Video and audio file security management method and system

Abstract

The invention discloses a video and audio file security management method and system, and belongs to the technical field of file security, video and audio files are stored in a buffer area after being collected by a camera, the capacity of the buffer area is adjusted according to the network bandwidth and the change of the number of bytes of the files, and source identification information is coded and embedded and then stored in a security storage area; key marking operation of a user on the video and audio files in the secure storage area is monitored, key interval fragments are extracted, key marking information is obtained through screening and recognition, and then a multi-dimensional metadata structure positioning index is constructed; for video and audio files in a secure storage area, an initial encryption key is generated based on a metadata structure positioning index of the files, and then the encryption level is determined according to the data size and format of the files and hierarchical encryption is carried out. The technical problems of buffer area capacity self-adaption in video and audio file collection and storage, key mark information processing after user operation, index construction and the like are solved, and transmission, tracing, management and safety protection of video and audio files are guaranteed.

Description

Technical Field

[0001] The present invention relates to the field of file security technology, and more specifically to a method and system for secure management of video and audio files. Background Art

[0002] With the rapid development of science and technology, cameras have been widely used in news reporting, documentary filming, self-media creation and other fields. These application scenarios have generated a large number of audio and video files, which has also brought severe file management challenges, highlighting the importance of security management methods and systems. In the encoding of camera audio and video files, a reasonable encoding method can better preserve the quality and details of audio and video under limited storage resources. For example, the use of advanced video encoding standards can effectively compress file size, facilitate file storage and transmission, and also lay the foundation for subsequent security management operations. Some encoding algorithms can reserve specific fields for embedding security identification or encrypted information carriers. The key marking and retrieval functions are of great significance to the management of camera-shot materials. In news gathering work, reporters may shoot a large amount of material in one day. By marking key information, people, places, etc., such as marking speech clips of important people and scenes of emergencies, valuable content can be quickly retrieved from many files in the later stage, which greatly improves work efficiency and reduces the time cost of material sorting. File encryption is the key line of defense to ensure the security of camera audio and video files. Encryption technology can ensure that these files are not obtained, viewed or tampered with by unauthorized third parties during the process of being stored in the camera's memory card, transferred to computers or other devices, and shared with specific personnel, thereby safeguarding the rights and interests of all parties and information security, and ensuring that the camera's video and audio files are under safe and reliable management throughout their life cycle.

[0003] The Chinese patent with the authorization announcement number CN107977551B discloses a method, device and electronic device for protecting files, which relates to file security technology and can ensure the integrity of the content of MP4 files. The method for protecting files includes: obtaining an index box contained in a target file; writing digital copyright management information in a user data box in the index box; updating a sample-to-block mapping table box and a block offset box in the index box of the target file according to the written digital copyright management information and the position of the index box in the target file; and digitally signing the updated target file.

[0004] Although the existing technology guarantees the integrity of the MP4 file content, it still fails to solve the technical problems of adaptively adjusting the buffer capacity and embedding the source identifier during the acquisition and storage of audio and video files, extracting key mark information and building multi-dimensional indexes when users browse and play, so as to ensure stable transmission, easy traceability and convenient management of audio and video files: Therefore, in order to overcome these limitations, the present invention proposes a method and system for secure management of audio and video files. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention aims to provide a method and system for the security management of audio-visual files, which solves the following problems: first, during the transmission of audio-visual files, the buffer capacity cannot be adaptively adjusted according to the real-time transmission rate and data volume of the file, which is prone to data overflow or shortage, thereby affecting the continuous reception of audio-visual files and the overall transmission stability; second, the source identification information of the audio-visual files is not deeply embedded, making it difficult to clearly mark and reliably trace key attributes such as the source of the file; third, when users browse, play and make key marking operations on the stored audio-visual files, there is a lack of effective mechanisms to accurately extract audio-visual clips in key intervals, filter key frames, identify targets, and extract audio data by category, etc., so that a comprehensive and multi-dimensional metadata structure positioning index cannot be constructed, which is not conducive to the subsequent rapid and accurate search and management of related audio-visual files; to achieve the above purposes, the present invention provides the following technical solutions: A video and audio file security management system includes a coding processing module, a key marking module and a security protection module: The encoding processing module is used to store the video and audio files in the buffer when the camera collects them, adjust the buffer capacity by monitoring the changes in network bandwidth and the number of bytes of the video and audio files, and encode and embed the source identification information of the video and audio files in the buffer and store them in the secure storage area; The key mark module is used to monitor the key mark operation of the user when playing or browsing the audio and video files in the secure storage area, extract the audio and video clips in the key interval according to the key mark operation, use the motion change to select the key frames and perform target recognition, extract audio data and classification to obtain the key mark information, and then define the metadata structure template according to the identification information to build a directed graph, and generate a multi-dimensional metadata structure positioning index by processing the newly added identification information records and reviewing the enumeration type records through the comparison function; The security protection module is used to encrypt the audio and video files in the secure storage area, generate an initial encryption key based on the metadata structure positioning index of the audio and video files, determine the encryption level according to the data volume and audio and video file format, and encrypt the audio and video files in a hierarchical manner.

[0006] Specifically, the encoding processing module includes a data buffer unit and an information embedding unit; The data buffer unit is configured with an adaptive buffer strategy, which is used to adjust the buffer capacity in real time according to the transmission rate and data volume of the video and audio files transmitted by the camera. By continuously monitoring the network bandwidth and the changes in the number of bytes of the video and audio files during the transmission of the video and audio files, a buffer state evaluation model is constructed to evaluate the buffer state, so as to dynamically allocate memory space as a buffer; The information embedding unit is configured with a deep fusion strategy, which is used to embed source identification information into the data structure of the audio and video file, and store the processed audio and video file in a secure storage area.

[0007] Specifically, the specific steps of the adaptive buffering strategy include: Set the initial buffer capacity and obtain the camera parameter information; Configure the time window and count the bytes of the audio and video files received within the time window; Configure a sliding window to track the long-term trend and short-term fluctuation of data traffic. Add the number of bytes of audio and video files counted in the time window to the sliding window data sequence, and remove the number of bytes of audio and video files counted in the earliest time window to keep the number of data points in the sliding window fixed. Configure the evaluation interval. At each evaluation interval, calculate the buffer occupancy rate based on the number of occupied buffer bytes and the buffer capacity, and calculate the length of time the buffer can continue to accommodate data. Evaluate the status of the buffer, build a buffer status evaluation model based on the buffer occupancy rate, the duration of data that can be continuously accommodated, and the network bandwidth, and calculate the buffer status evaluation score; Configure the adjustment threshold. If the buffer status evaluation score is less than the adjustment threshold, the buffer capacity increase operation is triggered; otherwise, no processing is performed.

[0008] Specifically, the buffer capacity increase operation includes: Based on the number of bytes of the audio and video files in each sliding window data sequence, calculate the growth rate of the number of bytes in the sliding window; According to the growth rate of the number of bytes in the sliding window and the buffer occupancy rate, the buffer capacity is dynamically increased, that is:

[0009] in, is the adjusted buffer capacity, is the buffer capacity, is the buffer occupancy, is the average growth rate of the number of bytes in the sliding window, and are the minimum and maximum thresholds for the growth rate of the number of bytes in the sliding window, is the buffer occupancy threshold, , and are all weighting coefficients.

[0010] Specifically, the key mark module includes a mark collection unit and an index construction unit; The tag collection unit is configured with a tag capture strategy, which is used to monitor the key tag operations made by the user during the playback or browsing of audio and video files, select key frames through motion change calculation, generate content summaries for key frame target recognition, extract and classify audio data, and identify and extract key tag information; An associated fusion strategy is configured in the index construction unit. The associated fusion strategy is used to index the key mark information and source identification information of the audio and video files, generate a multi-dimensional metadata structure positioning index according to the preset metadata structure template, add metadata structure identification information records through the comparison function, and perform information review on the enumeration type identification information records.

[0011] Specifically, the steps of marking the capture strategy include: When the user starts playing or browsing the video and audio files in the buffer, the focus marking operation is monitored and the focus marking type is identified; By monitoring the user's interactive behavior, the marking time point of the video and audio files where the key marks are located is recorded, and a timestamp is generated for each key mark; According to the key mark type, on the basis of each key mark timestamp, a mark extraction interval is configured, and according to the mark extraction interval, the video and audio clips of the key interval are obtained; Convert the audio and video clips in the key interval into a series of image frames, mark the first image frame as the key frame, configure the vector change threshold, and calculate the motion change of the image frame, that is:

[0012] in, It is Image frames and Image frames The amount of movement change, is the image frame The middle position is The motion vector of is the image frame The middle position is The motion vector of If the amount of motion changes If it is greater than the vector change threshold, Marked as a keyframe, As the starting point, continue to calculate the adjacent motion changes Otherwise, skip , calculate the change in motion , until the traversal of the image frames of the video and audio clip is completed; Perform target recognition on key frames to obtain key mark information of key frames, including text information, target objects, and target scenes, and convert the key mark information recognition results of key frames into text descriptions as content summaries; Extract audio data from audio and video clips in key intervals, identify key tag information of the audio data, classify the audio data, and identify the emotional color of the audio data.

[0013] Specifically, the steps of associating the fusion strategy include: Define a metadata structure template according to the identification information, define the metadata structure as a directed graph, and define an attribute type for each vertex of the metadata structure, the attribute type includes an enumeration type, a string type, and an array type; Obtain identification information records of the video and audio files, and for each obtained identification information record, compare the identification information type with the metadata structure vertex through a comparison function, construct a comparison function between the identification information record and the metadata structure vertex, and query whether there is an identification information type that is the same as the identification information record in the metadata structure vertex; If there is an identification information type that is the same as the identification information record, it means that the identification information type comparison is successful, and the identification information record is filled in the position corresponding to the metadata structure vertex of the same identification information type. If there is no identification information type that is the same as the identification information record, the identification information type comparison fails, and a new temporary metadata structure vertex is created to store the identification information record that failed the comparison.

[0014] Specifically, the steps of associating the fusion strategy also include: When a new identification information record of an audio-visual file is added to the metadata structure, an identification information record with an attribute of an enumeration type is selected for information review to query whether the identification information record of the enumeration type exists in the enumeration type set in the metadata structure; If the identification information type of the existing identification information record is found to be the same as the information type of the identification information record of the newly added audio-visual file in the enumerated type set in the metadata structure, the information review is passed, otherwise the information review is not passed; For information identification records that fail the information review, similar information identification records in the metadata structure are screened and replaced; Calculate the similarity measure between the information identification record that fails the information review and the information identification record of the same information type in the enumeration type set, select the information identification record with the largest similarity measure in the enumeration type set in the metadata structure, and replace the identification information record of the newly added audio and video file.

[0015] Specifically, the security protection module includes a key generation unit and an encryption execution unit; The key generation unit is configured with a feature fusion strategy, which is used to generate an encryption key with dynamic update characteristics for the video and audio files. The feature data is extracted from the metadata structure positioning index of the video and audio files to form an original feature set, and the original feature set is hashed to generate key materials, and the key materials are used as input to generate the initial encryption key; An adaptive encryption strategy is configured in the encryption execution unit. The adaptive encryption strategy is used to perform hierarchical encryption on audio and video files according to an initial encryption key, determine the encryption level by evaluating the data volume and format of the audio and video files, and adaptively encrypt the audio and video files according to the encryption level.

[0016] A method for safely managing video and audio files comprises the following steps: Step S1: When the camera captures an audio and video file, the audio and video file is stored in a buffer, the buffer capacity is adjusted by monitoring the network bandwidth and the number of bytes of the audio and video file, and the source identification information of the audio and video file in the buffer is encoded and embedded and then stored in a secure storage area; Step S2: by monitoring the key marking operation of the user when playing or browsing the audio and video files in the secure storage area, extracting the audio and video segments of the key interval according to the key marking operation, using the motion variation to screen the key frames and perform target recognition, extracting audio data and classification, so as to obtain the key marking information, and then defining the metadata structure template according to the identification information to construct a directed graph, and processing the newly added identification information records and reviewing the enumeration type records through the comparison function to generate a multi-dimensional metadata structure positioning index; Step S3: Encrypt the audio and video files in the secure storage area, generate an initial encryption key based on the metadata structure positioning index of the audio and video files, determine the encryption level according to the data volume and format of the audio and video files, and encrypt the audio and video files in a hierarchical manner.

[0017] Beneficial effects of the present invention: 1. The adaptive buffering strategy in the encoding processing module can monitor the network bandwidth and file byte changes in real time according to the transmission rate and data volume of the audio and video files transmitted by the camera, build an evaluation model and dynamically allocate memory space as a buffer, effectively avoiding data overflow or shortage, ensuring the stability and integrity of the audio and video files during transmission, and ensuring that data can be continuously received and smoothly stored in a safe storage area. This is especially critical for scenarios that require long-term, large-scale audio and video data collection and storage.

[0018] 2. The key marking module uses a marking capture strategy to monitor the key marking operations of users when playing or browsing audio and video files, and then screens key frames, identifies targets, extracts and classifies audio data, etc., to accurately obtain key marking information, which is convenient for users to quickly locate the content of interest later. It also provides a basis for further mining the value of audio and video files based on user feedback. For example, these key marks can be used to generate personalized recommendations and other application scenarios, and the key marking information and source identification information can be indexed to build a multi-dimensional metadata structure positioning index, which is convenient for more efficient retrieval and query of files that meet specific needs in massive audio and video files, thereby improving overall management efficiency.

[0019] 3. The key generation unit of the security protection module has a feature fusion strategy that can extract multiple types of features from the metadata structure location index of the audio and video files to generate an encryption key with dynamic update characteristics. Compared with fixed keys, dynamic update can greatly reduce the risk of key cracking, increase the security of audio and video file encryption, and ensure that data is not illegally obtained and tampered with during storage and subsequent possible transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A schematic diagram of the structure of a video and audio file security management system of the present invention; Figure 2 A flowchart of specific steps of the adaptive buffering strategy of the present invention; Figure 3 The camera structure of the present invention is shown in FIG. Figure 1 ; Figure 4 A flowchart of the specific steps of the tag capture strategy of the present invention; Figure 5 The camera structure of the present invention is shown in FIG. Figure 2 ; Figure 6 A flowchart of the specific steps of the association fusion strategy of the present invention; Figure 7 The present invention is a flowchart of a method for secure management of video and audio files. DETAILED DESCRIPTION

[0021] Example 1 See also Figure 1 ,This embodiment introduces a video and audio file security management system, including an encoding processing module, a key marking module and a security protection module; The encoding processing module is used to store the video and audio files in the buffer when the camera collects the video and audio files, adjust the buffer capacity by monitoring the changes in the network bandwidth and the number of bytes of the video and audio files, and encode and embed the source identification information of the video and audio files in the buffer; Preferably, the encoding processing module includes a data buffer unit and an information embedding unit; The data buffer unit is configured with an adaptive buffer strategy, which is used to adjust the buffer capacity in real time according to the transmission rate and data volume of the video and audio files transmitted by the camera. By continuously monitoring the network bandwidth and the changes in the number of bytes of the video and audio files during the transmission of the video and audio files, a buffer state evaluation model is constructed to evaluate the buffer state, so as to dynamically allocate memory space as a buffer to avoid data overflow or shortage, ensure the stability and integrity of data transmission, and ensure the continuous reception of video and audio files. The information embedding unit is configured with a deep fusion strategy, which is used to embed identification information into the data structure of the audio-visual file, combine the identification information with the audio-visual file, transmit it along with the audio-visual file, and store it in a secure storage area, so as to achieve clear labeling and reliable traceability of key attributes such as the source of the audio-visual file.

[0022] See also Figure 2 Preferably, the specific steps of the adaptive buffering strategy include: See also Figure 3 ,When the WIFI indicator lights up, the video and audio files acquired by the camera are transferred to the buffer, the initial buffer capacity is set, and the camera parameter information is obtained, including resolution, frame rate, encoding format, sampling rate and number of channels; Configuring time windows , the number of bytes of the audio and video files received in the statistical time window is calculated by the audio and video encoding format, resolution and frame rate. By calculating the number of bytes within a fixed time, the changes in data traffic in a short period of time can be obtained in a timely manner, providing basic data points for subsequent sliding window data updates and data traffic analysis. It can monitor the fluctuation of data traffic at a smaller time granularity, so as to more keenly capture the change trend of data traffic; Configuring Sliding Window , used to track long-term trends and short-term fluctuations in data traffic. The sliding window is larger than the time window. The number of bytes of the audio and video files in the internal statistics is added to the sliding window data sequence , and remove the number of bytes of the audio and video files counted in the earliest time window, keeping the number of data points in the sliding window fixed at ,in, is the first The number of bytes of each audio and video file changes with the update of the sliding window; the number of bytes of audio and video files counted in multiple time windows are integrated into a data sequence, which can more comprehensively reflect the overall change characteristics of data traffic over a period of time, including statistical indicators such as the mean and standard deviation of data traffic, thereby providing strong support for accurately evaluating the stability and trend of data traffic, so that the adjustment decision of the buffer capacity is not only based on the current momentary traffic situation, but also comprehensively considers the data traffic change pattern in the past period of time, effectively avoiding misjudgment caused by short-term burst traffic.

[0023] Configure the evaluation interval. Every evaluation interval, the number of bytes in the occupied buffer is used and buffer capacity Calculating buffer occupancy , and calculate the length of time the buffer can continue to hold data :

[0024] in, is the mean number of bytes of the current sliding window data sequence, that is: By calculating the buffer occupancy rate and the duration of data that can be accommodated, the usage of the buffer and the sustainability of the remaining capacity can be timely understood, providing key quantitative indicators for determining whether the buffer capacity needs to be adjusted.

[0025] The buffer status is evaluated. Based on the buffer occupancy rate, the duration of data that can be continuously accommodated, and the network bandwidth, a buffer status evaluation model is constructed to calculate the buffer status evaluation score, namely:

[0026] in, is the buffer state assessment score, is the current network bandwidth, is the set standard network bandwidth, and They are non-negative weighted coefficients, which are used to balance the dimension of buffer occupancy and the length of data that can be continuously accommodated. The overall status of the buffer is quantitatively evaluated by integrating multiple key factors. The calculated buffer status evaluation score provides an intuitive and unified indicator to measure the quality of the buffer.

[0027] Configure the adjustment threshold. If the buffer status evaluation score is less than the adjustment threshold, the buffer capacity increase operation is triggered; otherwise, no processing is performed. Buffer capacity increase operations include: Calculate the growth rate of the number of bytes in the sliding window, that is:

[0028] in, is the first The growth rate of the number of bytes in a time window, is the first Number of bytes of video and audio files, is the first Number of bytes of video and audio files; According to the growth rate of the number of bytes in the sliding window and the buffer occupancy rate, the buffer capacity is dynamically increased, that is:

[0029] in, is the adjusted buffer capacity, is the average growth rate of the number of bytes in the sliding window, , and are the minimum and maximum thresholds for the growth rate of the number of bytes in the sliding window, is the buffer occupancy threshold, , and are non-negative weighted coefficients, which are obtained through testing and verification. When the buffer status evaluation score is less than the adjustment threshold, the buffer capacity increase operation is triggered. By calculating the growth rate of the number of bytes in the sliding window and combining the buffer occupancy rate, a strategy of dynamically increasing the buffer capacity is adopted. The buffer capacity can be accurately adjusted according to the growth trend of data traffic and the current usage of the buffer to ensure that when the data traffic increases, the buffer has enough space to accommodate more data, avoid data overflow, maintain the stability and continuity of data transmission, and avoid excessive capacity increase leading to waste of system resources, improve resource utilization efficiency, and optimize the performance of the entire audio and video file transmission system.

[0030] Preferably, the specific steps of the deep fusion strategy include: Collecting source identification information, including reading the device identification code of the camera, obtaining location information using the built-in positioning module of the camera and obtaining the time information of the video and audio file shooting, and constructing an information set based on the collected source identification information; Perform binary encoding conversion on the information set, convert the information set into a binary code stream sequence, and record the length of the binary code stream sequence; Parse the audio and video files, filter the set of locations where identification information can be embedded, and, for each location, evaluate and obtain the embeddable capacity corresponding to each location; exemplarily, use a calculation method based on information entropy to measure data redundancy, so as to determine the maximum number of bytes that each location can accommodate for identification information, and ensure that the embedding operation will not destroy the basic encoding structure and playback function of the audio and video.

[0031] Embedding the source identification information, using the least significant bit replacement method or the embedding method based on the transform domain to replace the binary bits of the source identification information into the position where the identification information can be embedded; Configure the evaluation threshold and calculate the evaluation index of the audio and video file after the identification information is embedded, including the signal-to-noise ratio, structural similarity index and perceptual audio quality evaluation. If the evaluation index is lower than the evaluation threshold, change the embedding position or strength until the evaluation index of the audio and video file after the identification information is embedded reaches the evaluation threshold.

[0032] The key marking module monitors the key marking operation of users when playing or browsing audio and video files in the secure storage area, extracts the audio and video clips in the key interval according to the key marking operation, selects the key frames and performs target recognition, extracts audio data and classification to obtain the key marking information, and then defines the metadata structure template based on the identification information to build a directed graph, processes the newly added identification information records through the comparison function, and reviews the enumeration type records to generate a multi-dimensional metadata structure positioning index; Preferably, the key mark module includes a mark collection unit and an index construction unit; The tag collection unit is configured with a tag capture strategy, which is used to monitor the key tag operations made by the user during the playback or browsing of audio and video files, select key frames through motion change calculation, generate content summaries for key frame target recognition, extract and classify audio data, and identify and extract key tag information; An associated fusion strategy is configured in the index construction unit. The associated fusion strategy is used to index the key mark information and source identification information of the audio and video files, generate a multi-dimensional metadata structure positioning index according to the preset metadata structure template, add metadata structure identification information records through the comparison function, and perform information review on the enumeration type identification information records.

[0033] See also Figure 4 Preferably, the specific steps of the marking capture strategy include: See also Figure 5 ,When the user starts to play or browse the video and audio files in the buffer, the ,keymarking operation is monitored and the keymarking types are ,identified, including favorite, like, favorite and annotation; By monitoring the user's interactive behavior, the marking time point of the video and audio files where the key marks are located is recorded, and a timestamp is generated for each key mark; According to the key mark type, based on each key mark timestamp, configure the mark extraction interval to determine the number of key frames to extract from the vicinity of the mark point, and obtain the key interval according to the mark extraction interval Video and audio clips of It is timestamp of the highlighted It is The marker extraction interval of the key marker type of the key marker; Convert the audio and video clips in the key interval into a series of image frames, mark the first image frame as the key frame, configure the vector change threshold, and calculate the motion change of the image frame, that is:

[0034] in, It is Image frames and Image frames The amount of movement change, is the image frame The middle position is The motion vector represents the direction and magnitude of the motion at that position. is the image frame The middle position is The motion vector of If the amount of motion changes If it is greater than the vector change threshold, Marked as a keyframe, As the starting point, continue to calculate the adjacent motion changes Otherwise, skip , calculate the change in motion ; Until the image frame traversal of the audio and video clip is completed; Perform target recognition on key frames to obtain key mark information of key frames, including text information, target objects, and target scenes, and convert the key mark information recognition results of key frames into text descriptions as content summaries; Extract audio data from audio and video clips in key intervals, identify key marker information of audio data, including dialogue introduction, sound effects and music type, classify audio data, including dialogue, background music, environmental sounds and special sound effects, and identify the emotional color of audio data, including joy, sadness and anger.

[0035] See also Figure 6 Preferably, the specific steps of associating the fusion strategy include: A metadata structure template is defined according to the identification information, wherein the identification information includes source identification information and key mark information, wherein the source identification information includes the device identification code of the camera, the location information of the video and audio file shooting, and the time information of the video and audio file shooting; the key mark information includes the target object, the target scene, text information, the audio data type, and the audio data color; The metadata structure is defined as a directed graph where the vertex set is , It is Identification information, is the number of identification information types. The elements in the vertex set correspond one-to-one to the identification information of the video and audio files. For example, the device identification code is , the location information of the video and audio file is , the time information of the video and audio file shooting is , the target object is , and so on, thus building a logically clear and hierarchical metadata structure framework, laying the foundation for subsequent information filling and association operations.

[0036] Define an attribute type for each vertex of the metadata structure, the attribute type includes an enumeration type, a string type, and an array type. For example, the device identification code belongs to the string type, and the target object, the target scene, and the audio data type belong to the enumeration type; Get the identification information record of the video and audio files ,in, is the number of identification information obtained, It is Identification information record; For each acquired identification information record, the identification information type is compared with the metadata structure vertex through a comparison function, a comparison function between the identification information record and the metadata structure vertex is constructed, and it is checked whether there is an identification information type identical to the identification information record in the metadata structure vertex; Right now:

[0037] in, It is Identification information record and metadata structure vertex The comparison function of It is The identification information type of each identification information record; If the comparison function The value of , that is, if there is an identification information type that is the same as the identification information record, it means that the identification information type comparison is successful, then the identification information record is filled into the corresponding position of the metadata structure vertex of the same identification information type, that is, Fill in the metadata structure vertex If there is no identification information of the same type as the identification information record in the corresponding position, the comparison function The value of , then the identification information type comparison fails, and a new temporary metadata structure vertex is created to store the identification information record that failed to match; if the identification information comparison fails, that is, the obtained identification information cannot find a type that completely matches it in the existing metadata structure, a new temporary metadata structure vertex is created specifically to store the identification information that failed to match, and at the same time, the relevant reasons for the comparison failure and information characteristics are recorded for further analysis and processing. This flexible processing method can effectively cope with various complex and changeable identification information situations and ensure the integrity and adaptability of the metadata structure.

[0038] When adding an identification information record of an audio or video file to the metadata structure, select an identification information record whose attribute is an enumeration type. Conduct information review, including: For properties of enumeration type Identification information records, among which, The number of identification information records for attributes of enumeration type. Less than If the identification information type of the identification information record found in the enumeration type set in the metadata structure is the same as the information type of the identification information record of the newly added audio and video file, the information review is passed, otherwise the information review is not passed. The formula for information review is:

[0039] in, Is the first property of the enumeration type The review results of the identification information records, Is a collection of enumeration types in the metadata structure, Is the first in the enumeration type collection The identification information type of an identification information record; if If the value is 1, it means there are duplicate records and the information is reviewed. If the value is 0, it means that there are no duplicate records and the information review has not passed. Through this review mechanism, duplicate records or possible data inconsistencies can be discovered in a timely manner, ensuring the uniqueness and accuracy of enumeration type information in the metadata structure, avoiding interference with subsequent data retrieval, association, and analysis operations due to duplicate or erroneous enumeration type records, and helping to maintain the high quality of the metadata structure and the high credibility of the data, so that various applications based on this information can obtain reliable results.

[0040] Records of information identification that failed information review ,in, For the Information identification records that failed, Less than or equal to , filter similar information identification records in the metadata structure for replacement, calculate the similarity measurement value of the information identification records that have not passed the information review and the information identification records of the same information type in the enumeration type set, select the information identification record with the largest similarity measurement value in the enumeration type set in the metadata structure, and replace the identification information record of the newly added audio and video files, that is:

[0041] in, It is The replacement result of the information identification record that failed, Is the enumeration type collection in the metadata structure and The information identification record with the greatest similarity, yes and the similarity measure of the information identifier records in the enumeration type collection, It is to select the information identification record with the largest similarity measurement value. Optimize and correct the potential non-standard and inaccurate enumeration type information in the metadata structure to ensure the rationality and consistency of the data, further improve the overall quality of the metadata structure, so that it can more accurately reflect the actual situation of the audio and video files, enhance the effectiveness and reliability of metadata in supporting application scenarios such as precise retrieval and in-depth analysis, and ensure that the entire audio and video file metadata management system continues to operate efficiently and the data value is fully utilized.

[0042] The security protection module is used to encrypt the audio and video files in the secure storage area, generate an initial encryption key based on the metadata structure positioning index of the audio and video files, and determine the encryption level according to the data volume and format of the audio and video files, and encrypt the audio and video files in a hierarchical manner; Preferably, the security protection module includes a key generation unit and an encryption execution unit; The key generation unit is configured with a feature fusion strategy, which is used to generate an encryption key with dynamic update characteristics for the video and audio files. The feature data is extracted from the metadata structure positioning index of the video and audio files to form an original feature set, and the original feature set is hashed and combined with a dynamic salt value to generate a key material, and the key material is used as input to generate an initial encryption key; An adaptive encryption strategy is configured in the encryption execution unit. The adaptive encryption strategy is used to perform hierarchical encryption on audio and video files according to an initial encryption key, determine the encryption level by evaluating the data volume and format of the audio and video files, and adaptively encrypt the audio and video files according to the encryption level.

[0043] Preferably, the specific steps of the feature fusion strategy include: Extract multiple features from the metadata structure positioning index of the video and audio files, including the specific character segment of the device identification code of the camera, the hash value of the time information of the video and audio files being shot, and the target object category code, to form an original feature set; For the device identification code of the camera, a representative specific character segment is selected, for example, a continuous character segment in the middle is selected, so as to inject unique information closely related to the device into the key; The time when the video and audio files were shot is processed using a hash algorithm to obtain a hash value of the time when the video and audio files were shot; For the target object categories, conversion is performed according to the predefined coding table, and each possible target object is assigned a specific and unique digital code, so that the information of the target object can be integrated into the original feature set in a standardized and easy-to-process form; Perform hash operation on the original feature set to generate an intermediate hash value with a fixed length, and perform XOR and bit expansion and cyclic shift on the dynamic salt value to generate the key material; Set the security strength parameters, use the HKDF key derivation function, take the key material as input, and generate the initial encryption key according to the security strength parameters.

[0044] Preferably, the specific steps of the adaptive encryption strategy include: Evaluate the characteristics of audio and video files, locate indexes through audio and video files and their metadata structures, and obtain key attributes of audio and video files, including the data volume and format of audio and video files; According to the data volume and format of the audio and video files, an encryption level assessment model is constructed. The encryption level assessment model classifies the audio and video files into different encryption levels according to the data volume and format of the audio and video files, including: low level, medium level, and high level. For example, the audio and video files with large data volume and complex audio and video file formats are judged as high level encryption levels. Select an encryption algorithm based on the determined encryption level. A high-level encryption level uses an encryption algorithm with a longer key length, such as AES-256; a low-level encryption level uses an encryption algorithm with a shorter key length, such as AES-128. Calling the initial encryption keys of different lengths generated by the key generation unit, using the selected encryption algorithm and the generated encryption key to encrypt the video and audio files. During the encryption process, different encryption modes such as block encryption and stream encryption are used to adapt to video and audio files of different sizes and formats; After encryption is completed, the encrypted video and audio files are verified to ensure that the encryption process does not damage the file content, and the validity of the encryption key and algorithm is verified through decryption testing; Store encrypted files and key information, store encrypted audio and video files in a secure storage area, and associate the encryption key and related information, including encryption level and algorithm type, with the metadata structure location index of the audio and video files.

[0045] Example 2 See also Figure 7 This embodiment introduces a method for managing video and audio files, including the following steps: Step S1: When the camera captures an audio and video file, the audio and video file is stored in a buffer, the buffer capacity is adjusted by monitoring the network bandwidth and the number of bytes of the audio and video file, and the source identification information of the audio and video file in the buffer is encoded and embedded and then stored in a secure storage area; Step S2: by monitoring the key marking operation of the user when playing or browsing the audio and video files in the secure storage area, extracting the audio and video segments of the key interval according to the key marking operation, using the motion variation to screen the key frames and perform target recognition, extracting audio data and classification, so as to obtain the key marking information, and then defining the metadata structure template according to the identification information to construct a directed graph, and processing the newly added identification information records and reviewing the enumeration type records through the comparison function to generate a multi-dimensional metadata structure positioning index; Step S3: Encrypt the audio and video files in the secure storage area, generate an initial encryption key based on the metadata structure positioning index of the audio and video files, determine the encryption level according to the data volume and format of the audio and video files, and encrypt the audio and video files in a hierarchical manner.

[0046] Preferably, the specific steps of adjusting the buffer capacity include: Set the initial buffer capacity and obtain the camera parameter information, including resolution, frame rate, encoding format, sampling rate and number of channels; Configuring time windows , count the number of bytes of the audio and video files received within the time window; Configuring Sliding Window , used to track long-term trends and short-term fluctuations in data traffic, The number of bytes of the audio and video files in the internal statistics is added to the sliding window data sequence, and the number of bytes of the audio and video files in the earliest time window statistics is removed, keeping the number of data points in the sliding window fixed at ; Configure the evaluation interval. Every evaluation interval, the number of bytes in the occupied buffer is used and buffer capacity Calculate the buffer occupancy rate and the length of time the buffer can continue to hold data ; The buffer status is evaluated. Based on the buffer occupancy rate, the duration of data that can be continuously accommodated, and the network bandwidth, a buffer status evaluation model is constructed to calculate the buffer status evaluation score, namely:

[0047] in, is the buffer state assessment score, is the current network bandwidth, is the set standard network bandwidth, and are the non-negative weighting coefficients respectively; Configure the adjustment threshold. If the buffer status evaluation score is less than the adjustment threshold, the buffer capacity increase operation is triggered; otherwise, no processing is performed. Calculate the growth rate of the number of bytes in the sliding window, that is:

[0048] in, is the first The growth rate of the number of bytes in a time window, is the first Number of bytes of video and audio files, is the first Number of bytes of video and audio files; According to the growth rate of the number of bytes in the sliding window and the buffer occupancy rate, the buffer capacity is dynamically increased, that is:

[0049] in, is the adjusted buffer capacity, is the average growth rate of the number of bytes in the sliding window, and are the minimum and maximum thresholds for the growth rate of the number of bytes in the sliding window, is the buffer occupancy threshold, , and are weighting coefficients respectively.

[0050] Preferably, the specific steps of generating the metadata structure positioning index include: Define the metadata structure template according to the identification information, and define the metadata structure as a directed graph, where the vertex set is , It is Identification information, It is the number of identification information types; the attribute type is defined for each vertex of the metadata structure, and the attribute type includes enumeration type, string type, and array type; Get the identification information record of the video and audio files ,in, is the number of identification information obtained, It is identification information records; for each obtained identification information record, the identification information type is compared with the metadata structure vertex through the comparison function, that is:

[0051] in, It is Identification information record and metadata structure vertex The comparison function of It is The identification information type of each identification information record; If the comparison function The value of , it means that the identification information type comparison is successful, then Fill in the metadata structure vertex In the corresponding position, if the comparison function The value of , if the identification information type comparison fails, a new temporary metadata structure vertex is created to store the identification information record that failed the comparison; When adding an identification information record of an audio or video file to the metadata structure, select an identification information record whose attribute is an enumeration type. Conduct information review, including: The property is of enumeration type Identification information records, among which, The number of identification information records for attributes of enumeration type. Less than , the formula for information review is:

[0052] in, Is the first property of the enumeration type The review results of the identification information records, Is a collection of enumeration types in the metadata structure, Is the first in the enumeration type collection The identification information type of an identification information record; if If the value is 1, it means there are duplicate records and the information is reviewed. If the value is 0, it means that there are no duplicate records and the information review has not passed; Records of information identification that failed information review ,in, For the Information identification records that failed, Less than or equal to , filter similar information identification records in the metadata structure for replacement, that is:

[0053] in, It is The replacement result of the information identification record that failed, Is the enumeration type collection in the metadata structure and The information identification record with the greatest similarity, yes and the similarity measure of the information identifier records in the enumeration type collection, It is to select the information identification record with the largest similarity measurement value.

[0054] Working principle and its effect: The working principle and effect of a video and audio file security management system and method are as follows: After the camera captures the audio and video files, the encoding processing module first stores them in the buffer. During this process, the data buffer unit relies on an adaptive buffering strategy. Based on the transmission rate and data volume of the audio and video files transmitted by the camera, it continuously monitors the network bandwidth and changes in the number of file bytes. By setting time windows and sliding windows to count relevant data, the buffer occupancy rate and the length of data that can be continuously accommodated are calculated in combination with the evaluation interval. Then, a buffer status evaluation model is constructed to calculate the evaluation score, and the buffer capacity is dynamically adjusted based on the adjustment threshold to avoid data transmission problems. At the same time, the information embedding unit uses a deep fusion strategy to embed the source identification information into the file data structure and stores it in a secure storage area, thereby ensuring stable transmission and facilitating source tracing.

[0055] Then the key marking module comes into play. When the user plays or browses the audio and video files in the secure storage area, the tag collection unit monitors the key marking operation through the tag capture strategy, records the timestamp, configures the extraction interval to obtain the audio and video clips in the key interval, converts them into image frames, and then selects the key frames based on the motion change. Then, target recognition, audio data extraction and classification and other operations are performed to obtain key marking information. Then, the association fusion strategy of the index construction unit will define the metadata structure template based on this information and source identification information to construct a directed graph. In the process of processing new identification information records and reviewing enumeration type records, a multi-dimensional metadata structure positioning index is generated, which helps to accurately extract the key information that users are concerned about and realize the effective integration and association of multi-dimensional information, thereby improving file management and retrieval efficiency.

[0056] Finally, the security protection module operates. The key generation unit uses a feature fusion strategy to extract feature data from the metadata structure location index of the audio and video file to form an original feature set. The key material is generated through hash operation combined with a dynamic salt value, and then the initial encryption key is generated. The encryption execution unit determines the encryption level based on the adaptive encryption strategy and refers to the data volume and format of the audio and video file, and then performs hierarchical encryption. In this way, the dynamically updated encryption key and the adapted hierarchical encryption method are used to enhance the security of the audio and video file in the storage and other links, and prevent the data from being illegally obtained and tampered with. The overall system and method work together from multiple aspects such as data transmission, user interaction information integration, and data security assurance to effectively manage the entire life cycle of audio and video files and improve their use, management, and security protection levels.

[0057] The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A video and audio file security management system, characterized in that: Including coding processing module, key marking module and security protection module: The encoding processing module is used to store the video and audio files in the buffer when the camera captures the video and audio files, adjust the buffer capacity by monitoring the network bandwidth and the number of bytes of the video and audio files, and encode and embed the source identification information of the video and audio files in the buffer and store them in the secure storage area; The key mark module is used to monitor the key mark operation of the user when playing or browsing the audio and video files in the secure storage area, extract the audio and video segments in the key interval according to the key mark operation, use the motion change to screen the key frames and perform target recognition, extract audio data and classification to obtain the key mark information, and then define the metadata structure template according to the identification information to build a directed graph, and generate a multi-dimensional metadata structure positioning index by processing the newly added identification information records and reviewing the enumeration type records through the comparison function; The security protection module is used to encrypt the audio and video files in the secure storage area, generate an initial encryption key based on the metadata structure positioning index of the audio and video files, and determine the encryption level according to the data volume and format of the audio and video files, and encrypt the audio and video files in a hierarchical manner.

2. A video and audio file security management system as claimed in claim 1, characterized in that: The encoding processing module includes a data buffer unit and an information embedding unit; The data buffer unit is configured with an adaptive buffer strategy, which is used to adjust the buffer capacity in real time according to the transmission rate and data volume of the video and audio files transmitted by the camera, and to build a buffer state evaluation model by continuously monitoring the network bandwidth and the number of bytes of the video and audio files during the transmission of the video and audio files, and to evaluate the buffer state so as to dynamically allocate memory space as a buffer; The information embedding unit is configured with a deep fusion strategy, which is used to embed source identification information into the data structure of the video and audio file, and store the processed video and audio file in a secure storage area.

3. A video and audio file security management system as claimed in claim 2, characterized in that: The specific steps of the adaptive buffering strategy include: Set the initial buffer capacity and obtain the camera parameter information; Configure the time window and count the bytes of the audio and video files received within the time window; Configure a sliding window to track the long-term trend and short-term fluctuation of data traffic. Add the number of bytes of audio and video files counted in the time window to the sliding window data sequence, and remove the number of bytes of audio and video files counted in the earliest time window to keep the number of data points in the sliding window fixed. Configure the evaluation interval. At each evaluation interval, calculate the buffer occupancy rate based on the number of occupied buffer bytes and the buffer capacity, and calculate the length of time the buffer can continue to accommodate data. Evaluate the status of the buffer, build a buffer status evaluation model based on the buffer occupancy rate, the duration of data that can be continuously accommodated, and the network bandwidth, and calculate the buffer status evaluation score; Configure the adjustment threshold. If the buffer status evaluation score is less than the adjustment threshold, the buffer capacity increase operation is triggered; otherwise, no processing is performed.

4. A video and audio file security management system as claimed in claim 3, characterized in that: The buffer capacity increasing operation includes: Based on the number of bytes of the audio and video files in each sliding window data sequence, calculate the growth rate of the number of bytes in the sliding window; According to the growth rate of the number of bytes in the sliding window and the buffer occupancy rate, the buffer capacity is dynamically increased, that is: ； in, is the adjusted buffer capacity, is the buffer capacity, is the buffer occupancy, is the average growth rate of the number of bytes in the sliding window, and are the minimum and maximum thresholds for the growth rate of the number of bytes in the sliding window, is the buffer occupancy threshold, , and are all weighting coefficients.

5. The video and audio file security management system according to claim 1, characterized in that: The key point marking module includes a marking collection unit and an index building unit; The tag collection unit is configured with a tag capture strategy, which is used to monitor the key tag operation made by the user during the playback or browsing of the audio-visual file, select key frames through motion variation calculation, generate content summaries for key frame target recognition, extract and classify audio data, so as to identify and extract key tag information; The index construction unit is configured with an associated fusion strategy, which is used to index the key mark information and source identification information of the audio and video files, generate a multi-dimensional metadata structure positioning index according to a preset metadata structure template, add metadata structure identification information records through a comparison function, and perform information review on the enumeration type identification information records.

6. A video and audio file security management system as claimed in claim 5, characterized in that: The steps of the marking capture strategy include: When the user starts playing or browsing the video and audio files in the buffer, the focus marking operation is monitored and the focus marking type is identified; By monitoring the user's interactive behavior, the marking time point of the video and audio files where the key marks are located is recorded, and a timestamp is generated for each key mark; According to the key mark type, on the basis of each key mark timestamp, a mark extraction interval is configured, and according to the mark extraction interval, the video and audio clips of the key interval are obtained; Convert the audio and video clips in the key interval into a series of image frames, mark the first image frame as the key frame, configure the vector change threshold, and calculate the motion change of the image frame, that is: ； in, It is Image frames and Image frames The amount of movement change, is the image frame The middle position is The motion vector of is the image frame The middle position is The motion vector of If the amount of motion changes If it is greater than the vector change threshold, Marked as a keyframe, As the starting point, continue to calculate the adjacent motion changes Otherwise, skip , calculate the change in motion , until the traversal of the image frames of the video and audio clip is completed; Perform target recognition on key frames to obtain key mark information of key frames, including text information, target objects, and target scenes, and convert the key mark information recognition results of key frames into text descriptions as content summaries; Extract audio data from audio and video clips in key intervals, identify key tag information of the audio data, classify the audio data, and identify the emotional color of the audio data.

7. A video and audio file security management system as claimed in claim 5, characterized in that: The steps of associating the fusion strategy include: Define a metadata structure template according to the identification information, define the metadata structure as a directed graph, and define an attribute type for each vertex of the metadata structure, the attribute type includes an enumeration type, a string type, and an array type; Obtain identification information records of the video and audio files, and for each obtained identification information record, compare the identification information type with the metadata structure vertex through a comparison function, construct a comparison function between the identification information record and the metadata structure vertex, and query whether there is an identification information type that is the same as the identification information record in the metadata structure vertex; If there is an identification information type that is the same as the identification information record, it means that the identification information type comparison is successful, and the identification information record is filled in the position corresponding to the metadata structure vertex of the same identification information type. If there is no identification information type that is the same as the identification information record, the identification information type comparison fails, and a new temporary metadata structure vertex is created to store the identification information record that failed the comparison.

8. The video and audio file security management system as claimed in claim 5, characterized in that: The step of associating the fusion strategy also includes: When a new identification information record of an audio-visual file is added to the metadata structure, an identification information record with an attribute of an enumeration type is selected for information review to query whether the identification information record of the enumeration type exists in the enumeration type set in the metadata structure; If the identification information type of the existing identification information record is found to be the same as the information type of the identification information record of the newly added audio-visual file in the enumerated type set in the metadata structure, the information review is passed, otherwise the information review is not passed; For information identification records that fail the information review, similar information identification records in the metadata structure are screened and replaced; Calculate the similarity measure between the information identification record that fails the information review and the information identification record of the same information type in the enumeration type set, select the information identification record with the largest similarity measure in the enumeration type set in the metadata structure, and replace the identification information record of the newly added audio and video file.

9. The video and audio file security management system according to claim 1, characterized in that: The security protection module includes a key generation unit and an encryption execution unit; The key generation unit is provided with a feature fusion strategy, which is used to generate an encryption key with dynamic update characteristics for the video and audio files, by extracting feature data from the metadata structure positioning index of the video and audio files to form an original feature set, and generating key materials after hashing the original feature set, and using the key materials as input to generate an initial encryption key; The encryption execution unit is configured with an adaptive encryption strategy, which is used to perform hierarchical encryption on audio and video files according to an initial encryption key, determine the encryption level by evaluating the data volume and format of the audio and video files, and adaptively encrypt the audio and video files according to the encryption level.

10. A method for managing video and audio files safely, which is implemented based on a video and audio file safety management system according to any one of claims 1 to 9, characterized in that: The following steps are involved: Step S1: When the camera captures an audio and video file, the audio and video file is stored in a buffer, the buffer capacity is adjusted by monitoring the network bandwidth and the number of bytes of the audio and video file, and the source identification information of the audio and video file in the buffer is encoded and embedded and then stored in a secure storage area; Step S2: by monitoring the key marking operation of the user when playing or browsing the audio and video files in the secure storage area, extracting the audio and video segments of the key interval according to the key marking operation, using the motion variation to screen the key frames and perform target recognition, extracting audio data and classification, so as to obtain the key marking information, and then defining the metadata structure template according to the identification information to construct a directed graph, and processing the newly added identification information records and reviewing the enumeration type records through the comparison function to generate a multi-dimensional metadata structure positioning index; Step S3: Encrypt the audio and video files in the secure storage area, generate an initial encryption key based on the metadata structure positioning index of the audio and video files, determine the encryption level according to the data volume and format of the audio and video files, and encrypt the audio and video files in a hierarchical manner.

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