KR19980030588A - How to detect start time of CD track of video compact disc player - Google Patents

Abstract

The present invention relates to a CDDA track start time detection method of a video compact disc player.

To this end, the present invention first determines the version of the loaded disc, and if the disc version is 2.0, the number of MPEGAV tracks recorded on the disc by reading the 11th and 12th bytes of the ENTRIES.VCD file. Detect and store. The CDDA track is read by detecting the maximum MPEGAV track number by reading 4 bytes of data of the last entry and reading the first byte of the entry, and detecting whether there is a track '1' larger than the maximum MPEGAV number by referring to the TOC data. Detect if it exists. Through this process, if a track '1' larger than the maximum MPEGAV number is detected, the track number is set to the minimum CDDA track number, and the PMIN, PSEC, and PFRAME data of the start time of the track are read out by referring to the TOC data again. After that set the save time to memory as the start time of the CDDA track.

Accordingly, the present invention can easily confirm the existence of a CDDA track that can be recorded on a disc of a Video CD 2.0, and detect and store the start time when a CDDA track exists, thereby making it convenient for later playback of the CDDA track. It has the effect of providing sex.

Description

How to detect start time of CD track of video compact disc player

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video compact disc player, and more particularly, to a video compact disc that detects the start time of a CDD track in which only audio data is recorded on a version 2.0 disc of the video compact disc. D.D.A track start time detection method.

With the development of audio and video media, optical disc players for recording and reproducing video and audio data on semi-permanent optical discs have been developed.

Such an optical disc player reproduces an image and / or audio recorded on an optical disc and outputs it through a screen and / or a speaker, and has a higher signal-to-noise ratio than conventional image and / or audio reproducing apparatus, resulting in better image quality and / or Or, it can reproduce signals with sound quality, generate no noise due to irregular reproduction and modulation, very low distortion, no ghost, random access, etc. There is a trend.

In addition, such an optical disk player includes a compact disk player (CDP), a laser disk player (LDP), a compact disk graphic player (CDGP), and a video compact disk player (VCDP: video compact disk player, hereinafter abbreviated as video CD player, has been developed and widely used. Also, recently, a digital video disk (DVD) using MPEG-2 video compression technology and A digital video disc player has been developed that can play and record several gigabytes (GB) of data, including moving images, on a 12 cm optical disc such as a current CD, and can also play current CDs and VCDs. It is designed to be compatible.

On the other hand, there are two types of discs used in the video CD player, version 1.1 and version 2.0. Among the discs of the dual version 2.0, audio as well as a general MPEGAV track in which video data and audio data are simultaneously recorded are recorded. CDDA tracks in which only data is recorded may be present in the track after the MPEGAV track in some cases. In the past, when a video CD player is to be played with a version 2.0 disc, the existence of such a CDDA track and the start time of the CDDA track are determined. There was no easy way to detect it.

Therefore, the present invention has been proposed in view of the above-described conventional points of view, and an object of the present invention is to detect the presence or absence of a CDDA track on a disc played in a video CD player and to detect the start time of the CDDA track in the presence of the CDDA track. A video CD player's CDDA track start time detection method is provided.

According to a preferred embodiment of the present invention for achieving this object, a CD of a video compact disc player for detecting the presence of a CDDA track from a disc loaded for playback in a video compact disc player and a start time of the CDDA track. A track start time detection method comprising the steps of: (a) reading and storing TOC (table of content) data of the loaded disc and files in a VCD directory and determining whether the disc is a version 2.0 disc; (B) If the disc version is 2.0 in the step (a), read the Entries Used data in the ENTRIES.VCD file among the files in the stored VCD directory, and store the number of entries used. Read the 4-byte data of the first byte of the last entry to indicate the MPEGAV track number. Setting the maximum MPEGAV track number, (c) determining whether there is a track that is greater than '1' than the maximum MPEGAV track number set in the step (b) by referring to the stored TOC data; If there is a track that is larger than '1' than the maximum MPEGAV track number set in step (c), the number of tracks having a value larger than '1' than the maximum MPEGAV track number is set as the minimum CDDA track and the TOC data is referred to for the minimum CDDA. Reading out the PMIN, PSEC, and PFRAME data corresponding to the track and storing and setting it as a start time of the CDDA track.

1 is a schematic block diagram of a typical video compact disc player for practicing the present invention.

2 is a detailed flowchart of a C.D.D.A track start time detection method of a video compact disc player according to a preferred embodiment of the present invention.

Fig. 3 shows the structure of an entry. VCD file.

* Description of the symbols for the main parts of the drawings *

10: pick-up and actuator unit 20: RF signal amplification and servo signal processing unit

30: motor drive unit 40: key input unit

50: microcomputer 60: digital signal processing part

70: MPEG decoder 80: Audio signal processor

90: video signal processing unit 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 disc player for practicing the present invention.

As shown in FIG. 1, an optical disc player for implementing the present invention includes a pickup and actuator unit 10, an RF (radio frequency) signal amplification and servo signal processing unit 20, 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 executes an optical pickup from a disc loaded in a disc tray (not shown) and outputs an RF signal which is read accordingly.

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

The RF signal amplification and servo signal processing unit 20 amplifies an RF signal provided from the pickup and actuator unit 10 and provides a servo control signal according to the signal to the motor driving unit so that the focus servo and the tracking servo can be performed.

The digital signal processing unit 60 digitally processes the amplified RF signal provided from the RF signal amplification and servo signal processing unit 20, performs error detection and error correction, and outputs the result to the MPEG decoder 70.

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. .

The audio signal processor 80 and the video signal processor 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. ) And the screen 110 are displayed as an audio transmission and an image, respectively.

Meanwhile, according to the present invention, when a predetermined disc is loaded in the disc tray, the microcomputer 50 reads disc contents information (TOC) and files in the VCD directory from the loaded disc, thereby internal memory (not shown). To store at first, the version of the loaded disc is determined from the 9th and 10th data of the ENTRIES.VCD file, which contains a list of starting points of the MPEGAV tracks on the read disc.

If the determined version of the disc is 2.0, the microcomputer 50 reads the 11th and 12th bytes of the ENTRIES.VCD file to detect and store the number of used entries, that is, the number of MPEGAV tracks recorded on the disc. do.

Further, the microcomputer 50 detects the maximum MPEGAV track number by reading the 4-byte data of the last entry and reading the first byte of the first entry. When the number of the maximum MPEGAV track is detected, the microcomputer 50 refers to the TOC data to determine the maximum MPEGAV number. It is detected whether there is a track larger than '1'.

At this time, if there is a track '1' larger than the maximum MPEGAV number, the microcomputer 50 sets the track number to the minimum CDDA track number, and again refers to the TOC data to indicate PMIN, PSEC, After reading the PFRAME data, set it to memory as the start time of the CDDA track.

FIG. 2 is a detailed flowchart of a CDD track start time detection method of a video CD player according to a preferred embodiment of the present invention, and FIG. 3 shows the structure of an ENTRIES.VCD file in a VCD directory. Drawing.

In step S20, the TOC (table of content) data of the loaded disk and the files in the VCD directory are read and stored, and in step S22, the data of the ENTRIES.VCD file among the files in the read-stored VCD directory is referred to. To determine if the loaded disk is a version 2.0 disk. That is, as shown in Fig. 3, the version of the disk can be determined from the ninth and tenth bytes. If the disk loaded in step S12 is not a version 2.0 disk, the flow is terminated. Proceed to).

Proceeding from step S22 to step S24, step S24 is an entry used data which is the 11th and 12th data of the ENTRIES.VCD file as shown in Fig. 3 of the files in the VCD directory stored in step S20. The number of entries (Entry) used, that is, the number of MPEGAV tracks recorded on the disc is detected and stored, and the flow advances to step S26.

Then, in step S26, the 4-byte data of the last entry is read from the ENTRIES.VCD file, and the flow advances to step S28.

Thereafter, in step S28, the first byte indicating the number of MPEGAV tracks among the four bytes of the last entry in step S26 is set as the maximum MPEGAV track number, and in step S30, the TOC data stored in step S20. If there is a track larger than '1' than the maximum MPEGAV track number set in step S28 with reference to FIG. The flow ends if there is no CDDA track otherwise.

Finally, if the process proceeds from step S30 to step S32, in step S32, the number of tracks having a value greater than '1' greater than the maximum MPEGAV track number set in step S28 is set as the minimum CDDA track, and again the TOC data After reading PMIN, PSEC, and PFRAME data corresponding to the minimum CDDA track, save as the start time of the CDDA track is set, and the flow ends.

As described above, the present invention can easily confirm the existence of a CDDA track that can be recorded on a disc of a Video CD 2.0, and also detect and store the start time of the CDDA track if it exists, and then It has the effect of providing convenience in reproduction.

Claims (1)

In the C.D.D. track start time detection method of a video compact disc player for detecting the presence of a CDDA track and the start time of a CDDA track from a disc loaded for playback on a video compact disc player, (A) reading and storing table of content (TOC) data of the loaded disk and files in a VCD directory and determining whether the disk is a version 2.0 disk; (B) In step (a), if the disk version is 2.0, the number of entries used is stored by reading Entries Used data of the ENTRIES.VCD file among the files in the stored VCD directory, and storing the number of entries. Reading 4-byte data to set a first byte representing the number of MPEGAV tracks among the four bytes of the last entry as the maximum MPEGAV track number; (C) referring to the stored TOC data to determine whether there is a track that is greater than '1' than the maximum MPEGAV track number set in step (b); (D) If there is a track that is larger than '1' than the maximum MPEGAV track number set in step (C), set the number of tracks '1' larger than the maximum MPEGAV track number as the minimum CDDA track and refer to the TOC data. And reading out the PMIN, PSEC, and PFRAME data corresponding to the minimum CDDA track and storing and setting them as the start time of the CDDA track.