KR100196927B1 - Error correction method of digital video recording/reproducing apparatus - Google Patents

Abstract

The present invention relates to an error correction method of a digital video signal recording / reproducing apparatus. An object of the present invention is to improve the processing speed of a program by reducing the error correction time for one ECC block data by changing the error correction order and increasing the number of data that is error corrected within the same time. Therefore, the digital data arranged by the RS encoding method, the PO codeword assigned to the data so as to correct an error occurring in the data, and the data so as to correct an error occurring in the data and the PO code word. And an error correction method in decoding an ECC block including a PI codeword assigned to the PO codeword: after performing an error correction process on the PO codeword included in one ECC block data, An error correction method of a digital video signal recording / reproducing apparatus is proposed to perform an error correction process for a PI codeword.

Description

Error correction method of digital video signal recording / playback device

The present invention relates to an error correction method of a digital video signal recording / reproducing apparatus, and more particularly, to a digital video signal such as a digital video disc player (hereinafter, abbreviated as 'DVDP'). In the recording / playback apparatus, error correction code block data (hereinafter, abbreviated as 'ECC block data') stored in a digital video disc (hereinafter, abbreviated as 'DVD'). The present invention relates to an error correction method of a digital video signal recording / reproducing apparatus in which the error correction process is changed.

That is, according to the present invention, an error correction process of a Parity Outer Codeword is first performed on an ECC block described above, and an error correction process of a Parity Inner Codeword is performed later. An error correction method of a playback apparatus.

[0003] In general, digital video signal recording / reproducing apparatus such as DVD or the like tends to cause large-scale aggregation errors due to recording / reproducing heads, optical pick-up contamination, recording medium (disc) defects and damage. Therefore, countermeasures against such collection errors are very important in the digital video signal recording / reproducing process.

There are various methods for countermeasures of aggregation error, but interleave is most commonly used. Interleaving is a method of distributing word arrays of consecutive digital data according to a predetermined rule, and writing them by rearranging them so that bits that were initially adjacent to each other are not adjacent to each other. When data is recorded in such an interleaved manner, it is possible to disperse intensive and continuous error occurring continuously and greatly improve the error detection and correction capability of the system.

In the operation of a typical DVDP, the encoding process of receiving data and adding additional information (Redundancy) to protect the input data from errors and recording the input data and the additional information on a recording medium such as a DVD, and recording By reading the data recorded on the medium and referring to the additional information, a decoding process is performed to restore the original data by protecting the data from various errors that may occur during storage and playback.

In this case, the additional information includes a PO (Parity Outer) and a PI (Parity inner) so as to correct an error of data. One ECC block data format including data and additional information is shown in FIG. 1.

An ECC block is a code that is configured to correct an error in the data. It represents a code (data + PO + PI) or redundant information assembled to detect and correct an error contained in the data. Not only can you detect when an error is caused by noise or other causes within acceptable and unacceptable expressions, but it is also possible that some of the expressions containing errors are equivalent to the original acceptable expressions. One of the expressions is the code that can correct the error.

The ECC block is determined in 1960 according to the RS coding scheme proposed by I. S. Reed and G. Solomon, and the data error is corrected according to the RS decoding scheme. According to the RS encoding and decoding method, there is an advantage in that a simultaneous error and a scattering error can be simultaneously corrected.

As shown in FIG. 1, one ECC block has 182 PI codewords (172 data + 10 parity) in the horizontal direction, and 208 PO codewords (192 in the vertical direction). +16 parity data exists.

A typical encoding process is designed to perform an encoding process for a PO codeword first, and then an encoding process for a PI codeword later. For this reason, the decoding process is performed in the reverse order with respect to the above-described encoding process. That is, in the decoding process, the decoding process for the PI codeword is first performed, and then the decoding process for the PO codeword is performed later. In addition, after performing error correction for one ECC block unit every time, if the error flag is expressed as '1' by checking the entire error flag (when an error exists in the ECC block), PI is again displayed. It is designed to perform the decoding process for codewords.

The above-described process will be described in detail with reference to FIG. 2. First, the PI codeword of the corresponding ECC block is corrected 208 times (S1). Thereafter, it is checked whether the error flag of the corrected ECC block data is '1' (when an error exists) (S2), and if it is determined in step 2 (S2) that the error flag is not '1' (error correction of data) After the completion of the error correction of the corresponding ECC block without performing the correction process of the PO codeword, the error correction of the next ECC block is performed.

If it is determined in step 2 (S2) that the error flag is '1', the PO code word of the ECC block is corrected 182 times (S3). Thereafter, it is checked whether the error flag of the corrected ECC block data is '1' (if an error exists) (S4), and if it is determined in step 4 (S4) that the error flag is not '1' (error correction of data) When the error correction is completed, the error correction of the corresponding ECC block is performed, and then error correction of the next ECC block is performed.

If it is determined in step 4 (S4) that the error flag is '1', it indicates that all the errors of the ECC block data are not corrected, and therefore, returns to step 1 (S1) and all the steps after step 1 (S1). Repeat the process.

However, when error correction is to be performed in real time in a state having a complicated memory access structure such as a DVD, the number of error corrections is limited. In other words, in order for the DVD to perform a real-time processing operation, the error correction process cannot be continued until all errors are corrected. Therefore, if a real-time processing operation is required, even if an error remains, the error correction process must be forcibly stopped.

In general, a PI codeword is a codeword capable of correcting an error of 5 bits, and a PO codeword is a codeword capable of correcting an error of 8 bits. In order to correct an error according to a conventional ECC block, the PI code word → PO code word → PI code word → PO code word →. Therefore, the amount of error corrected within the limited time according to this order is 5 + 8 + 5 + 8 +... Bit. According to the error correction procedure described above, the number of corrections of the PI codeword is equal to or larger than the number of corrections of the PO codeword. Therefore, the PI code word → PO code word → PI code word →. When corrected in order, PO code word → PI code word → PO code word →. There was a problem that it is inefficient than the case of correcting in order.

Accordingly, an object of the present invention is to solve the above-described problem, and an object of the present invention is to change an error correction order to reduce error correction time for one ECC block data, thereby improving digital program signal recording. / Provides an error correction method for a playback device.

Another object of the present invention is to provide an error correction method of a digital video signal recording / reproducing apparatus which changes the error correction order to increase the number of data that is error corrected within the same time.

1 is a diagram showing one ECC block data format of a digital video signal recording / reproducing apparatus according to a conventional RS method;

2 is an operation flowchart showing an error correction process of a conventional digital video signal recording / reproducing apparatus;

3 is a schematic block diagram of an error correction apparatus for performing an error correction method of a digital video signal recording / reproducing apparatus according to the present invention;

4 is a flowchart illustrating an error correction process of the digital video signal recording / reproducing apparatus according to the present invention.

<Description of the symbols used in the main parts of the drawing>

1: storage medium 2: ECC (Error Correcting Code)

3: PO error correction decoding unit 4: reverse shuffling unit

5: PI error correction decoder

A feature of the present invention for achieving the above object is the digital data arranged by the RS encoding scheme, the PO codeword assigned to the data so as to correct an error occurring in the data, the data and the An error correction method in the process of decoding an ECC block composed of the data and a PI codeword assigned to the PO codeword so as to correct an error occurring in a PO codeword, the PO included in one ECC block data. An error correction method of a digital video signal recording / reproducing apparatus for performing an error correction process for a codeword and then performing an error correction process for the PI codeword.

In the aspect of the present invention, after performing the error correction process for the PO codeword, if there is no error flag, error correction process for the PI codeword is omitted, error correction process for the next ECC block data It is desirable to carry out.

In addition, after performing the error correction process for the PI codeword, if there is an error flag, return to the error correction process for the PO codeword to the error correction process for the PO codeword and the PI codeword It is desirable to repeat the error correction process.

Hereinafter, a preferred embodiment of an error correction method of a digital video signal recording / reproducing apparatus according to the present invention will be described in detail with reference to the accompanying drawings.

3 is a schematic block diagram of an error correction apparatus for performing an error correction method of a digital video signal recording / reproducing apparatus according to the present invention.

As shown in FIG. 3, the error correction apparatus according to the present invention includes a storage medium 1 that sequentially receives and stores an ECC block data format recorded on a digital video signal recording medium such as a DVD, and the storage medium 1. ECC block 2 which detects PI code word and PO code word from one ECC block data format among a plurality of ECC block data formats stored in the &lt; RTI ID = 0.0 &gt; .

On the other hand, the ECC unit 2 described above includes a PO error correction decoding unit 3 for error correction of the PO codeword from one ECC block applied from the storage medium 1 and then removing the PO parity from the PO codeword. A PI codeword from the reverse shuffling section 4 that shuffles the error corrected data by the PO error correction decoding section 3 and the data shuffled backward by the reverse shuffling section 4. The PI error correction decoder 5 removes PI parity from the PI codeword after error correction.

The operation of the present invention having the above-described configuration will be described with reference to FIG. 4 as follows.

The ECC block data read out from the digital video signal recording medium is sequentially stored in the storage medium 1. The storage medium 1 detects one ECC block data among sequentially stored ECC block data, and outputs the ECC block data to the PO error correction decoding unit 3 configured in the ECC unit 2.

The PO error correction decoder 3 corrects the P0 codeword of the ECC block 182 times by using one ECC block data applied from the storage medium 1 (S5). Then, it is checked whether the error flag of the corrected ECC block data is '1' (when an error exists) (S6), and if it is determined in step 6 (S6) that the error flag is not '1' (error correction of data) When the process is completed, the error correction of the corresponding ECC block is terminated without outputting the PI codeword correction process, and the final corrected data is output. Then, the error correction of the next ECC block is performed.

If it is determined in step 6 (S6) that the error flag is '1', the error-corrected ECC block data is initially shuffled by the reverse shuffling section 4.

Here, the error correction process related to the reverse shuffling operation will be briefly described. The digital data errors include sporadic random errors and burst errors that occur continuously and intensively at a specific location. There is. Among these, as mentioned above, the 'interleave' method has been proposed, and if the data is recorded in an interleaved manner, scattering errors can be dispersed by intensive and continuous error generation. The ability to detect and correct errors can be greatly improved. Such interleaved method is referred to as 'shuffling' in digital method, and each term has the same meaning in terms of 'error detection and correction'.

Since data is scattered and recorded according to this shuffling method on the digital video signal recording medium, the inverse shuffling section 4 arranges the data recorded by the shuffling method again in the original arrangement.

The ECC block data rearranged through the reverse shuffling unit 4 is applied to the PI error correction decoding unit 5, and the PI error correction decoding unit 5 is the PI code of the corresponding ECC block applied from the reverse shuffling unit 4. The word is corrected 208 times (S7). Thereafter, it is checked whether the error flag of the corrected ECC block data is '1' (when an error exists) (S8), and if it is determined in step 8 (S8) that the error flag is not '1' (error correction of data) When the error correction is completed, the error correction of the corresponding ECC block is performed, and then error correction of the next ECC block is performed.

If the error flag is determined to be '1' in step 8 (S8), it indicates that all the errors in the ECC block data are not corrected. Therefore, the process returns to step 5 (S5) and all the steps after step 5 (S5). Repeat the process.

According to this process, if the PO codeword and PI codeword are corrected an odd number of times, the error correction time is minimized because the amount of error-corrected data is increased than error correction of the PI codeword after error correction of the PI codeword. Can be. That is, in the case of performing error correction in the order of PO code word → PI code word → PO code word, the total number of error correction data is 21 (8 + 5 + 8 = 21). However, when error correction is performed in the order of PI code word → PO code word → PI code word at the same time, the total number of error correction data is 18 (5 + 8 + 5 = 18). Therefore, if error correction is first performed on the PO codeword, more data can be error corrected at the same time.

In addition, when the PO codeword and the PI codeword are corrected an odd number of times, an error correction time can be reduced than when the PO codeword is error-corrected after error correction of the PI codeword. In other words, when error correction is performed in the order of PO codewords → PI codewords → PO codewords, the number of error corrections is 572 times (182 + 208 + 182 = 572). However, when error correction is performed in the order of PI code word → PO code word → PI code word at the same time, the total number of error correction times is 598 (208 + 182 + 208 = 598). Therefore, if error correction is first performed on the PO codeword, the time required for error correction of one ECC block can be reduced.

As a result, according to the error correction method of the digital video signal recording / reproducing apparatus according to the present invention as described above, the error correction operation is first performed on the PO codeword, and then the error correction operation is performed on the PI codeword. In addition, there is an advantage in that the time required for error correction of one ECC block data can be reduced while correcting more data errors in the same time.

In addition, since more data errors can be corrected within the same time, there is an advantage that the processing speed of data can be improved.

Claims (3)

Digital data arranged by an RS encoding scheme, a PO codeword assigned to the data to correct an error occurring in the data, and the data and the data to correct an error occurring in the data and the PO codeword. In the error correction method in decoding an ECC block consisting of a PI codeword assigned to a PO codeword: And performing an error correction process for the PO codeword included in one ECC block data, and then performing an error correction process for the PI codeword. The method according to claim 1, After performing the error correction process for the PO code word, if the error flag does not exist, the error correction process for the PI code word is omitted, and the error correction process for the next ECC block data, characterized in that to perform Error correction method of digital video signal recording / reproducing apparatus. The method according to claim 1, After performing the error correction process for the PI codeword, if there is an error flag, return to the error correction process for the PO codeword, error correction process for the PO codeword and error correction for the PI codeword Error correction method of a digital video signal recording / reproducing apparatus, characterized in that to repeat the process.