KR19980017222A - How to scan an image of a DVD system - Google Patents

Abstract

A disc scanning method of a DVD system, comprising: image data being compressed in a file area, and a disc having image information corresponding to I-frames among the image data in a disc information file (F0) area. CLAIMS 1. A disk scanning method of a DVD system which performs playback; A first step of storing position information of image data corresponding to the I-frame; When switching to the disc scan mode during the normal playback mode of the DVD system, the image corresponding to the I-frame closest to the current playback position is referred to by referring to the position of the image data corresponding to the I-frame stored in the first step. A second step of reproducing image data corresponding to an I-frame at a position closest to the current reproduction position with reference to the positions of the data; After the second step, with reference to the positions of the image data corresponding to the I-frame stored in the first step, the I-frame of the corresponding recording position is jumped at a predetermined interval with respect to the image data corresponding to the I-frame. And a third step of reproducing the image data corresponding thereto.

Description

How to scan an image of a DVD system

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image scanning method for scanning an image using positional information of an image corresponding to an I-frame stored in a disc information file area in a digital video disc (hereinafter referred to as DVD) system. .

The basic technology of optical discs for noncontact reading using laser light has long been established. Since then, the spread of reproduction-only devices including LD (Laser Disc) and CD (Compact Disc) has been spread to general homes, and the recording and reproducing apparatus of additional recording type and rewriting type has been put into practical use. Also, in recent years, high speed / overwrite has been progressing to a higher density, which is typically represented by the development of a short wavelength laser or a recording / reproducing technology.

On the other hand, in the digital image compression technology, the compression method using the image information before and after the time has been put into practical use in the manner that the compression process is performed only within one TV screen. In particular, the compression method called MPEG2 can obtain a picture quality of the level that is currently received in a general home at an information rate of 10Mbps or less.

Accordingly, digital moving picture disc media represented by DVDs have emerged and play a part in the role of VTRs as conventional image files along with VDRs (recordable types) which are expected to appear in the future.

The disk of such a DVD has a capacity of about 4.7 Gbit and can record one movie on one disk. In particular, the disk information is included in the disk information file area.

This will be described in detail with reference to FIG. 1.

As shown in Fig. 1, a DVD disc generally consists of a read in area A, a system area B, a volume managment area C, and a plurality of files F0 to F99. It consists of a file area C and a read out area E. FIG. At this time, files 1 (F1) to 99 (F99) of the file area D substantially contain a movie, a music video, or the like. At this time, the movie or music video of the files 1 (F1) to 99 (F99) is compressed by a moving picture compression standard called MPEG2 as described above. MPEG is a high-combination standard for various image coding technologies. The hybrid coding scheme combining motion compensation DPCM (differential pulse coding), two-dimensional discrete cosine transform (DCT), quantization of DCT coefficients, variable-length coding (VLC), etc. Basically used.

Motion Compensation DPCM determines the motion of an object between the current frame and the previous frame and predicts the frame according to the object's movement to produce a differential signal representing the difference between the current frame and the predicted value. for Hybrid Predictive / Transform Coding ”, IEEE Transactions on Communication, COM-33, NO.12 (December 1985).

The two-dimensional DCT also reduces or eliminates spatial redundancy between the image data by converting one block of digital image data, for example, a block of 8 * 8 pixels into a group of change coefficient data. This two-dimensional DCT technique is described in Chen and Pratt's "Scene Adaptive Coder", IEEE Transaction on Communication, COM-32, No. 3 (March 1984), and the quantizer and zigzag scanning of the transform coefficient data described above. (zigzag scanning) By processing with VLC or the like, data to be transmitted can be efficiently compressed.

Also, the motion compensation DPCM estimates the motion between the current frame and the previous frame to predict the current frame from the previous frame. The motion estimation is represented as a two-dimensional vector representing the displacement between the previous frame and the current frame.

On the other hand, the type of the picture is an I-frame to which only intraframe coding is applied according to the method of motion estimation, a P-frame predictively encoded by forward motion prediction / compensation from a previous I-frame or P-frame, and The frame is divided into B-frames that are bi-directionally compensated and predictively coded from two frames, either before or after I-frames or P-frames, and used as a reference for predicting and encoding other frames, that is, I-frame and P-frame. It is called a frame.

In particular, since I-frame only intra-frame encoding is applied, it can be said that the data loss for the picture is the smallest.

Therefore, conventionally, a disk scan has been performed by searching for images corresponding to these I-frames to files 1 (F1) to 99 (F99) and then decoding and outputting only the images corresponding to the I-frames.

Therefore, the conventional disk scan method has a problem in that the disk scan takes a long time by searching for an image corresponding to an I-frame while tracking tracks of the disk one by one.

Therefore, in the present invention, after detecting position data of image information corresponding to an I-frame in advance, a disk scan can be performed faster by performing a disk scan using position data of image information corresponding to the detected I-frame. It is an object of the present invention to provide a disk scanning method of a system.

According to the present invention, in order to achieve the above object, image data is compressed in a file area, and a disc information file F0 is reproduced for a disc in which the position information of image data corresponding to an I-frame among the image data is recorded. A disk scanning method of a DVD system for performing the following steps, comprising: a first step of storing position information of image data corresponding to the I-frame; When switching to the disc scan mode during the normal playback mode of the DVD system, the image corresponding to the I-frame closest to the current playback position is referred to by referring to the position of the image data corresponding to the I-frame stored in the first step. Reproducing data; After the second step, the image data corresponding to the I-frame stored in the first step is referred to, and the image data corresponding to the I-frame is jumped by a predetermined interval, corresponding to the I-frame at the corresponding position. And a third step of reproducing the image data.

1 is a schematic configuration diagram of a DVD disc

Fig. 2 is a block diagram of a DVD system for performing the disc scan method of the present invention.

Figure 3 is a detailed flowchart showing a preferred embodiment of the disk scan method of the present invention.

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

100: disc 200: DVD player

300: control unit 400: key input unit

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

In FIG. 1, file 0 (F0) of a DVD disc is also called a disc information file, and various reference information for data contained in files 1 (F1) to file 99 (F99) of a DVD disc are stored. In particular, in the disc information file F0 area, the position information of the image data corresponding to the I-frame among the image data recorded in the files 1 (F1) to (99) is stored. At this time, the positional information of the image data corresponding to the I-frame is recorded as the absolute time according to the normal reproduction of the disc. Therefore, in the preferred embodiment of the present invention, the disc scan is performed by using the positional information of the image data corresponding to the I-frame contained in the disc information file F0.

Fig. 2 is a block diagram of a DVD system for performing the disc scanning method of the present invention, in which information data contained in the disc 100 and the disc 100 is reproduced, and the disc information file F0 is entered in the disc execution mode. DVD player which detects only image data corresponding to I-frame among image data recorded in files 1 (F1) to 99 (F99) by referring to position information of image data corresponding to the recorded I-frame, and decodes and outputs the image data. The control unit 300 controls the general operation of the DVD player 200 and the disk scan, and the key input unit 400 providing a key signal for the disk scan to the control unit 300.

In this case, the DVD player 200 includes a deck unit 210 for reading audio and video information data recorded on the disc 100, and a digital signal for digital signal processing of the audio and video information data read by the deck unit 210. The processor 220 decodes and outputs the audio and video information data provided from the digital signal processor 220, and detects the position information of the image data corresponding to the I-frame included in the disc information file F0. It is composed of an MPEG decoder 230 provided to.

FIG. 3 is a detailed flowchart of the disk scanning method of the present invention. Referring to FIG.

First, when the DVD disc 100 is mounted on the deck unit 210 (S1), the optical pickup device (not shown) of the deck unit 210 may have TOC (Table Of Comtents) information of the disc 100. Information in the disc information file F0 area is read (S2) and provided to the digital signal processing unit 220.

The digital signal processing unit 220 detects and provides TOC information to the control unit 300, and digitally processes the information of the disc information file F0 area to provide the MPEG decoder 230.

The MPEG decoder 230 decodes the information of the disc information file F0 area and provides it to the control unit 300. The control unit 300 provides information of the disc information file F0 area to the internal memory (not shown in the drawing). To be stored (S3). At this time, the information of the disc information file area F0 includes the position information of the image data corresponding to the I-frame as described above.

The DVD player 200 then performs normal playback of the disc 100 (S4). As the DVD player 200 performs normal playback, audio and video data contained in files 1 (F1) to 99 (F99) of the disc 100 are sequentially read and provided to the digital signal processor 220, and the digital signal is received. The processor 220 demodulates the read audio and video data, provides the MPEG decoder 230 by detecting a frame synchronization signal, detecting an error, and correcting an error, and sub-data included in the audio and video data stream. Is detected and provided to the control unit 300.

The MPEG decoder 230 decodes and outputs audio and video data provided from the digital signal processor 220.

As such, when the key signal corresponding to the disk scan is provided from the key input unit 400 to the control unit 300 during the normal playback of the DVD player 200 (S5), the control unit 300 provides the sub signal provided from the digital signal processing unit 220. The data is analyzed to detect the current playback position of the disc 100 (S6). At this time, the sub data are data inserted at regular intervals in the audio and video data streams as is well known in the art, and are data in which the reproduction position of the disc is expressed in absolute time.

When the current playback position on the disc 100 is detected, the controller 300 refers to each position information of the image data corresponding to the I-frame stored in the internal memory, and then the image data corresponding to the I-frame closest to the current playback position. Search for the location of. As a result of the search, when the position of the image data corresponding to the I-frame closest to the current playback position is detected, the controller 300 determines that the optical pickup device of the deck unit 210 corresponds to the I-frame closest to the current playback position. The deck unit 210 is controlled to jump to the position of (S7). The deck unit 210 causes the optical pickup device to jump to the position of the image data corresponding to the I-frame closest to the current playback position under the control of the controller 300.

The optical pickup apparatus jumps to the position of the image data corresponding to the I-frame closest to the current playback position, and then reads the image data corresponding to the I-frame at the position and provides it to the digital signal processor 220 (S8). do.

Accordingly, the digital signal processor 220 digitally processes the image data corresponding to the I-frame provided from the deck unit 210 to the MPEG decoder 230, and the MPEG decoder 230 decodes and outputs the same. When decoding of image data corresponding to the I-frame is completed, the result is provided to the controller 300.

When the control unit 300 receives a signal indicating that decoding of the image data corresponding to the I-frame is completed from the MPEG decoder 230, the controller 300 refers to each position information of the image data corresponding to the I-frame stored in the internal memory. In step S8, the position of the image data corresponding to the I-frame located at a position N (N is an integer) from the image data position corresponding to the I-frame reproduced is determined (S9). Then, the control unit 300 corresponds to the I-frame in which the optical pickup device of the deck unit 210 is located by the N (N is an integer) position away from the image data position corresponding to the I-frame reproduced in S process. The deck unit 210 is controlled to jump to the position of the image data (S10). The deck unit 210 controls the internal optical pickup device under the control of the control unit 300 so that the I-frame is separated from the image data position corresponding to the I-frame reproduced in step S8 by the N (N is an integer) position. Jump to the position of the image data corresponding to.

The optical pickup apparatus jumps to the position of the image data corresponding to the I-frame located N (N is an integer) away from the image data position corresponding to the I-frame reproduced in step S, and then the I of the position The image data corresponding to the frame is read out and provided to the digital signal processor 220 (S11 and S8).

Accordingly, the digital signal processor 220 digitally processes the image data corresponding to the I-frame provided from the deck unit 210 to the MPEG decoder 230, and the MPEG decoder 230 decodes and outputs the same. When decoding of image data corresponding to the I-frame is completed, the result is provided to the controller 300. Therefore, the controller 300 repeatedly performs the above-described process S and performs disk scan while jumping at intervals of the N-th position on image data corresponding to each I-frame (S8, S9, S10, and S11).

As described above, the present invention performs a faster disk scan by detecting the position data of the image information corresponding to the I-frame in advance and then performing a disk scan while jumping a predetermined interval with respect to the image information corresponding to the I-frame. It can work.

Claims (1)

A method of scanning a disc of a DVD system in which picture data is compressed in a file area and playback is performed on a disc in which the location information of image data corresponding to an I-frame among the picture data is recorded in a disc information file (F0) area. To; A first step of storing position information of image data corresponding to the I-frame; When switching to the disc scan mode during the normal playback mode of the DVD system, the image corresponding to the I-frame closest to the current playback position is referred to by referring to the position of the image data corresponding to the I-frame stored in the first step. Reproducing data; After the second step, the image data corresponding to the I-frame stored in the first step is referred to, and the image data corresponding to the I-frame is jumped by a predetermined interval, corresponding to the I-frame at the corresponding position. And a third step of playing back image data.