KR100222681B1 - Method and system for realizing shuttle mode in a system using moving picture processing apparatus - Google Patents

Abstract

The present invention provides a video screen search system of a video apparatus having a recording medium (201) for storing data for recording / reproducing an image and a display unit (207) for displaying an image, the screen constituting the GOP of the video. And a frame memory configured to search for the previous and subsequent screens by recording / reproducing by one screen unit in the GOP.

Description

Method and system for realizing shuttle mode in system using moving image processing device

1 is a GOP structure diagram according to an embodiment of the present invention.

2 is an embodiment circuit diagram according to an embodiment of the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a function implementation circuit using an MPEG-2 stream in a video device, and more particularly, to a shuttle mode implementation system for searching still images on a single screen basis.

In general, a shuttle function in an image processing apparatus monitors a portion of another song and image during a high-speed search, and is analogously widely used and used in an image processing apparatus, that is, a VTR. This function has a problem in that the still picture cannot be viewed in one screen unit.

Accordingly, an object of the present invention is to provide a system in which the frame memory corresponding to the number of screens constituting the GOP in MPEG video data can be searched for the front and rear screens by one screen unit in the GOP.

In accordance with another aspect of the present invention, there is provided a video screen search system of a video apparatus, comprising: a recording medium on which an image is recorded / reproduced, first and second frame memories for storing image data in units of frames, and the image recording medium. A decoder for decoding the data output from the first switch, a first switch for switching the output data of the decoder to be selectively applied to the first and second frame memories, and a data for selecting the data output from the first and second frame memories. It is characterized by consisting of two switches.

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

1 shows a structure of a GOP according to an embodiment of the present invention, and FIG. 2 shows an embodiment of a shuttle according to an embodiment of the present invention, and a recording medium 201 in which predetermined image data is stored. And a display unit 207 for displaying an image, and a controller 203 for controlling access to the recording medium 201 to reproduce the recorded data and controlling access to the current GOP screen and the previous GOP screen. To

First and second frame memories FR1 and FR2 stored in frame units by dividing the current GOP screens and previous GOP screens;

A decoder 205 for decoding data output from the recording medium 201,

A first switch for switching the data decoded by the decoder 205 to be written to the first and second frame memories FR1 and FR2 according to whether the GOP screen or the previous GOP screen is currently under the control of the controller 203. (SW1),

A second switch SW2 that switches to input to the display unit 207 by the control of the controller 203, whether the current GOP screen or the previous GOP screen of the first and second frame memories FR1 and FR2. It is composed.

Therefore, the present invention will be described in detail with reference to FIG. 1 through FIG.

The MPEG video stream consists of three frame data: I (Intra), P (Predictive), and B (Bidirectional). These are combined to form one GOP, one example of which is shown in FIG. Here, the GOP size is expressed as a value of N, but 15 is generally the most widely used. I frame is a screen that can be restored by itself alone, and P and B frames are screens that can be restored by referring to other screens. Therefore, it can be seen that it is impossible to restore the screen at an arbitrary position in the GOP. That is, the data reproduced on the recording medium 201 is decoded by the decoder 205, but must be decoded from the beginning of the GOP. In order to search by one screen unit, all data for one GOP must be included. Accordingly, it can be seen that as many frames of the frame memory FRi as the GOP are required. In case of reaching the boundary of GOP while searching by one screen unit, additional memory is needed to store GOP data to be processed next. However, when the user designates a shuttle mode (here, a mode of searching for an image forward or backward by one screen unit) at a moment, the screens of the GOPs currently in progress are read into the frame memory at that moment. At the same time, the previous GOP data is read into the auxiliary frame memory (this is in case the user performs a backward search). Subsequent GOPs are loaded into auxiliary frame memory in advance. This is to facilitate the smooth progress of the search. For example, if the GOP size is 15, when the user reaches the position of the 10th screen while searching the screen, the next GOP data is likely to be read in advance because the screen after the current GOP is likely to be read. Read to auxiliary frame memory. In contrast to the above, when the user reaches the position of the fifth screen while searching backward, the previous GOP data is loaded in the auxiliary frame memory. This allows the user to navigate the screen across the boundaries of the GOP. The example position values (5th position and 10th position) are not absolute values, and appropriate values may be selected and used. That is, the third screen from the GOP start position and the third screen from the last position are selected as the threshold positions. If there is a current search pointer at the selected position, the GOP data, which is expected to be read next, is loaded into the auxiliary frame memory. The next question is how to know where the GOP starts. In the case of a GOP later than the current location, it doesn't matter where it starts. This is because the position can be found in normal playback. The problem is that the GOP location before the current location is solved by allocating a small amount of memory. In other words, it is to record the position where GOP starts during normal playback in memory, and there is generally no use of shuttle mode for a long time, so if there are only 3-4 positions based on the current position, there is no problem. Even if you don't have information about the starting position of the previous GOP, you can get it.

For example, in the case where the ATV bit stream is recorded on the SD tape, for example, since the SD format records one screen for 10 tracks, one screen is recorded for 10 tracks on average in the ATV system. The reason for using the expression "average" here is that the data amount can be increased or decreased depending on the complexity of the screen and any of I, P, and B as shown in FIG. 1 (data amount I frame> P frame> B frame). ). Considering this, it can be said that one GOP is recorded over 150 tracks on average (assuming GOP size is 15). Therefore, considering the case where the data volume is large, the GOP data is decoded from a position far before 150 tracks. Is written to the auxiliary frame memory. At this time, if the next GOP matches the position of the GOP currently being processed, it means that the previous GOP has been successfully found. If the GOP is not matched and has a value earlier than the current position, it means that another GOP exists. To find the GOP just before the current location. A detailed example for this is described in detail with reference to FIG. 2. When entering the shuttle mode, the controller 203 writes the GOP data of the current position to the first frame memory FR1 and writes to the second frame memory FR2. Record the previous GOP data. The memory used here can be interchanged. [Ie, current position data in the second frame memory FR2, previous data in the second frame memory FR2] Therefore, if the screen used in the current shuttle mode is included in the first frame memory FR1, the second frame memory ( FR2) is used as an auxiliary frame memory. The controller 203 of FIG. 2 reads the position of the search screen on the first and second frame memories FR1 and FR2 to determine data to be read into the auxiliary frame memory, and the first and second frame memories FR1 and FR2. Control frame for which frame memory should be used. The controller 203 informs the start position of the GOP on the recording medium 201.

Considering the case where the GOP data of the current position is read into the first frame memory FR1, the first switch SW1 is connected to the first frame memory FR1 until the GOP data is read by the control of the controller 203. After reading the data, the controller 203 connects the first switch SW1 to the second frame memory FR2 and the second switch SW2 to the first frame memory FR1. The data read from the previous GOP is recorded in the second frame memory FR2. (After the initial state of the shuttle mode, the data most likely to be used next is recorded as described above). When crossing the boundary of the GOP in the screen search process, the state of the first and second switches SW1 and 2 are changed and the control signal is transferred to the first frame memory FR1 and the second frame memory FR2. The process implements shuttle mode.

As described above, in the digital image processing apparatus using the MPEG bit stream, there is an advantage that the image can be searched by one screen unit.

Claims (1)

A recording medium 201 storing predetermined video data, a display unit 207 for displaying an image, and controlling the recording medium 201 to reproduce recorded data, and display the current GOP screen and the previous GOP screen. In the system having a controller 203 for access control for the first and second frame memory (FR1, FR2) is divided into the screen of the current GOP and the previous GOP screen and stored in units of frames, The decoder 205 for decoding the data output from the recording medium 201 and the data decoded by the decoder 205 according to whether the controller 203 is currently in progress or the previous GOP screen are controlled. The first switch SW1 for switching to be written to the first and second frame memories FR1 and FR2, and whether the controller is a current GOP screen or a previous GOP screen of the first and second frame memories FR1 and FR2. 203 of In a system using a moving image processing apparatus, characterized by a read word comprised of a second switch (SW2) for switching to the input on the display unit 207, shuttle mode implementations.