KR0132860B1 - Screen searching method of video cd - Google Patents

Abstract

A screen search method for a video-CD skips an optical pickup device of the video-CD by the predetermined track number, performs a normal playback, stores it into RAM, sequentially outputs this, and thus reduces a screen search time of CD having a video information. The method includes the steps of: moving an optical pickup device by a predetermined track number when receiving a screen search command, and performing a normal playback; searching the information from the optical disk, detecting an effective video information, and storing it into a buffer; converting the stored video information to a video signal, and generating the video signal; and intermittently or successively reproducing the video information recorded on the optical disk.

Description

Screen Search Method of Video CD

1 is a view showing the structure of a compact disc.

2 is a diagram showing the configuration of a GOP according to the MPEG-1 standard.

3 is a diagram showing the structure of video data.

4 is a block diagram showing the configuration of a VIDEO-CD.

5 is a flowchart illustrating a screen navigation method according to the present invention.

The present invention relates to a screen searching method in a compact disc in which image information is recorded. A compact disc can record audio, image, and text information on an optical disc of 12 cm size. Recently, application fields such as CD-ROM, CD-I, CD-G, and VIDEO-CD have been expanded. The CD recording the audio information can easily find the beginning of the song by referring to the table of content (TOC) recorded in the lean-in area. On the other hand, since CD-G, video CD, etc., in which image information is recorded, are often not classified in a predetermined unit, in order to search for an arbitrary screen, a CD player fast forward, Rely on backward fast search and the like. However, since the FF, REW, etc. are a sequential search method, there is a problem that the search speed is increased in proportion to the separation distance between the position of the pickup device and the position where the desired screen is recorded. An object of the present invention is to provide a search method capable of searching an arbitrary screen at a high speed, which is created to overcome the above problems. According to an aspect of the present invention, there is provided a screen searching method comprising: an intermittent playback process of performing a normal playback after moving an optical pickup apparatus by an arbitrary number of tracks when a screen searching command is applied; Performing a detection process of retrieving information read from the optical disc through the intermittent playback process, detecting valid image information, and storing it in a buffer; And forming and outputting the stored image information through the detection process as an image signal. Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. The screen search method of the present invention can be applied to both a CD-G in which a still image is recorded, a VIDEO-CD in which a moving picture is recorded, and the like. 1 is a view showing the structure of a compact disc. The CD is 120 mm in diameter with a 15 mm center hole in the middle. Audio / video information can be recorded starting from 20mm in diameter up to 116mm outside diameter. The signal is recorded on tracks spirally connected to this disc. The interval between these tracks is 1.6um. Thus, one CD contains about 20,000 tracks. 2 is a diagram showing the structure of a group of pictures (GOP) in a VIDEO-CD. The VIDEO-CD records video information compressed and encoded according to the MPEG-1 standard.

Here, the GOP refers to a group of image information that can be independently decoded without depending on other image information. The order of the frame images according to the MPEG-1 standard may vary depending on the mode, but FIG. 2 shows an example in which 10 frames are one GOP.

In FIG. 2, an I picture represents an intra-frame picture, a P picture represents a predicted picture, and a B picture represents a bidirectional predicted picture. The bit rate of each picture is encoded by 19 K bytes for I pictures, 10 K bytes for P pictures, and 2.8 to 2.9 K bytes for B pictures, so that B pictures contribute most to compression encoding. Arrows displayed between I, B, and P pictures show a dependency relationship between each picture. I pictures can be decoded independently without depending on B or P pictures, P pictures can be decoded depending on I pictures, and B pictures can be decoded by I and P or B pictures. Therefore, in order to search for arbitrary image information at high speed, it is most efficient to use the information of the I image. 3 is a diagram showing the structure of a video data player. Each video data has a header and one or more GOPs attached thereto. The GOP has a header and at least one I picture attached thereto. The number of images required may vary depending on the compression mode. The B picture must be located between the I picture and the P picture, and the I picture must be located at the head of the GOP. Each picture is distinguished by a picture code. Table 1 shows an example of an image code.

Therefore, the I picture can be distinguished by analyzing the PICTURE CODE. 4 is a block diagram showing the configuration of the VIDEO system in the configuration of the VIDEO-CD player. In FIG. 4, reference numeral 10 denotes an optical disc on which a VIDEO-CD signal is recorded, 12 denotes a spindle motor for rotating the optical disc 10, and 14 denotes an optical signal along a track formed on the optical disc 10 and reflects therefrom. A pickup device for detecting the magnitude of an optical signal to be output and outputting it as a reproduction signal; processor (DSP), 18 is a decoder for inputting error correction data provided from DSP 16 to demultiplex audio / video data, and outputs video and audio data, and 20 is output from decoder 18 A central processing unit (CPU) that separates image data of I, B, and P from the video data, and restores and outputs respective image information therefrom; 22 is a random access memory (RAM) buffering the image information processed through the CPU 20, and 24 is a video that reads the image information stored in the RAM 22 to form and output it as an image signal. It is a decoder. 26 is a focus tracking servo unit for controlling the focus and tracking servo of the optical pickup device, and 28 is a rotation servo unit for controlling the rotation of the spindle motor. 5 is a flowchart illustrating a screen navigation method according to the present invention. First, when a mode for searching an arbitrary screen in the forward or backward direction is selected by the user, a signal T_JUMP requesting an N track jump operation is generated from the CPU 20 and transmitted to the focus tracking servo unit 24. The focus tracking servo unit 24 performs a track jump operation for moving the optical pickup device 12 in the forward or backward direction in response to the T_JUM signal (step 100). This value can be set at the time of manufacture or arbitrarily set by user. After the optical pickup apparatus is moved by N tracks from the current position in step 100, a normal playback operation is performed. (Step 110)

In step 110, information recorded along the tracks of the optical disc is sequentially read out and processed by the DSP 16 and the decoder 18. The CPU 20 examines the data transmitted from the decoder 18, extracts the data of the I image, records it in the RAM 22 (steps 120 to 130), and N-tracks the focus tracking servo unit 26. The signal T_JUMP requesting a jump operation is transmitted. (Step 140) The data of the I image recorded in the RAM 22 is sequentially read by the video decoder 24, formed into a video signal, and output. The search mode may be programmed to be performed continuously or intermittently, and image information at a position deviated by N tracks from the currently reproduced position is searched and displayed by repeatedly performing track jumping and normal playback. As described above, the screen search method according to the present invention, unlike the conventional search method for searching the screen while performing the playback operation at a high speed, the search time is increased by repeating the normal playback after skipping the N track. It has a shortening effect. In the present embodiment, a RAM configuration may include a method of cyclically recording and reproducing a plurality of areas having a capacity for storing an I image, but secondly, a RAM capable of simultaneously recording and reproducing. It may be conceivable to use.

Claims (2)

A method of searching for information recorded on an optical disc, comprising: an intermittent playback process of performing normal playback after moving an optical pickup device by an arbitrary number of tracks when a screen search command is applied; Repetitively performing a detection process of searching for information read from the optical disc through the intermittent playback process, detecting valid image information, and storing the image information in a buffer; And forming and outputting the stored image information as an image signal through the detection process, wherein the image information recorded on the optical disc is intermittently and continuously reproduced. 2. The screen searching method according to claim 1, wherein the information recorded on the optical disc is I, B, P image information compressed and encoded by MPEG standard, and the effective image information detected in the detection process is I image information. .