KR0161779B1 - Method of detecting start position of cd-da track in video compact disc - Google Patents

Abstract

The present invention accurately detects / stores an initial track number for a start position of a CD-DA track using information of ENTRIES.VCD of a video CD information area existing in a program area of a video compact disc (version 2.0) capable of playing a video. It is to provide a method for detecting the start position of a CD-DA track in a video compact disc, which enables to quickly control information of a CD-DA track.

To this end, the present invention includes a first step of reading and storing information of a TOC area and a VCD directory in a program area of a video compact disc (version 2.0), and detecting the number of exits used; And a second step of calculating the track number of the start position of the CD-DA track after reading the information of the last entry based on the detected number of used entries.

Description

How to detect CD-DA track starting position in video compact disc

1 is a schematic diagram for explaining a track structure of a video compact disc as a general interactive information recording medium.

FIG. 2 is a schematic diagram illustrating a directory structure as the interactive information recording medium shown in FIG.

FIG. 3 is a diagram schematically showing the track / directory structure of the video compact disc shown in FIG. 1 and FIG. 2 in a physical position based on absolute time.

4 is a diagram showing a layout of an ENTRIES.VCD file existing in a video CD information area of a video compact disc (version 2.0) employed in the present invention.

FIG. 5 is a diagram showing the layout of an entry field in the ENTRIES.VCD file shown in FIG.

6 is a view showing an example of a general TOC area employed in the present invention.

7 is a block diagram of a video compact disc player according to the present invention.

8 is a flowchart for explaining a method for detecting a CD-DA track start position in a video compact disc according to the present invention.

* Explanation of symbols for main parts of the drawings

10: controllable setting unit 12: 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 audio / video decoder

34: second memory 36: CDG decoder

38: third memory 40: video DAC

42: RGB encoder 44: Audio DAC

The present invention relates to a method for detecting a CD-DA track starting position in a video compact disc. In particular, the start position of a CD-DA track using information of an ENTRIES.VCD file existing in a program area of a video compact disc (version 2.0). The present invention relates to a method for detecting a CD-DA track starting position in a video compact disc, which is configured to accurately detect.

As is well known, a compact disc graphics (CDG) disc having a still picture and a voice recorded from a compact disc containing high quality audio information has been proposed, and solves the monotony of image expression in the still picture of the CDG disc. A video compact disc (Video CD), which records video information and audio information, has also been developed.

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

In addition, in recent years, users can apply information recording / playback of video CDs to not only information recording media known as CD-i disks configured to reproduce information on character shapes, music, etc. in an interactive manner, but also interactive information recording media. It is a state proposed in the form of a so-called interactive video CD (Video CD Ver 2.0) configured to selectively reproduce information specific to an interactive method based on the MPEG algorithm. Here, according to the interactive information recording medium, a plurality of sub-directories branching from the main directory for displaying an overall menu of contents recorded on the information recording medium are included, and for each sub-directory, display items for outputting the screen. (Play Items) and a number of Segment Items defined in the Display Items are provided, and when the user designates sequentially from the main directory to the Segment Items, the corresponding screen is displayed to provide necessary information. You can take it.

As shown in FIG. 1, a plurality of tracks exist in the program area of a video CD as a general interactive information recording medium. The first track (Track 1) is assigned to a video CD data track. From the second track, the N-1 track is allocated to the MPEG audio / video track, and the last N track is selectively assigned to the CD-DA track. Here, the first track has a PVD (Primary Volume Descriptor) defined at position (00:02:16), and at position (00:03:00), the KARINFO. A maximum of 63 encoded text files (KARINFO.CC) (Basic Information Header) and Variable Length (variable length) are defined (see FIG. 3).

FIG. 2 shows the directory structure of the interactive information recording medium shown in FIG. 1. According to the directory structure, the VCD directory in which files in the video CD information area are located with respect to the root directory (0) is shown in FIG. MPEGAV directory where all files representing MPEG audio / video tracks are located, CDDA directory where all files representing CD-DA (Compact Disc-Digital Audio) audio tracks are located, and segment display area on the information recording medium (Segment Play). If the area is set, the SEGMENT directory including the files in the area is included. If the Karaoke Basic Information Area is set on the information recording medium, the KARAOKE directory is located. CD-I files such as the CD-I application and the EXT directory where extended PSD (Play Sequence Descriptor) files are located. And containing the CDI directory, directories typically required for the video CD as an information recording medium is a re-route direct and CDI directory, directories and VCD MPEGAV directory.

In the VCD directory, the disc information area (INFO.VCD) and the registration table area (ENTRIES.VCD; 00:04) from the position (00 (minutes): 04 (seconds): 00 (frames) on the information recording medium. : 01), List ID Offset Table (LOT.VCD; 00: 04: 02-00: 04: 33) and Screen Play Sequence Descriptor Area (PSD.VCD; 00: 04: 34- (00:07:64 [max 256 sectors]).

Next, referring to FIG. 3, which shows the track / directory structure of the video CD applied as an interactive information recording medium in a separate position based on absolute time, the files of the VCD directory (INFO.VCD, ENTRIES.VCD, LOT.VCD). , PSD.VCD), and the first segment of the data structure corresponding to the menu of the segment display item (see FIGS. 1 and 2) of the SEGMENT directory subsequent to the VCD directory, that is, position (00:05:00). Display Item (Segment Play Item # 1 = Play Item # 1000; Menu 1), and Second Segment Display Item (Segment Play Item # 2 = Play Item # 1001; Menu 2), Position 3rd segment display item (Segment Play Item # 3 = Play Item # 1002; Menu 3) of (00:09:00) and 23rd segment display item (Segment Play Item # 23) of position (00:49:00) Play Item # 1022; menu 3) is assigned, followed by the Nth track (track 8 in FIG. 3) from the second track (track 2) containing the moving picture information.

In order to perform a specific function such as direct time search or slow motion in a playback device that plays such a video compact disc, the data currently being played is MPEG data, CDG data, or CDDA data. After determining whether the data is MPEG, it is classified into an MPEG decoder in case of MPEG data, a CDG decoder in case of CDG data, and an audio DAC in case of CDDA data, and the playback commands (for example, play, scan, slow, In the case of video compact disc 2.0, MPEGAV track, CDDA, and CDG track are mixed in the program area so that MPEG decoding operation, CDG decoding operation or CDDA data processing operation can be quickly and easily performed. To do this, it is necessary to control MPEG decoding, CDG decoding, and pure audio data separately. In other words, as shown in Figs. 1 to 3, the CD-DA track immediately follows the MPEG audio / video track, so if the starting position is not known correctly when moving to the CDDA data area during MPEG decoding, Playback is not performed.

Accordingly, the present invention has been made in view of the above circumstances, and an object thereof is to provide a CD-DA using information of ENTRIES.VCD of a video CD information area existing in a program area of a video compact disc (version 2.0) capable of playing a moving picture. The present invention provides a method for detecting a CD-DA track start position on a video compact disc, by which information track of a CD-DA track can be quickly detected by accurately detecting and storing an initial track number of a track start position.

In order to achieve the above object, according to a preferred embodiment of the present invention, the information of the VCD directory in the TOC area and the program area of the video compact disc (version 2.0) is read and stored and the number of used entries is detected. A first step; A CD-DA track in a video compact disc comprising a second step of reading information of the last entry based on the number of used used entries and calculating and storing a track number for the start position of the CD-DA track. A starting position detection method is provided.

The number of entries used is recorded in the 11th to 12th bytes of ENTRIES.VCD.

Further, the track number for the start position of the CD-DA track is obtained by the information +1 of the first byte of the last entry.

According to the embodiment of the present invention configured as described above, the information on the number of entries used in ENTRIES.VCD in the stored VCD directory after reading and storing the information of the VCD directory in the TOC area and the program area of the video compact disc (version 2.0) The information is detected, the last entry is read, and the signal having the information +1 of the first byte in the last entry is stored as the track number for the start position of the CD-DA track.

Hereinafter, a CD-DA track starting position detection method in a video compact disc according to the present invention will be described in more detail with reference to the accompanying drawings.

FIG. 4 is a diagram showing the layout of the ETRIES.VCD file (see FIG. 2 or FIG. 3) existing in the video CD information area of the video compact disc (version 2.0) employed in the present invention. A VCD file contains a number of list of start positions in the MPEG audio / video track on the disc. The ENTRIES.VCD file is fixed to a single sector size and as shown in Figure 3 above. It is located at (00:04:01).

In the case of such a layout of ENTRIES.VCD files, the first to eighth byte positions are coded to indicate that they are ENTRYVCD as a field for file identification, and the subsequent nineth to tenth byte positions are specified. The field for the Version Number indicates the version number of the video CD contents used on the disc in the same way as the field contents of the Details Version Number of the INFO.VCD file. The information about the total number of entries used as the fields for Entries Used is encoded in binary information. The minimum value of the Entries Used field is 1 and the maximum value is 500. Subsequent byte positions (13 + 16 ^* (N-1)-16 + 4 ^* (N-1)) in units of 4 bytes are information for each entry as an entry field. Is listed.

The layout of the entry field is composed of a track number field and an entry address field as shown in FIG. 5. In the track number field, the entry address is located. Information on the track number of a track is shown, and the entry address field contains a sector address encoded in mm: ss: ff of the entry point. Is encoded as a BCD code at byte position M + 2, and the ff value is encoded as a BCD code at byte position M + 3.

By this form, the first entry (Entry) is entry number 1 and is located in byte position 13. The fields of entries that are not used are filled with $ 00, which is a hexadecimal value, and the unused entries are present after the last used entry. The entries are encoded in increasing order of the entry addresses, and the list of entries is as if all the start positions of the MPEG audio / video track were encoded (i.e. the absolute time for each track was encoded in the TOC area). ; See also Figure 6).

7 is a block diagram of a video compact disc player to which the present invention is applied. The apparatus to which the present invention is applied includes a control function setting unit 10, a microcomputer 12, a servo control unit 14, and a spindle motor driving unit. 16, spindle motor 18, optical pickup driver 920, optical pickup 22, RF amplifier 24, CD-DSP 26, CD-ROM decoder 28, first memory 30 MPEG audio / video decoder 32, second memory 34, CDG decoder 36, third memory 38, video DAC 42, RGB encoder 42, and audio DAC 44. .

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 microcomputer 12 performs spindle servo and focusing to reproduce information on a video compact disc (version 2.0 in the present invention: D) as an information recording medium based on the function or mode set by the control function setting unit 10. MPEG audio / video decoder 32, which not only performs overall function control of tracking / serving servo and information reproduction processing, but also receives control data output from a CD-ROM decoder 28 to be described later, based on the control data. And while controlling the operation of the CDG decoder 36, the track number for the start position of the CD-DA track assumed in the present invention is calculated and stored when the video compact disc D is played.

The servo controller 14 servo-controls the spindle motor 18 which drives the video compact disc D at constant speed through the spindle motor driver 16 in response to the servo control of the 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 under the control of the servo controller 14.

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

A CD-DSP 26 processes the RF signal amplified by the RF amplifier 24 into a serial data stream.

The CD-ROM decoder 28 descrambles the data output from the CD-DSP 26 in 8-bit units, extracts them in sector units, and separates and outputs MPEG data and control data. In addition, the CD-ROM decoder 28 may decode CDG and CDDA data from data output from the CD-DSP 26.

The first memory 30 is temporarily allocated as a work area of the CD-ROM decoder 28 and temporarily stores data descrambled in the CD-ROM decoder 28. It consists of SRAM.

The MPEG audio / video decoder 32 adjusts the MPEG data output from the CD-ROM decoder 28 by the control signal (ie, the chip selecting signal) of the microcomputer 12 to the video sync clock and the audio sync clock. Decode and output

The second memory 34 is usually made of DRAM and is allocated as a work area of the MPEG audio / video decoder 32. The second memory 34 includes a video compact disc (version 2.0) assumed in the present invention. As the information of the TOC area is read out by the optical pickup 22 during the initial playback, information in the TOC area (for example, information about the absolute time (mm (minute): ff (frame)), etc. of each track), etc.) is stored. In addition, information of the VCD directory in the first track corresponding to the video CD data track is stored, and information on the start position of the detected CD-DA track (ie, track number) is stored. The information about the start position of the detected CD-DA track may be stored in the third memory 38 to be described later.

The CDG decoder 36 transmits CDG and CDDA data output from the CD-ROM decoder 28 to the video synchronization clock and / or the audio clock synchronizer by a control signal (ie, a chip selecting signal) of the microcomputer 12. Decode accordingly.

The third memory 38 is allocated as a work area of the CDG decoder 36, and is typically made of SRAM.

The video DAC 40 converts the digital video data provided from the MPEG audio / video decoder 32 or the CDG decoder 36 into analog.

The RGB encoder 42 converts the video signal analog converted by the video DAC 40 into a composite video signal having color signals of R, G, and B, and outputs the converted video signal.

The audio DAC 44 converts the digital audio data provided from the MPEG audio / video decoder 32 or the CDG decoder 36 into an analog audio signal and outputs the audio signal.

Next, a method of detecting a CD-DA track start position in a video compact disc according to the present invention will be described with reference to the flowchart of FIG. 8 based on the apparatus configured as described above.

Once the play command is input from the control function setting unit 10, the microcomputer 12 controls the servo controller 14 to operate the spindle motor driver 16 and the optical pickup driver 20 to operate the optical pickup 22. Information recorded in the TOC area on the video compact disc (version 2.0 in the embodiment of the present invention) can be read. Subsequently, the read TOC information (for example, information about an absolute time (mm): ss (second): ff (frame)) of each track, etc.) is stored in the second memory 34, and then the optical pickup ( 22) the program area is entered and information is read in the first track (step 80). Then, based on the information in the read first track, it is judged whether or not the currently loaded disc is Video CD 2.0. The determination operation is usually performed in the INFO.VCD file or ENTRIES.VCD file in the video CD information area. Decoding the signal encoded in the Specification Version Number field will tell you the version of the disc currently loaded.

If the disc currently loaded is Video CD 2.0 (YES in step 82) by such a judgment operation, the entry used by reading the contents recorded in the 11th and 12th bytes of ENTRIES.VCD in the VCD directory ( The number of entries is detected (step 84). Then, the last entry is read using the number of used entries, and the last entry needs to read 4 bytes from the {4 * (ENTRIES-USED-1) +13} th byte in the ENTRIES.VCD. (Step 86). In other words, a plurality of entries exist in ENTRIES.VCD, and since the entries are set in sizes of 13 bytes to 4 bytes, 4 from {4 * (ENTRIES-USED-1) +13} bytes. By reading the bytes, you can see the location of the last entry in the MPEG audio / video track.

Then, 1 is added to the information of the first byte of the last entry (i.e., the last track number of the MPEG audio / video track) (step 88) to the second memory 34 as the start track number of the CD-DA track. Save (step 90). This is because the initial track of the CD-DA track is located after the last track of the MPEG audio / video track.

As described above, according to the present invention, since the information on the start number of the CD-DA track which is present after the MPEG audio / video track is accurately detected and stored, the MPEG decoding or CDDA data processing operation can be performed quickly. .

Claims (3)

A first step of reading and storing information in the TOC area and the VCD directory in the program area of the video compact disc (version 2.0) and detecting the number of entries used; And reading out the information of the last entry based on the detected number of used entries and calculating and storing the track number of the start position of the CD-DA track in the video compact disc. CD-DA track starting position detection method. The method of claim 1, wherein the number of used entries is recorded in 11th to 12th bytes of ENTRIES.VCD. 2. The method of claim 1, wherein the track number for the start position of the CD-DA track is obtained by information + 1 of the first byte of the last entry.