KR100205412B1 - Recording/reproducing apparatus - Google Patents

Abstract

The present invention relates to a multi-signal recording and reproducing apparatus for recording a plurality of video signals in a single tape in a DVCR format so that a plurality of divided screens are displayed on one monitor during playback. A signal input section for outputting a signal, a synchronous control section for controlling an output of the signal input section, a sub sampling section for subsampling luminance signals and chrominance signals of a plurality of video signals output from the signal input section, and A storage unit for temporarily storing a plurality of sub-sampled luminance signals and chrominance signals, a memory control unit for outputting a write signal and a read signal to the milk storage unit, and a luminance signal and a chrominance signal read from the confinement unit by switching; A switching unit for outputting the data, and a luminance signal and a color difference signal outputted from the switching unit. It is composed of a recording and reproducing unit for recording and reproducing the data, and recording the data according to the DVCR format by composing a plurality of divided screens in one frame with multiple image signals transmitted from a plurality of visual cameras or broadcasting systems such as CCTV, CATV, etc. Thus, during monitoring and playback, a plurality of divided screens are all displayed on one monitor, so that a plurality of video signals can be viewed and monitored at the same time.

Description

Multi-signal recording / playback device

1 is a view showing the shape of an input signal to a general digital CR (DVCR).

FIG. 2 is a diagram showing a 4: 1: 1 signal configuration in the DVCR of FIG.

3 is a diagram showing the pixel configuration of a 1-frame screen in the DVCR of FIG.

4 is a view showing the shape of one video signal input to the multi-signal recording and reproducing apparatus according to the present invention.

5 is a diagram showing a signal configuration subsampled by 1/4 in a multi-signal recording and reproducing apparatus according to the present invention.

6 is a diagram showing a pixel configuration of one video signal 1 frame screen in a multi-signal recording and reproducing apparatus according to the present invention.

7 is a diagram showing the pixel configuration of the entire screen in the multi-signal recording and reproducing apparatus according to the present invention.

8 is a diagram showing one frame track structure in a multi-signal recording and reproducing apparatus according to the present invention.

9 is a view showing a display screen during reproduction in the multi-signal recording / reproducing apparatus according to the present invention.

10 is a block diagram of a multi-signal recording and reproducing apparatus according to the present invention.

11 is a diagram showing a pixel configuration when performing a zoom function in the multi-signal recording and reproducing apparatus according to the present invention.

12 is a view of another embodiment showing the form of one video signal input to a multi-signal recording and reproducing apparatus according to the present invention.

FIG. 13 is a block diagram showing another embodiment of a multi-signal recording / reproducing apparatus for performing FIG. 12. FIG.

* Explanation of symbols for main parts of the drawings

61: signal input unit 61-5: synchronization control unit

62: subsampling unit 62-1 to 62-8: subsampler

63: storage unit 63-1 ~ 63-8: RAM

64: memory control unit 65: switching unit

66: DVCR

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-signal recording and reproducing apparatus, and more particularly, to record and reproduce images from a plurality of surveillance cameras on a single tape according to a digital video cassette recorder (DVCR) format. The present invention relates to a multi-signal recording and reproducing apparatus which enables simultaneous viewing and monitoring by allowing two divided screens to be displayed on one monitor.

Conventional surveillance cameras record on tape using an analog method such as VHS (Video Home System).

At this time, the amount of tape may be saved by using time lapse, that is, intermittent photography.

Then, the video input from each camera is recorded on each tape.

At this time, the data is switched from the RGB color region to the luminance-chrominance region before being compressed.

The chrominance signal is subsampled at 2: 1 horizontally and vertically, respectively.

This is due to the fact that humans are not affected by color because they are highly affected by brightness and less by color, and thus do not cause visible degradation.

At this time, the format of the digital component broadcast TV (CCIR 601) can accommodate both NTSC and PAL systems as the encoding regulation of the studio for digitalizing the current color TV broadcast.

The CCIR recommendation specifies the picture size (luminance and chrominance signal), sampling method, frequency and coding method.

The color difference signal is subsampled only horizontally because it is easy to interpolate.

The luminance signal of the CCIR 601 screen has a coding unit of 720 * 480, and the color difference signals C _R and C _B are 360 × 480, and the number of pixels is 4: 2: 2, which is 4: 2: 2 format. do.

FIG. 1 is an input signal form of one conventional camera, and the sub-sampler 11 subsamples the color difference signals C _R and C _B from the CCIR601 format 4: 2: 2 element signal to 6.75 MHz. 4: 1: 1 signal.

At this time, the subsampled signal structure of 4: 1: 1 is shown in FIG. 2, and the luminance signal has a distance between pixels output to the DVCR 12 at 13.5MHz, and the color difference signals C _R and C _B are respectively 3.375MHz. do.

In the entire screen pixel configuration in one frame, the luminance signal is 720x480 as shown in FIG. 3, and the color difference signals C _R and C _B are 360x480.

When the compressed signal is input to the DVCR 12, the DVCR 12 records the input image on each tape.

Then, during monitoring, the display is performed on each monitor or on one monitor in the order A → B → C → D ... in order.

Alternatively, if multiple, for example, four surveillance cameras are recorded, four screens may be divided and displayed on one monitor, where only some of the projections (for example, one quarter) inputted on the screen of each camera are displayed.

Therefore, when displaying on each monitor as described above, it is difficult for one person to monitor at the same time, it is easy to miss the non-displayed portion when displaying with changing the order of display on one monitor, monitor multiple screens In the case of displaying at the same time, only a part of the recorded image is displayed, so there is a problem in that the area of the remaining non-display cannot be monitored.

As described above, there is a problem in that a surveillance function is not properly performed when capturing a plurality of areas with a plurality of surveillance cameras.

The present invention is to solve the above problems, an object of the present invention is a plurality of surveillance cameras or images from a plurality of signal input channels transmitted from a closed TV (CCTV) or cable TV (CATV) in one frame The present invention provides a multi-signal recording and reproducing apparatus which is configured by a plurality of divided screens and recorded according to the DVCR format so that a plurality of divided screens are all displayed on one monitor during monitoring.

It is another object of the present invention to provide a multi-signal recording and reproducing apparatus which records images from each camera or a plurality of signal input channels in one frame according to a DVCR format, and enables simultaneous display on a plurality of divided screens during playback. Is in.

A feature of the multi-signal recording and reproducing apparatus according to the present invention for achieving the above object is a signal input unit for outputting a plurality of video signals, a synchronous control unit for controlling the output of the signal input unit, and is output from the signal input unit A subsampling unit for subsampling the luminance signals and the chrominance signals of the plurality of video signals, respectively, a storage unit for temporarily storing the plurality of luminance signals and the chrominance signals subsampled by the subsampling unit, and a write signal in the storage unit; And a memory controller for outputting a read signal, a switching unit for outputting a luminance signal and a color difference signal read from the storage unit by switching, and a recording for recording and reproducing the luminance signal and the color difference signal output from the switching unit on a tape. It consists of a reproducing unit.

According to another aspect of the present invention, there is provided a multi-signal recording / reproducing apparatus, including: a signal input unit for subsampling and outputting a plurality of video signals, and a synchronous control unit for controlling the signal input unit so that the output of the signal input unit is sequentially output at a predetermined time interval. And a buffer for storing the luminance signal and the color difference signal output from the signal input unit, and a recording / reproducing unit for recording and reproducing the luminance signal and the color difference signal respectively output from the buffer.

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

FIG. 4 is a diagram showing the input signal form of one camera in the multi-signal recording and reproducing apparatus according to the present invention. FIG. 4a is for extracting data in the vertical direction on a line-by-line basis. Signal and 6.75 MHz color difference signals (C _R , C _B ) are subsampled by subsampler 41 to obtain a 6.75 MHz luminance signal, which is one-quarter of the input signal, and a 3.375 MHz color difference signals (C _R , C _B ). Output is shown.

4b extracts data in the vertical direction by selecting only one field in one frame. The luminance signal is 6.75 MHz and the chrominance signals C _R and C _B are respectively 3.375 MHz by subsampling inside the camera. is output as the output luminance signal is 6.75MHz, and the color difference signal C _R, and C _B is 1/4 of the color difference signal of a sub-sampled input signal in a sub-sampler 42 which is controlled so that of the 3.375MHz C _R, C _B is output at 3.375MHz.

5 is a diagram showing a configuration of a signal subsampled by a quarter of an input signal of one camera according to the present invention. The luminance signal has a 6.75 MHz interval between transmitted pixels, and a color difference signal (C _R ,). C _B ) is 1.6875 MHz between pixels to be transmitted.

In this case, FIG. 5A illustrates a configuration of a signal compressed by 1/2 each horizontally and vertically with respect to the input luminance signal as shown in FIG. 2A. Data extraction in the vertical direction is performed for each line.

FIG. 5B shows the configuration of a signal compressed by ½, horizontally and vertically, with respect to the input color difference signal as shown in FIG. 2B, and extracting data vertically is performed line by line.

In this way, in one frame pixel configuration obtained with one camera, the luminance signal is 360x240, and the color difference signals C _R and C _B are 180x240 as shown in FIG.

If A, B, C, D and 4 video signals inputted from four cameras are subsampled as shown in FIG. 4, respectively, to configure four screens obtained as shown in FIG. The luminance signals of the video signals obtained from the C and D cameras are called Ya, Yb, Yc, and Yd, respectively, and the color difference signals are C _R a, C _R b, C _R c, C _R d and C _B a and C _{B, respectively.} b, C _B c, and C _B d may form pixels of one screen as shown in FIGS. 7A to 7C.

In this case, in order to record four screens of one frame as shown in FIG. 7 on one tape, a luminance signal as shown in FIG.

Color difference signals C _R and C _{B as} shown in FIG.

It must be entered in order.

At this time, in the luminance signals Yx, i, j and the color difference signals Cx i, j, x is a, b, c, d screen, i is a horizontal pixel position, and j is a vertical pixel position.

The luminance signal Yx i, j and the color difference signal Cx i, j input as described above are processed according to the DVCR format.

In the DVCR format, compression is performed by a discrete cosine transform (hereinafter referred to as DCT) and variable length coding (VLC). The basic structure of the DCT has an 8 × 8 DCT block.

Therefore, the luminance signal Y has the 8,8 DCT blocks independently of the A, B, C, and D images in the above structure.

However, in the case of the color difference signals C _R and C _B , DCT is performed with the last two lines of A and C along with 6 lines of B and D, respectively, and the compression efficiency is lowered.

The influence of this time is that the AC coefficient increases in the DCT coefficient, so that the length of the code may be long when VLC is performed.

Since the VLC is performed on a screen composed of four different images divided into one screen such as A, B, C, and D, the efficiency of the VLC is increased.

As described above, when the luminance signals Yx i, j and the color difference signals Cx i, j are input, the structure in which one frame is recorded on the track on the tape is shown in FIG.

That is, the video segment portion of each track is recorded in half with A, B, C and D, respectively.

This structure has an easy structure at the time of editing.

When the tape recorded on the DVCR 51 is played back as shown in the eighth drawing, four screens A, B, C, and D divided by the ninth drawing are displayed on one monitor 52 at the same time. do.

At this time, the signal displayed on each of the divided screens is a signal obtained by compressing the original signal to ¼, and all the images input to each camera are displayed even if the image quality is slightly reduced by the compression.

10 is a block diagram of a multi-signal recording and reproducing apparatus according to the present invention, in which a signal input unit 61 composed of a plurality of cameras 61-1 to 61-4 is synchronized to control the output of the signal input unit 61. A control unit 61-5, a subsampling unit 62 for subsampling a plurality of luminance signals and a color difference signal output from the signal input unit 61, and a plurality of luminance signals subsampled by the subsampling unit 62; And a memory 63 for temporarily storing the color difference signals, a memory controller 64 for outputting a write signal and a read signal to the storage 63, and the luminance read from the storage 63 by switching. And a switching unit 65 for outputting a signal and a color difference signal, and a DVCR 66 for recording and reproducing the luminance signal and the color difference signal output from the switching unit 65 on a tape.

In this case, the subsampling unit 62 subsamples the luminance signal and the color difference signal of the first image output from the camera A 61-1 of the signal input unit 61, respectively. C of the subsampler 62-3. 62-4 signal input unit 61 for subsampling the luminance signal and the color difference signal of the second image output from the B camera 61-2 of the signal input unit 61, respectively. In the subsamplers 62-5 and 62-6 for subsampling the luminance signal and the chrominance signal of the third image output from the camera 61-3, and the D camera 61-4 of the signal input unit 61, respectively. And subsamplers 62-7 and 62-8 for subsampling the luminance signal and the chrominance signal of the fourth image to be output.

The storage unit 63 stores the outputs of the subsamplers 62-1, 62-3, 62-5, and 62-7 which subsamples the luminance signal among the first to fourth video signals. RAMs 63-1, 63-3, 63-5, and 63-7 having a storage capacity of 1, and subsamplers 62-2, 62-4, and 62 for subsampling a color difference signal among the first to fourth video signals. And rams 63-2, 63-4, 63-6, and 63-8 having a storage capacity of 240 * 180 to store the output of -6 and 62-8, respectively.

The switching unit 65 includes: a first switching unit 65-1 for selectively outputting one luminance signal among a plurality of luminance signals; and a second switching unit 65-2 for selectively outputting one color difference signal among a plurality of color difference signals; It is composed of

In FIG. 10 configured as described above, the luminance signal and the color difference signal output from each of the cameras 61-1 and 61-4 of the signal input unit 61 are subsampled by the respective subsamplers 62-1 to 62-8. As shown in FIG. 4, the subsampling process extracts pixels horizontally and vertically by 1/2, and pixel extraction in the vertical direction is performed on a line-by-line basis for odd and even fields.

In other words, when sub-sampling the luminance signal (Y) of 13.5MHz if the luminance signal (Y) output of 6.75MHz and each sub-samples the color difference signals C _R and C _B chrominance signal of 6.57MHz of 3.375MHz (C _R, C _B ) Is output.

The 6.75 MHz luminance signal Y output from the subsamplers 62-1, 62-3, 62-5, and 62-7 subsampling the luminance signal is applied to the write signal output from the memory controller 64. Subsamplers 62-2, 62-4, and 62 respectively stored in the RAMs 63-1, 63-3, 63-5, and 63-7 having a storage capacity of 240 x 360, and subsampling the chrominance signal. The color difference signals C _R and C _B of 3.375 MHz output from the -6 and 62-8 are RAMs 63-2 and 63 having a storage capacity of 240 × 180 by the write signal output from the memory controller 64. -4, 63-6, 63-8).

Here, the storage unit 630 is necessary because the pixel extraction in the vertical direction is performed in units of lines.

At this time, the memory controller 64 outputs read signals to the RAMs 63-1 to 63-4 in which the luminance and chrominance signals of the first and second image signals are stored for recording the first and second image signals. The first and second video signals written to the RAMs 63-1 to 63-4, and the luminances and chrominance signals of the third and fourth video signals are stored. 8) a write signal is output to write the third and fourth video signals subsampled by the subsamplers 62-5 to 62-8 to the RAMs 63-5 to 63-8.

The first and second switching units 65-1 and 65-2 alternately switch terminals a and b to output luminance signals of the first and second image signals A and B output through the a and b terminals. The color difference signal is recorded via the DVCR 66.

Therefore, the first and second video signals A and B are displayed at the top of the screen as shown in FIG. 9 during playback.

After the recording of the first and second video signals is completed, the memory controller 64 stores the RAMs 63-1 to 63-4 in which the luminance and chrominance signals of the first and second video signals are stored. Outputs the write signal to write the first and second video signals sub-sampled by the subsamplers 62-1 to 62-4 to the RAMs 63-1 to 63-4, and then to the third and fourth video signals. The RAM 63-5 to 63-8, which stores the luminance and chrominance signals, outputs a read signal to read the third and fourth image signals written to the RAM 63-5 to 63-8.

The first and second switching units 65-1 and 65-2 alternately switch the c and d terminals, and the luminance and the color difference of the third and fourth image signals C and D output through the c and d terminals. The signal is recorded via the DVCR 66.

Accordingly, the third and fourth image signals C and D are displayed at the bottom of the screen as shown in FIG. 9 during playback.

In this case, when it is desired to perform a zooming function for viewing one camera image on one screen, assuming that the video signal to be viewed is the first video signal, the luminance control and the color difference signal of the first video signal are determined by the memory controller 64. The read signals of the RAMs 63-1 and 63-2 to be recorded may be four times faster than the write signals.

Alternatively, when the luminance signal and the color difference signal of the first image signal output from the DVCR 66 are stored in the memory as shown in FIG. Can be done.

On the other hand, FIG. 12 is a signal form for compressing the input image from each camera by 1/2 each horizontally and vertically, and extracting the odd field or even field in one frame and compressing it by half. As another embodiment of the present invention shown, an even field is extracted.

In FIG. 12, since only one field is taken in one frame, the memory used in the process of generating the DVCR input signal can be eliminated.

A block diagram of a multi-channel recording and reproducing apparatus for recording a plurality of video signals extracted as in the thirteenth or the twelfth diagram, which is composed of a plurality of cameras and sequentially outputs a plurality of video signals by subsampling at predetermined time intervals. The signal input unit 71 to control the signal input unit 71 so that the output of the signal input unit 71 is sequentially output at a predetermined time interval, and the luminance signal output from the signal input unit 71. A line buffer 73 having a storage capacity of 1 × 720, a line buffer 74 having a storage capacity of 1 × 360 for storing a color difference signal output from the signal input unit 71, and the line buffer And a DVCR 75 for recording and reproducing the luminance signal Y and the color difference signals C _R and C _B output from the 73 and 74.

The synchronous control unit 72 delays the output of the synchronous signal generator 72-1 and the synchronous signal generator 72-1 by generating a synchronous signal and outputting it to the A camera 71-1. One clock delay unit 72-2 for outputting to the B camera 71-2, and one field delay for outputting to the C camera 71-3 by delaying the output of the synchronization signal generator 72-1 by one field. And a one-clock delay unit 72-4 which delays the output of the one-field delay unit 72-3 by one clock and outputs it to the D camera 71-4.

In FIG. 13 configured as described above, the synchronization signal generation unit 72-1 of the synchronization control unit 72 generates the synchronization signal to generate the A camera 71-1, the one clock delay unit 72-1, and the one field delay unit ( 72-3).

The one clock delay unit 72-1 delays the synchronization signal by one clock and outputs it to the B camera 71-2, and the one field delay unit 72-3 delays the synchronization signal by one field to the C camera 71. And -1) to the one-clock delay unit 72-4.

The one clock delay unit 72-4 delays the synchronization signal delayed by one field by the one field delay unit 72-3 by one clock and outputs it to the D camera 71-4.

As such, the first to fourth image signals output from the cameras 71-1 to 71-4 of the signal input unit 71 are sequentially output with time differences, so that no separate memory is required.

However, since the first and second video signals are output at a time interval of one clock, the luminance signals and the color difference signals of the first and second video signals are input to the line buffers 73 and 74 in the A and B order. After that, the first and second video signals need to be recorded at the read / write timings of A and B, so only a buffer of 1H is required.

Since the third and fourth video signals are also output at a time interval of one clock, after the recording of the first and second video signals is completed, the DVCR 75 undergoes the same process as the first and second video signal recording. If only the 1H buffer is needed.

That is, the inputs and outputs of the line buffers 73 and 74 have a time interval of 1H.

On the other hand, the present invention can be replaced by a multi-channel signal input unit for receiving a plurality of channel signals output from the CCTV or CATV signal consisting of a plurality of cameras.

That is, the plurality of cameras may be replaced by a plurality of receivers that receive a plurality of channels output from a broadcasting system such as CCTV, CATV, and the like.

Therefore, not only simultaneous recording and reproducing of a plurality of video signals output from multiple cameras of the multi-signal recording and reproducing apparatus of the present invention, but also simultaneous recording and reproducing of a plurality of channel signals output from a broadcasting system such as CCTV or CATV can be performed. .

As described above, according to the multi-channel recording and reproducing apparatus according to the present invention, a plurality of video signals transmitted from a plurality of surveillance cameras or broadcasting systems such as CCTV or CATV are composed of a plurality of divided screens in one frame, and then a DVCR format. By recording in accordance with the present invention, a plurality of divided screens are all displayed on one monitor during monitoring and playback, thereby enabling simultaneous viewing and monitoring of a plurality of video signals.

Claims (11)

A signal input unit for outputting a plurality of video signals, a synchronous control unit for controlling the output of the signal input unit, a subsampling unit for subsampling luminance signals and color difference signals of the plurality of video signals output from the signal input unit, respectively; A storage unit for temporarily storing a plurality of luminance signals and color difference signals sub-sampled by the sub-sampling unit, a memory controller for outputting a write signal and a read signal to the storage unit, and a luminance signal read from the storage unit by switching And a switching unit for selectively outputting a color difference signal, and a recording and reproducing unit for recording and reproducing the luminance signal and the color difference signal output from the switching unit on a tape. The multi-signal recording and reproducing apparatus according to claim 1, wherein the signal input unit is composed of a plurality of cameras. The multi-signal recording and reproducing apparatus according to claim 1, wherein the signal input unit comprises a plurality of receivers each receiving a plurality of broadcast signals. The multi-signal recording and reproducing apparatus according to claim 1, wherein the subsampling unit performs vertical subsampling of luminance and chrominance signals on a line basis. The multi-signal recording and reproducing apparatus according to claim 1, wherein the storage unit for storing the plurality of luminance and chrominance signals respectively has a capacity for storing the luminance signal and the chrominance signal of one screen among the divided plurality of screens. . A signal input unit for subsampling and outputting a plurality of video signals, a synchronous control unit controlling the signal input unit to sequentially output the signal input unit at predetermined time intervals, and a luminance signal and a color difference signal output from the signal input unit. And a recording / reproducing unit for recording and reproducing a luminance signal and a color difference signal respectively output from the buffer. 7. The multi-signal recording and reproducing apparatus according to claim 6, wherein the signal input unit comprises a plurality of cameras. 7. The multi-signal recording and reproducing apparatus according to claim 6, wherein the signal input unit comprises a plurality of receivers each receiving a plurality of broadcast signals. 7. The multi-signal recording and reproducing apparatus according to claim 6, wherein the signal input unit selects only one field data in one frame during vertical subsampling of the luminance and chrominance signals. The display apparatus of claim 6, wherein the first and second video signals and the third and fourth video signals of the signal input unit are output at a time interval of one field under the control of the synchronization controller, and the first and second video signals are outputted. And a video signal is output at a time interval of one clock, and the third video signal and a fourth video signal are also output at a time interval of one clock. The method of claim 6, wherein the buffer comprises a line buffer having a capacity for storing only one horizontal section of the luminance signal and the chrominance signal of the plurality of video signals output at predetermined time intervals from the signal input unit, respectively. Multi-signal recording and reproducing apparatus.