JPH06349206A - Disc recording/reproducing method and apparatus - Google Patents

Abstract

PURPOSE:To enable the increase of a transfer rate at a time when a disc is used as storage media and the restructure of a damaged data on a disc medium without lowering the transfer rate in the recording and reproduction of the dynamic image of polyphase. CONSTITUTION:Recording reproducing discs 117-121, an error-block position storage circuit 123 holding the positional information of a recording block, in which an error is generated, a correction-data storage circuit 125 holding the correction data of said recording block, a scanning-block positional register 124 successively displaying the positions of recording blocks during scanning reproduction and an error-block rewrite control circuit 122 conducting recording on said recording block are provided. The error of the recording block in the disk is detected at the time of (m)-order sequential scanning reproduction, the correction data of the block is stored, and the correction data are recorded to said recording block at the time of (m+1)th order and subsequent sequential scanning reproduction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a band-compressed image,
The present invention relates to a method and apparatus for recording or reproducing voice or the like on a storage medium such as a magnetic disk or an optical disk, and particularly to a method and apparatus for realizing high-speed and highly reliable recording and reproduction.

[0002]

2. Description of the Related Art In recent years, rapid progress in compression technology (high-efficiency coding technology) of video signals and audio signals and progress of international standardization (MPEG, etc.), improvement of storage capacity of storage media and ISDN
2. Description of the Related Art With the widespread use of digital communication represented by, a database service of moving image information by a digital communication network has become feasible. With this moving image database service, request-type services and interactive services, which are difficult to achieve with conventional terrestrial broadcasting, satellite broadcasting, and other broadcast-type services, can be realized, so research and development is actively pursued. ing.

However, in the moving image information, one program is from several tens of seconds to several hours, and the storage medium is occupied for a long time during the service, so that it is shared by a plurality of users at the same time, and in addition, in real time for each request. In order to respond, multiple access technology is required as a recording / playback method for storage media. Therefore, in order to realize multiple access, moving image information such as a video signal is divided into a plurality of video blocks, cyclically rearranged in a predetermined format and recorded in a storage medium, and transmitted unique to the video signal. A method has been proposed in which a plurality of video signals having different temporal phases can be reproduced by cyclically scanning and reproducing at a transfer speed n times the speed (for example, Japanese Patent Application No. 5-9736).
No. "Recording and reproducing method", Japanese Patent Application No. 5-9738 "Recording and reproducing method").

The above recording / reproducing method will be briefly described below with reference to FIGS. 4, 5, and 6. FIG. 4 is a conceptual diagram of multiple access timing according to the recording / reproducing method.
4A shows an input video signal having a program length Tp, FIG. 4B shows a recording / playback signal on a storage medium, FIG. 4C is an access point, and FIG. 4D is an output video signal to a plurality of users. In this timing diagram, the number of video block divisions of the input video signal (a) is 11. FIG. 5 shows a recording / reproducing head for a storage medium (magnetic disk) according to the above recording / reproducing method.
It is a tracking operation figure of 501.

First, the recording operation on the storage medium will be described. A video signal composed of 11 video blocks is first divided into n (=
4) 1 / by block in a storage medium (for example, a magnetic disk device) capable of recording / reproducing at double transfer rate
High-speed recording is performed by compressing the time axis n times.

At this time, as shown in FIG. 5, the tracking of the recording / reproducing head of the magnetic disk device is basically moved sequentially to adjacent tracks for scanning, and the same recording disk is used at Tp / n cycle (access cycle). All the print data in the area are cyclically scanned (hereinafter, this operation is called sequential scanning). In the process of repeating this sequential scanning n times, the entire video signal is converted into a predetermined format and recorded.

Next, a method of reproducing a signal recorded in the above format will be described with reference to FIG.
By reproducing the blocks already recorded by the above-described recording operation at the speed of n times, and then sequentially cyclically scanning and reading, the recording / reproducing signal shown in FIG. 4B is obtained. Since this signal is reproduced at high speed at n times speed, Tp /
The head information (block indicated by "1" in the figure) of the video signal is read out in n cycles. Furthermore, since the video signal is read out in the above-mentioned unique format, by continuously extracting the video signal from the head information at a predetermined interval,
It is possible to obtain a plurality of video signals having different temporal phases shown in FIG.

FIG. 6 is a block diagram of a packet for multiplexing video blocks of a video signal. By multiplexing the video block identifier with the overhead of the packet at the time of recording, the video signal sequence of each phase can be extracted from the recording / reproducing signal by using this identifier at the time of reproducing.

By exchanging and distributing the video signals of a plurality of phases in accordance with the access timings of a plurality of users, multiple access can be realized in the access cycle Tp / n. Further, since the recorded data is reproduced by the above-mentioned sequential scanning,
It is possible to bring out the maximum transfer speed of magnetic disks,
The access cycle can be shortened as much as possible.

[0010]

However, when the above recording / reproducing method is realized by using a general magnetic disk, an optical disk or the like as a storage medium, there are the following problems.

First, the transfer rate is insufficient, and the access cycle Tp / n cannot be shortened sufficiently. The maximum transfer rate of a general magnetic disk is about 3 MByte / sec. For example, when recording and reproducing moving image information for 2 hours at a transmission rate of 1.5 Mbps, the access cycle becomes as long as about 8 minutes. Therefore,
The user will not be able to receive the video service without waiting for a maximum of about 8 minutes.

Next, in a general disk type recording / reproducing apparatus, access and recording / reproducing are controlled on the basis of a unit such as a sector. (Read out, replace the video block part you want to record, and record it again on the disc.)
Processing is required, and the transfer speed is reduced due to the processing.

Further, with a magnetic disk or the like, there is a high possibility that the recorded data will be damaged, so it is necessary to repair or reconstruct the data. However, with this recording / reproducing method,
In order to repair a local data error occurrence portion, it is impossible to move the recording / reproducing head to a damaged portion and rebuild it. This is because moving the recording / reproducing head to the damaged portion disrupts the reproduction operation by the above-described sequential scanning, and as a result, the transfer speed decreases and the image cannot be constantly transferred.

The present invention solves the above-mentioned conventional problems, and provides a highly reliable disk recording / reproducing method and apparatus for increasing the transfer rate of a recording / reproducing disk and preventing the transfer rate from being lowered due to error processing. The purpose is to do.

[0015]

In order to achieve this object, a disc recording / reproducing method of the present invention uses a plurality of recording / reproducing discs including a redundant recording / reproducing disc, and performs each recording at the time of m-th sequential scanning reproduction. An error in a recording block reproduced from the reproduction disc is detected (m is an integer of 1 or more), and the error is corrected by the position information of the recording block in which the error is detected and the position information and reproduction data from the plurality of discs. The corrected data of the recorded block thus obtained is temporarily stored, and the corrected data is recorded in the recorded block at the time of progressive scanning reproduction of the (m + 1) th and subsequent recording blocks according to the temporarily stored content.

Further, a disk recording / reproducing method is adopted in which a block of a time-series signal is multiplexed and recorded in a fixed-length packet completed by one or a plurality of recording blocks.

Further, in the disk recording / reproducing apparatus of the present invention, error block position storage means for holding the position information of the recording block in which an error has occurred, correction data storage means for holding the correction data of the recording block, and sequential scanning It has a configuration including a scanning block position register indicating the position of a recording block being reproduced and error block rewriting control means for recording the correction data read from the correction data storage means in the recording block. ing.

[0018]

According to this method and configuration, a plurality of recording / reproducing disks are simultaneously operated in parallel to increase the transfer speed, and at the same time, a plurality of recordings including error information from individual recording / reproducing disks and a redundant recording / reproducing disk. The data can be corrected by the reproduction data from the reproduction disc, and the reliability is improved.

Further, by storing the error block position and generating and storing the correction data, the correction data can be written in the damaged portion of the recorded contents while continuously performing the sequential scanning reproduction, so that the recorded contents are repaired. Transfer rate does not decrease.

Further, the video block is multiplexed into a packet of a predetermined length in consideration of the recording block and the sector length on the disk medium and the timing thereof, and is recorded at a predetermined timing. Therefore, access, recording / reproduction processing is performed. Is completed in recording block units, and the video signal can be efficiently recorded with a relatively simple circuit.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A disk recording / reproducing method and apparatus according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a disc recording / reproducing apparatus according to a disc recording / reproducing method in an embodiment of the present invention.

In FIG. 1, 100 is a packet division / synthesis circuit, 101 is an error processing circuit A, 102 to 106 are switch circuits, and 107 to 111 are error processing circuits B and 11.
2 to 116 are disk interfaces (I / F), 11
7 to 121 are magnetic disks, 122 is an error block rewriting control circuit, 123 is an error block position storage circuit,
Reference numeral 124 is a scan block position register, 125 is a corrected data storage circuit, and 126 is a parallel disk control circuit.

FIG. 2 is a signal processing timing chart by the disc recording / reproducing method of this embodiment, and FIG. 3 is a signal multiplexing configuration diagram by the disc recording / reproducing method of this embodiment. The operation of the disc recording / reproducing apparatus shown in FIG. 1 will be described below with reference to FIGS.

In FIG. 1, a recording / reproducing signal which is an input / output signal of the present apparatus is a time-series signal having a format capable of simultaneously reproducing video signals having a plurality of phases. This apparatus basically realizes the above-mentioned function by recording in the format described in the conventional technique or a format similar thereto to cyclically and sequentially scan and reproduce the recording medium.

At the time of recording a video signal on a magnetic disk, as shown in FIG. 6, a packet obtained by multiplexing a video block of an input video signal (hereinafter referred to as a recorded video signal) is sent to the packet division / synthesis circuit 100 at a specific phase interval. Is entered. At this time, as shown in FIG. 3A, the packet is a sector (FIG. 3) that is an access unit of the recording format on the magnetic disk medium of the magnetic disks 117 to 121.
In consideration of the data area length in (d), the length is fixed.

In the packet division / synthesis circuit 100,
As shown in FIG. 3A, the packet is divided into four layers # 1 to # 4 in the bit plane and the error processing circuit A101 is provided.
Supply to. In the error processing circuit A101, FIG.
As shown in (b), the parity is calculated from each of the data of # 1 to # 4 to generate the data of the parity layer #P.
The recorded video signals of the layers 1 to 4 and #P are supplied to the switch circuits 102 to 106, respectively. Switch circuit 10
2 to 106 are error processing circuits A when recording a video signal.
The output of each layer of 101 is directly input to the error processing circuit B107.
Connect to ~ 111. Error processing circuits B107-111
In the case of packet delimiters, # 1 to # 4 and #P
A CRC code is calculated and added to each layer as shown in FIG. 3C to generate a recording block having a length that is an integral multiple of the data area in the sector of FIG. 3D.

In the disk interfaces 112-116, each output D # of the error processing circuits B107-111
Recording processing (addition of ID section, addition of ECC, modulation, etc.) to a general magnetic disk is performed on 1 to 4 and D # P,
The data is recorded on the magnetic disks 117 to 121, respectively. At this time, since the length of the recording block is an integral multiple of the data area of the sector, the recording block is written at the timing when it is completed in a plurality of sectors as shown in FIG.

Next, the basic operation when reproducing a video signal from a magnetic disk will be described. As described above, the video signals recorded on the magnetic disks 117 to 121 are reproduced by sequential scanning according to the control signal from the parallel disk control circuit 126, and are reproduced as video signals from the disk interfaces 112 to 116 to the error processing circuits B107 to 111. Supplied. In the error processing circuits B107 to 111, an error is detected for each recording block based on the CRC added at the time of recording from the reproduced video signal, and together with the error detection result, the error processing circuit A101 is sent via the switch circuits 102 to 106. And the error detection result to the error block position storage circuit 123.

In the error processing circuit A101, according to the error detection result, correction data is corrected to the recording block of the magnetic disk in error by using the reproduction data from all the magnetic disks including the above-mentioned parity layer #P. It is generated and output to the correction data storage circuit 125. Further, the corrected reproduced video signals of the # 1 to # 4 layers are supplied to the packet division / combination circuit 100, and the reproduced video signals (recording / reproduction of FIGS. 1 and 2 are combined by combining the video packets of FIG. 3A). Output (included in the signal).

In the parallel disk control circuit 126,
A timing signal for sequential scanning and parallelization is supplied to each block based on control signals such as an R / W control signal, a sequential scanning timing signal, and an initialization signal which are supplied to the apparatus together with a recording video signal, Further, the disk interfaces 112 to 116 receive an R / W control signal for controlling the recording / reproducing operation on each magnetic disk, an access position control signal for specifying the access position of the magnetic disk, and an initialization signal for initializing the disk of the specified layer. Supply to. In the disk interfaces 112 to 116, the spindle motor and the recording / reproducing head position of the magnetic disk are controlled in accordance with the R / W control signal, the access position control signal, the initialization signal, etc. to perform the above-mentioned recording / reproducing operation and disk initialization. I do.

A method for recovering the contents of the recording block in which an error has been detected in the above process while maintaining the progressive scan reproducing operation will be described below with reference to FIGS. 1 and 2.

In the error block position storage circuit 123, the error detection results from the error processing circuits B107 to 111 (in the case of FIG. 2A, the recording blocks a and b of the # 4 layer in the m-th sequential scanning section are hatched). , c, d, e, f, g, h) and the information of the recording block position being accessed from the scanning block position register 124, the block position information in which an error has occurred is obtained as shown in FIG. Hold 4 places. The correction data storage circuit 125 stores the correction data supplied from the error processing circuit A101 shown in FIG. 2C under the control of the error block rewriting control circuit 122.

In the error block rewriting control circuit 122, the information of the recording block position being accessed from the scanning block position register 124 and the error block position information from the error block position storage circuit 123 are compared or calculated. It is determined that the position of the recording / reproducing head in the (m + 1) th sequential scanning section has reached the error block positions a, b, c, d. When the position of the recording / reproducing head reaches the error block position, the error block rewriting control circuit 1
According to the control from 22, the correction data of the corresponding block is read from the correction data storage circuit 125 at the timing shown in FIG. 2D, and the switch circuit 105 of the # 4 layer in which the error is detected, the error processing circuit B110, the disk The corrected data is written to the sectors corresponding to the recording blocks a, b, c, d of the magnetic disk 120 via the interface 115.

In the error blocks e, f, g, and h of FIG. 2A, an error is similarly detected during the (m + 1) th sequential scanning reproduction, and the recording blocks e, of the (m + 2) th sequential scanning section are detected. f,
It is repaired when g and h are accessed.

Next, a description will be given of the operation of reconstructing the recorded contents after the disk is exchanged due to the occurrence of a defective magnetic disk or the like. In this apparatus, the parallel disk control circuit 126 initializes the replaced new magnetic disk via the disk interface of the magnetic disk.
In this initialization process, the initialization operation is performed independently without performing the sequential scanning on the new magnetic disk. At this time, the remaining 4
The disc is sequentially scanned and reproduced to generate the corrected data of the layer of the new disc, and the reproduction of the video signal is continued. After the initialization is completed, the new magnetic disk reconstructs the entire contents of the magnetic disk by shifting to the sequential scanning operation according to the scanning of the recording / reproducing head of another disk and repeating the same operation as the error block repair operation. To go.

As described above, according to this embodiment, the time-series signals are used as video signals, and five magnetic disks including one redundant recording / reproducing disk are used as the recording / reproducing disks to simultaneously operate in parallel. It is possible to ensure a transfer rate four times as high as when using a single magnetic disk. Further, by adding a CRC code to each recording block of each magnetic disk and detecting an error, the error of the recording block can be corrected to reproduce the video signal and generate the corrected data.

Further, in addition to the error processing circuit B corresponding to the error detecting means and the error processing circuit A corresponding to the correction data generating means, an error block position storage circuit, a correction data storage circuit, and a block position for progressive scanning are shown. A scanning block position register and error block rewriting control circuit are provided, and block error detection, correction, and rewriting to the magnetic disk are performed over multiple sequential scanning cycles (access cycles), thereby performing reproduction by sequential scanning. The error data on the magnetic disk medium can be repaired while maintaining the operation.

Further, even when a magnetic disk that has suffered permanent damage is replaced by insertion / removal, it is possible to initialize a new magnetic disk and reconstruct the recorded contents while maintaining the sequential scanning / reproducing operation.

In this embodiment, the recording / reproducing signal is described as the recording video signal and the reproduction video signal are temporally multiplexed in the fixed-length packet format. However, these two signals are spatially separated. It can also be realized in different shapes.

In addition, the magnetic disk configuration is the redundant disk 1
Although the number of units including the number of units is 5, the number of units can be physically realized by various combinations including series operation in each layer.

In addition, for block error detection in each layer, a recording block is constructed by dividing a packet into CRs.
Although it is realized by adding C, the recording block may be divided by the data area length of the sector of each magnetic disk and the CRC may be added in that unit. Alternatively, the error detection result of the sector-by-sector ECC from the magnetic disk may be used. However, in the case of a new disk immediately after initialization by disk replacement, error information does not occur, so a signal for data reconstruction is separately provided. It is necessary to provide a line.

Further, although the packet is divided into the magnetic disks of each layer in the packet division / synthesis circuit 100 bit by bit, it may be divided in byte units or packet units.

[0043]

As described above, the present invention comprises a plurality of recording / reproducing disks including redundant recording / reproducing disks, error block position storage means, correction data generation storage means, scanning block position register and error block rewriting means. , An error of a recording block in the disc is detected at the time of the m-th sequential scanning reproduction, and is temporarily stored together with the correction data of the error-corrected recording block, and the sequential scanning of the (m + 1) th and subsequent recording blocks is performed. By recording the correction data in the recording block at the time of reproduction, it is possible to realize disk recording / reproduction having the following excellent features.

First, when a moving picture database system is realized, high-speed transfer is possible according to the degree of parallelism of recording / reproducing disks. Therefore, the access cycle in the above-mentioned video service is shortened and the video service with a short waiting time is provided. Can be realized.

Further, the reliability of the recording / reproducing disk, which is the most problematic factor in system construction, can be improved, and the recorded contents can be restored without interrupting the video service.

Further, by multiplexing the video block into a fixed-length packet in consideration of the recording block and the sector and recording the packet, the device can be realized with a relatively small-scale circuit and the recording / reproducing disk can be used efficiently. Because it's expensive
A low cost system can be constructed.

[Brief description of drawings]

FIG. 1 is a block diagram of a disk recording / reproducing apparatus according to an embodiment of the present invention.

FIG. 2 is a signal processing timing chart according to the disk recording / reproducing method in the embodiment of the present invention.

FIG. 3 is a signal multiplexing configuration diagram according to the disc recording / reproducing method of the present embodiment.

FIG. 4 is a conceptual diagram of multiple access timing according to a conventional recording / reproducing method.

FIG. 5 is a tracking operation diagram of a magnetic disk device according to a conventional recording / reproducing method.

FIG. 6 is a packet configuration diagram for multiplexing video blocks.

[Explanation of symbols]

 100 packet division synthesis circuit 101 error processing circuit A 102-106 switch circuit 107-111 error processing circuit B 112-116 disk interface 117-121 magnetic disk 122 error block rewrite control circuit 123 error block position storage circuit 124 scanning block position register 125 Corrected Data Storage Circuit 126 Parallel Disk Control Circuit

Claims (5)

[Claims] 1. A plurality of recording / reproducing discs including a redundant recording / reproducing disc are used, and the recorded contents of the plurality of recording / reproducing discs are cyclically sequentially scanned in parallel to simultaneously reproduce a plurality of time-series signals having different phases. A disk recording / reproducing method characterized by: 2. An error of a recording block reproduced from each recording / reproducing disk is detected at the time of the m-th sequential scanning reproduction (m is an integer of 1 or more), and position information of the recording block in which the error is detected, The correction data of the recording block that has been error-corrected using the position information and the reproduction data from the plurality of discs is temporarily stored, and the (m + 1) th and subsequent recording blocks of the (m + 1) th and subsequent recording blocks are stored according to the temporarily stored content. 2. The disc recording / reproducing method according to claim 1, wherein the correction data is recorded in the recording block at the time of progressive scanning reproduction. 3. A disc recording / reproducing method for cyclically sequentially scanning the recorded contents of a recording / reproducing disc to simultaneously reproduce a plurality of time-series signals having different phases, wherein one or a plurality of blocks of the time-series signal are used. Disc recording / reproducing method characterized by multiplexing and recording in a fixed-length packet completed by the recording block and sector. 4. A fixed length packet is divided into a plurality of discs including the redundant recording / reproducing disc and recorded, and an error detection code is multiplexed in each of the divided packets. The described disk recording / playback method. 5. A disc recording / reproducing apparatus comprising a plurality of recording / reproducing discs including a redundant recording / reproducing disc, comprising: error detecting means for detecting an error in reproduction data of each recording / reproducing disc; and a recording block in which an error has occurred. Error block position storage means for holding position information of the recording block, correction data generation means for generating correction data of the recording block by output from the plurality of recording / reproducing disks, and correction data storage for holding correction data of the recording block. Means, a scanning block position register indicating the position of a recording block during sequential scanning reproduction, correction data read from the correction data storage means, output of the scanning block position register and error block position storage means. A disk provided with an error block rewriting control means for recording according to the output Recording and reproducing apparatus.