KR100301473B1 - Recording and reproducing method for time lapse vcr - Google Patents

Abstract

PURPOSE: A method for recording and playing a time lapse VCR(Video Cassette Recorder) is provided to half the capacity of a memory by repeatedly outputting the video signals in a field previously regenerated for the regeneration of a field missed in a recording process and to prevent the flickering of a picture due to a time base error in a fast moving picture. CONSTITUTION: A method for recording and playing a time lapse VCR comprises the steps of compressing video signals inputted from the outside, selecting video signals corresponding to one field among video signals of one frame and storing the selected compressed signals in a memory bank, respectively outputting the video signals as the video signals of an odd field or an even field after storing the video signals read out from a tape in the memory bank by the unit of a field, and extending the video signals output to the odd field and the even field.

Description

RECORDING AND REPRODUCING METHOD FOR TIME LAPSE VCR}

The present invention relates to the recording and playback technology of the Time Lapse VCR capable of intermittent recording. In particular, the present invention relates to a time lapse that is suitable for drastically reducing the capacity of the recording memory and preventing shaking on a fast moving screen. The present invention relates to a recording and reproducing method of V-Cal.

In the time-lapse VRC according to the prior art, in the recording mode, the input video signal is data-framed, that is, the consecutive odd field and even-field data is stored in one unit, and temporarily stored in the DRAM bank and read again. Recorded on magnetic tape.

Further, in the playback mode, the video data recorded on the tape is reproduced and output in units of frames as described above.

However, what cannot be overlooked here is that when the video signal is recorded in units of frames as described above, the odd and even fields are temporally in NTSC. Since there is a difference of about sec, tremors appear on a screen moving at high speed.

As described above, in the conventional Time Lapse VRC, video signals are processed in units of frames. In the NTSC method, a shaking phenomenon occurs in a fast moving screen due to the time difference between odd and even fields. As a result, processing requires a larger amount of memory than processing by field, thereby resulting in a cost increase.

Therefore, the technical problem to be achieved by the present invention is to process and store the video signal of one field among the input video signals of one frame in the time-lapse recording mode, but discard the video signal of the other field and output from the tape in the playback mode. The present invention provides a method for recording and reproducing a time-lapse VSR for processing a video signal of a field after the reproduction process by overlapping a video signal of a field that has been reproduced immediately before.

1 is a block diagram of a time-lapse VRC to which the recording and reproducing method of the present invention is applied.

2A is a signal flowchart of a recording method according to the present invention;

2b is a signal flow diagram of a reproducing method according to the present invention;

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

1: A / D converter 2: Compressor

3: central processing unit 4: memory bank

5: Extender 6: D / A Converter

According to another aspect of the present invention, there is provided a method of recording and reproducing a time-lapse video signal, comprising: a first step of compressing a video signal input from an external source; A second step of selecting and storing only one odd or even one video signal from one frame of the video signal when the compressed video signal is stored in a memory bank; A third step of storing the video signals read from the tape in the memory bank in units of one field and outputting the video signals of odd and even fields respectively; And a fourth step of decompressing the video signal output by the third step.

1 is a block diagram of a time-lapse VRC to which the recording and reproducing method of the present invention is applied. As shown in FIG. 1, an A / D converter 1 for converting an analog input video signal V _in to a digital signal is shown. ; A compressor (2) for compressing the digital video signal output from the A / D converter (1) at a predetermined compression rate; Of the video signals of one frame sequentially output from the compressor 2, only one or even one field video signal is stored in the memory bank 4, and the video signal of one field in the memory bank 4 in the playback mode. A central processing unit (3) which reads twice and outputs the video signals of odd and even fields;

An expander (5) which expands and outputs the video signal of the odd even field continuously outputted from the central processing unit (3) to the original video signal; The D / A converter 6 converts the digital video signal output from the expander 5 into an analog video signal and outputs the same. The operation of the present invention configured as described above is described in detail with reference to FIGS. 2A and 2B. The explanation is as follows.

First, a time lapse recording process of an input video signal will be described with reference to FIG. 2A.

In the time-lapse recording mode, an analog video signal (V _in ) input to V-Cal is converted into a digital signal through the A / D converter 1, and then compressed by the compressor 2 at a predetermined compression rate to be processed centrally. Supplied to the apparatus 3.

At this time, the CPU 3 stores the video signals sequentially input from the compressor 2 in the memory bank 4, and stores the video signals of odd field in the memory bank 4. Subsequently, even-field video signals inputted are discarded without being stored in the memory bank 4.

The video signal stored in the memory bank 4 is read again and recorded on a magnetic tape (not shown).

This operation is repeatedly performed while the analog input video signal V _in is supplied.

In the above description, the recording mode is performed by taking the video signal of the odd field and discarding the video signal of the even field, as an example. However, the same effect can be obtained even when the processing is reversed.

Meanwhile, referring to FIG. 2B, the reproduction output process of the video signal recorded on the tape is described below.

In the reproducing mode, the video signal recorded on the tape is read out and stored in the memory bank 4 in units of fields, where only the odd field is an odd or even field.

However, it is necessary to finally output a complete one-frame video signal including both odd and even fields.

For this purpose, when the central processing unit 3 reads the video signal from the memory bank 4, the video signal of the odd field is normally read in synchronization with the vertical synchronization signal of the odd field, and then the video of the odd field read immediately before. Read the signal once more and insert the vertical sync signal of the even field.

As a result, an odd field video signal is read twice, one of which is output as an odd field video signal, and the other is output as an even field video signal. This operation is performed repeatedly.

The video signal output through the above-described processing is extended to the original video signal through the expander 5, and then output as an analog video signal through the D / A converter 6 again.

By doing in this way, it is possible to output a video signal having almost the same image quality as using the memory bank of one field capacity but using the memory bank of one frame capacity.

As described in detail above, the present invention processes and stores the video signal of one field among the input video signals of one frame in the time-lapse recording mode, but discards the video signal of the other field and plays back from the tape in the playback mode. After reproducing the video signal of one output field and processing the missing field in the recording step, the video signal of the immediately played field is duplicated and processed. In this case, it is possible to reduce the screen blurring caused by the time difference between odd and even fields (1/60 seconds) in a fast moving screen.

Claims (5)

A recording process of storing only video signals of odd or even fields among video signals input from the outside in a memory bank in field units; Recording and reproducing the video signal read out from a tape in the memory bank in units of fields, and then reading the data twice in succession and outputting the video signals in odd and even fields. . 2. The method of claim 1, wherein only the video signal of an odd field is selected and stored in a memory bank when a recording process is performed. [4] The recording method of claim 1 or 2, further comprising inserting and outputting a vertical synchronization signal of an even field into a video signal of an odd field to be output. How to play. The method of claim 1, wherein when performing a recording process, only video signals of even fields are selected and stored in a memory bank. The method of claim 1, further comprising the step of extending and outputting the compressed video signal output from the memory bank.