JP2004078490A - Recording device and method, reproducing device and method, recording medium and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable the information indicating the abnormal termination of the recording to remain, and to replay the data stream of an image recorded before the recording is abnormally terminated. <P>SOLUTION: In a step S14, a CPU checks a file size of each file of a directory entry copied on a storage DRAM for FAT, to determine whether the abnormal termination caused by the dying of battery is generated or not. Concretely, in a case when a specific dummy value is recorded as the file size, the generation of the abnormal termination is determined. When the generation of the abnormal termination is determined in the step S14, a processing is advanced to a step S15, where the CPU restores a part corresponding to abnormally terminated files of the directory entry of the storage DRAM for FAT and FAT, and overwrites the directory entry and FAT of an information recording medium. This invention can be applied to a hard disc recorder. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a recording device and method, a reproducing device and method, a recording medium, and a program, and more particularly to a method of recording and reproducing a data file on an information recording medium according to a FAT (File Allocation Table) system. The present invention relates to a preferable recording device and method, a reproducing device and method, a recording medium, and a program.
[0002]
[Prior art]
Conventionally, as a format for recording and reproducing a data file on an information recording medium such as a hard disk, the FAT method has been known. The FAT method is supported by a personal computer equipped with an OS (Operating System) such as MS-DOS, WINDOWS (registered trademark) or the like, and can be said to be the most popular file format method. .
[0003]
The FAT method will be described. As shown in FIG. 1, the recording area of the information recording medium is divided into physical recording units called sectors. Each sector has a predetermined capacity (for example, 512 bytes), and a sector address is given to each sector. Access to the information recording medium is performed in sector units.
[0004]
The recording area of the information recording medium is divided into logical recording units called clusters each composed of a predetermined number of sectors. Each cluster is assigned a cluster address. Reading and writing of files from and to the information recording medium are performed in cluster units.
[0005]
That is, when the size of a file to be recorded is larger than the capacity of one cluster, the file is divided into a plurality of clusters and recorded. Conversely, if the size of the file to be recorded is smaller than the capacity of one cluster, only that file is recorded in one cluster.
[0006]
In a predetermined recording area of the information recording medium, a file allocation table (hereinafter referred to as FAT) which is referred to and updated when recording or reading a file, and a directory entry are recorded.
[0007]
Note that management information is recorded in the first sector of the information recording medium. The management information includes the capacity of the information recording medium, information indicating how many sectors each cluster is composed of, the cluster address of the cluster where the FAT table is recorded, the cluster address of the cluster where the directory entry is recorded, and the like. included.
[0008]
FIG. 2 shows an example of the FAT. The FAT is provided with spaces corresponding to all the clusters of the information recording medium, and each space is assigned a FAT address.
[0009]
In the space of the FAT address 0, information indicating whether the cluster of the cluster address CL0 is empty or has been used is recorded. When there is data continuing from the data recorded in the cluster of the cluster address CL0, the cluster address of the cluster in which the continuing data is recorded is recorded as the information indicating that the data has been used. If there is no data continuing from the data recorded in the cluster with the cluster address CL0, an end mark (EOF) is recorded which means that the file ends with the data recorded in the cluster with the cluster address CL0. .
[0010]
Similarly, in the spaces of the FAT addresses 1, 2, 3,..., Information indicating whether the cluster of the cluster address CL1, 2, 3,.
[0011]
FIG. 3 shows an example of a directory entry. The directory entry records the file name, extension, attribute, reserved area, file creation time, file creation date, last access date, start cluster address, update date and time, and file size for each file. .
[0012]
For example, as shown in FIG. 4, when a file A having a size that fits in 5 or more and 6 or less clusters is recorded, the FAT is referred to, an empty cluster is sequentially searched, and the file A is stored there. It is divided and recorded. FIG. 4 shows a state where the six divided files A-1 to A-6 are recorded in the clusters having the cluster addresses CL10, CL11, CL12, CL15, CL20, and CL18, respectively.
[0013]
In this case, in the directory entry, the cluster address CL10 is recorded as the cluster address of the start cluster of the file A.
[0014]
In the FAT, as shown in FIG. 5, a cluster address CL11 is recorded in the space of the FAT address 10, a cluster address CL12 is recorded in the space of the FAT address 11, and a cluster address CL is recorded in the space of the FAT address 12. CL15 is recorded, the cluster address CL20 is recorded in the space of the FAT address 15, the cluster address CL18 is recorded in the space of the FAT address 20, and the EOF is recorded in the space of the FAT address 18.
[0015]
As described above, the FAT and directory entry updated at the time of recording the file are used when the file is read.
[0016]
For example, when the file A is read, first, the directory entry is referred to, the starting cluster (the cluster address CL10 in this case) of the file A is read, and the file A-1 is read from the cluster of the cluster address CL10. Is read.
[0017]
Next, referring to the FAT, the information (in this case, the cluster address CL11) recorded in the space of the FAT address 10 is read, and the file A-2 is read from the cluster of the cluster address CL11. Next, information (in this case, the cluster address CL12) recorded in the space of the FAT address 11 is read, and the file A-3 is read from the cluster of the cluster address CL12.
[0018]
Thereafter, in the same manner, the files A-4 to A-6 are sequentially read from the cluster of the cluster addresses CL15, CL20, and CL18, and the information recorded in the space of the FAT address 18 is read. Therefore, the data reading is completed. By the processing so far, the files A-1 to A-6 constituting the file A have been read.
[0019]
As described above, when reading a file, the FAT is frequently referred to in order to specify the next cluster to be read. Similarly, at the time of recording a file, the FAT is frequently referred to in order to search for a free cluster, and each time data is recorded in a cluster, the FAT is used in a space of the FAT corresponding to the cluster in which the data is recorded. Completed information is recorded.
[0020]
As described above, when a file is recorded and read, access to the FAT frequently occurs. Therefore, in the conventional device, in order to speed up the processing, the FAT recorded on the information recording medium is deleted. Copying to a RAM (Random Access Memory) or the like, and referring to or updating the copied FAT is performed.
[0021]
FIG. 6 shows an example of the configuration of such a conventional video recording device.
[0022]
In this video recording apparatus, a video input unit 1 is composed of a CCD (Charge Coupled Device) camera or the like, shoots a subject, and sequentially outputs obtained video signals to a video compression processing unit 2. The video compression processing unit 2 encodes the video signal input from the video input unit 1 using the MPEG (Moving Pictures Experts Group) 2 method or the like, and converts the obtained data stream via the bus 3 into the recording / reproducing unit 4. Output to Further, the video compression processing unit 2 decodes data input from the recording / reproducing unit 4 via the bus 3 and outputs the obtained video signal to the display unit 8.
[0023]
The recording / reproducing unit 4 buffers the data stream input from the video compression processing unit 2 via the bus 3 and records the data stream in a cluster of a cluster address specified by a CPU (Central Processing Unit) 6. Further, the recording / reproducing unit 4 reads data recorded in the cluster of the designated cluster address from the CPU 6 and outputs the data to the video compression processing unit 2 via the bus 3.
[0024]
During reproduction, the CPU 6 outputs a read command and a cluster address of a cluster from which data is read to the recording / reproducing unit 4 based on the directory entry and the FAT copied from the information recording medium 5 to the FAT storage RAM 7 during reproduction. I do. Also, at the time of recording, the CPU 6 searches for an empty cluster based on the FAT copied from the information recording medium 5 to the FAT storage RAM 7 and sends a write (Write) command and data to the recording / reproducing unit 4. Outputs the cluster address of the cluster in which is written. Further, the CPU 6 updates the directory entry and the FAT copied to the FAT storage RAM 7 at the time of recording, and overwrites the directory entry and the FAT of the information recording medium 5 at the end of the recording.
[0025]
Usually, a volatile RAM is used as the FAT storage RAM 7. Volatile RAMs have the disadvantage that stored data (such as FAT) are erased when the power is turned off, but have a longer lifespan than that of non-volatile EEPROMs (Electrically Erasable Programmable ROMs). There is. The display unit 8 displays the video of the video signal output from the video compression processing unit 2.
[0026]
Next, the operation of the CPU 6 during recording will be described with reference to a flowchart in FIG. This operation is started, for example, when a recording instruction is issued from the user.
[0027]
In step S1, the CPU 6 controls the recording / reproducing unit 4 to read out the FAT from the information recording medium 5 and store it in the FAT storage RAM 7. Further, the CPU 6 outputs a control signal for instructing each unit to start a recording process. In response to the control signal, for example, the video input unit 1 starts shooting and starts outputting the obtained video signal to the video compression processing unit 2. In the video compression process 2, encoding of the video signal input from the video input unit 1 is started, and output of the obtained data stream to the recording / reproducing unit 4 is started.
[0028]
In step S2, the CPU 6 controls the recording / reproducing unit 4 to read a directory entry from the information recording medium 5 and store the directory entry in the FAT storage RAM 7.
[0029]
In step S3, the CPU 6 refers to the FAT in the storage RAM 7 to search for one free cluster. In step S4, the CPU 6 outputs the cluster address and the write command of the free cluster searched in step S3 to the recording / reproducing unit 4. In response to the write command, the recording / reproducing unit 4 records the data buffered in the designated cluster.
[0030]
In step S5, the CPU 6 updates the FAT in the FAT storage RAM 7. Specifically, the used information is recorded in the FAT space corresponding to the cluster in which the data has been recorded.
[0031]
In step S6, the CPU 6 determines whether or not the end of the data stream in which the video signal is encoded has been recorded on the information recording medium 5, for example, in response to a recording end instruction from the user. Until it is determined that the end of is recorded, the process returns to step S3, and the subsequent processes are repeated.
[0032]
Thereafter, if it is determined in step S6 that the end of the data stream has been recorded, the process proceeds to step S7. In step S7, the CPU 6 updates the FAT and the directory entry in the FAT storage RAM 7. Specifically, the EOF is recorded in a space corresponding to the cluster in which the end of the data stream of the FAT is recorded, and information about the file recorded this time (file name, extension, start cluster, file size, etc.) is recorded in the directory entry. ).
[0033]
In step S8, the CPU 6 controls the recording / reproducing unit 4 to overwrite and save the FAT and the directory entry in the FAT storage RAM 7 updated in step S7 on the information recording medium 5. This concludes the description of the recording operation by the CPU 6.
[0034]
[Problems to be solved by the invention]
By the way, for example, in a video recording / reproducing apparatus such as a video camera carried by a user, the battery runs out during recording, or the battery is accidentally pulled out, so that the power supply to the apparatus is lost. It can happen that the supply is cut off.
[0035]
Therefore, if a situation such as running out of the battery occurs after the recording is started and before the processing of step S8 is completed, the data stream up to that point is recorded in which cluster and in what order. Since the latest FAT indicating whether or not the data has been erased disappears from the volatile FAT storage RAM 7, although the data stream of the video up to the time such as when the battery runs out is recorded on the information recording medium 5, There was a problem that it became impossible to reproduce it.
[0036]
If a non-volatile electrically erasable programmable ROM (EEPROM) or the like is used as the FAT storage RAM 7, it is possible to prevent the latest FAT from being erased even if a situation such as running out of battery occurs. However, as described above, a nonvolatile EEPROM or the like has a shorter life than a volatile RAM, and is not suitable for practical use.
[0037]
Further, if a non-volatile EEPROM or the like is used as the FAT storage RAM 7, considering that a removable disk that can be inserted and removed is used as the information recording medium 5, the user can store the FAT stored in the FAT storage RAM 7 with the FAT storage RAM 7. However, it may not be possible to grasp the correspondence with a plurality of removable disks.
[0038]
Therefore, for the purpose of temporarily storing the directory entry and the FAT read from the information recording medium, it is expected that the RAM having the excellent performance will be used in the future.
[0039]
The present invention has been made in view of such a situation, and even if a situation such as running out of battery occurs during recording, it is possible to reproduce a data stream of a video recorded up to that point. The purpose is to do.
[0040]
[Means for Solving the Problems]
A recording device according to the present invention includes a reading unit that reads a directory entry and a FAT from an information recording medium, a storage unit that stores the directory entry and the FAT read by the reading unit, and a FAT that is stored by the storage unit. A search unit for searching for an empty cluster of the information recording medium, a recording unit for recording a data file in an empty cluster of the information recording medium searched by the search unit, and a storage unit corresponding to the recording process by the recording unit. A first rewriting means for rewriting the stored FAT, and a dummy value is written in a predetermined item of the directory entry stored by the storage means and a dummy value is written in the predetermined item at the start of recording of the data file. The information recorded on the information recording medium is recorded using the directory entry. First updating means for updating the directory entry stored therein, and at the end of recording of the data file, correcting a predetermined item of the directory entry stored by the storage means to a true value and changing the predetermined item to a true value. Second updating means for updating the directory entry recorded on the information recording medium by using the directory entry corrected in the above manner, and using the FAT rewritten by the first rewriting means at the end of recording the data file. And a second rewriting means for rewriting a directory entry recorded on the information recording medium.
[0041]
The predetermined item may be a file size item.
[0042]
The second rewriting means periodically records the data file on the information recording medium by using the FAT stored by the storage means rewritten by the first rewriting means at the end of the recording of the data file and periodically. Directory entries can be rewritten.
[0043]
The recording apparatus according to the present invention includes a detecting unit that detects a bad data file in the information recording medium by checking a predetermined item of a directory entry stored by the storing unit, and a detecting unit that detects the bad data file. , Correcting a portion corresponding to the bad data file of the FAT, and correcting a value of a predetermined item of the directory entry.
[0044]
A recording method according to the present invention includes a reading step of reading a directory entry and a FAT from an information recording medium, a storing step of storing the directory entry and the FAT read in the processing of the reading step, and a FAT stored in the processing of the storing step. , A search step of searching for an empty cluster of the information recording medium, a recording step of recording a data file in an empty cluster of the information recording medium searched in the processing of the search step, and a processing of the recording step. A first rewriting step of rewriting the FAT stored in the processing of the storage step, and, at the start of recording of the data file, writing a dummy value in a predetermined item of the directory entry stored in the processing of the storage step, and Directory entry that wrote a dummy value to the item A first update step of updating a directory entry recorded on the information recording medium by using a file, and when the recording of the data file is completed, a predetermined item of the directory entry stored in the processing of the storage step is set to true. A second update step of updating the directory entry recorded on the information recording medium by using the directory entry in which the predetermined item is corrected to a true value and the predetermined item is corrected to a true value; A second rewriting step of rewriting a directory entry recorded on the information recording medium using the FAT rewritten in the processing of the first rewriting step.
[0045]
The program of the first recording medium of the present invention includes a reading step of reading a directory entry and a FAT from an information recording medium, a storing step of storing the directory entry and the FAT read in the processing of the reading step, and a processing of the storing step. A search step of searching for an empty cluster of the information recording medium with reference to the FAT stored in the step (a), a recording step of recording a data file in an empty cluster of the information recording medium searched in the processing of the search step, and In response to the processing, a first rewriting step of rewriting the FAT stored in the storage step processing, and at the start of recording of the data file, a dummy value is added to a predetermined item of the directory entry stored in the storage step processing. And write a dummy value to the specified item A first updating step of updating the directory entry recorded on the information recording medium using the directory entry, and when the recording of the data file is completed, a predetermined item of the directory entry stored in the processing of the storage step is set to true. And a second update step of updating the directory entry recorded on the information recording medium by using the directory entry in which the predetermined item has been corrected to the true value. And a second rewriting step of rewriting a directory entry recorded on the information recording medium using the FAT rewritten in the processing of the first rewriting step.
[0046]
A first program of the present invention is stored in a reading step of reading a directory entry and a FAT from an information recording medium, a storing step of storing the directory entry and the FAT read in the processing of the reading step, and a storing step. A search step of searching for an empty cluster of the information recording medium with reference to the retrieved FAT, a recording step of recording a data file in an empty cluster of the information recording medium searched in the processing of the search step, and a processing of the recording step. A first rewriting step of rewriting the FAT stored in the processing of the storage step, and writing a dummy value to a predetermined item of the directory entry stored in the processing of the storage step at the start of recording of the data file; The directory in which a dummy value has been written to the specified item A first update step of updating the directory entry recorded on the information recording medium by using the re-entry, and when the recording of the data file is completed, a predetermined item of the directory entry stored in the processing of the storage step is set to true. And a second update step of updating the directory entry recorded on the information recording medium by using the directory entry in which the predetermined item has been corrected to the true value. And a second rewriting step of rewriting the directory entry recorded on the information recording medium using the FAT rewritten in the processing of the first rewriting step.
[0047]
A reproducing apparatus according to the present invention comprises: a reading unit that reads a directory entry and a FAT from an information recording medium; a storage unit that stores the directory entry and the FAT read by the reading unit; A check means for detecting a bad data file in the information recording medium by examining the item, and when the bad data file is detected by the detecting means, a portion corresponding to the bad data file in the FAT is corrected and a predetermined directory entry is determined. And a correction unit for correcting the value of the item.
[0048]
The predetermined item may be a file size item.
[0049]
The detecting means may detect a defective data file in the information recording medium based on whether a dummy value is written in a predetermined item of the directory entry stored by the storage means.
[0050]
A reproducing method according to the present invention includes a reading step of reading a directory entry and a FAT from an information recording medium, a storing step of storing the directory entry and the FAT read in the processing of the reading step, and a directory stored in the processing of the storing step. A detection step of detecting a defective data file in the information recording medium by examining a predetermined item of the entry, and when a defective data file is detected in the processing of the detection step, a portion corresponding to the defective data file of the FAT is corrected. And modifying a value of a predetermined item of the directory entry.
[0051]
The program of the second recording medium according to the present invention includes a reading step of reading a directory entry and a FAT from an information recording medium, a storing step of storing the directory entry and the FAT read in the processing of the reading step, and a processing of the storing step. A detecting step of detecting a defective data file in the information recording medium by checking a predetermined item of the directory entry stored in the step (a). Modifying the corresponding part and modifying the value of a predetermined item of the directory entry.
[0052]
A second program according to the present invention is a storage medium that stores a directory entry and a FAT read out from the information recording medium, a storage step that stores the directory entry and the FAT read out in the processing of the reading step, and a storage step that stores the directory entry and the FAT. Detecting a bad data file in the information recording medium by examining a predetermined item of the directory entry, and, if a bad data file is detected in the processing of the detecting step, a portion corresponding to the bad data file in the FAT. And correcting the value of a predetermined item of the directory entry by a computer.
[0053]
In the recording apparatus, method, and program according to the present invention, at the start of recording of a data file, a dummy value is written in a predetermined item of a stored directory entry, and a dummy value is written in a predetermined item. The directory entry recorded on the information recording medium is updated using the entry. Further, at the end of recording of the data file, a predetermined item of the stored directory entry is corrected to a true value, and the predetermined item is recorded on an information recording medium using the directory entry corrected to a true value. Directory entry is updated.
[0054]
In the reproducing apparatus and method and the program according to the present invention, by checking a predetermined item of the stored directory entry, a bad data file in the information recording medium is detected. The portion corresponding to the bad data file is corrected, and the value of a predetermined item of the directory entry is corrected.
[0055]
The recording device may be an independent device, or may be a block that performs recording of the recording / reproducing device.
[0056]
The playback device may be an independent device or a block that executes playback of the recording / playback device.
[0057]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a video recording / reproducing apparatus according to an embodiment of the present invention will be described with reference to the drawings.
[0058]
The video recording / reproducing apparatus records a predetermined dummy value (for example, 0) in the file size item of the directory entry recorded on the information recording medium at the start of recording, and when the recording ends, The dummy value recorded in the file size item is updated to a true value. Therefore, if the recording is abnormally terminated due to, for example, running out of the battery before the recording is completed normally, a predetermined dummy value remains in the file size item of the directory entry. Thus, when the power is turned on, it is possible to determine whether or not the recording was abnormally terminated last time due to, for example, running out of the battery just by checking the file size item of the directory entry recorded on the information recording medium. it can.
[0059]
The video recording / reproducing apparatus restores the directory entry and the FAT when it is determined that the recording has been abnormally terminated last time. As a result, it is possible to reproduce the data recorded up to the time when the recording was abnormally terminated last time.
[0060]
FIG. 8 shows a configuration example of the video recording / reproducing apparatus. The CPU 21 controls the drive 22 via the bus 35, reads a control program stored in a recording medium 23 such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory, and reads the read control program; In response to the user's operation information input from the operation input unit 25 via the bus 35, it controls the operation start and end of each unit of the video recording / reproducing apparatus. Further, in particular, the CPU 21 outputs a cluster address together with a read command or a write command to the recording / reproducing unit 32 connected via the bus 35, and controls reading / writing of data from / to the information recording medium 33.
[0061]
The directory entry and the FAT recorded on the information recording medium 33 are copied to the volatile FAT DRAM 24. The directory entry and the FAT copied to the FAT DRAM 24 are referred to, updated, or repaired by the CPU 21.
[0062]
The operation input unit 25 includes a user interface such as an operation button, and is operated by a user (operation for setting a recording mode, operation for setting a playback mode, operation for instructing recording start, operation for instructing recording end, and the like). And outputs it to the CPU 21 via the bus 35 as operation information. The video input unit 26 includes a CCD camera or the like, captures an image of a subject, and sequentially outputs obtained video signals to a baseband processing unit 27.
[0063]
The baseband processing unit 27 performs a filtering process or the like on the video signals sequentially input from the video signal input unit 26, and outputs the video signals to the encoding unit 28. At the time of recording, the encoding unit 28 encodes, using the MPEG2 system or the like, the filtered video signal sequentially input from the baseband processing unit 27 using the MPEG2 method, and transmits the obtained data stream to the multiplexing unit 29. Output. Further, at the time of reproduction, the encoding unit 28 decodes the video data stream input from the multiplexing unit 29 and outputs the obtained video signal to the display unit 34.
[0064]
The multiplexing unit 29 multiplexes the video data stream input from the encoding unit 28 with the audio data stream input from the audio encoding unit (not shown) at the time of recording, thereby forming an MPEG2 format. A corresponding program stream (hereinafter, referred to as PS) is generated and output to the buffer unit 30. The multiplexing unit 29 acquires the PS read from the information recording medium 33 by the recording / reproducing unit 32 via the buffer unit 30 at the time of reproduction, and separates the PS into a video data stream and an audio data stream. Each is output to the encoding unit 28 and the audio encoding unit.
[0065]
The buffer unit 30 has a built-in DRAM 31. At the time of recording, every time PS data input from the multiplexing unit 29 accumulates in the DRAM 31 for one cluster, the buffer unit 30 requests the CPU 21 to write, and the writing succeeds. Until that time, the PS data stored in the DRAM 31 is held. The buffer unit 30 buffers the PS data input from the recording / reproducing unit 32 and supplies the data to the multiplexing unit 29 during reproduction.
[0066]
The recording / reproducing unit 32 reads the directory entry and the FAT recorded on the information recording medium 33 under the control of the CPU 21 and copies them to the FAT storage DRAM 24. Further, the recording / reproducing unit 32 overwrites and saves the updated directory entry and FAT on the FAT storage DRAM 24 on the information recording medium 33 under the control of the CPU 21.
[0067]
Further, at the time of recording, the recording / reproducing unit 32 reads out one cluster of PS data recorded in the DRAM 31 of the buffer 30 according to the write command input from the CPU 21, and reads the cluster data designated by the CPU 21 of the information recording medium 33. To record. Further, at the time of reproduction, the recording / reproducing unit 32 reads PS data recorded in the cluster specified by the CPU 21 of the information recording medium 33 and outputs the data to the buffer 30 according to a read command input from the CPU 21.
[0068]
The information recording medium 33 is composed of a hard disk or the like formatted based on the FAT method, and has a directory entry and a FAT recorded in a predetermined recording area.
[0069]
The display unit 34 displays an image of a video signal reproduced from the information recording medium 33 during reproduction. A control signal for each unit is transmitted from the CPU 21 to the bus 35. The video signal and the PS on which the video signal is encoded are directly communicated without passing through the bus 35.
[0070]
Next, a process when the power of the video recording / reproducing apparatus is turned on will be described with reference to a flowchart of FIG.
[0071]
In step S11, the CPU 21 determines whether or not the power is turned on, and waits until it is determined that the power is turned on. If it is determined that the power has been turned on, the process proceeds to step S12. In step S12, the CPU 21 controls the recording / reproducing unit 32 to copy the FAT recorded on the information recording medium 33 to the FAT storage DRAM 24. In step S13, the CPU 21 controls the recording / reproducing unit 32 to copy the directory entry recorded on the information recording medium 33 to the FAT storage DRAM 24.
[0072]
In step S14, the CPU 21 determines whether or not an abnormal end due to a dead battery or the like has occurred by checking the file size of each file of the directory entry copied from the information recording medium 33 to the FAT storage DRAM 24. I do. Specifically, when a predetermined dummy value is recorded in the file size of each file of the directory entry, it is determined that an abnormal end has occurred.
[0073]
If it is determined in step S14 that an abnormal end has occurred, the process proceeds to step S15. In step S15, the CPU 21 repairs the directory entry of the FAT storage DRAM 24 and the portion corresponding to the file which has been abnormally terminated in the FAT, and uses the restored directory entry and FAT to store the directory entry of the information recording medium 33 and the FAT. Overwrite. The directory entry and FAT repair processing will be described later with reference to FIGS.
[0074]
If it is determined in step S14 that the abnormal end has not occurred, the process of step S15 is skipped.
[0075]
In step S16, the CPU 21 determines whether the recording mode or the reproduction mode is set based on the operation information from the operation input unit 25. If it is determined that the recording mode has been set, the process proceeds to step S17, and the processing in the recording mode (described in detail with reference to FIG. 10) is executed.
[0076]
Conversely, when it is determined in step S16 that the reproduction mode has been set, the process proceeds to step S18, and the processing in the reproduction mode is executed. Specifically, a file to be reproduced is specified by the user, and by referring to the directory entry, the cluster address of the start cluster of the specified file is determined, and data reading is started. The cluster in which the continuation of the data is recorded is determined by referring to the data, and the data is read and read sequentially. This is the end of the description of the processing performed by the video recording / reproducing apparatus when the power is turned on.
[0077]
Next, the processing in the recording mode in step S17 will be described with reference to the flowchart in FIG.
[0078]
In step S21, the CPU 21 first refers to the FAT of the FAT storage DRAM 24 to search for an empty cluster for recording PS data. For example, when the FAT of the FAT storage DRAM 24 is in a state as shown in FIG. 11, the cluster of the cluster address CL10 is searched as a free cluster.
[0079]
In step S22, the CPU 21 determines whether or not the user has instructed to start recording based on the operation information from the operation input unit 25, and waits until it is determined that the user has instructed to start recording. If it is determined that the recording start has been instructed by the user, the process proceeds to step S23.
[0080]
In step S23, the CPU 21 records the file name, the starting cluster (the cluster address of the free cluster searched in step S21), and the dummy file size as information of the file to be recorded in the directory entry of the FAT storage DRAM 24. .
[0081]
In step S24, the CPU 21 controls the recording / reproducing unit 32 to copy (overwrite) the directory entry of the FAT storage DRAM 24 to the information recording medium 33.
[0082]
In step S25, the CPU 21 transmits a recording start command to each unit via the bus 35. In response to the recording start command, the video input unit 26 to the buffer unit 30 start their respective operations. Thus, the data of the PS input from the multiplexing unit 29 starts to accumulate in the DRAM 31 of the buffer unit 30.
[0083]
In step S26, the CPU 21 determines whether or not there is a write request from the buffer unit 30, and if it is determined that there is no write request, the process proceeds to step S27. In step S27, the CPU 21 refers to the FAT of the FAT storage DRAM 24 and searches for a free cluster for recording data next. For example, when the FAT of the FAT storage DRAM 24 is in a state as shown in FIG. 11, the cluster of the cluster address CL11 is searched as a free cluster.
[0084]
Then, the data of the PS input from the multiplexing unit 29 for one cluster accumulates in the DRAM 31 of the buffer unit 30, and the processes of steps S26 and S27 are repeated until the buffer unit 30 issues a write request to the CPU 21. It is.
[0085]
If it is determined in step S26 that there is a write request from the buffer unit 30, the process proceeds to step S28. In step S28, the CPU 21 notifies the recording / playback unit 32 of the cluster address of the free cluster together with the write command.
[0086]
In accordance with the write command input from the CPU 21, in step S 29, the recording / reproducing unit 32 reads one cluster of PS data recorded in the DRAM 31 of the buffer 30, and reads an empty cluster designated by the CPU 21 of the information recording medium 33. Write to.
[0087]
In step S30, the CPU 21 updates the FAT of the FAT storage DRAM 24 in accordance with the processing in step S29. In step S31, the CPU 21 controls the recording / reproducing unit 32 to copy (overwrite) the updated FAT in the FAT storage DRAM 24 to the information recording medium 33. Note that the process of step S31 does not necessarily have to be executed every time after the process of step S30. For example, it may be executed periodically (for example, every few seconds to several minutes).
[0088]
In step S32, the CPU 21 determines that the end of the PS data has been recorded on the information recording medium 33 in response to an instruction from the user to end the recording. If it is not determined that the end of the PS data has been recorded, the process returns to step S26, and the subsequent processes are repeated.
[0089]
Thereafter, if it is determined in step S32 that the end of the PS data has been recorded, the process proceeds to step S33. At the stage of proceeding to the processing of step S33, the FAT of the FAT storage DRAM 24 is, for example, as shown in FIG. 12, a space for the cluster in which the end of the PS data is written (in FIG. Space) is in a state where EOF is written.
[0090]
In step S33, the CPU 21 records a correct value in a file size item in which a dummy value is currently recorded in the directory entry of the FAT storage DRAM 24.
[0091]
In step S33, the CPU 21 controls the recording / reproducing unit 32 to copy (overwrite) the updated directory entry of the FAT storage DRAM 24 to the information recording medium 33. This is the end of the description of the processing in the recording mode.
[0092]
By the way, in the above-described recording mode processing, during the processing of steps S26 to S33, for example, when a situation such as running out of the battery occurs and the recording mode processing is interrupted (that is, abnormal termination) Occurs)), in the directory entry of the information recording medium 33, information of a file in which a predetermined dummy value is recorded in the file size item remains.
[0093]
Based on this information, in the processing of step S14 in FIG. 9 described above, it is determined whether or not an abnormal end has occurred.
[0094]
Next, the directory entry and FAT repair processing in step S15 in FIG. 9 will be described.
[0095]
Here, it is assumed that the recording of the FAT corresponding to the abnormally terminated file is in a state as shown in FIG. That is, according to the FAT recorded on the information recording medium 33, the cluster of the cluster address CL10 is used, and the cluster of the cluster addresses CL11, CL12, and CL13 is already used. It is assumed that information indicating a space is recorded in the corresponding space. When the FAT is in such a state, it is highly probable that the FAT has abnormally ended while data is being written to the cluster of the cluster address CL16, and thus the reliability of the data recorded in the cluster of the cluster address CL16 is low.
[0096]
There are two types of methods for repairing directory entries and FATs. The first restoration method allows the recorded data to be reproduced as much as possible, but has low data reliability. The second restoration method has a smaller amount of reproducible data than the first restoration method, but is a method with high data reliability.
[0097]
In the first restoration method, the EOF is recorded in a space of the FAT corresponding to the cluster address recorded in the last space among a series of spaces in which information used in the FAT is recorded. When the FAT shown in FIG. 13 is repaired by the first repair method, as shown in FIG. 14, the end is recorded in the space of the FAT corresponding to the cluster address CL16. As described above, when the FAT is restored, the total value of the cluster addresses CL10, CL11, CL12, CL13, and CL16 is recorded in the file size item of the directory entry.
[0098]
In the second repair method, the last space in a series of spaces in which used information is recorded in the FAT is rewritten to the end. When the FAT shown in FIG. 13 is repaired by the second repair method, the end is recorded in the space of the FAT for the cluster address CL13 as shown in FIG. As described above, when the FAT is restored, the total value of the cluster addresses CL10, CL11, CL12, and CL13 is recorded in the file size item of the directory entry.
[0099]
As described above, according to the video recording / reproducing apparatus to which the present invention is applied, even if power supply is suddenly cut off due to a battery exhaustion or the like, a file recorded up to that point can be reproduced. .
[0100]
In addition, as compared with the conventional video recording / reproducing apparatus, the processing that the video recording / reproducing apparatus to which the present invention is applied must be performed during recording includes writing a directory entry at the start of recording, and performing regular processing during recording. Only the process of copying the FAT table to the information recording medium does not impose a burden on the CPU.
[0101]
In the video recording / reproducing apparatus to which the present invention is applied, it is not necessary to record a special data file for detecting abnormal termination, so that handling of the file is not complicated.
[0102]
Further, since the information recording medium used by the video recording / reproducing apparatus to which the present invention is applied completely conforms to the normal FAT format, a general-purpose personal computer can directly access this information recording medium. However, if an abnormal termination has occurred, an error may occur if a general-purpose personal computer directly accesses the computer.
[0103]
Since the video recording / reproducing apparatus to which the present invention is applied can search for the abnormally terminated file only by checking the file size of the directory entry, this processing is immediately terminated.
[0104]
In the video recording / reproducing apparatus to which the present invention is applied, the FAT updated in the FAT storage DRAM 24 is regularly copied to the information recording medium. However, if this frequency is increased, the FAT cannot be restored after abnormal termination. Becomes smaller, but the processing at the time of recording becomes heavier. In other words, by adjusting the frequency of copying the FAT to the information recording medium periodically, tuning in accordance with the system performance (mainly the recording speed) and the resilience can be performed.
[0105]
The present invention can be applied not only to a device that records and reproduces a video signal as in the present embodiment, but also to a device that records all data on an information recording medium formatted in the FAT format. It is possible.
[0106]
Further, the present invention can be embodied as a reproducing apparatus capable of restoring a directory entry and a FAT recorded on an information recording medium.
[0107]
Incidentally, the series of processes described above can be executed by hardware, but can also be executed by software. When a series of processing is executed by software, a program constituting the software is installed in a computer (for example, CPU 21 in FIG. 8) incorporated in dedicated hardware, or by installing various programs, It is installed from a recording medium (for example, the recording medium 23 in FIG. 8) in, for example, a general-purpose personal computer that can execute various functions.
[0108]
As shown in FIG. 8, this recording medium is a magnetic disk (including a flexible disk) on which the program is recorded and an optical disk (CD-ROM (distributed) provided separately from the computer to provide the program to the user. Compact Disc-Read Only Memory, DVD (including Digital Versatile Disc), Magneto-Optical Disk (including MD (Mini Disc)), or package media including semiconductor memory, etc. It is provided with a ROM or a hard disk in which the program is recorded, which is provided to the user in a built-in state.
[0109]
In this specification, the steps of describing a program recorded on a recording medium include, in addition to processing performed in chronological order according to the described order, not only chronological processing but also parallel or individual processing. This includes the processing to be executed.
[0110]
Also, in this specification, a system refers to an entire device including a plurality of devices.
[0111]
【The invention's effect】
As described above, according to the present invention, when a situation such as running out of battery occurs during recording, information indicating that recording has been abnormally terminated can be left on the information recording medium. Further, according to the present invention, it is possible to reproduce the data stream of the video recorded by the time when the recording ends abnormally.
[Brief description of the drawings]
FIG. 1 is a diagram showing a physical recording unit and a logical recording unit of an information recording medium.
FIG. 2 is a diagram illustrating an example of a FAT.
FIG. 3 is a diagram illustrating an example of a directory entry.
FIG. 4 is a diagram showing a state where a file is divided into a plurality of clusters and recorded.
FIG. 5 is a diagram showing an example of a FAT corresponding to the state shown in FIG.
FIG. 6 is a block diagram illustrating an example of a configuration of a conventional video recording / reproducing device.
FIG. 7 is a flowchart illustrating an operation of the CPU of FIG. 6 during recording.
FIG. 8 is a block diagram illustrating a configuration example of a video recording / reproducing apparatus according to an embodiment of the present invention.
FIG. 9 is a flowchart illustrating the operation of the video recording / reproducing device of FIG. 8;
FIG. 10 is a flowchart illustrating processing in a recording mode in step S17 of FIG. 9;
FIG. 11 is a diagram illustrating an example of a FAT before recording is started.
FIG. 12 is a diagram showing an example of a FAT after recording has been completed normally.
FIG. 13 is a diagram illustrating an example of the FAT after the recording ends abnormally.
FIG. 14 is a diagram showing an example of a FAT restored by the first restoration method.
FIG. 15 is a diagram showing an example of a FAT restored by a second restoration method.
[Explanation of symbols]
Reference Signs List 21 CPU, 23 recording medium, 24 FAT DRAM, 32 recording / reproducing unit, 33 information recording medium

Claims (13)

In a recording apparatus that records a data file on an information recording medium according to the FAT method,
Reading means for reading a directory entry and a FAT from the information recording medium;
Storage means for storing the directory entry and the FAT read by the reading means;
Searching means for searching for an empty cluster of the information recording medium with reference to the FAT stored by the storing means;
Recording means for recording a data file in the free cluster of the information recording medium searched by the search means,
First rewriting means for rewriting the FAT stored by the storage means in response to a recording process by the recording means;
At the start of recording of the data file, a dummy value is written in a predetermined item of the directory entry stored by the storage means, and the directory entry in which the dummy value is written in the predetermined item is used, First updating means for updating the directory entry recorded on the information recording medium;
At the end of recording of the data file, a predetermined item of the directory entry stored by the storage unit is corrected to a true value, and the directory entry obtained by correcting the predetermined item to the true value is used. Second updating means for updating the directory entry recorded on the information recording medium;
A second rewriting means for rewriting the directory entry recorded on the information recording medium by using the FAT rewritten by the first rewriting means at the end of the recording of the data file. Recording device. The recording apparatus according to claim 1, wherein the predetermined item is a file size item. The second rewriting means uses the FAT stored by the storage means rewritten by the first rewriting means periodically at the end of the recording of the data file and periodically. 2. The recording apparatus according to claim 1, wherein the directory entry recorded in the directory is rewritten. Detecting means for detecting a bad data file in the information recording medium by checking a predetermined item of the directory entry stored by the storage means;
When the bad data file is detected by the detecting means, a correcting means for correcting a portion of the FAT corresponding to the bad data file and correcting a value of a predetermined item of the directory entry is further included. 2. The recording apparatus according to claim 1, wherein: In a recording method of a recording device that records a data file on an information recording medium according to a FAT method,
Reading a directory entry and a FAT from the information recording medium;
A storage step of storing the directory entry and the FAT read in the processing of the reading step;
A search step of searching for a free cluster of the information recording medium with reference to the FAT stored in the processing of the storage step;
A recording step of recording a data file in the free cluster of the information recording medium searched in the processing of the search step;
A first rewriting step of rewriting the FAT stored in the processing of the storage step, corresponding to the processing of the recording step;
At the start of recording of the data file, a dummy value is written in a predetermined item of the directory entry stored in the processing of the storing step, and the directory entry in which the dummy value is written in the predetermined item is used. A first updating step of updating the directory entry recorded on the information recording medium;
At the end of the recording of the data file, a predetermined item of the directory entry stored in the processing of the storing step is corrected to a true value, and the directory entry obtained by correcting the predetermined item to the true value is stored in the directory entry. Using the second update step of updating the directory entry recorded on the information recording medium,
A second rewriting step of rewriting the directory entry recorded on the information recording medium by using the FAT rewritten in the processing of the first rewriting step at the end of recording of the data file. Recording method characterized by the above-mentioned. A program for a recording device for recording a data file on an information recording medium according to the FAT method,
Reading a directory entry and a FAT from the information recording medium;
A storage step of storing the directory entry and the FAT read in the processing of the reading step;
A search step of searching for a free cluster of the information recording medium with reference to the FAT stored in the processing of the storage step;
A recording step of recording a data file in the free cluster of the information recording medium searched in the processing of the search step;
A first rewriting step of rewriting the FAT stored in the processing of the storage step, corresponding to the processing of the recording step;
At the start of recording of the data file, a dummy value is written in a predetermined item of the directory entry stored in the processing of the storing step, and the directory entry in which the dummy value is written in the predetermined item is used. A first updating step of updating the directory entry recorded on the information recording medium;
At the end of the recording of the data file, a predetermined item of the directory entry stored in the processing of the storing step is corrected to a true value, and the directory entry obtained by correcting the predetermined item to the true value is stored in the directory entry. Using the second update step of updating the directory entry recorded on the information recording medium,
A second rewriting step of rewriting the directory entry recorded on the information recording medium by using the FAT rewritten in the processing of the first rewriting step at the end of recording of the data file. A recording medium on which a computer-readable program is recorded. A computer that controls a recording device that records a data file on an information recording medium according to the FAT method;
Reading a directory entry and a FAT from the information recording medium;
A storage step of storing the directory entry and the FAT read in the processing of the reading step;
A search step of searching for a free cluster of the information recording medium with reference to the FAT stored in the processing of the storage step;
A recording step of recording a data file in the free cluster of the information recording medium searched in the processing of the search step;
A first rewriting step of rewriting the FAT stored in the processing of the storage step, corresponding to the processing of the recording step;
At the start of recording of the data file, a dummy value is written in a predetermined item of the directory entry stored in the processing of the storing step, and the directory entry in which the dummy value is written in the predetermined item is used. A first updating step of updating the directory entry recorded on the information recording medium;
At the end of the recording of the data file, a predetermined item of the directory entry stored in the processing of the storing step is corrected to a true value, and the directory entry obtained by correcting the predetermined item to the true value is stored in the directory entry. Using the second update step of updating the directory entry recorded on the information recording medium,
A second rewriting step of rewriting the directory entry recorded on the information recording medium using the FAT rewritten in the processing of the first rewriting step at the end of recording of the data file. A program characterized by executing In a reproducing apparatus for reproducing a data file recorded on an information recording medium according to the FAT method,
Reading means for reading a directory entry and a FAT from the information recording medium;
Storage means for storing the directory entry and the FAT read by the reading means;
Detecting means for detecting a bad data file in the information recording medium by checking a predetermined item of the directory entry stored by the storage means;
And correcting means for correcting a portion of the FAT corresponding to the bad data file and correcting a value of a predetermined item of the directory entry when the bad data file is detected by the detecting means. Playback device. 9. The reproducing apparatus according to claim 8, wherein the predetermined item is a file size item. The detecting unit detects a defective data file in the information recording medium based on whether a dummy value is written in a predetermined item of the directory entry stored by the storage unit. The playback device according to claim 8. In a reproducing method of a reproducing apparatus for reproducing a data file recorded on an information recording medium according to a FAT method,
Reading a directory entry and a FAT from the information recording medium;
A storage step of storing the directory entry and the FAT read in the processing of the reading step;
A detecting step of detecting a bad data file in the information recording medium by checking a predetermined item of the directory entry stored in the processing of the storing step;
And correcting the portion of the FAT corresponding to the bad data file and correcting the value of a predetermined item of the directory entry when the bad data file is detected in the processing of the detecting step. Characteristic playback method. A program for a reproducing apparatus for reproducing a data file recorded on an information recording medium according to the FAT method,
Reading a directory entry and a FAT from the information recording medium;
A storage step of storing the directory entry and the FAT read in the processing of the reading step;
A detecting step of detecting a bad data file in the information recording medium by checking a predetermined item of the directory entry stored in the processing of the storing step;
And correcting the portion of the FAT corresponding to the bad data file and correcting the value of a predetermined item of the directory entry when the bad data file is detected in the processing of the detecting step. A recording medium on which a computer readable program is recorded. A computer that controls a reproducing apparatus that reproduces a data file recorded on an information recording medium in accordance with the FAT method,
Reading a directory entry and a FAT from the information recording medium;
A storage step of storing the directory entry and the FAT read in the processing of the reading step;
A detecting step of detecting a bad data file in the information recording medium by checking a predetermined item of the directory entry stored in the processing of the storing step;
When the defective data file is detected in the processing of the detecting step, a correcting step of correcting a portion of the FAT corresponding to the bad data file and correcting a value of a predetermined item of the directory entry. A program characterized by being executed.

Images