signal interference, the feature code sequence extracted by the encoding-side device will be inconsistent with the preset feature code sequence embedded by the decoding-side device, and it can be determined that the audio transmission link has an anomaly, so as to accurately locate the link problem and handle it in a timely manner. Different from traditional technologies, the present invention does not need to rely on subjective judgment and indirect speculation of the quality of the final audio data, but obtains real-time feedback of the link state by directly comparing the feature code sequences, which can effectively overcome the limitations of traditional technologies and realize effective detection of anomalies in the internal nodes of the isolation gateway and audio data across the physical isolation link.

[0037] As Figure 2 shown, the present invention provides an audio transmission link anomaly detection method, which is applied to the link anomaly detection between the decoding-side device and the encoding-side device, and includes the following steps:

[0038] S100. Embed a preset feature code sequence into the sample point data unit of the digital audio signal data stream to generate a digital audio signal data stream containing the feature code sequence;

[0039] In an embodiment of the present invention, at the sending end of audio data transmission, i.e., the decoding-side device, a preset signature sequence is added to the sample point data unit of the digital audio signal data stream to form a new digital audio signal data stream containing the signature sequence. Among them: the preset signature sequence refers to a set of known digital sequences preset for detecting abnormalities in the audio transmission link. By adding the signature sequence as a "mark" or "watermark" in the audio data transmission link, the receiving end can determine whether the transmission link is abnormal by detecting whether the "mark" or "watermark" has changed. The specific form, length, and content of the signature sequence can be flexibly set according to actual application requirements. For example, a fixed-value sequence, a random code sequence, a pseudo-random code sequence, or a check code sequence with specific verification functions can be used. In this embodiment, a fixed-value sequence can be used, such as a fixed-value sequence represented by a hexadecimal number like "0x5aa5", as the preset signature sequence. Using a fixed-value sequence as the signature sequence has the advantages of simple implementation, easy detection and comparison, and can meet the basic requirements for detecting abnormalities in the audio transmission link. In other embodiments, in order to improve the reliability or security of detection, a more complex signature sequence can also be used, such as a pseudo-random code sequence or a check code sequence with specific verification functions. For the specific selection of the signature sequence, those skilled in the art can flexibly design and adjust according to actual application requirements, and the present invention does not make specific limitations thereon.

[0040] The digital audio signal data stream refers to the data stream of the audio signal represented in digital form, which is the basic form for the transmission and processing of audio data in the digital signal processing system. In an embodiment of the present invention, the digital audio signal data stream refers to the original digital audio signal output after the decoding-side device decodes the audio data in the first coding format received. The digital audio signal data stream can be a PCM (Pulse Code Modulation) data stream. The PCM data stream is a commonly used uncompressed digital audio coding format that can truly and completely restore the original audio signal and is easy to perform digital signal processing. Therefore, in an embodiment of the present invention, the PCM data stream is used as the carrier of the digital audio signal data stream. In other embodiments, according to specific application scenarios and system requirements, the digital audio signal data stream can also adopt other suitable digital audio signal formats, such as LPCM, ADPCM, etc., and the present invention does not make specific limitations thereon.

[0041] A sample point data unit refers to the smallest data unit that constitutes the data stream of a digital audio signal. The data stream of a digital audio signal is composed of a series of discrete sample point data, and each sample point data represents the amplitude value of the audio signal at a specific time point. In the embodiments of the present invention, the sample point data unit can be each independent sampling point data in the data stream of the digital audio signal. For example, for a PCM data stream with a 16-bit width, each sample point data unit is usually 16 bits, that is, 2 bytes; for a PCM data stream with a 32-bit width, each sample point data unit is usually 32 bits, that is, 4 bytes. The technical solution of the present invention embeds and detects the feature code sequence based on the sample point data unit as the basic unit, and can realize more refined and accurate abnormal monitoring of the audio transmission link.

[0042] The embedding operation refers to the specific method or operation of adding a preset feature code sequence to the data stream of the digital audio signal. The selection of the embedding method needs to comprehensively consider factors such as the concealment, robustness, impact on the original audio data, and implementation complexity of the embedding. In the embodiments of the present invention, the embedding method is to insert the preset feature code sequence into the data bit positions of the sample point data unit, that is, at the data bit level of the sample point data unit, insert the data bits of the feature code sequence into the data bits of the sample point data unit. Of course, in other embodiments, according to the specific application scenario and system requirements, the embedding method of the feature code sequence can also adopt other feasible methods, such as inserting the preset feature code sequence into the head or tail of the data stream of the digital audio signal, or replacing some data bits in the data stream of the digital audio signal, etc. The present invention does not make a unique limitation on the specific embedding method. For the specific implementation of the embedding in a predetermined manner, those skilled in the art can flexibly select and adjust according to the actual application scenario.

[0043] S200. Transmit the digital audio signal data stream containing the feature code sequence from the decoding-side device to the encoding-side device through the transmission link;

[0044] In an embodiment of the present invention, a digital audio signal data stream containing a feature code sequence is transmitted from a decoding-side device to an encoding-side device through an audio transmission link for subsequent extraction of the feature code sequence and link anomaly detection operations on the encoding-side device. The transmission link is usually an optical fiber link. The optical fiber link has the advantages of long transmission distance, large bandwidth, strong anti-interference ability, high security, etc., and is especially suitable for audio data transmission scenarios with high security and across physically isolated networks. Specifically, the optical fiber link can be composed of hardware components such as an optical module of the decoding-side device, a transmission optical fiber, and an optical module of the encoding-side device. The decoding-side device can convert the digital audio signal data stream containing the feature code sequence into an optical signal and transmit the optical signal to the optical module of the encoding-side device through the optical fiber. The optical module of the encoding-side device receives the optical signal and converts it into a digital audio signal data stream for subsequent parsing and processing of the received digital audio signal data stream by the encoding-side device. Using an optical fiber link as the audio transmission link can effectively ensure the safe and reliable transmission of audio data in a cross-physically isolated network environment and meet the requirements of high-security application scenarios. In other embodiments, according to specific application scenarios and system requirements, the transmission link can also use other types of wired or wireless links, such as an Ethernet link, a wireless link, or via an FPGA board, etc. The present invention does not uniquely limit the specific type of transmission link.

[0045] S300. The encoding-side device parses the received digital audio signal data stream containing the feature code sequence and extracts the received feature code sequence.

[0046] In an embodiment of the present invention, at the receiving end of audio data transmission, that is, the encoding-side device, the received digital audio signal data stream containing the feature code sequence is parsed and processed, and the pre-embedded feature code sequence is extracted from the received data stream for subsequent link anomaly detection and status evaluation. In this embodiment, after the audio acquisition module of the encoding-side device, such as the CAP module, receives the digital audio signal data stream containing the feature code sequence, a feature code sequence extraction operation is performed through the feature code sequence parsing module.

[0047] S400. The received feature code sequence is detected against a preset feature code sequence to obtain a link anomaly detection result.

[0048] In an embodiment of the present invention, at the receiving end of audio data transmission, i.e., the encoding-side device, the extracted received feature code sequence is compared and detected with a pre-set feature code sequence to determine whether the two are the same or meet a pre-set similarity threshold. According to the comparison and detection results, a detection result on whether the audio transmission link is abnormal is obtained for subsequent abnormal processing and alarm prompting. Specifically, the detection method can include various implementation manners. In this embodiment, the received redundant check code sequence is extracted and compared bit by bit or in segments with the pre-set redundant check code sequence. If the comparison results are inconsistent, for example, the received redundant check code sequence is completely inconsistent with the pre-set redundant check code sequence, or the number of inconsistent bits exceeds the pre-set threshold, it is determined that the audio transmission link is abnormal, and the number of inconsistent bits or the number of error codes is recorded in the form of counting as the link abnormality detection result, and the link abnormality detection result is fed back to the upper-layer application or management system through a pre-set interface for subsequent abnormal processing, alarm prompting, log recording, link maintenance, etc. The method of comparing the redundant check code sequences for link abnormality detection has the advantages of simple implementation, high detection efficiency, and low misjudgment rate. It can quickly and effectively detect various abnormal situations occurring in the audio transmission link and quantify the degree of abnormality, providing a reference basis for subsequent abnormal processing. In other embodiments, according to the different types of feature code sequences and different requirements for detection accuracy and detection efficiency, the detection method can also adopt other appropriate algorithms or strategies, such as the Hamming distance detection algorithm, similarity matching algorithm, bit error rate statistical method, etc. The present invention does not uniquely limit the specific detection method, as long as it can accurately and reliably determine whether the audio transmission link is abnormal based on the difference between the received feature code sequence and the pre-set feature code sequence.

[0049] In some embodiments, the optical fiber link includes the field programmable gate array (FPGA) of the decoding board, the transmission optical fiber, and the field programmable gate array (FPGA) of the encoding board. The digital signal data stream is transmitted from the decoding board to the encoding board through the field programmable gate array (FPGA) of the decoding board, the transmission optical fiber, and the field programmable gate array (FPGA) of the encoding board. The embodiment of the present invention uses the FPGA as the optical fiber interface to realize the conversion between the electrical signal and the optical signal, so as to use the optical fiber link for high-speed and long-distance data transmission.

[0050] Embodiments of the present invention do not need to rely on complex network protocols such as the TCP / IP protocol or additional signaling interaction mechanisms. By only embedding and detecting a preset feature code sequence in the audio data stream, effective monitoring and anomaly detection of the audio transmission link status can be achieved, reducing the system complexity and resource overhead, and improving the detection efficiency and real-time performance. It can effectively detect audio data anomalies that may occur in various links such as internal nodes of the isolation gateway (such as the decoding-side device FPGA, the encoding-side device FPGA, optical modules, etc.) and across physical isolation links (such as fiber optic links), making up for the deficiencies of the prior art in link anomaly detection and improving the coverage and accuracy of audio transmission link anomaly detection. The feature code embedding and extraction process of the embodiments of the present invention is simple and efficient, and is easy to implement by software or hardware means. For example, the stripping of the feature code sequence can be achieved through C language pointer offset operations, or corresponding hardware modules can be integrated in the decoding-side device and the encoding-side device, so as to accelerate the embedding, extraction, and detection processes of the feature code sequence at the hardware level, improve the detection efficiency and real-time performance of the system, and reduce the system power consumption and cost. By directly comparing the received feature code sequence with the preset feature code sequence, the embodiments of the present invention can detect in real time, accurately, and reliably whether anomalies occur during the transmission of audio data, and feedback the link anomaly detection results to the upper layer in the form of counting, facilitating users to locate and handle link failures in a timely manner, effectively ensuring the reliability and quality of audio data transmission, and meeting the requirements in high-security application scenarios. The embodiments of the present invention have no special restrictions on the audio coding format and transmission link type, can be flexibly adapted to different audio transmission systems and application scenarios, have good versatility and application prospects, and are particularly suitable for audio real-time transmission scenarios in high-security and cross-physical isolation networks, such as government agencies, military defense, financial security, radio and television, conference systems, telemedicine, video surveillance, and other fields.

[0051] In some embodiments, the embedding method includes the following steps: for each sample point data unit in the digital audio signal data stream, insert a preset feature code sequence into the sample point data unit to expand the data bit width of the sample point data unit from the first bit width to the second bit width, and generate a digital audio signal data stream containing the feature code sequence. In this embodiment, by expanding the data bit width of the sample point data unit, the preset feature code sequence is inserted or embedded into the sample point data unit, thereby generating a digital audio signal data stream containing the feature code sequence. The embedding operation of the feature code sequence is performed for each sample point data unit in the digital audio signal data stream to ensure that the feature code sequence can be evenly and completely embedded into the entire digital audio signal data stream, improving the coverage rate and reliability of link anomaly detection. By using the insertion method to embed the feature code sequence, the feature code sequence can be added to the digital audio signal data stream while maximizing the retention of the original audio data, minimizing the impact of the embedding of the feature code sequence on the quality of the original audio data itself, ensuring the effectiveness and fidelity of the audio signal, and avoiding perceptible distortion or noise caused by the embedding of the feature code sequence to the audio signal, thereby affecting the audio playback quality and user experience. Data bit width expansion is a preferred but not the only way to implement the insertion of the feature code sequence. The first bit width refers to the data bit width of the sample point data unit of the original digital audio signal data stream. For example, for a 16-bit PCM data stream, the first bit width is 16 bits. The second bit width refers to the data bit width of the sample point data unit after the feature code sequence is embedded. The second bit width is greater than the first bit width. For example, after inserting a 16-bit preset feature code sequence into a 16-bit sample point data unit, the second bit width is 32 bits, that is, the second bit width is twice the first bit width. By using the technical means of data bit width expansion to embed the feature code sequence, its implementation is simple and efficient. Data bit width expansion is a direct and effective way to embed the feature code sequence, which is relatively simple and efficient both in software or hardware implementation, and is easy to integrate into the existing audio processing system without introducing excessive computational complexity and resource overhead. For example, in software implementation, through simple bit operation instructions such as shift operation and bitwise OR operation, the expansion of the data bit width and the insertion of the feature code sequence can be quickly realized. In hardware implementation, through simple hardware logic circuits or programmable devices such as FPGAs, the data bit width expansion and the feature code sequence embedding operation can be efficiently completed to meet the application requirements of audio real-time transmission. The way of data bit width expansion is to expand and insert data bits inside the sample point data unit, without changing the basic format and structure of the digital audio signal data stream, having no special requirements for parameters such as the encapsulation format, sampling rate, and number of channels of the audio data stream, and having good compatibility, and can be applicable to various different audio coding formats and audio transmission systems.The feature code sequence and the valid audio data are fused in the same sample point data unit and transmitted and processed as a whole. They can jointly experience various losses and interferences in the transmission link, have good synchronization and robustness, are convenient for accurate extraction and detection at the receiving end, reduce the bit error rate and the missed detection rate, and improve the reliability of link anomaly detection.

[0052] In the embodiment of the present invention, the decoding-side device receives the audio data in the first coding format and decodes it to obtain a digital audio signal data stream, such as a PCM audio data stream with a sampling rate of 48 kHz, 16 channels, and 16 bits, as shown in the valid data on the decoding side in Table 1.

[0053] Table 1

[0054]

[0055] The transmission link adopts the isolation gateway transmission link configuration as shown in Figure 1 . In it, the sound card and FPGA parts are configured with an audio data transmission format of 32 channels and 32 bits. For each sample point data unit in the digital audio signal data stream, a preset feature code sequence is inserted into the sample point data unit, so that the data bit width of the sample point data unit is expanded from the first bit width to the second bit width, generating a digital audio signal data stream containing the feature code sequence. In this embodiment, the preset feature code sequence is configured as a fixed numerical sequence "0x5aa5" for example, the first bit width is 16 bits, and the second bit width is 32 bits. The specific embedding in the predetermined manner is: after each 16-bit valid audio data, such as "0x0000", the 16-bit feature code sequence "0x5aa5" is inserted, so as to expand the 16-channel, 16-bit audio data into 16-channel, 32-bit audio data. The modified audio data format is shown in the converted data on the decoding side in Table 2.

[0056] Table 2

[0057]

[0058] Due to the hardware and to adapt to the number of FPGA channels, the actual number of data channels processed is twice that of the valid data, and there is a situation of data replication. Therefore, it is necessary to copy and expand the original 16-channel data into 32-channel data to match the FPGA hardware configuration. That is, the data in channels 0-7 and 8-15 in the 32 channels is the same, and the data in channels 16-23 and 24-31 is the same.

[0059] In the embodiments of the present invention, the number of channels is extended through data replication, which solves the problem of inconsistency between the hardware and driver configurations and the number of effective data channels, and ensures the compatibility of the system. The data insertion and replication operations are simple and easy to implement on hardware or software, reducing the complexity of system implementation. By inserting the feature data after each piece of effective data instead of replacing the original data, the integrity of the original audio information is maximally retained. Although this embodiment is described by taking the example of expanding 48kHz 16-channel 16-bit audio data to 32-channel 32-bit data, the present invention is not limited thereto. Those skilled in the art can adjust the formats of the original data and the target data according to actual needs, such as expanding to other combinations of the number of channels and bits. The way of channel replication can also be adjusted according to the actual situation, for example, different replication strategies can be adopted or other data expansion methods can be used.

[0060] By expanding the digital audio signal data stream including the feature code sequence with the first channel number to the second channel number in the decoding-side device, a digital audio signal data stream with the second channel number can be generated, which can effectively solve the problem of mismatch between the number of effective channels of the audio data and the number of channels configured by the hardware device driver, make full use of the processing capacity and transmission bandwidth of the hardware device, improve the utilization rate of hardware resources and the transmission efficiency of audio data, and ensure the optimization of the overall performance of the system.

[0061] In some embodiments, the number of cycles is obtained by embedding the frame rate of the digital audio signal data stream in a predetermined manner, and the preset feature code sequence is embedded into the digital audio signal data stream according to the number of cycles. Specifically, the preset number of cycles can be determined according to the frame rate of the audio data, such as the frame rate of 100 frames per second corresponding to a 48kHz sampling rate and a 10ms frame length. For example, the preset cycle is set to each frame of audio data, that is, for each frame of audio data processed, an embedding operation of the feature code sequence is performed, thereby realizing the periodic embedding of the feature code sequence and ensuring that the feature code sequence appears periodically in the digital audio signal data stream, which is convenient for the recognition, extraction and detection of the feature code sequence at the receiving end. For example, if the audio sampling rate is 48kHz, there are 48000 sampling points per second. Associating the cycle tree with the frame rate of the audio data can make the embedding of the feature code more reasonable and efficient. For example, the preset cycle can be determined according to multiples of the audio sampling rate, so as to ensure that the feature code is embedded at least once in each audio frame or video frame, or the feature code is embedded once in multiple frames. For example, for audio data, if the sampling rate is 48kHz and the preset cycle is 1ms, then each cycle contains 48 sampling points. The feature code sequence can be embedded once every 48 sampling points. In some other embodiments, different feature code sequences can be embedded in different cycles to achieve different detection purposes.

[0062] The embedding by a predetermined method is performed periodically, and the period is determined according to the frame rate of the audio data. This technical feature can achieve the synchronization of the feature code sequence embedding operation and the audio data frame structure, enabling the embedding and extraction operations of the feature code sequence to be better combined with the audio data frame processing process, and ensuring the synchronization and real-time performance of the audio data frame processing.

[0063] In some embodiments, the encoding-side device parses the received digital audio signal data stream containing the feature code sequence and extracts the received feature code sequence. In this embodiment, the audio acquisition module of the encoding-side device, such as the CAP module, receives 32-channel 32-bit audio data containing the feature code sequence. Its data arrangement is configured as 32-channel 32-bit data according to the underlying driver, and the storage order in memory is as shown in the data after decoding-side conversion in Table II. The encoding-side device needs to separate the high 16-bit feature data and the low 16-bit valid data from the received 32-channel 32-bit audio data and extract the high 16-bit feature code sequence for subsequent link anomaly detection. Specifically, the pointer function of C language can be used, and technical means such as pointer offset operation and adjustment of pointer type can be adopted. Without changing the memory data storage order, the extraction of the feature code sequence can be realized efficiently and conveniently. The specific extraction steps may include: using pointer offset operation to adjust the pointer type for accessing the digital audio signal data stream, and changing the pointer for accessing the sample point data unit from the second bit-width pointer to the first bit-width pointer, so as to realize distinguishing and reading the sample point data unit and the feature code sequence in the digital audio signal data stream in the first bit-width pointer access mode. The original 4-byte pointer pointing to 32-bit data per channel is changed to a 2-byte pointer pointing to 16-bit data, thereby adjusting the pointer type for accessing the digital audio signal data stream, and changing the pointer for accessing the sample point data unit from the second bit-width pointer, i.e., the 4-byte pointer, to the first bit-width pointer, i.e., the 2-byte pointer, to realize distinguishing and reading the sample point data unit and the feature code sequence in the digital audio signal data stream in the first bit-width pointer access mode. That is, each pointer offset operation only accesses and reads the low 16-bit bits in the 32-bit data, and the high-bit feature code sequence is automatically ignored or skipped, thereby realizing the separation of the high 16-bit data feature data and the low 16-bit data valid data, and converting the 32-channel 32-bit audio data into 64-channel 16-bit data for subsequent processing. The converted audio data format is as shown in Table III Feature Data Stripping. The audio data shown in Table III Feature Data Stripping is 64-channel 16-bit data. Among them, the even channels, such as channels A0, A2,..., A62, are the stripped high 16-bit feature data, and the odd channels, such as channels A1, A3,..., A63, are the separated low 16-bit valid data. The memory data storage order remains unchanged, but for the feature code sequence parsing operation, the data operation has changed from the 32-channel 32-bit data shown in the data after decoding-side conversion in Table II to the 64-channel 16-bit data shown in Table III Feature Data Stripping.

[0064] Table III

[0065]

[0066] Since only valid data is required for the final data processing and application, that is, the odd-channel data of A1, A3, ..., A63 shown in the feature data stripping of Table 3, while the link anomaly detection requires the use of feature data, that is, the even-channel data of A0, A2, ..., A62 shown in the feature data stripping of Table 3. To simplify the data fetching logic and anomaly detection function logic at the subsequent stage, the feature code sequence transposes and changes the memory data storage order, changing the memory data storage order from the frame-first storage order shown in the feature data stripping of Table 3 to the channel-first storage order shown in Table 4 after simplified processing, thus facilitating the subsequent memory data processing. The transposition of the memory data storage order can be implemented using pointer operations in C language code. For example, two 16-bit pointers `Src` and `Dst` can be defined, pointing to the original data buffer `buf` and the target data buffer `empty buf` respectively, and then through loop traversal and pointer offset operations, the data in the original data buffer `buf` is transposed and stored in the target data buffer `empty buf` according to the channel-first storage order shown in Table 4. Through the above memory data storage order transposition operation, the encoding-side device can more conveniently process the audio data in units of frames or channels at the subsequent stage, effectively simplifying the subsequent data processing logic and improving the data processing efficiency and code readability.

[0067] Table 4

[0068]

[0069] In some embodiments, the signature sequence includes at least one of a redundancy check code sequence, a signature sequence with timestamp information, and a link state identifier signature sequence. By including different information in the signature sequence in the embodiments of the present invention, the functions of the signature sequence are extended, enabling it to implement various link state detection and evaluation functions. The redundancy check code sequence is a coding method used to detect whether errors occur during data transmission. Common redundancy check codes include parity check codes, cyclic redundancy check codes (CRC), etc. By adding a redundancy check code to the data, the receiving end can detect whether errors have occurred during data transmission and perform error correction or retransmission as needed. In the present invention, the redundancy check code sequence can be used to detect whether errors have occurred in the signature sequence itself during transmission, thereby improving the reliability of link state detection. For example, a CRC check code can be used to verify the signature sequence to ensure the integrity and accuracy of the signature sequence. The signature sequence with timestamp information refers to including timestamp information in the signature sequence. The timestamp is used to record the generation or transmission time of the signature sequence. By comparing the timestamps at the sending end and the receiving end, the delay experienced by the data during transmission can be calculated, thereby evaluating the delay situation of the link. This is very useful for applications with high requirements for delay, such as real-time audio and video communication, etc. The timestamp can be an absolute time (such as UTC time) or a relative time (such as an offset relative to a certain reference time). The link state identifier signature sequence is a signature sequence used to identify the link state. Different link states can be represented by different identifiers. The sending end can select the corresponding identifier as part of the signature sequence for embedding according to the current link state. The receiving end can understand the current link state by detecting the link state identifier in the received signature sequence.

[0070] In some embodiments, the received signature sequence is detected against a preset signature sequence, and the detection results obtained include:

[0071] Extract the received signature sequence and compare it with the preset signature sequence;

[0072] If the comparison results are inconsistent, record them in the form of a count as abnormal detection results.

[0073] In an embodiment of the present invention, the received feature code sequence is compared with a preset feature code sequence to determine whether they are the same or whether they meet a preset similarity threshold. The preset feature code sequence is a known sequence preset in advance when the feature code is embedded in the decoding-side device, and the received feature code sequence is the feature code sequence extracted by the encoding-side device from the received digital audio signal data stream. By comparing the received feature code sequence with the preset feature code sequence bit by bit or in segments, it is possible to effectively detect whether data errors or anomalies have occurred in the audio transmission link. The comparison of the feature code sequences can directly detect whether the data has changed during the transmission process, and has a high detection sensitivity to various types of link anomalies, such as bit errors, packet losses, data disorders, timing disorders, or signal interferences. As long as any slight change occurs in the audio data during the transmission process, it may cause the received feature code sequence to be inconsistent with the preset feature code sequence, and thus be detected, realizing precise monitoring of the state of the audio transmission link. By recording the link anomaly detection results in a digital counting manner, the degree of link anomalies can be quantified. For example, the more bits that are inconsistent, or the larger the number of error codes, the more serious the degree of link anomalies, thus providing a quantitative reference basis for subsequent anomaly handling and maintenance, facilitating the system to adopt corresponding processing strategies according to different degrees of anomalies. For example, for minor link anomalies, warning prompts or log records can be made, while for serious link anomalies, more advanced anomaly handling measures such as automatic switching, redundant backup, or manual intervention can be triggered, improving the intelligence and automation level of the system.

[0074] As Figure 3 shown, an embodiment of the present invention further provides an audio transmission link anomaly detection system, which is applied to the feature code-based audio transmission link anomaly detection method described in the above embodiment and is used to implement the anomaly detection of the audio data transmission link across the physically isolated link between the decoding-side device and the encoding-side device. The system mainly includes a decoding-side device M100 and an encoding-side device M200. The decoding-side device M100 mainly includes: a feature code sequence embedding module M110, an audio decoding module M120, and a data sending module M130; the encoding-side device M200 mainly includes: a feature code sequence parsing module M210, a data receiving module M220, and a detection module M230. The specific composition, connection relationship, and function description of each functional module are as follows:

[0075] Audio decoding module M120: It is set in the decoding-side device M100 and is used to receive audio data in the first encoding format, decode the received audio data according to the first encoding format, and convert it into a digital audio signal data stream, such as a PCM data stream, for subsequent embedding of the feature code sequence and cross-physical isolation link transmission. In the embodiments of the present invention, the audio decoding module M120 can be implemented by a software decoder, a hardware decoder, or a combination of software and hardware. The specific decoding algorithm and implementation method can be flexibly selected according to the type of the first encoding format. For example, if the first encoding format is the AAC format, the audio decoding module M120 can use an AAC decoder for decoding; if the first encoding format is the MP3 format, the audio decoding module M120 can use an MP3 decoder for decoding. The present invention does not uniquely limit the specific implementation method and decoding algorithm of the audio decoding module M120.

[0076] Feature code sequence embedding module M110: It is set in the decoding-side device M100 and is connected to the audio decoding module M120. It is used to receive the digital audio signal data stream output by the audio decoding module M120, and embed the preset feature code sequence into the sample point data unit of the digital audio signal data stream according to a predetermined method to generate a digital audio signal data stream containing the feature code sequence for subsequent cross-physical isolation link transmission through the data sending module M130, and perform feature code sequence extraction and link anomaly detection on the encoding-side device M200 side. In the embodiments of the present invention, the feature code sequence embedding module M110 can be implemented by a software module, a hardware module, or a combination of software and hardware. The specific embedding method and implementation method can refer to the relevant description of step S100 in the method embodiment. For example, the 16-bit preset feature code sequence can be inserted into the high 16-bit of the 16-bit sample point data unit by expanding the data bit width, so that the data bit width of the sample point data unit is expanded from the first bit width (16-bit) to the second bit width (32-bit), thereby generating a 32-bit digital audio signal data stream containing the feature code sequence. The feature code sequence embedding module M110 can obtain the number of cycles based on the frame rate of the audio data, and periodically embed the preset feature code sequence into the digital audio signal data stream according to the number of cycles to achieve periodic embedding of the feature code sequence. In addition, the feature code sequence embedding module M110 can also expand the digital audio signal data stream containing the feature code sequence with the first channel number to the second channel number to adapt to the driver configuration of hardware devices such as audio sound cards and FPGAs. For the specific implementation method and internal structure of the feature code sequence embedding module M110, those skilled in the art can flexibly design and adjust according to actual application requirements, and the present invention does not make specific limitations thereon.

[0077] Data sending module M130: It is set in the decoding-side device M100 and is connected to the feature code sequence embedding module M110. It is used to receive the digital audio signal data stream containing the feature code sequence output by the feature code sequence embedding module M110, and transmit the digital audio signal data stream containing the feature code sequence from the decoding-side device M100 to the encoding-side device M200 through the audio transmission link, so as to perform subsequent feature code sequence parsing and link anomaly detection on the encoding-side device M200 side. In the embodiment of the present invention, the audio transmission link is preferably an optical fiber link. The data sending module M130 can be a hardware device such as an optical module or an optical fiber transceiver, which is used to convert the digital audio signal data stream containing the feature code sequence into an optical signal and send the optical signal to the encoding-side device M200 through the optical fiber link. In other embodiments, according to specific application scenarios and system requirements, the data sending module M130 can also adopt other types of wired or wireless data sending modules to adapt to different types of audio transmission links. For example, when the audio transmission link is an Ethernet link, the data sending module M130 can be an Ethernet network card or an Ethernet PHY chip, etc.; when the audio transmission link is a wireless link, the data sending module M130 can be a WiFi module or a Bluetooth module, etc. The present invention does not uniquely limit the specific implementation manner and hardware type of the data sending module M130.

[0078] Data receiving module M220: It is set in the encoding-side device M200 and is used to receive the digital audio signal data stream transmitted by the data sending module M130 of the decoding-side device M100 through the audio transmission link, that is, the digital audio signal data stream containing the feature code sequence, and output the received data stream to the feature code sequence parsing module M210 for subsequent processing. In the embodiment of the present invention, the audio transmission link is preferably an optical fiber link. Corresponding to the data sending module M130 of the decoding-side device M100, the data receiving module M220 can be a hardware device such as an optical module or an optical fiber transceiver, which is used to receive the optical signal transmitted by the decoding-side device M100 through the optical fiber link and convert the optical signal into a digital audio signal data stream, so that the subsequent encoding-side device M200 can parse and process the received digital audio signal data stream. In other embodiments, corresponding to the data sending module M130, the data receiving module M220 can also adopt other types of wired or wireless data receiving modules to adapt to different types of audio transmission links. For example, when the audio transmission link is an Ethernet link, the data receiving module M220 can be an Ethernet network card or an Ethernet PHY chip, etc.; when the audio transmission link is a wireless link, the data receiving module M220 can be a WiFi module or a Bluetooth module, etc. The present invention does not uniquely limit the specific implementation manner and hardware type of the data receiving module M220 either.

[0079] Feature code sequence parsing module M210: It is set in the encoding-side device M200 and is connected to the data receiving module M220. It is used to receive the digital audio signal data stream containing the feature code sequence output by the data receiving module M220, and parse the received data stream to extract the preset feature code sequence contained therein, so as to perform link anomaly detection and status evaluation through the detection module M230 subsequently. In the embodiment of the present invention, the feature code sequence parsing module M210 can be implemented in the form of a software module, a hardware module, or a combination of software and hardware. The specific parsing and extraction methods can refer to the relevant description of step S300 in the method embodiment. For example, by using technical means such as the offset operation of C language pointers and adjusting the pointer type, without changing the memory data storage order, it is possible to efficiently and conveniently distinguish and read the sample point data unit and the feature code sequence from the received digital audio signal data stream containing the feature code sequence, thereby realizing the accurate extraction of the feature code sequence. For the specific implementation manner and internal structure of the feature code sequence parsing module M210, those skilled in the art can flexibly design and adjust according to actual application requirements, and the present invention does not make specific limitations thereon.

[0080] Detection module M230: It is set in the encoding-side device M200 and is connected to the feature code sequence parsing module M210. It is used to receive the feature code sequence extracted by the feature code sequence parsing module M210, and compare and detect the received feature code sequence with the preset feature code sequence to obtain the audio transmission link anomaly detection result, so as to perform subsequent anomaly processing and alarm prompts. In the embodiment of the present invention, the detection module M230 can be implemented in the form of a software module, a hardware module, or a combination of software and hardware. The specific detection methods and implementation manners can refer to the relevant description of step S400 in the method embodiment. For example, the "feature code sequence comparison" detection method can be adopted to compare the received redundant check code sequence with the preset redundant check code sequence. If the comparison results are inconsistent, the link anomaly detection result is recorded in the form of counting and fed back to the upper-layer application or management system through a preset interface. For the specific implementation manner and internal structure of the detection module M230, those skilled in the art can flexibly design and adjust according to actual application requirements, and the present invention does not make specific limitations thereon.

[0081] In some embodiments, the decoding-side device M100 and the encoding-side device M200 can be independent hardware devices, such as a decoding board and an encoding board, which are connected through a physically isolated link such as an optical fiber link to form an isolation gateway system across a physically isolated network, and are applied to the audio information security exchange scenario of high security and across a physically isolated network. The decoding-side device M100 can be deployed on the non-secret network or the external network side to receive and decode the audio data of the external network. The encoding-side device M200 can be deployed on the secret network or the internal network side to receive and encode the audio data from the decoding-side device and perform subsequent security processing and applications. The audio data is transmitted between the decoding-side device M100 and the encoding-side device M200 through a physically isolated audio transmission link, avoiding direct interconnection and interoperability at the network protocol level and ensuring the security of the internal network.

[0082] In some embodiments, the audio decoding module M120, the feature code sequence embedding module M110, and the data sending module M130 can be integrated and implemented in hardware chips or software modules such as FPGA (Field Programmable Gate Array) chips, DSP (Digital Signal Processor) chips, ASIC (Application Specific Integrated Circuit) chips, or SoC (System on Chip) of the decoding-side device M100; the data receiving module M220, the feature code sequence parsing module M210, and the detection module M230 can be integrated and implemented in hardware chips or software modules such as FPGA chips, DSP chips, ASIC chips, or SoC chips of the encoding-side device M200. The modular design of the system makes the system structure clearer. Each functional module can be independently designed, developed, and tested, is easy to implement and maintain, and can be flexibly trimmed, replaced, and extended according to actual application requirements, improving the flexibility, scalability, and reconfigurability of the system.

[0083] An embodiment of the present invention also provides an audio transmission link anomaly detection program product. The program product includes computer instructions, and when the computer instructions are executed by a processor, the steps of the above-mentioned audio transmission link anomaly detection method are implemented.

[0084] Those skilled in the art of the present technology can understand that various aspects of the present invention can be implemented as a system, a method, or a program product. Therefore, various aspects of the present invention can be specifically implemented in the following forms, namely: a complete hardware implementation, a complete software implementation (including firmware, microcode, etc.), or an implementation combining hardware and software aspects, which can be collectively referred to as "circuit", "module", or "system" here.

[0085] The above content is a further detailed description of the present invention in combination with specific preferred embodiments. It cannot be determined that the specific implementation of the present invention is only limited to these descriptions. For those of ordinary skill in the technical field to which the present invention pertains, without departing from the concept of the present invention, several simple deductions or substitutions can still be made, and all should be regarded as belonging to the protection scope of the present invention.

Claims

1. A method for detecting anomalies in an audio transmission link, applied to detecting anomalies in a link between a decoding side device and an encoding side device, characterized in that: The steps include: Embedding a preset feature code sequence into a sample point data unit of a digital audio signal data stream to generate a digital audio signal data stream containing the feature code sequence; Transmitting a digital audio signal data stream containing a feature code sequence from a decoding side device to an encoding side device via a transmission link; The encoding side device parses the received digital audio signal data stream containing the feature code sequence and extracts the received feature code sequence; The received feature code sequence is detected with the preset feature code sequence to obtain a link anomaly detection result.

2. The method for detecting anomalies in an audio transmission link according to claim 1, characterized in that: The embedding method comprises the following steps: For each of the sample point data units in the digital audio signal data stream, a preset feature code sequence is inserted into the sample point data unit so that the data bit width of the sample point data unit is expanded from a first bit width to a second bit width, thereby generating a digital audio signal data stream containing the feature code sequence.

3. The method for detecting anomalies in an audio transmission link according to claim 2, characterized in that: The embedding obtains a period number based on the frame rate of the digital audio signal data stream, and embeds a preset feature code sequence into the digital audio signal data stream according to the period number.

4. The method for detecting anomalies in an audio transmission link according to claim 2, characterized in that: The second bit width is twice the first bit width.

5. The method for detecting anomalies in an audio transmission link according to claim 4, characterized in that: The step of the encoding side device parsing the received digital audio signal data stream containing the feature code sequence and extracting the received feature code sequence comprises: By using a pointer offset operation, the pointer type used to access the digital audio signal data stream is adjusted, and the pointer for accessing the sample point data unit is adjusted from a second-bit-width pointer to a first-bit-width pointer, so as to achieve the distinction between reading the sample point data unit and the feature code sequence in the digital audio signal data stream by using the first-bit-width pointer access method.

6. The method for detecting anomalies in an audio transmission link according to claim 1, characterized in that: After the decoding side device embeds a preset feature code sequence into the digital audio signal data stream output by decoding to generate a digital audio signal data stream containing the feature code sequence, the step further includes: In the decoding side device, a digital audio signal data stream containing a feature code sequence having a first number of channels is expanded to a second number of channels to generate a digital audio signal data stream having a second number of channels, wherein the second number of channels is greater than the first number of channels.

7. The method for detecting anomalies in an audio transmission link according to claim 1, characterized in that: The following steps are also included: On the decoding side device, the preset feature code sequence is embedded into the digital audio signal data stream in a frame-first storage order; On the encoding side device, the received digital audio signal data stream in a frame-first storage order is converted into a channel-first storage order.

8. The method for detecting anomalies in an audio transmission link according to claim 1, characterized in that: The received feature code sequence is detected with the preset feature code sequence, and the detection result obtained includes: Extracting the received feature code sequence and comparing it with the preset feature code sequence; If the comparison results are inconsistent, they are recorded as abnormal detection results in the form of counts.

9. An audio transmission link anomaly detection program product, characterized in that: The program product includes computer instructions, which, when executed by a processor, implement the steps of the audio transmission link anomaly detection method according to any one of claims 1 to 8.

10. An audio transmission link anomaly detection system, characterized in that: The audio transmission link anomaly detection method applied to any one of claims 1 to 8 comprises a decoding side device and an encoding side device, wherein the decoding side device comprises a feature code sequence embedding module, and the encoding side device comprises a feature code sequence parsing module, wherein the feature code sequence embedding module embeds the feature code sequence into a digital signal data stream, and the feature code parsing module extracts the received feature code sequence and compares it with a preset feature code sequence to obtain a transmission link status result.

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