JP2004152359A - Data recorder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve continuous recording of data even when defective sectors are frequently detected from a disk-like recording medium such as an optical disk. <P>SOLUTION: The data recorder comprises an encoding means for compression-coding uncompressed digital data inputted thereto, recording buffer memory for temporarily storing the coded data outputted from the encoding means, a disk recording control means for recording the data outputted from the recording buffer memory, and the number of defective sectors monitoring means for monitoring the number of defective sectors in a unit time detected during the data recording operation, and when the count of the defective sectors in a unit time by the number of the defective sectors monitoring means is not less than a threshold, a bit rate of the compression-coding by the encoding means is reduced to continue the recording. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a data recording apparatus that compresses and encodes uncompressed digital video data and the like and then records the data on a disk-shaped recording medium.
[0002]
[Prior art]
Recently, various types of recordable optical discs have been circulating, and optical disc recording / reproducing apparatuses equipped with such recordable optical discs and having a function of recording and reproducing data on the optical discs are also used, for example, home DVD recorders and the like. It has been commercialized as.
[0003]
When recording, for example, moving image data on an optical disc, uncompressed digital data continuously input from a digital video / audio source is encoded by an encoding means (encoder) into an MPEG (Moving Picture Experts Group). In general, compression encoding is performed using a method, and the data amount is compressed and recorded. In this case, the encoded data continuously output from the encoding means is temporarily stored in the recording buffer memory once, and the data output from the recording buffer memory is recorded according to the disk recording format. After converting the data into data for use, the data is recorded on an optical disc.
[0004]
At this time, when there are few problematic sectors on the optical disc, the remaining amount of the recording buffer memory is secured, and continuous recording of video data is achieved. However, if there are many problematic sectors on the optical disc, the data is written several times in the same sector and the pass / fail judgment is made. If the write operation fails several times, a bad sector (defective sector) is obtained. Is determined, and data is written to the substitute sector. This operation must be performed frequently, which may lead to a situation in which the recording buffer memory overflows.
[0005]
[Problems to be solved by the invention]
As described above, when the recording buffer memory overflows, the buffer management breaks down, and it becomes impossible to store continuously input data in the recording buffer memory, and as a result, recording is temporarily interrupted. As a result, continuous recording of video data cannot be achieved.
[0006]
The present invention has been made in view of the above points, and an object of the present invention is to enable continuous recording of data even when a defective sector is frequently detected on a disk-shaped recording medium such as an optical disk. is there.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, a data recording device according to the present invention comprises:
Encoding means for compressing and encoding incoming uncompressed digital data, recording buffer memory for temporarily storing encoded data output from the encoding means, and data output from the recording buffer memory Disk recording control means for recording a disk-shaped recording medium, and a bad sector number monitoring means for monitoring the number of bad sectors per unit time detected during the data recording operation,
When the number of bad sectors counted per unit time by the bad sector number monitoring means is equal to or greater than a threshold value, the recording is continued by reducing the bit rate of the compression coding by the coding means. Or
Or
Encoding means for compressing and encoding incoming uncompressed digital data, recording buffer memory for temporarily storing encoded data output from the encoding means, and data output from the recording buffer memory Disk recording control means for recording a disk-shaped recording medium, and a memory remaining amount monitoring means for monitoring the remaining amount of the recording buffer memory,
If the memory remaining amount monitoring unit detects that the remaining amount of the recording buffer memory has become equal to or less than a threshold value, the encoding unit reduces the compression encoding bit rate and continues recording. And so on.
[0008]
By doing so, when a defective sector is frequently detected during the data recording operation, or when the remaining amount of the recording buffer memory is reduced due to the frequent detection of the defective sector, the compression encoding bit is used. By lowering the rate, the amount of data input to the recording buffer memory per unit time is reduced, and as a result, it is possible to avoid as much as possible that the recording buffer memory overflows and the buffer management is broken. Thus, although the bit rate is reduced (that is, the recording data is of low resolution), it is possible to guarantee continuous recording of data.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0010]
FIG. 1 is a block diagram schematically showing a main part of a data recording / reproducing apparatus according to a first embodiment of the present invention. This embodiment is an example of application to a home DVD recorder using an optical disk as a recording medium. is there.
[0011]
In FIG. 1, reference numeral 1 denotes a digital video / audio source that continuously outputs uncompressed digital video / audio data for recording (hereinafter, referred to as recording input data) to the apparatus of the present embodiment; An encoding unit for continuously compressing and encoding (quantizing and variable-length encoding) input data for recording using an encoding method, and generating and outputting encoded data; The recording buffer memory 4 for temporarily recording the encoded data to be recorded, converts the encoded data output from the recording buffer memory 3 into recording data conforming to the disc recording format, A disk recording / reproduction control unit for recording and reproducing data recorded on the optical disk 5, 5 is an optical disk composed of a recordable DVD, and 6 is a disk recording / reproduction control unit 4. In response to write report to exchange sector, counting the number of detected defective sectors per unit time, is a defective sector number monitoring unit for monitoring.
[0012]
In the configuration shown in FIG. 1, the defective sector number monitoring section 6 counts the number of defective sectors detected during the data recording operation, and constantly determines whether the number of detected defective sectors per unit time has exceeded a threshold value. If the number of bad detection sectors per unit time is less than the threshold value, the encoding unit 2 is instructed to perform relatively high-resolution compression encoding at a normal bit rate. When the number of defective sectors detected per unit time is equal to or larger than the threshold value, the encoding unit 2 is instructed to perform low-resolution compression encoding at a reduced bit rate. Also, if the number of badly detected sectors per unit time returns to below the threshold value during compression encoding at a reduced bit rate, the encoding unit 2 is given a normal bit rate. An instruction is issued to return to the relatively high resolution compression encoding process.
[0013]
FIG. 2 is a flowchart illustrating the flow of the process according to the present embodiment. In step S1, the encoding of the input data for recording by the encoding unit 2 is started. In step S2, the data read from the recording buffer memory 3 is recorded on the optical disk 5 by the disk recording / reproduction control unit 4. During this recording operation, the disk recording / reproduction control unit 4 constantly monitors whether or not a defective sector is detected in step S3. If a bad sector is detected, the process proceeds to step S4, and if not, the process proceeds to step S5. In step S4, the disk recording / reproduction control unit 4 reports a bad sector detection report to the bad sector number monitoring unit 6, and the bad sector number monitoring unit 6 counts the number of bad sectors. Proceed to.
[0014]
In step S5, the bad sector number monitoring unit 6 determines whether or not the number of detected bad sectors per unit time is equal to or greater than a threshold. If the number is equal to or greater than the threshold, the process proceeds to step S6. If not, the process proceeds to step S7. In step S6, the encoding unit 2 that has received the instruction from the bad sector number monitoring unit 6 switches to the control of the compression encoding in which the bit rate is reduced, and returns to step S2.
[0015]
In step S7, it is determined whether or not the bit rate of the current compression coding by the coding unit 2 is low resolution. If the bit rate is low and the resolution is low, the process proceeds to step S8. Returns to step S2. In step S8, it is determined whether or not the number of defective sectors detected per unit time is less than the threshold value. If it is less than the threshold value, the process proceeds to step S9; otherwise, the process returns to step S2. In step S9, the bit rate of the compression encoding performed by the encoding unit 2 is restored, and the process returns to step S2.
[0016]
As described above, in this embodiment, when a defective sector is frequently detected during the data recording operation, the bit rate of the compression encoding is reduced to reduce the data amount per unit time input to the recording buffer memory. Thus, it is possible to prevent the buffer memory for recording from overflowing and the buffer management from being broken. Therefore, although the bit rate is reduced (that is, the recording data has low resolution), continuous recording of the data can be guaranteed.
[0017]
FIG. 3 is a block diagram schematically showing a main part of a data recording / reproducing apparatus according to a second embodiment of the present invention. This embodiment is also an example of application to a home DVD recorder using an optical disc as a recording medium. is there. In FIG. 3, the same components as those in the first embodiment shown in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted to avoid duplication.
[0018]
In FIG. 3, reference numeral 7 denotes a memory remaining amount monitoring unit that monitors the remaining amount of the recording buffer memory 3. In the present embodiment, at the time of data recording operation, the memory remaining amount monitoring unit 7 constantly monitors the remaining amount of the recording buffer memory 3, and when the remaining memory amount exceeds the threshold value, the encoding unit 2 On the other hand, an instruction is issued to perform compression encoding at a relatively high resolution at a normal bit rate. Is instructed to perform low-resolution compression encoding in which is dropped. Also, when performing compression encoding at a reduced bit rate, if the remaining memory has returned to a state exceeding the threshold value, the encoding unit 2 is compared with the normal bit rate at a relatively low bit rate. Is instructed to return to the high-resolution compression encoding process.
[0019]
FIG. 4 is a flowchart illustrating the flow of the process according to the present embodiment. In step S11, encoding of the input data for recording by the encoding unit 2 is started, and in step S12, the data read from the recording buffer memory 3 is recorded on the optical disk 5 by the disk recording / reproduction control unit 4. During the recording operation, the remaining amount of the recording buffer memory 3 is always measured by the remaining memory amount monitoring unit 7 in step S13. Then, in step S14, the memory remaining amount monitoring unit 7 determines whether or not the remaining amount of the recording buffer memory 3 is equal to or smaller than the threshold value. If the remaining amount is equal to or smaller than the threshold value, the process proceeds to step S15. Otherwise, the process proceeds to step S16. In step S15, the encoding unit 2 which has received the instruction from the memory remaining amount monitoring unit 7 switches to the control of the compression encoding in which the bit rate is reduced, and returns to step S12.
[0020]
In step S16, it is determined whether or not the bit rate of the current compression coding by the coding unit 2 is low resolution. If the bit rate is low and the resolution is low, the process proceeds to step S17. Returns to step S12. In step S17, it is determined whether or not the remaining amount of the recording buffer memory 3 has exceeded a threshold value. If the remaining amount has exceeded the threshold value, the process proceeds to step S18. If not, the process returns to step S12. In step S18, the bit rate of the compression encoding performed by the encoding unit 2 is restored, and the process returns to step S12.
[0021]
As described above, according to the present embodiment, when the remaining capacity of the recording buffer memory is reduced due to frequent detection of a defective sector, the bit rate of the compression encoding is reduced to be input to the recording buffer memory. The amount of data per unit time is reduced, thereby preventing the buffer memory for recording from overflowing and the buffer management from being broken. Therefore, although the bit rate is reduced (that is, the recording data has low resolution), continuous recording of the data can be guaranteed.
[0022]
【The invention's effect】
As described above, according to the present invention, continuous recording of data can be maintained even when a defective sector is frequently detected on a disk-shaped recording medium such as an optical disk.
[Brief description of the drawings]
FIG. 1 is a block diagram schematically showing a main part of a data recording / reproducing apparatus according to a first embodiment of the present invention.
FIG. 2 is a flowchart illustrating a processing flow according to the first embodiment of the present invention.
FIG. 3 is a block diagram schematically showing a main part of a data recording / reproducing apparatus according to a second embodiment of the present invention.
FIG. 4 is a flowchart showing a flow of processing according to a second embodiment of the present invention.
[Explanation of symbols]
Reference Signs List 1 digital video / audio source 2 encoding unit 3 recording buffer memory 4 disk recording / reproduction control unit 5 optical disk 6 bad sector number monitoring unit 7 memory remaining amount monitoring unit

Claims (4)

Encoding means for compressing and encoding incoming uncompressed digital data, recording buffer memory for temporarily storing encoded data output from the encoding means, and data output from the recording buffer memory Disk recording control means for recording a disk-shaped recording medium, and a bad sector number monitoring means for monitoring the number of bad sectors per unit time detected during the data recording operation,
If the count of bad sectors per unit time by the bad sector count monitoring means is equal to or greater than a threshold value, the coding means reduces the compression encoding bit rate to continue recording. A data recording device characterized by the above-mentioned. In claim 1,
When the count number of bad sectors per unit time becomes less than the threshold value after the compression encoding bit rate is reduced, the compression encoding bit rate by the encoding unit is restored. A data recording device, characterized in that: Encoding means for compressing and encoding incoming uncompressed digital data, recording buffer memory for temporarily storing encoded data output from the encoding means, and data output from the recording buffer memory Disk recording control means for recording a disk-shaped recording medium, and a memory remaining amount monitoring means for monitoring the remaining amount of the recording buffer memory,
If the memory remaining amount monitoring unit detects that the remaining amount of the recording buffer memory has become equal to or less than a threshold value, the encoding unit reduces the compression encoding bit rate and continues recording. A data recording device characterized in that: In claim 3,
When the remaining amount of the recording buffer memory exceeds a threshold value after the compression encoding bit rate is reduced, the compression encoding bit rate of the encoding unit is returned to the original value. Characteristic data recording device.

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