KR0182438B1 - Information reproducing control method for a video compact disc - Google Patents

Abstract

The present invention reads the optical pickup according to whether header information necessary for decoding is recognized when jumping and playing the optical pickup on a video compact disc on which data is recorded by an MPEG (Motion Picture Expert Group) algorithm. An object of the present invention is to provide a method for controlling information playback of a video compact disc in which a normal playback operation is performed by controlling the position.

To this end, the present invention provides a first step of recognizing decoding header information while waiting for a predetermined time when an optical pickup moves to a specific time and plays a video compact disc, and when the header information is recognized during the predetermined time, A second step of recognizing decoding header information while automatically reproducing the optical pickup to the initial position of the current track if the header information is not recognized during the predetermined time while normal playback is performed at the position; and When the header information is recognized in the second step, the optical pickup is moved again to a specific time to perform an information reading operation so that normal playback from the position is possible, and normal playback from the specific time is possible. Done.

Description

Information playback control method of video compact disc

FIG. 1 is a diagram showing a sector layout of recording data of a video compact disc as an MPEG type information recording medium.

FIG. 2 is a diagram showing the configuration of the user data area of FIG.

3 is a diagram for explaining a method of predicting I, P, and B picture pictures according to a general MPEG method.

4 is a block diagram of an information reproduction control apparatus of a video compact disc employed in the present invention.

5 is a flowchart for explaining a method for controlling information reproduction of a video compact disc according to the present invention.

* Explanation of symbols for main parts of the drawings

10: control function setting section 12: CD microcomputer

14: servo control unit 16: spindle motor drive unit

18: spindle motor 20: optical pickup drive unit

22: optical pickup 24: RF amplifier

26: CD DSP 28: CD ROM Decoder

30: first memory 32: MPEG microcomputer

34: 2nd memory 36: MPEG audio / video decoder

38: RGB encoder 40: digital / analog converter

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling information reproduction of a video compact disc. In particular, a video compact disc in which data is recorded by an MPEG (Motion Picture Expert Group) algorithm is normal even when the information reading position is changed due to the jump of an optical pickup. An information playback control method of a video compact disc which is adapted to perform a playback operation.

Recently, an information recording medium for recording audio / video data using an MPEG (Motion Picture Expert Group) method such as a video compact disc (VCD) has attracted attention as a next generation audio / video information recording medium.

MPEG is an international standard created by experts from ISO / IEC and Joint Technical Committee (JPC) formed by international standardization bodies ISO and IEC to compress and encode digital video, which is the core technology of multimedia environment. The 12-cm-diameter compact disc allows you to watch about 74 minutes of video.

Here, the MPEG refers only to moving images in terms of the term itself, but also defines a standard for digital voice compression and a standard for a system in which a voice / video is mixed in a packetized structure.

According to such a video compact disc, a large amount of information is compressed on an appropriate amount of information by applying the MPEG algorithm to a moving picture / audio compression method, and when the information is reproduced, the MPEG algorithm is applied based on the MPEG algorithm applied during compression. By the reconstruction processing, it is possible to record / reproduce moving picture / audio information requiring a large recording area.

As shown in FIG. 1, the sector layout of the recording data of the video compact disc includes the synchronization signal data (Sync) and the header information data, the subheader indicating the attribute of the sector, the user data, and the error detection code (EDC). Consists of Here, the user data area is composed of an ISO 11172 layer composed of a plurality of packs, as shown in FIG. 2. Each pack layer includes a system clock reference (SCR), a system header, It consists of a number of packets.

In the system clock reference, the time reference point of the pack is indicated as the number of clocks, and each packet includes a packet start code, a stream recognition code, a packet length, header data, and corresponding packet data. The data includes a decoding time stamp (DTS; Decorating Time Stamp; indicated by the number of reference clocks) and a display time stamp (PTS; Presentation Time Stamp; indicated by the number of reference clocks) indicating the decoding time. have.

In the video compact disc player for playing the recorded video compact disc as described above, the MPEG decoder is configured to decode the packet data based on the control data (for example, SCR, DTS, PTS, etc.).

Meanwhile, the MPEG video data recorded on the video compact disc (VCD) is referred to as an I picture (Intra Picture), a P picture (Predicted Picture), and a B picture (Bi-directional predicted Picture) as shown in FIG. Since the I picture has the same basic encoded picture (GOP), the I picture is the same as the compression encoding of a still picture, and is a reference picture when compression of an arbitrary picture is performed. In other words, when DPCM (Differental PCM) encoding, the first reference screen must be present. This is an I picture.

In addition, the P picture means a prediction picture, and as shown in FIG. 3, the P picture is predicted to be closest to the original picture from the previously created I and P pictures.

Lastly, although the B picture is a prediction picture, as shown in FIG. 3, the B picture is not predicted only in the previous I and P pictures, but the picture is predicted in the subsequent I and P pictures in the reverse direction. It is a rather complicated screen that makes a screen that averages (forward direction, backward direction) and then selects the most predicted screen among the three screens.

For example, when playing a video compact disc in which one piece of movie data is recorded having such a data format, the playback operation is based on a video sequence consisting of one sequence header, one or more GOPs, and a sequence end code. The decoding header contains the sequence header necessary to decode the video data and the GOP header which recognizes the start code of the GOP, not always in the middle of the data stream. In the worst case, the decoding header information is recorded only at the beginning of each disc. Can be. In this case, when the optical pickup is jumped and played from the middle of the track, video may not be played.

Accordingly, the present invention has been made in view of the above-described circumstances, and an object thereof is to decode the optical compact by jumping a specific time to a video compact disc on which data is recorded by an MPEG (Motion Picture Expert Group) algorithm. An information playback control method of a video compact disc is provided in which a normal playback operation is performed by controlling a current reading position of an optical pickup according to whether necessary header information is recognized.

According to a preferred embodiment of the present invention to achieve the above object, a first step of recognizing the header information for decoding while waiting for a predetermined time when the optical pickup to the video compact disc moving to a specific time, and; If the header information is recognized during the predetermined time, normal playback is performed at the position. If the header information is not recognized during the predetermined time, the optical pickup is automatically moved to the initial position of the current track, and the decoding header information is waited for a predetermined time. And a third step of recognizing the information, and if the header information is recognized in the second step, the optical pickup is moved again to a specific time to perform an information reading operation to enable normal reproduction from the position. A method of controlling information reproduction of a video compact disc is provided.

According to the embodiment of the present invention as described above, if the decoding header information is not recognized for a predetermined time when the video compact disc is played at a specific time, the optical pickup is moved to the initial position of the current track to recognize the decoding header information. Since information is read again by moving to a specific time, normal playback is performed from that specific time.

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

4 is a block diagram of an information reproduction control apparatus for a video compact disc employed in the present invention. The embodiment of the present invention is a control function setting unit 10, CD-microcomputer 12, servo control unit 14, spindle. Motor driver 16, spindle motor 18, optical pickup driver 20, optical pickup 22, RF amplifier 24, CD-DSP 26, CD-ROM decoder 28, first memory 30, the MPEG microcomputer 32, the second memory 34, the MPEG audio / video decoder 36, the RGB encoder 38, and the digital / analog converter 40.

In the figure, the control function setting unit 10 is provided with a plurality of operation command keys to selectively input a function assigned to the optical disc reproducing apparatus.

The CD-microcom 12 performs spindle servo, focusing / tracking servo, and information reproduction processing for information reproduction on the optical disc D as an information recording medium based on the function or mode set by the control function setting section 10. FIG. Perform overall control of the function.

The servo controller 14 servo-controls the spindle motor 18 which drives the optical disc D at constant speed through the spindle motor driver 16 in response to the servo control of the CD-microcomputer 12. The pick-up driving unit 20 is used to control the focusing / tracking servo of the optical pickup 22 as the laser information reading means.

The spindle motor driver 16 drives the spindle motor 18 to control the servo controller 14.

The RF amplifier 24 amplifies the RF signal read from the optical disc D by the optical pickup 22.

The CD-DSP 26 performs digital processing on the RF signal amplified by the RF amplifier 24. When the optical disc is a CD or CDG, the CD-DSP 26 performs digital processing. Subsequently, subsequent processing is performed by the CD / CDG processing means (not shown) to enable playback.

The CD-ROM decoder 28 decodes the data output from the CD-DSP 26, extracts the data in sectors, and outputs the MPEG data and the control data separately.

Here, the CD-ROM decoder 28 searches for the video header sequencer start code (00 00 01 B3) and the GOP start code (00 00 01 B8) by 4 bytes of data from an internal bitstream data buffer. It will recognize the GOP header.

The first memory 30 is allocated as a work area of the CD-ROM decoder 28 to store data, and the first memory 30 is made of, for example, an SRAM.

The MPEG-microcom 32 receives control data output from the CD-ROM decoder 28 by interaction with the CD-microcom 12, and then describes an MPEG audio / video decoder based on the control data. A control signal for the decoding operation at 36 is outputted.

The second memory 34 is allocated to the MPEG microcomputer 32 as a work area during video / audio processing, while time information (e.g., time according to track tracking required for information reproduction operation on the optical disc D) is provided. : Minute: second) is stored, and the second memory 34 is made of, for example, SRAM.

The MPEG audio / video decoder 36 decodes the MPEG data output from the CD-ROM decoder 28 in accordance with a video sync clock and an audio sync clock.

In the MPEG audio / video decoder 36, the MPEG video decoder can recognize the video sequence header and the GOP header based on the MPEG data from the CD-ROM decoder 28.

The RGB encoder 38 converts the video signal or text signal decoded by the MPEG audio / video decoder 36 into a composite video signal having color signals of R, G, and B, and outputs the converted video signals.

The digital / analog converter (DAC) 40 converts the digital audio data output from the MPEG audio / video decoder 36 into an analog type audio signal and outputs the converted audio signal.

According to the general playback operation of the video compact disc player configured as described above, when the play button on the control function setting unit 10 is first turned on, the CD-microcom 12 controls the servo circuit unit 14, and the servo circuit unit Under the control of (14), the spindle motor driver 16 rotates the spindle motor 18 at constant speed, and then the optical pickup 22 via the optical pickup driver 20 is controlled under the control of the servo circuit unit 14. According to the MPEG algorithm, data on a video CD on which predetermined data is recorded is read out.

The read data are amplified by the RF amplifier 24, signal-processed in the form of a serial data stream by the CD-DSP 26, and separated into MPEG data and control data by the CD-ROM decoder 28, respectively. Since it is applied to the MPEG-microcomputer 32 and the MPEG audio / video decoder 36, the MPEG audio / video decoder 36 controls the MPEG-ROM decoder 28 from the CD-ROM decoder 28 under the control of the MPEG-microcomputer 32. The data is decoded according to the video synchronous clock and the audio synchronous clock and output to the video signal and the digital audio data, respectively. The output video signal is added to the R, G, and B color signals by the RGB encoder 38 and displayed on the video display device (e.g., CRT) as a composite video signal, while the output digital audio data is converted into a digital / analog converter. At 40, the signal is converted into an analog audio signal and then output through an audio output device (eg, a speaker).

Next, the method for controlling information reproduction of a video compact disc according to the present invention will be described based on the flowchart of FIG. 5 based on the apparatus configured as described above.

Once the optical pickup 22 is jumped to a certain specific time to be reproduced (step 50), the optical pickup 22 is decoded while waiting (step 52) at the position for a predetermined time (for example, about 10 seconds). Header information (ie, header information for the sequence header start code and the GOP start code) is recognized. Accordingly, if the header information for decoding is output from the CD-ROM decoder 28 or the MPEG video decoder within a predetermined time (YES in step 54), the CD-microcom 12 based on the signal from the MPEG-microcom 32 While the normal playback operation at the current position is controlled, the CD-ROM decoder 28 or the MPEG video decoder does not output the decoding header information despite the predetermined time elapsed (NO in step 54). The MPEG microcomputer 32 applies a signal indicating that the decoding header information has not been read to the CD microcomputer 12. Accordingly, the CD-microcom 12 controls the servo control unit 14 to move the optical pickup 22 to the initial position of the current track (step 56), and the position for a predetermined time (for example, about 3 seconds). In step (58), the decoding header information is recognized. In this way, if the decoding header information existing at the initial position of the track is recognized (YES in step 60), the CD-microcomputer 12 attempts to reproduce the optical pickup 22 by controlling the servo controller 14. The position is shifted to a specific time (step 62). Thereafter, the optical pickup 22 reads out information at the specific time, and the read out information includes the CD-DSP 26, the CD-ROM decoder 28, the MPEG audio / video decoder 36, and the like. Playback is normally performed (step 64).

According to the present invention as described above, if the decoding header information is not recognized for a certain time when playing the video compact disc at a specific time by jumping the optical pickup, the optical pickup is automatically moved to the initial position of the current track and then decoded. The header information is recognized and information is read at a specific time on the basis of the recognized decoding header information.

Claims (1)

A first step of recognizing decoding header information while waiting for a predetermined time when the optical pickup moves to a specific time and plays the video compact disc; and if the header information is recognized during the predetermined time, normal playback at that position is performed. In the second step, if the header information is not recognized during the predetermined time, the optical pickup is automatically moved to the initial position of the current track, and the decoding header information is recognized while waiting for a predetermined time. And a third step of moving the optical pickup to a specific time when information is recognized to perform an information reading operation to enable normal playback from the position.