KR20190061549A - File system and method of storing files based on the file system - Google Patents

Abstract

The present invention relates to a file system and a file storing method based on the same. According to the present invention, the file system divides a file storage region to correspond to concurrently storable image data streams one by one. The file storing method based on the file system sets each of divided storage regions of the file storage region to correspond to a concurrently storable image data stream one by one, wherein a maximum of only one file is recorded in each divided storage region concurrently to enable each file to be stored at continuous clusters of the storage region. Thereby, the present invention can minimize an FAT update overhead to reduce update costs and minimize an abused file system space as well as enhance reliability.

Description

[0001] The present invention relates to a file system and a file storing method using the file system,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a file storage method and a file system for a video storage device such as a vehicle black box system or a multi-channel closed circuit TV, and more particularly, to a file storage system compatible with a conventional file system such as a FAT 32 file system A new file system that improves recording performance while improving reliability, and a file storage method using the file system.

Microsoft's FAT32 file system has been the main file system for automotive black box systems. This is because the FAT32 file system is virtually license-free, so development companies can use it for free, and memory cards, which are mainly used as storage devices for car black boxes, are basically available in the FAT32 file system format. For reference, a memory card with a capacity of 64 GB or more is available as an exFAT file system format.

In the present invention, a FAT32 file system, which is most used in a vehicle black box file system, will be described as an embodiment. However, it should be noted that the present invention can be applied not only to the FAT32 file system but also to other existing file systems such as an exFAT file system.

1 is a structural view showing the basic structure of a FAT32 file system of Microsoft Corporation.

Referring to FIG. 1, the FAT32 file system of Microsoft Corporation divides the entire file system space into clusters each having a predetermined size, and uses the divided file system as a basic unit of allocation. For example, if the size of a cluster is 32 KB, then all 32 GB memory cards will have 1M (= 1024 x 1024) clusters. The cluster allocation information is stored and managed in a file system management data structure called a FAT (File Allocation Table) table. One entry in the FAT table is 4 bytes in size and the number of entries is equal to the total number of clusters in the file system.

Like other file systems, the FAT32 file system also supports a tree-like directory structure. There is a root directory in cluster # 2, and you can create files or subdirectories in this root directory. A directory is composed of directory entries having a size of 32 bytes, each directory entry having information on one file or subdirectory.

One of the information recorded in this directory entry is the number of the first cluster allocated to the file. The second cluster number can be checked on the FAT table. When the FAT table is looked up using the cluster number as an index, the value stored in the accessed FAT entry is the number for the next cluster. In this way, the cluster information assigned to the file can be tracked in a chain, which is stored in the FAT table, so this is called the FAT chain. If the value stored in the FAT entry is 0x0FFFFFF8 or more, this means the end of the FAT chain (END), meaning that there are no more clusters allocated to the file. If the FAT entry has an initial value of 0x00000000, it indicates that the cluster is unused, which is not yet allocated.

If a file is still allocated to contiguous clusters, then the FAT chain is also contiguous. For example, if a file is allocated 5 clusters consecutively starting from 1000 clusters, the FAT chain will have the form 1000 → 1001 → 1002 → 1003 → 1004 → END. On the other hand, if the unused clusters are not clustered and scattered around, the files may not be allocated to successive clusters.

Thus, when unused clusters are not clustered and scattered around, this is referred to as file system fragmentation. This file system fragmentation becomes worse the longer the file system is used. Therefore, clusters are allocated to non-contiguous clusters such as 1000 → 2122 → 3080 → 4305 → 5202 → END, rather than being allocated consecutively as in the above example.

If the FAT chain is non-contiguously constructed because the files are not allocated to successive clusters, there arises a problem that the FAT table update overhead becomes large. For example, when the clusters allocated to one file are consecutively allocated and the FAT chain is formed as 1000 → 1001 → 1002 → 1003 → 1004 → END, in order to store this information in the FAT table, one FAT sector (FAT The sector including the corresponding FAT entries in the table). On the other hand, if clusters allocated to one file are allocated discontinuously and all the clusters are scattered so that the FAT chain is formed as 1000 → 2122 → 3080 → 4305 → 5202 → END, in order to store this information in the FAT table, You need to update the five FAT sectors that contain FAT entries.

If the number of FAT table updates is increased, the following problems arise.

(1) Since the number of times of writing to the disk increases, performance deterioration occurs. Particularly, in the case of a memory card mainly used for storage in a vehicle black box system, a frequent write operation in a small unit such as a sector (512 bytes) causes a more serious performance degradation phenomenon.

(2) There is a high possibility that the file system is damaged. The meta-data, that is, the FAT table and directory, must be maintained in consistency for management of the FAT32 file system. However, if the power is suddenly lost while the metadata is being updated, or if the user pulls out the memory card, some of them are stored and some are not stored, which results in inconsistency of the file system. This corruption of the file system may cause some files to be lost or even the file system itself not to be recognized at a later time. As the number of FAT table updates increases, the probability of exposure to these risks increases.

Because of these risks, there have been various attempts to use a different file system instead of the existing FAT32 file system. Here, other file systems are file systems that are incompatible with FAT32 and are designed specifically for black boxes. A typical example is the TAT (Time Allocation Table) file system. The TAT file system described above is characterized by minimizing the possibility of file system corruption by simplifying time-sequential data to be allocated to contiguous space on the file system as well. However, this method has a large disadvantage that it is incompatible with the FAT32 file system. That is, since it is not compatible with the FAT32 file system, it is inconvenient to separately install a dedicated video player in a PC in order to reproduce a black box image stored by a file system of the above-described method on a PC.

In this respect, there has been an attempt to improve the existing FAT32 file system to the extent that it maintains compatibility with the FAT32 file system, which is generally widely used. A typical example is to pre-create files of a certain size so that the file system space is completely filled. FIG. 8 is an exemplary diagram illustrating a state in which one storage area is divided into a predetermined size and one file is recorded in each divided area according to this conventional technique. According to this method, when new video data is recorded, the oldest file is selected with a predetermined size, and the file name is changed and new data is recorded in the already allocated cluster. As a result, since only the directory entry is changed and the FAT table is not changed at all in the meta data of the file system, the possibility of damaging the file system can be reduced. However, as shown in FIG. 8, since the size of the actually encoded image data may vary greatly even for a certain amount of time, it is possible to fill the file allocation space of a predetermined size almost have. As a result, there is a disadvantage that a small portion of the entire file system space can be wasted.

In summary, a conventional file system for a vehicle black box system can be roughly divided into two types. One is a dedicated file system for the black box system, which provides high reliability but is incompatible with the FAT32 file system, so it is inconvenient to install a dedicated image player in order to check the image on the PC. The other is to preserve the FAT32 file system for compatibility. To improve reliability, all files are preallocated. However, there are additional problems such as wasting file system space.

Korean Patent Registration No. 10-1370503 Korean Patent Laid-Open Publication No. 10-2013-0071850

It is an object of the present invention to solve the above-described problems and to provide an optical disk apparatus which is compatible with an existing FAT 32 file system or an exFAT file system and minimizes the overhead of FAT table update of the file system, File system.

Another object of the present invention is to provide a file storage method based on the above-described file system.

According to an aspect of the present invention, there is provided a method of storing a file in a file storage device capable of storing one or more video data streams, the method comprising the steps of: (a) (FAT) area, a root directory area, and a file storage area, the file storage area including a system storage area and a predetermined number of Formatting and initializing the file system into a file system characterized by including divided storage areas; (b) designating a predetermined divided storage area corresponding to the file name in the file storage area when a new file recording request is made with the file name, checking the unused space of the designated divided storage area, Allocating a contiguous space of a predetermined size to the FAT table and updating the FAT table; (c) recording actual file data in the allocated space; (d) when recording the file data is completed, returning the unused space among the allocated spaces and updating the FAT table; Wherein the divided storage areas of the file storage area correspond to one-to-one correspondence with image data streams that can be simultaneously stored in the file storage device, and each of the divided storage areas corresponds to one of the simultaneously- And the system storage area of the file storage area records information on the divided storage areas.

In the file storage method according to the first aspect, it is preferable that the file name provided in the file write request in the step (b) includes information on a channel and information on a video data stream type.

In the file storage method according to the first aspect, it is preferable that the size of the contiguous space allocated in response to the file write request in the step (b) is a maximum possible size of the file requested to be recorded.

In the file storage method according to the first aspect, it is preferable that when a new file write request is generated in the step (b), only one file is simultaneously recorded in one divided storage area.

In the file storage method according to the first aspect, in the allocating of the consecutive space of a predetermined size to the identified unused space in the step (b), a continuous free space of the predetermined size If there is no existing space, deleting the oldest file in the designated divided storage area to acquire additional unused space, and sequentially allocating a continuous space of a predetermined size from the unused space and the additional unused space in which the file is deleted .

In the file storage method according to the first aspect, the information on the divided storage areas recorded in the system storage area of the file storage area may include a number of divided storage areas, position information of each divided storage areas, Size information of the regions, and information on a video data stream type set to be one-to-one correspondence to each divided storage areas.

In the file storage method according to the first aspect, the file storage method is applied to a file storage device of a car black-box system having one or two cameras, and one Or two or more video data stream types are provided.

In the file storage method according to the first aspect, the file storage method is preferably applied to a file storage device of a closed circuit television (CCTV) system having one or two cameras.

A file system according to a second aspect of the present invention relates to a file system of a file storage device capable of storing one or two image data streams, the file system comprising: a PBR (Partition Boot Record) area in which information about a file system is stored; A first FAT area storing a file allocation table (FAT) including cluster allocation information; The second FAT area in which a restoration FAT for the file allocation table is stored; A root directory area in which directory entries are stored; And a file storage area including a predetermined number of divided storage areas and a system storage area,

The divided storage areas of the file storage area correspond to one-to-one correspondence with image data streams that can be simultaneously stored in the file storage device, and each of the divided storage areas is designated to correspond one-to-one with one of the simultaneously stored image data streams , The system storage area of the file storage area records information on the divided storage areas.

In the file storage method according to the second aspect, the information on the divided storage areas recorded in the system storage area of the file storage area may include the number of divided storage areas, the location information of each divided storage areas, Size information of the regions, and information on a video data stream type set to be one-to-one correspondence to each divided storage areas.

In the file storage method according to the second aspect, it is preferable that at most one file is simultaneously recorded in each divided storage area included in the file storage area.

The file system and the file storing method according to the present invention are fully compatible with the conventional FAT32 file system or the exFAT file system so that a memory card as a file storage device can be inserted into a PC or a smart phone, . ≪ / RTI >

Also, the file system and file storage method according to the present invention can improve the reliability by complementing low reliability of existing file systems. In other words, the existing FAT32 file system or exFAT file system may be damaged when the power supply is interrupted while updating the metadata such as the FAT table, or when the memory card is removed, some are stored and some are not stored Has occurred. However, the file storage method according to the present invention improves the FAT table update method by allocating successive clusters to one file, and as a result, the possibility of damaging the file system can be greatly reduced.

In addition, the file system and the file storage method according to the present invention can improve the recording performance of the file system by improving the metadata (i.e., FAT table) update performance of the file system.

In addition, the file system and the file storage method according to the present invention enable the file system space to be efficiently used without waste, compared with the conventional file system. The conventional methods of improving the FAT32 file system have a problem that some file system space is not used and is wasted. However, through the present invention, the reliability of the FAT32 file system or the exFAT file system can be compensated for, but the wasted file system space can be minimized.

Therefore, when the file system and the file storage method according to the present invention having the above-described effects are applied to a file storage device of a vehicle black box system, an improvement effect can be expected in terms of reliability, recording performance, and efficient use of storage space . Particularly, the improvement effect is more significant because it is provided in a state of maintaining 100% compatibility with the FAT32 or exFAT file system format which is basically applied to a commercially available memory card.

1 is a structural view showing the basic structure of a FAT32 file system of Microsoft Corporation.
2 is a structural view illustrating a structure of a file system according to a preferred embodiment of the present invention.
FIG. 3 is a flowchart sequentially illustrating a file storing method according to a preferred embodiment of the present invention.
4 is a diagram illustrating a process of allocating a space in advance according to a request for recording a new file in a file storage method according to a preferred embodiment of the present invention.
5 is a diagram illustrating a process of recording data in a file space allocated in advance in a file storage method according to a preferred embodiment of the present invention.
FIG. 6 is an exemplary diagram illustrating a process of returning an unused allocated space after completing file recording in the file storing method according to the preferred embodiment of the present invention.
FIG. 7 is an exemplary diagram illustrating a file arrangement state after five files are recorded in one storage area in a file storage method according to a preferred embodiment of the present invention. FIG.
8 is an exemplary diagram illustrating a state in which a file storage area is divided into a predetermined size and then one file is recorded in each divided area according to a conventional technique.
FIG. 9 is an exemplary diagram illustrating a space allocation process when a new file recording request is generated in a state in which an unused space for storing a file in a storage area is insufficient, according to a preferred embodiment of the present invention.

The file system according to the present invention is characterized in that a file storage area is divided so that one-to-one correspondence can be made to image data streams that can be simultaneously stored. The file storage method based on the file system includes Only one file is recorded at the same time so that each file can be stored in successive clusters of the divided storage area. With this feature, it is possible to minimize the FAT update overhead, thereby reducing the update cost and reliability, as well as minimizing the wasted file system space.

Hereinafter, a file system of a file storage apparatus and a file storage method of the file storage apparatus according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

2 is a structural view illustrating a structure of a file system according to a preferred embodiment of the present invention.

Referring to FIG. 2, the file system 10 according to the present invention can be used in a file storage device capable of storing one or two image data streams, and includes a PBR (Partition Boot Record) area 100; A first FAT area 110; A second FAT area 120; A root directory area 130; And a file storage area 140. The file storage area includes a system storage area 142 and a predetermined number of divided storage areas 144, 145, 146, Each of the divided storage areas 144, 145, 146 and 147 of the file storage area is set to correspond one-to-one to the image data streams that can be simultaneously stored in the file storage device.

In the PBR area 100, important information of the file system such as the total size of the file system, the cluster size, and the like is stored.

The original and the copy are stored in the first FAT area 110 and the second FAT area 120, respectively, in the file allocation table (FAT) including the cluster allocation information. The root directory area 130 stores file or sub-directory information.

The file storage area 140 includes a plurality of divided storage areas 144, 145, 146, 147 divided into a predetermined number of pieces, and the divided storage areas 144, 145, 146, Are set in advance so as to correspond to each other.

The system storage area 142 of the file storage area 140 is an area for storing setting information of a device or a system to which the file storage device is applied and information about the divided storage areas is stored in the system storage area . The information on the divided storage areas recorded in the system storage area of the file storage area includes information on the number of the divided storage areas, the location information of each divided storage areas, size information of each divided storage areas, And information on the image data stream type set as it is.

In this way, the file system according to the present invention divides the file storage area into a plurality of divided storage areas to limit the number of files simultaneously recorded in any one divided storage area to one. Therefore, in the file system according to the present invention, at least one file is simultaneously recorded in each divided storage area included in the file storage area.

The file system shown in Fig. 2 is a file system of a file storage device of a vehicle black box system having a front camera and a rear camera. In an image storage device such as a vehicle black box system or a multi-channel closed circuit TV, a channel is an input path of a video data stream connected to a camera, which is an image data source. Therefore, in the case where the front camera and the rear camera are provided, it can be seen that the camera has two channels. On the other hand, the image data input from each channel is copied into one or more image data streams according to the recording type. Thus, one or more video data streams are generated simultaneously from each channel.

For example, in a vehicle black box system having a front camera and a rear camera, when providing a normal recording mode during driving and an impact sensing recording mode during driving for each camera, the number of channels of the black box system is 2, Two video data streams can be simultaneously generated from each channel. Therefore, the number of image data streams that can be simultaneously generated in the black box system is (number of channels) x (number of simultaneously generated image data streams in each channel) = 2 x 2 = 4, And is divided into four divided storage areas corresponding one-to-one to the four possible video data streams.

Therefore, the file storage area of the file system of FIG. 2, which is illustratively shown for the vehicle black box system, has four divided storage areas, and the running-recording forward camera image storage area 144 stores the running- The moving image rearview camera image storage area 145 is a divided storage area for storing the moving image data stream of the rear camera, and the event recording front image image storage area 146 is a divided storage area for storing the moving image, The event recording rear camera image storage area 147 is a divided storage area for storing the event recording image data stream of the rear camera.

In addition, the file system according to the present invention can limit the number of files that can be simultaneously recorded for each divided storage area to one at a maximum, thereby preventing fragmentation of the file system. This is because at most one file is recorded at any moment in one divided storage area, so that a continuous cluster can be allocated all the time. In addition, when the file is stored in the divided storage area, consecutive clusters are always allocated, thereby reducing the number of FAT sector writes for updating the FAT table. As a result, the overhead for updating the FAT table can be reduced .

The file system according to the present invention can not be applied to a general file storage device in which the number of simultaneously recorded files is unlimited and can be applied to a file storage device capable of limiting the number of recorded files at the same time. For example, in a vehicle black box system or a closed circuit television (CCTV) system, since the number of files simultaneously recorded in a file storage device is fixed, the storage area is divided according to the number of files, The advantages can be realized.

Hereinafter, a file storage method of a file storage apparatus according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. In particular, the file storage method according to the present invention uses the above-described file system, and can be used for a black box system for a vehicle or a file storage device for storing video and / or audio of a closed circuit TV (CCTV).

FIG. 3 is a flowchart sequentially illustrating a file storing method according to a preferred embodiment of the present invention.

Referring to FIG. 3, a file storage method according to a preferred embodiment of the present invention includes a step of formatting and initializing a file storage device to the above-described file system (step 300), a file system mounting step, A step 310 of designating a divided storage area corresponding to a file name in response to a request for recording a new file, a step of allocating a consecutive space of a predetermined size to the designated divided storage area (step 320) (Step 330), and when the recording of the file data is completed, returning the unused space among the allocated spaces (step 340). Hereinafter, each of the above-described steps will be described in detail.

First, formatting and initializing the file storage device with the above-described file system (step 300) may include a PBR (Partition Boot Record) area, a first FAT (File Allocation Table) area, FAT area, a root directory area, and a file storage area, and the file storage area is divided into one-to-one correspondence with the simultaneously recordable image data streams to create one or more divided storage areas, The information about the system is stored in the system storage area and initialized. This initialization process is performed once at the final stage of the file system formatting process, and after that, the system configuration file stored in the system storage area is read in the process of mounting the file system, thereby completing preparation for file storage.

Wherein the plurality of divided storage areas of the file storage area are set to correspond one-to-one to all the image data stream types simultaneously recordable in the file storage device, and the system storage area of the file storage area is set to correspond to one- Information is recorded. The information on the divided storage areas recorded in the system storage area of the file storage area is stored in the number of divided storage areas, the location information of each divided storage areas, the size information of each divided storage areas, It is preferable to include information on the video data stream type.

The description of the file system for each area of the file system of step 300 is the same as that for the file system described above, so repeated description will be omitted.

The file system mounting step is a step of recognizing a file system structure of a file storage device in an operating system so that a user application program can use the file storage device.

The file system preparation step is a state in which the file system mounted in the previous step waits for a request such as a read, write, or the like from the user application to come in, that is, ready state.

Next, when a new file recording request is issued together with a file name from an upper application program which drives the file storage device, a predetermined divided storage area corresponding to the file name of the file storage area is designated (step 310). Next, the unused space of the designated divided storage area is checked, and a contiguous space of a predetermined size is allocated to the identified unused space, and the FAT table is updated (step 320). Meanwhile, it is desirable that the file name provided in the file recording request includes information on the channel and information on the video data stream type.

Hereinafter, a process of allocating a space in advance according to a request for recording a new file will be described with reference to FIG. 4 is a diagram illustrating a process of allocating space to a divided storage area in advance according to a request to record a new file in a file storage method according to a preferred embodiment of the present invention.

Referring to FIG. 4, when a write request for a new file occurs together with a file name, a divided storage area for storing the file is designated, and consecutive spaces are allocated in the designated divided storage area. At this time, it is preferable that the size of the continuous space allocated in response to the file write request is set to the maximum size that the file requested to be recorded can have. In addition, in the file storing method according to the present invention, when a new file write request is generated, it is preferable that only one file is simultaneously recorded in one divided storage area.

Next, the actual file data is recorded in the allocated space (step 330). A process of recording data in a preallocated file space will be described with reference to FIG.

5 is a diagram illustrating a process of recording data in a file space allocated in advance in a file storage method according to a preferred embodiment of the present invention. Referring to FIG. 5, consecutive spaces are allocated all at once, and data is recorded in the allocated space. Since the allocated space is already allocated with the maximum size that the file can have, it is only necessary to sequentially record the data in the space. If the data recording request continues beyond the pre-allocated space, the corresponding data can not be stored and is lost. Therefore, in order to prevent such data loss, the maximum size value that the file can have beforehand has to be set appropriately. The maximum size that a file can have is determined by the resolution and encoding method of the recorded image, and is determined mainly by the manufacturer of the black box system.

Next, when the recording of the file data is completed, the unused space which is the unused space among the allocated space is returned (step 340). Hereinafter, the process of returning unused allocated space will be described with reference to FIG.

FIG. 6 is an exemplary diagram illustrating a process of returning an unused allocated space after completing file recording in the file storing method according to the preferred embodiment of the present invention. Referring to FIG. 6, upon completion of data recording in a preallocated contiguous space, clusters remaining unused in the preallocated space are returned and the FAT table is updated. Since clusters are preallocated to the maximum size that a file can have when starting to write data to a new file, it remains unused at the point when the recording of that file ends after a certain period of time (for example, 1 minute) Lt; / RTI > Therefore, it is desirable to return unused clusters so that the newly created file can be used next. As a result, the next file to be written will be able to use the returned space, so there will be no unused clusters remaining between the two adjacent files in that storage area. Therefore, the file storage method according to the present invention eliminates wasted storage space at all.

FIG. 7 is an exemplary diagram illustrating a file arrangement state after five files are recorded in one storage area in a file storage method according to a preferred embodiment of the present invention. FIG. Referring to FIG. 7, all the files are allocated consecutive spaces. As a result, not only the adjacent files and the allocated space are not mixed, but there is no wasted space between the adjacent files. . This characteristic of the file storage method according to the present invention can be very advantageous when the file system is damaged and the file data is restored.

Meanwhile, since the cluster allocation for file storage is performed for each storage area, the file storage method according to the present invention must first check the unused space for the storage area to which the file requested to be recorded belongs. At this time, if the size of the unused space is not larger than the maximum size that the file can have, it is determined that the free space is insufficient and the operation for securing the free space is entered.

However, in the conventional file storing method shown in FIG. 8, the areas for storing each file are divided into a predetermined size and one file is stored in the divided areas in advance. In this case, So that memory areas are wasted.

Hereinafter, with reference to FIG. 9, a description will be given of a process of securing unused space when there is not enough unused space for storing a file. 8 is a diagram illustrating an example of a space allocation process when a new file write request occurs in a state where there is not enough unused space for storing a file in a designated divided storage area in a file storage method according to a preferred embodiment of the present invention .

Referring to FIG. 9, in allocating a consecutive space of a predetermined size to the identified unused space, if there is no consecutive free space of the predetermined size in the unused space, It is desirable to delete an old file ('A') to secure additional unused space, and to allocate consecutive space of a predetermined size sequentially from the additional unused space obtained by deleting the unused space and file. Then, when a new file is recorded in the unused space and reaches the last cluster of the divided storage area, the data is wrapped around to the first cluster of the divided unallocated space, .

On the other hand, the file storage method according to the present invention described above can be applied to a file storage device of a car black-box system having one or two cameras, or a closed circuit television having one or two or more cameras Is applied to a file storage device of a closed circuit television ('CCTV') system, an improvement effect can be obtained in all aspects of reliability, recording performance, and efficient use of storage space.

Particularly, the improvement is fully compatible with the file system format of FAT32 or exFAT, which is basically applied to memory cards currently on the market, so that the value can be further increased.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be understood that various changes and modifications may be made without departing from the spirit and scope of the invention. It is to be understood that the present invention may be embodied in many other specific forms without departing from the spirit or essential characteristics thereof.

100: PBR (Partition Boot Record) area
110: first FAT area
120: second FAT area
130: root directory area
140: file storage area
142: System Storage Area
144, 145, 146, 147: divided storage area

Claims (11)

A method of storing a file in a file storage device capable of storing one or more video data streams,
(a) a file storage device, comprising: a PART (Partition Boot Record) area, a first FAT (File Allocation Table) area, a second FAT area, a root directory area and a file storage area, Formatting and initializing the file system into a file system characterized by comprising a storage area and a predetermined number of divided storage areas;
(b) designating a predetermined divided storage area corresponding to the file name in the file storage area when a new file recording request is made with the file name, checking the unused space of the designated divided storage area, Allocating a contiguous space of a predetermined size to the FAT table and updating the FAT table;
(c) recording actual file data in the allocated space;
(d) when recording the file data is completed, returning the unused space among the allocated spaces and updating the FAT table;
Wherein the divided storage areas of the file storage area correspond to one-to-one correspondence with image data streams that can be simultaneously stored in the file storage device, and each of the divided storage areas corresponds to one of the simultaneously- And are designated to correspond to each other,
Wherein the system storage area of the file storage area records information on the divided storage areas. The method of claim 1, wherein the file name provided in the file write request in step (b) includes information on a channel and information on a video data stream type. The method of claim 1, wherein the size of the contiguous space allocated in response to the file write request in step (b) is a maximum possible size of the file requested to be recorded. The file storage method according to claim 1, wherein, in the step (b), when a new file write request is generated, only one file is simultaneously recorded in one divided storage area How to save a file. 2. The method as claimed in claim 1, wherein, in the step (b), when allocating consecutive spaces of a predetermined size to the identified unused space, if there is no consecutive free space of the predetermined size in the unused space,
An old unused space is obtained by deleting the oldest file in the designated divided storage area,
And sequentially allocating consecutive spaces of a predetermined size from the unused space and the additional unused space from which the file is deleted. The method of claim 1, wherein the information about the divided storage areas recorded in the system storage area of the file storage area includes a number of divided storage areas, position information of each divided storage areas, Storing information on a video data stream type set to be one-to-one correspondence with storage areas. The method of claim 1, wherein the file storage method is applied to a file storage device of a car black-box system having one or more cameras,
Wherein one or more image data stream types are provided for each camera. The file storage method of claim 1, wherein the file storage method is applied to a file storage device of a closed circuit television (CCTV) system having one or two cameras . A file system of a file storage device capable of storing one or more video data streams,
A Partition Boot Record (PBR) area in which information about the file system is stored;
A first FAT area storing a file allocation table (FAT) including cluster allocation information;
The second FAT area in which a restoration FAT for the file allocation table is stored;
A root directory area in which directory entries are stored; And
A file storage area including a predetermined number of divided storage areas and a system storage area;
And,
The divided storage areas of the file storage area correspond to one-to-one correspondence with image data streams that can be simultaneously stored in the file storage device, and each of the divided storage areas is designated to correspond one-to- In addition,
Wherein the system storage area of the file storage area records information on the divided storage areas. 10. The method of claim 9,
The information on the divided storage areas recorded in the system storage area of the file storage area includes information on the number of divided storage areas, position information of each divided storage areas, size information of each divided storage areas, and one-to- Wherein the information about the video data stream type is stored in the file system. The file system according to claim 9, wherein at least one file is simultaneously recorded in each divided storage area included in the file storage area.

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