JP3984100B2 - Video recording apparatus and video recording method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a video recording apparatus and a video recording method, and more particularly to a video recording apparatus and a video recording method for recording an MPEG2-encoded video on a recording medium such as a hard disk.
[0002]
[Prior art]
In recent years, attention has been focused on devices that encode MPEG2 encoded terrestrial TV broadcasts onto hard disks and DVD-RAM disks. When recording video to these devices, it is generally recorded as a file. When a general-purpose OS such as Linux is used as the OS (Operating System), the file system (file management and writing, The file system attached to the OS is also used for the part that controls reading).
[0003]
In this case, if a power failure occurs during recording or if the user accidentally disconnects the AC plug and a forced power cut occurs, the file restoration function of the OS file system will be available when the power is turned on the next time and the OS is started. The working file is repaired, but in the worst case, the file system itself may be destroyed. In recent years, a journaling file system that has a function to prevent inconsistencies and destruction of the file system from a sudden power interruption has started to be adopted.
[0004]
[Problems to be solved by the invention]
However, even when a journaling file system having a repair function is used as the file system in the above-mentioned conventional technology, only the consistency of the file management area (I-node) is guaranteed, and the data itself written in the file is Not guaranteed. This is because if the data itself is guaranteed, the efficiency such as the writing speed of the file system is lowered.
[0005]
FIG. 7 shows an outline of data of a recording target file when a power interruption occurs during recording. As shown in FIG. 7, the video data length recorded from the start of recording to the occurrence of power interruption, that is, the file length indicated by the management area, is normal until the middle of the file, but is random near the end of the file. Data is written. This phenomenon prevents duplication in the management area that manages the length of the file by duplicating the file, but the file data itself is written to the OS write buffer and hard disk. This is because the discharge of data contained in the cache is performed with a delay from the writing of the management area.
[0006]
In many cases, a video recording apparatus simultaneously writes an MPEG2 compressed video file of an input video and an index file that stores a GOP (Group of picture) position in the video file. In this case, meaningless data exists at the end of both the video file and the index file. If these files are used for reproduction as they are, there is a problem that a meaningless data portion of the video file cannot be decoded and a useless area on the recording medium is consumed. In addition, if meaningless data exists at the end of the index file, it indicates an impossible GOP position, and there is a possibility that reproduction may not be performed at all.
[0007]
The present invention solves these problems, and a video recording apparatus and a video recording capable of preventing wasteful consumption of recording capacity due to a video file and an index file of the video file and a reproduction error of these files. It is to provide a method.
[0008]
[Means for Solving the Problems]
In order to solve the above problems and achieve the object, a video recording apparatus and a video recording method of the present invention are configured as follows.
[0009]
(1) A video recording apparatus according to the present invention comprises a video file inspection / repair means for inspecting and repairing a video file, an index file inspection / repair means for inspecting and repairing an index file including index information of the video file, Recording means for recording the video file and the index file.
[0010]
(2) According to the video recording method of the present invention, the video file and the index file including the index information of the video file are inspected and repaired, and the video file and the index file are recorded.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
The present embodiment will be described below with reference to the drawings.
[0012]
FIG. 1 is a diagram showing a schematic configuration of a video recording apparatus according to the first embodiment of the present invention. The outline of the operation of this apparatus is as follows.
[0013]
The system control unit 102 receives an instruction 101 from the user and outputs a control instruction 103 to each unit. Specifically, first, the system control unit 102 receives a video input selection instruction. Thereby, the system control unit 102 outputs a control instruction 103 to each unit, and switches the input video to either the video from the tuner or the video from the line input. Next, the system control unit 102 receives a recording start instruction. The system control unit 102 activates the MPEG2 encoder 110 and the recording control unit 111. The MPEG2 encoder unit 110 receives the signal selected from the tuner input or the line input, performs MPEG2 compression, and sends it to the subsequent stage. When the recording control unit 111 is activated, the index file 118 and the video file 117 are opened, and the file names are notified to the file system 120.
[0014]
FIG. 2 is a diagram illustrating an example of the data structure of the index file 118. The index file 118 includes index information of the video file 117. The index information is information indicating the GOP position, for example. The video file 117 stores MPEG2 compressed digital data output from the MPEG2 encoder unit 110. The recording control unit 111 receives the MPEG2-compressed data transmitted from the MPEG2 encoder 110, checks the MPEG2 header, and writes the GOP position from the file head to the index file 118 when the GOP head is detected. The GOP head detection may be performed by notification from the MPEG2 encoder unit 110. Regardless of the detection of the GOP head, the MPEG2 compressed data is written to the video file 117. Each file writing is performed via the file system 120. This process is continued while recording continues.
[0015]
Finally, when the system control unit 102 receives an instruction 101 from the user, that is, a recording stop instruction, the system control unit 102 stops encoding to the MPEG2 encoder unit 110 and stops processing to the recording control unit 111. When receiving the encoding stop instruction, the MPEG2 encoding unit 110 stops data transmission to the subsequent stage. When receiving a recording stop instruction, the recording control unit 111 closes the video file 117 and the index file 118.
[0016]
In the video recording apparatus according to the first embodiment, for example, the restoration process is performed by the system control unit 102 at the time of activation. An outline flowchart of the repair process is shown in FIG. The system control unit 102 extracts a set of video file names and index file names of all recorded titles stored (ST101). Here, since the restoration of all the titles has not been completed (ST102, NO), one set of video file name and index file name is taken out one by one (ST103), the index file restoration unit 113, the mutual restoration unit 114, and the video file. The repair unit 115 is called in order (ST104, ST105, ST106). This process is performed for all pairs of video file names and index file names.
[0017]
First, the index restoration unit 113 is activated. FIG. 4 shows a process flowchart of the index restoration unit 113. For example, it is assumed that the offset value from the top of each GOP video file in the index file is stored in 8 bytes. Each of these 8 bytes is called a record, and the value of each record in the index file is represented as index [0], index [1],..., Index [N]. N represents the total record length. The value of each record increases monotonically because the location of the GOP in the video file is stored in order. It is impossible that the value index [i + 1] of the next record is smaller than the value index [i] of a certain record. First, the index restoration unit 113 acquires the file size of the index file and substitutes it into fSize (ST201). Next, the remainder of fSize / 8 is obtained (ST202), and if it is 0 (ST203, YES), it proceeds to the next without performing anything. If it is other than 0 (ST203, NO), the size of the index file is truncated by the remaining length (ST204). Next, 0 is assigned to variable I (ST205), 8 bytes are read from the index file, and assigned to index [0] (ST206). Enter the loop from here. 8 bytes are read from the index file and assigned to index [I + 1] (ST207). If index [I] <index [I + 1] (ST208, YES), I is incremented by 1 (ST209). When I is larger than N−1 (ST211, NO), the process exits the loop and ends, otherwise, the process returns to the loop head (ST207). When index [I] ≧ index [I + 1] is satisfied (ST208, NO), it is determined that abnormal data is written, and index files after index [I + 1] are truncated (ST210). The repair process ends. The processing of the index restoration unit 113 ensures that each record of the index file is monotonously increasing.
[0018]
Next, the mutual repair unit 114 is activated. FIG. 5 shows a process flowchart of the mutual repair unit 114. In this embodiment, for simplicity, each pack length is fixed to 2048 bytes, and Pack Hader length is also fixed to 14 bytes. Furthermore, it is assumed that there is always a System Header in the first pack of the GOP. In the case of this structure, if each pack is examined and the data from the 15th byte to the 18th byte is 0x00, 0x00, 0x01, 0xbb (System Header start code), it can be determined as the GOP head. First, 0 is substituted for variable I (ST301). Enter the loop from here. 8 bytes are read from the index file (ST302) and assigned to index [0]. Next, the video file is seeked by index [0] from the top (ST303), 1024 bytes are read and substituted into buffer (ST304). If Buffer [14] == 0 and buffer [15] == 0 and buffer [16] == 1 and buffer [17] == 0xbb, it is determined as a normal GOP (ST305, YES), and I is incremented by 1 (ST306) ). When I becomes N or more (ST307, NO), the process exits the loop and ends (ST307, YES), and returns to the loop head (ST302). Buffer [14]! = 0 or buffer [15]! = 0 or buffer [16]! = 1 or buffer [17]! = If 0xbb, it is judged as an abnormal GOP (ST305, NO), and the index of the video file [I] and subsequent portions are deleted (ST308), the I-th and subsequent records in the index file are deleted (ST309), and the correction process is terminated.
[0019]
Finally, the video file restoration unit 115 is activated. In the video file recording unit, only the final GOP is inspected to confirm in detail whether it complies with the MPEG2 standard. The purpose of the video file restoration unit 115 is that the mutual restoration unit 114 only confirms the GOP head part, so that the validity of the GOP up to immediately before the final GOP can be guaranteed, but the GOP head exists for the last GOP. Can only be guaranteed. Accordingly, the final GOP needs to be inspected by the video file restoration unit 115. For example, it is determined whether the final GOP is a multiple of 2048 bytes (a multiple of the pack length). If it is not a multiple of the pack length, the remainder is discarded.
[0020]
When a power outage occurs during video recording in the video recording device and the power supply to the system is cut off, the video file and index file already recorded on the recording medium are repaired, Inconsistent GOPs between index files and incomplete GOPs are removed. As a result, it is possible to save as much as possible the titles that were recorded before the power was turned off. Furthermore, since there is no inconsistency between the video file and the index file, there is no occurrence of a problem in reproduction. In addition, a restoration process is performed on all recorded titles at the time of startup, and this process always maintains the consistency of all titles.
[0021]
The format of the index file is not limited to the format described above. If the position of each GOP in the video file is stored in some form, the above-described restoration processing in the video recording apparatus can be realized.
[0022]
The video recording apparatus described above detects that a power interruption has occurred during recording at the next start-up even if a power interruption occurs during recording execution. Each file can be repaired independently and repaired by mutual consistency, and abnormal data in the video file and the index file can be cut off to make a normally reproducible file.
[0023]
FIG. 6 is a diagram showing a schematic configuration of a video recording apparatus according to the second embodiment of the present invention. An outline of the operation of this apparatus will be described with a focus on differences from the video recording apparatus shown in FIG.
[0024]
In this video recording apparatus, when the system control unit 102 receives a recording start instruction from a user, the system control unit 102 starts the MPEG2 encoder 110 and starts the recording control unit 111, in addition to the status recording unit 112. Notify the “Recording” information. The status recording unit 112 writes the “recording flag” in the recording medium 116 or the nonvolatile memory based on the “recording” information received from the system control unit 110 so that the information is not lost even when the power is turned off.
[0025]
Next, when the system control unit 102 receives a recording stop instruction from the user, the system control unit 102 notifies the status recording unit 112 of “recording stop” information. The status recording unit 112 determines that the recording has ended normally only when the “recording stop” notification from the system control unit 102 is received, and clears the “recording flag” held in the recording medium 116. As described above, the “recording” flag is ON only when recording is being performed in the system.
[0026]
If a power failure occurs or the user unplugs the power plug accidentally during the recording state, the entire system is stopped because the power supply to the entire system is cut off. Thereafter, after the power is turned on for the first time and the system is started, the system control unit 102 inquires of the state control unit 112 about the necessity for repair. The system control unit 102 determines whether restoration is necessary or not based on the “recording flag” recorded in the recording medium 116 or the nonvolatile memory. If the “recording flag” exists, it is determined that an unexpected power interruption has occurred during recording, and the system control unit 102 is notified of the necessity of repair and the file name to be repaired. If the “recording flag” is cleared, the recording is normally completed and there is no need for repair, so the system control unit 102 is notified that repair is not required.
[0027]
When the system control unit 102 receives a notification indicating that repair is necessary, the system control unit 102 starts file repair processing for only the file to be repaired. The file restoration process of the recording / reproducing apparatus shown in FIG. 6 is the same as the file restoration process of the video recording / reproducing apparatus shown in FIG.
[0028]
The video recording apparatus according to the second embodiment makes it possible to activate the repair process only when necessary, and the system can be activated quickly.
[0029]
Note that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention in the implementation stage. In addition, the embodiments may be appropriately combined as much as possible, and in that case, the combined effect can be obtained. Further, the above embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, even if some constituent requirements are deleted from all the constituent requirements shown in the embodiment, the problem described in the column of the problem to be solved by the invention can be solved, and the effect described in the column of the effect of the invention Can be obtained as an invention.
[0030]
【The invention's effect】
According to the present invention, it is possible to provide a video recording apparatus and a video recording method capable of preventing wasteful consumption of recording capacity due to a video file and an index file of the video file and a reproduction error of these files.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a schematic configuration of a video recording apparatus according to a first embodiment of the present invention.
FIG. 2 is a diagram illustrating an example of a data structure of an index file.
FIG. 3 is a flowchart showing an outline of restoration processing of a video file and an index file.
FIG. 4 is a flowchart showing index file repair processing by the index file repair unit.
FIG. 5 is a flowchart illustrating video file and index file repair processing by the mutual repair unit.
FIG. 6 is a block diagram showing a schematic configuration of a video recording apparatus according to a second embodiment of the present invention.
FIG. 7 is a diagram showing an outline of data of a video file that is affected by a power interruption during recording.
[Explanation of symbols]
102 ... System control unit 110 ... MPEG encoder 111 ... Recording control unit 112 ... Status recording unit 113 ... Index file restoration unit 114 ... Mutual restoration unit 115 ... Video file restoration unit 116 ... Recording medium 120 ... File system

Claims (4)

A meaningless data at the end of both the video file and the index file that stores the location of the picture group in this video file, which has a function to guarantee the consistency of information in the file management area from sudden power interruption A video recording device for deleting
The file size of the index file composed of records in units of 8 bytes is acquired, the acquired file size is divided by 8 corresponding to the units of bytes , the index file is truncated by the remaining length, and each monotonously increasing An index file processing means that examines the value of the record and truncates the records that do not meet the monotonically increasing condition,
Based on the index file processed by the index file processing means, determine whether the picture group is normal or abnormal based on whether or not a predetermined code is present at a predetermined position of the leading pack constituting the picture group in the video file, A file mutual processing means for deleting a picture group after the picture group determined to be abnormal, and further deleting a record indicating the picture group after the picture group determined to be abnormal in the index file;
It is checked whether the last picture group in the video file processed by the file mutual processing means is composed of a multiple of a predetermined number of bytes, and if there is a remainder instead of a multiple of the predetermined number of bytes, Video file processing means to cut off the remainder,
Recording means for recording the index file and the video file processed by the index file processing means, the file mutual processing means, and the video file processing means;
A video recording apparatus comprising: Status recording means for recording information indicating recording based on receipt of a recording start instruction, and clearing information indicating recording based on reception of a recording stop instruction;
Based on the presence of information indicating that recording is in progress recorded by the status recording means, the index file processing means, the file mutual processing means, the meaning of the end of both the index file and the video file by the video file processing means Control means for executing processing for deleting unnecessary data;
The video recording apparatus according to claim 1, further comprising: A meaningless data at the end of both the video file and the index file that stores the location of the picture group in this video file, which has a function to guarantee the consistency of information in the file management area from sudden power interruption A video recording method for deleting
The file size of the index file composed of records in units of 8 bytes is acquired, the acquired file size is divided by 8 corresponding to the units of bytes , the index file is truncated by the remaining length, and each monotonously increasing Check the record value and truncate records that do not meet the monotonically increasing condition.
Based on the index file, whether the picture group is normal or abnormal is determined based on whether or not a predetermined code is present at a predetermined position of the first pack constituting the picture group in the video file. Is deleted, and records that point to the picture group and later in the index file are also deleted.
Check whether the last picture group in the video file is composed of a multiple of a predetermined number of bytes, and if there is a remainder instead of a multiple of the predetermined number of bytes, the remainder is truncated,
Recording the index file and the video file;
And a video recording method. Processing for deleting meaningless data at the end of both the index file and the video file based on the presence of information indicating that recording is in progress and is recorded upon receipt of a recording start instruction and cleared upon receipt of a recording stop instruction Run the
The video recording method according to claim 3.

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