JP2008199077A - Video recording/reproducing method and device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To distribute increase of system load during transition to other file when digital video data is recorded/reproduced for a plurality of files. <P>SOLUTION: In order to distribute the system load increasing locally in the transition operation to other file when recording is performed for a long time at high bit rate and the maximum file size is exceeded, opening of the file, closing of a file which is the writing destination of a previous digital video signal after transition to the opened file and alteration of the writing destination file of the digital video signal are controlled based on the maximum file size and the data size of a digital video signal written in the file. The next file is opened at a timing sufficiently before the maximum file size is exceeded, and the file used until now is closed at a timing with sufficient time to spare after transition to the next file. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a video recording / reproducing method and apparatus that can realize a transition to another file when recording a video at a high bit rate with high reliability.

A hard disk video recorder is an apparatus that converts an input video signal into compressed digital video data and records it in a hard disk drive (hereinafter referred to as HDD), or reproduces a compressed digital video signal recorded in the HDD.
FIG. 6 is a functional block diagram showing a conventional hard disk video recorder.
The hard disk video recorder includes a video signal input block 51, a video synchronization circuit 52, a stream encoder 53, a system controller 54, a file system 55, a hard disk drive 56, a stream decoder 57, and a video signal output block 58.

The video signal input block 51 is a circuit block for inputting a video signal.
The video synchronization circuit 52 is a circuit that synchronizes an input video signal and generates various signals including a vertical synchronization signal, a horizontal synchronization signal, and a clock signal necessary in the subsequent stage.
The stream encoder 53 is a circuit that performs codec on the input video signal and compresses the video signal.
The system controller 54 controls each part including the stream encoder 53, the stream decoder 57, and the video synchronization circuit 52.
The file system 55 performs file management when the hard disk drive 56 is under management and digital video data compressed for each fixed data size is recorded as different files.
The hard disk drive 56 records the compressed digital video data on the hard disk.
The stream decoder 57 is a circuit that decompresses the codec compression of the data read from the hard disk drive 56 and reconstructed into the original compressed video data before division.
The video signal output block 58 is a circuit block that adds a synchronization signal or the like to the video signal that has been decompressed by codec compression and outputs the same waveform as the video signal input to the system.

Next, the operation will be described.
When recording a video signal, the video signal is input to the video signal input block 51. Furthermore, in the video synchronization circuit 52, various signals including a vertical synchronization signal, a horizontal synchronization signal, and a clock signal necessary for the next block are generated by synchronizing with the video signal input to the video signal input block 51.
The next stream encoder 53 performs codec on the input video signal to compress the video signal.
The digital video data compressed by the stream encoder 53 is recorded on the hard disk drive 56.

When reproducing the video signal, the digital video data is read out from the hard disk drive 56 and taken out.
The extracted data is decompressed by the stream decoder 57 and sent to the next block.
The video signal output block 58 adds the synchronization signal generated in the video synchronization circuit 52 to the decompressed video signal and outputs the same waveform as the video signal input to the system.

By the way, in order to realize the above functions, such a hard disk video recorder needs to control the HDD as a storage device, and generally uses an OS (operating system) as its control system.
The OS controls the file system 55 under the management, and controls the file data when recording / reproducing the digital video data to / from the HDD 56.
Under the management of the OS in such a hard disk video recorder or the like, file management is generally performed to manage the recording byte amount of data when writing a file to the HDD or reading a file from the HDD.
Specifically, in the case of a 32-bit system, assuming that a 32-bit signed integer is used to manage the number of recorded bytes, the file data is substantially 31 bits and a value of 2 to the 31st power. To represent the number of bytes, one maximum file size is limited to 2 GB.
Under such system conditions, the video signal handled by the hard disk video recorder is changed from the standard image quality to the high image quality, the screen resolution is changed from the standard to HD (High Definition High Definition), the frame rate is changed from the standard to the high frame rate, etc. As a result, the amount of data per unit time recorded on the HDD increases, and when recording is performed for a long time, the maximum file size exceeds 2 GB. This will hinder data recording to the HDD.
Therefore, generally, when the recording file size is likely to exceed the maximum file size of the system, it is necessary to move to another file, and information is divided and stored in a plurality of files.

FIG. 7 is a flowchart showing the file recording operation in the conventional hard disk video recorder. FIG. 8 is a flowchart showing the execution timing of each process in the file recording of the conventional hard disk video recorder in order on the time axis.
The outline of conventional file recording operation will be described below with reference to FIGS.
As shown in the flowchart of FIG. 7, the hard disk video recorder basically writes the captured digital video data to the HDD drive for each frame size or specific size.
This operation is repeatedly looped (step S105, step S106, step S107).
During this loop, it is checked whether the size of the file being recorded exceeds the maximum file size (for example, 2 GB) (step S107), and before exceeding, the process moves to another file (step S111 to step S115).
As the file migration, a migration operation is performed in which the file currently being written is closed (step S111), the file to be migrated next is opened (step S112), and the file to be actually written is switched (step S113).
FIG. 8 shows the operation represented by the flowchart of FIG. 7 on the time axis.
In FIG. 8, for example, the interval between the process of step S104 and the process of step S111 indicates the time between the timing at which the process at step S104 is executed and the timing at which the process at step S111 is executed.
In addition, each process of step S111, step S112, and step S113 is shown as a process that is continuously executed, and this is performed before the file size to be recorded exceeds the maximum file size (for example, 2 GB). Shows that the migration of the file is performed, but at this time the currently written file is closed, then the file to be migrated is opened, and the migration operation of switching the actual file to be written is performed centrally. Yes.
Although the recording operation has been described above, the same applies to the reproduction operation.
Examples of recording arbitrary information by making a divided file include a recording / reproducing apparatus and an information recording method for recording arbitrary information to form a divided file (see Patent Document 1).
JP 2002-140886 A

  Therefore, in the conventional hard disk video recorder, when the recording file size is likely to exceed the maximum file size of the system, the system intensively performs the operation of moving to another file, so the load on the system increases rapidly, There was a problem that data recording to the HDD was hindered.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a video recording / reproducing method and apparatus capable of distributing an increase in the load on the system when shifting to another file.

  In order to achieve the above object, a video recording method of the present invention is a video recording method for accessing a hard disk drive and recording a digital video signal for a plurality of files in the hard disk drive, wherein the maximum file size of the file and And controlling the opening and closing of the file and the change of the file to which the digital video signal is written based on the data size of the digital video signal written to the file. .

  In order to achieve the above object, a video playback method of the present invention is a video playback method for accessing a hard disk drive and reading out and playing back digital video signals recorded in a plurality of files on the hard disk drive. And controlling the opening and closing of the file and the change of the file to which the digital video signal is read based on the file size and the data size of the digital video signal read from the file. It is characterized by.

  In order to achieve the above object, a video recording method of the present invention is a video recording method for accessing a hard disk drive and recording digital video signals for a plurality of files in the hard disk drive. A step of opening a file, writing a digital video signal to the opened file, and when a data size of the digital video signal written to the file reaches a maximum file size of the file, a file to which the digital video signal is written is A step of changing, and a step of closing all the files after completion of the recording.

  In order to achieve the above object, a video playback method of the present invention is a video playback method for accessing a hard disk drive and reading out and playing back digital video signals recorded in a plurality of files on the hard disk drive, before starting playback. A step of opening all files, and reading a digital video signal recorded from the opened file, and when the data size of the digital video signal read from the file reaches the maximum file size of the file, the digital video signal A read destination file and a step of closing all the files after the end of the reproduction.

  In order to achieve the above object, a video recording apparatus of the present invention is a video recording apparatus that accesses a hard disk drive and records a digital video signal for a plurality of files in the hard disk drive, the file managing the hard disk drive Control the file system and the file system, open the file based on the maximum file size of the file and the data size of the digital video signal written to the file, and the previous digital And a controller for controlling closing of the file to which the video signal is written and changing the file to which the digital video signal is written.

  In order to achieve the above object, a video playback apparatus according to the present invention is a video playback apparatus that accesses a hard disk drive and reads out and plays back digital video signals recorded in a plurality of files of the hard disk drive. A file system that manages the file system, the file system is controlled, the file is opened based on the maximum file size of the file and the data size of the digital video signal read from the file, and the opened file And a controller for controlling the closing of the file from which the previous digital video signal was read after the transfer and the change of the file from which the digital video signal was read.

  In order to achieve the above object, a video recording apparatus of the present invention is a video recording apparatus that accesses a hard disk drive and records a digital video signal for a plurality of files in the hard disk drive, the file managing the hard disk drive The system and the file system are controlled, all files are opened before the start of recording, and during recording, a digital video signal is written to the opened file, and the data size of the digital video signal written to the file And a controller that changes the file to which the digital video signal is written when the maximum file size of the file is reached, and closes all the files after the end of the recording.

  In order to achieve the above object, a video playback apparatus according to the present invention is a video playback apparatus that accesses a hard disk drive and reads out and plays back digital video signals recorded in a plurality of files of the hard disk drive. A file system that manages the file system, the file system is controlled, all files are opened before the start of reproduction, and during reproduction, a digital video signal is read from the opened file, and the digital video signal read from the file is read And a controller that changes the file from which the digital video signal is read when the data size reaches the maximum file size of the file and closes all the files after the end of the reproduction.

  According to such a video recording / playback method and apparatus of the present invention, an increase in system load accompanying the execution of the migration process to another file can be distributed, so that the process of migrating to another file with high reliability can be realized. is there.

(First embodiment)
Next, a video recording / reproducing method and apparatus according to the first embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a functional block diagram of a hard disk video recorder to which the video recording / playback method according to the first embodiment is applied.
This hard disk video recorder includes a video signal input block 1, a video synchronization circuit 2, a stream encoder 3, a system controller 4, a file system 5, a hard disk drive 6, a stream decoder 7, and a video signal output block 8.

The video signal input block 1 is a circuit block for inputting a video signal.
The video synchronization circuit 2 is a circuit that synchronizes an input video signal and generates various signals including a vertical synchronization signal, a horizontal synchronization signal, and a clock signal necessary in the subsequent stage.
The stream encoder 3 is a circuit that performs codec on an input video signal and compresses the video signal.
The system controller 4 controls each part including the stream encoder 3, the file system 5, the stream decoder 7, and the video synchronization circuit 2.
The file system 5 performs file management when the hard disk drive 6 is under management and digital video data compressed for each fixed data size is recorded as different files.
The hard disk drive 6 records the compressed digital video data on the hard disk.
The stream decoder 7 is a circuit that decompresses the codec compression of the data read from the hard disk drive 6 and reconstructed into the original compressed video data before division.
The video signal output block 8 is a circuit block that adds a synchronization signal or the like to the video signal decompressed by the codec compression and outputs the same waveform as the video signal input to the system.

Next, the operation will be described.
In the hard disk video recorder of the present embodiment, the system controller 4 controls the file system 5.
Then, when recording at a high bit rate for a long time and exceeding the maximum file size, the maximum file size of the file and the file are distributed so as to distribute the system load that locally increases in the operation of moving to another file. Based on the data size of the digital video signal written to the file, the file is opened, the file to which the previous digital video signal was written after the opened file is transferred, and the digital video signal is written. Control previous file changes.
As a result, the next file is opened at a timing sufficiently before the maximum file size (for example, 2 GB) is exceeded, and the file that has been used so far is closed at a timing with sufficient margin after the next file migration. .

FIG. 2 is a flowchart showing the file recording operation in the video recording / reproducing method of the present embodiment.
Steps S1, S2, S3, and S4 are initial setting processes for this file recording. In step S1, the maximum file size FS is set to MaxFS, and in the next step S2, the initial value of the file size FS is set to “0”. In step S3, the file number M is set to "1". In the subsequent step S4, the file with file number 1 is opened.
In the file recording, the captured digital video data is written into the HDD drive for each frame size or specific size (step S5), and the written digital video data size (capture data size) is set as the current file size FS value ( Steps S6), S7, S8, and S9 are repeatedly looped through the determination process.
As an example, during this loop, it is checked whether the file size being recorded exceeds the maximum file size (for example, 2 GB) (step S7). In addition, the timing when the file size becomes 1/3 of the maximum file size (step S9). ) And the timing when the maximum file size is 2/3 (step S8).
In these three steps S7, S8, and S9, the process of shifting to another file when the maximum file size is exceeded is performed in a distributed manner.

That is, when the value of the current file size FS, which is the size of the written digital video data (capture data size), is 1/3 of the maximum file size (2 GB), in step S9, the file immediately before the file currently in use Is executed (step S15, step S16).
When the current file size FS is 2/3 of the maximum file size (2 GB), the file to be used next to the currently used file is opened (step S14).
Also, before the current file size FS value exceeds the maximum file size (2 GB), that is, in this flowchart, the current file size FS value, which is the written digital video data size (capture data size), reaches the maximum file size. When this happens, a process of shifting from the currently used file to the next file is executed (step S11, step S12, step S13).

FIG. 3 is a flowchart showing the execution timing of each process in the flowchart shown in FIG. 2 in order on the time axis.
In FIG. 3, for example, the interval between the process of step S4 and the process of step S14 indicates the time from when the process of step S4 is completed until the process of the next step S14 is started.
Therefore, as compared with the conventional case shown in FIG. 8, it can be seen that the operations by the system on the time axis are distributed without being concentrated as shown in FIG. 3, and the load on the system is averaged.
That is, in the conventional case shown in FIG. 8, since the processing of step S111, step S112, and step S113 is executed continuously, the processing of step S111, step S112, and step S113 is continuously occurring. Since the system is completely involved in the processing of step S111, step S112, and step S113, the system load increases including the capture data writing process and the execution of the related process.
On the other hand, in the present embodiment, as shown in FIG. 3, the timing at which the processes of step S4, step S14, step S11, and step S16 are executed is continuously generated. In addition, the system operations on the time axis are distributed without being concentrated, and the load on the system is averaged.
The above description is for recording, but the same applies for reproduction.

  As described above, according to the first embodiment, writing to the write file for the maximum file size is performed based on the current amount of data written to the write file and the maximum file size of the write file. The ratio of the amount of data is determined based on preset criteria, and the next write file is opened when the current amount of data written to the write file reaches the criteria. And the operation of closing a file that has already been written is controlled so that the current amount of data written to the write file can be determined by appropriately selecting the determination criterion. The concentration of the timing to reach the standard can be avoided, and the process of closing and opening the file is distributed. It is possible, there is an effect that it is possible to average the load to the system.

In addition, when recording at a high bit rate with a hard disk video recorder for a long time, if the maximum file size is exceeded, the local system load can be distributed in the operation to move to another file, There is an effect that the delay in the recording operation is prevented and the reliability of continuous recording and recording / reproducing is improved.
Further, since the system load is distributed, it is not necessary to secure a processing speed corresponding to a locally increasing load, and there is an effect that the cost of the system can be reduced and the power consumption can be suppressed.
In addition, since the system load is distributed, there is no need to secure a processing speed corresponding to a locally increasing load, and the system design is facilitated with respect to the file migration operation.
In addition, although the timing of the file migration operation is limited, there is a degree of freedom in opening and closing the file, which has the effect of increasing the flexibility of the system.

(Second Embodiment)
Next, a second embodiment will be described.
The configuration of the hard disk video recorder to which the video recording / reproducing method of the second embodiment is applied is the same as that of the hard disk video recorder described in the first embodiment shown in FIG.
In the second embodiment, in order to distribute the locally increasing system load, all files are opened together before recording and reproduction, and all files are closed together after recording and reproduction.
FIG. 4 is a flowchart showing the file recording operation in the video recording / reproducing method according to the second embodiment.
FIG. 5 is a flowchart showing the execution timing of each process in the flowchart shown in FIG. 4 in order on the time axis.
In FIG. 5, for example, the interval between the process of step S25 and the process of step S31 indicates the time from when the process of step S25 is completed until the process of the next step S31 is started.

The file recording operation will be described below with reference to the flowchart shown in FIG.
Steps S21, S22, S23, and S24 are initial setting processes for this file recording. In step S21, the maximum value of the file number M is set to MaxM, and in the subsequent step S22, the maximum file size FS is set to MaxFS. In step S23, the initial value of the file size FS is set to “0”, and in step S24, the file number M is set to “1”.

In the second embodiment, a plurality of files (for example, file numbers 1 to MaxM) having a maximum file size (for example, 2 GB) are recorded before the captured digital video data is written to the HDD for each frame size or specific size. File)) and is opened in advance (step S25).
Then, the captured digital video data is written from the file of file number 1 to the HDD for each frame size or specific size (step S27), and the digital video data size (capture data size) written so far is set to the file size FS. (Step S28), it is determined whether or not the file size FS has reached the maximum file size MaxFS (step S29).
Then, the processing operations of step S26, step S27, step S28, and step S29 are repeatedly looped.
In this loop, it is checked whether or not the file size being recorded exceeds the maximum file size (2 GB), and when the maximum file size (2 GB) is reached (step S29), the file with the file number M currently in use is checked. Is executed to move to the next file with the file number M + 1 (step S31, step S32, step S33).
Then, when there is no data to be captured during the loop operation, the operations for closing all the files are performed together (step S41).

When the operation shown in the flowchart of FIG. 4 is performed, as shown in FIG. 5, the file open and close operations are concentrated at the beginning and end of a series of processing, but operations on the time axis at the time of capture are performed. Concentration of can be avoided.
Although the above description has been made on the operation during recording, the same applies during reproduction.

As described above, according to the second embodiment, when a high bit rate recording is performed for a long time with a hard disk video recorder, the file is transferred to another file when the maximum file size is exceeded. In this operation, the local system load can be distributed, the occurrence of a delay in the recording operation can be prevented, and the reliability of continuous recording and recording / reproducing can be improved.
Further, since the system load is distributed, it is not necessary to secure a processing speed corresponding to a locally increasing load, and there is an effect that the cost of the system can be reduced and the power consumption can be suppressed.
In addition, since the system load is distributed, there is no need to secure a processing speed corresponding to a locally increasing load, and the system design is facilitated with respect to the file migration operation.

It is a functional block diagram of the hard disk video recorder which implement | achieves the video recording / reproducing method by the 1st Embodiment of this invention. It is a flowchart which shows the operation | movement of file recording in the video recording / reproducing method of the 1st Embodiment of this invention. 3 is a flowchart showing the execution timing of each process in order on the time axis in the video recording / reproducing method according to the first embodiment of the present invention. It is a flowchart which shows the operation | movement of file recording in the video recording / reproducing method of the 2nd Embodiment of this invention. It is the flowchart which showed in order on the time-axis the execution timing of each process in the video recording / reproducing method of the 2nd Embodiment of this invention. It is a functional block diagram which shows the conventional hard disk video recorder. It is a flowchart which shows the operation | movement of file recording in the conventional hard disk video recorder. It is the flowchart which showed in order on the time axis the execution timing of each process in the file recording of the conventional hard disk video recorder.

Explanation of symbols

  4 ... system controller (controller), 5 ... file system, 6 ... hard disk drive.

Claims (12)

A video recording method for accessing a hard disk drive and recording digital video signals for a plurality of files in the hard disk drive,
Controlling the opening and closing of the file and the file change of the writing destination of the digital video signal based on the maximum file size of the file and the data size of the digital video signal written to the file;
A video recording method comprising:   The step of controlling the opening and closing of the file and the change of the file to which the digital video signal is written is based on the ratio of the data size of the digital video signal written to the file to the maximum file size of the file. The video recording method according to claim 1, further comprising: controlling opening, closing, and changing of the file.   The step of controlling the opening and closing of the file and the change of the file to which the digital video signal is written is based on the ratio of the data size of the digital video signal written to the file to the maximum file size of the file. Controls the opening of the file to which the next digital video signal is written, the closing of the file to which the previous digital video signal was written after shifting to the opened file, and the change of the file to which the digital video signal is written The video recording method according to claim 1, wherein: A video playback method for accessing a hard disk drive, reading out and playing back digital video signals recorded in a plurality of files of the hard disk drive,
Controlling the opening and closing of the file and the file change of the reading destination of the digital video signal based on the maximum file size of the file and the data size of the digital video signal read from the file; ,
A video playback method comprising:   The step of controlling the opening and closing of the file and the change of the file to which the digital video signal is read is based on the ratio of the data size of the digital video signal read from the file to the maximum file size of the file. 5. The video playback method according to claim 4, further comprising controlling the opening and closing of the file and the file change.   The step of controlling the opening and closing of the file and the change of the file to which the digital video signal is read is based on the ratio of the data size of the digital video signal read from the file to the maximum file size of the file. In addition, the file that is the next reading destination of the digital video signal is opened, the file that was the reading destination of the previous digital video signal after the open file is transferred, and the file that is the reading destination of the digital video signal is changed. 5. The video playback method according to claim 4, wherein control is performed. A video recording method for accessing a hard disk drive and recording digital video signals for a plurality of files in the hard disk drive,
Opening all files before recording begins;
Writing a digital video signal to the opened file, and changing a file to which the digital video signal is written when a data size of the digital video signal written to the file reaches a maximum file size of the file;
Closing all the files after the recording ends;
A video recording method comprising: A video playback method for accessing a hard disk drive and reading and playing back digital video signals recorded in a plurality of files of the hard disk drive,
Opening all files before playback begins,
Reading a digital video signal recorded from the opened file, and changing a file to which the digital video signal is read when the data size of the digital video signal read from the file reaches the maximum file size of the file; ,
Closing all the files after the end of playback;
A video playback method comprising: A video recording apparatus for accessing a hard disk drive and recording digital video signals for a plurality of files in the hard disk drive,
A file system for managing the hard disk drive;
The file system is controlled, and based on the maximum file size of the file and the data size of the digital video signal written to the file, the file is opened and the previous digital video signal after the opened file is transferred A controller for controlling the closing of the file to be written to and changing the file to which the digital video signal is written;
A video recording apparatus comprising: A video playback device that accesses a hard disk drive and reads and plays back digital video signals recorded in a plurality of files of the hard disk drive,
A file system for managing the hard disk drive;
The previous digital video signal after controlling the file system and opening the file and transferring the opened file based on the maximum file size of the file and the data size of the digital video signal read from the file A controller for controlling the closing of the file from which the file was read and the change of the file to which the digital video signal is read;
A video playback apparatus comprising: A video recording apparatus for accessing a hard disk drive and recording digital video signals for a plurality of files in the hard disk drive,
A file system for managing the hard disk drive;
The file system is controlled and all files are opened before recording is started. During recording, a digital video signal is written to the opened file, and the data size of the digital video signal written to the file is the file size. When the maximum file size is reached, the file to which the digital video signal is written is changed, and the controller closes all the files after the recording ends.
A video recording apparatus comprising: A video playback device that accesses a hard disk drive and reads and plays back digital video signals recorded in a plurality of files of the hard disk drive,
A file system for managing the hard disk drive;
The file system is controlled, all files are opened before the start of reproduction. During reproduction, a digital video signal is read from the opened file, and the data size of the digital video signal read from the file is the file size of the file. A controller that changes a file to which the digital video signal is read when the maximum file size is reached, and closes all the files after the end of the reproduction;
A video playback apparatus comprising:

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