JP2000152136A - Video recording system - Google Patents

Abstract

(57) [Summary] Provided is a video recording system capable of performing a delay writing without inconsistency in a moving image file held between storage means on an application and a video server, and reducing a buffer amount required for a writing process using a file API. I do. SOLUTION: In response to a moving image write request generated by an application, a write end notification is returned, and the write request target data is sequentially temporarily stored in a write buffer of the video recording device, while the write request temporarily stored in the write buffer is returned. In a video recording system provided with a delay writing means for sequentially writing target data to a storage means on a video server side at a constant rate in a video recording apparatus side, prior to a writing operation of the delay writing means, storing of a predetermined size in the storage means A video server is provided with a destination allocating means for allocating an area for write request target data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to recording (delayed writing) video data generated by a video camera, a real-time encoder, or the like provided in a video recording apparatus on a hard disk, an optical disk, or the like on a video server connected via a network. ) Video recording system.

[0002]

2. Description of the Related Art The configuration of a conventional video recording system will be described below with reference to FIG.

[0003] An application 101 can use a file system 105 by using a file application programming interface (hereinafter, referred to as a “file API”) 102 of an operating system running on the video recording device 100. That is, the file API 102 is a file system 105 of an operating system and an application 10 running on the operating system.
This is an interface related to file input / output to / from the UNIX operating system.
n (), write (), close () ”and other system calls
"CreateFi" for Windows operating systems
The above file input / output is performed using system calls such as le (), WriteFile (), CloseHandle () ”.
And “CreateFile ()” are system calls for opening the specific file shown in parentheses,
e () ”and“ WriteFile () ”are system calls for writing data to the opened file,
"Close ()" and "CloseHandle ()" are system calls for closing an opened file. The file system 105 is connected to the network 3
The file stored in the video server 200 connected via the network driver 00 can also be accessed by interposing the network driver 106. << Writing Process >> Hereinafter, the above-described video recording apparatus 100
A process of writing video data generated at a constant rate by the above application 101 to a storage unit 203 such as a hard disk or an optical disk on the video server 200 (hereinafter referred to as “writing process”) will be described. In such a write process, it is necessary to immediately respond to a write request for video data generated at a constant rate by the application 101 (described later). Therefore, the delay write unit 104 described below and, for example, a RAM Is provided on the video recording apparatus 100 side.

First, when a file open request WO is received from the application 101 using a system call such as "open ()" or "CreateFile ()", the open request WO is accepted by the delay writing means 104. .

[0005] The delay writing means 104 notifies the file system 105 of the open request WO and secures an empty area of the write buffer 103 for the write processing.

[0006] The file system 105 notified by the delay writing means 104 stores the file of the open request target (the write processing target) in the video server 200.
If the file already exists in the storage means 203, the file is opened. If not, a new file is created in the storage means 203 and the new file is opened.

When the writing file is opened, the application 101
Issues a write request using a system call such as "write ()" or "WriteFile ()". Here, the write request is a request made for each data block of a predetermined size (the size of the data block to be written is specified in parentheses of "write ()" and "WriteFile ()"), and will be described below. In this example, the write requests WDn issued by the application 101 are referred to as “write requests WD0”, “write requests WD1”, “write requests WD2” in the order issued after the file is opened, and a final write request for the write processing target file is made. Is a “write request WDe”.

First, when the application 101 issues a write request WD0 for the data block D0, the write request WD0 is
4 is accepted.

Here, upon receiving the write request WD0, the delay writing means 104 temporarily stores the data block D0 from the application 101 in the write buffer 103, and sends a write end notification ED0 for the write request WD0 to the application 101. And issues a transfer write request WB0 for the data block D0 temporarily stored in the write buffer 103 to the file system 105.

The file system 105 that has received the transfer write request WB0 from the delay write unit 104 stores the data block D temporarily stored in the write buffer 103.
0 is written to the storage means 203 of the video server 200, and then the completion of the write processing for the data block D0 (write completion notification CD0) is notified to the delay writing means 104.
04 releases the area on the write buffer 103 that temporarily stores the data block D0. This area is
The subsequent transfer write request WBn (“0 <n”) is reused as a data block temporary storage area.

On the other hand, the application 101 which has received the write end notification ED0 for the data block D0 from the delay writing means 104 issues a write request WD1 for the data block D1 following the data block D0 to the delay writing means 104. Write request W
The delayed write unit 104 receiving D1 temporarily stores the data block D1 in the write buffer 103 and issues a write end notification ED1 for the write request WD1 to the application 101 in the same manner as in the case of the data block D0 described above. At the same time, a transfer write request WB1 for the data block D1 temporarily stored in the write buffer 103 is issued to the file system 105. Note that such a data block D1
Is performed irrespective of whether or not the writing process for the data block D0 has been completed. That is, when the delay writing unit 104 receives the transfer write request WB1 from the application 101 before receiving the write completion notification CD0 from the file system 105, the delay writing unit 104 determines whether the free space of the write buffer 103 (the area where the data block D0 is temporarily stored Data block D1 is temporarily stored in another area).

The above operation is repeated until there is no more data block to be written (until the application 101 receives the write end notification EDe for the write request WDe from the delayed write unit 104).

File close Writing is completed, for example, "close ()" or "CloseHandl".
When the application 101 issues a file close request RC using a system call such as e () ", the write request WD0 is accepted by the delayed write unit 104.

Here, the delay writing means 104 performs processing on all the data blocks Dn temporarily stored in the writing buffer 103 at the present time, that is, all the data blocks Dn which have not yet been written into the storage means 203 on the video server 200. After receiving the write completion notification CDn, the file system 105 issues a close request RC.
Notify.

The file system 105 that has received the close request RC closes the write processing target file on the video server 200.

As described above, the video recording apparatus 10 having the delay writing means 104 and the write buffer 103
According to 0, it is possible to immediately respond to a write request of video data generated at a constant rate by the application 101, and it is necessary to wait until the write to the storage unit 203 is completed to determine whether the write request has succeeded. As a result, data written in the storage means 203 can be reproduced in real time (live reproduction).

Here, the operation in the case where one application 101 operating on the video recording apparatus 100 performs a write process on one file has been described. The above-described delayed writing can also be performed when performing the writing process (for example, when performing the writing process simultaneously from the plurality of video recording devices 100 illustrated in FIG. 6). In this case, a plurality of delayed writes are performed for each of a plurality of files to be written.

[0018]

However, according to the above-mentioned conventional video recording system, even if the writing to the storage means 203 on the video server 200 fails due to, for example, a shortage of free space, the application is 101 receives the write end notification from the delay write unit 104, recognizes that the writing to the storage unit 203 has been completed normally, and continues the processing (will receive an abnormal end notification later). Therefore, inconsistency occurs in the moving image file held between the application 101 and the storage unit 203.

Further, according to the above-mentioned conventional video recording system, the write request data is always written with delay. However, in recent years, it is possible to record not only moving image data but also data other than moving images (character information, still images, and the like) in a mixed manner.
A storage unit 203 such as a VD-RAM has appeared, and when writing video data (multimedia data (see FIG. 7)) to the video server 200 having such a storage unit 203, it is not necessary to always perform delayed writing. That is, it is not necessary to delay-write even character information or still images that are not temporally continuous.
A problem arises that a large buffer amount is required for 0. In order to avoid this problem, a mechanism for delay-writing only the moving image is required. However, a unique form that does not use the file API 102, for example, TCP / IP (Transmission C
On the other hand, if only the moving picture is written in a delayed manner using the ontrol Protocol / Internet Protocol, the versatility will be lacking. That is, for example, the media player (an application in the Windows environment)
The application 101 is created based on a file API 102 called CI (Media Control Interface), and such an application 101 does not operate in the above-described unique form.

Further, in the above-described conventional write processing, the same communication protocol is used regardless of the type of data. However, data which is large in size and must be continuously written at a constant rate, such as a moving image, is stored in the network 300.
If a communication protocol for data other than a moving image is used when writing via a video, there is a problem that the processing becomes heavy, the bandwidth cannot be guaranteed, and the moving image is interrupted.

The present invention has been proposed on the basis of the above-mentioned conventional circumstances. In addition, a moving image file held between the storage means 203 on the application 101 and the video server 200 can be written with delay without any inconsistency. It is an object of the present invention to provide a video recording system capable of reducing a buffer amount required for a writing process while using the API 102.

[0022]

The present invention employs the following means to achieve the above object. That is, as shown in FIG. 1, the present invention provides a video recording apparatus 100 and a video server 2 which are interconnected via a network 300.
A video recording system consisting of 00 is assumed.
In such a video recording system, the delay writing means 104 provided in the video recording apparatus 100 returns a write end notification in response to a moving image write request generated by the application 101 and also writes the write request target data in the video recording. While the data is temporarily stored in the write buffer 103 of the device 100 sequentially, the write request target data temporarily stored in the write buffer 103 is sequentially written to the storage unit 203 of the video server 200 at a constant rate.

In the present invention, the video server 200 is provided with a pre-assignment means 205,
5 assigns a storage area of a predetermined size in the storage means 203 for write request data prior to the write operation of the delay writing means 104. This makes it possible to reliably write the data of the predetermined size into the storage unit 203.

The notifying means 206 provided on the video server 200 side notifies the video recording apparatus 100 of the size of the storage area which can be allocated for the write request target data by the pre-allocating means 205, and The means 104 determines whether or not to return a write end notification to the application 101 based on the size notified by the notification means 206. As a result, for example, a write completion notification is not returned for a write request that is considered to have failed in writing to the storage unit 203 on the video server 200 due to, for example, a lack of free space.
There is no inconsistency in the moving image file held between 1-storage means 203.

It should be noted that the predetermined size is determined by the network 3
The size determining means 204 determines the transmission delay of 00, the transfer rate of the write request target file, the format of the write request target file, the storage rate of the storage means 203, and the like.

The data type judging means 108 of the video recording device 100 judges whether or not the write request target data is moving image data based on a predetermined judgment criterion. The write request is selectively sent to the delay writing unit 104 when the data type determination unit 108 determines that the data is moving image data, or to the normal writing unit 111 when the data type determination unit 108 determines that the data is data other than a moving image. To notify.
With this configuration, since only the moving image can be written with delay, the buffer amount required for the writing process can be reduced.

Whether or not the write request data is a moving image is determined by the extension of the file name of the write request file, the identification information of the write request file, the directory where the write request file exists, the write request file. Is determined by the data type determination unit 108 based on the unit size or the like in which data is written to the data type.

[0028]

Embodiments of the present invention will be described below in detail with reference to the drawings. (First Embodiment) The write processing in the present embodiment will be described with reference to flowcharts shown in FIGS. << Write Processing >> File Open First, when there is a file open request WO from the application 101 using a system call such as "open ()" or "CreateFile ()", the open request WO is accepted by the switching means 107. .

Here, the switching means 107 starts processing (hereinafter referred to as "data type determination processing") for determining whether the file of the open request target (the write processing target) is a moving image file. To the data type determination means 108. The data type determination unit 108 receiving this instruction executes the data type determination process (described later) based on a predetermined determination criterion, and performs different operations as described below according to the determination result.

That is, if it is determined that the file is a moving image file, the data type determination unit 108
4 to determine whether or not there is an unused area in the write buffer 103, and when it is determined that there is an unused area, the switching unit 107 is instructed to use this unused area for the writing process. Upon receiving this instruction, the switching means 107 sends the open request WO to the delay writing means 1
04 (FIG. 3, steps 10 → 11 → 12).

On the other hand, if it is determined that the file is not a moving image file, the data type determining means 108
The switching means 107 instructs the switching means 107 to select the file name, and passes the open request WO to the normal writing means 111 (FIG. 3, steps 10 to 18).

The normal writing means 111 is means for directly transmitting various requests and data between the application 101 or the switching means 107 and the file system 105. Therefore, the writing process when the normal writing unit 111 is selected is a normal writing process, that is, a writing process without delay writing.

As a result, the open request W is sent to either the delayed writing unit 104 or the normal writing unit 111.
O is passed, but when the open request R _O is passed to the delay writing unit 104, the moving image communication protocol (for example, UDP or RTSP) is selected by the protocol selection unit 112 (FIG. 3, Step 1
3).

The subsequent operation is as described in the above conventional example. In other words, when the open request WO is notified to the file system 105 by the delay writing means 104 or the normal writing means 111, the file system 105 which has received the notification requests the open request WO to store the open request target file in the storage means 203 on the video server 200. If the file already exists, the file is opened. If not, a new file is created in the storage means 203 and the new file is opened (FIG. 3, steps 14 → 15).

Here, in the present embodiment, even when it is not known whether the file to be written is a moving image file, unnecessary delay writing is not performed. That is, when it is determined in step 10 in FIG. 3 that the data is unknown (for details, refer to the “data type determination process” described later).
Will be described. ), The delayed writing is first performed on the unknown file, and if there is the delayed writing unit 104 that is performing the delayed writing on other than the moving image file, the delayed writing unit 104 is switched to the normal writing unit 111. This is because writing does not cause a problem even when the unknown file is a moving image file. It should be noted that the above-described “delayed writing means 1 that performs delayed writing on a file other than a moving image file”
Also, a method of determining whether or not the data is "04" will be described in "Data type determination processing" described later. In addition, "switching the delayed writing means 104 to the normal writing means 111" means that the delayed writing is stopped. Hereinafter, it means that the above-mentioned normal write processing is performed (FIG. 3, step 10 → 16 → 17 → 12 or step 10 → 16).
→ 18).

Further, in the present embodiment, step 1 in FIG.
Also, when it is determined that there is no unused area in 1, the processing flow is the same as that in the above unknown case, so that the moving image file is preferentially delayed and written (FIG. 3, steps 11 → 16).

When the write file is opened and the application 101 issues a write request WD0 for the data block D0 using a system call such as "write ()" or "WriteFile ()", the write request WD0 is switched by the switching means. 1
07, the subsequent operation differs as follows depending on whether the delay writing unit 104 or the normal writing unit 111 is selected in the writing process.

That is, when the normal writing means 111 is selected, the switching means 107 notifies the writing request WD0 to the normal writing means 111, and the normal writing means 111 which has received the notification sends the writing request WD0 to the data block D0. The file system 105 receives the notification and stores the data block D0 in the storage unit 203 on the video server 200.
(FIG. 4, steps 20 → 21 → 22).

On the other hand, when the delay writing means 104 is selected, "temporary storage in the writing buffer 103", "writing to the storage means 203", and "pre-assignment" described below are performed. <Temporary Storage in Write Buffer 103> First, the switching unit 107 that has received the write request WD0 notifies the delay write unit 104 of the write request WD0. Here, the delayed writing unit 104
If it is determined that a write completion notification may be returned to the write block 1 (described later), the data block D0 is temporarily stored in the write buffer 103, and the write request WD0 is written.
Application end notification ED0 for application 1
01 and the write buffer 10
A transfer write request WB0 for the data block D0 temporarily stored in No. 3 is issued to the file system 105 and the destination allocation means 205 on the video server 200 (FIG. 4, steps 20 → 23 → 24 → 25).

The application 101 that has received the write end notification ED0 issues a write request WD1 for the data block D1 following the data block D0, and thereafter, the same processing as in the case of the write request WD0 is performed. Become. That is, the delayed write unit 104 that has received the write request WD1
If it is determined that a write end notification may be returned to 1,
The data block D1 is temporarily stored in the write buffer 103, and a write end notification ED1 for the write request WD1 is issued to the application 101 with this, and a transfer write request WB1 for the data block D1 temporarily stored in the write buffer 103 is generated. It is issued to the file system 105 and the destination allocation means 205 on the video server 200.

The above operation is performed by the application 1
If the delayed write means 104 does not determine that a write end notification should not be returned to the data block 01 until there is no more data block to be written (application 1
01 until the write end notification EDe for the write request WDe is received from the delayed write means 104).

It is to be noted that the above-described write processing for the data block D1 is performed irrespective of whether or not the write processing for the data block D0 has been completed, as in the above-described conventional case. <Writing to the storage means 203> In the above-mentioned "temporary storage in the write buffer 103", the delay writing means 10
4 receives the transfer write request WB0 from the write buffer 103, receives the data block D0 temporarily stored in the write buffer 103 from the delay write unit 104, and stores this data block D0 in the storage secured by “first allocation” described later. After writing in the "area for storing the data block D0" on the means 203, a write completion notice CD0 is issued to the delay writing means 104 (FIG. 4, steps 26 → 22).

The above operation is repeated until there are no more data blocks to be written (until the file system 105 does not receive the transfer write request WBn from the delay write unit 104), and each data block Dn is written to the storage unit 203. Write completion notification C
Dn is returned to the delay writing means 104.

The delayed writing means 104, having received the write completion notification CD0, releases the area on the write buffer 103 temporarily storing the data block D0, and transfers this area to the subsequent transfer write request WBn ("0 <n
The point ")" is reused as a data block temporary storage area as in the above-described conventional case.

Here, the "write buffer 10"
3 "," temporary storage in storage means 203 "
Is the same as the above-mentioned conventional writing process.
The conventional problem of inconsistency in the moving image file held between the storage means 1 and the storage means 203 cannot be solved.

Therefore, in this embodiment, the video server 200 performs “first allocation” described below, and based on the result of the “first allocation”, the delay writing unit 104 sends a write end notification to the application 101. It decides whether to return. <Pre-allocation> Upon receiving the transfer write request WB0 in the above-mentioned “temporary storage in the write buffer 103”, the destination allocation unit 205 responds to the transfer write request expected to be issued by the delayed write unit 104 following the transfer write request WB0. Provided, storage means 20 on video server 200
Allocate (secure) a storage area of a predetermined size in 3.

For example, a data block D of 64 Kbytes
Upon receiving the transfer write request WB0, the destination assignment unit 205 not only secures an area for storing the data block D0, but also allocates the transfer write requests WB1 and WB2.
An area for storing the data blocks D1, D2, and D3 of 64 Kbytes is also secured in anticipation of receiving WB3. When the transfer write request WB1 for the 64 Kbyte data block D1 is received, an area for storing the 64Kbyte data block D4 is expected in anticipation of receiving the transfer write request WB4 following the transfer write request WB3. Secure.

In the above description, the size of the data blocks D2, D3, and D4 that are the target of the transfer write requests WB2, WB3, and WB4 that have not yet been received is uniformly set to 64 Kbytes because of the target of the write request. This is because the file is a moving image file (data block D2
Since 3D4 is generated at a constant rate, the size of each data block D2D3D4 is considered to be substantially constant.

Here, the notification means 206 on the video server 200 every time the above-mentioned pre-allocation is performed, the size of the pre-allocated storage area (for example, an area for storing the data block D4 can be secured). May be notified to the delay writing unit 104 via the notification receiving unit 110 on the video recording device 100, and the delayed writing unit 104 that has received the notification notifies the application 101 based on the size. It is determined whether to return a write end notification as follows.

That is, the delayed write unit 104 returns a write end notification to the application 101 in consideration of the size of the data block temporarily stored in the write buffer 103 and the size of the storage area that can be allocated in advance. It is determined whether or not. For example, when the notification receiving unit 110 notifies that the area for storing the data block D4 has been secured while the data block D2 and the data block D3 are temporarily stored in the write buffer 103, the application 101 Upon receiving the write request WD4, the delayed write unit 104 outputs the write end notification ED4.
Is determined to be returned. On the other hand, in the above case, the delayed writing unit 104 that has received the write request WD5 from the application 101 performs the write end notification ED5.
Is determined not to be returned. By doing so, for example, a write request (in the above case, write request WD5) for which writing to the storage means 203 on the video server 200 is considered to have failed due to lack of free space or the like, is indicated by the application. 101 can be notified.

When the writing is completed and the application 101 issues a file close request RC using a system call such as “close ()” or “CloseHandle ()”, the switching means 107 stores the file in the write buffer 103. After receiving a write completion notification for all data temporarily stored, the temporary storage area of the write buffer 103 secured in the write processing is released, and the close request RC is sent to the file system 105.
(FIG. 5, steps 30 → 31).

Upon receiving the close request RC, the file system 105 closes the write processing target file on the video server 200 (FIG. 5, step 3).
2).

As described above, according to the present embodiment, the pre-allocating means 205 allocates a storage area of a predetermined size in the storage means 203 for write request target data before the write operation of the delayed writing means 104. Therefore, the data of the predetermined size can be reliably written to the storage unit 203. << Data Type Determination Process >> Hereinafter, the data type determination process in step 10 of FIG. 3 will be described.

The data type judging means 108 instructed by the switching means 107 to start the data type judging process determines that the open request target (write request target) file is a moving image file based on the following predetermined criteria. After determining whether or not there is, the switching unit 107 is notified of the determination result.

For example, when the file name of the file to be requested to write is “AAA.mpg”, the data type determination unit 108 notifies the switching unit 107 of the determination result indicating that the file is a moving image file. That is, in this case, when the extension of the file name of the write request matches the extension of a general moving image file (for example, “avi”, “mpg”, “mov”, etc.), the file of the write request target is a moving image file. Is determined. Similarly, “avi”, “mpg” is added to the identification information recorded at the head of the file (or the data of the write request) to be written.
If “mov” or the like is included, the file may be a moving image file. However, since the identification information is not information included in any type of file, a determination is made for a file that does not have such identification information. In this case, the file is determined to be an unknown file.

For example, the moving image file is stored in the “movie” directory of the E drive. If the file name (file name with a path) of the file to be written includes “E: \ movie”, The file to be requested may be a moving image file (the file name is specified in a system call such as “open ()” or “CreateFile ()”).

Further, as described below, it may be determined whether or not the write request target file is a moving image file based on the status of the write processing. For example,
When writing a moving image file, it is normal for data to be continuously transferred from the application 101 at a constant period. Whether or not the write request target file is a moving image file is determined based on whether or not the delay writing unit 104 has not received data transfer from the time application 101. The above-mentioned predetermined time (constant cycle)
Is a write request W issued by the application 101.
The time interval of Dn can be obtained by monitoring by the data type determination unit 108.

Since the unit size for writing moving image data is usually larger than the unit size for writing data other than moving image data, the unit size for writing data to the file requested to be written is a predetermined size (for example, 64K).
If the number of bytes is equal to or more than the byte, the file for which the write request is made may be determined to be a moving image file.

Further, if the write request target file is a moving image file, the offset of the write request target data usually has continuity, so that the write request target data is continuously written up to a predetermined offset value. In this case, the write request target file may be determined to be a moving image file. For example, when the predetermined offset value is A + 10, the offset of the write request target data is, for example, “A, A + 1,
If the data is continuous such as A + 2, A + 3,..., A + 10 ″, it is determined that the file for which the write request is made is a moving image file. It is determined that the file is a moving image file if it has continuity even if the amount is not by volume.

Here, an access recording means 109 for recording access information relating to the writing process is provided on the video recording apparatus 100, and the data type judging means 108 makes a judgment based on the access information recorded in the access recording means 109. If this is the case, more accurate data type determination processing can be performed. For example, if the access recording unit 109 records a unit size for writing data, the data type determination unit 108 can determine whether the writing unit size is equal to or larger than the predetermined size continuously for a predetermined number of times. it can. Further, if the access recording unit 109 records not only the write unit size but also the offset of the write request target data, it is determined whether or not data of a predetermined size or more is continuously read to a predetermined offset value. can do.

Even if the file to be requested to write is actually a moving image file, it may be more effective to determine whether or not to treat the file as a moving image file as described below. . For example, video server 2
For an open request R _O exceeding “the number of videos that can be provided by the video server 200” in a situation where a plurality of files on the file 00 are simultaneously read, the file for which the write request is made is not a video file. . The “number of videos that can be provided by the video server 200” is the video server 2
This is because it is a predetermined number determined by the performance of 00, and there is no need to delay-write a request exceeding this predetermined number (the read request file is not provided as a moving image). The number of videos that can be provided may be set in advance in the video recording device 100. However, when the video server 200 receives the request, the number of videos that can be provided and the current video Preferably, the number is notified to the video recording device 100.

Further, it may be determined whether or not to handle a file for which writing is requested as a moving image file in consideration of transmission delay and transmission quality depending on the form of the network 300. That is, the present invention can be applied to various network forms such as Ethernet (registered trademark), ATM, ISDN, xDSL, wireless using a communication satellite, and the like. It is effective to make a determination in consideration of the transmission delay and transmission quality. For example, if the video data to be written to the video server 200 connected via a device other than the Ethernet is determined to be a moving image, the video data to be written to the video server 200 connected via the Ethernet with a small transmission delay is not delayed-written. can do.

As described above, according to the present invention, whether or not a file is a moving image file is determined based on various criteria, so that efficient delayed writing can be performed.

The predetermined criterion may be a fixed value. However, the criterion is provided with judgment data storage means (not shown) for storing judgment data (judgment criterion) set by the user. It is preferable to refer to the contents set in the storage means. (Second Embodiment) In the first embodiment, the transmission delay of the network 300, the transfer rate of the write request target file (playback rate of the moving image as the write request target), the format of the write request target file,
A storage area of a predetermined size is always allocated first for the write request target data without considering various items related to the write processing such as the storage rate of the storage unit 203. That is, when one block of moving image data is written into the storage unit 203, an area for newly storing one block of moving image data is secured in the storage unit 203. Therefore, according to the first embodiment, for example, from the write buffer 103 to the storage
When the transfer delay to the
It is also conceivable that the temporary storage rate of the data block in 3 is higher than the release rate (extraction rate). As a result, the delay writing means 104 returns a write completion notice even though the storage means 203 has a sufficient free space. There may be situations where it is determined that they must not.

In order to avoid the above situation, a large area such as 1 Gbyte may be allocated first. However, according to such a method, it is necessary to always secure a huge free space in the storage means 203. A problem that must be solved. In particular, in a situation where a plurality of delayed writes (pre-assignment) are expected to be performed at the same time, the above problem becomes prominent.

Therefore, in this embodiment, the video server 200 is provided with a size determining means 204 for determining the size of a storage area to be allocated first based on various items relating to the writing processing, and the destination allocation means 205 By allocating the storage area of the size determined by the size determining means 204 for the write request target data, occurrence of the above situation is avoided.

Hereinafter, the configuration of the video recording system according to the present embodiment will be described only with respect to differences from the above-described first embodiment. Here, as an example of the size determining unit 204, a transmission delay measuring unit 204d that determines the size of a storage area to be allocated first based on the transmission delay of the network 300 will be described. <Determination of area size to be allocated first> The transmission delay measuring unit 204d determines that “the delay writing unit 104 issues a transfer writing request WBm after the delay writing unit 104 issues a transfer writing request WBm. Time required to receive write completion notification CDm
Is measured, and the size of the area to be pre-allocated is determined based on the measurement result. For example, when two data blocks are newly temporarily stored within the above-mentioned time, the number of data blocks temporarily stored in the write buffer 103 increases by one for each of the above-mentioned times, and therefore, should be allocated first. The size of the area is made larger by the area size for storing one data block every time the above time elapses (the above time corresponds to the time when the area for one data block is released in the write buffer 103). .

The method of measuring the time is not particularly limited, but the transmission delay measuring means 204d
Measures the time until the dummy data transmitted by itself is received via the network, and determines the time from “the delay writing means 104 issues the transfer write request WBm to the completion of the writing for the transfer write request WBm”. The time required for receiving the notification CDm ”may be used. Also,
Although the above description does not refer to the size of the area to be allocated first (initial allocation initial size), the initial allocation initial size is set to a size corresponding to the transmission delay of the network.

The size determining means 204 includes a transfer rate determining means 204a for determining the predetermined size based on the transfer rate of the write request target file.
Or the format determination unit 204b that determines the predetermined size based on the format (eg, MPEG2) of the write request target file, and the predetermined size based on the storage rate of the storage unit 203 (depending on the type of the storage unit 203). Storage rate measuring means 2 for determining
04c, and it is preferable to determine the above-mentioned predetermined size by combining these units according to the situation.

As described above, according to the present embodiment, it is not necessary to allocate an unnecessarily large area first.
The storage means 203 on the video server 200 can be used efficiently.

It should be noted that the writing process of the present invention corresponds to FIGS.
Is not limited to the form shown in the flowchart of FIG. For example, in the above description, the delay writing unit 104
The switching between the normal writing unit 111 and the normal writing unit 111 is performed in the step 16 in FIG. 3. However, the switching may be performed in the step 20 in FIG. 4. In this way, even if there is no unused area in step 11 in FIG. 3 and the normal writing means 111 is selected in step 18 in FIG. 3, if the unused area can be secured later, the normal writing Switching to the means 104 is possible.

The operations of the switching means 107 and the data type judging means 108 of the present invention are not limited to the above description. For example, the same effect can be obtained even if step 20 in FIG. Can be obtained.

Further, the mode of data transmission according to the present invention is not limited to the above-described mode led by the video recording apparatus 100. For example, the present invention can be applied to a mode in which data is transmitted under the initiative of the server, such as a pull-type video server 200.

[0074]

As described above, according to the present invention, since a write completion notification is not returned for a write request that may cause a write failure, the moving image held between the application and the storage means is not returned. The conventional problem of inconsistency in files can be solved.

Further, since the delay writing is performed only for the moving image, the buffer amount necessary for the writing process can be reduced.

Further, since the communication protocol for a moving image is used for the delayed writing, there is no problem that the processing becomes heavy, the bandwidth cannot be guaranteed, and the moving image is interrupted.

[Brief description of the drawings]

FIG. 1 is a schematic functional block diagram of a video recording system according to a first embodiment of the present invention.

FIG. 2 is a schematic functional block diagram of a video recording system according to a second embodiment of the present invention.

FIG. 3 is a flowchart of a file open in a write process according to the present invention.

FIG. 4 is a flowchart of writing in the writing process of the present invention.

FIG. 5 is a flowchart of file closing in a writing process according to the present invention.

FIG. 6 is a network configuration diagram.

FIG. 7 is a schematic external view of a video recording device displaying multimedia data.

FIG. 8 is a schematic functional block diagram of a conventional video recording system.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 video recording device 101 application 102 file API 103 write buffer 104 delay writing means 105 file system of video recording device 107 switching means 108 data type determining means 109 access recording means 110 notification receiving means 111 normal writing means 112 protocol selecting means 200 video server 203 storage means 204 size determining means 204a transfer rate determining means 204b format determining means 204c storage rate measuring means 204d transmission delay measuring means 205 destination allocating means 206 notifying means 300 network

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Teruto Hirota 1006 Kazuma Kadoma, Kadoma City, Osaka Prefecture F-term in Matsushita Electric Industrial Co., Ltd. 5B065 BA01 CA11 CC03 CC08 5C052 AA20 DD04 FA06 FA07 FE01 GA08 GA09 GB01 GF04

Claims (20)

[Claims] 1. A video recording apparatus comprising: a video recording device and a video server mutually connected via a network, wherein the video recording device returns a write completion notification in response to a moving image write request generated by an application and writes the write request target data to the video recording device. In the video recording system, the video recording apparatus is provided with a delay writing means for sequentially writing the write request data temporarily stored in the writing buffer to the video server side storage means at a constant rate while temporarily storing the data temporarily in the writing buffer. Prior to the write operation of the delay writing means, the video server system further comprises a destination allocating means for allocating a storage area of a predetermined size in the storage means for write request target data on the video server side. 2. A video server, comprising: a notifying unit for notifying a video recording apparatus of a size of a storage area that can be allocated for write request target data by the destination allocation unit; 2. The video recording system according to claim 1, wherein it is determined whether or not a write end notification is to be returned to the application based on the notified size. 3. The video server further comprising a size determining means for determining the predetermined size, wherein the destination allocating means allocates a storage area of the size determined by the size determining means for write request data. A video recording system according to claim 1. 4. The video recording system according to claim 3, wherein said size determining means is a transmission delay measuring means for measuring an item relating to a transmission delay of said network and determining said predetermined size based on a result of the measurement. 5. The video recording system according to claim 3, wherein said size determining means is a transfer rate determining means for determining said predetermined size based on a transfer rate of a write request target file. 6. The video recording system according to claim 3, wherein said size determining means is a format determining means for determining said predetermined size based on a format of a write request target file. 7. The video recording system according to claim 3, wherein said size determining means is a storage rate measuring means for measuring an item relating to a storage rate of said storage means and determining said predetermined size based on a result of the measurement. . 8. A video recording apparatus and a video server connected to each other via a network. The video recording apparatus returns a write completion notice in response to a video data write request generated by an application and records the write request target data in the video recording. A video recording system in which a video recording device is provided with a delay writing unit for sequentially storing the write request data temporarily stored in the writing buffer at a constant rate while sequentially storing the data in the writing buffer. A data type determination unit that determines whether the write request target data is moving image data based on a predetermined determination criterion;
Switching means for selectively notifying the delay writing means when the data type determination means determines that the data is moving image data, and selectively notifying the writing request to the normal writing means when determining that the data is data other than a moving image. And a video recording device. 9. The video recording system according to claim 8, further comprising a protocol selection unit for selecting a communication protocol for a moving image when the write request is notified to the delay writing unit. 10. The video recording system according to claim 8, wherein the data type determination means makes the determination based on an extension of a file name of a file for which writing is requested. 11. The video recording system according to claim 8, wherein said data type determination means makes said determination based on identification information of a write request target file. 12. The video recording system according to claim 8, wherein the data type determination means makes the determination based on a directory in which the write request target file exists. 13. The video recording system according to claim 8, wherein said data type determination means makes said determination based on a unit size at which data is written to a write request target file. 14. The video recording system according to claim 8, wherein the data type determination means makes the determination based on whether or not the offset of the write request target data has continuity. 15. A video recording apparatus provided with access recording means for recording access information relating to a writing process, and said data type determination means makes said determination based on access information recorded in said access recording means. The video recording system according to claim 8. 16. The video recording system according to claim 15, wherein said access recording means records the size of write request target data. 17. The video recording system according to claim 15, wherein said access recording means records an offset of write request target data. 18. The video recording system according to claim 8, wherein said data type determination means makes said determination based on a cycle of a write request. 19. The video recording system according to claim 8, wherein the data type determination means makes the determination based on the number of moving images that can be provided by the video server. 20. The video recording system according to claim 8, wherein said data type determination means makes said determination based on a form of a network.