JP2005353193A - Digital video recording and reproducing apparatus and its recording and reproducing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize a digital storage reproducing apparatus which can perform reproduction during recording without interrupting recording or reproducing, in reproduction processing during video information is recorded. <P>SOLUTION: This digital video recording and reproducing apparatus 6 is provided with a storage part 5 constituted of two recording media 51, 52, while video information is written in the one storage medium 51 by a recording and reproducing control part 3, video information previously recorded is read out from the other recording medium 52, its operation is performed alternately for the recording media 51, 52. Thereby, the video information is recorded and reproduced without interruption. Also, the apparatus functions as a mirror buffer by combining buffers 510, 520 and the storage media 51, 52, live-wire insertion and pulling of the recording medium 51 or 52 can be performed, recording and reproducing of video information can be performed even during the recording medium is replaced. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a digital video recording / reproducing apparatus of a camera monitoring system and a recording / reproducing method thereof.

  In many camera monitoring systems, a monitoring target monitors a monitoring target at a monitoring center or the like while recording a video of the monitoring target on a video recording device. This video monitoring screen may be monitored with a real-time image taken in the normal video signal band, but the monitoring screen is monitored with a time-lapse image for long-term recording, and the screen is stored once in the video recording device. There are cases where a method of immediately reading out and displaying the recorded video information is displayed.

This method is often employed for remote monitoring video information and a plurality of video information monitoring simultaneously monitoring many targets. In the monitoring method of monitoring while confirming the recording of the monitoring video information, playback during recording is performed while buffering the recorded video signal and the playback display video signal. For this reason, there is a problem that the recording / playback buffer overflows when the recording video signal encoding speed and the playback display video signal speed are different. In addition, there is a problem that the recording / playback buffer becomes empty and the video is interrupted. Therefore, in order to prevent problems such as overflow, a method of predicting and controlling the operation of the buffer while monitoring the load state is employed in order to accurately perform playback during recording (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 2003-22604 (page 12, FIG. 9)

  In the camera monitoring system, video signals to be recorded and played back are recorded and played back during recording, and video information is recorded and played back on the recording medium. However, in order to prevent problems such as buffer overflow, the buffer load status is reduced. Complicated buffer processing such as monitoring and predictive control is required, and there are problems that are difficult to predict depending on the monitoring situation.

  The present invention has been made to solve the above-described problem, and provides a digital storage / reproduction apparatus for a camera monitoring system and a recording / reproduction method therefor, in which recording is not interrupted or is not interrupted in a reproduction process during recording of video information. The purpose is to do.

  In order to achieve the above object, a digital video recording / reproducing apparatus according to the present invention comprises first and second storage media, encoding means for digitally encoding TV video information to generate an encoded video signal, and the code The encoded video signal from the converting means is divided into data block units of a predetermined size, and in the first period, the first data block is written into the first storage medium and at the same time from the second storage medium. Repeatedly reading the first data block from the first storage medium simultaneously with writing the second data block to the second storage medium in the second period. Recording and playback control means for simultaneously recording and playing back the TV video information, and the first and second data read from the recording and playback control means Receiving a lock, characterized by comprising a decoding means for restoring the television video information.

  According to the recording / reproducing method of the digital video recording / reproducing apparatus of the present invention, the encoded video signal is generated by digitally encoding the television video information, and the encoded video signal is divided into data block units of a predetermined size. In the cycle, the first data block is written to the first storage medium, and at the same time, the data block before the first data block is read from the second storage medium. In the second cycle, the first data block is read into the second storage medium. At the same time as writing the second data block, the first data block is read from the first storage medium, and the television image information is recorded and reproduced at the same time by repeating the first and second cycles. The output first and second data blocks are restored to the television video information.

  According to the present invention, two sets of storage media for recording video information are used, and the operation of reading the previously recorded video information from the other storage medium while recording the video information on one storage medium is alternated. By repeating the above, video information can be reproduced during recording without interruption.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a block diagram showing a functional configuration of a digital video recording / reproducing apparatus according to an embodiment of the present invention.

  In FIG. 1, a digital video recording / reproducing apparatus 6 includes a recording processing unit 1, a reproduction processing unit 2, a recording / reproducing control unit 3, an operation unit 4, and a storage unit 5.

  The recording processing unit 1 converts a plurality of encoding units 11 that convert video information transmitted from a plurality of surveillance cameras into encoded video signals, and converts the plurality of encoded video signals into multiplexed data for recording and reproduction. It is comprised from the multiplexing part 12 transmitted to the control part 3. FIG. In addition, you may comprise this encoding part 11 and the multiplexing part 12 by one.

  When receiving the multiplexed video data, the recording / playback control unit 3 generates a video data block of a predetermined size and records it in the storage unit 5, and records the video data block recorded from the storage unit 5. Perform playback control to read.

  That is, the recording / playback control unit 3 edits the received encoded video signal into a block unit of a predetermined data size (hereinafter, video data in this block unit is referred to as a video data block) in order to write the received encoded video signal into the storage unit 5. To do. Therefore, the reading and writing cycle of the storage unit 5 corresponds to the time for reading and writing the video data block.

  The data size of the video data block is determined by the encoding method, the code acceleration, and the number of frame screens. For example, a block unit for each frame image such as MJPEG (motion Jpeg) or a stream image obtained by combining a plurality of the one frame images is used as a block unit. It is initialized by a predetermined method.

  The operation unit 4 selects video information to be recorded or reproduced by the digital video recording / reproducing apparatus 6, sets an encoding speed, and sets a unit of a video data block. In addition, the input device includes a button, a switch, and the like for setting conditions such as a display form of a display device such as simultaneously displaying video information from a plurality of monitoring cameras on one screen.

  The storage unit 5 includes two storage media 51 and 52. For these storage media 51 and 52, for example, a hard disk device capable of recording for a long time is used. The recording / playback control unit 3 performs writing to the storage media 51 and 52 and reading from the storage media 51 and 52 via the buffers 510 and 520. Then, the recording / reproducing control unit 3 transmits, for example, data of a new video data block and a write command to the storage medium 51 at a predetermined cycle, and the other storage is performed during the timing when the writing to the storage medium 51 is performed. A command for reading the recorded video data block is transmitted to the medium 52 to perform reading.

  The writing process and the reading process for the storage media 51 and 52 are alternately switched by the recording / reproducing control unit 3. Accordingly, since the digital video recording / reproducing apparatus 6 always writes the video data block to one storage medium and reproduces the video data block from the other storage medium, the video information for recording and reproduction is prevented from being interrupted.

  The reproduction processing unit 2 includes a separate decoding unit 21 and a plurality of display device interface units 22. The demultiplexing / decoding unit 21 demultiplexes the multiplexed encoded video signal of the video data block alternately read from the two storage media 51 and 52, and then displays the separated encoded video signal. Restore to video information. Then, the display image information restored via the selected interface unit 22 is transmitted to the display device.

  The interface unit 22 converts video information into, for example, an NTSC format video signal, and transmits the video signal to a display device connected to the digital video recording / reproducing device 6. Therefore, on the display device, the video information recorded in the storage unit 5 is reproduced and displayed in real time.

FIG. 2 is a flowchart showing an operation procedure of the digital video recording / reproducing apparatus.
The operation of the digital video recording / playback apparatus will be described below with reference to FIG.
The digital video recording / reproducing apparatus 6 of the present embodiment performs a time lapse process for recording surveillance camera video for a long time.

  The digital video recording / reproducing apparatus 6 first receives initial setting information from the operation unit 4, encodes (in this case, MJPEG), data block unit (here, 1 frame is 100 kbytes), A cycle T (in this case, 1 second) for writing and reading is set and notified to the recording processing unit 1, the playback processing unit 2, and the recording / playback control unit 3 (step s1).

  Video information from a plurality of surveillance cameras is received by a corresponding encoding unit 11 of the recording processing unit 1 to perform long-time recording, and a low-speed encoded MJPEG code of time lapse processing by the encoding unit 11 Converted into a video signal (hereinafter referred to as MJPEG signal) (step s2). Here, it is assumed that the MJPEG signal is composed of, for example, 20 kbytes / 1 frame / second.

  The plurality of MJPEG signals output from each encoding unit 11 are further transmitted to the multiplexing unit 12 and multiplexed (step s3). The multiplexed MJPEG signal is transmitted from the recording processing unit 1 to the recording / reproducing control unit 3. The recording / playback control unit 3 generates the multiplexed MJPEG signal in units of video data blocks and writes it in the storage unit 5 (step s4).

  FIG. 3 is a diagram illustrating a timing relationship in which the recording / playback control unit 3 writes the video data block to the storage unit 5 and reads the video data block from the storage unit 5.

  FIG. 3A shows write / read cycles for the storage media 51 and 52 of the storage unit 1, and each cycle T1 to Tn is 1 second. The recording / playback control unit 3 writes the odd-numbered video data block to the storage medium 51 and simultaneously writes the even-numbered video data block to the storage medium 52 and the phase pA for reading the even-numbered video data block from the storage medium 52. At the same time, the phase pB for reading out odd-numbered video data blocks from the storage medium 51 is alternately executed. For this reason, the recording / playback control unit 3 writes data to the storage medium 51 and the buffer 510, the recording medium 52 and the buffer 520, and alternately transmits read commands.

  FIG. 3B is a diagram showing a video data block written to the storage medium 51 or 52. The video data blocks transmitted in time series from the recording / reproduction control unit 3 are alternately written into the storage medium 51 or 52 in accordance with each command from the recording / reproduction control unit 3. The video data blocks alternately read from the storage medium 51 or 52 are transmitted to the reproduction processing unit 2 via the recording / reproduction control unit 3.

  That is, the odd-numbered video data block transferred from the recording / playback control unit 3 is temporarily stored in the buffer 510, and the odd-numbered video data block (# 1) is stored in the storage medium 51 by the FIFO operation of the buffer 510 in the period T1. Simultaneously with the writing, the even-numbered video data block (# 0) read from the storage medium 52 is output to the recording / playback processing unit 3. It is assumed that the video data block (# 0) has been written to the recording medium 52 in the immediately preceding phase.

  The even-numbered video data block transferred from the recording / playback control unit 3 is temporarily stored in the buffer 520. In the next cycle T2, the even-numbered video data block (# 2) is stored in the recording medium 52 by the FIFO operation of the buffer 520. Simultaneously with the writing, the odd-numbered video data block (# 1) read from the storage medium 51 is output to the recording / playback processing unit 3. Similarly, in the cycle T3, the odd-numbered video data block (# 3) is written to the storage medium 51 by the FIFO operation of the buffer 510, and at the same time, the even-numbered video data block (#) read from the storage medium 52 2) is output to the recording / reproducing processor 3 (steps s5 and s6). Thereafter, similar processing is repeatedly executed.

  The recording / playback control unit 3 transmits the received video data block to the separation / decoding unit 21 of the playback processing unit 2. The demultiplexing / decoding unit 21 demultiplexes and decodes the received multiplexed video data block, and transmits it to the set ones of the plurality of interface units 22 (step s7).

  The plurality of interface units 22 edit the restored video information in accordance with the set display conditions (for example, superimpose and display on one screen) and transmit it to the corresponding display device (step s8). This display condition is input and set from the operation unit 4 during initial setting or monitoring.

  The video data block received by the separation / decoding unit 21 is a continuous video data block delayed by one frame from the write timing. Since the video data block is a one-frame screen, the received video data block is separated. If decoded, the video information can be reproduced and displayed during recording without interruption.

  In the above-described embodiment, the video data blocks in which video signals from a plurality of cameras are multiplexed are alternately stored in the storage media 51 and 52. As a result, the storage media 51 has an odd-numbered video data block, The storage medium 52 stores even-numbered video data blocks. However, in the digital video recording / reproducing apparatus 6, there are cases in which both odd-numbered and even-numbered video data blocks are desired to be stored in both the storage media 51 and 52 in consideration of redundancy at the time of replacement of the storage media.

  In that case, the video data block is stored in the storage media 51 and 52 at a writing speed twice that of the above embodiment. At this time, the video data block is temporarily stored in the recording / playback control unit 3 for one cycle so that the video data is not lost by writing at twice the speed, and then stored in the storage medium 51 via the buffers 510 and 520. The method of writing to 52 is assumed.

  FIG. 4 shows the timing when video data blocks are alternately stored in the storage media 51 and 52. The storage media 51 and 52 perform the write operation and the read operation at twice the speed (that is, T / 2 period). It is executed alternately.

  For example, the video data block (# 1) transferred from the recording / playback control unit 3 is temporarily stored in the buffer 510 and written to the storage medium 51 at the timing of the phase pA of the T / 2 cycle. The data block (# 0) is read and output to the recording / playback control unit 3. The video data block (# 1) transferred from the recording / playback control unit 3 is also temporarily stored in the buffer 520 and written to the storage medium 52 at the timing of the subsequent phase pB of the T / 2 cycle. The video data block (# 1) written in the phase pA is read and output to the recording / playback control unit 3. During this period, the next video data block (# 2) is temporarily stored in the recording / playback control unit 3. Note that the video data block (# 0) is written in the storage medium 52 in the immediately preceding phase pB.

  Similarly, the video data block (# 1) is read from the storage medium 52 at the same time as the video data block (# 2) is written to the storage medium 51 at the timing of the phase pA of the next T / 2 cycle. And output to the recording / reproducing control unit 3. At the same time as the video data block (# 2) is written to the storage medium 52 at the timing of the subsequent phase pB of the T / 2 cycle, the video data block (# 2) written in the phase pA is read from the storage medium 51 at the same time. And output to the recording / reproducing control unit 3. During this period, the next video data block (# 3) is temporarily stored in the recording / playback control unit 3. Thereafter, similar processing is repeatedly executed.

  As a result, both odd-numbered and even-numbered video data blocks are stored in the two storage media 51 and 52 (data backup is realized). Accordingly, it is possible to realize a digital video recording / reproducing apparatus having redundancy in which the video data block is not lost even if one of the storage media is replaced.

  Note that the storage capacity of each of the buffers 510 and 520 may be increased to store several minutes of video information as mirror buffers of the storage media 51 and 52.

FIG. 5 is another block diagram showing a connection configuration between the storage unit 5 and the recording / reproducing control unit 3.
In FIG. 5, the recording processing unit 1, the reproduction processing unit 2, the recording / reproduction control unit 3, and the storage unit 5 are connected by a bus line 7. The video data block of the encoded video signal is transferred to each device via the bus line 7, and further written to the storage media 51 and 52 or read from the storage media 51 and 52 via the buffers 510 and 520, respectively. Is done.

  In this embodiment, since HDDs are used as the storage media 51 and 52, these HDDs are mounted with a hot-swap function with the digital video recording / reproducing apparatus 6 via the bus interface 530. The buffers 510 and 520 may be mounted using a mirror buffer function and a hot-swap function.

  With such a configuration, for example, even when the storage medium 51 is removed from the digital video recording / reproducing apparatus 6 for a few minutes due to replacement of the HDD or the like, the buffer 510 is connected to the HDD of the storage medium 51. The video data block is written into and read out from the buffer 510. In this case, when the replacement storage medium (HDD) 51 is loaded, the video data block temporarily stored in the buffer 510 is written into the replacement storage medium 51. Therefore, if the HDD replacement process is completed before the buffer 510 overflows, the video information will not be interrupted.

  Therefore, according to the embodiment of the present invention, it is possible to realize reproduction during recording with redundancy even if the storage medium is replaced. In addition to the HDD, the recording medium may be a removable storage medium such as a DVD.

  In the above description, the time lapse process with a low encoding speed is taken as an example. However, an encoded video signal with a higher or lower encoding speed that can be written to or read from a recording medium is used as a video data block. Thus, the present invention can be applied to a digital video recording / reproducing apparatus that reproduces video information during recording.

1 is a block diagram showing a functional configuration of a digital video recording / reproducing apparatus according to an embodiment of the present invention. 3 is a flowchart showing an operation procedure of the digital video recording / reproducing apparatus according to the embodiment of the present invention. The figure which shows the timing relationship of the writing of the video data block of the digital video recording / reproducing apparatus concerning embodiment of this invention, and reading. The figure which shows the other timing relationship of writing of the video data block of the digital video recording / reproducing apparatus concerning embodiment of this invention, and reading. The block diagram which shows other embodiment which shows the connection relationship between the memory | storage part and recording / reproducing control part of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Recording processing part 11 Encoding part 12 Multiplexing part 2 Reproduction | regeneration processing part 21 Separation / decoding part 22 Interface part 3 Recording / reproducing control part 4 Operation part 5 Storage part 51,52 Storage medium 510,520 Buffer 6 Digital video recording / reproducing apparatus 7 Bus line

Claims (8)

First and second storage media;
Encoding means for digitally encoding television video information to generate an encoded video signal;
The encoded video signal from the encoding means is divided into data block units of a predetermined size, and in the first period, the first data block is written to the first storage medium and at the same time from the second storage medium. A data block before the first data block is read, and in the second period, the second data block is written to the second storage medium, and at the same time, the first data block is read from the first storage medium. Recording / playback control means for simultaneously recording and playing back the TV video information by repeating;
A digital video recording / reproducing apparatus comprising: decoding means for receiving the first and second data blocks read from the recording / reproducing control means and restoring the data to the television video information.   2. The digital video recording / reproducing apparatus according to claim 1, wherein the television video information is surveillance camera video information, and is digitally encoded by a time lapse process by the encoding means.   2. The digital video recording / reproducing apparatus according to claim 1, wherein the sizes of the first and second data blocks are configured in block units of one frame screen or in units of integer multiples of one frame screen.   The digital video recording / reproducing apparatus according to claim 1, wherein the first and second storage media are media that can be hot-plugged. The encoding means digitally encodes a plurality of TV video information, further multiplexes the plurality of encoded video signals, and outputs to the recording / playback control means,
2. The decoding unit according to claim 1, wherein the decoding unit separates and decodes the multiplexed first or second data block read from the first or second storage medium. Digital video recording / playback device. First and second storage media that can be hot-plugged;
First and second buffers provided corresponding to the first and second storage media;
Encoding means for digitally encoding television video information to generate an encoded video signal;
The encoded video signal from the encoding means is divided into data block units of a predetermined size, and in the first period, the first data block is written to the first storage medium via the first buffer at the same time. A data block before the first data block is read from the second storage medium through the second buffer, and the second data block is read from the second storage medium in the second cycle in the second period. Recording / reproduction control means for simultaneously recording and reproducing the television video information by repeating reading the first data block from the first storage medium through the first buffer simultaneously with writing through the buffer When,
A digital video recording / reproducing apparatus comprising: decoding means for receiving the first and second data blocks read from the recording / reproducing control means and restoring them to the television video information.   7. The first or second data block is read from or written to the first or second buffer when the first or second storage medium is removed. The digital video recording / reproducing apparatus as described. Digitally encode TV video information to generate an encoded video signal,
Dividing the encoded video signal into data block units of a predetermined size;
In the first period, the first data block is written to the first storage medium, and at the same time, the data block before the first data block is read from the second storage medium,
In the second cycle, the second data block is written to the second storage medium, and at the same time, the first data block is read from the first storage medium,
Recording and playing back the TV video information simultaneously by repeating the first and second periods,
A recording / reproducing method of a digital video recording / reproducing apparatus, wherein the read first and second data blocks are restored to the television video information.

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