KR19990041940A - How to compensate for lost data in optical disk systems - Google Patents

Abstract

The present invention relates to a method of compensating for lost data in an optical disc system, the method comprising: (a) loading a disc, reading table of contents (TOC) data, and waiting for a key input; And (c) determining whether a C2 error signal is detected from the playback signal when the playback is performed, counting the number of occurrences of the C2 error signal when the C2 error signal is detected, and comparing the counted number with a preset reference value. And (d) determining whether the GFS signal is 'low' or 'high' when the number of occurrences of the C2 error signal counted in step (d) (c) is greater than the reference value; E) If the GFS signal is 'high' in (D), reset the number of occurrences of the counted C2 error signal and return to (C), and (F) In (D), When in the 'low' state, the audio scene Mute the output of the video signal, and outputting the normal frame screen signal before the error occurrence and detecting whether the C2 error signal is generated again within a predetermined time after the step (e). Outputting a video signal to be reproduced, and unmuting the audio signal to perform normal reproduction.

Description

How to compensate for lost data in optical disk systems

The present invention relates to a method for reproducing an optical disc system, and more particularly, to loss of an optical disc system for partially correcting a loss of data even when an unrecoverable error occurs due to the contamination or damage of the disc in performing the reproduction in the optical disc system. It relates to a data correction method.

With the development of audio and video media, optical disk systems for recording and reproducing video and audio data on semi-permanent optical disks have been developed and used. Such optical disk systems reproduce video and / or audio recorded on optical disks. Output through the screen and / or speaker, the signal to noise ratio is higher than that of conventional video and / or audio playback devices can reproduce the signal with better image quality and / or sound quality, noise caused by irregular playback and modulation There are many advantages such as no distortion, very little distortion, no ghost, and random access.

Such optical disk systems also include compact disk players (CDPs), laser disk players (LDPs), compact disk graphic players (CDGPs), and video compact disk players (VCDPs). video compact disk player) has been developed and widely used. Also, a digital video disk (DVD) using MPEG-2 moving picture compression technology and a digital video disk player for playing it have been developed and spread. It is possible to record and play back gigabytes (GB) of data including moving pictures in an optical disc of 12 cm, such as a current CD, and to make it possible to play back current CDs and VCDs.

On the other hand, the optical disc used in the optical disc system as described above has a low error rate because its life is semi-permanent, and since the audio and video data recorded on the optical disc are recorded in a digital manner, external or internal When a predetermined error occurs due to the cause, it is configured to detect and restore the original signal.

That is, as described above, the conventional optical disk system is configured to detect the occurrence of an error in accordance with the state of the GFS signal generated when the recorded data is reproduced and to recover the generated error.

However, in spite of the above-described configuration, when the disk is severely damaged due to the contamination or scratch of the disk, there is a problem that the reliability of restoring the error data is only lost by detecting the GFS signal.

Accordingly, the present invention has been made to solve such a problem in the related art, and an object of the present invention is to provide an optical disc system that partially compensates for the loss of data even when an unrecoverable error occurs due to contamination or damage of the disc during playback. To provide a method for compensating loss data.

According to a preferred embodiment of the present invention for achieving the above object, in the optical disk system, the loss data correction method for detecting the occurrence of an error when the playback function is executed and correcting it when an unrecoverable error occurs, A) loading a disc and reading TOC (table of contents) data and waiting for key input; (b) executing playback when a playback key signal is input; and (c) playing if the playback is performed. Determining whether a C2 error signal is detected from the signal, and counting the number of occurrences of the C2 error signal when the C2 error signal is detected, comparing the counted number with a preset reference value; and (d) the counting step in step (c). Determining whether the GFS signal is 'low' or 'high' when the number of occurrences of the generated C2 error signal is greater than the reference value And (e) resetting the number of occurrences of the counted C2 error signal if the GFS signal is 'high' in step (d) and returning to step (c); (D) muting the output of the audio signal when the GFS signal is 'low', and outputting the normal frame picture signal before an error occurs, and (e) the ( D) detecting whether the C2 error signal is generated again within a predetermined time after the step; outputting a video signal to be reproduced if it is not generated, and releasing the mute of the audio signal to perform normal playback.

1 is a schematic block diagram of a general optical disc system for practicing the present invention;

2A and 2B are detailed flowcharts showing a method for correcting loss data of an optical disk system according to a preferred embodiment of the present invention.

<Description of the code | symbol about the principal part of drawing>

10: pickup and actuator unit 20: RF signal amplification and servo signal processing unit

30: motor and motor drive unit 40: key input unit

50: microcomputer 60: digital signal processing unit

70: MPEG decoder 75: RAM

80: audio signal processor 90: video signal processor

100: speaker 110: screen

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

1 is a schematic block diagram of an optical disk system for practicing the present invention.

As shown in FIG. 1, an optical disc system for implementing the present invention includes a pickup and actuator unit 10, an RF (radio frequency) signal amplification and servo signal processor 20, a motor and a motor driver 30, and a key input unit. 40, the microcomputer 50, the digital signal processor 60, the MPEG decoder 70, the audio signal processor 80, the video signal processor 90, the speaker 100, and the screen 110.

The pickup and actuator unit 10 performs an optical pickup from a disc loaded in a disc tray (not shown), and outputs the RF signal read out to the RF signal amplification and servo signal processing unit 20 accordingly.

In addition, the motor and the motor driving unit 30 drive the spindle motor (not shown) to rotate the disk and drive the actuator unit 10 so that the pickup unit 10 performs optical pickup to read data recorded on the disk. To output as an RF signal.

The RF signal amplification and servo signal processing unit 20 amplifies the RF signal provided from the pickup and actuator unit 10 and provides a servo control signal according to the signal to the motor and the motor driving unit 30 to provide the focus servo and the tracking servo. To be done.

The digital signal processing unit 60 performs digital signal processing on the amplified RF signal provided from the RF signal amplification and servo signal processing unit 20, performs error detection and error correction, and then converts the digital signal processed playback signal into an MPEG decoder ( 70) and provides the microcomputer 50 with the GFS signal and the C2 error signal according to the error detection and error correction.

The MPEG decoder 70 decodes an error corrected digital video signal and an audio signal provided from the digital signal processor 60 based on the MPEG compression format and outputs the decoded video signal to the video signal processor 90 and the audio signal processor 80. In this case, the decoded video signal is addressed to the memory 75, that is, the RAM 75, and is sequentially output to the video signal processor 90 while being stored in one frame, that is, one screen unit.

The audio signal processing unit 80 and the video signal processing unit 90 process the decoded audio and video signals provided from the MPEG decoder 70 and output them to the speaker 100 and the screen 110, respectively. 100) and the screen 110 are respectively displayed as an audio transmission and an image.

In addition, the key input unit 40 generates an input signal for executing a predetermined function, and provides a function key signal desired by the user to the microcomputer 50, and the microcomputer 50 is provided from the key input unit 40. The control signal according to the key signal is generated to execute the input function, and the respective constituent members are controlled so that the function in the execution state can be performed smoothly.

On the other hand, according to the present invention, the microcomputer 50 detects whether the C2 error signal according to the error correction is provided from the output signal of the digital signal processor 60, and detects the built-in counter (not shown) when the C2 error signal is detected. Counts the number of times the C2 error signal is continuously detected, and compares the counted number with a preset reference value, in which case the counted number of continuously detected C2 error signals is less than or equal to the preset reference value. It resets the detection frequency of the received C2 error signal and determines whether the C2 error signal is detected again. If the C2 error signal is larger than the reference value, the state of the GFS signal provided from the digital signal processor 60 is 'low' or 'high'. If it is determined that the status of the GFS signal is 'low', it is determined that an unrecoverable error signal has occurred in the playback signal, and the control signal accordingly It occurs. That is, when the number of times C2 error signal is detected is greater than the reference value and the state of the GFS signal is 'low', the microcomputer 50 generates a control signal to the MPEG decoder 70 so that the MPEG decoder 70 may access the RAM 75. The frame signal stored before the error is read and output to the video signal processor 90, and the audio signal processor 80 generates a control signal to mute the audio signal output.

That is, the microcomputer 50 detects an error signal generation from the reproduction signal, and if an error signal that cannot be restored from the reproduction signal is detected, the microcomputer 50 controls the MPEG decoder 70 and the audio signal processing unit 80 so that the video signal is a frame before the error generation. The signal is output so that the normal screen is displayed and the audio signal is muted.

On the other hand, after that, the microcomputer 50 continuously determines whether a C2 error signal is detected. At this time, if a C2 error signal is not detected for a predetermined time, a video signal is generated and reproduced by generating a control signal to the MPEG decoder 70. At the same time, by generating a control signal to the audio signal processing unit 80 at the same time to release the audio mute so that the normal reproduction audio signal is output, and repeats this process until the end of reproduction.

2A and 2B are detailed flowcharts illustrating a loss data correction method of an optical disk system according to a preferred embodiment of the present invention.

In step S10, when the disc is loaded in the disc tray (not shown), the microcomputer 50 recognizes this, and then in step S20, a control signal is generated by the pickup and actuator unit 10 to lead-in. After the TOC data recorded in the deduction is reproduced, the reproduced TOC data is stored in an internal memory (not shown), and then in step S30, the mode is set to a key input standby state to execute key input for executing a predetermined function. Wait

Thereafter, in step S40, if a reproduction key signal is provided through the key input unit 40, the process proceeds to step S50, in which the microcomputer 50 amplifies the motor, the motor driving unit 30, and the RF signal amplification. And control signals are generated by the servo signal processing unit 20 or the like to perform regeneration.

As described above, if playback is performed in step S50, in step S60, the microcomputer 50 detects a C2 error signal in the playback signal, and if it is determined that a C2 error signal is generated in step S60, that is, When the C2 error signal is provided from the digital signal processing unit 60, in step S80, the number of detections of the C2 error signal generated continuously is counted, and the flow advances to step S90.

Then, in step S90, the microcomputer 50 compares the detected number of detected C2 error signals, that is, the number of occurrences of the C2 error signal with a preset reference value, wherein the number of occurrences of the counted C2 error signal is preset If less than or equal to the reference value, the process returns to step S70, and if greater, the process proceeds to step S100.

When the process proceeds from step S90 to step S100, in step S100, the microcomputer 50 determines the state of the GFS signal provided from the digital signal processing unit 60. In step S100, the state of the GFS signal is determined. If 'high', the flow proceeds to step S105 to reset the number of occurrences of the counted C2 error signal, and then returns to step S60. If the GFS signal is 'low', the error signal generated from the playback signal cannot be restored. Recognize and proceed to step S100.

Then, in step S110, the microcomputer 50 generates a control signal to the MPEG decoder 70 so that the MPEG decoder 70 blocks the output of the video signal currently being reproduced and stored in the RAM 75. To output a video signal for, and at the same time generates a control signal to the audio signal processing unit 80 to mute the output of the audio signal.

Thereafter, in step S120, the microcomputer 50 determines whether the C2 error signal is detected again within a predetermined time, and if the C2 error signal is detected again within the predetermined time, the microcomputer 50 detects the previous normal frame in step S110. If the C2 error signal is not detected again within a predetermined time while maintaining the video output and audio mute state, in step S130, a control signal is generated to the MPEG decoder 70 to stop the output of the video signal for the previous frame and It outputs a video signal to be reproduced, and generates a control signal to the audio signal processing unit 80 to release the audio mute so that the reproduced audio signal is normally output.

In addition, after that, it is determined whether playback is completed in step S140, and when playback is completed, the driving of the optical disc system is stopped and the flow ends in step S150, and if playback is not completed, the flow proceeds to step S60. To repeat the flow.

As described above, the present invention can increase reliability because the C2 error signal as well as the GFS signal is used to detect an error signal during reproduction in the optical disc system, and the video signal is generated when an unrecoverable error signal occurs. By replacing the previous normal frame screen and muting the audio signal, it is possible to partially correct the video and audio noise according to the error signal, thereby enabling the user to watch the video and audio reproduced without discomfort even when an error occurs.

Claims (1)

A method for correcting loss data of an optical disk system for detecting an occurrence of an error when executing a playback function in an optical disk system and correcting an error when an unrecoverable error occurs, (A) loading a disk and reading table of contents (TOC) data and waiting for key input; (B) executing playback when a playback key signal is input; (C) determining whether a C2 error signal is detected from the reproduction signal when the reproduction is performed, counting the number of occurrences of the C2 error signal when the C2 error signal is detected, and comparing the counted number with a preset reference value; (D) determining whether the GFS signal is 'low' or 'high' when the number of occurrences of the counted C2 error signal is greater than the reference value in step (c); (E) resetting the number of occurrences of the counted C2 error signal when the GFS signal is 'high' in step (d) and returning to step (c); (F) muting the output of the audio signal when the GFS signal is 'low' in the step (d), and outputting the normal frame picture signal before the error occurs; (E) detecting whether the C2 error signal is generated again within a predetermined time after the step (d), outputting a video signal to be reproduced if it does not occur, and releasing the mute of the audio signal to perform normal reproduction. How to compensate for lost data on disk systems.