KR19980030587A - 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 in the case of version 2.0 of the disc, detects the maximum MPEGAV track number by reading and referring to each of the 4 bytes from the 13th byte of the ENTRIES.VCD file, When the number of the maximum MPEGAV track is detected, the presence of the CDDA track is detected by determining whether there is a track '1' larger than the maximum MPEGAV number by referring to the TOC data. If there is a track that is '1' larger than the maximum MPEGAV number, the track number is set to the minimum CDDA track number, and after referring to the TOC data, PMIN, PSEC, and PFRAME data for the start time of the track are read, and CDDA is read. Set Save to Memory as the track's start time.

Therefore, 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 player that detects a start time of a CDDA 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 playback 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 moving picture compression technology and playback thereof are used. A digital video disc player has been developed, which can record and play back gigabytes (GB) of data including moving images in 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 of the optical disc player, version 1.1 and version 2.0. In the dual version 2.0 discs, audio data as well as general MPEGAV tracks in which video data and audio data are simultaneously recorded are recorded. CDDA tracks that are only recorded may be present in the track after the MOEGAV track in some cases, and conventionally, when playing a disc of version 2.0 on a video CD player, it is easy to determine the existence of such a CDDA track and the start time of the CDDA track. There was no detectable method.

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 and the start time of a CDDA track from a loaded disc for playback in a video compact disc player. A track start time detection method comprising the steps of: (a) reading and storing table of content (TOC) 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 step (a), set the maximum MPEGAV track number of the MPEGAV track in which video and audio data is recorded to 1, and ENTRIES of files in the VCD directory read and stored in step (a). Setting an entry-read-pointer in the 13th byte of the .VCD file, and (c) step 13 in step (b) above Determining whether the first byte representing the track number of the MPEGAV track is '0' by reading four bytes from the byte; and (d) if the first byte is not '0' in the step (c), the first byte is Determining whether it is greater than the set maximum MPEGAV track number and setting the first byte to the maximum MPEGAV track number, increasing the position of the entry-read-pointer by 4 bytes, and returning to step (c); E) determining, if the first byte is '0' in the step (c), referring to the TOC data to determine whether there is a track larger than the set maximum MPEGAV track number, and (f) the step (d). If the first byte is not larger than the maximum MPEGAV track number in step or if the track '1' is larger than the set maximum MPEGAV track number in step (c) Setting a number of tracks larger than '1' to the maximum MPEGAV track number as a minimum CDDA track, reading PMIN, PSEC, and PFRAME data corresponding to the minimum CDDA track, and storing the same as the start time of the CDDA track. do.

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.track start time detection method of a video compact disc player according to a preferred embodiment of the present invention.

3 is a diagram showing the structure of an entry VCD file;

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

10: pickup 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 unit

70: MPEG decoder 80: audio signal processing unit

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. ), A microcomputer 50, a digital signal processor 60, an MPEG decoder 70, an audio signal processor 80, a video signal processor 90, a speaker 100, and a screen 110.

The pickup and actuator unit 10 performs 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 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 another servo control signal to the motor driving unit to perform the focus servo and the tracking servo.

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.

On the other hand, according to the present invention, when a predetermined disc is loaded in the disc tray, the microcomputer 50 reads the disc contents information (TOC) and files in the VCD directory from the loaded disc, thereby internal memory (not shown). In particular, the version of the disc loaded with the ninth and tenth bytes of the ENTRIES.VCD file containing the list of starting points of the MPEGAV tracks on the read disc is determined.

If the determined disc version is 2.0, the microcomputer 50 detects the maximum MPEGAV track number by reading the first track representing the track number of the MPEGAV track by reading 4 bytes from the 13th byte of the ENTRIES.VCD file. When the number of the MPEGAV track is detected, the TOC data is detected to detect whether there is a track '1' larger than the maximum MPEGAV number. In this case, if there is a track '1' larger than the maximum MPEGAV number, the microcomputer 50 determines the track number. Set the minimum CDDA track number, read the PMIN, PSEC, and PFRAME data for the start time of the track with reference to the TOC data, and save it in memory as the start time of the CDDA track.

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

In step S10, the table of content (TOC) data of the loaded disk and the files in the VCD directory are read and stored. Then, in step S12, the data of the ENTRIES.VCD file among the files in the read-stored VCD directory is stored. Refer to this to determine whether 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).

On the other hand, in step S14, the maximum MPEGAV track number of the MPEGAV track on which video and audio data is recorded is set to 1 and an entry is made in the 13th byte of the ENTRIES.VCD file among the files in the VCD directory read and stored in step S10. After setting the read-pointer, the process proceeds to step S16, in which the 13th byte indicates information about the actual entry, that is, the MPEGAV track.

In step S16, four bytes are read from the 13th byte of the ENTRIES.VCD file, and in step S18, the first byte representing the track number of the MPEGAV track among the four bytes of data read in step S16 is' Determine if 0 '. If it is read in step S18, if the first byte of the four bytes is '0', the process proceeds to step S26; otherwise, the process proceeds to step S20.

In step S18, if the process proceeds to step S20, in step S20, it is determined whether the first byte read out is larger than the maximum MPEGAV track number set in step S14 or step S22 described later. If not, proceed to step S28. If proceeding from step S20 to step S22, in step S22, the first byte is set to the maximum MPEGAV track number, and then step S24 is performed. After increasing the position of the entry-read-pointer by 4 bytes, the flow returns to step S16 to perform the flow again.

If the first byte is '0' in step S18, it is determined whether there is a track that is greater than '1' than the maximum MPEGAV track number set with reference to the TOC data. If there is a track having a large value of '1', the flow advances to step S28; otherwise, the flow ends because no MPEGAV track exists.

On the other hand, if there is a track in which the first byte is not larger than the maximum MPEGAV track number in step S20 or '1' is larger than the maximum MPEGAV track number set in step S26, and the process proceeds to step S28, in step S28 Set the track corresponding to the track number '1' larger than the maximum MPEGAV track number as the minimum CDDA track, and when step S28 is completed, in step S30, referring to TOC data, the minimum set in step S28 After the PMIN, PSEC, and PFRSME data corresponding to the CDDA track are read, and the data is set to the start time of the CDDA track, 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 loaded disc for playback in 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) If the disc version is 2.0 in step (a), set the maximum MPEGAV track number of the MPEGAV track in which video and audio data is recorded to 1, and ENTRIES of files in the VCD directory read and stored in step (a). Setting an entry-read-pointer in the 13th byte of the .VCD file; (C) reading four bytes from the thirteenth byte in step (b) to determine whether the first byte representing the track number of the MPEGAV track is '0'; (D) In step (c), if the first byte is not '0', it is determined whether the first byte is larger than the set maximum MPEGAV track number, and if the first byte is large, the first byte is set to the maximum MPEGAV track number and the entry-reading is performed. Increasing the position of the pointer by 4 bytes and returning to step (c) above; (E) if the first byte is '0' in the step (c), referring to the TOC data, determining whether a track larger than the set maximum MPEGAV track number exists; (F) if the first byte is not greater than the maximum MPEGAV track number in step (d) or if there is a track that is '1' greater than the maximum MPEGAV track number set in step (c), then the value is greater than the maximum MPEGAV track number. And setting the number of this large track as the minimum CDDA track, reading out the PMIN, PSEC, and PFRAME data corresponding to the minimum CDDA track and setting the storage as the start time of the CDDA track. D.D.A track start time detection method.