KR20000042574A - Method for searching data of guarding system by using digital vcr - Google Patents

Abstract

PURPOSE: A method for searching data of a guarding system by using a digital VCR is provided to quickly search an image signal in a part needed to search from image signals stored. CONSTITUTION: A present time data about an image signal retained in a sub code of each track is stored. A VISS(VHS index search system) signal is recorded at a predetermined time interval. In entering time data in a position needed to search, the time data in a present position of tape is detected by reading the sub code of a present track. A different time between the time data in the needed position and the present detected time data is detected. A number of VISS is detected during a fast packing. When the number of VISS corresponding to the different time is detected, the time data in the present position of tape is detected by reading the sub code in the position of track. If the detected time data and the time data inputted by a user are conformed, a playback is performed from the position. If not so, it is performed from the detecting process of different time band again.

Description

DATA SEARCHING METHOD FOR CRIME PREVENTION SYSTEM USING DIGITAL VCR

The present invention relates to a method for storing a video signal input from a camera using a digital VR, in particular, using a digital VR to quickly and easily search for a video signal of a part to be searched from a previously stored video signal. A method for searching data in a system.

In general, a security system for storing a video signal photographed using a digital VR converts the analog video signal photographed from the camera to a digital video signal, and then it is discrete cosine transform (DCT), quantization, variable length coding, formatting, etc. The compressed video signal is decompressed by the error correction code and recorded on the tape.

At the time of reproduction, the stored video signal is read and displayed on the monitor through error correction, deformatting, variable length decoding, inverse quantization, and inverse discrete cosine conversion.

However, when the user searches for the situation of the accident time in the recorded data due to theft or any accident, the user has to take a lot of time because the user has to search the entire recorded tape one by one.

In order to solve the above problems, the present invention inserts data representing the current time into sub-codes of each track when recording the photographed video signal on a tape, and vis (VISS: VHS Index Search System) every predetermined time. To provide a data search method of a security system using a digital VRL that inserts and records a signal so that it can be easily searched for image data at a desired time by comparing and displaying this data and time data input by a user during a subsequent search. There is this.

Therefore, in the data search method of the security system using the digital VR of the present invention, the search data for recording the current time data of the video signal recorded in the subcode of each track, and recording the VIS signal every predetermined time. Recording process; A current time detection process of reading time data of a current tape position by reading a subcode of a current track when time data of a position to be searched from a user is input; A difference time detection process of detecting a difference time between time data of a desired position input from the user and currently detected time data; A bis signal searching process of detecting the number of bits while performing fast forward (FF) when the difference time is detected; A time data detection step of detecting time data of the current tape position by reading a sub code of the track position when the number of bits corresponding to the difference time is detected by the vis signal searching process; And comparing the time data detected by the time data detection process with the time data input from the user, and reproducing from the position if the time data are matched, or performing the process again from the time difference detection process.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a block diagram showing an apparatus for recording and reproducing a security system using a digital VR according to the invention.

2 and 3 are a flow chart showing a data search method according to the present invention.

4 is a diagram showing a track structure of a general digital VR;

5 is a diagram showing the structure of data recorded in a sub code according to the present invention;

Explanation of symbols on the main parts of the drawings

100: camera 110: recording signal initial part

111: A / D converter 112: video signal compression unit

113: search signal insertion unit 120: recording unit

130: deck 140: playback unit

150: playback signal processor 151: video signal extension

152: D / A converter 153: search signal detector

160: display unit 170: control unit

180: key input section 190: timer

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

As shown in FIGS. 2 and 3, the data searching method of the security system using the digital VR according to the present invention includes a search data recording process (ST100, ST110, ST120), a current time detection process (ST200, ST210, ST220, ST230, difference time detection process ST240, bis signal search process ST250, time data detection process ST260, ST270, ST280, ST290, ST300, and playback process ST310, ST320.

The search data recording process (ST100, ST110, ST120) records the current time data, that is, the year, month, day, day of the week, hour, minute, etc., in the subcode on the tape when the recording mode is entered, and then the position of the tape to be searched. It is a process of inserting and recording a bis signal every predetermined time so as to search quickly.

The subcode reading process ST200, ST210, ST220 is a process of reading the subcode of each track when time data of a position to be searched from a user is input.

The difference time detection process ST230 or ST240 is a process of calculating a difference time between time data detected from the subcode and time data input from the user.

When the time difference is detected by the time difference detection process, the non-signal search process ST250 performs a fast forward FF and searches for a non-signal signal during the process.

The time data detection process (ST260, ST270), ST280, ST290, ST300 is a process of re-detecting the time data at the position of the tape desired by the user by searching for the vis signal by the vis signal search process. A first step (ST260, ST270) of stopping fast forwarding when the number matches the number of non-signal signals corresponding to the difference time; When the tape is stopped by the first step, it is played back and then the second step (ST280, ST290, ST300) is performed to detect the current time data of the subcode at that position.

The playback processes ST310 and ST320 determine whether the current time data detected from the subcode coincides with the time data desired by the user, and continues playback if they match. Otherwise, the playback process is performed again from the difference time detection process.

This will be described in detail with reference to FIGS. 1 to 5.

First, the analog image signal photographed from the camera 100 is converted into digital image data through the A / D converter 110 of the recording signal processor 110.

The data converted into the digital video signal is applied to the video signal compression unit 112 and compressed and applied to the recording unit 120 by performing a series of processes such as discrete cosine transform (DCT), quantization, variable length encoding, and formatting. The track is recorded on the tape inserted in the deck 130.

At this time, as shown in FIG. 4, the structure of the track is 2 bytes of margin, 3 bytes of preamble, 4 bytes of subcode, 3 bytes of postamble, 3 bytes. IBG, 1 byte preamble, 336 bytes main code, 2 bytes postamble, and 2 bytes margin.

Therefore, the digital video signal is stored, i.e., recorded, at the position of the main code, and the data for the current time is recorded in the subcode.

This process is explained in more detail as follows.

When recording starts, the control unit 170 reads data on the current time applied from the timer 190 to record the current time data in a subcode of each track on the tape, and then the search signal insertion unit 113. To be applied.

The search signal insertion unit 113 configures data so that data on the current time applied from the control unit 113 can be recorded in the subcode of each track, which is shown in FIG. 5. It is composed of data such as, month, day, day, hour, and minute.

That is, since one hour is 60 minutes in total, 6 bits can be expressed in minutes, and since 1 day is 24 hours, 5 bits are represented, and 1 week is 7 days, so 3 bits can be expressed.

For example, Sunday if the bit representing the day of the week has a value of '000', Monday if it is '001'. Tuesday if '010, Wednesday if' 011 '. Thursday if '100'. Friday if '101'. If it is '110', it can be expressed as Saturday.

In addition, since one month is 31 days, it can be represented by 5 bits. Since a year is 12 months, 4 bits, that is, '0000' is January, '0001' is February, '0010' is March, ..., '1011' Can be expressed in November and '1100' in December.

In addition, the representation of the year may be represented by 7 bits so that 100 years can be expressed as a cycle.

If the recording time is 2:30 pm on November 18, 1997, '1100001' is written in the bit representing the year in the subcode of FIG. 5, and '1011' is represented in the bit representing the month. '10010' is written in the bit, '010' is written in the bit representing the day of the week, '01110' is written in the bit representing the hour, and '011110' is written in the bit representing the minute.

Therefore, the search signal inserting unit 113 outputs the data indicating the current time to the recording unit 120, and the recording unit 120 transmits the code to the image data of the video signal compression unit 112. In addition to recording in the main code, data representing the current time applied from the search signal insertion unit 113 is recorded in the sub code.

In addition, the search signal insertion unit 113 outputs a VIS signal to the recording unit 120 every predetermined time (a time of about 5 minutes for convenience of description) under the control of the control unit 170. To record on the tape inserted into the deck 130 (ST100, ST110, ST12).

Here, the VHS Index Search System (VISS) refers to recording a signal on a tape at a desired time in order to facilitate the search for a position to be viewed later when recording or playing back on a general VHS tape. By running the tape at a high speed by the command, only this vis signal is searched, so you can quickly search for the desired position without looking at the screen.

After the time data is recorded on the tape together with the video data by the above process, when the user wants to search for the situation at that time due to an accident, such as an accident, the time data of the recorded video (eg, 1997 10 When the month 20 is inputted at 18:05 through the key input unit 180, the controller 170 drives the deck 130 to play back the tape (ST200, ST210).

Therefore, the data read from the playback section 140 is applied to the search signal detection section 153 to detect the time data of the current position of the tape written in the subcode (ST220, ST230).

The time data detected by the search signal detector 153 is applied to the controller 170 to detect the time difference by comparing the time data input by the user with the time data detected from the current subcode (ST240).

For example, if the time data detected from the subcode on the current tape is 02:05 October 20, 1997, the difference from the time you want to search is 16 hours (October 20, 1997 18:05-1997). October 20, 02:05).

Since the vis signals for high-speed search are recorded every 5 minutes, the 16 hours are converted into minutes, which is 960 minutes, and when converted into the number of vis signals, the number is 192 (960 minutes ÷ 5 minutes).

As such, when a time difference is detected, the controller 170 drives the deck 130 to perform fast forward (FF), and at the same time, the search signal detector 153 performs fast forward through the playback unit 140. To detect a bis signal.

When the number of the vis signals detected by the search signal detector 153 reaches 912, the controller 170 controls the deck 130 to stop at the position and performs the playback operation again (ST260 and ST270). , ST280).

Accordingly, the reproduction unit 140 reads the data recorded on the tape and provides the data to the search signal detection unit 153. The search signal detection unit 153 detects only the time data of the subcode among the input data and controls the control unit ( 170) (ST290, ST300).

The controller 170 compares the detected time data with the time data to be searched by the user again, and controls the deck 130 to perform a playback operation from the position of the tape when the data is matched with each other. Is applied to the video signal extension 151.

Therefore, the image signal decompression unit 151 decompresses the compressed data by performing a series of processes such as deformatting, variable length decoding, inverse quantization, and inverse discrete cosine transform, and the data is converted into a D / A converter 152. Is converted into an analog signal and displayed to the user through the display unit 160 (ST310, ST320)

On the other hand, if the comparison result between the time data detected by the controller 170 and the time data input from the user does not match, the controller 170 performs the difference time detection process ST240 again ( ST310, ST240).

As described above, in the data search method of the security system using the digital VC according to the present invention, when recording the photographed video signal on the tape, data representing the current time is inserted into the subcode of each track. By inserting and recording a vis signal every predetermined time, there is an effect that the desired video data can be automatically and quickly searched by the vis signal and time data in a subsequent search.

Claims (2)

A search data recording process of recording current time data of a video signal recorded in a subcode of each track, and recording a VIS signal every predetermined time; A current time detection process of reading time data of a current tape position by reading a subcode of a current track when time data of a position to be searched from a user is input; A difference time detection process of detecting a difference time between time data of a desired position input from the user and currently detected time data; A bis signal searching process of detecting the number of bits while performing fast forward (FF) when the difference time is detected; A time data detection step of detecting time data of the current tape position by reading a sub code of the track position when the number of bits corresponding to the difference time is detected by the vis signal searching process; And compares the time data detected by the time data detection process with the time data input from the user, and reproduces the data from the position if it matches. Otherwise, the data is reproduced from the time difference detection process. Data search method of security system using. The method of claim 1, wherein the time data detection process is performed. A first step of stopping the fast forwarding when the number of the detected vis signals coincides with the number of the vis signals corresponding to the difference time; And a second step of detecting the current time data of the subcode at the position after the tape is played back by the first step, wherein the tape is stopped.