KR102146459B1 - Method for extracting cctv image data in the unallocated area based on informal xfs file system and apparatus thereof - Google Patents

Abstract

The present invention relates to a method and apparatus for extracting CCTV image data in an unallocated area based on an unstructured XFS file system.
According to the present invention, in an apparatus for extracting CCTV image data based on an unstructured XFS file system, a superblock search unit that detects a location where an XFS signature is stored by searching for a superblock included in an allocation group, and an unstructured XFS file system An information analysis and file extracting unit for analyzing information and extracting a file for each of the allocated and non-allocated areas, and an image data extracting unit for extracting CCTV image data from data stored in the extracted non-allocated area.
As described above, according to the present invention, in a CCTV video recorder using an unstructured XFS file system, by using a method of searching and analyzing the superblock and alignment group data of the XFS file system, in particular, CCTV image data stored in an unallocated area. You can find and extract it.
In addition, according to the present invention, not only in a single XFS partition, but also in an XFS partition mixed with MBR and GPT, a superblock can be searched to distinguish an allocated area and an unallocated area, and image data stored in each area can be extracted.

Description

CCTV image data extraction method and device in unallocated area based on unstructured XFS file system {METHOD FOR EXTRACTING CCTV IMAGE DATA IN THE UNALLOCATED AREA BASED ON INFORMAL XFS FILE SYSTEM AND APPARATUS THEREOF}

The present invention relates to a method and apparatus for extracting CCTV image data in an unallocated area based on an unstructured XFS file system, and more particularly, to extract CCTV image data stored in an unallocated area in an unstructured XFS file system. It relates to a method and apparatus for extracting CCTV image data.

Recently, as the quality of CCTV video has improved from SD (Standard Definition) to HD (High Definition), the size of CCTV video data has increased. For this reason, it is difficult to store and manage HD video with the existing embedded file system. As it became difficult, the XFS file system, which is specialized for processing large files and fast processing speed among standard file systems, was used.

Currently, CCTV systems mainly use a method of storing recorded video data using DVR or NVR, which is a video recorder, and products that use XFS, a Linux-based file system, are increasing to effectively store and manage HD video. have. However, when CCTV video recorder manufacturers use an atypical XFS file system optimized for HD video data recording instead of the standard XFS file system, there is a situation in which CCTV video data saved by a video recorder cannot be checked by a general method that can be used on a computer. Occurs.

Even if you check the video on the CCTV video recorder, you can check only the video data stored in the allocated area. Using UFS Explorer, a software for porting the Linux file system to Windows, is saved in the allocated area in the video recorder using the unstructured XFS file system. Although it is possible to extract image data, it is also impossible to extract image data stored in the unallocated area in this method.

In addition, in the existing single XFS, since the superblock is located at LBA 0, it is easy to identify, but there is a problem in that it is difficult to identify the location information of the superblock in the recent MBR and GPT based XFS system.

The technology behind the present invention is disclosed in Korean Patent Application Publication No. 2015-0074533 (published on July 02, 2015).

The technical problem to be achieved by the present invention is to provide a method and apparatus for extracting CCTV image data in an unallocated area based on an unstructured XFS file system that can extract CCTV image data stored in an unallocated area even in an unstructured XFS file system. It is to do.

According to an embodiment of the present invention for achieving such a technical problem, in an apparatus for extracting CCTV image data based on an unstructured XFS file system, a super block that searches for a super block included in an allocation group and detects a location where an XFS signature is stored. Block search unit, information analysis and file extraction unit that analyzes information for each of the allocated and unallocated areas of the unstructured XFS file system and extracts files, and a video that extracts CCTV video data from data stored in the extracted non-allocated areas It includes a data extraction unit.

The superblock search unit analyzes the MBR area of the unstructured XFS file system to determine whether an XFS signature exists in the MBR area, and if there is an XFS signature in the MBR area, the superblock search is terminated by determining that the entire area is composed of a single partition. And, if the XFS signature does not exist in the MBR area, it is determined that it has been divided into a plurality of partitions, the number of partitions can be checked from the MBR partition information, and the XFS signature can be sequentially searched for each of the plurality of partitions.

The information analysis and file extraction unit generates a file list by analyzing root node data and inode data of the allocated area, and analyzes the inode information of the selected file when a file to be extracted is selected. You can extract the file data stored in the location.

The information analysis and file extraction unit analyzes the B tree data for the unallocated area, and determines the generation time of the last frame of the nth file of the non-allocated area and the generation time of the first frame of the n+1th file that are stored discontinuously. The time difference is compared with the threshold value, and if the time difference is less than the preset threshold, connection information for the unallocated area is generated, and then data is extracted in the form of a single file according to the connection information, and the time difference is a preset threshold. If the value is more than the value, it can be extracted in the form of multiple files for each unallocated area.

The image data extraction unit generates a file list for a single file or multiple files for an unallocated area, analyzes the file data in the order of the generated list to determine whether image data can be extracted, and when image data extraction is possible The video frames are listed as I-frames, which are reference video information, and P-frames, which are changed video information, and the connection information between frames is analyzed to determine whether video frames can be connected. If video frames are connected, the video frames are reconstructed. When it is extracted as a video file and it is impossible to connect the video frame, only the I frame, which is the reference video information, may be extracted among the video frames and then extracted as an individual image file.

According to another embodiment of the present invention, in a method for extracting CCTV image data based on an unstructured XFS file system using a CCTV image data extraction device, a superblock included in an allocation group is used to detect a location where an XFS signature is stored. Searching, analyzing information on each of the allocated and unallocated areas of the unstructured XFS file system and extracting files, and extracting CCTV image data from data stored in the extracted non-allocated areas.

As described above, according to the present invention, a CCTV video recorder using an unstructured XFS file system uses a method of searching and analyzing the superblock and allocation group data of the XFS file system, and in particular, CCTV image data stored in an unallocated area. You can find and extract it.

In addition, according to the present invention, not only in a single XFS partition, but also in an XFS partition mixed with MBR and GPT, a superblock can be searched to divide an allocated area and an unallocated area, and image data stored in each area can be extracted.

In addition, according to the present invention, it is possible to more effectively identify the location information of the superblock in the XFS system configured based on MBR and GPT. In addition, when data stored in an unallocated area is extracted using an allocation group data analysis algorithm, it is possible to separate and extract data into individual areas or entire areas.

1 is a diagram for describing a basic structure of an XFS file system.
2 is a block diagram of an apparatus for extracting CCTV image data according to an embodiment of the present invention.
3 is a flowchart illustrating a method of extracting image data of a CCTV image data extracting apparatus according to an embodiment of the present invention.
FIG. 4 is a flowchart illustrating step S310 of FIG. 3.
5 is a flowchart illustrating step S320 of FIG. 3.
6 is a flowchart illustrating step S330 of FIG. 3.
7 is an exemplary diagram showing that non-allocated areas are discontinuously allocated.
FIG. 8 is a flowchart illustrating step S340 of FIG. 3.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In this process, the thickness of the lines or the size of components shown in the drawings may be exaggerated for clarity and convenience of description.

In addition, terms to be described later are terms defined in consideration of functions in the present invention, which may vary according to the intention or custom of users or operators. Therefore, definitions of these terms should be made based on the contents throughout the present specification.

First, an image alignment apparatus using a time stamp according to an embodiment of the present invention will be described with reference to FIG. 1.

1 is a diagram for describing a basic structure of an XFS file system.

In the case of the basic structure diagram of the XFS file system shown in FIG. 1, the unstructured XFS file system used in CCTV also has the same structure.

As shown in Fig. 1, the XFS file system divides and manages one partition into an allocation group, an allocation area, and each allocation group consists of a plurality of blocks, of which the first block is The Allocation Group Header is located.

In addition, the Allocation Group Header is composed of a plurality of sectors, of which the first sector is composed of a Super Block.

Here, the super block is a block that is located at the very beginning of each allocation group, is a block that can confirm that it is an XFS file system, and has information about all allocation areas. Therefore, by searching the location of the superblock and analyzing the contents of the superblock, it is possible to identify the allocated and unallocated areas of the XFS file system.

2 is a block diagram of an apparatus for extracting CCTV image data according to an embodiment of the present invention.

As shown in FIG. 2, the CCTV image data extraction apparatus 200 according to the embodiment of the present invention includes a superblock search unit 210, an information analysis and file extraction unit 220, and an image data extraction unit 230. .

3 is a flowchart illustrating a method of extracting image data of a CCTV image data extracting apparatus according to an embodiment of the present invention.

In more detail, FIG. 3 is a flowchart illustrating a superblock and allocation group data analysis algorithm of an unstructured XFS file system and a method of extracting image data from an allocated area and an unallocated area.

First, the superblock search unit 210 searches for a superblock in the unstructured XFS file system and checks a location where information of the XFS file system is stored (S310).

Here, the information of the XFS file system includes the XFS signature.

Next, the information analysis and file extraction unit 220 analyzes information on each of the allocated area and the non-allocated area of the unstructured XFS file system and extracts a file (S320 and S330).

That is, since the information analysis and file extraction of the unstructured XFS file system is divided into a data allocation area and a non-allocated area, the information analysis and file extraction unit 220 analyzes and analyzes information for each of the allocated area and the non-allocated area. Let's extract the file.

Finally, the image data extracting unit 230 extracts CCTV image data of the unallocated area (S340).

Hereinafter, each step shown in FIG. 3 will be described in detail with reference to FIGS. 4 to 8.

FIG. 4 is a flowchart for explaining step S310 of FIG. 3, and is a flowchart for searching a superblock of an unstructured XFS file system.

The superblock search unit 210 analyzes the master boot record (“MBR” hereinafter) of the unstructured XFS file system (S311).

MBR corresponds to LBA0 and means start information for booting. That is, the MBR is a start-up area recorded at the front of the hard disk, and when power is applied to the PC, the program recorded in the MBR of the first hard disk is read. The MBR program read in this way reads the boot sector of the partition starting from the information in the partition table (the part where the OS startup program at the beginning of the partition is recorded), and the read The OS is started by the program of the sector.

Then, the superblock search unit 210 checks whether the XFS signature exists in the MBR area of the unstructured XFS file system (S312).

If an XFS signature exists in the MBR area, the superblock search unit 210 determines that the unstructured XFS file system is an unstructured XFS file system using a single partition for the entire hard disk area, and ends the superblock search ( S313).

However, if the XFS signature does not exist in the MBR area, the superblock search unit 210 analyzes the MBR partition information to check the number of partitions (S314).

That is, if the XFS signature does not exist in the MBR area, the superblock search unit 210 determines that the hard disk is divided into a plurality of partitions, and checks the number of partitions from the MBR partition information.

For example, when the entire area is divided into single or n partitions, the MBR and the XFS file system are used in combination, the GUID Partition Table (GPT) and the XFS file system are used in combination, the MBR and Since the GPT and the XFS file system may be used in combination, the superblock search unit 210 analyzes the MBR partition information to check the number of partitions.

Next, the superblock search unit 210 searches for an XFS signature through a sequential scan process for each of the plurality of partitions (S315).

If the number of the identified partitions is n, the superblock search unit 210 moves to the start position of the 0 th partition and then checks whether the XFS signature exists. If the XFS signature does not exist at the start position, the XFS signature is checked through sequential search that searches for the XFS signature while increasing the sector.

When the XFS signature is confirmed through such a scan process, the superblock search unit 210 moves to the next partition location and repeats the same search process.

In this way, when all the positions of the superblocks for n partitions are confirmed, the superblock search unit 210 moves to step S313 to end the superblock search.

5 is a flowchart for explaining step S320 of FIG. 3, which is a flowchart for analyzing information on an allocated area and extracting a file.

First, the information analysis and file extraction unit 220 analyzes the root node data and inode data of the allocated area (S321), and then generates a file list (S322).

Here, the root node means the top node in the hierarchical tree that does not have a parent node, and the inode is a data structure used in a traditional Unix-like file system such as UFS. Etc. Contains information about the file system.

Each file has one inode, and the inode has an owner group, access mode (read, write, execute permission), file type, and inode number (inode number, i-number, i-number), etc. I have information. Therefore, files in the file system can be identified through a unique inode number.

Next, when a file to be extracted from the user is selected (S323), the information analysis and file extraction unit 220 analyzes the inode information of the selected file (S324), and the file data stored in the corresponding location Is extracted (S325).

6 is a flowchart for explaining step S330 of FIG. 3, a flowchart illustrating information analysis and file extraction of a non-allocated area, and FIG. 7 is an exemplary diagram showing that non-allocated areas are discontinuously allocated.

First, the information analysis and file extraction unit 220 analyzes B tree data for an unallocated area (S331).

Here, the B tree data is a multi-directional search tree, meaning a tree-type data structure or table information designed to efficiently search and update large files.

Next, the information analysis and file extraction unit 220 compares the time difference between the generation time of the last frame of the nth file of the non-allocated area stored discontinuously and the generation time of the first frame of the n+1th file with the threshold value. Do (S332).

That is, as shown in FIG. 7, there are many cases where a moving picture file is divided into an unallocated area and discontinuously allocated and stored. Therefore, in the case of continuously photographed CCTV images, even if they are stored in an unallocated area, it is preferable to extract them as a single file, and in the case of discontinuously photographed CCTV images, it is preferable for data management to extract them as multiple files.

Therefore, the information analysis and file extraction unit 220 checks the generation time of the last frame of the nth file of the unallocated area and the generation time of the first frame of the n+1th file through B tree data, and the time difference is If it is less than the set threshold, it is determined as a CCTV image continuously photographed. Then, the information analysis and file extraction unit 220 generates connection information for the unallocated area as shown in FIG. 7 (S333), and then extracts data in the form of a single file according to the connection information (S334).

And, if the time difference between the generation time of the last frame of the nth file of the unallocated area and the generation time of the first frame of the n+1th file is greater than or equal to a preset threshold, it is determined as a discontinuously photographed CCTV image. After generating a list of discontinuous regions for the allocated regions (S335), a file for each discontinuous region is generated for each non-allocated region (S336).

In addition, the information analysis and file extraction unit 220 extracts data from a corresponding region and stores the data in the form of multiple files (S337).

As described above, according to an embodiment of the present invention, the information analysis and file extraction unit 220 determines whether to extract data of a non-allocated area located discontinuously as a single file or as an individual file to generate and extract a file. Stored data.

FIG. 8 is a flowchart for explaining step S340 of FIG. 3, and is a flowchart for extracting image data of an unallocated area.

In the case of the allocated area, the extracted CCTV image data can be reproduced using a dedicated program provided to the CCTV manufacturer, so it is not necessary to separately extract the image data, but in the case of data extracted from the unallocated area, a dedicated program provided by the CCTV manufacturer Since it cannot be played back, a separate image data extraction operation is required.

In order to extract image data from the unallocated area, the image data extracting unit 230 first generates a list of files extracted from the unallocated area (S341).

That is, the image data extracting unit 230 generates a file list for a single file or multiple files for the unallocated area extracted in step S330.

Then, the image data extraction unit 230 analyzes the file data in the order of the generated list, checks whether there is image frame information in the file (S342), and determines whether image data can be extracted (S343).

That is, the image data extraction unit 230 checks the data of the extracted unallocated file, and checks whether there is normal image frame information in the file data. If there is even one image frame structure in the unallocated file, since data can be obtained from the file, the process moves to step S344.

As a result of the determination, when it is impossible to extract image data or if there is no image data, the image data extraction unit 230 ends the image data extraction operation and proceeds with the next file.

If it is possible to extract the image data, the image data extraction unit 230 performs an image frame search (S344), and lists the image frames into an I frame as reference image information and a P frame as change image information (S345), The connection information of each frame is analyzed (S346).

The image data extracting unit 230 determines whether connection of image frames is possible through analysis of connection information between frames (S347).

The video frame is composed of metadata information and video data added by a CCTV recorder, and the metadata information includes information on the properties of the video data (I/P frames), time information and video sequence of the video. .

Accordingly, the image data extracting unit 230 determines whether the image data can be combined using the attribute information of the image data and information about the time and the order of the images.

As a result of the determination, if the image frame connection is possible, the image data extracting unit 230 reconstructs the image frame and extracts it as a moving image file (S348). If the image frame connection is impossible, the image data extracting unit 230 performs a reference image among the image frames. After extracting only the information I frame, it is extracted as an individual image file (S349).

As described above, according to an embodiment of the present invention, a CCTV video recorder using an unstructured XFS file system searches for and analyzes the superblock and alignment group data of the XFS file system. You can find and extract CCTV video data.

In addition, according to an embodiment of the present invention, a superblock is searched not only in a single XFS partition, but also in an XFS partition mixed with MBR and GPT to distinguish an allocated area and an unallocated area, and to extract image data stored in each area. I can.

In addition, according to an embodiment of the present invention, it is possible to more effectively identify the location information of the superblock in an XFS system configured based on MBR and GPT. In addition, when data stored in an unallocated area is extracted using an allocation group data analysis algorithm, it is possible to separate and extract data into individual areas or entire areas.

The present invention has been described with reference to the embodiments shown in the drawings, but these are only exemplary, and those of ordinary skill in the art will understand that various modifications and equivalent other embodiments are possible therefrom. will be. Therefore, the true technical protection scope of the present invention should be determined by the technical idea of the following claims.

200: CCTV image data extraction device 210: Super block search unit
220: information analysis and file extraction unit 230: image data extraction unit

Claims (10)

In the CCTV image data extraction device based on the unstructured XFS file system,
A superblock search unit that searches for a superblock included in the allocation group and detects the location where the XFS signature is stored,
An information analysis and file extraction unit that analyzes information and extracts files for each of the allocated and unallocated areas of the unstructured XFS file system, and
It includes an image data extracting unit for extracting CCTV image data from the data stored in the extracted unallocated area,
The superblock search unit,
Analyze the MBR area of the unstructured XFS file system to determine whether an XFS signature exists in the MBR area,
If there is an XFS signature in the MBR area, it is determined that the entire area is composed of a single partition, and the superblock search is terminated.
CCTV image data extraction device that determines that the XFS signature does not exist in the MBR area, determines that it has been divided into a plurality of partitions, checks the number of partitions from the MBR partition information, and sequentially searches for the XFS signature for each of the plurality of partitions. delete The method of claim 1,
The information analysis and file extraction unit,
The file list is created by analyzing the root node data and inode data of the allocated area, and when the file to be extracted is selected, the inode information of the selected file is analyzed and the file data stored in the corresponding location CCTV image data extraction device to extract. The method of claim 1,
The information analysis and file extraction unit,
Analyze the B tree data for the unallocated area,
Compare the time difference between the creation time of the last frame of the nth file of the non-allocated area stored discontinuously and the creation time of the first frame of the n+1th file with the threshold value,
If the time difference is less than a preset threshold, connection information for the unallocated area is generated, and then data is extracted in the form of a single file according to the connection information.
A CCTV video data extraction device that extracts multiple files for each unallocated area when the time difference is greater than or equal to a preset threshold. The method of claim 4,
The image data extraction unit,
Create a file list for a single file or multiple files for an unallocated area, analyze the file data in the order of the created list to determine whether image data can be extracted,
If video data can be extracted, list up the video frames as I frames, which are reference video information, and P frames, which are change video information,
It determines whether video frames can be connected through analysis of connection information between frames,
A CCTV video data extraction device that reconstructs an image frame when it is possible to connect it and extracts it as a video file. When it is not possible to connect an image frame, it extracts only the I frame, which is the reference image information, and then extracts it as an individual image file. In a CCTV image data extraction method based on an unstructured XFS file system using a CCTV image data extraction device,
Searching for a superblock included in the allocation group to detect the location where the XFS signature is stored,
Analyzing information and extracting files for each of the allocated and unallocated areas of the unstructured XFS file system, and
Comprising the step of extracting CCTV image data from the data stored in the extracted unallocated area,
The step of searching for the superblock,
Analyzing the MBR area of the unstructured XFS file system and determining whether an XFS signature exists in the MBR area,
If there is an XFS signature in the MBR area, it is determined that the entire area is composed of a single partition, and the superblock search is terminated, and
If the XFS signature does not exist in the MBR area, it is determined that it has been divided into a plurality of partitions, the number of partitions is checked from the MBR partition information, and a CCTV image including the step of sequentially searching the XFS signature for each of the plurality of partitions. Data extraction method. delete The method of claim 6,
Analyzing the information and extracting the file,
Analyzing the root node data and inode data of the allocated area to create a file list, and
When a file to be extracted is selected, a method for extracting CCTV image data comprising the step of analyzing the inode information of the selected file and extracting the file data stored in the corresponding location. The method of claim 6,
Analyzing the information and extracting the file,
Analyzing B tree data for unallocated areas,
Comparing the time difference between the generation time of the last frame of the nth file of the non-allocated area stored discontinuously and the generation time of the first frame of the n+1th file with a threshold value, and
If the time difference is less than the preset threshold, connection information for the unallocated area is generated, and data is extracted in the form of a single file according to the connection information. If the time difference is more than a preset threshold, each unallocated area is CCTV image data extraction method comprising the step of extracting in the form of multiple files. The method of claim 9,
The step of extracting the image data,
Generating a file list for a single file or multiple files for an unallocated area,
Analyzing the file data in the order of the generated list to determine whether image data can be extracted,
If image data extraction is possible, listing the image frames into I frames as reference image information and P frames as change image information,
Determining whether video frames can be connected through analysis of connection information between frames, and
CCTV video data extraction method including the step of extracting only I-frames, which are reference video information among video frames, by reconfiguring and extracting video frames when video frame connection is possible, and extracting into individual image files when video frame connection is not possible .

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