KR200151025Y1 - Device for recording and reproducing digital image - Google Patents

Abstract

A digital video recording and reproducing apparatus is disclosed. The digital video recording and reproducing apparatus includes reproducing processing means for reproducing a signal recorded on a recording medium by appropriately encoding for error correction, and correcting a reproducing signal output from the reproducing processing means, and an error occurs for an uncorrected signal. A digital video recording and reproducing apparatus comprising: error correction means for adding and outputting position information indicating a corrected position, the digital image recording and reproducing apparatus comprising: a memory for storing data output from the error correction means and position information indicating a position where an error has occurred; And a selection signal terminal for inputting a control signal indicating a control state of a reproduction speed, and when a control signal corresponding to normal reproduction and fast reproduction is input to the selection signal terminal, outputting of the reproduction processing means corrects the error. And a multiplexer which is switched to supply to the means and is switched to supply data and position information output from the storage means to the error correcting means when a control signal corresponding to reproduction at a slower speed than the normal reproduction speed is input. When the recording medium is played back at a slower speed than the normal playback speed, the apparatus repeatedly performs error correction on the data output from the playback processing means. Therefore, in the digital video recording / reproducing apparatus, only the output of the playback processing unit passes to the internal error correction decoder during high speed playback or normal playback, and the output of the memory in which the output of the external error correction decoder is stored during still playback or slow playback is internal error correction decoding. In the case of the reproduction data corresponding to the still image by inputting negatively, the data that has not been corrected in one error correction decoding process is repeatedly processed, thereby improving error correction efficiency and reducing image quality deterioration.

Description

Digital Video Recorder

1 is a block diagram of a conventional digital video recording and reproducing apparatus.

2 is a block diagram according to an embodiment of a digital video recording and reproducing apparatus according to the present invention.

FIG. 3 is a diagram for explaining a screen for error correction by the digital video recording and playback apparatus shown in FIG.

* Explanation of symbols for main parts of the drawings

11: external error correction coder 12: interleaved processing unit

13: Internal Error Correction Code 14: Record Processing

15: playback processing unit 16: multiplexer

17: internal error correction decoding unit 18: deinterleave processing unit

19: External error correction decoding unit 20, 21: First and second memory

The present invention relates to a digital projection recording and reproducing apparatus for a digital imager, and more particularly, to a digital image recording and reproducing apparatus for obtaining high-quality images by increasing error correction capability by repeatedly correcting errors during special playback such as slow or still playback. It is about.

In general, a digital video apparatus such as a digital video cassette recorder (DVCR) uses error correction encoding, decoding, and error correction to prevent deterioration of image quality caused by errors occurring during recording and playback.

In the conventional digital image recording / reproducing apparatus, as shown in FIG. 1, the horizontal portion adds information to the digital image signal flowing from the external error correcting / decoding unit 1.

Here, the digital image signal input to the external error correcting and encoding unit 1 is coupled to a signal input source and passed through an A / D conversion unit (not shown) for converting an image signal introduced from the signal input source into a digital image signal. A signal is output from a data compression unit (not shown) which compresses data output from the A / D / conversion unit using a data compression technique.

The interleave processing unit 2 arranges image data in which horizontal side information is added to the external block code from the external error correcting and encoding unit 2 from left to right and top to bottom for each field, and then the internal error correction coding unit 3 In order to add the vertical additional information, image information is read out one byte at a time from top to bottom and from left to right.

The recording processor 4 includes a modulator for modulating the output of the internal error correcting encoder 3 after adding index information ID to distinguish between the data reproduced during reproduction, and a recording amplifier for amplifying the output of the modulator. do.

The reproduction processing section 5 includes a reproduction amplifier for amplifying the signal reproduced from the recording medium, and a demodulator for demodulating the modulated data.

The internal error correction decoding unit 6 decodes the data output from the reproduction processing unit 5, corrects an error in the correction capability, and adds an error flag when an error out of the correction capability occurs. Output to (7).

The deinterleave processing section 7 reads the mixed data again by field based on the screen order.

The external error correction decoding unit 8 corrects the data output from the deinterleave processing unit 7 according to the error flag, and then outputs the error correction to the external code block again.

An image restoring unit for restoring data output from the external error correction decoding unit 8, and an error count outside the range of error correction capability is used for restoring the compressed image information and restoring the image information of all frames. The output of the government and error correction unit detects the motion coefficient, that is, the difference of the image information between the current frame and the previous frame. In the case of a moving image, a noise removing unit for mixing the image signal of the current frame and the image signal of the immediately preceding frame and outputting the image signal is further illustrated, but not illustrated.

An error correction apparatus using such a proper code is disclosed in Japanese Patent Laid-Open No. 64-30344, and the prior art for the interleaving processing unit is disclosed in Japanese Patent Laid-Open No. 2-224484.

However, the above-described error correction apparatus processes only one error correction decoding process (inner decoding and outer decoding) during reproduction.

Therefore, if the error correction is not performed in one error correction decoding process, the error correction part of the error correction function is restored by using the image information of the previous frame after restoring the compressed image information. To prevent deterioration of image quality to some extent.

On the other hand, there are a variety of playback methods such as normal playback, high speed playback, slow playback, still playback, and the like.

The most noticeable degradation of image quality due to playback error is still playback, followed by slow playback, normal playback, and fast playback.

When the image signal is recorded in a digital method, during playback of still or slow playback, data of the image to be reproduced is repeatedly reproduced as the same image data, or once reproduced data is stored in memory to be repeatedly read and processed and displayed on the screen. do.

At this time, the reproduced data must go through error correction coding, but the part that cannot be corrected will restore the image signal of the previous frame as it is during error correction. Since an image containing an error appears continuously, there was a problem in that the image quality was deteriorated and the original image quality was not obtained.

In order to overcome the above-mentioned problems, an object of the present invention is to improve the error correction capability by repeating the error correction decoding process during special playback, such as still or slow playback slower than the normal playback speed in the digital image device to obtain a high-quality image There is provided a digital video recording and reproducing apparatus.

In order to achieve the above object, the digital image recording and reproducing apparatus according to the present invention is a digital image recording and reproducing apparatus which reproduces an image signal recorded on a recording medium by appropriately encoding for error correction;

Reproducing processing means for reproducing the recording medium recorded signal;

Error correction means for error correcting a reproduction signal from said reproduction processing means and adding and outputting position information with respect to an uncorrected signal;

Storage means for storing error corrected data and position information outputted from the error correction means;

In the normal regeneration and fast battle, the output of the reproducing processing unit is supplied to the error correcting means, and in the mode of reproducing at a slower speed than the normal reproducing speed, the output of the storage means is repeatedly supplied to the error correcting means. And selecting means for supplying.

Hereinafter, with reference to the accompanying drawings will be described a preferred embodiment of a digital video recording and playback apparatus according to the present invention.

2 is a block diagram according to an embodiment of a digital video recording and reproducing apparatus according to the present invention.

According to FIG. 2, the digital video recording and reproducing apparatus according to the present invention comprises an external error correcting encoding unit 11 for adding horizontal additional information to an incoming digital image signal;

An interleaving processing unit 12 for interleaving data output from the external error correcting and encoding unit 11,

An internal error correcting and encoding unit 13 for adding vertical additional information to the data processed by the interleave processing unit 12,

A recording processing unit 14 for recording the output of the internal error correcting and encoding unit 13 to be recorded on the recording medium;

A reproduction processing unit 15 for reproducing a signal reproduced from the recording medium;

An internal error correcting and decoding unit 17 for correcting an error within an error correctable range and adding internal additional information to an error outside the correctable range;

A deinterleave processing unit 18 for deinterleaving the output of the internal error correction decoding unit 17,

If the error is not corrected by correcting an error of the data for the external code block to which the information is added from the data output from the deinterleave processing unit 18, the external error correction decoding unit 19 outputs the external additional information again. )Wow,

A first memory 20 for storing data output from the external error correction decoding unit 19,

A second memory 22 for storing external additional information read out from the external error correction decoding unit 19;

The output of the playback processing unit 15 is selected during normal playback and high speed playback, and the outputs of the first and second memories 20 and 21 are selected and supplied to the internal error correction decoding unit 17 during still playback and slow playback. It consists of the selection part 16 which becomes a multiplexer.

Next, the operation of FIG. 2 will be described with reference to FIG. 3 as follows.

According to FIG. 2, the external error correcting coder 11, the interleave processor 12, the internal error correcting coder 13, the recording processor 14, and the playback processor 15 are external errors shown in FIG. Since the operation is the same as that of the correction encoding unit or the reproduction processing unit 1-5, a description thereof will be omitted.

First, if the current mode is the high speed playback mode or the normal playback mode, if the output of the external error correcting / decoding unit 19 outputs data corresponding to the i-th frame, the i-th external additional information (aka error flag) is stored in the first memory 20. Is written).

Accordingly, the multiplexer 16 selects the first input terminals A and A 'by the control signal CON high 1 output from the system controller (not shown) to receive the reproduction signal of the reproduction processing unit 15. Output to the internal error correction decoding unit 17.

Here, the internal error correction decoding unit 17, the deinterleave processing unit 18, and the external error correction decoding unit 19 include the internal error correction decoding unit 6, the deinterleave processing unit 7, and the external device shown in FIG. The operation is the same as that of the error correction decoding unit 8.

During normal playback, the internal error correction and decryption unit 17, the deinterleave processing unit 18, and the external error correction and decryption unit 19 are all processed. do. This is because it is not necessary to perform the processes of the deinterleave processing unit 18 and the external error correction decoding unit 19 because one screen must be configured at predetermined frame intervals in the high speed competing mode.

On the other hand, in the still or slow playback mode, the output of the external error correction decoding unit 19 is stored in the first memory 20 in order to repeat the signal reproduced on the tape to undergo the error correction decoding process. After that, it is input to the internal error correction decoding unit 17 again.

That is, the control signal CON output from the system control unit becomes low when the output of the reproduction processing unit 17 becomes the i + 1th frame data, and the first memory 20 corresponds to the i-th frame. The data is read out and input to the internal error correction decoding unit 17 through the multiplexer 16. From this time, the i-th data is subjected to the error correction decoding process for the second time. You can correct errors.

That is, as shown in FIG. 3, when an error occurs, the error correction capability of the internal error correction decoding unit 17 is 2 words, and the internal error correction decoding unit 17 and the external error correction decoding unit ( Assuming 4 words of ERASURE CORRECTION, the error flag is not corrected for the entire ECC block of nxm size when one error correction decoding process is performed. It should be generated and error corrected. Where n is an internal coder and m is an external coder.

However, in the second error correction decoding process, since the internal error correction decoding unit 17 has a correction ability of 4 words, all errors are corrected.

Erasure correction refers to knowing and correcting the position of an error by an error flag in an ECC code, and correcting without knowing the position of an error is called error correction. The correction capability is twice that of an error correction method.

Therefore, in summary, the data and error flag between the multiplexer 16 and the input terminal of the multiplexer 16 and the external error correction decoder 19 between the playback processor 15 and the internal error correction decoder 17 are summarized. Memory 20 and 21 for storing the data, passing the output of the playback processor 15 to the internal error correction decoder 17 during high-speed playback or normal playback, and the external error correction decoder 19 during thrill playback or slow playback. The output of the memory (20, 21) in which the output of < RTI ID = 0.0 >) is stored < / RTI > is input by the internal error correction decoding unit 17. Uncorrected data is repeatedly processed during processing, which can increase error correction efficiency and reduce image quality deterioration.

In addition, the present invention can obtain an image tape with reduced errors by reproducing in a slow manner and re-recording one frame at a time when the tape recovers a lot of errors due to inadvertent storage or bad recorder.

As described above, the digital video recording / reproducing apparatus according to the present invention repeatedly performs the error correction / decoding process during still or slow playback, thereby improving error correction capability and reducing image quality deterioration due to playback errors.

Claims (2)

Reproducing processing means for reproducing the signal recorded on the recording medium by appropriate encoding for error correction, and positional information for error-correcting the reproducing signal output from the reproducing processing means and indicating a position where an error has occurred for an uncorrected signal. A digital video recording and reproducing apparatus, comprising: a memory for storing data output from the error correcting means and position information indicating a position where an error has occurred; And a selection signal terminal for inputting a control signal indicating a control state of a reproduction speed, and when a control signal corresponding to normal reproduction and fast reproduction is input to the selection signal terminal, outputting of the reproduction processing means corrects the error. A multiplexer which is switched to supply to the means and is switched to supply data and position information output from the storage means to the error correcting means when a control signal corresponding to reproduction at a slower speed than the normal reproduction speed is input. A digital video recording and reproducing apparatus characterized by repeatedly performing error correction on data output from the reproduction processing means when the recording medium is reproduced at a slower speed than the normal reproduction speed. The method of claim 1, wherein the multiplexer inputs a control signal corresponding to a slow playback speed until the video data of the next frame is inputted so that error correction may be repeatedly performed a plurality of times in proportion to the speed slower than the normal playback speed. And switching to supply data and position information output from said storage means to said error correction means.