JPH11289513A - Video recording and reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the video recording and reproducing device that reproduces desired video recording data through a high speed search without interrupting the recording during video recording and discriminates undesired video recording data among the video recording data having already been recorded and manages the data such as delete of the undesired video recording data. SOLUTION: The video recording and reproducing device is provide with a video recording block 102 that outputs difference data between a current frame where compression processing is applied to video information and one preceding frame as the video recording date, a main memory 105 that stores a prescribed amount of video recording data, a timer 106 that provides time information used for management of time information added to the video recording data and a storage period of the video recording data, a hard disk drive 107 that records the video recording data with recording management information added thereto to a recording medium, reproduces the video recording data on a reproduction request and deletes the video recording data whose storage period is expired, a reproduction block 103 that applies expansion processing to the reproduced video recording data and provides an output of the result as video information, and a CPU 104 that adds time information to recording management information of the video recording data, transfers the result to the main memory 105, monitors the time information of the recorded video recording data and the timer 106 and deletes the video recording data whose storage period is expired based on the difference data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video recording / reproducing apparatus capable of recording and reproducing video for a long time.

[0002]

2. Description of the Related Art Conventionally, in a store, a cash dispenser, a warehouse, or the like, an image of the place can be recorded for a long time as a surveillance system for crime prevention, and the image can be reproduced. Video recording / reproducing device is installed. The video recording / reproducing apparatus records video captured by a surveillance camera on a video cassette tape for a long time.

FIG. 8 is a schematic diagram showing a schematic configuration of a conventional video recording / reproducing apparatus. 8, a video recording / reproducing device 801 includes a sync separation circuit 802, a servo controller 803, a recording block 804, a reproduction block 805, a switching unit 806, a drum head 807, and a pinch roller 80.
8. A capstan 809 is provided. Recording block 8
04 is a YC separation circuit 810, a frequency modulation circuit 811,
An adder 812, a recording amplifier 813, and a switch 814 are provided. The reproduction block 805 includes the reproduction amplifier 81
5. High pass filter (HPF) 8
16. Low pass filter (LPF)
817, a frequency demodulation circuit 818, and an adder 819. The recording medium for recording the video is a video cassette tape 820.

[0004] In FIG. 8, when a video captured by a surveillance camera is input to a video recording / reproducing device 801, a video signal is transmitted to a YC separation circuit 8 of a recording block 804.
The Y signal is separated by YC into a frequency modulation circuit 8.
The signal is frequency-modulated at 11 and added to the C signal at the adder 812. This signal is amplified by the recording amplifier 813,
The data is recorded on the video cassette tape 820 by the drum head 807 via the switch unit 814 and the switching unit 806 in a helical scan system. At this time, the spindle controller of the drum head 807 and the pinch roller 80 are controlled by the servo controller 803 based on the synchronization signal separated from the input video signal by the synchronization separation circuit 802.
8. The control of the capstan 809 and the rotation control of the tape reel are performed.

When reproducing recorded video information, a video signal read from the video cassette tape 820 by the drum head 807 passes through the switching unit 806 and is input to the reproduction block 805 to be reproduced by the reproduction amplifier 815.
After that, the signal is separated into a Y signal component and a C signal component by the HPF 816 and the LPF 817. The Y signal component is demodulated by a frequency demodulation circuit 818, and is added to an adder 819.
, And is added to the C signal component and output as a reproduction signal.

In the case of a video recording / reproducing apparatus used in such a monitoring system, a long-time video signal must be recorded. Therefore, in the conventional video recording / reproducing apparatus, in order to increase the recording time, the switch unit shown in the figure is turned on once every several tens of frames, and the circuit such as the capstan is controlled to record one frame per second. Recording is performed by dropping frames, such as recording one frame every five seconds.

[0007] In a normal pause state, the switch unit and the rotary drive system are controlled by an external sensor such as an infrared sensor, so that an image is recorded when any change occurs in a place where a picture is taken. In some cases.

[0008]

However, in the above-described video recording / reproducing apparatus, when recording data already recorded is reproduced from the tape medium during recording of the recording data, the recording operation is temporarily stopped. However, there is a drawback that the required video cannot be recorded.

If the number of dropped frames is increased in order to increase the recording time, a rapid change in the movement may be missed. Conversely, if the number of dropped frames is reduced so as not to miss a rapid change in motion, there is a disadvantage that the recording time on one recording medium is shortened and the number of exchanges of the recording medium (tape medium) is increased.

According to the present invention, desired recorded data can be reproduced by a high-speed search without interrupting the recording operation during recording, and unnecessary recorded data is discriminated from already recorded recorded data. It is another object of the present invention to provide a video recording / reproducing apparatus capable of performing data management such as deleting unnecessary recording data.

[0011]

Therefore, according to the present invention, there is provided the present invention, wherein difference data between a current frame of compressed data obtained by performing a compression process on input video information and a frame immediately before the current frame is obtained. , A main memory for storing a fixed amount of recording data transferred from the recording block, time information in recording management information added to the recording data, and time information used for managing a storage period of the recording data. A hard disk drive that records recorded data to which recording management information is added, records the recorded data on a recording medium, reproduces the recorded data based on a reproduction request, and deletes the recorded data whose storage period has elapsed. A playback block that performs decompression processing on recorded data transferred from the The time information from the timer is added to the recording management information and transferred to the main memory, and the time information in the recording management information of the recording data recorded on the hard disk drive and the time information from the timer are added to the read recording data. And a CPU for controlling the deletion of recorded data whose storage period has elapsed based on the difference data.

The present invention according to claim 2 provides the invention according to claim 1.
In the video recording / reproducing apparatus described above, the CPU changes the storage period of the recorded data based on the difference data.

Further, the present invention described in claim 3 is based on claim 1.
In the video recording / reproducing device described in the above items 2 and 2, the storage period is
It is characterized in that the storage periods of adjacent frames are different.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the video recording / reproducing apparatus according to the present invention will be described. FIG. 1 is a schematic diagram showing a schematic configuration of an embodiment of a video recording / reproducing apparatus according to the present invention. FIG.
FIG. 3 is a schematic diagram for explaining difference data in the video recording / reproducing device of the present embodiment. 1, a video recording / reproducing apparatus 101 includes a recording block 102, a reproducing block 103, a CPU 104, a main memory 105, a timer 1
06 and a hard disk drive 107.

As shown in FIG. 1, a plurality of recording blocks are provided, and each recording block is connected to a plurality of photographing cameras one by one. The recording block is an analog / digital (A / D: Analog / Digital) converter 1
08, NTSC decoder 109, image compressor 110, frame memory 111, FIFO (First In First Out)
A memory 112 is provided.

The A / D converter 108 converts an analog video signal input from the photographing camera into a digital signal.

NTSC (National Television System C)
ommittee) decoder 109 separates the composite digital signal from the A / D converter 108 into a luminance (Y) signal and a chrominance (C) signal, and color-demodulates the color signal to produce two color difference signals (Cb, Cr). And outputs it together with the luminance signal (Y).

The image compressor 110 writes the input video signals (Y, Cb, Cr) in the frame memory 111 and performs image compression processing on the video signals written in the frame memory 111 in block units (8 × 8). And writing to the frame memory 111 is performed again. At the same time, as shown in FIG. 2, a difference from the data one frame before is calculated to generate difference data, and the difference data is written to the frame memory 111. When the compressed data and the difference data for each block are stored in the frame memory for one frame by these processes, they are transferred to the FIFO memory 112. Here, the video recording / reproducing apparatus of this embodiment is a JPEG (Joint Photogra
phic cording Experts Group) or MPEG
(Moving Picture Experts Group) method is used.

The frame memory 111 stores the image compressor 11
A first memory (not shown) for writing video signals (Y, Cb, Cr) input to 0, and a second memory (not shown) for writing compressed data subjected to image compression processing and difference data. It has.

The FIFO memory 112 stores the image compressor 11
Recorded data including compressed data and difference data output from 0 is temporarily stored, and the recorded data is transferred to the main memory 105 under the control of the CPU 104 described later.

The CPU 104 controls the FIFO memory 105 in each recording block in a time-division manner, reads one frame of recorded data, and transfers the data to the main memory 105. Further, the CPU 104 determines a correlation level for each frame of the recording data based on difference data of all block data in the frame, and stores recording management information such as a storage level, channel information, and time information from the timer 106 described later. Is added for each frame.

The CPU 104 monitors each storage level of the recording data recorded in the hard disk drive 107, deletes the recording data for which the storage period set as the storage level has elapsed, and replaces the recording data with the deleted part. Control is performed to overwrite newly input recording data.

The CPU 104 also controls the hard disk drive 1 based on an externally requested reproduction of the recorded data.
A control is performed to search for the recorded data in 07 and transfer the designated recorded data to a playback block 103 described later.

When a certain amount of recording data reaches a predetermined amount under the control of the CPU 104, the main memory 105 stores the hard disk drive 1 in a predetermined file format.
07.

The timer 106 provides time information in the recording management information added to the recording data, and also provides time information used when the hard disk drive 107 manages the storage period.

The hard disk drive 107 has a CPU
Under the control of 104, the recording data to which the recording management information transferred from the main memory 105 has been added is written to a recording medium in the hard disk drive 107, with the addition of directory information for managing each recording data as a file. And save the recorded data.

Further, under the control of the CPU 104, the recorded data is deleted by deleting the recorded data for which the storage period set at the storage level has elapsed or the directory information of each frame. Further, under the control of the CPU 104, the designated recording data is reproduced and output to the reproduction block 103.

In FIG. 1, the reproduction block 103
An IFO memory 113, an image decompressor 114, a frame memory 115, an NTSC encoder 116, and a digital / analog (D / A: Digital / Analog) converter 117 are provided.

The FIFO memory 113 stores the recorded video data to be reproduced transferred under the control of the CPU 104.

The image decompressor 114 is provided in the FIFO memory 11
3 is stored in a temporary frame memory 11
5, the data is read from the frame memory 115 in block units, subjected to image decompression processing, and output to the NTSC encoder 116 as reproduction data.

The frame memory 115 temporarily writes the recording data from the FIFO memory 113.

The NTSC encoder 116 performs color modulation on the reproduced data from the image expander 114, converts the reproduced data into a composite digital signal, and outputs the composite digital signal.

Digital / Analog (D / A: Digital / A
nalog) The converter 117 is an NTSC encoder 11
6 is converted into an analog signal and output as video information.

The recording operation will be described. In FIG. 1, the recording block 102 includes channels 1 to n (C
H: Channel) are connected, and images captured by the respective monitoring cameras are input as input signals. The input video signal is supplied to the A / D converter 108
Is converted from an analog signal to a digital signal, and then input to the NTSC decoder 109.

The digital signal (composite) input to the NTSC decoder 109 is separated into a luminance signal (Y signal) and a chrominance signal (C signal), and the chrominance signal is color-demodulated into two color difference signals Cb and Cr. It is converted and output to the image compressor 110 together with the luminance signal.

The image compressor 110 writes the input video signal (Y, Cb, Cr) in the first memory of the frame memory 111, reads the video signal from the first memory, and
A compression process is performed for each block unit and the frame memory 111
At the same time, the difference between the current frame and the frame one frame before the current frame is calculated to generate difference data, and the difference data is written to the second memory of the frame memory 111. By these processes, the compressed data for each block and the difference data for one frame are stored in the frame memory 1.
When the data is stored in the memory 11, it is transferred to the FIFO memory 112 as recording data including compressed data and difference data.

The CPU 104 accesses the FIFO memory 112 in each recording block in a time-division manner, reads out one frame of recorded data stored in the FIFO memory 112, and transfers it to the main memory 105. At this time, C
The PU 104 determines, for each frame of the recorded data, the correlation level based on the difference data of all the block data in the frame, and records the recording management information such as the storage level, the channel number information, and the date and time information from the timer for each frame data. To be added.

When the amount of data in the main memory 105 reaches a certain amount, under the control of the CPU 104, the recorded data is stored in a predetermined file format in the hard disk drive 1.
07 and written to a recording medium in the hard disk drive 107. At this time, directory information for managing the recording data as a file is also written. Thus, the recording of the recording data is performed.

Next, the reproducing operation will be described. In FIG. 1, when there is a request to reproduce recorded data recorded based on channel number and date and time information, the CPU
104 searches the hard disk drive 107 based on the channel number and the date and time information during the transfer of the recorded data from the recording blocks 102 of 1 to n channels, and reads out the desired recorded data from the hard disk drive 107.

The read recorded data is transferred to the FIFO memory 113 of the reproduction block 103. FIFO
The recorded data stored in the memory 113 is stored in the image expander 11.
4 to the frame memory 115. The image decompressor 114 reads out data from the freem memory 115 in block units, performs image decompression processing, and outputs the reproduced data to the NTSC encoder 116.

The NTSC encoder 116 performs color modulation, converts it into a composite digital signal, and outputs it to the D / A converter 117. The D / A converter 117 converts a digital signal into an analog signal and outputs it as video information.

Next, a process of managing recorded data recorded on the recording medium of the hard disk drive 107 will be described. First, the storage level of recorded data will be described. Here, it is assumed that the video information has been compression-encoded by the JPEG method. FIG. 3 is a schematic diagram for explaining a storage level added to recorded data in the video recording / reproducing apparatus of the present embodiment. In FIG. 3, the storage level of the recorded data indicates the time from the time of recording to the time when the recorded data recorded on the hard disk drive is deleted. The storage levels are, for example, from level A to level I,
From the level A to the level I, the recording data storage period is set to be shorter. The CPU 104 in FIG. 1 refers to the timer 106, monitors the storage level of each recording data, and deletes the recording data after a predetermined period has passed.

For example, at level I, after six hours have elapsed from the time of recording, the recorded data is automatically deleted from the recording medium in the hard disk drive 107. Level B
Saves the recorded data in the hard disk drive 107 for three months from the time of recording, and permanently saves the recorded data in the hard disk drive 107 in the case of level A. In other words, the level A is a level at which recording data deletion processing cannot be performed in recording data management described later.

Next, how the storage level of the recording data described above is added to the input recording data will be described. FIG. 4 is a schematic diagram for explaining the addition of the storage level of the recorded data in the video recording / reproducing apparatus of the present embodiment. In FIG. 4, in the initial state, the order of the storage levels added to each frame of the recording data is set in advance, and the storage levels are added to each frame according to the order. This initial state is a case where the above-described difference data is not detected and a case where it is determined that the input recorded data is a still image.

In FIG. 4, in the initial state, the highest storage level is set to level E (3 days), the lowest storage level is set to level I (6 hours), and the levels E, F, G,
H and I are set. The storage level in the initial state is, for example, such that the number of level H frames one level higher than the number of level I frames is １ ／. That is, in FIG. 4, out of the 16 frames from the level E frame to the next level E frame, the level I is 8 frames, the level H is 4 frames, the level G is 2 frames, the level F is 1 frame, and the level E is 1 frame. It becomes a frame.

The arrangement order of the storage levels is such that a frame of the next storage level F is arranged between frames of the highest storage level E in the initial state, and a frame of the level E, a frame of the level F, and a frame of the level F are arranged. Frames of level G are arranged between frames of level E, and similarly, frames of lower levels are arranged between frames of different levels.

By recording the recorded data in the order and arrangement of the storage levels as described above, when the recorded data is reproduced, the image information becomes an image in which frames are deleted on average, and a video of a certain time is skipped. Video information.

For example, in FIG. 4, when the recorded data is deleted from frame N + 1 to frame N + 5 in the order of frames N + 2, N + 3,..., In the case of reproduction, reproduction is performed in the order of frame N, frames N + 6, N + 7,. As a result, the image is lost on the way. But,
According to the above-described deletion method of the present embodiment, the recorded data is
In order to delete frames N + 1, N + 3, N + 5... In the case of reproduction, frames N, N + 2, N + 4,
Reproduction is performed in the order of N + 6. Therefore,
The video information is reproduced in a frame-dropped state because the video in the middle is not deleted collectively.

The video recording / reproducing apparatus according to the present embodiment can use the MPEG system for the compression encoding of video information. FIG. 5 is a schematic diagram for explaining the addition of the storage level to the recording data that has been subjected to the compression and encoding processing of the MPEG system in the video recording and reproducing apparatus of the present embodiment. In the compression coding process of the MPEG system, video information is obtained by combining an intra-coded I picture, a P picture predicted and coded using the correlation between the preceding frame, and both the front and rear frames. There are B pictures that are predictively coded using correlation, and one I picture and a plurality of P pictures and B pictures constitute one group (GOP).

In FIG. 5, a frame of an intra-coded I picture is set to a high storage level E, a P picture predicted and coded by using a correlation with a preceding frame is set to a storage level F, , One of the B pictures is stored at a storage level G, and the other is at a storage level H.
And

As described above, the storage period is automatically set for each frame of the video information, and after a predetermined time has elapsed, the recording data is deleted from the hard disk in order from the frame having the lower storage level.

The method of adding the storage level described above is as follows.
This is a case where the difference data generated by the image compressor shown in FIG. 1 is not detected, that is, a case where there is no change in video information between frames. If difference data is detected, that is, if there is a change in video information between frames, the set storage level is converted according to the change in the video information.

Next, a case where difference data between frames is detected, that is, a case where there is a motion in a video being shot will be described. FIG. 6 is a schematic diagram for explaining the conversion of the storage level of the recorded data in the video recording / reproducing apparatus of the present embodiment. In FIG. 1, when the difference data generated by the image compressor 110 is transferred to the main memory 105 together with the recording data under the control of the CPU 104,
The CPU 104 monitors the difference data, and when the difference data is detected, converts the storage level to be added to the recorded data to a higher storage level and adds it.

That is, when the difference data is detected, it is judged that the image information is a change in the video data between frames, and that there is some change in the place where the monitoring camera is shooting. In order to save the change for a longer time, the storage level is converted to a higher storage level and added.

As shown in FIG. 6, in the initial state, when the storage level added to the recorded data is changed from level F to level I, for example, the level is converted from level D to level G by detecting the difference data. Further, in order to lengthen the interval at which recording data is deleted, the recording data may be converted into level A, level C, level E, and level G. As described above, when the difference data is detected, the storage level is converted to another storage level and added to the recording data, so that the recording data that has changed as the video information can be stored for a longer time.

Next, the process of deleting recorded data in the hard disk drive 107 performed by the CPU 104 will be described. FIG. 7 is a flowchart illustrating a process of deleting recorded data in the video recording / reproducing apparatus of the present embodiment. In FIG. 7, the CPU reads the recording management information of the hard disk drive at regular intervals (step 1). The storage period set at the storage level of each recording data in the recording management information is compared with the time information of the timer (step 2). If the time from the recording has not passed the expiration date, processing is performed on the next recorded data (step 3). If the expiration date has passed, the recorded data is invalidated on the hard disk drive with the directory information invalidated. (Step 4). The above processing is performed on all the recorded data recorded in the hard disk drive (step 5).

The CPU repeats the above-described processing at regular time intervals with reference to a timer. This allows
In the hard disk drive, the recording data whose storage period has elapsed is deleted, and the newly input recording data is overwritten.

As described above, in the video recording / reproducing apparatus according to the present embodiment, the period during which the recording data is stored in the hard disk drive is automatically set, and after a predetermined time has elapsed, the recording data is thinned out. Can be overwritten with new recording data,
More video information can be recorded on the hard disk drive.

In the above-described embodiment, a color image is recorded. However, the present invention is not limited to this, and a monochrome image may be recorded. In the case of black and white video, the amount of information is smaller than that of color video,
More images can be recorded on the hard disk drive.

[0060]

According to the present invention, desired recorded data can be reproduced by high-speed search without interrupting the recording operation during recording of a plurality of input video information. Further, it is possible to determine unnecessary recording data from the recording data already recorded, and manage the recording data for deleting the unnecessary recording data.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a schematic configuration of an embodiment of a video recording / reproducing apparatus of the present invention.

FIG. 2 is a schematic diagram for explaining difference data in the video recording / reproducing apparatus of the embodiment.

FIG. 3 is a schematic diagram for explaining a storage level added to recorded data in the video recording / reproducing apparatus of the present embodiment.

FIG. 4 is a schematic diagram for explaining addition of a storage level of recorded data in the video recording / reproducing apparatus of the embodiment.

FIG. 5 shows a video recording / reproducing apparatus according to the present embodiment.
It is a schematic diagram for demonstrating the addition of the preservation | save level to the recording data which carried out the compression encoding process of G system.

FIG. 6 is a schematic diagram for explaining conversion of a storage level of recorded data in the video recording / reproducing apparatus of the embodiment.

FIG. 7 is a flowchart showing a process of deleting recorded data in the video recording / reproducing apparatus of the embodiment.

FIG. 8 is a schematic diagram showing a schematic configuration of a conventional video recording / reproducing apparatus.

[Explanation of symbols]

101 video recording / reproducing device, 102 video recording block, 103 reproduction block, 104 CPU, 10
5. Main memory, 106 timer, 107 hard disk drive, 108 A / D converter,
109 NTSC decoder, 110 image compressor,
111 frame memory, 112 FIFO memory, 113 FIFO memory, 114 image expander, 115 frame memory, 116 NTSC encoder, 117 D / A converter 801 video recording / playback Device, 802 synchronization sync circuit, 803 servo controller, 804 recording block, 805
· Reproduction block, 806 ··· Switching unit, 807 ··· Drum head, 808 ··· Pinch roller, 809 ··· Capstan, 810 ··· YC separation circuit, 811 ··· Frequency modulation circuit, 812 ··· Addition unit, 813 ···・ Recording amplifier, 81
4. Switch section, 815 playback amplifier, 816
HPF, 817 LPF, 818 frequency demodulation circuit, 819 addition section, 820 video cassette tape

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI H04N 5/92 H04N 5/92 H 7/18

Claims (3)

[Claims] 1. A recording block for outputting, as recorded data, a difference between a current frame of compressed data obtained by performing compression processing on input video information and a frame immediately preceding the current frame as recorded data, A main memory for storing a fixed amount of the transferred recording data, a timer for providing time information in recording management information added to the recording data and time information used for managing a storage period of the recording data, and a recording management information A hard disk drive that records the recorded data added to the recording medium, reproduces the recorded data based on a reproduction request, and deletes the recorded data whose storage period has elapsed, and the recording transferred from the hard disk drive. A playback block that performs decompression processing on the data and outputs it as video information; The time information from the timer is added to the recording management information and transferred to the main memory, and the time in the recording management information of the recording data recorded on the hard disk drive is controlled. CP that monitors information and time information from the timer and controls to delete the recorded data whose storage period has elapsed based on the difference data.
A video recording / reproducing apparatus comprising a U (Central Processing Unit). 2. The video recording / reproducing apparatus according to claim 1, wherein the CPU changes a storage period of the recorded data based on the difference data. 3. The video recording / reproducing apparatus according to claim 1, wherein the storage period differs between adjacent frames.