JPH10210414A - Data storage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a data storage device that stores video data and audio data as separate files in a short time, without necessitating a large storage area. SOLUTION: A CPU 21 stores video data and audio data being two files so as not to mix them, based on a name entry table 41 and a file allocation table 42 in a hard disk 40. The files are divided by changing management information of the file without moving the data themselves.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to recording a plurality of types of data output in parallel, such as video data and audio data.

[0002]

2. Description of the Related Art Conventionally, when editing video data and audio data of, for example, a movie, the video data and audio data may be converted from analog to digital and edited. At this time, for example, a movie is reproduced by an analog video device, video data and audio data are digitally converted by an encoder and stored on a hard disk. However, in order to facilitate editing work, video data and audio data are separated. Is generally stored as a file.

Conventionally, video data and audio data are separately converted by using a single hard disk drive, for example, by converting video data into digital data and storing it, and then converting audio data into digital data and storing it. I remembered. However, according to this method, it takes a long time to store the data of one movie because the movie is reproduced twice by the analog video device. On the other hand, if two hard disk drives are used for storage, video data and audio data can be stored simultaneously, but in this case, two devices for storing video data and audio data are required. This leads to an increase in cost.

Therefore, video data and audio data output in parallel from an analog video device are arranged in an appropriate order, and stored together as one file in a disk device. A method of identifying video data or audio data by moving the data on a hard disk in which the data is stored and dividing the video data and the audio data into two files has been used. According to this method, video data and audio data can be divided into two files on one hard disk. That is, only one device is required for storing the video data and the audio data. The time required to divide video data and audio data into two on a hard disk depends on hardware performance such as the access speed of a hard disk drive. This can be done in a shorter time than the time for replaying. For this reason, as described above, the video data and the audio data can be converted into digital data and stored as separate files in a time shorter than the time required to reproduce the movie twice with the analog video device.

[0005]

However, although the time required for the operation of dividing the video data and the audio data into two on the hard disk is shorter than reproducing the movie once, the video data is particularly large. When moving video data and audio data on a disk because they are data, there is a reality that reading and writing of huge amounts of data are performed, and it takes a considerable amount of time. In addition, there is a problem that a larger storage area than actual data is required to move the video data and the audio data on the hard disk.

The present invention has been made to solve the above-mentioned problems, and does not require a large storage area.
It is another object of the present invention to provide a data storage device that stores video data and audio data as separate files in a short time.

[0007]

Means for Solving the Problems and Effects of the Invention A data storage device according to a first aspect of the present invention is provided with a storage means for storing data, and stores the data in the storage means. At this time, a storage area is allocated to the data in a unit storage area, and a plurality of externally input data are stored in a data storage device capable of managing the data as a file by management information indicating a correspondence between the data and the unit storage area. By temporarily allocating the types of data individually and at least for the unit storage area, and by sequentially allocating the unit storage areas each time each type of data is stored in the temporary storage means for each unit storage area. A storage area allocating means for storing the data stored in the unit storage area in the storage means, and a storage area allocating means for the input data When the allocation of the unit storage areas is completed, the unit storage areas to which the respective types of data are allocated are searched, and the management information is changed so that the unit storage areas to which the same types of data are allocated are combined into one file. And a management information changing unit that performs

Conventionally, in a data storage device, a user manages data stored in a unit called a file, and reads and writes data in this unit. In the data storage device, in which storage area data managed as a file is stored is associated with management information. At this time, examples of the unit storage area associated with the file include, for example, a sector which is the minimum unit of access defined in terms of hardware, a cluster for collectively managing a plurality of sectors, and the like. For example, if the unit storage area is a sector,
Utilizing sector identification numbers, file “1” corresponds to sectors “1”, “2” and “4”, and file “2” corresponds to sectors “3” and “5”. It is.

The temporary storage means of the data storage device of the present invention can store a plurality of types of data input from the outside individually and at least for a unit storage area. For example, examples of video data and audio data output from an encoder will be described. At this time, the temporary storage means can individually store the two types of data, that is, the video data and the audio data input from the encoder, at least for the unit storage area. In addition,
When the temporary storage means is a single memory device, a place where video data is stored and a place where audio data is stored may be divided in advance, and each data may be stored separately. In the case of one memory device, it is conceivable to store video data in one and audio data in the other.

Each time the same type of data is stored in the temporary storage means for the unit storage area, the storage area allocating means stores the data in the storage means. As described above, since the storage area of the storage means is allocated by the unit storage area, the storage area allocation means allocates one of the unit storage areas to the data. That is, the storage area allocating means allocates the unit storage area of the storage means to the same type of data stored in the unit storage area. This prevents a plurality of types of data from being mixedly stored in one unit storage area, and the same type of data is stored in each unit storage area. For example, in the example of the video data and the audio data described above, each time the video data or the audio data is stored in the temporary storage means for the unit storage area, one unit storage area of the storage means is allocated and stored. At this time, only the video data or only the audio data is stored in the unit storage area.

When data input from the outside is completed and storage area allocation by the storage area allocation means is completed, a unit storage area to which each type of data is allocated is searched,
For example, by checking the header of the data, the unit storage area to which the same type of data is allocated is extracted. Then, the management information changing means changes the management information so that the unit storage area to which the same type of data is allocated corresponds to one file. For example, a search is made for a sector as a unit storage area, and the video data is found to be a sector "1",
If the audio data is stored in “2” and “4” and the audio data is stored in sectors “3” and “5”, one file and sectors “1”, “2” and “4” The management information is changed so as to correspond, and the management information is changed so that another file corresponds to the sectors "3" and "5". This makes it possible to manage each type of data as a separate file without moving a plurality of types of data discontinuously stored in the storage area of the storage means.

In other words, since the same type of data is stored in the unit storage area, which is a constituent unit of the file, without mixing a plurality of types of data, the correspondence between the unit storage area and the file, that is, the management information Just by changing, each type of data can be managed as a separate file.

[0013] As described above, conventionally, a plurality of types of data are stored in the storage means, and then the data itself is read and written, and the stored data is moved to another file. Therefore, it takes a long time to read and write large amounts of data such as the above-described video data and audio data, and the storage area for moving the data requires more data than the data to be stored. there were. On the other hand, in the data storage device of the present invention, only the management information is rewritten without moving the data itself stored in the storage means. As a result, it can be expected that the time required for the work of dividing the files into separate files is considerably reduced. In addition, since only the management information is rewritten, an extra storage area unlike the related art is almost unnecessary.

The above-mentioned storage means is not limited to a disk such as a hard disk, but may be a memory device such as a semiconductor memory. By the way, as described above, external data is written to the storage means when the unit storage area for each type of data is stored in the temporary storage means. There may be cases where fractions that do not appear. Therefore, in addition to the configuration described in claim 1, as described in claim 2, after the input of external data is completed, data that is less than the unit storage area of external data remains in the temporary storage means. In such a case, the shortage may be filled with stuffing bits so as to correspond to the unit storage area, and then the storage unit may be stored in the storage unit by allocating the unit storage region by the storage region allocation unit.

That is, when data smaller than the unit storage area remains in the temporary storage means, the stuffing bits, ie, meaningless packing bits, are padded to the unit storage area so as to be fractional. The unit storage area is allocated to the data of the unit storage area consisting of the data and the stuffing bits, and the fractional data is written out. As a result, the fractional data is not lost, and the video data and the audio data can be stored more accurately.

Although data input from the outside may be input in a separated state, for example, video data and audio data may be input as a time-multiplexed stream. Therefore, in addition to the configuration described in claim 1 or 2, when a plurality of types of data input from the outside are multiplexed in a time series, a plurality of types of data are temporarily stored. It is also possible to provide a configuration including a separating unit that separates each type of data so that the data is individually written into the unit.

That is, since a plurality of types of data are mixed in the multiplexed data, the separating unit determines the data type based on the information on the type of the data, and stores the plurality of types of data for each type in the temporary storage unit. It is separated so that it is stored in. For example, when a packet multiplexed stream in which packetized audio data and video data are multiplexed is input, any audio or video packet has a packet start code. Thus, by decoding the PID included in the packet start code, the type of data can be determined and separated.

Further, conventionally, as the data stored in the storage means becomes enormous data, it takes time to move the file. On the other hand, the present invention can change the file configuration without changing the physical position of the data stored in the storage means, and is particularly effective for a huge amount of data. In this sense, it seems to be particularly effective for large data such as video data and audio data such as movies.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a schematic configuration of the data storage device 1 of the present embodiment. Analog video data and audio data of a movie reproduced by the analog video device 60 are input to the compression device 50. Then, the analog video data and the analog audio data are both converted into digital data by the compression device 50, multiplexed in a time series, and output as a multiplexed stream. The data storage device 1 of this embodiment receives the multiplexed stream and stores the video data and the audio data as separate files.

The data storage device 1 includes a capture board 1
0, a CPU 21 as control means, a ROM 22 as program storage means, and a RAM 23 which operates as a work area when executing processing based on the program.
, An HD (hard disk) 40, and a disk controller 30 for accessing the HD 40.

The HD 40 stores a name entry table 41 as shown in FIG. 2A and a FAT (file allocation table) 42 as shown in FIG. 2B. F
Based on the AT 42, stored data can be managed as a file. This management method will be described later. At this time, it is assumed that a sector is used as a “unit storage area” which is a constituent unit of a storage area allocated to a file. Here, one sector has 512 bytes.

The capture board 10 includes an identification unit 11 as "separating means", and a video buffer 12 and an audio buffer 13 as "temporary storage means". It is assumed that both the video buffer 12 and the audio buffer 13 have a storage capacity of one sector, that is, 512 bytes.

Next, the operation of the data storage device 1 of the present embodiment will be described. In the data storage device 1 of the present embodiment, a method of managing data stored in the HD 40 as a file is a key point. First, a method of managing data as a file will be described in detail with reference to FIGS. I do. Here, file management that is usually performed is schematically shown.

FIG. 2A shows the name entry table 41 stored in the HD 40 as described above. The name entry table 41 shows the correspondence between the file name and the first sector constituting the file. A sector is indicated by a sector identification number (hereinafter abbreviated as “sector ID”). For example, FIG. 2A shows that the file “video data” is composed of sectors “0”. The file name and the sector ID 1
It is assumed that a 30-byte storage area is used to indicate the correspondence.

FIG. 2B shows the FAT 42 stored in the HD 40 as described above. The FAT 42 indicates a sector constituting the file. Sector is sector ID
For example, in the column of FIG. 2 (b), the sector content "1" corresponding to the sector ID "0" indicates that the file has the sector "1" following the sector "0". "
Indicates that the storage area is allocated. Similarly, the column in FIG. 2B shows that the storage area of the sector “2” is allocated to the file following the sector “1”. In the column of FIG. 2B, the sector content “end” corresponding to the sector ID “2” means that the storage area allocated to the file ends with the sector “2”. It is shown that. In addition, in the column of FIG. 2B, the sector content “no-use” for the sector ID “3” means that no data is stored in the sector “3”, that is, no file is stored in any file. This indicates that sector "3" is not allocated.

According to the name entry table 41 and the FAT 42 shown in FIGS. 2A and 2B, the file "video data" is composed of sectors "0", "1", and "2" in this order. Recognize. FIG. 3 is a flowchart showing the file operation process. This is because the name entry table 41 and the FAT4 shown in FIG.
2 shows a process for accessing a file based on the second method. This is a process executed by the CPU 21 based on a program stored in the ROM 22 when a request for a file operation is made to the data storage device 1 of the present embodiment.

First, in the first step S100,
The name entry table 41 as shown in FIG.
To access. In this process, the disk controller 3
By 0, the name entry table 41 stored in the HD 40 is accessed. Here, the file name of the file operation request is searched.

In S110, it is determined whether there is a file name to be operated. Here, when there is no file name of the operation target in the name entry table 41 (S1
10: NO), the file operation process ends. on the other hand,
If there is a file name to be operated on the name entry table 41 (S110: YES), the process proceeds to S120 with a sector having a sector ID corresponding to the file name to be operated on the name entry table 41 as a processing target sector.

In S120, the contents of the sector corresponding to the sector ID of the sector to be processed are read from the FAT 42.
Then, in S130, the sector ID of the sector to be processed is stored. Here, it is assumed that the information is stored in the RAM 23. In S140, the read sector content is the sector ID.
Is determined. Here, when the sector content is the sector ID (S140: YES), the sector ID
S120 as the sector to be processed
Is repeated. On the other hand, if the sector content is the sector ID
If not (S140: NO), the process proceeds to S150.

In S150, it is determined whether or not the sector content is "end". If the sector content is not "end" (S150: NO), the file operation process ends. On the other hand, when the sector content is “end” (S15
0: YES), to S160.

In S160, the RA in the processing of S130
Since the sector IDs constituting the file to be operated are stored in M23, the sector is accessed based on those sector IDs to perform the file operation. The above-described file operation processing will be specifically described based on the name entry table 41 of FIG. 2A and the FAT 42 of FIG. 2B.

For example, when a file operation request for the file "video data" is made to the data storage device 1 of the present embodiment, first, the name entry table 41 is accessed to search for the file name "video data". (S100). Since the name entry table 41 shown in FIG. 2A has the file name "video data" (S1
10: YES), the sector to be processed is set as the sector with the sector ID “0” from the name entry table 41 in FIG.
The FAT 42 shown in FIG.
The contents of the sector corresponding to "0" are read (S120).
Here, the sector ID “0” is stored in the RAM 23 (S
130).

The contents of the read sector are sector I
Since D is “1” (S140: YES), FIG.
The contents of the sector corresponding to the sector ID "1" are read by the FAT 42 of (b) (S120). Here, similarly, sector I
D “1” is stored in the RAM 23. Further, since the read sector content is the sector ID "2" (S140:
YES), sector ID "2" in FAT42 of FIG.
Is read out (S120). Here, the sector ID “2” is stored in the RAM 23.

Since the sector contents corresponding to the sector ID "2" in the FAT 42 of FIG. 2B is "end" (S150: YES), the sector IDs "0", "1", A file operation is performed by accessing “2”. The operation of the data storage device 1 of the present embodiment will be described on the premise of such file management.

First, the data storage processing will be described with reference to the flowchart of FIG. In this process, as shown in FIG. 1, the data storage device 1 of the present embodiment stores the video data and the audio data in the HD 40 as one file “video / audio data” based on the data output from the compression device 50. It is. This process is executed by the CPU 21 based on the program stored in the ROM 22 in FIG. In the compression device 50 shown in FIG. 1, video data and audio data output from the analog video device 60 are converted into digital data and multiplexed in time series. Then, a multiplexed stream is output from the compression device 50.

First, in the first step S200,
It is determined whether the input data is video data. This determination is made by the identification unit 11 in FIG. Here, if a positive determination is made, that is, if the data is video data, the data input in S210 is stored in the video buffer 12. On the other hand, when a negative determination is made, that is, when the data is audio data, the data input in S220 is stored in the audio buffer 13.

In S230, it is determined whether the video buffer 12 or the audio buffer 13 is full. As described above, the video buffer 12 and the audio buffer 13 have a storage capacity of 512 bytes per sector. Here, if at least one of the video buffer 12 and the audio buffer 13 is full (S230: YES), the data of the full buffer is stored in one sector of the HD 40 in S240. As a result, in the HD 40, video data and audio data are not mixed in one sector,
One sector stores only video data or only audio data. On the other hand, when neither the video buffer 12 nor the audio buffer 13 is full (S230: NO), the process proceeds to S250 without executing the process of S240.

In S250, it is determined whether data input has been completed. This is performed by determining whether the data output from the compression device 50 is exhausted by the identification unit 11. Here, if the data input has been completed (S250: YES), the process proceeds to S260. On the other hand, if the data input has not been completed (S250: NO), S
The process from 200 is repeated.

In S260, if data smaller than 512 bytes for one sector remains in the video buffer 12 and the audio buffer 13, the data is filled with meaningless stuffing data so that the video buffer 12 and the audio buffer 13 become full. Write a certain stuffing bit.

In S270, the data in the video buffer 12 and the audio buffer 13 which has become 512 bytes per sector by writing the stuffing bit is transferred to the HD4.
Store to 0. By the processing of S260 and S270 described above, even fractional data smaller than 512 bytes is stored in the HD 40 without loss.

Then, it is assumed that a name entry table 41 as shown in FIG. 5A and a FAT 42 as shown in FIG. 5B are created by executing this data storage processing. FIGS. 5A and 5B show that the file “video / audio data” is composed of sectors “0” to “5”. At this time, the same type of data is stored for each sector. That is, as shown in FIG. 5B, the video data is composed of sectors “0”, “1”,
It is stored in “3” and “5”, and the audio data is stored in sectors “2” and “4”.
The reason is that if video data or audio data of 512 bytes per sector is stored in the video buffer 12 or the audio buffer 13, respectively (S230 in FIG. 4: YES),
This is because the information is stored in the HD 40 (S240 in FIG. 4).

The CPU 21 and the disk controller 30 correspond to "storage area allocating means". S2 described above
Steps S30 and S240 correspond to the processing as storage area allocating means. Next, management information change processing in the data storage device 1 of the present embodiment will be described based on the flowcharts of FIGS. By this management information change processing, one file “video / audio data” created in the above-described data storage processing can be managed as separate files “video data” and “audio data”. This processing is performed by the CPU 21 following the data storage processing based on the program stored in the ROM 22.

First, in the first step 300 in FIG. 6, the name entry table 41 is accessed to determine whether or not the file "video / audio data" exists. By the data storage process described above, the file "video / audio data"
Is created. Here, if the file “video / audio data” does not exist (S300: NO), the management information change processing ends. When there is a file “video / audio data” (S3
00: YES), and proceeds to S310.

In S310, the name entry table 4
Then, it is determined whether or not the data stored in the first sector of the file "video / audio data" is video data. This determination is made by accessing data stored in the sector. If an affirmative determination is made here, that is, if the data stored in the first sector is video data, the file name “video / audio data” in the name entry table 41 is changed to “video data” in S320. Then, the process proceeds to S340 with the first sector as the processing target sector. On the other hand, if a negative determination is made, that is, if the data stored in the first sector is audio data, the file name “video / audio data” in the name entry table 41 is changed to “audio data” in S330. Then, the process proceeds to S340 with the first sector as the processing target sector.

In S340, the contents of the sector corresponding to the sector ID of the sector to be processed are read out based on the FAT42. In subsequent S350, it is determined whether the processing target sector is the first sector. If the processing target sector is the first sector (S350: YES), the process shifts to S370 in FIG. 7 without executing the process of S360. On the other hand, when the sector to be processed is not the first sector (S350:
NO), and it transfers to S360.

At S360, if the current sector to be processed is not the first sector constituting the file,
The data stored in the sector to be processed immediately before the current sector to be processed (hereinafter referred to as “previous sector to be processed”) and the data stored in the currently processed sector It is determined whether or not the data type is the same as the data being read. If a positive decision is made here,
That is, when the type of data stored in the previous processing target sector is the same as the type of data stored in the current processing target sector, the process proceeds to S370 in FIG. On the other hand, if a negative determination is made, that is, if the type of data stored in the previous processing target sector and the current processing target sector is different, the flow shifts to S390 in FIG.

In S370 in FIG. 7, the sector content corresponding to the sector to be processed in the FAT 42 is the sector ID.
Is determined. Here, if the sector content is not the sector ID (S370: NO), the sector content “reserved” in the FAT 42 is changed to “end”, and the management information change process ends. On the other hand, if the sector content is the sector ID (S370: YES), the process is repeated from S340 in FIG.

In S390 in FIG. 8 to which the operation proceeds when a negative determination is made in S360, it is determined whether or not a file name based on the type of data stored in the processing target sector exists in the name entry table 41. Here, when there is a file name based on the type of data stored in the sector to be processed (S390: YES), the process proceeds to S410 without executing the process of S400. On the other hand, if there is no file name based on the type of data stored in the processing target sector (S390: NO), in S400, if the stored data is audio data, the file name “audio data” If the stored data is video data, the file name “video data” is added to the name entry table 41.

In S410, it is determined whether or not the FAT 42 has sector contents "reserved". Here, when the sector content “reserved” is included in the FAT 42 (S410: YES), the sector content “reserved” is changed to the sector ID of the sector to be currently processed in S420. On the other hand, the sector contents "r"
If there is no "served" (S410: NO), S4
The process proceeds to S430 without executing the process of S20.

In S430, the FAT 42 changes the contents of the sector corresponding to the sector ID of the previous processing target sector to "re".
changed to “served”. Then, S370 in FIG.
Move to. By this management information change processing, for example, the name entry table 4 shown in FIGS.
1 and the FAT 42 are rewritten into the name entry table 41 and the FAT 42 as shown in FIGS. 9A and 9B. This will be described in detail based on a specific table shown in FIG.

First, when the data storage processing shown in FIG. 4 is completed, a file “video / audio data” is created in the name entry table 41 as shown in FIG.
This is because the data output from the compression device 50 of FIG. 1 is stored as one file in the HD 40 as described above. Therefore, an affirmative determination is made in S300 in FIG. 6, and the process proceeds to S310.

In S310, the sector having the sector ID "0" corresponding to the file "video / audio data" in the name entry table 41 shown in FIG. 5 is accessed to determine the data type. As shown in FIG. 5B, since the video data is stored in the sector “0”, S310
Is affirmatively determined, the file name “video / audio data” in the name entry table 41 is changed to “video data”. Then, assuming that the sector to be processed is sector “0”, S
Move to 340.

Next, in S340, sector I of FAT42
The sector content "1" corresponding to D "0" is read.
In S350, since the processing target sector "0" is the first sector constituting the file, an affirmative determination is made, and the process shifts to S370 in FIG. Here, the sector content corresponding to the sector ID “0” read in S340 is determined. Since the sector content is "1" and is the sector ID indicating the next sector, an affirmative determination is made in S370, and the flow shifts to S340 in FIG. At this time, the sector to be processed is sector "1".

In S 340, the contents of the sector corresponding to the sector ID “1” of the sector to be processed are read out by the FAT 42. In S350, since the processing target sector "1" is not the first sector constituting the file, a negative determination is made and the process proceeds to S360. In S360, it is determined whether or not the type of the data stored in the previous processing target sector “0” and the type of the data stored in the current processing target sector “1” are the same. This determination is made by actually accessing the sector “0” and the sector “1”. As shown in FIG. 5B, since the video data is stored in the sectors “0” and “1”, the determination is affirmative, and the process proceeds to S370.

In S370, the sector content corresponding to the sector ID of the sector to be processed is affirmatively determined because the sector ID is "2" as shown in FIG. Then, the process proceeds to S340 with the sector to be processed set as sector "2". Next, in S360, since the type of data stored in the sector “2” to be processed is different from the type of data stored in the previous sector “1” to be processed (see FIG. 5B), a negative determination is made, and S390 in FIG. Move to.

In S390, it is determined whether or not a file name based on the type of data stored in the currently processed sector "2" is in the name entry table 41. In the name entry table 41 shown in FIG. 5, "video / audio data" is changed to "video data" in S320 in FIG. However, there is no file name based on the audio data stored in sector “2” (S
390: NO). Therefore, the file name “audio data” is added in S400. Then, the sector ID “2” currently being processed is stored corresponding to the file name “audio data” in the name entry table 41. Thus, the name entry table 41 shown in FIG. 9A is created.

In S410, the sector contents "r" are stored in the FAT42.
Since there is no “served” (see FIG. 5B), a negative determination is made. Then, in S430, the contents of the sector corresponding to the sector ID “1” of the sector to be processed last time (FIG. 5)
(In (b)) is changed to “reserved”.
Then, the flow shifts to S370 in FIG.

In S370, it is determined whether or not the sector content corresponding to the sector ID "2" of the sector to be currently processed by the FAT 42 is the sector ID. The affirmative determination is made that the sector to be processed is the sector "3", and the routine goes to S340 in FIG. As shown in FIG. 5B, since the video data is stored in the sector “3” and the audio data is stored in the sector “2”, a negative determination is made in S360 and the process proceeds to S390 in FIG. Transition.

In S390, the name entry table 4
Since both the file name “video data” and the file name “audio data” have been created on FIG. And
In S410, the sector ID shown in FIG.
An affirmative determination is made because the contents of the sector corresponding to “1” have been rewritten to “reserved”.

Then, in step S420, the sector contents "rese
rved ”is the sector ID“ 3 ”of the sector currently being processed.
Rewrite to Then, in S430, the sector content “3” (in FIG. 5B) corresponding to the sector ID “2” of the previous processing target sector is rewritten to “reserved”. Then, the flow shifts to S370 in FIG.

Next, the same process is repeated with the sector to be processed set to sector "4". That is, S360 in FIG.
Then, the determination is negative, and the flow shifts to S390 in FIG. S4
10 is affirmatively determined, and FAT42 indicates that the sector ID is "2".
Is rewritten from "reserved" to sector ID "4" (S420). And
The sector content (in FIG. 5B) corresponding to the sector ID “3” is rewritten to “reserved” (S4).
30).

Next, the same process is repeated with the sector to be processed set to sector "5". That is, S360 in FIG.
Then, the determination is negative, and the flow shifts to S390 in FIG. S4
When the determination in step 10 is affirmative, the sector content corresponding to the sector ID “3” is changed from “reserved” to the sector ID “5”.
(S420). And the sector ID
The sector contents (in FIG. 5B) corresponding to “4” are rewritten to “reserved” (S430).

Then, at S370 in FIG.
Since the sector content corresponding to "5" is "end", a negative determination is made and the process shifts to S380. In S380, the sector content “reserved” in the FAT 42 is changed to “e”.
nd ". That is, the contents of the sector (in FIG. 5B) corresponding to the sector ID “4” are changed to “end”, and the management information change processing ends.

The CPU 21 and the disk controller 30 correspond to "management information changing means". In this manner, the name entry table 41 shown in FIG. 9A and the FAT 42 shown in FIG. 9B are created. At this time, the data stored in the HD 40 can be managed as two files “video data” and “audio data” by the name entry table 41 and the FAT 42 shown in FIGS. 9A and 9B. Note that the file “video data” is composed of four sectors with sector IDs “0”, “1”, “3”, and “5”, and the file “audio data” has sector IDs “2” and “4”. It consists of two sectors.

Conventionally, when one file stored as video / audio data is divided into two files, video data and audio data, the video data or audio data itself is moved on the HD 40 to be divided into two files. I was At this time, since the video data and audio data of a movie and the like are enormous data, the time required to move the data on the HD 40 was not short.
On the other hand, in the data storage device 1 of the present embodiment, video data and audio data input from the outside are stored in one sector so that video data and audio data are not mixed in one sector which is a unit storage area. Is devised so that only either the video data or the audio data is stored (see FIG. 4), and the data itself stored in the HD 40 is not moved, and the file management information is changed (see FIG. 4). 6 to 8) to divide the file.

When the management information is changed, the amount of data to be read and written becomes considerably smaller than when the data itself is moved. This will be described. Conventionally, when a file is divided by moving data itself, data stored in a sector is read and written. That is, 512-byte data is read and written.
On the other hand, as described with reference to FIG. 2, in the name entry table 41, one correspondence, that is, the correspondence between the file name and the sector ID is 30 bytes, and the FAT4
In No. 2, one correspondence relationship, that is, a correspondence relationship between a sector ID and a sector content, requires a 2-byte storage area.
That is, when rewriting a file name or adding a file name, it is sufficient to read and write 30-byte data, and when rewriting sector contents, it is sufficient to read and write 2-byte data. As a result, in the data storage device 1 according to the present embodiment in which the management information such as the name entry table 41 and the FAT 42 is rewritten, the time required for dividing the file can be significantly reduced as compared with the related art.

Further, in the case of dividing a file by moving the conventional data itself, a storage area for temporarily storing data is necessary for moving the data, and the storage area for temporarily storing data is required. Storage area is required for the HD 40. On the other hand, in the data storage device 1 of the present embodiment, since the management information is changed and the file is divided, a storage area larger than the stored video data and audio data is not required in the HD 40.

In the data storage device 1 of the present embodiment, one sector 512 is stored in the video buffer 12 and the audio buffer 13 at the end of the multiplex stream from the compression device 50.
Even when video data and audio data smaller than the bytes remain, the data less than 512 bytes is filled with stuffing bits as meaningless stuffing data (S260 in FIG. 4) and stored in the HD 40. (S270 in FIG. 4). As a result, the fractional video data and audio data are not lost.

As described above, the present invention is not limited to such embodiments at all, and can be implemented in various forms without departing from the gist of the present invention. For example, in the data storage device 1 of the above embodiment, since it is assumed that the output multiplexed stream multiplexed in time series from the compression device 50 is stored as shown in FIG.
1 was provided. However, as shown in FIG. 10, if the compression device 51 outputs the digitally converted video data and audio data separately without multiplexing,
A configuration such as the data storage device 2 including the capture board 15 without the identification unit 11 is also conceivable.

The compression device 50 of the data storage device 1 shown in FIG. 1 and the compression device 51 of the data storage device 2 shown in FIG. 10 are separate devices independent of the data storage devices 1 and 2. , The compression device 50 or the compression device 51 may be incorporated in the data storage devices 1 and 2. In this case, if the data storage devices 1 and 2 are PCs, the data storage devices 1 and 2 may be built in a PC board. Further, FIG.
10 and the compression device 51 shown in FIG. 10 may include the video buffer 12 and the audio buffer 13, and may output data when the video buffer 12 or the audio buffer 13 is full.

In the data storage device 1 of the above embodiment, the input data is audio data and video data. However, for example, a data storage device that inputs and rearranges video data arranged in chronological order is configured. It is also possible. Furthermore, in the data storage device 1 of the above embodiment, the operation of the video buffer 12 and the audio buffer 13 using the stuffing bit is performed at the end of the data output from the compression device 50. It may be used when the audio buffer 13 is not full.

Further, in the data storage device 1 of the above embodiment, the data storage device 1 shown in FIG.
The general name entry table 41 and the FAT 42 shown in FIG. Therefore, there is a need to access each sector in order to determine the type of data stored in each sector. However, new management information in the data storage device 1 may be used. For example, the FAT 42 can store not only sector contents but also data types corresponding to sector IDs. If the data type of each sector is stored in the FAT 42 when data is stored in each sector of the HD 40, the sector is not accessed at the time of file division, and the time required for file division is further reduced. It is possible to do.

Further, in the file management of the data storage device 1 of the above-described embodiment, sectors are used as unit storage areas. However, any unit may be used as a unit storage area for allocating storage areas. Such a unit storage area includes a cluster.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a schematic configuration of a data storage device according to an embodiment.

FIG. 2 is an explanatory diagram of a name entry table and a FAT.

FIG. 3 is a flowchart illustrating a file operation process.

FIG. 4 is a flowchart showing a data storage process.

FIG. 5 is an explanatory diagram of a name entry table and a FAT created by a data storage process.

FIG. 6 is a part of a flowchart of a management information change process.

FIG. 7 is a part of a flowchart of a management information change process.

FIG. 8 is a part of a flowchart of a management information change process.

FIG. 9 is an explanatory diagram of a name entry table and a FAT changed by a management information change process.

FIG. 10 is a block diagram illustrating a schematic configuration of a data storage device according to another embodiment.

[Explanation of symbols]

1, 2, ... data storage device 10, 15, ... capture board 11 ... identification unit 12 ... video buffer 13 ... audio buffer 21 ... CPU 22 ... ROM 23 ... RAM 30 ... disk controller 40 ... HD (hard disk) 41 ... name entry table 42 ... FAT 50 ... Compression device 60 ... Analog video device 70 ... Encoder

Claims (4)

[Claims] 1. A storage device for storing data, wherein when storing data in the storage device, a storage area is assigned to the data in a unit storage area, and a correspondence between the data and the unit storage area is determined. A data storage device capable of managing the data as a file based on the management information shown, a temporary storage means capable of storing a plurality of types of data input from the outside individually and at least for the unit storage area; Each time data of each type is stored in the unit storage area, the storage area allocation means for storing the data stored in the unit storage area in the storage means by sequentially allocating the unit storage areas; When the allocation of the unit storage area to the input data by the storage area allocation means is completed, each type of data is Data for retrieving the allocated unit storage area and changing the management information so that the unit storage areas to which the same type of data is allocated are collectively made into one file. Storage device. 2. After completion of input of data from the outside, if data from the outside that is less than the unit area remains in the temporary storage means, the data becomes the unit storage area. 2. The data storage according to claim 1, wherein after the shortage is filled with stuffing bits, the unit is allocated to the unit storage area by the storage area allocation unit to store the unit storage area in the storage unit. apparatus. 3. When a plurality of types of data input from the outside are multiplexed in a time series, the plurality of types of data are separated into respective types of data such that the plurality of types of data are individually written to the temporary storage unit. 3. The data storage device according to claim 1, further comprising: means. 4. The data storage device according to claim 1, wherein the plurality of types of data input from the outside are video data and audio data.