KR0144048B1 - Method of video scanning in a video compact disc player - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a visual scan (SCAN) of a video CDP, and more particularly, to an image scanning method of a video CDP in which an image scan is performed while reproducing a normal screen.

In the present invention, when the decoding of the reference I-picture in the MPEG decoder unit is completed, the MPEG micom transmits a track jump enable signal to perform a track jump to the CD micom, and the CD micom enables the track jump from the MPEG micom. By performing a track jump only when a signal is applied, an image scan is performed to prevent a screen breakage during scanning.

Description

How to scan video from video CDP

1 is a diagram illustrating track jump during image scanning of a conventional video CDP.

2 is a video CDP configuration diagram to which the present invention is applied.

3 is a flowchart illustrating a CD microcomputer control process during image scanning in the present invention.

4 is a flowchart illustrating an MPEG microcomputer control process when scanning an image according to the present invention.

5 is an explanatory diagram for explaining a track jump method when scanning an image according to the present invention.

* Explanation of symbols for main parts of the drawings

1: CD section 2: MPEG decoder section

3: CD Micom 4: MPEG Micom

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a visual scan (SCAN) of a video CDP, and more particularly, to an image scanning method of a video CDP in which an image scan is performed while reproducing a normal screen.

In the conventional video CDP, as shown in FIG. 1, the image scanning method is performed by the CD microcomputer controlling the CD unit for a predetermined time (Δt) regardless of the state of MPEG, and the predetermined track (m). The image scan is performed by repeating the track jump.

In addition, the MPEG microcomputer controlling the MPEG decoder selects and decodes only the I-picture (Intra picture), which is a reference among the video bit stream data input from the CD unit, and decodes the P-picture (predict picture) and the B-picture (Bidirectional picture). The control implements a skip operation without decoding to decode only the I-picture to implement a scan function.

However, such a conventional video CD repeats the video decoding by repeating the decoding and track jump process of the I-picture as a reference. In this case, the CD decoder in the CD controls the track jump irrespective of the MPEG microcomputer in the MPEG section. If the track jump is performed while the current I-picture is being decoded, an error occurs in the I-picture, which causes the screen to be broken due to incorrect decoding.

Accordingly, an object of the present invention is to provide a method of scanning an image of a video CDP, which allows an image scan to be performed while reproducing a normal screen during image scanning.

The method for achieving the object of the present invention is a method of scanning images by the track jump method under the control of the CD micom and MPEG micom, when the CD micom detects a scan key input transfers the scan status to the MPEG micom A first process of waiting for input of a track jump enable signal capable of track jump; A second step of controlling the CD track to jump the disc track by a predetermined track when the track jump enable signal is received in the standby; and to perform normal playback when the track jump disable signal is received; After jumping the preset disc track, the MPEG microcomputer skips the set number of the input bit stream data and skips until the first I-picture is input among the input bit stream data when the skip of the set number of pictures is completed. A third process of performing; A fourth process of decoding the I-picture first input during the skip operation and setting the I-picture decoding completion flag to on; When the I-picture decoding completion flag is turned on, the MPEG microcomputer performs a fifth process of transmitting a track jump enable signal to perform a track jump to the CD microcomputer.

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

2 is a block diagram of a video CD to which the present invention is applied. As shown in FIG. 2, a CD unit 1 and a CD unit 1 which reproduce data from a video compact disc and transfer the data to the MPEG decoder unit 2 are shown in FIG. MPEG decoder unit 2 for decoding the transmitted bit stream data, CD micom 3 for controlling the CD unit 1 while interfacing data with MPEG microcomputer 4, and CD microcom 3 and data. It is composed of an MPEG microcomputer 4 which controls the MPEG decoder unit 2 while interfacing with it.

Referring to FIG. 3 to FIG. 5 attached to the video scanning process of the present invention with reference to the video CD to which the present invention configured as described above is applied as follows.

First, as shown in FIG. 3, when the CD micom 3 that controls the CD unit 1 detects a scan key input from the outside, the current CDP is used as the MPEG microcom 4 that controls the MPEG decoder unit 2. It tells that the state of is scan state.

The CD microcomputer 3 waits for the track jump enable signal (S1).

At this time, when the CD micom 3 receives the track jump enable signal output from the MPEG micom 4, the CD micom 3 controls the servo and digital signal processing unit in the CD unit 1 to track the disc. Control to jump by a predetermined m track (S2).

On the contrary, when the track jump disable signal is output from the MPEG microcomputer 4, the CD microcomputer 3 controls the CD unit 1 to play the tracks of the disc normally (S3).

On the other hand, when the MPEG microcomputer 4 receives a scan command from the CD microcomputer 3 as shown in FIG. 4, the P-picture and the B-picture of the bit stream which are basically reproduced and applied by the CD unit 1 are applied. Skips without decoding, and controls the MPEG decoder unit 2 to decode only the I-picture.

In this process, the number of I-pictures recorded on the disc varies depending on the software of the video compact disc.

Therefore, when a large number of I-pictures are recorded, when the I-picture is decoded and displayed, the screen change changes very quickly, resulting in visual fatigue.

In order to prevent this, in the present invention, the MPEG microcomputer 4 skips the I-picture once and then decodes the picture without a predetermined number of n pictures for a delay for a predetermined time, and the skip of the set number of pictures is performed. Upon completion, the MPEG decoder unit 2 is controlled to decode the first I-picture of the bit stream data obtained from the CD unit 1 (S5-S9).

Thereafter, when decoding of the first I-picture that is met first, in order to display the new decoded screen, the MPEG microcomputer 4 controls the MPEG decoder 2 to change the display point from the previous point to the current point (S11). In addition, the MPEG microcomputer 4 sets the I-picture decoding completion flag on to transmit the track jump enable signal so that the track jump can be performed to the CD microcomputer 3 controlling the CD unit 1.

In addition, the screen skip count variable k is initialized to 0 in order to delay the set number of pictures (n picture) (S12).

That is, as shown in FIG. 5, when the I-picture decoding completion flag is checked and the flag is turned on, the track jump enable signal is transmitted to the CD microcomputer 3 controlling the CD unit 1 (S14).

Then, the CD micom 3 performs the track jump by the set track only when the track jump enable signal is input, thereby scanning.

As described above, according to the present invention, when decoding of an I-picture, which is a reference in the MPEG decoder unit, is performed by performing a track jump, scanning can be prevented by breaking the screen. As a result, the track jump is performed after a delay, thereby providing stability during scanning.

Claims (1)

In the method of scanning images by track jump method under the control of CD micom and MPEG micom, when the CD micom detects a scan key input, the scan state is transmitted to the MPEG micom and a track jump enable signal capable of track jumping is provided. A first process of waiting for an input; a second step of controlling the CD micom to jump the disc track by a predetermined track when the track jump enable signal is received during the standby, and to perform normal playback when the track jump disable signal is received. And after jumping the preset disc track, the MPEG microcomputer skips the set number of bits from the input bit stream data and skips until the I-picture is applied among the input bit stream data when the skip of the set number of pictures is completed. A third process of performing an operation; if an I-picture is applied during the skip operation, the Ip a fourth step of decoding the icture and setting the I-picture decoding completion flag to on when the decoding is completed; enabling the track jump to perform a track jump to the CD micom when the I-picture decoding completion flag is turned on; And a fifth process of transmitting a signal.