JPH0738854A - Method and device for disk recording and reproduction - Google Patents

Abstract

PURPOSE:To obtain the method and device for recording or reproducing digital data at a high speed with high reliability by connecting plural recording and reproduction disks. CONSTITUTION:Data to be recorded are divided into plural recording blocks by a packet dividing and composing circuit 100 and an error processing circuit A101 calculates parity to generate data on a parity layer. An error processing circuit B104 calculates and adds CRC codes to the respective recording blocks after the parity process and outputs them, and they are passed through a disk I/F bus 108, and compressing and expanding circuits 109-112 and recorded on the magnetic disks 113-116. The data on the parity layer after being outputted to the error processing circuit A101 are inputted to an error processing circuit B105, which calculates and adds CRC codes the respective packets, so that the data on the parity layer which are outputted from the error processing circuit B105 are recorded on a magnetic disk 117.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk recording / reproducing method and a disk recording / reproducing apparatus for recording or reproducing digital data on a storage medium such as a magnetic disk or an optical disk at high speed and with high reliability.

[0002]

2. Description of the Related Art In recent years, it has become feasible to construct a database of moving images due to rapid progress in compression technology of video signals and audio signals as seen in MPEG and improvement in storage capacity of storage media.

Further, from the spread of ISDN and the research of broadband ISDN, research is actively conducted toward the realization of an interactive moving image database service using a digital communication network.

However, since the moving image information is from several tens of seconds to several hours per program, if it is serviced in real time, the database will be occupied for a long time. Therefore, in order to enable multiple users to access the database at the same time and respond to each user's request in real time, multiple access technology to the database is required.

Therefore, Japanese Patent Application No. 5-9736 “Recording / Reproducing Method” and Japanese Patent Application No. 5-9738 “Recording / Reproducing Method” have been proposed as conventional recording / reproducing methods for realizing multiple access.

FIG. 5 shows a conventional recording / reproducing method. First, the recording operation on the storage medium will be described. As shown in FIG. 5A, the video signal of the show time Tp is divided into 11 video blocks, and each of the 11 divided video blocks has an interval shown by a hatched portion in FIG. 5B. Then, high-speed recording is performed on a storage medium such as a magnetic disk at a transfer speed n (= 4) times.

At this time, the head of the magnetic disk drive basically moves continuously from the inside to the outside of the recording disk, as shown in FIG. 6, and the entire recording disk is driven at Tp / n cycle (access cycle). Scanning of print data is completed (hereinafter, this operation is called sequential scanning). By repeating this sequential scanning n times, the entire video signal is converted into a predetermined format and recorded.

Next, the reproducing operation from the storage medium will be described. The recording / reproducing signal shown in FIG. 5B is obtained by sequentially scanning the recording disk and reproducing at a speed of n times. Therefore, the video signal shown in φ1 of FIG. 5 (d) can be reproduced by continuously extracting the video blocks in the shaded area at intervals of n from the top information (blocks shown by “1” in the figure). Further, since the head information (block indicated by "1" in the figure) of the video signal is read at the Tp / n cycle, it is possible to obtain a plurality of video signals having different temporal phases.

FIG. 7 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 during recording,
During reproduction, this identifier can be used to extract the video signal sequence of each phase from the recording / reproducing signal.

[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 / s. 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 cannot receive the video service without waiting for a maximum of about 8 minutes.

Next, in a magnetic disk or the like, since there is a high possibility that the recorded data will be damaged, it is necessary to repair and reconstruct the data. However, in this recording / reproducing method, it is impossible to move the recording / reproducing head to a damaged portion and reconstruct it in order to repair a portion where a local data error occurs. This is because moving the recording / reproducing head to the damaged portion disrupts the reproduction operation by the above-described sequential operation, and as a result, the transfer speed decreases and it becomes impossible to constantly transfer the image.

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 decreasing due to error processing. The purpose is to do.

[0014]

In order to achieve this object, a disc recording / reproducing apparatus of the present invention records a video signal, and a packet division / combination circuit for dividing and combining a packet in which a video signal is multiplexed. Magnetic disk,
An error processing circuit A for calculating parity from video information to generate parity data, a correction data storage circuit for holding correction data of the video signal, and the error processing circuit A.
And a switch circuit for switching the output of the correction data storage circuit, an error processing circuit B for calculating a CRC code, an error block position storage circuit for holding the position information of the video signal in which an error has occurred, and an image during progressive scanning reproduction. A scanning block position register indicating the position of a signal, an error block rewriting control circuit for recording the correction data read from the correction data storage circuit, a disk interface for performing a recording process on the magnetic disk, and the error block A rewrite control circuit, a disk control circuit for controlling the scanning block position register and the disk interface, and a compression / expansion circuit for adjusting the transmission speed when recording and reproducing the video signal from the magnetic disk are provided. Have a configuration.

[0015]

According to the present invention, with the above-described structure, a plurality of recording / reproducing disks are simultaneously operated to increase the transfer rate, and a plurality of recording / reproducing disks including error information from each recording / reproducing disk and a redundant recording / reproducing disk are provided. The data can be corrected by the reproduction data from the 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 content while continuously performing the sequential scanning reproduction. Transfer rate does not decrease.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing the configuration of a disc recording / reproducing apparatus which realizes a disc recording / reproducing method according to 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 103 are switch circuits, and 104 to 105 are error processing circuits B and 10.
6 to 107 are disk I / Fs, 108 is a disk interface bus (hereinafter referred to as disk I / F bus), 1
09 to 112 are compression / expansion circuits, 113 to 117 are magnetic disks, 118 is a correction data storage circuit, 119 is an error block position storage circuit, 120 is an error block rewriting control circuit, 121 is a scan block position register, and 122.
Is a disk control circuit.

FIG. 2 is a signal processing timing chart according to the disc recording / reproducing method of the present embodiment, FIG. 3 is a signal multiplexing configuration diagram according to the disc recording / reproducing method of the present embodiment, and FIG. 4 is an internal configuration diagram of the compression / expansion circuit. . The operation of the disc recording / reproducing apparatus shown in FIG. 1 will be described below with reference to FIGS. 2, 3, and 4.

The disk recording / reproducing apparatus of the present embodiment basically records in the format described in the prior art or a format similar thereto to cyclically scan and reproduce the recording medium to realize the above function. It is a thing.

At the time of recording a video signal on a magnetic disk, as shown in FIG. 7, a packet in which a video block of an input video signal (hereinafter referred to as a recorded video signal) is multiplexed is divided into packets at a specific phase interval to synthesize a packet. Is input to. At this time, as shown in FIG. 3A, the packet has a fixed length in consideration of the data area length of the sector which is the access unit of the recording format of the magnetic disks 113 to 116.

In the packet division / synthesis circuit 100,
In order to record on the magnetic disks 113 to 116, the packet is divided into four equal parts # 1 to # 4 and supplied to the error processing circuit A101 as shown in FIG. In the error processing circuit A101, as shown in FIG. 3B, the parity is calculated from each data of # 1 to # 4 to generate the data of the parity layer #P, and the data of the parity layers # 1 to # 4 and #P are generated. The recording video signal of each layer is supplied to the switch circuits 102 to 103. The switch circuits 102 to 103 connect the output of the error processing circuit A 101 to the error processing circuits B 104 to 105 as they are when recording a video signal.

In the error processing circuits B104 to 105, the layers # 1 to # 4 and #P are shown in FIG.
2), (c-1), (d-1), (e-1), (f-
The CRC code is calculated and added as shown in 1), and
(B-3), (c-2), (d-2), (e-2),
A recording block having a length that is an integral multiple of the data area in the sector of (f-2) is generated.

In the disk I / Fs 106 to 107,
Outputs D # 1 to D # of the error processing circuits B104 to 105
4 and D # P are subjected to general magnetic disk recording processing (addition of ID section, addition of ECC, modulation, etc.). The recording processes D # 1 to D # 4 are the disk I / F 106.
Through 107 to the compression / expansion circuits 109-112. The compression / decompression circuits 109 to 112 are, as shown in FIG.
Timing signals input from the disk I / F 106 via the control system 409 of the disk I / F bus 108 control the controllers 400 to 403, and the disk I / F bus 1
After recording the corresponding video packet from the data system 408 of No. 08 in the memories 404 to 407, the magnetic disk 113
Record at ~ 116.

At this time, the transfer rates of the signals recorded on the magnetic disks 113-116 are the compression / expansion circuits 109-11.
Smoothed in 2 respectively, 1 for memory input
The speed is / 4. In addition, D that has been recorded
#P is recorded on the magnetic disk 117 as it is. At this time, the length of the recording block is an integral multiple of the data area of the sector.
2), (d-2), (e-2), and (f-2), the recording block is written at a timing that is completed by a plurality of sectors.

Next, the basic operation for reproducing the video signal from the magnetic disk, which is the reverse process of FIG. 3, will be described.
As described above, the video signals recorded on the magnetic disks 113 to 116 are read by sequential scanning at the transfer rate of ¼ and are input to the compression / expansion circuits 109 to 112. In the compression / expansion circuits 109 to 112, as shown in FIG. 4, according to the timing signal input from the disk I / F 106 via the control system 409 of the disk I / F bus 108,
Controllers 400 to 403 are magnetic disks 113 to 1
After storing 16 output video packets in the memories 404 to 407, the data system 40 of the disk I / F bus 108 is transmitted at four times the output transmission speed of the magnetic disks 113 to 116.
8 and read FIG. 3 (c-1), (d-1), (e-
1) and (f-1) recording blocks are obtained and are supplied as reproduction video signals to the error processing circuits B104 to 105.

At this time, the data string on the disk I / F bus 108 is obtained in the form of FIG. 5 (b). Error processing circuit B
In 104 to 105, an error is detected for each recording block based on the CRC code added at the time of recording from the reproduced video signal, and the error detection result is supplied to the error processing circuit A 101 via the switch circuits 102 to 103. In addition, the error detection result is supplied to the error block position storage circuit 119.

In the error processing circuit A101, according to the error detection result, the correction data is corrected for 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 118. Further, the corrected reproduced video signals of the # 1 to # 4 layers are supplied to the packet division synthesis circuit 100, and the packets of FIG. 3A are synthesized there and the reproduced video signal is output.

In the disk control circuit 122, an R / W control signal supplied to the apparatus together with a recording video signal,
Based on the control signals such as the sequential scanning timing signal and the initialization signal, the timing signals for sequentially scanning and sequentially recording / reproducing to / from the magnetic disk are supplied to each block, and the recording / reproducing operation to / from each magnetic disk is performed. An R / W control signal for controlling, an access position control signal for designating an access position of a magnetic disk, an initialization signal for initializing a disk of a designated layer, etc. are supplied to the disk I / Fs 106 to 107.

In the disk I / Fs 106 to 107, 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 the disk is initialized.

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 119, the error detection results from the error processing circuits B104 to 105 (FIG. 2A).
In the case of, the diagonally shaded recording blocks a, b, c, d, e, f, g, and h in the m-th sequential scanning section and the information of the recording block position being accessed from the scanning block position register 121 As shown in FIG. 2B, the block position information in which an error has occurred is held at a maximum of four places.

In the correction data storage circuit 118, as shown in FIG.
The correction data supplied from the error processing circuit A101 shown in (c) is stored under the control of the error block rewriting control circuit 120. In the error block rewriting control circuit 120, the scan block position register 1
The information of the recording block position being accessed from 21 and the error block position information from the error block position storage circuit 119 are compared or calculated, and the position of the recording / reproducing head in the (m + 1) th sequential scanning section is the error block position. It is determined that a, b, c, d have been reached.

When the position of the recording / reproducing head reaches the error block position, the error block rewriting control circuit 120
2D, the data of the block is read from the corrected data storage circuit 118 at the timing shown in FIG. 2D, and the switch circuit 102 and the error processing circuit B10 are read.
4. The corrected data is stored in the memory 111 of the # 3 layer via the disk I / F 106 and then written in the sectors corresponding to the recording blocks a, b, c and d of the magnetic disk 115.

The error blocks e, f, g, h in FIG.
Similarly, an error is detected during the (m + 1) th sequential scanning reproduction, and the recording blocks e, f, g, h in the (m + 2) th sequential scanning section are repaired at the timing of access.

In this embodiment, the video packet and the plurality of sectors are divided for recording and reproduction, but it is also possible to record and reproduce in one sector by reducing the size of the video packet.

Further, the redundant disk 117 can be constructed by adding a compression / expansion circuit together with the magnetic disks 113 to 116 and connecting it to the disk I / F 106.

At this time, the error processing circuit A101 collects the parity calculation results of the recording blocks obtained by dividing the video block when recording the video signal, generates a parity recording block, and transmits the parity recording block after outputting all the recording blocks. At the time of reproduction, a parity recording block read before each recording block from the recording / reproducing disk is stored, and an error correction of a recording block input later is performed by using this parity recording block.

[0038]

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. At the time of the m-th sequential scanning reproduction, an error in the recording block in the disc is detected and temporarily stored together with the correction data of the error-corrected recording block.
By recording the correction data in the recording block at the time of progressive scanning reproduction of the recording block after the next, it is possible to provide a disc recording and reproducing method and an apparatus thereof having the following excellent characteristics.

First, when a moving picture database system is realized, high-speed transfer is possible according to the serial operation degree of the recording / reproducing disk. Service can be realized. In addition, the reliability of the recording / reproducing disk, which is the most problematic aspect of system construction, can be improved, and the recorded contents can be restored without interrupting the video service.

Furthermore, since a plurality of recording / reproducing disks are arranged and operated sequentially, it is possible to reduce the size of a video packet to a size that can be recorded in one sector. Therefore, the memory for decompressing the packet is small, and the device can be realized with a relatively small circuit.
A low cost system can be constructed.

[Brief description of drawings]

FIG. 1 is a block diagram showing a main part 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 disc recording / reproducing method of 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 an internal configuration diagram of a compression / expansion circuit according to the present embodiment.

FIG. 5 is a signal multiplexing configuration diagram according to a conventional recording / reproducing method.

FIG. 6 is a tracking operation diagram of a magnetic disk device according to a conventional recording / reproducing method.

FIG. 7 is a packet configuration diagram for multiplexing video blocks.

[Explanation of symbols]

 100 Packet division / synthesis circuit 101 Error processing circuit A 102 Switch circuit 103 Switch circuit 104 Error processing circuit B 105 Error processing circuit B 106 Disk I / F 107 Disk I / F 108 Disk I / F bus 109-112 Compression / expansion circuit 113- 117 magnetic disk 118 corrected data storage circuit 119 error block position storage circuit 120 error block rewriting control circuit 121 scanning block position register 122 disk control circuit 400-403 controller 404-407 memory 408 data system 409 control system

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location H04N 5/85 Z 7734-5C 5/93 7734-5C H04N 5/92 D 7734-5C 5/93 Z

Claims (4)

[Claims] 1. A video signal is divided into a plurality of video blocks,
A disk recording / reproducing method of rearranging and recording in a predetermined format and simultaneously reproducing video signals of a plurality of phases by high-speed reproduction, wherein L video blocks (L is an integer of 1 or more) are recorded on the time axis. Divide into blocks, L
A disc recording / reproducing method characterized in that each recording block is time-axis processed and divided into a plurality of recording / reproducing discs in units of recording blocks for recording. 2. Position information of a recording block in which an error is detected during m-th sequential scanning reproduction (m is an integer of 1 or more),
The correction data of the recording block, which is error-corrected using the position information and the reproduction data from the plurality of discs, is temporarily stored, and the (m) th data is 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 sequentially scanning and reproducing the recording block of +1) and subsequent recording blocks. 3. A plurality of recording / reproducing discs including redundant recording / reproducing discs, error detecting means for detecting an error in reproduced data from each recording / reproducing disc, and an error block for holding position information of a recording block in which an error has occurred. Position storage means, correction data generation means for generating correction data of the recording block by output from the plurality of recording / reproducing disks, correction data storage means for holding correction data of the recording block, An error block re-recording unit for recording the scanning block position register indicating the position of the recording block and the correction data read from the correction data storage means according to the output of the scanning block position register and the output of the error block position storage means. A disc recording / reproducing apparatus comprising: a writing control unit. 4. A packet division / synthesis circuit for dividing and synthesizing packets in which video signals are multiplexed, a magnetic disk for recording the video signals, and error processing for calculating parity from video information to generate parity data. Circuit A
A correction data storage circuit for holding the correction data of the video signal; a switch circuit for switching the outputs of the error processing circuit A and the correction data storage circuit; an error processing circuit B for calculating a CRC code; and an error occurrence. Error block position storage circuit for holding the position information of the video signal, a scanning block position register indicating the position of the video signal during progressive scanning reproduction, and an error block for recording the correction data read from the correction data storage circuit. A rewrite control circuit, a disk interface for performing a recording process on the magnetic disk, a disk control circuit for controlling the error block rewrite control circuit, the scan block position register, and the disk interface, and the video signal for the magnetic field. It plays the role of adjusting the transmission speed when recording and reproducing from the disc. Disk recording and reproducing apparatus characterized by comprising a that compression and expansion circuit.