JP2006287876A - Image recording and reproducing apparatus, image recording method, and image reproducing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image recording and reproducing apparatus, an image recording method, and an image reproducing method, wherein to a recorder out of a control of the image recording and reproducing apparatus also, when a record capacity of the recorder in an own apparatus is scarcely left, images of a monitor camera, etc. connected to the own apparatus can be recorded with respect to the other image recording and reproducing apparatus connected to a network. <P>SOLUTION: Since apparatus information on a record remaining capacity, etc. of each apparatus is exchanged between a plurality of image recording and reproducing apparatuses connected to the network, for instance, when the images of the monitor camera, etc. connected to the own image recording and reproducing apparatus, in the case where the remaining capacity of the recorder in the own image recording and reproducing apparatus is short, image data are transferred to the other image recording and reproducing apparatus for recording. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a video recording / reproducing apparatus, a video recording method, and a video reproducing method for performing distributed recording / reproduction management on a plurality of video recording / reproducing apparatuses connected to a network.

  With the spread of network technologies such as the Internet, there are an increasing number of monitoring systems that monitor images of surveillance cameras at remote locations via a network at a location away from the location where the surveillance camera is installed.

  In such a case, the video of the monitoring camera is recorded on a recording device or a recording medium such as a disk recorder to which the monitoring camera is connected.

  Also, when recording video, if the recording capacity of the recording device that is recording is running low, an alarm will be generated indicating that the remaining capacity is low, and a warning will be issued to the device administrator. It is necessary to take measures such as replacing recording equipment and increasing capacity. In this case, there is no problem if it can be dealt with immediately, but in order to do so, it is necessary to monitor by a resident at any time. Furthermore, manual replacement of recording devices may cause important alarm information to be missed, which is a problem for the monitoring system.

  For this reason, when the remaining capacity of the recording capacity decreases, it is desirable that the recording destination can be automatically changed to a recording device or recording medium having a sufficient recording capacity.

  As a method for continuing recording instead of other recording media when the remaining capacity of the recording capacity is insufficient, for example, a method described in Patent Document 1 is known.

  FIG. 9 is a diagram for explaining a conventional method disclosed in Patent Document 1. In FIG. As described above, when recording certain content data on the recording device, since a plurality of recording devices (HDR1, HDR2, HDR3) in the same recording device are connected via a digital interface such as IEEE1394, for example, When the recording capacity of HDR1 that started recording decreases, recording is performed following the next HDR2. Furthermore, when the remaining recording capacity of HDR2 is reduced, recording can be continued to the next HDR3, so that even when the recording capacity decreases, recording can be continued on another recording apparatus. It is.

JP 2004-199800 A

  However, in the conventional method as described above, if there are a plurality of recording devices in the same device and it is not known in advance that these recording devices exist, the recording capacity of such a recording device. It is not possible to perform control when the remaining battery power becomes low. That is, for example, content data cannot be transferred to another recording device and recorded on a recording device that is not managed by the recording device, such as a recording / reproducing device, because the recording device of the device itself is insufficient.

  The present invention has been made in view of such circumstances, and even when a recording device that is not managed by the video recording / reproducing device is connected to a network when the recording capacity of the recording device in the own device becomes small An object of the present invention is to provide a video recording / reproducing apparatus, a video recording method, and a video reproducing method capable of recording a video of a surveillance camera or the like connected to the other apparatus with respect to another video recording / reproducing apparatus that is installed. To do.

The above object can be achieved by the following constitution and method.
(1) A video recording / playback apparatus that records and plays back video captured by a monitoring camera in a monitoring system configured on a network using a plurality of video recording / playback apparatuses, each of the video recording / playback apparatuses including the video And recording the video or video from another video recording / playback device connected to the network to the self-recording device, and monitoring the remaining capacity of the self-recording device A video recording management unit that detects event information from the photographing unit, an NW management unit that manages transmission and reception via the network, and other video recordings on the network received at a predetermined timing A device information management unit that manages device information of the playback device, a GUI management unit that is a user interface, and a playback request from the GUI management unit. Whether the video requested to be played back by the device information management unit is recorded in the own video recording / playback device in accordance with a playback request from another video recording / playback device connected to the network. It is determined whether the video is recorded in another video recording / playback device, the video is read from the corresponding video recording / playback device, the video playback management unit for controlling playback, and the video read from the video playback management unit A video decoding unit for decoding.

(2) A video recording method in a video recording / playback method for recording and playing back video captured by an imaging means in a monitoring system configured on a network by a plurality of video recording / playback devices, and connected to the self-video recording / playback device When recording the video from the photographing means to the own recording device, the recording capacity of the recording device is checked, and the device information of the own video recording / reproducing device is connected to the network at a predetermined timing. To the other video recording / playback apparatus, and to store the device information of the other video recording / playback apparatus transmitted to the self-video recording / playback apparatus and to record the remaining recording capacity. When the required capacity is not reached, a recordable video recording / reproducing device is detected from the device information, and the video of the photographing means connected to the own video recording / reproducing device is detected. Recorded in serial detected video recording and reproducing apparatus, also records the video that is transferred to the host video recording and reproducing apparatus, the recording capacity shortage in another video recording and reproducing apparatus connected on the network.

(3) A video playback method in a video recording / playback method for recording and playing back video shot by a shooting unit in a monitoring system configured on a network, using a plurality of video recording / playback devices, and recording by the own video recording / playback device A predetermined area of the recording medium when playing back the video recorded by transferring the video of the photographing means connected to the own video recording / playback device to another video recording / playback device due to the lack of recording capacity of the medium When the device information of the transfer destination video recording / playback device is read from the transfer information recorded in the above and the requested video is on a recording medium in the other video recording / playback device, the corresponding information is sent via the network. By transmitting a request packet to output the corresponding video to the video recording / reproducing apparatus, the corresponding video is reproduced.

  In the video recording / reproducing apparatus described in (1) above, when the recording capacity of the video recording / reproducing apparatus becomes small, other video recording / reproducing apparatuses connected to the network having a sufficient recording capacity are connected to the own apparatus. It is possible to transfer and record the video of the connected photographing means, and when one video is distributed and recorded in a plurality of video recording / playback apparatuses, it is possible to continuously play back.

  In the video recording method described in (2) above, when the recording capacity of the video recording / reproducing apparatus is low, the video recording / reproducing apparatus is connected to another video recording / reproducing apparatus connected to a network having a sufficient recording capacity. It is possible to transfer and record the video of the photographing means.

  In the video playback method described in (3) above, when the recording capacity of the video recording / playback apparatus is low, the video recording / playback apparatus is connected to another video recording / playback apparatus connected to a network having a sufficient recording capacity. By transferring and recording the video of the photographing means, it is possible to continuously play back the video that has been distributed and recorded on a plurality of video recording and playback devices.

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

  FIG. 1 is a system configuration diagram showing a system configuration of a video recording / reproducing apparatus according to an embodiment of the present invention. In this figure, this system comprises a plurality of input devices 101a to 101c and video recording / reproducing devices 102a to 102c. The video recording / reproducing devices 102a to 102c are connected via a network (NW) 100. ing. The video recording / playback apparatus 102a (102b, 102c) includes an external terminal management unit, a video encoding unit, a video recording management unit, an event detection unit, an NW management unit, a device information management unit, a GUI management unit, a video playback management unit, a video It has a decryption unit. For example, an event such as motion detection is output from the input device 101a such as a surveillance camera, and is input to the video recording / reproducing device 102a. In accordance with this event, recording is started in the video recording / reproducing apparatus 102a. However, if there is no room in the remaining recordable capacity of the recording device (not shown here) in the video recording / reproducing device 102a, the other video recording / reproducing device 102b or 102c connected to the network 100 is not used. On the other hand, the video from the input device 101a such as a monitoring camera connected to the self-video recording / reproducing device is transferred and recorded. At the same time, an alarm indicating that the recording capacity is insufficient is issued to the administrator who manages the video recording / reproducing apparatus 102a.

  Next, a video recording / playback method of the video recording / playback apparatus 102a (102b, 102c) constituting this system will be described in detail.

  FIG. 2 is a flowchart for explaining the video recording method of the present embodiment. First, in the event detection determination step (S201), it is checked whether an event is input. An event here is a motion detection event detected by image processing or the like that is determined to detect motion in video from a surveillance camera, or a video loss event when a connection cable of a surveillance camera or the like is disconnected And events from external terminals. However, it is not limited to these events. If such an event has been input, in the next recording capacity determination step (S202), it is determined whether the recording capacity in the own apparatus is sufficient or not in the memory holding the recording capacity in the own apparatus. Information is read and determined. A method for recording information relating to the recording capacity will be described later. If the recording capacity is sufficient for recording, in the video recording step (S203), recording of the video from the target monitoring camera or the like is started to the recording device in the own device.

  If it is determined that the remaining recording capacity is insufficient for recording, an alarm indicating that a capacity shortage has occurred is issued in the next capacity shortage alarm issuing step (S205). The administrator is urged to take measures to increase the recording capacity by physically increasing the recording capacity or saving the recorded data.

  Subsequently, in the capacity check step (S206) of the other video recording / playback apparatus, the stored recording capacity information of the other video recording / playback apparatus is checked, and in the next transfer possibility determination step (S207), the recording capacity is set. It is determined whether there is a video recording / reproducing apparatus having a margin.

  If it is determined in the transfer enable determination step (S207) that there is a video recording / playback apparatus having a sufficient recording capacity, the transfer destination information is held in the memory of the apparatus itself as a transfer recording table. The format of this transfer record table will be described later. If it is determined in the video transfer processing step (S208) that transfer is possible, the video of the monitoring camera or the like in which the event has occurred is transmitted to the selected video recording / playback apparatus using a UDP (User Datagram Protocol) packet. . However, this video transmission may be TCP (Transmission Control Protocol) communication or any method.

  Thereafter, in a predetermined time elapse determination step (S204), video recording is stopped after a predetermined time. At this time, in the recording capacity determination step (S202), it is determined that the remaining capacity of the recording capacity in the own device is insufficient, and other video recording / reproducing devices such as a monitoring camera connected to the own video recording / reproducing device When the video is being transferred, the transfer process is stopped and a CGI (Common Gateway Interface) command is transmitted to the transfer destination video recording / reproducing apparatus so as to stop the recording. However, although the CGI method has been described here as the command transmission method, the command may be transmitted by TCP communication or UDP communication, and any method may be used.

  Further, when it is determined in the capacity check step (S206) of the other video recording / playback apparatus that an event in which the remaining capacity of all the video recording / playback apparatuses connected to the network has occurred cannot be recorded. Determines that there is no transferable video recording / playback apparatus in the transfer enable determination step (S207).

  Next, whether the device administrator outputs an urgent alarm for an emergency situation where there is no transferable video recording / playback device connected to the network in advance, or is it overwritten at the head of the recording device? If, for example, an emergency alarm is set to be output, emergency processing is selected in the emergency processing determination step (S209), and in the next emergency alarm reporting step (S210) Emergency alarms continue to be issued until the administrator clears them. When the administrator saves the recorded contents of the recording device to another recording device and cancels the emergency alarm, recording starts from the head of the recording device.

  Also, if the device administrator has set in advance such an emergency situation to overwrite from the beginning of the recording device, the recording address of the recording device is set in the loop processing step (S211). Returning to the top, video is recorded in the next video recording step (S203).

  In the emergency mode described above, the administrator who manages the video recording / playback apparatus designates the emergency mode in advance. In the alarm mode, an emergency alarm is issued. It is overwritten from the beginning. This emergency mode is when the remaining capacity of all video recording / playback apparatuses on the network is small. When there is no recordable remaining capacity of the self-video recording apparatus, all video recording / playback apparatuses have a sufficient recording capacity. As long as you don't miss the video of the event. Also, if there is no recordable remaining capacity of the video recording device and there is not enough recording capacity in all video recording and playback devices, enter emergency mode and leave past events or new events You can choose to prioritize whether to record.

Here, a method for checking whether the recording capacity is excessive or insufficient for recording will be described. Assuming that the capacity of the recording capacity described above is X [bytes], the preset recording rate is Y [bytes / second], and the recording time after the occurrence of an event is Z [seconds], the required recording capacity A [Byte] can be calculated by the following equation (1).
A = Y × Z [bytes] (1)

  Therefore, the calculated A value is compared with the X value of the remaining capacity, and it is determined whether or not recording is possible in the recording apparatus in the apparatus itself.

  Next, storage of transfer information in the case where the recording device's remaining capacity is insufficient and the video of the monitoring camera or the like of the own device is transferred to and recorded on another video recording / reproducing device. The format will be described with reference to FIG. The video recording management unit in the video recording / reproducing apparatus has a transfer recording table to another video recording / reproducing apparatus as shown in FIG. This table stores information such as the IP address of the transfer destination, the event occurrence time, the channel number of the monitoring camera, and the type of event that has occurred. Here, VMD is an abbreviation for Video Motion Detection, which indicates a motion detection event, LOSS indicates a video loss event, and COM indicates an external terminal event.

  Next, a processing procedure when the video recording / playback apparatus receives other video recording / playback apparatus information will be described with reference to FIG. First, in another device information reception determination step (S401), it is checked whether or not recording device information of another device is received from another video recording / reproducing device. If not received, the determination is repeated again in the other device information reception determination step. If other device information has been received, in the next other device information storing step (S402), information relating to the recording device of the other video recording / reproducing device is extracted from the received packet, and the extracted device information is stored in the memory. Store. At this time, if the device information of the other video recording / reproducing device is already stored, the device information of the corresponding device is updated.

  The remaining capacity of the recording device in the video recording / reproducing apparatus connected to the network is managed by the remaining capacity recording management table shown in FIG. The remaining capacity recording management table stores the IP address, remaining capacity, and update time of each video recording / reproducing apparatus. The device information of each video recording / reproducing device is transmitted at a preset time by, for example, a method of transmitting to all video recording / reproducing devices having the same subnet number IP address.

  Next, the device information transmission method will be described with reference to FIG. In the recording capacity check time determination step (S601), the apparatus information management unit of the video recording / reproducing apparatus determines whether it is the recording capacity check time. This recording capacity check is performed as needed at a predetermined timing. For example, the scheduling is performed every minute. If it is time to check the recording capacity, the recording capacity is checked in the next recording capacity check step (S602). This check process is to check how much B (bytes) of free space is left in the recording apparatus.

  In accordance with the format shown in FIG. 5 described above, the information on the checked result is updated in the recording content storing step (S603) as the recording device information of the own device. At the same time, in the own device information transmission step (S604), the recording device information of the own device is also transmitted to other video recording / reproducing devices. In this transmission processing, for example, transmission is performed to all video recording / reproducing apparatuses having the same subnet number IP address.

  In this way, it is possible to record a video from a surveillance camera or the like connected to the self-video recording / reproducing apparatus that cannot be recorded in the self-video recording / reproducing apparatus on another video recording / reproducing apparatus.

  In the above description, the case where recording cannot be performed on the recording device in the self-video recording / playback device has been described. However, recording is performed when video is transferred due to insufficient recording capacity in another video recording / playback device connected to the network. The flow is similar. That is, a transfer recording event input from the network is detected in the event detection step (S201), and the same processing is performed thereafter.

  Next, a method for reproducing the recorded contents distributed and recorded as described above by the video reproduction management unit of the video recording / reproducing apparatus will be described with reference to FIG. First, in a reproduction instruction check step (S701), it is checked whether or not a reproduction instruction is input. If the reproduction instruction is not input, the process returns to the reproduction instruction check step (S701) again, and the check is repeated. If a reproduction instruction has been input, next, based on the input time, channel information, and event type information, in the recording destination check step (S702), transfer recording to the other video recording / reproducing apparatus described above is performed. With reference to the table, it is checked whether or not the video of the surveillance camera or the like connected to the own device is transferred to and recorded on another video recording / reproducing device. If the video has not been transferred to another video recording / reproducing apparatus, the corresponding video is read from the recording apparatus in the own apparatus and outputted in a reproduction video output step (S705). In addition, if the channel number, event type, and event occurrence time requested for playback exist in the transfer recording table to the other video recording / playback device described above, the video is transferred to the other video recording / playback device. Therefore, in the reproduction video output request transmission step (S703), a reproduction request is transmitted using the CGI command so as to output the corresponding video to the video recording / reproducing apparatus having the corresponding IP address of the transfer destination. To do. However, although the command transmission method is CGI here, the command may be transmitted by TCP communication or UDP communication, and any method may be used. Then, in a playback video reception step (S704) from another device, the corresponding video is received and a playback video output step (S705) is executed.

  With the video playback method as described above, it is possible to play back video from a surveillance camera or the like connected to the self-video recording / playback apparatus that could not be recorded in the self-video recording / playback apparatus.

  Next, the configuration of the above-described video recording / reproducing apparatus 102a (102b, 102c) will be described in detail with reference to FIG. The video recording / playback apparatus 102a (102b, 102c) includes an external terminal management unit 801, a video encoding unit 802, a video recording management unit 803, an event detection unit 804, an NW management unit 805, and a device information management unit 806. A GUI management unit 807, a video reproduction management unit 808, a video decoding unit 809, and a recording device 810.

  First, a description will be given according to a recording flow. An event occurs from a camera or an external terminal, and the external terminal management unit 801 detects the event. Next, the type of the event detected by the event detection unit 804 is determined. The types such as the VMD event, the LOSS event, and the COM event described above are determined. Next, the video recording management unit 803 checks the remaining capacity of the recording device 810. Whether or not recording is possible is determined by the above-described equation (1). If recording is possible, the video of the corresponding channel in which the event is detected is captured by the external terminal management unit 801. The captured video is encoded by the video encoding unit 802, and the encoded video is output to the video recording management unit 803 and recorded in the recording device 810. Also, the recording time is set in advance, and after the set time has elapsed, the capturing of the video of the monitoring camera or the like of the corresponding channel number where the event has occurred from the external terminal management unit 801 is stopped. If the video recording management unit 803 checks the remaining capacity of the recording device 810 and determines that recording is not possible according to equation (1), the video recording management unit 803 outputs a result indicating that recording is not possible to the event detection unit 804 to obtain device information. The management unit 806 is inquired as to whether or not another video recording / playback apparatus is available. If there is a vacant video recording / reproducing apparatus in the apparatus information management unit 806, the fact that the information has been transferred to the apparatus information of the video recording / reproducing apparatus is recorded in accordance with the format of FIG. The IP address is output to the NW management unit 805. The NW management unit 805 packetizes the video data encoded by the video encoding unit 802 and transmits the packet data from the NW management unit 805 to the video recording / playback apparatus having the corresponding IP address.

  Next, a description will be given according to the playback flow. First, the GUI management unit 807 receives a reproduction request from a GUI (Graphical User Interface) that is a user interface. Next, the video playback management unit 808 extracts playback information such as the event type, event occurrence time, and channel number from the playback request information, and determines whether the video data is recorded in the self-recording device. Contact As a result of the inquiry, if the video data is recorded in the self-recording apparatus, the corresponding video data is read from the recording apparatus 810 in the self-recording apparatus, output to the video decoding unit 809 and decoded, and the GUI management unit 807. The playback video is displayed on the user screen. If the inquiry results in video data that is not recorded in the recording device, the video playback management unit 808 receives the IP address information of the transfer destination from the device information management unit 806, and determines the event type and event occurrence. Playback information such as time and channel number is packetized, and a video output request is transmitted from the NW management unit 805 to the video recording / playback apparatus having the IP address of the corresponding transfer destination. After that, when the NW management unit 805 receives the video as a result of issuing the transmission request, it is output to the video reproduction management unit 808, and the encoded video data is extracted from the received packet, and is output to the video decoding unit 809 for decoding. To do. Next, the decoded video data is output to the GUI management unit 807, and the playback video is displayed on the user screen.

  Next, a description will be given according to a flow for managing recording information in the video recording / reproducing apparatus. The recorded information is checked by the video recording management unit 803 every certain period. The checked result is output to the device information management unit 806, and the output record information is stored in the memory according to the format of FIG. Next, in order to send the recording information output to the device information management unit 806 to another video recording / playback device, the recording information is packetized and output to the NW management unit 805, for example, a network having the IP address of the same subnet Transmission is performed from the NW management unit 805 to all the above video recording / playback apparatuses.

  In addition, after receiving the recording information from another video recording / reproducing apparatus by the NW management unit 805, the apparatus information is extracted from the received packet, and the extracted apparatus information is output to the apparatus information management unit 806, as shown in FIG. Store in memory according to format.

  With the above device configuration, when the video recording / playback device cannot record due to insufficient remaining capacity, the video from the surveillance camera etc. connected to the video recording / playback device is transferred to other video recording / playback devices on the network. At the same time as recording, it issues a recording capacity shortage alarm, informs the device administrator that the recording capacity is insufficient, and transfers and records the video to other video recording / playback devices on the network. Important event information will not be missed, and video from the surveillance camera connected to the self-video recording / playback device that could not be recorded on the recording device within the self-video recording / playback device will be recorded and played back at the transfer destination. A video recording / reproducing apparatus that can be read out from the apparatus and reproduced can be realized.

  The present invention provides a video from a surveillance camera or the like that is connected to the video recording / reproducing apparatus connected to the other video recording / reproducing apparatus connected to a network having a sufficient recording capacity when the recording capacity of the video recording / reproducing apparatus is low. Can be transferred and recorded, and when one video is distributed and recorded in a plurality of video recording / playback apparatuses, it is possible to continuously play back, and a surveillance camera system, etc. Useful for.

The system block diagram which shows the system configuration | structure of the video recording / reproducing apparatus concerning embodiment of this invention Flowchart for explaining a video recording method in an embodiment of the present invention The figure which shows the transfer recording table to the other video recording / reproducing apparatus in embodiment of this invention. The flowchart for demonstrating the process sequence when the apparatus information from the other video recording / reproducing apparatus in embodiment of this invention is received. The figure which shows the remaining capacity recording management table which manages the remaining capacity of the recording device in embodiment of this invention The flowchart for demonstrating the operation | movement which transmits the apparatus information of the self-video recording / reproducing apparatus in embodiment of this invention with respect to another video recording / reproducing apparatus. Flowchart for explaining a video reproduction method in an embodiment of the present invention The block diagram which shows the structure of the video recording / reproducing apparatus in embodiment of this invention Diagram for explaining a conventional example

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Network 101a, 101b, 101c Input device 102a, 102b, 102c Video recording / reproducing apparatus 801 External terminal management part 802 Video encoding part 803 Video recording management part 804 Event detection part 805 NW management part 806 Device information management part 807 GUI management part 808 Video reproduction management unit 809 Video decoding unit 810 Recording device

Claims (3)

A video recording / playback device that records and plays back video captured by a monitoring camera in a monitoring system configured on a network, with a plurality of video recording / playback devices,
Each of the video recording / playback devices
Photographing means for photographing the video;
A video recording management unit that performs control to record the video or video from another video recording / playback device connected to the network on the self-recording device, and monitors a remaining capacity of the recording capacity of the self-recording device;
An event detector for detecting event information from the photographing means;
An NW management unit that manages transmission and reception via the network;
A device information management unit for managing device information of other video recording / playback devices on the network received at a predetermined timing;
A GUI management unit which is a user interface;
In response to a playback request from the GUI management unit or a playback request from another video recording / playback device connected to the network, the video requested to be played back by the device information management unit is stored in the own video recording / playback device. A video playback management unit that determines whether the video is recorded or recorded on another video recording / playback device on the network, reads video from the video recording / playback device, and controls playback;
A video decoding unit for decoding the video read from the video reproduction management unit;
A video recording / reproducing apparatus comprising: A video recording method in a video recording / playback method for recording and playing back video shot by a shooting means in a monitoring system configured on a network with a plurality of video recording / playback devices,
When recording the video from the photographing means connected to the self-video recording / reproducing device to the self-recording device, the recording capacity of the self-recording device is checked and the device of the self-video recording / reproducing device is at a predetermined timing. The information is transmitted to another video recording / reproducing apparatus connected to the network, and the device information of the other video recording / reproducing apparatus transmitted to the own video recording / reproducing apparatus is stored, and the rest When the recording capacity is less than the capacity required for recording, the recordable video recording / reproducing device is detected from the device information, and the video of the photographing means connected to the own video recording / reproducing device is detected. The recorded video is recorded by the video recording / playback device, and is transferred to the video recording / playback device due to a lack of recording capacity in another video recording / playback device connected to the network. Video recording method for recording. A video playback method in a video recording / playback method for recording and playing back video shot by a shooting means in a monitoring system configured on a network with a plurality of video recording / playback devices,
When playing back the video recorded by transferring the video of the photographing means connected to the self-video recording / playback device to another video recording / playback device due to the lack of recording capacity of the recording medium of the self-video recording / playback device When the device information of the transfer destination video recording / reproducing device is read from the transfer information recorded in the predetermined area of the recording medium, and the requested video is in the recording medium in the other video recording / reproducing device, A video playback method for playing back a corresponding video by transmitting a request packet to output the corresponding video to the corresponding video recording / playback apparatus via the network.

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