KR0132816B1 - Driving method of video-cd player - Google Patents

Abstract

There is disclosed a method of operating a MPEG type video CD disc player which can make a piecewise operation at a normal reproducing speed. The video data stored in the CD disc is read at a normal reproducing speed. Only an intra-frame is reproduced among the video frames of the read video data, and the reproduced intra-frame is repeatedly output until the next intra-frame.

Description

How to operate Video CD disc player

1A and 1B show the sector structure of the VEDEO-CD.

2 shows the track configuration of the VEDEO-CD.

3 shows the structure of the first track of the program area of the VEDEO-CD disc.

4 is a diagram showing the configuration of the INFO.VCD file shown in FIG.

5 is a diagram showing the configuration of the ENTRIES.VCD file shown in FIG.

6 shows an interpolation method of MPEG1.

7 is a diagram showing that MPEG video and audio sectors are interleaved.

8 is a diagram showing an example of the configuration of an MPEG data area.

FIG. 9A shows a typical MPEG video sector, and FIG. 9B shows a typical MPEG audio sector.

10A and 10B illustrate an MPEG video sector and an MPEG audio sector including a system header.

11 is a block diagram showing the configuration of a general VEDEO-CD player.

12 is a flowchart showing a method of driving a VEDEO-CD disc player according to the present invention.

The present invention relates to a method of playing a video CD disc player, and more particularly, to a driving method that implements a division operation in which a screen is reproduced at a normal speed but only an intra frame is stopped.

VEDEO-CD is a system that plays back full-motion images combined with audio using the Compact Disc format. The system uses the International Standard Organization's Moving Picture Experts Group (MPEG) standard to compress video and audio information, resulting in high quality audio combined full screen and full notion. ) It is an image.

One VEDEO-CD disc may contain 74 minutes of high quality audio and video programs compressed according to the MPEG1 standard.

The VEDEO-CD format is based on the CD bridge disc format. The CD Bridge CD-I format is a slightly modified format used by CD-ROMXA. By using the CD bridge disc concept, a VEDEO-CD disc can be played on a CD-I, CD-ROM XA, VEDEO-CD player, or the like.

VEDEO-CD discs meet the CD Bridge specification. VEDEO-CD can record 650M BYTE data by freely combining sound, video and computer data.

VEDEO-CD records and plays back video and audio data compressed according to MPEG standards. In addition to the motion compensation DPCM algorithm for increasing the data compression rate, the MPEG standard provides a special interpolation method for implementing random access functions that a user needs to find and provide a desired part of the storage medium at that time.

The feature of the interpolation method used in the MPEG standard is to periodically insert an independently reconstructable reference frame so that it can be recovered in any frame, and insert a reconstructible frame only by referring to the reference frame between the reference frames.

Since the reference frame can be independently reproduced in any part of the VEDEO-CD, the content of the disc can be quickly searched by selectively reproducing it.

Due to the nature of VEDEO-CD, the disc should rotate at a constant speed. This is called a constant linear velocity (Constant Linear Veloctiy) method, the prescribed value is equal to 1.2 ~ 1.4 [m / S] for the CD player.

The high-speed search operation in the CLV method is performed by moving the pickup apparatus between tracks formed concentrically on the disk to access an arbitrary point.

In some cases, it is necessary to reproduce recorded video data and audio data at a normal speed, but to display the screen in a stationary state for each scene so that the screen can be observed in detail.

For example, in high-speed search, approaching near a destination requires searching in more detail but excluding unnecessary parts.

SUMMARY OF THE INVENTION An object of the present invention is to provide a driving method for implementing a segmentation operation of displaying video data and audio data recorded on a disc at a normal speed in a VEDEO-CD disc player and displaying only an intra picture in a stationary state.

According to another aspect of the present invention, there is provided a method of driving a VEDEO-CD disc player, the method including: reading video and audio data recorded on a disc in a normal playback mode; Selecting and reproducing only an intra frame among various frames included in the read video data, and repeatedly outputting the reproduced intra frame by an interval of time between intra frames. Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1A and 1B show the sector structure of the VEDEO-CD, and FIG. 1A shows the sector structure of Form 1, and FIG. 1B shows the sector structure of Form 2. FIG. Each of the VEDEO-CD sectors is 2352BYTE, and includes SYNC information, a header, and a subheader, followed by data.

The header has a sector address, expressed as (minutes: seconds), relative to the beginning of the track. The mode is also displayed but is 1 or 2 for VEDEO-CD.

The subheader consists of data types (audio, video, program-related data, etc.), forms (1 or 2), trigger bits (END OF RECORD and END OF FILE), and coding information.

The sector structure of VEDEO-CD has two types, namely, product 1 and product 2, similar to CD-I, CD-ROM, and XA (CD-ROM Extended Architecture). Form 1 is used for accommodating computer data, and Form 2 is used for accommodating compressed audio video / pictures. As shown in FIGS. 1A and 1B, Form 1 and Form 2 are distinguished through sub-headers. Form 2 has no third EDC / ECC, so it can accommodate more data than Form 2.

2 shows the track configuration of the VEDEO-CD. The VEDEO-CD has a lead-in area 20, a program area 22, and a lead-out area 24 similarly to compact discs such as CD-DA, CD-ROM, CD-I and the like.

The lead-in area 20 and the lead-out area 24 are encoded into a CD-ROM XA data track including sectors of mode 2 form 2 having no contents. In the subcodes of all sectors of the lead-in area 20 and the lead-out area 24, the file number, channel number, submode and coding information are all defined as zero.

The program area 22 may have up to 99 tricks 201... 299 numbered from 1 to 99. Although the VEDEO-CD can have a CD-DA track, the initial track must be a special VEDEO-CD data track. At the same time, the CD-DA track must be located after the VEDEO-CD data track. Each track should be at least 4 seconds long.

Each track must have a pose (PAUSE: 300), a front margin (FRONT MARGIN: 302), an MPEG data area 303, and a rear margin (REAR MARGIN: 312). Pause 300 must be at least 150 sectors (2 seconds since 1 sector is 1/75 seconds), front margin 302 must be at least 15 sectors (typically 30 sectors), and rear margin 312 should be at least It should be at least 15 sectors (typically 45 sectors).

3 is a diagram showing the structure of the first track of the program area of the VEDEO-CD disc, wherein the number on the left is an address indicating the start position of each file. In FIG. 3, PVD 304 is optional and used in CD-I and defines the location and size of the PATH TABLE. The karaoke basic information area 306 is also optional.

VEDEO-CD information area 310 is VEDEO-CD This is where the general information of the disc is stored. It starts at address 04: 00 and contains files of INFO.VCD and ENTRIES.VCD.

The INFO.VCD file has the VEDEO-CD system identification information and is a zero sector size file starting at 00:40:00.

ENTRIES.VCD is a one-sector size file starting at 00:40:01 with each track's start address.

4 is a diagram showing the configuration of the INFO.VCD file shown in FIG. In the subhead of the V CD file, the file number is 0, the channel number is 0, the sub mode is binary 100 1001, and the coding information is defined as 0.

5 is a diagram showing the configuration of the ENTRIES.VCD file shown in FIG. In the subhead of the ENT RIES.VCD file, the file number is 0, the channel number is 0, the sub mode is binary 10001001, and the coding information is 0.

VEDEO-CD records and plays back video and audio data compressed according to the MPEG standard ISO 11172 (hereinafter referred to as MPEG11). One pack of the MPEG1 stream is recorded in one sector of MPEG VIDEO or AUDIO.

The MPEG1 standard consists of three parts: MPEG-system, which defines a method of multiplexing and synchronizing video and audio data, and MPEG-audio, which defines a compression algorithm of video data, and MPEG-audio, which defines a compression algorithm of video data.

While MPEG-Video's screen size and frame rate are basically free, MPEG recommends 352 × 240 CIF (Common Image Format) at 30 frames per second. CIF is a progressive scan of 360 × 240, which is half of that of the digital TV's CCIR 601 format, that is, 720 × 240 interlaced scan.

MPEG video compression algorithm is a motion compensation DPCM that combines motion compensation, DCT, and quantization methods. The motion compensation DPCM algorithm has recently been in the spotlight as a digital method of HDTV because of its superior compression performance and universality.

In addition to the motion compensation DPCM algorithm for increasing the data compression rate, MPEG uses a special interpolation method to implement a random access function that a user needs to find and provide a desired part of the storage medium at that time.

6 shows an interpolation method of MPEG1. MPEG1 periodically inserts a reference frame so that it can be recovered in any frame. This reference frame is called an I picture, and the I picture is encoded in a manner similar to intra cod-ing, that is, a JPEG of a still picture. P-pictures and B-pictures are located between the I picture and the next I-picture. P-pictures are frames that are predicted by using the same information as motion pictures from I-pictures, and B-pictures are different from P-pictures. Otherwise, it is a picture created by making a prediction frame by interpolation between a previous I picture or a P picture and the above P picture, and then DCT encoding the remaining difference by DPCM with the frame.

Of course, when interpolating, it does not simply interpolate, but interpolates after finding and compensating for movement. Also, instead of always interpolating, the method with the smallest error is applied by performing all the blocks inside, front and rear prediction, and bidirectional interpolation in 16 × 16 blocks.

This B picture has two advantages instead of a large amount of computational complexity. First, if only P picture is connected, fsat forward function cannot be supported, but B picture is inserted between them, so if only P picture is restored except this, fast forward is increased several times. Secondly, bidirectional interpolation is more efficient than predictive coding, and thus the image quality is improved because excellent compression performance can be obtained.

In a stereo music program, it is recorded in the left audio channel MPEG audio channel 0 and in the right audio channel MPEG audio channel 1.

MPEG video and MPEG audio sectors are interleaved in the same way as in MPEG video and audio system targer decoders as defined in the system part of the MPEG standard to ensure that no overflow or underflow occurs. Should be given.

7 is a diagram showing that MPEG video and audio sectors are interleaved. In the MPEG data area as shown in FIG. 2, the first MPEG video sector and the first MPEG audio sector should have an MPEG system header. The first sector in the MPEG data area must be an MPEG video sector or MPEG audio sector containing the MPEG system header.

8 is a diagram showing an example of the configuration of an MPEG data area. In FIG. 8, the sector denoted by E denotes an empty sector of the front margin, the sector denoted by Vsy denotes an MPEG video section not including the MPEG system header, and the sector denoted by ASY denotes an MPEG system header. A sector denoted by MPEG represents an MPEG video sector, and a sector denoted by V denotes an MPEG audio sector including an MPEG system header, and a sector denoted by A denotes an MPEG audio sector that does not include an MPEG system header.

One MPEG sector may have one MPEG PACK or may have an ISO_11172 end code. Each MPEG PACK has either audio packets or video packets.

9A shows a typical MPEG video sector, and FIG. 8B shows a typical MPEG audio sector. In FIGS. 8A and 8B, PACK START has a size of 4 bytes as a fax tart code and a value of hexadecimal 000001A.

SCR is a system clock reference code and has a size of 5 bytes. MUX RATE has a size of 3 bytes.

The pack data of the MPEG video sector has 2312 bytes. The pack data of the MPEG audio sector occupies 2292 bytes and has a zero field of 20 bytes.

As shown in FIG. 8, the first MPEG video sector and MPEG audio sector of the track must have a system head. The system header has 15 bytes, which reduces the length of the pack data.

10A and 10B illustrate an MPEG video sector and an MPEG audio sector including a system head.

11 is a block diagram showing the configuration of the VEDEO-CD player. In FIG. 11, reference numeral 110 is a VEDEO-CD disc, 112 is a pickup device, 114 is a digital signal processor (hereinafter referred to as a DSP), 116 is a CD-ROM decoder, and 118 is a microcomputer. A processor, 120 is a host processor, 122 is a video decoder, and 128 is an audio decoder.

The pickup device 112 reads the digital information recorded in the form of pit and outputs it as an analog signal. The DSP 114 receives an analog signal output from the pickup device 112, and reproduces and outputs digital data therefrom.

The CD-ROM decoder 116 buffers the input data into a built-in RAM (not shown), and decodes the data under the control of the host processor 120 to provide it to the host processor 120. The CD-ROM decoder 116 decodes sectoral data as shown in Figs. 1A and 1B to decode sectoral data as shown in Figs. Pack data as shown in FIG. 9B is output.

The microprocessor 118 receives a user's operation command through a control panel (not shown) and drives the disk according to the user's operation command, or generates and provides data to the host processor 120.

The host processor 120 controls the CD-ROM decoder 118, the video decoder 122, the audio decoder 128, and the like according to data related to an operation command from the microprocessor 118.

The host processor 120 inspects the data input through the CD-ROM decoder 116 and in the case of normal data, separates the video data and the audio data and outputs them to the video decoder 122 and the audio decoder 128, respectively. do. The host processor 120 receives the pack unit video data and the audio data from the CD-ROM decoder 116, and separates them into packet units and outputs them to the video decoder 122 and the audio decoder 128, respectively.

The video decoder 122 decodes data according to the MPEG1 format to form data of 8 bits each of R, G, and B. The decoded digital RGB data is converted into an analog RGB signal by the RGB digital / analog converter 124, input to the RGB encoder 126, and then converted into a composite video signal and output.

The audio decoder 128 decodes the data according to the MPEG1 format. The digital audio data output from the audio decoder 128 is converted into an analog audio signal by the audio digital / analog converter 130 and passes through the low pass filter 132 to reduce noise generated during the D / A conversion process. And then output.

The driving method of the VEDEO-CD player according to the present invention will be described in detail with the block diagram shown in FIG.

12 is a flowchart showing a method of driving a VEDEO-CD disc player according to the present invention. First, the microprocessor 118 receives a drive operation command, scans the disc in accordance with normal playback speed, and reads out recorded data. The read data is provided to the CD-ROM decoder 116.

The CD-ROM decoder decodes the read data and drills the video data packet and the audio data packet to the host processor 120 (step 122).

The host processor 120 provides the audio data packet to the audio decoder 128 and the video data packet to the video decoder 122 among the data packets recorded from the CD-ROM decoder 116.

At this time, the packet header information is read out of the video data packet, and only the video data packet having an intra frame screen is provided to the video decoder 122 (step 122).

The video decoder 122 receives a video data packet provided from the host processor 120, decodes the video data packet, and reproduces the intra frame image data. The reproduced intra frame image data is stored in a frame buffer memory (not shown) inside the video decoder 122.

The intra frame image data stored in the frame buffer memory is repeatedly read by the time interval (about 0.7 seconds) between the intra frame screens, and the intra frame image based on the read intra frame image data is reproduced and output. The axial force of the VEDEO-CD is an image signal having a constant scanning speed such as NTS C, PAL, etc. Thus, by repeating scanning each frame of the frame sequence several times, a division operation showing still images for each scene can be achieved.

As described above, the driving method of the VEDEO-CD disc player according to the present invention has the effect of achieving the division operation by decoding and playing only the intra frame image data among the video data read out by the normal reproduction operation.

Claims (2)

A drive method of a video CD (VEDEO-CD) disc player for reproducing video CD discs recorded with MPEG standard compressed image data, the method comprising: reading video data recorded on a disc in a normal playback mode; A method of driving a video CD disc player, the method comprising: selecting and reproducing only an intra frame among various frames included in the read video data and repeatedly outputting the reproduced intra frame by a time interval between intra frames. The method of claim 1, wherein the audio data recorded with the video data is reproduced at a normal playback speed.