JP2007027891A - Recording/reproducing device, recording/reproducing method, and computer program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To switch display without any breaks from time shift reproduction to live video reproduction in a monitoring recording/reproducing device. <P>SOLUTION: In the monitoring recording/reproducing device, an equipped RAM (high-speed random access memory) for alarm recording is utilized to control read from a hard disk drive and that from the RAM, thus switching the display without any additional costs and any breaks from the time shift reproduction to the live video reproduction. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a recording / playback apparatus, a recording / playback method, and a computer program, and more particularly to a technique suitable for use in time-shift playback of a monitoring video recording / playback apparatus using a network camera.

  In recent years, in television broadcasting, the received broadcast signal is converted into digital information and recorded on a large-capacity recording medium represented by a randomly accessible hard disk drive, while the recorded content is read out in parallel with the recording, and the video signal A video recording / reproducing apparatus having a so-called time shift reproduction function is provided.

  In the surveillance market, moving images and still images can be compressed and sent in a technique for sending a digital image taken by a camera unit to a monitoring recording / playback device or display device via a network such as a LAN or the Internet. This monitoring recording / playback apparatus generally has a time-shift playback function for playing back video at different times while recording on a randomly accessible storage medium. Proposals have been made to realize time-shifted reproduction with lower delay and higher image quality (see Patent Document 1).

  By the way, in a video recording / reproducing apparatus, there exists a high-speed reproduction function that reproduces a reproduction speed faster than a normal speed, for example, by about 1.2 to 1.5 times. This makes it possible to acquire information from an information program represented by a news program in a relatively short time. By combining the time-shift playback function and the high-speed playback function, it becomes possible to bring the viewing of the program that started to be viewed later than the scheduled time closer to the viewing by the broadcast distributed at the actual time.

JP 2004-220638 A

  However, an apparatus that immediately records the received video on the hard disk drive cannot switch from the time-shifted playback state to the video delivered at the actual time without creating a break, and once started viewing with time-shifted playback. The video can only be viewed with time-shifted video until the viewer operates.

  In view of the above-described problems, an object of the present invention is to enable a recording / reproducing apparatus to switch display without making a break from time shift reproduction to live video reproduction.

  In the present invention, video receiving means for receiving video information from the camera unit, a randomly accessible mass storage medium, recording means for recording video information received from the video receiving means on the mass storage medium, Reads the video information from the large-capacity storage medium and displays the video on the display unit, the time shift playback unit that simultaneously performs the recording unit and the playback unit in parallel, and starts processing using an event as a trigger A recording / reproducing apparatus comprising: an event trigger processing unit; an event recording unit for recording the event; a high-speed random-access pre-event video storage medium that holds a video before the event occurs for a predetermined period; and a timer. And the reproducing means receives the video data received by the mass storage medium and the pre-event video storage medium. When storing, it adds the time information obtained from the previous period timer, to provide a recording and reproducing apparatus or the like, characterized in that the selecting and reproducing one of the storage medium using the time information.

  According to the present invention, by using a RAM (high-speed random access memory) provided for alarm recording, the display can be switched without creating a break from time shift reproduction to live video reproduction.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.
A general monitoring recording / reproducing apparatus is also called a monitoring recorder, and records a specified frame of video from each camera unit per unit time. This recording is called time lapse recording. Also, conditions are set, an alarm event is generated when the conditions are met, and recording is performed at a higher frame rate than time-lapse recording. This is called alarm recording. Further, in alarm recording, there is a function of recording a video shot at a specified time immediately before an alarm event occurs at a frame rate equivalent to alarm recording. This is called pre-alarm recording. In pre-alarm recording, in order to record the time that has passed when the alarm event occurred, a memory to hold the video during that time is required, and usually a sufficient ring buffer is provided to hold the video for the specified time .

FIG. 1 is a diagram showing an example of the configuration of a monitoring recording / reproducing apparatus according to the first embodiment of the present invention.
In FIG. 1, 100 is a monitor recording / reproducing apparatus main body, 101 is a network interface for receiving video data transmitted from a camera unit described later, 102 is a CPU for controlling the monitor recording / reproducing apparatus 100, 103 is a control program, This is a read-only memory in which setting values are written, and a mass storage medium described later may be used.

  Reference numeral 105 denotes a memory capable of high-speed random access, which is used when the CPU 102 executes a control program and as a reception buffer for video data from the network interface 101.

  Reference numeral 105 denotes a large-capacity storage medium (HDD) represented by a randomly accessible hard disk drive, 106 a timer, 107 a decoder for decoding video data encoded by moving image compression, and 108 decoded video data. Is a pre-alarm buffer, and is a random access memory prepared to perform high-definition recording before an event alarm occurs when an event alarm occurs. It is composed of a ring buffer so that the passed video is overwritten.

  Reference numeral 120 denotes an image conversion processing unit (Frame Skipping) that performs processing for reducing the amount of received video data. The image conversion processing unit (Frame Skipping) 120 performs data processing such as frame thinning, image size change, image compression rate change, and moving image compression / decoding method change. The image processing is not limited to the above processing method as long as the image processing is performed in a small amount, and may be a combination of two or more types of the above processing.

  Reference numeral 150 denotes a camera unit represented by a network camera. The camera unit mainly includes an imaging unit, an AD conversion unit, a moving image compression / encoding unit, and a network interface (all not shown), and compresses the captured moving image as a moving image. Encode and send to the network. Reference numeral 160 denotes a display device represented by a television monitor or a personal computer monitor.

FIG. 2 is a flowchart showing a processing procedure during normal recording in the present embodiment.
When the processing is started, the video data transmitted from the camera unit 150 is received by the reception buffer 105 via the network interface 101 (step S201). Next, video data to be described later is read from the reception buffer as needed (step S202).

  First, as a first reading, reading for time-lapse recording is performed. The video data read for time-lapse recording is subjected to, for example, frame thinning processing in the image conversion processing unit 120 (step S203).

  Further, as a second readout, readout for pre-alarm recording is performed. The video data read out for pre-alarm recording is written together with time information obtained from the timer 106 at the end of the pre-alarm buffer constituted by a ring buffer (step S204). Then, the video data thinned out in step S203 is added to the time information obtained from the timer 106 and recorded on the mass storage medium 105 (step S205).

  Further, readout for video display is performed as the third readout. The video data read for video display is decoded by the decoder 107 from the video data that has been compressed and encoded by the camera unit, and is displayed on the display device 160 via the display driver 108.

  The video display includes a video (live video) currently captured by the camera unit and a video (time-shifted playback video) previously captured by the camera unit and stored in the monitoring recording / reproducing apparatus. Furthermore, there are two types of time-shifted playback video: video stored in the hard disk drive and video stored in the pre-alarm buffer, and playback starts based on the current time and the pre-alarm recording time. The storage medium to be read is switched according to time.

FIG. 3 is a flowchart showing a transition procedure from live video display or time shift playback video display to time shift playback video display in the present embodiment.
When the process is started, live video display or time shift reproduction using a pre-alarm buffer is first performed (step S301). Next, a pause (or rewinding and time setting) is performed (step S302). After that, when playback is performed, the time of playback for the paused time becomes an image of the past time (step S303). Also, when rewinding or past time designation is performed, the playback time becomes a video of the past time as in the case of temporary stop.

  Next, the playback start time is compared with the current time (step S304), and it is determined whether the time is within the pre-alarm recording time (step S305). If the result of this determination is that it is within the time, the video data from the designated time is read from the pre-alarm buffer with reference to the time information obtained from the timer 106 (step S306).

  On the other hand, if the result of the determination in step S305 indicates that the comparison result exceeds the pre-alarm recording time, the time information obtained from the hard disk drive from the timer 106 is referred to, and the video from the specified time is displayed. Data is read out (step S307). In either case, the read video data is decoded by the decoder 107 and displayed on the display device via the display driver 108.

  In time-shift playback, there is a playback process in which the playback speed is about 1.2 to 1.5 times faster than real-time playback. This is called high-speed playback. It is possible to increase the amount of information that can be recognized per unit time by performing playback at a higher speed than usual.

FIG. 4 is a flowchart showing processing procedures such as high-speed playback and fast-forward during time-shift playback in the present embodiment.
First, time shift reproduction is performed to read video data from the hard disk drive (step S401).

  Next, when the start time is designated and playback is performed at a higher speed than the real-time playback by high-speed playback (step S402), the playback time approaches the current time. Then, as described with reference to FIG. 3, the reproduction time is compared with the current time (step S403). Next, it is determined whether it is within the pre-alarm recording time (step S404).

  If the result of this determination is that it is within the time, reading of video data from the hard disk drive is stopped (step S405), and video data is read from the pre-alarm buffer (step S406). If it is still outside the pre-alarm recording time range, the process returns to step S403 to continue reading the video data from the hard disk drive, and periodically compare the reproduction time with the current time.

  By performing the processing as described above in the monitoring recording / reproducing apparatus and switching the reading from the large-capacity storage medium and the pre-alarm buffer, it is possible not only to smoothly switch to the video display but also to use the high-definition video as much as possible. Monitoring can be performed.

(Another embodiment according to the present invention)
Each means constituting the recording / reproducing apparatus and each step of the recording / reproducing method in the embodiment of the present invention described above can be realized by operating a program stored in a RAM or ROM of a computer. This program and a computer-readable recording medium recording the program are included in the present invention.

  Further, the present invention can be implemented as, for example, a system, apparatus, method, program, or recording medium, and can be applied to a system composed of a plurality of devices. Moreover, you may apply to the apparatus which consists of one apparatus.

  In the present invention, a software program (in the embodiment, a program corresponding to the flowcharts shown in FIGS. 2 to 4) for realizing the functions of the above-described embodiments is directly or remotely supplied to a system or apparatus, This includes the case where the system or apparatus computer also achieves by reading and executing the supplied program code.

  Accordingly, since the functions of the present invention are implemented by computer, the program code installed in the computer also implements the present invention. In other words, the present invention includes a computer program itself for realizing the functional processing of the present invention.

  In that case, as long as it has the function of a program, it may be in the form of object code, a program executed by an interpreter, script data supplied to the OS, and the like.

  As a recording medium for supplying the program, for example, floppy (registered trademark) disk, hard disk, optical disk, magneto-optical disk, MO, CD-ROM, CD-R, CD-RW, magnetic tape, nonvolatile memory card ROM, DVD (DVD-ROM, DVD-R) and the like.

  As another program supply method, a client computer browser is used to connect to an Internet homepage, and the computer program itself of the present invention or a compressed file including an automatic installation function is downloaded from the homepage to a recording medium such as a hard disk. Can also be supplied.

  It can also be realized by dividing the program code constituting the program of the present invention into a plurality of files and downloading each file from a different homepage. That is, a WWW server that allows a plurality of users to download a program file for realizing the functional processing of the present invention on a computer is also included in the present invention.

  In addition, the program of the present invention is encrypted, stored on a recording medium such as a CD-ROM, distributed to users, and key information for decryption is downloaded from a homepage via the Internet to users who have cleared predetermined conditions. It is also possible to execute the encrypted program by using the key information and install the program on a computer.

  In addition to the functions of the above-described embodiments being realized by the computer executing the read program, the OS running on the computer based on the instructions of the program is used for the actual processing. The functions of the above-described embodiment can be realized by performing some or all of the processes.

  Furthermore, after the program read from the recording medium is written in a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, the function expansion board or The CPU or the like provided in the function expansion unit performs part or all of the actual processing, and the functions of the above-described embodiments are realized by the processing.

It is a figure which shows an example of the block configuration in the 1st Embodiment of this invention. It is a flowchart which shows the process sequence at the time of the normal recording in the 1st Embodiment of this invention. It is a flowchart which shows the transfer processing procedure from the live video display to the time shift reproduction video display in the 1st Embodiment of this invention. It is a flowchart which shows the process sequence at the time of performing processes, such as high-speed reproduction, at the time shift reproduction in the 1st Embodiment of this invention.

Explanation of symbols

100 monitor recording / reproducing apparatus body 101 network interface 102 CPU
DESCRIPTION OF SYMBOLS 103 Read-only memory 104 Memory in which high-speed random access is possible 105 Mass storage medium 106 Timer 107 Decoder for decoding video data 108 Display driver 110 Pre-alarm buffer 120 Image conversion processing unit 150 Camera unit 160 Display device

Claims (10)

Video receiving means for receiving video information from a camera unit, a randomly accessible mass storage medium, recording means for recording video information received from the video receiving means on the mass storage medium, and the mass storage medium Reproducing means for reading out the video information from the video and displaying the video on a display unit, time-shift reproducing means for simultaneously performing the recording means and the reproducing means in parallel, and an event trigger processing means for starting processing using an event as a trigger A recording / playback apparatus comprising: an event recording means for recording the event; a high-speed randomly accessible pre-event video storage medium that holds a video before the event occurs; and a timer;
The reproducing means adds time information obtained from the previous timer when storing the received video data in the large-capacity storage medium and the pre-event video storage medium, and uses either one of the time information. A recording / reproducing apparatus for selecting and reproducing a storage medium. The camera unit includes a network interface, an AD converter that digitizes captured video, and a moving image compression encoding unit that compresses and encodes the digitized video,
The recording / reproducing apparatus according to claim 1, wherein the video receiving unit is the network interface.   The camera unit is an imaging camera that transmits video information as an analog signal, an AD converter that digitizes the video information received by the video receiving means, and a moving image compression encoding that compresses and encodes the digitized video The recording / reproducing apparatus according to claim 1, further comprising: means.   4. The recording / reproducing apparatus according to claim 2, further comprising a frame decimation unit that decimates frames from video information that has been subjected to video compression encoding by the video compression encoding unit.   Simultaneously performing the process of recording the frame-thinned video, which has been frame-thinned by the frame-thinning means, on the large-capacity storage medium and the process of recording the video information before the frame-thinning on the pre-event video storage medium 5. The recording / reproducing apparatus according to claim 4, further comprising a processing unit.   The playback means stores the pre-event video storage when both the large-capacity storage medium and the pre-event video storage medium exist when playing back the video taken by the same camera unit and at the same time. 6. The recording / reproducing apparatus according to claim 5, wherein video recorded on the medium is preferentially reproduced.   7. The recording / reproducing apparatus according to claim 6, further comprising high-speed reproducing means for performing reproduction at least faster than the real-time reproduction speed.   The playback means is a fast-forward, skip, or when the video information being played back recorded on the large-capacity storage medium overlaps with video information recorded on the pre-event video storage medium by the high-speed playback means. 8. The recording / reproducing apparatus according to claim 6, wherein reading from the large-capacity storage medium is terminated and switching to reading from the pre-event video storage medium is performed. A first recording step of recording video information together with time information on a first storage medium;
A second recording step of recording the video information together with the time information on a second storage medium;
And a selective reproduction step of selecting and reproducing the first or second storage medium using real-time information and the time information.   A computer program that causes a computer to execute each step of the method according to claim 9.

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