JP2011181036A - Recording device and recording method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently access a recording medium and to prevent file destruction in spite of the occurrence of power interruption or the like during recording. <P>SOLUTION: A recording and reproducing device 100 manages, per cluster, a recording memory 111 comprising a first recording area wherein data can be updated by units of first size and a second recording area wherein data can be updated by units of second size larger than the first size, and records data of files and management information, by a file system having the management information including a FAT having arrangement information of clusters recorded therein and file entries associating files and clusters with each other, into the recording memory 111, and includes a system control part 101 which records data of files for the first recording area after recording data of files for the second recording area and then records management information for the first recording area. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a recording apparatus and a recording method for recording a file on a recording medium.

  In recent years, an apparatus for recording a video signal or the like in a file on a recording medium such as an optical disk or a semiconductor memory has become common. Data such as video recorded on a recording medium is generally managed as a file by a file system. The file system manages the size of each file, the date and time of recording, the usage status and availability of recording areas such as clusters and sectors, and records these file management information on a recording medium together with video data. In order for a recorded video to be recognized as a file and reproduced correctly, not only video data but also its file management information must be correctly recorded on the recording medium.

  Here, an example of recording video on a recording medium will be described. It is assumed that a recording medium is inserted into a recording device such as a video camera recorder and video is recorded. While the video is being recorded, the file management information changes every moment. For example, in the file management information, the size of the video file being recorded gradually increases. Furthermore, information about the recording area allocated to the video file also changes.

  If the power of the apparatus is suddenly cut off during the video recording or the recording medium is removed from the apparatus, the video is naturally cut off during the recording, and the file management information is not recorded on the recording medium. Even when such a recording medium is inserted into another recording / reproducing apparatus, the recorded video is incomplete, and the file management information related to the video is not correctly recorded on the medium. Therefore, even if a file operation such as playback or deletion of a video file on the recording medium is attempted, the file does not exist, or even if the file exists, the content data is corrupted and an error occurs, etc. The system will be destroyed.

  As a conventional example for solving such problems such as power interruption during recording, a method disclosed in Patent Document 1 is known.

  Hereinafter, Patent Document 1 will be described. First, the FAT file system employed in Patent Document 1 will be described with reference to FIGS.

  FIG. 7 is a diagram showing a recording format of a recording medium in the FAT file system. Normally, in the FAT file system defined in ISO / IEC9292, the file management information and the user data area are arranged on the logical volume of the recording medium as shown in FIG. The uppermost part of FIG. 7 represents logical sector 0. In the logical sector No. 0, a boot sector is recorded. In the boot sector, information on the entire volume and information on the location of management information such as FAT and root directory entry necessary for reading a file written in the user data area are recorded.

  FIG. 9 is a diagram showing a boot sector of the FAT16 file system. The FAT16 file system is a FAT file system defined by ISO / IEC9292. Here, information defined by ISO / IEC9293 is exemplified as information to be described in the boot sector.

  The user data area is managed in units called clusters in which one or a plurality of consecutive sectors are collected. All clusters are numbered sequentially from the top. A reserved area may be provided between the FAT describing the file arrangement information in the user data area and the boot sector. The number of sectors in the reserved area is described in the boot sector.

  In the FAT file system, it is often allowed to record a plurality of FATs, but the number of FATs and the number of sectors per FAT are described in the boot sector.

  Information about directories and files recorded in the root directory is listed after the sector immediately after one or more FATs, and the sector after the root directory entry is a user data area.

  Information about a directory is called a directory entry, and information about a file is called a file entry. In the directory entry, a directory name, a directory creation date and time, and a cluster number are recorded. In the user data area corresponding to the cluster number of the directory entry, a directory entry and a file entry belonging to the directory are recorded. In the file entry, a file name, a file creation time, a file size, and the first cluster number in which file data is stored are recorded.

  FIG. 8 is a diagram showing the relationship between files and file management information in the FAT file system, and the file recording method. A FAT entry corresponding to each cluster is prepared in the FAT. A method for recording a file 801 having a size corresponding to four clusters in the user data area will be described below.

  First, the file system creates a File1 file entry 803 in the directory entry 802 of the recording destination directory. Next, the file system finds four FAT entries that record a special bit string indicating unassigned (0x00 in the case of the FAT16 file system). If it is found that an unassigned bit string is recorded in the FAT entries (804 to 807) corresponding to the four clusters of Ath, Bth, Cth, and Dth, the file system stores the file data. The user data area is divided into four clusters and recorded. Further, in order to record the relationship between the file entry and the four clusters, the number A is recorded in the column of the first cluster number of the file entry 803. At the same time, in the FAT entry 804 corresponding to the FAT cluster A, the number of the next cluster in which the file data is recorded, that is, the number B is recorded. Similarly, the number C is recorded in the FAT entry 805 corresponding to the cluster B, and the number D is recorded in the FAT entry 806 corresponding to the cluster C. A special bit string (0xFF in the FAT16 file system) indicating the end of the file is recorded in the FAT entry 807 corresponding to the last cluster in which the file data is recorded (cluster D in this example). When reading file data from the user data area, it is possible to reach the end of the file by following this cluster connection. A file system using 12 bits per FAT entry is called a FAT12 file system, a file system using 16 bits is called a FAT16 file system, and a file system using 32 bits is called a FAT32 file system.

  Next, a method for solving the power shutdown problem of Patent Document 1 will be described with reference to FIGS.

  FIG. 10A shows the state of the file File1 before the file overwrite operation. When overwriting data corresponding to clusters 0 to 2 of File 1, first, clusters 8 to 10 for recording new file data are secured, and data are connected in the order of cluster 8, cluster 9, cluster 10 and cluster 3. In the FAT entry corresponding to the clusters 8 to 10 (FIG. 10B). Subsequently, the head cluster number is changed so that the file entry of File1 points to the cluster 8 (FIG. 10C). Finally, in order to release the clusters 0 to 2, an unassigned bit string is entered in the entries of the clusters 0 to 2 (FIG. 10 (d)).

  As described above, in the file overwrite operation, the file entry is changed, the FAT entry is secured, and the FAT entry is released. In Patent Document 1, the reservation information of the clusters 8 to 10 and the change contents of the file entry of File 1 are buffered on the main memory, while the release information of the clusters 0 to 2 is released without being written to the FAT on the main memory. Cluster numbers 0 to 2 are registered in the reservation list.

  FIG. 11 shows the release reservation list, the FAT on the main memory, and the FAT on the medium in the file overwrite operation. FIG. 11A shows a state in which an operation for releasing the above-described clusters 0 to 2 is performed. As described above, the release information of the clusters 0 to 2 is registered in the release reservation list. When recording the file management information on the medium, the allocation information of the clusters 8 to 10 is first reflected on the medium, and then the FAT entries of the clusters 0 to 2 registered in the release reservation list are released on the main memory. Then, the change contents of the file entry of File1 are recorded on the medium (FIG. 11B). When the file management information is recorded on the medium again, the released FAT entries of the clusters 0 to 2 are reflected (FIG. 11C).

  By doing so, no matter what timing the power cut-off occurs during the file overwrite operation of FIGS. 10A to 10D or the file management information recording of FIGS. 11A to 11C, File system abnormal conditions such as unassigned clusters pointed to by file entries do not occur.

  Here, a description will be given of a file system abnormal state when the power is shut down during file operation. FIG. 12A shows a state in which the file File1 is recorded in the directory 1, and the cluster A pointed to by the file entry of File1 is unallocated. This state may occur when a file entry of File 1 is recorded on the medium first when a file is newly created, and power is shut off before the FAT entry of cluster A is recorded on the medium. Or, it may occur when the FAT entry of cluster A in which an unallocated bit is inserted when deleting File1 is recorded on the medium first, and the power shutdown occurs before the File1 file entry is deleted from the medium. There is. If File 2 is newly recorded in the directory 1 in the state of FIG. 12A, the cluster A of the unallocated cluster may be used, so that the entry of File 2 also points to the cluster A as shown in FIG. Possible double reference. In the double reference state, when the data of File1 is rewritten, the data of File2 also changes, resulting in a file system abnormal state.

  In order to prevent this file system abnormal state, when newly securing a FAT entry such as file creation, the order in which the secured FAT entry is recorded on the medium and then the newly created file entry is recorded on the medium is changed. If the FAT entry such as file deletion is released and the file entry change such as change or deletion of the head cluster number is recorded on the medium first, then the released FAT entry is recorded on the medium. There is a need.

  In the file overwrite operation of Patent Document 1, securing a FAT entry, releasing a FAT entry, and changing a file entry are accompanied by one file operation. As described above, securing a FAT entry, changing a file entry, changing a FAT entry The order of liberation is preserved.

JP 2008-269520 A

  However, Patent Document 1 only mentions the recording order of the file management information, and the file may be destroyed depending on the recording order of the file data and the file management information. As shown in FIG. 13, for example, in the above-described file overwriting operation, if a power shutdown occurs in a state in which a change of a file entry is reflected on the medium before the file data is recorded on the medium, the location to be overwritten is It will be replaced with indefinite data, and the file will be destroyed.

  An object of the present invention is to provide a recording apparatus and a recording method that prevent destruction of a file or a file system even when a power interruption or removal of a recording medium occurs during recording.

  In order to achieve the above object, a recording apparatus according to the present invention can update data in a first recording area in which data can be updated in a first size unit, and in a second size unit larger than the first size. Data recorded on a recording medium including a second recording area is managed in cluster units as a file, a FAT in which cluster arrangement information in which data of the file is recorded is recorded, the file, and the file A recording apparatus for recording the file data and the management information on the recording medium by a file system having management information including information relating to a cluster in which file data is recorded; After the recording of the file data in the second recording area, the file data in the first recording area A data recording means for performing recording, after recording for the first recording area by said data recording means, and a management information recording means for recording the management information for the first recording area.

  With the above configuration, even if a power interruption occurs during recording, it is possible to prevent destruction of the file or file system.

The figure which shows the structure of the video recording / reproducing apparatus in this Embodiment The figure which shows the recording operation in this Embodiment Flow chart showing recording procedure in the present embodiment Flow chart showing recording procedure in the present embodiment The figure which shows the recording block summary recording operation in this Embodiment The figure which shows file overwrite operation in this Embodiment The figure which shows the recording format of the recording medium in a FAT file system The figure which shows the relationship between the file and file management information in a FAT file system, and a file recording method The figure which shows the boot sector of the FAT file system defined by ISO / IEC9292 The figure which shows the conventional file overwrite operation method The figure which shows the conventional FAT entry release recording process The figure which shows the abnormal state of the file system at the time of power interruption etc. during the conventional file operation The figure which shows the file destruction state in the power interruption etc. during the conventional file overwrite operation

  Hereinafter, embodiments will be described with reference to the drawings.

  FIG. 1 is a block diagram showing a configuration of a video recording / reproducing apparatus 100 according to the present embodiment. The recording / reproducing apparatus 100 includes a system control unit 101, an I / O bus 120, a removable recording memory 111, a recording memory I / F unit 110 connected to the recording memory 111, and file recording and reproduction by a user. An input unit 130 for receiving an instruction, a video input unit 132 for inputting a video signal, a video encoder 131 for encoding the video signal, a video decoder 133 for decoding the video signal, and outputting the decoded video signal Video output means 134.

  The system control unit 101 is realized by a computer including a CPU and a main storage memory, for example. The system control unit 101 includes a video file processing unit 102, a recording memory processing unit 103, a file system 104, a file system memory 105, a recording buffer memory 106, a reproduction buffer memory 107, and a metafile processing unit 108. I have. Each means included in the system control unit 101 is realized by executing various programs by the CPU. The implementation form of each memory included in the system control unit 101 is not limited. For example, a memory may be used for each application, or a single memory may be used by dividing an area for each application.

  The recording memory 111 is configured to be detachable from the video recording / reproducing apparatus 100 in the form of PCMCIA, for example. In this case, the recording memory I / F unit 110 conforms to the card bus standard. The recording memory 111 is connected to the recording memory I / F unit 110 by being inserted into a card slot as a recording medium mounting unit provided in the recording / reproducing apparatus 100, for example.

  The recording memory 111 includes two types of memory areas having different properties such as flash and MRAM. The recording memory 111 includes a first area suitable for updating small data and a second area suitable for updating large data, and file management information such as FAT and file entry, metadata, and the like in the first area. A small-size data having no real time property such as a text file (metafile) in which is recorded is arranged.

  The recording memory 111 is formatted with a file system such as FAT16. The file system 104 in the system control unit 101 writes a file to the recording memory 111 by updating the file management information and performing a data writing operation to the recording memory 111. In the present embodiment, the sector size of the recording memory 111 is 512 bytes, the cluster size is 32 KB, the recording block size of the first area is 128 KB, and the recording block size of the second area is 4 MB. The free space in the recording memory 111 is recognized by the recording memory processing means 103 via the file system 104.

  Here, a recording method when the recording / reproducing apparatus 100 records data in the recording memory 111 will be described with reference to FIGS.

  FIG. 2 is a diagram showing an example of a file recording operation in the present embodiment. The video recording operation starts when the input unit 130 receives a recording start request from the user. That is, when the input unit 130 receives an instruction to start recording, the video file processing unit 102 instructs the file system 104 to open the video file File2 for recording video. Further, when the input unit 130 receives an instruction to start recording, the metafile processing unit 108 opens the metafile File1 that records additional information (metadata) such as the compression format and frame rate of the video data. To instruct.

  The file system 104 preferentially records video data requiring real-time performance as File2. The metafile File1 and file management information, which are non-real-time data, are buffered on the file system memory 105, and are recorded at a cycle of 2 seconds when the recording buffer memory 106 is not tight. In the present embodiment, the buffered data is recorded at a cycle of 2 seconds. However, the present invention is not limited to this, and recording may be performed at any cycle. However, the file system 104 always records File2, File1, and file management information in the order of File2, File1, non-realtime data File1, and file management information as described later. Make a record.

  Here, the operation when recording non-real-time data will be described with reference to FIG.

  First, as shown in FIG. 2A, the file system 104 records the data of the video file File2, which is real-time data, in the cluster A, the cluster B, and the cluster C on the second area of the recording memory 111. Next, as shown in FIG. 2 (b), the file system 104 converts the data of the metafile File 1 that is the file data among the non-real-time data into cluster 1 and cluster 2 on the first area of the recording memory 111. To record. Finally, as shown in FIG. 2C, the file system 104 records the FAT entry and the directory entry, which are file management information, which are not yet recorded as non-real time data, in the first area of the recording memory 111. .

  Details of the recording operation of the file system 104 will be described with reference to the flowcharts of FIGS.

  FIG. 3 is a flowchart showing the recording process 1 in the present embodiment. In the recording process 1, the order of data to be recorded when the non-real time data described in FIG. 2 is recorded is shown.

  First, when it is time to record non-real time data, the file system 104 first adds all the data to be recorded to the Dirty list at the present time (S301).

  Next, in order to preferentially record the real-time data, the recording process 2 shown in FIG. 4 is performed on the file data to be recorded in the second area in the Dirty list (S302). The recording process 2 will be described later.

  Subsequently, in order to record the data of the file corresponding to the non-real time data, the file system 104 executes the recording process 2 on the file data to be recorded in the first area in the Dirty list (S303), and finally In order to record the file management information, the recording process 2 is executed on the file management information in the first area in the Dirty list (S304).

  FIG. 4 is a flowchart showing the recording process 2 in the present embodiment. The recording process 2 shows details of the process of recording in units of recording blocks.

  The file system 104 first initializes a variable cn (S401). cn is used as a variable for substituting the cluster number.

  Next, the file system 104 checks whether the cluster list is empty (S402). This is a process considering the case of taking over the cluster list set in the recording process 2 for the other input data immediately before. In the first recording process 2 of the series of recording operations shown in FIG. 3, the cluster list is empty.

  If the cluster list is empty in S402, the file system 104 selects one cluster with the smallest number from the input data (in S302 of FIG. 3, the file data recorded in the second area in the Dirty list). The number is taken out and assigned to the variable cn (S403), and the cluster corresponding to the variable cn is registered in the cluster list (S404).

  Then, the file system 104 checks whether or not clusters for the recording block size are registered in the cluster list (S405). In the case of the first area, the recording block size is 128 KB, so it is for 4 clusters. In the case of the second area, the recording block size is 4 MB, so it is 128.

  When the cluster for the recording block size is not registered in S405, the file system 104 checks whether or not there is no input data (S406).

  If there is input data in S406, the file system 104 returns to S402 and checks whether the cluster list is empty.

  If the cluster list is not empty in S402, the file system 104 checks whether or not a cluster belonging to the same recording block as the cluster registered in the cluster list exists in the input data (S407).

  If there is a cluster belonging to the same recording block in S407, the file system 104 takes out one of the clusters having the smallest number from the clusters belonging to the same recording block, and stores the number in the variable cn. Substituting (S408), the cluster corresponding to the variable cn is registered in the cluster list (S404). That is, in the recording process 2, as long as the clusters belonging to the same recording block continue, registration is continued in the cluster list and preparations for recording in units of recording blocks are made.

  When clusters for the recording block size are registered in S405, the file system 104 records all the registered clusters in the recording memory 111 (S409).

  When the recording process to the recording memory 111 is completed, the file system 104 initializes the cluster list (S410), and checks whether or not there is no input data (S406).

  If there is no cluster belonging to the same recording block in S407, the file system 104 records all registered clusters in the recording memory 111 (S409), initializes the cluster list (S410), It is confirmed whether there is no input data (S406).

  If there is no input data in S406, the file system 104 leaves the cluster list as it is, that is, if the cluster list is not empty, takes over to the next recording process 2 and ends the current recording process 2.

  In the above description, the operation regarding the recording order of the file management information is omitted. However, an abnormal state as shown in FIG. 12 may also occur in the present embodiment. It is necessary to perform processing using the released reservation list.

  Specifically, the FAT entry to be released may be added to the release reservation list instead of the Dirty list to perform the recording process 1 and be moved from the release reservation list to the Dirty list at the next non-real time data recording.

  Here, the operation of recording in units of recording blocks will be described with reference to FIG.

  FIG. 5 is a diagram illustrating an example of data recorded in the first area. As shown in the flowchart of FIG. 4, in the file recording operation in the present embodiment, data of the same recording block is recorded together. Even in the case where the file management information and the file data exist in the same recording block as in the third recording block from the top in FIG. 5, in the present embodiment, the file data recording process of the first area is performed. Next, since the file management information is recorded in the first area, the recording memory 111 can be recorded once.

  As another example of the file recording operation in the present embodiment, a file overwrite operation will be described with reference to FIG.

  FIG. 6A shows the state of the file before performing the file overwriting operation. In File1, data is recorded in clusters of cluster numbers 0 to 3 in the first area. Here, when data corresponding to the cluster numbers 0 to 2 of File 1 is overwritten, first, the file system 104 secures a cluster different from the overwriting cluster as shown in FIG. 6B. To do. Next, as shown in FIG. 6C, the file system 104 records the file data to be overwritten in the secured cluster. Then, the file system 104 records the FAT entry indicating the secured cluster (FIG. 6D), updates the directory entry (FIG. 6E), and stores the old data before being overwritten last. The FAT entries corresponding to the clusters 0 to 2 in which “1” is recorded are released (FIG. 6F).

  As described above, in the present embodiment, as shown in FIG. 6D, by recording the file data before the file management information, the data can be replaced with indefinite data even if the power is cut off. And can prevent file corruption.

  As described above, the recording / reproducing apparatus 100 can prevent the file or the file system from being destroyed even if the power is interrupted while the data is being recorded on the recording medium.

  In addition, file management information and metafile data can be buffered in the file system memory, and these data can be recorded together, eliminating the need for frequent access to recording media and high transfer rates like real-time files Can be recorded at high speed.

  Note that the file management information and metafile buffering method in this embodiment may be a method of simply holding a copy on the main memory, or an LRU (longest unused) algorithm or the like.

  In this embodiment, the data to be recorded is a video signal, but it may be data such as an audio signal.

  In the present embodiment, the semiconductor memory is described as an example of the recording medium. However, a rewritable recording medium such as an optical disk or a hard disk may be used.

  Note that each step described above in the present embodiment may be a recording program that causes a computer to execute. Furthermore, this recording program may be recorded on a computer-readable recording medium. The recording medium may be any of a semiconductor memory such as a memory card, an optical recording medium such as a CD-R and a DVD, a magneto-optical recording medium such as an MO, and a magnetic recording medium such as a flexible disk. By reading and executing the recording program from the recording program executed by the computer and the recording medium recording the recording program as described above, the computer can be driven as a control unit of the recording apparatus.

  The recording apparatus and recording method according to the present embodiment can prevent the destruction of a file or a file system even if the power is cut off or the recording medium is removed while data is being recorded on the recording medium. In addition, since the recording process can be performed efficiently, it is particularly useful for a device that records on a medium at a high rate by using a battery-driven exchange recording medium such as a video camera recorder.

DESCRIPTION OF SYMBOLS 100 Recording / reproducing apparatus 101 System control part 102 Video file processing means 103 Recording memory processing means 104 File system 105 File system memory 106 Recording buffer memory 107 Playback buffer memory 108 Metafile processing means 110 Recording memory I / F part 111 Recording memory 120 I / O bus 130 input means 131 video encoder 132 video input means 133 video decoder 134 video output means

Claims (6)

Recording is performed on a recording medium including a first recording area in which data can be updated in a first size unit and a second recording area in which data can be updated in a second size unit larger than the first size. Manage data as a file in cluster units,
A file system having management information including a FAT in which arrangement information of a cluster in which the file data is recorded and a file entry in which information for associating the file with a cluster in which the file data is recorded are recorded By
A recording device for recording the file data and the management information on the recording medium,
Data recording means for recording the file data in the first recording area after recording the file data in the second recording area;
Management information recording means for recording the management information in the first recording area after recording in the first recording area by the data recording means;
A recording apparatus comprising: The data recording means is
Buffering the file data for the first recording area in a memory;
The management information recording means
The management information for the first recording area is buffered in the memory, and the file data and the management information on the memory are recorded in the first recording area at a predetermined timing. The recording device described. The management information recording means
When recording the management information,
Reflect the FAT entry to be secured in the FAT copy in the memory;
Register the FAT entry to be released in the release reservation list,
Record the contents of the FAT copy on the memory reflecting the FAT entry to be secured in the FAT on the recording medium,
Releasing the FAT entry registered in the release reservation list from a copy of the FAT in the memory;
Recording the file entry to be changed stored in the memory in the file entry on the recording medium;
The recording apparatus according to claim 2, wherein the content of the FAT copy on the memory reflecting the FAT entry to be released is recorded in the FAT on the recording medium. For a recording medium consisting of a first recording area in which data can be updated in a first size unit and a second recording area in which data can be updated in a second size unit larger than the first size,
Manage recorded data as files in cluster units,
A file system having management information including a FAT in which arrangement information of a cluster in which the file data is recorded and a file entry in which information for associating the file with a cluster in which the file data is recorded are recorded By
A recording device for recording the file data and the management information on the recording medium,
A data recording step for recording the file data in the first recording area after recording the file data in the second recording area;
A management information recording step for recording the management information in the first recording area after recording in the first recording area in the data recording step;
Recording method. The data recording step includes
Buffering the file data for the first recording area in a memory;
The management information recording step includes
5. The management information for the first recording area is buffered in the memory, and the file data and the management information on the memory are recorded in the first recording area at a predetermined timing. The recording method described. The management information recording step includes
When recording the management information,
Reflecting the FAT entry to be secured to a copy of the FAT on the memory;
Registering the FAT entry to be released in the release reservation list;
Writing the contents of the FAT copy on the memory reflecting the FAT entry to be secured to the FAT on the recording medium;
Releasing the FAT entry registered in the release reservation list from a copy of the FAT on the memory;
Writing the file entry to be changed stored in the memory to the file entry on the recording medium;
Writing the contents of a copy of the FAT on the memory reflecting the FAT entry to be released to the FAT on the recording medium;
The recording method according to claim 5, comprising:

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