JP2666258B2 - Signal recording method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in the following order. A. Industrial application fields B. Summary of the invention C. Conventional technology D. Problems to be solved by the invention E. Means for solving the problems F. Action G. Embodiment G-1. Example data structure (FIG. 1) G-2. Recording format (FIG. 2) G-3. Other embodiments (FIG. 3) H. Effects of the invention A. Industrial application field More particularly, the present invention relates to a signal recording method for recording a data signal on a recording medium in which a recording area is divided into recording blocks such as sectors, such as a disk-shaped recording medium. B. Summary of the Invention The present invention relates to a signal recording method for recording a data signal on a recording medium whose recording area is divided into recording blocks such as sectors, wherein a data signal to be recorded is an audio data signal, a video data signal, or the like. In the case of a data signal having temporal continuity and having a correlation between respective data as described above, the data signals sequentially supplied are distributed so as to be distributed to two or more recording blocks of the recording medium. By recording, even if the reliability of data is reduced in recording block units due to a burst error or the like, interpolation using data of another recording block can be performed. C. Prior Art Various types of signal recording media are known, but a recording medium in which a recording area is divided into recording blocks called sectors, such as a magnetic disk, an optical disk, and a magneto-optical disk, is not known. Since it is easy to realize so-called random access and easy to manage recording data, it is being widely used. In recent years, optical recording media such as optical disks and magneto-optical disks using an optical or magneto-optical signal recording / reproducing method having an extremely large recording capacity have been developed and supplied to the market. These optical recording media were obtained by converting a temporally continuous analog signal into a digital signal, such as an audio data signal or a video data signal, by utilizing the size of the storage capacity. It is also conceivable to record a data signal having high correlation between data. Here, the recording capacity of such an optical disc or the like is extremely large, for example, about several hundred megabytes or more.
Error countermeasures against burst errors and the like are important. For this reason, it is common practice to add error detection or error correction codes to data to be recorded. There are various methods of error correction encoding for this purpose. For example, data of one sector of a disk is arranged in a two-dimensional matrix of m rows and n columns, and each row data of the two-dimensional array data is subjected to the first data. A so-called product code formed by generating and adding one error correction code and generating and adding a second error correction code to the data of each column, and each data in the row direction of the m rows and n names of the two-dimensional array data. A code or the like that adds an error correction code to each stream and performs reading and writing of data in the column direction is used. D. Problems to be Solved by the Invention By the way, temporally continuous and highly correlated data such as the above-mentioned audio data and video data is completed in data processing such as error correction processing in units of recording blocks such as the above sectors. In the case of being recorded in such a form that
An error exceeding the error correction capability in one sector may occur due to the occurrence of a burst error due to a defect of the medium or the like. In this case, all data in the sector becomes unreliable data, and Continuity cannot be obtained, and the signal quality deteriorates. That is, for example, consider the case where stereo audio PCM data with a sampling frequency of 48 kHz and one sample of 16 bits is recorded in a recording format of 1024 bytes per sector. When there is no data, about
As a result, a signal of 5.3 msec cannot be obtained, and interpolation processing can hardly be performed effectively with respect to such a long-time signal loss, resulting in a very hard to hear sound. In view of the above-mentioned conventional problems, the present invention records a data signal having a strong correlation between data such as an audio data signal on a recording medium in which a recording area is divided into recording blocks such as sectors. In this case, an object of the present invention is to provide a signal recording method capable of performing an effective interpolation process even if the reliability of all data in one sector is lost and improving the quality of a reproduced signal. E. Means for Solving the Problems In order to achieve the above object, the signal recording method according to the present invention has a plurality of concentrically or spirally formed recording tracks having a size equal to each other in advance. In a signal recording method for sequentially recording data signals on a disk-shaped recording medium divided into recording blocks, data signals to be recorded are determined according to whether they are interpolable data having correlation with each other or non-interpolable data. While changing the data signal recording mode for the recording block,
In the case of the correctable data, the sequentially supplied data is distributed and divided into two or more of the recording blocks on the recording medium to form blocks. In the case of the non-interpolable data, The supplied data is sequentially divided into blocks corresponding to the recording blocks, and after performing a predetermined error correction encoding process for each of the divided data, the data is recorded on the recording track corresponding to the recording block. It is characterized by doing. F. Operation Since interpolable data sequentially supplied is recorded dispersedly over two or more recording blocks, even if the reliability of the data in one recording block is lost, other recording blocks Can be interpolated by using the above data. G. Embodiment Hereinafter, as an embodiment of the signal recording method of the present invention, an example in which data is recorded on a magneto-optical disk will be described with reference to the drawings. FIG. 1 shows a case where a data signal recorded on a magneto-optical disk by a signal recording method according to an embodiment of the present invention is a data signal such as an audio data signal which has a high correlation between data and can be subjected to interpolation processing. 2 shows an example in which a data structure is shown and an error correction encoding process using a so-called product code is performed.
FIG. 2 shows the recording format of the magneto-optical disk 1. On the magneto-optical disk 1, a plurality of concentric recording tracks (or spiral recording tracks) 2 are formed. The recording track 2 is divided into a plurality of recording blocks or sectors as recording units. Depending on whether the data signals sequentially recorded in such a plurality of sectors are interpolable data having a correlation with each other such as the audio signal or the like and non-interpolable data such as general computer data, The recording mode for the sector is changed, and in the case of the interpolable data, the sequentially supplied data signal is distributed so as to be distributed to two or more sectors, that is, for example, the odd number of the input data is divided into two sectors. The data is recorded in such a manner that the second data and the even data are alternately distributed. G-1. Data Structure of One Embodiment (FIG. 1) Here, in one embodiment of the present invention, the case where the data signal to be recorded on the magneto-optical disk is the above-mentioned interpolable data signal will be described. This will be described in detail with reference to FIG. The sectors 2k and 2k + 1 in FIG. 1 correspond to the even and odd sectors on the track 2 of the magneto-optical disk 1. In a magneto-optical disk, the unit data amount recorded in one sector on a recording track is, for example, 512 bytes as a standard considering that the magneto-optical disk is used as an information recording medium for a computer. . This one
FIG. 1 shows an example of the data structure when the sector is 512 bytes. That is, when focusing on the data structure for one sector, the original valid data is 512 bytes,
After the data, 16 bytes of additional information are added to become 528 bytes, which are divided into 44 bytes in a row direction and 12 bytes in a column direction (44 × 12 = 52).
8), they are arranged two-dimensionally. That is, 12
A two-dimensional matrix array of 44 rows is formed. Here, 12 bytes out of the 16 bytes of the additional information are reserved information, for example, link information to the next sector, data identification information, and the like are inserted. In addition, a 4-byte error detection code EDC is generated for a total of 524 bytes of data including the reserved area data, and inserted into the last 4-byte area of 16 bytes of additional information. With the first error correction code C ₁ of 4 byte each is added to more than 528 bytes of two-dimensional array data of each line of data (44 bytes), an error correction code C ₁ of the first is added 2-dimensional array data (576 bytes) are added second error correction code C ₂ of each 2 bytes for data (12 bytes) of each column of, in total 672 bytes, the 14 rows 48 columns product code Is configured. Here, the first
As the second error correction code, for example, C ₁ (48,4
4) Reed-Solomon codes and C ₂ (14,12) Reed-Solomon codes may be used. The two-dimensional array data having such a product code configuration is written and read one row at a time in the row direction, and is sequentially recorded in the one sector on the disk. Here, if the data signal to be recorded cannot be interpolated as in the case of ordinary computer data, the sequentially input data is divided into blocks of 512 bytes, and the error correction encoding process using the product code is performed. To obtain data to be recorded in one sector. If the data signal to be recorded is a data signal that can be interpolated such as the audio signal or the like, data between blocks corresponding to a plurality of sectors is used. After the input data has been distributed in a distributed manner, the error correction encoding process using the product code is performed for each block to obtain each sector record data. That is, for example, as shown in FIG.
In the case of performing the distributed data distribution for 2k and 2k + 1, the data sequentially supplied with time is divided into 1024 bytes for the two sectors, and the 1024-byte input data sequence D ₀ , D _1, D ₂ and ...... D _1023, by distributing sequentially alternately to the two sectors 2k and 2k + 1, the data D of the even numbered _{0, D 2, D 4 ......} D 1022 is an even-numbered sector 2k
The odd-numbered data D ₁ , D ₃ , D ₅ ... D ₁₀₂₃ are respectively allocated to the odd-numbered sector 2k + 1. That is, the input data is substantially equally distributed and distributed to each of the sectors 2k and 2k + 1. As described above, the input data is alternately distributed, and the data of each sector is made 512 bytes each. Then, the error correction coding process using the product code described above is performed for each data of each sector, as shown in FIG. Two-dimensional array data for two sectors is obtained. These sectors 2k and 2k + 1
Are recorded on the track 2 of the magneto-optical disk 1, respectively.
It is sequentially recorded in the corresponding sector above. G-2. Recording Format (FIG. 2) Next, a recording format on the magneto-optical disk in which the two-dimensional array data is recorded will be schematically described with reference to FIG. In FIG. 2, the magneto-optical disk 1 has a so-called 5
In the case of the inch type, the diameter is about 13 cm, and one side has a storage capacity of 300 Mbytes or more. This disc 1
The track 2 is rotated at a constant angular velocity, and as one track per rotation, for example, concentrically or spirally.
And data is recorded. 18 tracks per side
2,000 to 20,000, and each track is
As shown in (1), it is divided into (n + 1) sectors, for example, 32 sectors. Here, each of the sectors 2k and 2k in FIG.
+1 is obtained by setting the value of k to 0, 1, 2,...
Is 0, it corresponds to sectors 0, 1 in FIG. 2, and when k is 1, it sequentially corresponds to sectors 2, 3 in FIG. As the value of k, an integer value from 0 to (n-1) / 2 is used. As described above, when the supplied data signal is correlated and interpolable data, the input data is sequentially divided into two sectors 2k and 2k + 1, and each data of these sectors 2k and 2k + 1 is divided. Are sequentially recorded in corresponding sectors on the track 2 of the magneto-optical disk 1. Therefore, at the time of signal reproduction, even if a burst error occurs due to a medium defect or the like and the reliability of all data in one sector (for example, sector 2k) is lost, the other sector (for example, sector 2k + 1)
The data of the error-occurring sector can be obtained by normal interpolation processing, and the deterioration of the reproduced signal can be prevented. G-3. Another Embodiment (FIG. 3) Next, another embodiment of the present invention will be described with reference to FIG. In this embodiment, an example of a code system in which an error correction code is added only to each data sequence in the row direction of two-dimensional data is shown.
Bytes. In such a coding system, since the sequence length in the row direction which is the direction of the generation sequence of the error correction code is relatively long (for example, about 100 bytes), LDC (Long Dist) is used.
ance code), and the interleave depth is the length in the column direction. In FIG. 3, the data recorded in one sector will be described first. After 16 bytes of additional information are added to the original valid data (1024 bytes) of one sector, the data becomes 1040 bytes. The two-dimensional matrix array data of 130 (= 128 + 2) bytes in the row direction and 8 bytes in the column direction are formed by dividing every eight bytes in the direction. Here, the 16-byte additional information may be composed of, for example, reserve information and an error detection code EDC, as in the embodiment of FIG. For each row (130 bytes) of the two-dimensional array data thus obtained, 16
A so-called LDC data is formed by generating and adding a byte error correction code ECC, for example, a C (146,130) Reed-Solomon code. The two-dimensional array data having such an LDC configuration is read and written one by one in the column direction, and is sequentially recorded in each sector on the recording track 2 (see FIG. 2) of the disk. Here, if the data to be recorded is data having strong correlation and can be interpolated, such as audio signal data, the sequentially supplied data is distributed so as to be distributed to two or more sectors. In the example of FIG. 3, even-numbered data and odd-numbered data of data sequentially supplied to two sectors 2k and 2k + 1 are alternately distributed. That is, when the input data strings D ₀ , D ₁ , D ₂ ... Sequentially supplied with time are distributed and distributed to the two sectors 2k and 2k + 1, the even-numbered data D ₀ ,
D _2, D ₄ ...... into sectors 2k, odd-numbered data D _1, D _3, D ₅
.. Are alternately allocated to the sectors 2k + 1 so that the input data is distributed to the sectors 2k and 2k + 1. In this manner, the input data is alternately distributed, and when the data of each sector becomes 1024 bytes, the so-called LD described above is used for each data of each sector.
An error correction encoding process by C is performed to obtain two-sector two-dimensional array data as shown in FIG. Each data of these sectors 2k and 2k + 1 is recorded in the corresponding sector on the track 2 of the magneto-optical disk 1, respectively. In the embodiment of FIG. 3 as well, even when all data in one sector, for example, sector 2k, cannot be corrected due to a burst error or the like during signal reproduction, data in another sector, for example, sector 2k +, is used. Normal interpolation processing can be performed. Note that the present invention is not limited to only the above-described embodiment. For example, in each of the above embodiments, input data to be used for recording is distributed in advance to a plurality of sectors, and then error correction encoding is performed for each data in each sector. After performing the error correction coding process in each sector, when recording in each sector of the recording medium, the recording data of a plurality of sectors is distributed and distributed to the plurality of sectors on the recording medium. It may be recorded. In this case, for example, 2
When performing distributed data distribution between sectors, an error that has occurred in one sector on the recording medium has actually occurred over two sectors, and an error per sector has occurred. , The error correction capability is remarkably improved. In addition, it is easy to realize distributed distribution of data over three or more sectors. For example, when data is distributed to three sectors, each of the input data strings 3i, 3i
+1, 3i + 2 data (i = 0, 1, 2,...)
What is necessary is just to distribute and distribute to one sector sequentially. In addition, various changes can be made without departing from the spirit of the present invention. For example, the sequence length of the two-dimensional array data in the row direction and the column direction, the data amount in one sector, and the like are the same as those of the above embodiment. Needless to say, it can be set arbitrarily without being limited to numerical values. H. Effects of the Invention According to the signal recording method of the present invention, when recording a highly interpolable data signal such as an audio signal on a recording medium divided into recording blocks such as sectors, a burst error occurs. One recording block (1
Even if all data in the sector) is unreliable,
Interpolation processing can be performed using data of another recording block, and deterioration of a reproduced signal can be prevented. In the case of data that cannot be interpolated, the supplied data is sequentially divided into blocks and recorded on a recording medium without dispersing the data into two or more recording blocks, so that processing related to dispersion is unnecessary. Higher processing speed or higher access speed can be achieved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing a data structure of two sectors to be recorded by a signal recording method according to an embodiment of the present invention;
FIG. 3 is a schematic diagram showing a recording format of a magneto-optical disk in this embodiment, and FIG. 3 is a diagram showing a data structure of two sectors applied to another embodiment of the present invention. 1 ... Magneto-optical disk 2 ... Track

Claims (1)

(57) [Claims] In a signal recording method for sequentially recording data signals on a disk-shaped recording medium in which a plurality of recording tracks formed concentrically or spirally are divided into a plurality of recording blocks having the same size in advance, a data signal to be recorded However, the data signal recording mode for the recording block is changed depending on whether the data is interpolable or non-interpolable data having a correlation with each other. In the case of the interpolable data, the data is sequentially supplied. Data is distributed and divided into two or more recording blocks on the recording medium to form blocks. In the case of non-interpolable data, supplied data is sequentially blocked corresponding to the recording blocks. After performing a predetermined error correction encoding process for each block of data, the recording block A signal recording method for recording on the above-mentioned recording track corresponding to the above.