JP5489818B2 - Recording / reproducing apparatus and control method thereof - Google Patents

Description

  The present invention relates to a recording / reproducing apparatus and a control method thereof.

  2. Description of the Related Art Conventionally, a recording apparatus that records data as a file on a random access recording medium such as a memory card or a disk medium is known. In a recording apparatus, files recorded on a recording medium are managed according to a file system such as a FAT (File Allocation Table) file system.

  In the FAT file system, files recorded on a recording medium are managed using management information. Conventionally, in a recording apparatus, management information is once read from a recording medium and stored in an internal management information memory (cache memory). Then, when recording or deleting a file on the recording medium, the management information held in the memory is changed and then written to the recording medium to update the management information (see, for example, Patent Document 1).

JP 07-121311 A

  In recent years, recording devices that handle large-sized files such as moving images have appeared. As the file size increases, the size of the management information also increases proportionally. For example, when deleting a file having a large size, a large-capacity memory is required to store management information, leading to an increase in the cost of the apparatus or an increase in the circuit scale.

  The present invention aims to solve this problem. Another object of the present invention is to manage a large size file without preparing a large capacity memory.

  According to one aspect of the present invention, a file, directory information indicating the file size of the file, and a management table indicating a use state of each cluster on the recording medium are recorded on a recording medium having a plurality of clusters. Reading the directory information and the management table from the recording medium, reading the file from the recording medium based on the read directory information and the management table, and reproducing the file, and reading from the recording medium A memory for storing the directory information and the management table, and changing the directory information and the management table stored in the memory in response to an instruction to delete the file recorded on the recording medium. Management table by the recording medium control means A control unit for recording on a recording medium, wherein the control unit reads directory information of the file related to the deletion instruction from the recording medium and stores it in the memory, and then stores the file management table related to the deletion instruction. If a part of the storage table cannot be stored in the memory, the file size indicated by the directory information stored in the memory is changed based on the size of the part of the management table that can be stored in the memory. A portion that can be stored in the memory in the management table of the file related to the delete instruction, read from the recording medium, and stores the management table of the portion stored in the memory in an unused state. The recording / reproducing apparatus is characterized in that the recording / reproducing apparatus is recorded on the recording medium.

  According to the present invention, a large-sized file can be reliably deleted or managed without using a large-capacity memory.

The block diagram which shows the structure of the video camera in embodiment. The figure which shows the mode of the management information in embodiment. The flowchart which shows the file deletion process in embodiment. The flowchart which shows the shortening deletion process in embodiment. The flowchart which shows the shortening deletion process in embodiment.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited to the following embodiment, It shows only the specific example advantageous for implementation of this invention. Moreover, not all combinations of features described in the following embodiments are indispensable for solving the problems of the present invention.

  FIG. 1 is a block diagram showing a configuration of a video camera 100 which is an example of a recording / reproducing apparatus according to an embodiment of the present invention. In FIG. 1, an imaging unit 101 captures a subject and outputs a moving image signal. The buffer memory 102 is a memory for storing a moving image signal processed by each unit of the video camera 100. At the time of recording, the signal processing unit 103 performs a necessary process in addition to compressing a captured moving image signal by performing a known encoding process such as MPEG. Further, the signal processing unit 103 performs necessary processing in addition to decoding the reproduced moving image signal during reproduction. The display control unit 104 displays a moving image based on the captured moving image signal on the display unit 105 during shooting, and displays a moving image based on the reproduced moving image signal on the display unit 105 during playback. Further, the display control unit 104 displays a menu screen and various necessary information on the display unit 105 in accordance with an instruction from the CPU 107. The display unit 105 includes a liquid crystal panel and its drive circuit, and displays moving images and various types of information. The output unit 106 outputs the moving image signal photographed by the imaging unit 101 and the reproduced moving image signal to an external display device or the like.

  The CPU 107 controls each unit of the video camera 100 in accordance with an instruction received from the operation unit 108. The operation unit 108 includes various operation switches such as a power button, a mode switching button, and a menu button. The user operates the operation unit 108 to instruct shooting, reproduction, deletion, and the like of moving images. The management information memory 109 is a memory that temporarily stores management information read from the recording medium 113 as described later. The file system unit 110 manages data to be recorded on the recording medium 113. The transfer control unit 111 transmits data to be recorded to the recording medium control unit 112 in accordance with an instruction from the CPU 107 or the file system unit 110, and outputs the data read from the recording medium control unit 112 to each unit. . The recording medium control unit 112 writes and reads management information and data to and from the recording medium 113 according to instructions from the CPU 107 or the file system unit 110. In this embodiment, the recording medium control unit 112 transmits and receives commands and data according to a known interface such as ATA. The recording medium 113 is a random access recording medium such as a flash memory. In the present embodiment, the recording medium 113 is a flash memory card, and the recording medium 113 can be freely attached to and ejected from the video camera 100 by an unillustrated attachment / ejection mechanism. The bus 114 transmits and receives moving image signals and various necessary data between the respective units.

Next, recording / playback processing in the video camera 100 will be described.
First, processing during recording will be described. When the user operates the operation unit 108 to turn on the video camera 100, the CPU 107 sets the video camera 100 to a shooting mode and instructs the imaging unit 101 to start shooting a moving image. The imaging unit 101 outputs moving image signals and sequentially stores them in the buffer memory 102. Further, the CPU 107 reads out the moving image signal from the buffer memory 102 and causes the display control unit 104 to display the moving image signal on the display unit 105. In such a shooting standby state, when the user operates the operation unit 108 to instruct recording start, the CPU 107 causes the signal processing unit 103 to execute a video signal encoding process. The signal processing unit 103 reads and encodes the moving image signal from the buffer memory 102 and stores the encoded video signal in the buffer memory 102 again.

  The CPU 107 monitors the data amount of the encoded moving image signal stored in the buffer memory 102. Here, when a predetermined amount of the encoded moving image signal is stored in the buffer memory 102, the file system unit 110 and the recording medium control unit 112 are instructed to read out and record the encoded moving image signal from the buffer memory 102. . In the present embodiment, the data rate that can be recorded on the recording medium 113 is larger than the data rate of the encoded moving image signal. Therefore, after the recording medium control unit 112 starts recording the encoded moving image signal, when the data amount of the encoded moving image signal stored in the buffer memory 102 is equal to or less than the threshold value, the encoded moving image signal is written to the recording medium 113 once. To stop. Thereafter, when a predetermined amount of the encoded moving image signal is stored in the buffer memory 102 again, writing to the recording medium 113 is started. In this way, a moving image signal is intermittently recorded on the recording medium 113. When the recording unit is instructed by the operation unit 108, the CPU 107 instructs the file system unit 110 and the recording medium control unit 112 to stop recording the moving image signal and stops the encoding process by the signal processing unit 103. To do. In the present embodiment, the file system unit 110 manages moving image signals recorded between the start of recording and the stop of recording as one file. The processing of the file system unit 110 during recording will be described later.

  Next, processing during reproduction will be described. When the user operates the operation unit 108 to instruct the playback mode, the CPU 107 sets the video camera 100 to the playback mode. Then, the file system unit 110 and the recording medium control unit 112 cause the designated moving image file among the moving image files recorded on the recording medium 113 to be reproduced, and the moving image signal is stored in the buffer memory 102. Then, the signal processing unit 103 reads the reproduced moving image signal from the storage in the buffer memory 102, decodes it, and stores it again in the buffer memory 102. The display control unit 104 reads the moving image signal stored in the buffer memory 102 and displays it on the display unit 105. When an instruction to stop playback is given from the operation unit 108, the CPU 107 instructs the file system unit 110 and the recording medium control unit 112 to stop playback, and the recording medium control unit 112 stops playback of the moving image file. The processing of the file system unit 110 during reproduction will be described later.

  Next, the file system unit 110 will be described. In the present embodiment, the file system unit 110 manages files recorded on the recording medium 113 in accordance with a file system such as FAT16 or FAT32. The file system unit 110 manages data to be managed in a logical unit called a file, and the recording medium 113 has a plurality of clusters composed of a predetermined number of bits. Accordingly, the file system unit 110 manages the recording position (address) on the recording medium 113 in units of clusters.

  Further, the file system unit 110 manages files recorded on the recording medium 113 using management information. The management information includes directory information 201 and a management table 202 as shown in FIG.

  The file system unit 110 manages files in a hierarchical data structure called directories. Each directory can store further directories and files. The file system unit 110 generates a directory entry for each directory or file. Each directory entry includes a file name, directory name, file size, position information, and the like. In the position information, the first cluster number of the file and the cluster number in which the directory entry of the file or directory stored in the directory is recorded are described. The file system unit 110 can detect the configuration of the directory in the recording medium 113 and the file stored in each directory by tracing from the top directory entry. A directory located at the highest level is called a root directory, and entry information of the root directory is recorded at a specific position on the recording medium 113.

  In addition, the file system unit 110 creates a management table that indicates the usage status of all the clusters on the recording medium 113. The management table includes a plurality of management table entries. Each management table entry corresponds to one cluster, and one management table entry is represented by a predetermined number of bits (for example, 32 bits in FAT32). In the free cluster management table entry, a predetermined value indicating unused is described. The cluster management table entry in which data is recorded describes the number of the cluster in which the next data is recorded in the file. In addition, a predetermined value indicating the last cluster of the file is described in the management table entry corresponding to the cluster in which the last data constituting the file is recorded. A series of clusters on the management table representing one file in this way is called a cluster chain. In addition, the management table entry corresponding to each cluster number is recorded in the order of the clusters at a predetermined position on the recording medium 113.

  Next, processing of the file system unit 110 accompanying recording and reproduction will be described. First, processing during reproduction will be described. When there is a request for reading the designated file from the CPU 107, the file system unit 110 first instructs the recording medium control unit 112 to read data from the cluster in which the directory entry of the root directory is recorded. The recording medium control unit 112 reads the directory entry data of the root directory from the designated cluster of the recording medium 113 and sends it to the transfer control unit 111. The transfer control unit 111 stores the directory entry data of the read root directory in the management information memory 109. However, if the data of the same directory entry has already been stored in the management information memory 109, it is not necessary to read the data from the recording medium 113.

  Next, based on the directory entry information stored in the management information memory 109, the file system unit 110 reads the directory entry of the lower hierarchy directory from the recording medium 113 and stores it in the management information memory 109. As described above, the file system unit 110 repeats the directory information reading process until the directory entry of the designated file is stored in the management information memory 109.

  When the directory entry data of the designated file is stored in the management information memory 109, the file system unit 110 detects the first cluster number of the file described in the directory entry. Then, the file system unit 110 instructs the recording medium control unit 112 to read the data of the management table entry from the cluster with the detected cluster number. The recording medium control unit 112 reads the management table entry from the designated cluster and sends it to the transfer control unit 111. The transfer control unit 111 stores the read management table entry data in the management information memory 109. However, when the same management table entry is already stored in the management information memory 109, it is not necessary to read from the recording medium 113.

  Further, when the file system unit 110 detects the leading cluster of the file, the file system unit 110 converts the cluster into a logical block address (LBA) and instructs the recording medium control unit 112 to read out the actual data of the file, here, the video signal in units of sectors. Instruct. Here, the sector is a unit smaller than the cluster, and a plurality of sectors constitute one cluster. Then, the file system unit 110 designates a sector to be accessed by LBA. The recording medium control unit 112 reads data from the designated sector and sends it to the transfer control unit 111. The transfer control unit 111 stores the read data (moving image signal) in the buffer memory 102. When the reproduced moving image signal is stored in the buffer memory 102, the CPU 107 instructs the signal processing unit 103 to decode the reproduced moving image signal, and decodes the moving image signal as described above.

  As described above, when reading of the moving image signal from the first cluster is started, the file system unit 110 then uses the management table entry of the first cluster stored in the management information memory 109 to indicate the next cluster number constituting the file. Is detected. If the management table entry for the next cluster number is not stored in the management information memory 109, the file system unit 110 instructs the recording medium control unit 112 to read the management table entry for the next cluster number. The recording medium control unit 112 reads the management table entry of the designated cluster number and sends it to the transfer control unit 111. The transfer control unit 111 stores the read management table entry in the management information memory 109. At this time, a management table entry related to a cluster that has already started to read a moving image signal may be left in the management information memory 109. Alternatively, when there is no free space in the management information memory 109, the previously stored management table entry may be erased and the newly read management table entry may be stored.

  In this way, the reading of the moving image signal is continued while sequentially reading the management table entries. When the CPU 107 gives an instruction to stop playback from the operation unit 108 or when the file system unit 110 finishes reading the data of the last cluster of the file, the CPU 107 instructs the recording medium control unit 112 to stop playback. To do.

  Next, processing during recording will be described. When the operation unit 108 instructs to start recording, the CPU 107 instructs the file system unit 110 to start recording a moving image. When there is a recording instruction, the file system unit 110 specifies a directory for storing a moving image file to be newly recorded. Then, the recording medium control unit 112 is instructed to read the data of the directory entry related to this directory. The recording medium control unit 112 reads the directory entry of the designated directory from the recording medium 113 as described above. The read directory entry data is stored in the management information memory 109 by the transfer control unit 111. In addition, the file system unit 110 creates a directory entry of a moving image file to be newly recorded and stores it in the management information memory 109.

  Next, the file system unit 110 designates one of the free clusters in the management table as the first cluster of the file. Then, it instructs the recording medium control unit 112 to read the management table entry of the designated cluster. The recording medium control unit 112 reads out the management table entry of the designated free cluster and sends it to the transfer control unit 111. The transfer control unit 111 stores the read management table entry in the management information memory 109. The file system unit 110 describes the cluster number of the first cluster of the file in the directory entry stored in the management information memory 109.

  When the CPU 107 requests to write a moving image signal encoded as described above, the file system unit 110 causes the transfer control unit 111 to transfer the moving image signal from the buffer memory 102 to the recording medium 113. Then, the file system unit 110 instructs the recording medium control unit 112 to write a moving image signal to an empty cluster of the recording medium 113.

  When the writing of the moving image signal to one cluster is completed, the file system unit 110 detects the next free cluster and stores the management table entry in the management information memory 109. Similarly, a moving image signal is recorded for an empty cluster. Further, the file system unit 110 describes the next cluster number in the management table entry of each cluster stored in the management information memory 109 in accordance with the writing of the moving image signal.

  In this manner, moving image signals are sequentially written to the recording medium 113. When there is an instruction to update management information from the CPU 107 during recording of a moving image signal, the file system unit 110 records the directory information and the management table stored in the management information memory 109 at that time on the recording medium 113. Instructs the recording medium control unit 112. The transfer control unit 111 reads the directory information and the management table stored in the management information memory 109 in accordance with the update instruction from the file system unit 110, and transmits it to the recording medium control unit 112. The recording medium control unit 112 records the directory information and the management table in the determined sectors of the recording medium 113, respectively, thereby updating the management information regarding the moving image file recorded up to that point. In the present embodiment, the CPU 107 instructs the management information to be updated at regular time intervals after starting the recording of the moving image signal.

  As described above, when the management information of the recording medium 113 is updated, the management table newly read from the recording medium 113 is set with the storage area of the management table stored in the management information memory 109 up to that time as a free area. Used to memorize. The directory information is held in the management information memory 109 until writing of one moving image file is completed.

  When a recording stop instruction is issued from the operation unit 108, the CPU 107 instructs the file system unit 110 and the recording medium control unit 112 to stop recording the moving image signal. The file system unit 110 stops the transmission of the moving image signal from the buffer memory 102 to the recording medium control unit 112 in response to the recording stop instruction. Then, the recording medium control unit 112 stops recording the moving image signal on the recording medium 113.

  When the recording of the moving image signal is stopped, the file system unit 110 describes a value indicating the end of the file in the management table entry of the last cluster of the moving image file stored in the management information memory 109. Further, the file system unit 110 detects the size of the recorded moving image file, and describes the file size for the directory entry stored in the management information memory 109. Then, the file system unit 110 instructs the recording medium control unit 112 to record the directory information and the management table stored in the management information memory 109 on the recording medium 113. The transfer control unit 111 reads the directory information and the management table stored in the management information memory 109 in accordance with the update instruction from the file system unit 110, and transmits it to the recording medium control unit 112. The recording medium control unit 112 updates the management information related to the moving image file recorded by the current recording instruction by recording the directory information and the management table in the determined sectors of the recording medium 113, respectively.

  Further, the file system unit 110 monitors the size of the moving image file being recorded. When the size of the moving image file being recorded approaches the upper limit size defined by the file system, the file system unit 110 temporarily closes the file being recorded, creates a new file, and continues recording the moving image signal. . When the file is closed, the directory information and management table stored in the management information memory 109 are changed and written to the recording medium 113 in the same manner as when recording is stopped. As for the creation of a new file, a new directory entry is created and stored in the management information memory 109 in the same manner as when recording is started.

  Thus, the maximum size of a moving image file that can be recorded by the video camera 100 of this embodiment is the upper limit size defined by the file system. As described above, as the file size increases, the size of the management table related to this file also increases. However, since the management table on the recording medium 113 is updated at regular time intervals during file recording, the storage area in the management information memory 109 can be used as an empty area after the update. Further, at the time of reproduction, only the management table entry related to the cluster to be read out needs to be stored in the management information memory 109. In this way, it is not necessary to store all the management tables of the upper limit size moving image files in the management information memory 109 for recording and reproducing moving images. For this reason, in the present embodiment, the storage capacity of the management information memory 109 is set to a size required for recording / playback processing that is smaller than the size of the management table of the upper limit size moving image file.

  Next, the file deletion operation will be described. FIG. 3 is a flowchart showing the file deletion process. Note that the file deletion process described below is executed by the CPU 107 controlling each unit. When the user operates the operation unit 108 to instruct to display a list of moving image files recorded on the recording medium 113, the CPU 107 instructs the file system unit 110 to acquire file list information. The file system unit 110 instructs the recording medium control unit 112 to read the directory entries of all the files recorded on the recording medium 113. When the directory entry of each file read by the recording medium control unit 112 is stored in the management information memory 109, the CPU 107 causes the display control unit 104 to display a list screen indicating the file name information of each file. To display. The user operates the operation unit 108 to designate a file to be deleted from the displayed list screen and instruct to delete the file.

  The flow of FIG. 3 starts in response to this file deletion instruction. First, the file system unit 110 instructs the recording medium control unit 112 to read out directory information related to a file related to the deletion instruction (deletion target file) (S301). Here, the directory entry of the deletion target file and the directory entries related to the directories of all the layers in which the deletion target file is stored are read out. However, if a directory entry related to this file has already been stored in the management information memory 109, it is not necessary to read it out.

  As described above, when the user designates a file to be deleted from the file list screen, the directory entry of the designated file is already stored in the management information memory 109. Erase from the memory 109. Then, the directory entries relating to the directories of all the hierarchies storing the deletion target file are newly read out.

  Next, the file system unit 110 detects the file size of the deletion target file based on the directory entry of the deletion target file stored in the management information memory 109. Then, based on the file size of the file to be deleted, the file system unit 110 detects the size of the management table of this file and notifies the CPU 107 (S302). Specifically, the file system unit 110 obtains the number of management table entries related to this file based on the file size and the size per cluster. Then, the size of the management table is calculated by multiplying the number of management table entries by the number of bits of one management table entry.

  As described above, the directory information of the deletion target file is currently stored in the management information memory 109. In this state, it is determined whether all the management tables related to the deletion target file can be stored in the management information memory 109. For this purpose, the CPU 107 compares the size of the directory information related to the file to be deleted, the size of the management table, and the capacity of the management information memory 109. Then, it is determined whether or not the total size is less than or equal to the capacity of the management information memory 109 (S303).

  If the total size is equal to or smaller than the capacity of the management information memory 109 as a result of determination, the file system unit 110 detects the first cluster number of the file described in the directory entry of the file to be deleted stored in the management information memory 109. To do. Then, the recording medium control unit 112 is instructed to read all management table entries related to the deletion target file from the first cluster, and all the read management table entries are stored in the management information memory 109 (S304).

  Next, the file system unit 110 deletes the directory entry of the file to be deleted stored in the management information memory 109. Also, the contents of the directory entry related to the directory storing the file to be deleted are changed. Further, all management table entries related to the deletion target file are changed to a predetermined value indicating an empty cluster (S305). When the change of the directory information and management table stored in the management information memory 109 is completed, the file system unit 110 controls the recording of the directory information and management table stored in the management information memory 109. Specifically, the file system unit 110 instructs the recording medium control unit 112 to record the directory information and the management table stored in the management information memory 109 in a specified cluster of the recording medium 113 ( S306). The transfer control unit 111 reads directory information and a management table from the management information memory 109 and sends them to the recording medium control unit 112. The recording medium control unit 112 records the directory information and the management table in the specified clusters in the recording medium 113, respectively.

  On the other hand, if it is determined in S303 that the total size of the directory information and the management table is larger than the capacity of the management information memory 109, a file shortening / deleting process is executed (S307).

  FIG. 4 is a flowchart showing the file shortening / deleting process of S307. First, the file system unit 110 determines whether deletion target file directory information is stored in the management information memory 109 (S401). When it is determined that the directory information of the deletion target file is not stored in the management information memory 109, the file system unit 110 reads the directory information of the deletion target file. The read directory information is stored in the management information memory 109 (S402).

  Next, the file system unit 110 detects the file head cluster number described in the directory entry of the file to be deleted stored in the management information memory 109, and stores it in the management information memory 109 (S403). Then, the file system unit 110 changes the file size in the directory entry of the file to be deleted stored in the management information memory 109 based on the data amount of the management table that can be stored in the management information memory 109 (S404). Here, the file system unit 110 obtains a capacity capable of storing the management table of the file to be deleted in the management information memory 109. The storable capacity is a capacity excluding the capacity necessary for storing the information of the start cluster number stored in S403 out of the capacity of the management information memory 109. Then, the number of management table entries that can be stored in the management information memory 109 is calculated. A value obtained by multiplying the calculated number of management table entries by the data amount per cluster is subtracted from the file size of the file to be deleted. Then, the file size described in the directory entry is changed to a value obtained as a result of the subtraction.

  When the directory information is changed in this way, the file system unit 110 instructs the recording medium control unit 112 to record the changed directory information on the recording medium 113. The recording medium control unit 112 records the directory information transmitted from the management information memory 109 by the transfer control unit 111 in a specified sector of the recording medium 113 (S405). After the directory information is recorded, the area storing the directory information in the management information memory 109 is made an empty area, that is, an unused state.

  Next, the file system unit 110 determines whether or not the management table of the file to be deleted is stored in the management information memory 109 (S406). When it is determined that the management table is not stored in the management information memory 109, the management information memory 109 reads out the size that can be stored in the management information memory 109 from the management table entry at the end of the file in the management table of the file to be deleted. Remember me. Specifically, this processing is performed as follows, for example. The file system unit 110 causes the recording medium control unit 112 to read the management table of the files to be deleted in the order of the cluster chain from the first management table entry (S407). The read management table entries are sequentially stored in the management information memory 109 by the transfer control unit 111. When the management table entry is stored in the management information memory 109, the file system unit 110 determines whether or not the management table entry stored in the management information memory 109 includes a value indicating the end of the cluster chain (S408). . If the management table entry on the management information memory 109 is not a value indicating the end of the file, the process returns to S407 to continue reading the management table entry. In this way, the process is repeated until the management table entry at the end of the file is stored in the management information memory 109. Here, when the management information memory 109 becomes empty when it is read from the first management table entry and stored in the management information memory 109, it is overwritten in order from the first management table entry. Therefore, at the stage where the management table entry of the last cluster is stored in the management information memory 109, the management table entry having a capacity corresponding to the management information memory 109 is stored from the end of the file.

  When the management table entry at the end of the file is stored in the management information memory 109, the file system unit 110 changes the value of each management table entry of the file to be shortened stored in the management information memory 109 to a value indicating a free area. (S409). In this way, the part of the management table stored in the management information memory 109 is changed to an unused state. However, among the management table entries stored in the management information memory 109, the management table entry at the head of the cluster chain is changed to a value indicating the end of the file.

  As described above, when each management table entry stored in the management information memory 109 is changed, the file system unit 110 instructs the transfer control unit 111 to transfer the changed management table to the recording medium control unit 112. Then, the file system unit 110 instructs the recording medium control unit 112 to record the changed management table on the recording medium 113 (S410). After executing the file shortening / deleting process in this way, the processes of S301 to S303 in FIG. 3 are repeated again.

  The state of management information during the file shortening / deleting process is shown in FIGS. FIG. 2B shows the directory information 203 and management table 204 of the file to be deleted. Reference numeral 205 denotes the data amount of the directory information 203 of the file to be deleted, and 206 denotes the size (number of entries) of the management table 204 that can be stored in the management information memory 109 calculated in S302.

  As shown in FIG. 2B, a part of the management table of the file to be deleted cannot be stored in the management information memory 109 storing the directory information. Therefore, the directory information is changed so that the file size corresponds to the management table entry excluding the number of entries corresponding to the data amount 206 from the number of entries in the management table 204.

  Further, the management table at the end of the file is stored in the management information memory 109 as shown in FIG. In FIG. 2C, reference numeral 207 denotes the data amount of the management table stored in the management information memory 109 by the processing of S407 and S408. In step S409, each entry in the data amount management table indicated by 207 is changed to a free cluster. Note that the data amount 207 is larger than the data amount 206 because the directory information storage area is used for storing the management table after the directory information is written to the recording medium 113 in S405. . Reference numeral 208 denotes a management table entry that newly becomes the end of the file after the file abbreviated deletion process. The management table entry 208 is changed to a value indicating the end of the file.

  Thus, in this embodiment, when deleting a file, if a part of the management table of the file to be deleted cannot be stored in the management information memory, the file size indicated by the directory information is changed. Then, the management table entry that is equal to or larger than the changed file size is stored in the memory and changed to a free area. By repeating this process, the file can be deleted normally even when the capacity of the management information memory is reduced. Even when the power of the video camera is cut off during the file deletion process, it is possible to prevent the data recorded on the recording medium 113 from being inconsistent with the management information. For this reason, it is possible to prevent the file recorded on the recording medium 113 from being read out.

  In this embodiment, in S303, the total size of the directory information related to the deletion target file and the size of the management table is compared with the capacity of the management information memory 109. However, it is also possible to use the management information memory 109 for other purposes. In this case, the capacity that can be used for storing the directory information and the management table in the area of the management information memory 109 is compared as the memory capacity. Is also possible.

  Further, the example shown in FIG. 2 shows a case where the total size of the directory information and the management table is less than the capacity of the management information memory 109 by one file shortening / deleting process. However, there may be a case where the total size of the directory information and the management table is not less than the capacity of the management information memory 109 in one file shortening / deleting process. In that case, the process of FIG. 4 is repeatedly executed.

  Next, a second embodiment will be described. The configuration and basic operation of the video camera 100 in the present embodiment are the same as those in the first embodiment. In the second embodiment, the file shortening / deleting process in S307 is different. The file shortening / deleting process according to this embodiment will be described below.

  FIG. 5 is a flowchart showing the file shortening / deleting process of S307. First, the file system unit 110 determines whether deletion target file directory information is stored in the management information memory 109 (S501). When it is determined that the directory information of the deletion target file is not stored in the management information memory 109, the file system unit 110 reads the directory information of the deletion target file. The read directory information is stored in the management information memory 109 (S502).

  Next, the file system unit 110 detects the file head cluster number described in the directory entry of the file to be deleted stored in the management information memory 109 and stores it in the management information memory 109 (S503). Then, the file system unit 110 changes the file size indicated by the directory entry of the file to be deleted stored in the management information memory 109 based on the data amount of the management table that can be stored in the management information memory 109 (S504). Here, the file system unit 110 can perform the same processing as in S404 described above. That is, the number of management table entries that can be stored in the management information memory 109 is calculated, and a value obtained by multiplying the calculated number of management table entries by the data amount per cluster is subtracted from the file size of the file to be deleted. . Then, the file size described in the directory entry is changed to a value obtained as a result of the subtraction.

  Next, the file system unit 110 detects a cluster number after the number of management table entries that can be stored in the management information memory 109 from the management table of the file to be deleted in order from the first cluster to the cluster chain. Then, the head cluster number described in the directory entry of the file to be deleted stored in the management information memory 109 is changed to the cluster number detected here (S505). Further, the changed leading cluster number is stored in the management information memory 109.

  When the directory information is changed in this way, the file system unit 110 instructs the recording medium control unit 112 to record the changed directory information on the recording medium 113. The recording medium control unit 112 records the directory information transmitted from the management information memory 109 by the transfer control unit 111 in a specified sector of the recording medium 113 (S506). After the directory information is recorded, an area where the directory information is stored in the management information memory 109 is set as an empty area.

  Next, the file system unit 110 instructs the recording medium control unit 112 to read out the management table in the order of the cluster chain from the first cluster of the file to be deleted before the change saved in S503 (S507). The read management table is sequentially stored in the management information memory 109 by the transfer control unit 111. When the management table entry is stored in the management information memory 109, the file system unit 110 determines whether or not the management table entry stored in the management information memory 109 includes the changed first cluster number saved in S505. (S508). If the management table entry in the management information memory 109 does not include the changed first cluster number, the process returns to S507 and the management table entry is continuously read.

  When the management table entry including the changed first cluster number is stored in the management information memory 109, the file system unit 110 sets the value of each management table entry of the file to be shortened stored in the management information memory 109 to an empty area. Change (S509). As described above, when each management table entry stored in the management information memory 109 is changed, the file system unit 110 instructs the transfer control unit 111 to transfer the changed management table to the recording medium control unit 112. Then, the file system unit 110 instructs the recording medium control unit 112 to record the changed management table on the recording medium 113 (S510). After executing the file shortening / deleting process in this way, the processes of S301 to S303 in FIG. 3 are repeated again.

  FIG. 2D shows the state of management information during the file shortening / deleting process in the present embodiment. As shown in FIG. 2B, a part of the management table of the file to be deleted cannot be stored in the management information memory 109 storing the directory information. Therefore, the directory information is changed so that the file size corresponds to the management table entry excluding the number of entries corresponding to the data amount 206 from the number of entries in the management table 204.

  Furthermore, as shown in FIG. 2D, the management information is stored in the management information memory 109 in the order of the cluster chain from the top of the management table. In FIG. 2D, 209 is the data amount of the management table stored in the management information memory 109 by the processing of S507 and S508. In step S509, each entry in the data amount management table indicated by 209 is changed to a free cluster. Reference numeral 210 denotes a management table entry that newly becomes the first cluster of the file after the file shortening / deleting process. Therefore, in S505, the cluster number of the management table entry 210 is detected and the head cluster number is changed.

  Thus, in this embodiment, when deleting a file, if a part of the management table of the file to be deleted cannot be stored in the management information memory, the file size indicated by the directory information is changed. Then, the management table entry that is equal to or larger than the changed file size is stored in the memory and changed to a free area. By repeating this process, the file can be deleted normally even when the capacity of the management information memory is reduced. Even when the power of the video camera is cut off during the file deletion process, it is possible to prevent the data recorded on the recording medium 113 from being inconsistent with the management information. For this reason, it is possible to prevent the file recorded on the recording medium 113 from being read out. Furthermore, in the second embodiment, by shortening the file from the front, it is sufficient to trace the cluster chain once to the end of the file while deleting the read cluster chain, so that the execution speed can be increased.

(Other embodiments)
The present invention can also be realized by executing the following processing. That is, software (program) that realizes the functions of the above-described embodiments is supplied to a system or apparatus via a network or various storage media, and a computer (or CPU, MPU, or the like) of the system or apparatus reads the program. It is a process to be executed. In this case, the program and the storage medium storing the program constitute the present invention.

Claims (5)

A file, directory information indicating a file size of the file, and a management table indicating a use state of each cluster in the recording medium are recorded on a recording medium having a plurality of clusters, and the directory information and Recording medium control means for reading the management table, reading the file from the recording medium based on the read directory information and the management table, and reproducing the file;
A memory for storing the directory information and the management table read from the recording medium;
In response to an instruction to delete the file recorded on the recording medium, the directory information and management table stored in the memory are changed, and the changed directory information and management table are recorded on the recording medium by the recording medium control means. And a control unit
The control unit cannot store a part of the management table of the file related to the deletion instruction in the memory after the directory information of the file related to the deletion instruction is read from the recording medium and stored in the memory. In this case, the file size indicated by the directory information stored in the memory is changed based on the size of the portion of the management table that can be stored in the memory, and recorded on the recording medium. A portion of the management table that can be stored in the memory is read from the recording medium and stored in the memory, and the management table of the portion stored in the memory is changed to an unused state and recorded on the recording medium. A characteristic recording / reproducing apparatus. The control unit cannot store a part of the management table of the file related to the deletion instruction in the memory after the directory information of the file related to the deletion instruction is read from the recording medium and stored in the memory. If
The file size indicated by the directory information stored in the memory based on the size that can be stored in the memory in the management table is changed and recorded on the recording medium,
From the recording medium, out of the management table of the file related to the deletion instruction, the size of data stored in the memory is read from the management table entry at the end of the file, and stored in the memory.
Change the management table entry at the beginning of the management table stored in the memory to a value indicating the end of the file, change the other management table entries to values indicating unused, and record the changed management table as the record The recording / reproducing apparatus according to claim 1, wherein recording is performed on a medium. The control unit cannot store a part of the management table of the file related to the deletion instruction in the memory after the directory information of the file related to the deletion instruction is read from the recording medium and stored in the memory. If
The file size indicated by the directory information stored in the memory is changed based on the size that can be stored in the memory in the management table, and is stored in the memory from the first cluster from the file management table according to the deletion instruction. The cluster number after the number of possible management table entries is detected, the leading cluster number indicated by the directory information is changed to the detected cluster number, the changed directory information is recorded on the recording medium,
From the recording medium, in the management table of the file related to the deletion instruction, from the first cluster before the change to the management table entry including the first cluster number after the change is read and stored in the memory,
2. The recording according to claim 1, wherein each management table entry of the management table of the portion stored in the memory is changed to a value indicating unused, and the changed management table is recorded on the recording medium. Playback device. The recording medium control means records a file, directory information indicating the file size of the file, and a management table indicating a use state of each cluster in the recording medium, on the recording medium having a plurality of clusters, and the recording A recording medium control step of reading the directory information and the management table from a medium, reading the file from the recording medium based on the read directory information and the management table, and reproducing the file;
A storing step in which the control unit stores the directory information and the management table read from the recording medium in a memory;
The control unit changes the directory information and management table stored in the memory in response to an instruction to delete the file recorded on the recording medium, and the changed directory information and management table are changed by the recording medium control unit. And a control step for recording on the recording medium,
In the control step, the control unit reads directory information of the file related to the deletion instruction from the recording medium and stores it in the memory, and then stores a part of the management table of the file related to the deletion instruction in the memory. If the file cannot be stored, the file size indicated by the directory information stored in the memory is changed based on the size of the portion of the management table that can be stored in the memory, and the file is recorded on the recording medium, and the deletion A portion of the file management table corresponding to the instruction is read from the recording medium and stored in the memory, the management table of the portion stored in the memory is changed to an unused state, and the recording medium is stored. And a recording / reproducing apparatus control method.   The program for making a computer perform each step in the control method of the recording / reproducing apparatus of Claim 4.

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