KR0155736B1 - Digital recording/reproducing method and apparatus - Google Patents

Abstract

The present invention relates to a digital recording and reproducing apparatus method and apparatus, and more particularly, to a digital recording and reproducing method and apparatus for coding external code parity data in a two-dimensional error correction code.

To this end, in order to form an error correction code block for error correction, a plurality of (integer N) data blocks are formed, and compressed data of the data blocks are read in zigzag per sync block, and the outer code parity data area of the integer N data blocks The outer code parity data is sequentially distributed coded into the.

Therefore, there is an effect that the external code error correction processing efficiency can be improved rather than coding into one unit block.

Description

Digital recording and reproducing method and apparatus

1 is a block diagram of an error correction code for explaining the present invention.

2 is a diagram for adding inner code parity data and outer code parity data of a conventional air correction code.

3 is a diagram illustrating an outer code parity data coding scheme according to an embodiment of the present invention.

4 is a block diagram of a digital recording and reproducing apparatus according to the present invention.

5 is a detailed block diagram of the RS coding means of FIG.

6 is a detailed block diagram of the first to third data control blocks of FIG.

7 shows the data format of a record carrier according to the present invention;

The present invention relates to a digital recording and reproducing apparatus method and apparatus, and more particularly, to a digital recording and reproducing method and apparatus for coding an external code parity data in a two-dimensional error correction code.

In general, the two-dimensional error correction code is to ensure the integrity of the data in the transmission of data in a block unit having a plurality of subclocks.

In digital tape cassette recorders (D-VCRs) or high-definition tape cassette recorders (HD-VCRs), two-dimensional error correction codes are used to correct random errors and internal parity data to correct random errors and external to correct burst errors. Contains call parity data.

1 shows a block diagram of an error correction code (hereinafter referred to as ECC) for explaining the present invention.

In FIG. 1, an ECC block is composed of a sync code SYNC, an identification code ID, image compression data, an inner code parity data, and an outer code parity data. The sync code is a code indicating the start and end of a block, the identification code is a code including a bit separating audio / video data, a bit separating data / external code, a block address, and the like. The image compression data is an input data. An image is code compressed at a predetermined bit rate, outer code parity data is parity data for image compression data, and inner code parity data is identification code and image compression data or identification code and outer code parity data. Parity data.

FIG. 2 is a diagram for adding parity data to the inner code parity data of the conventional error correction code and to the outside.

FIG. 2 (a) shows a diagram for adding outer code parity data, and FIG. 2 (b) shows a diagram for adding inner code parity data.

In an encoder that encodes image data and records it on a recording medium, external code parity data is first added and then internal code parity data is added.

To add outer code parity data, compressed data is read in the vertical direction. The read data is coded into the outer code parity data area in one data block. Here, the outer code parity data may correct an error by P rows of (K + P) rows.

To add the inner code parity data, the identification code (ID) and compressed data group or the identification code and outer code parity data group are read in the horizontal direction. The read data is coded into the inner code parity data area in one data block.

However, in coding the external code parity data in the conventional error correction code, since a single block is coded to correct an error, the error correction processing efficiency decreases when there are many errors caused by damage to the recording medium. there was.

Accordingly, an object of the present invention is to provide a digital recording and reproducing method and apparatus for distributing external code parity data into a plurality of data blocks in order to solve the above problems.

In order to achieve the above object, the image data of the screen is compressed and encoded to reduce the bit rate, and the compressed data is inserted into the sync code and the identification code to form an error correction code block for error correction. In a digital recording and reproducing method of recording on a plurality of tracks of a magnetic tape serving as a medium and reproducing data recorded from the magnetic tape, a plurality of (integer N) data blocks are formed to form an error correction code block for error correction. And sequentially compresses the outer code parity data in the outer code parity data area of the integer N data blocks by zigzag reading the compressed data of the data block for each sync block.

In order to achieve the above object, a digital recording and reproducing apparatus comprising an encoder for encoding image data on a screen and recording on a magnetic tape, and a decoder for picking up and decoding recording data from the magnetic tape to restore original image data. The encoder comprises: pre-processing means for converting input image data into digital and transmitting the desired format file; Data compression encoding means for compressing and encoding data; Error correction decoding means for reading the compressed coded data, distributing and coding external code parity data into a plurality of data blocks, adding a sync code and an identification code, and adding internal code parity data; Channel modulation means for modulating the data to transmit the data on a channel, the decoder comprising: channel decoding means for channel decoding the data picked up from the magnetic tape; Error correction decoding means for error correction of the channel decoded data through two-dimensional Reed-Solomon decoding; Data decompression / decoding means for decompressing the error corrected and decoded data to restore image data; And a reverse preprocessing means for performing the reverse function of the pretreatment means.

Hereinafter, with reference to the accompanying drawings will be described in detail with respect to the present invention.

3 is a diagram illustrating an outer code parity data coding scheme according to an embodiment of the present invention.

3 shows an example of adding outer code parity data to two data blocks. It is assumed that the third (a ') is the first data block and the third (b') is the second data block.

Next, a process of adding outer code parity data of FIG. 3 will be described.

Next, a process of adding outer code parity data of FIG. 3 will be described.

First, it reads the "1" compressed data represented by the triangle of the first sync block of the first data block, and then reads the "2" data represented by the triangle of the second sync block of the second data block, and again reads the first data block. The first data block and the second data block are read by reading “3” data represented by the triangle of the third sync block of the second block and reading “4” data represented by the triangle of the fourth sync block of the second data block. Each sync block is zigzag-read to read the data indicated by the triangle of the N-th sync block. External code parity data is added to the read N compressed data.

When adding the outer code parity data, m outer code parity data are added in a zigzag to the outer code parity data area of the first data block and the outer code parity data area of the second data block, respectively. That is, "N + 1" outer code parity data indicated by triangles is added to the outer code parity data area of the first data block, and "N + 2" outer code parity data is added to the outer code parity data area of the next second data block. Finally, "N + m" outer code parity data is added to the outer code parity data area of the second data block.

Next, the compressed data indicated by the circle is added in the same manner as the above-described external code parity data.

4 shows a block diagram of a digital recording and reproducing apparatus according to the present invention.

In FIG. 4, the block diagram of the digital recording / reproducing apparatus is largely divided into the encoder 90 and the decoder 100. In FIG.

The encoder 90 performs a function of receiving original image data as input and performing compression. The encoder 90 includes a preprocessing means 10, a data compression encoding means 20, an RS encoding means 30, and a channel modulating means 40.

The decoder 100 picks up the compressed data and generates the restored image data. The decoder 100 includes a channel demodulation means 50, an RS decoding means 60, a data decompression decoding means 70 and a reverse preprocessing means 80.

Next, the operation of the block diagram shown in FIG. 5 will be described.

First, the encoder 90 will be described. The preprocessing means 10 performs filtering, separation of luminance signals and chrominance signals, and analog-to-digital conversion functions. That is, the input image data is converted into a digital signal and the luminance signal Y and the color difference signals R-Y and B-Y are generated in a 4: 2: 2 ratio by the "International Radio Consultative Committee (CCIR) 601" format. It then windowes the required size and transfers the data to a file.

The data compression code means 20 compresses the data transmitted from the preprocessing means 10 at a predetermined bit rate. Data compression in fast play (Trick Play) in a digital video cassette recorder (D-VCR) is performed by coding a fixed length coding or a direct component (DC), a low frequency region, and a low frequency region.

The sync block recorded on the tape decodes the sync block length when the head detects it at the fixed length coding, and displays the image of the corresponding part. When the coding is performed by dividing the local component (DC), the low frequency region and the high frequency region, The component and low frequency region are decoded to display the corresponding image.

RS (Reed Solomon) code means 30 adds an error correction code by two-dimensional Reed Solomon (RS) coding. The error correction code first adds outer code parity data to correct a burst error, adds a sync code and an identification code, and then adds inner code parity data to correct a random error.

The channel modulating means 40 modulates the recording data to record the data in the transmission path.

Next, the operation of the decoder 100 will be described.

The channel demodulation means 50 decodes the modulated signal picked up from the transmission path.

The RS decoding means 60 performs error correction in the order of the inner code parity data and the outer code parity data during normal play. During trick play, only the internal code of the data subblock is decoded from the data / external parity of the recognition code following the sync code, and then output as a corrected column.

The data decompression decoding means 70 converts the error-corrected data into inverse DCT (Discrete Sine Transform) to restore the luminance signal and the color difference signal.

The reverse preprocessing means 80 performs the function of the preprocessing means 10 of the encoder 90 in reverse.

FIG. 5 shows a detailed block diagram of the RS coding means 30 of FIG.

In FIG. 5, the RS encoding means 30 comprises first to third data control blocks 110, 130 and 150, an external code RS encoder 120 and an internal code RS encoder 140. In FIG.

The first data control block 110 reads compressed data and adds parity data by the external code RS encoder 120 as shown in FIG.

The second data control block 130 reads the compressed data horizontally as one unit block and adds internal code parity data.

The third data control block 150 interleaves the compressed data in sync block units for high speed reproduction.

FIG. 6 shows a detailed block diagram of the first to third data control blocks of FIG.

In FIG. 6, a first memory means 160 and a second memory means 180 having a predetermined frame storage capacity and a control means 200 for controlling the same are provided.

In the operation of the block diagram of FIG. 6, the compressed data output from the data compression encoding means 20 is written to the corresponding address of the first memory means 160 by the write signal Wirite through the demultiplexer 170. FIG.

The first memory means 160 outputs the data read by the read signal Read to the multiplexer 190. In addition, the data input to the demultiplexer 170 is recorded at the corresponding address by the write signal of the second memory unit 180.

The second memory unit 180 outputs data through the read signal and outputs the data through the multiplexer 190. In addition, data input to the demultiplexer 170 is recorded to the first memory means 160.

That is, the first memory means 160 and the second memory means 180 alternately toggle data by the read signal r and the write signal w of the control means 200 to output data.

7 shows a data format of a recording medium according to the present invention. The data format shown in FIG. 7 records data without interleaving sync blocks.

In FIG. 7, if a burst error occurs in the sync blocks 1 and 3 indicated by the triangle and the sync blocks 2 and 4 indicated by the circle, and error correction is performed by the external code parity data, error correction is performed for the two data blocks. Therefore, the outer code error correction is performed on the first data block with the sync blocks of 1 and 3 through one path, and the outer code error correction is performed on the sync blocks 2 and 4 with the other path with the second data block. Therefore, in case of error correction in the above-described manner, error correction processing efficiency is twice that of error correction in one unit block.

As described above, in the digital recording and reproducing method and apparatus, there is an effect that the external call error correction processing efficiency can be improved by distributedly coding the external call parity data on the compressed data in a plurality of data blocks.

Claims (2)

Compression and encoding of image data on the screen for bit rate reduction, and inserting a sync code and an identification code into the compressed data to form an error correction code block for error correction, and thereby recording a plurality of magnetic tapes as recording media. A digital recording and reproducing method for recording data on a track and reproducing data recorded from a magnetic tape, wherein the data is provided for each sync block in a plurality of (integer N) data blocks to form an error correction code block for error correction. A digital recording / reproducing method characterized by sequentially reading out even-numbered, odd-numbered, odd-numbered, and even-numbered columns of blocks, and sequentially encoding outer code parity data in the outer code parity data areas of the N data blocks. . A digital recording and reproducing apparatus having an encoder (90) for screen encoding image data on a magnetic tape and a decoder (100) which picks up and decodes recording data from the magnetic tape to restore original image data. The encoder (90) comprises: preprocessing means (10) for converting input image data into digital and transmitting the desired format file; Data compression encoding means (20) for compressing and encoding data; Error correction encoding means (30) for reading the compressed coded data to distribute and code outer code parity data into a plurality of data blocks, add a sync code and an identification code, and add internal code parity data; Channel modulation means (40) for modulating the data to transmit the data over a channel, the decoder (100) comprising: channel decoding means (50) for channel decoding data picked up from the magnetic tape; Error correction decoding means (60) for error correction of the channel decoded data through two-dimensional Reed-Solomon decoding; Data decompression / decoding means (70) for decompressing the error corrected and decoded data to restore image data; And a reverse preprocessing means (80) for performing the reverse function of the preprocessing means (10).