JP3552453B2 - Digital video signal recording and playback device - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The invention is a digitalVideo signalRecorded for a long time and recordedVideo signalDigital playbackVideo signalThe present invention relates to a recording / reproducing device.
[0002]
[Prior art]
For example, when recording an image signal obtained by photographing with a monitoring video camera such as a road or an automatic teller machine, it is required to perform recording for a long time of 24 hours or more. For example, in a monitoring system using a moving image (or continuous still images) with a data rate of 4 megabits / second (= 500 kilobytes / second), the amount of data for one day is 500 KB / sec × 60 × 60 × 24 = 43. It can be up to 2 gigabytes. Accordingly, HDDs (hard disk drives) and MODs (magneto-optical disk drives) have a recording capacity of about several gigabytes and are not suitable for such long-time recording. For this reason, for example, in a system using a conventional HDD or the like as disclosed in Japanese Patent Application Laid-Open No. 8-237600, the quality is reduced by lowering the data rate and the overall capacity is suppressed.
[0003]
In addition, a time-lapse VTR (video tape recorder) that enables long-time recording by performing intermittent recording has been conventionally used for recording an image signal of a monitoring video camera.
Further, for example, in a digital data recording apparatus using a DAT (Digital Audio Tape Recorder), a function called RAW (Read After Write) for confirming that data has been reliably recorded is known. The RAW reproduces data recorded by a head other than the recording head during the data recording process, checks recorded data, and retains the recorded data when it is determined that the data is not correctly recorded. The ability to delay and re-record to another location on the tape.
[0004]
[Problems to be solved by the invention]
First, in a data recording device using an HDD, a MOD, etc., if a 1 GB removable HDD is used in order to maintain the image quality, 44 hard disk cassettes are required to record 43.2 GB for one day. However, there is a problem that it takes time to save and organize past data, and the operation cost of the system is high. Further, when the data amount is reduced, there is a problem that the image quality deteriorates.
[0005]
The time-lapse VTR is convenient for storing because a large amount of data can be recorded in one cassette, but has a disadvantage that a necessary scene (moment) for intermittent recording is not recorded in some cases and a part to be seen. The time required for searching and displaying, that is, the access time is long, and when the same portion of the tape is reciprocated many times, the portion is deteriorated (dropout, scratches, noise, etc.). There were drawbacks.
[0006]
Further, in a device having a conventional RAW function, an additional head for reproduction and an additional circuit for preventing a reproduced signal from interfering with a recording signal are required, and a data holding delay for confirming recorded data and re-recording is required. Processing, processing for indicating that data has been re-recorded at another position, processing for reproducing data partially recorded at another position during reproduction, and the like are required. Therefore, the system was complicated and expensive.
[0007]
SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has been made in view of the above-mentioned problems.Video signalProviding a recording / reproducing deviceEyesTarget.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the invention according to claim 1 is a method forIn a digital video signal recording / reproducing apparatus for recording a video signal on a recording medium and reproducing the recorded digital video signal, the digital video signal is recorded on an endlessly recordable disc-shaped recording medium, and the recorded digital video signal is reproduced. A first recording / reproducing means for recording a digital video signal on a tape-shaped recording medium having a longer access time and a larger recording capacity than the disk-shaped recording medium, and reproducing the recorded digital video signal. Means, a first operation of recording the input digital video signal on the disk-shaped recording medium endlessly by the first recording / reproducing means, and a first operation of the signal recorded on the disk-shaped recording medium by the first operation. Each time the data amount reaches a predetermined amount equal to or less than the recording capacity of the disc-shaped recording medium, A second operation of reproducing the recorded signal and recording the signal on the tape-shaped recording medium by the second recording / reproducing means; and reproducing the signal recorded on the tape-shaped recording medium by the second recording / reproducing means. A third operation of recording on the disc-shaped recording medium by the first recording / reproducing means; and a fourth operation of reproducing and outputting a signal recorded on the disc-shaped recording medium by the third operation. And control means for executing the time division by time division. The data amount per unit time of the digital video signal recordable and reproducible by the second recording / reproducing means is per unit time of the digital video signal inputted to the apparatus. The second recording / reproducing means performs the second operation by an intermittent operation, and executes the third operation during a pause of the intermittent operation. That wasFeatures.
[0009]
The invention according to claim 2 is the digital camera according to claim 1.Video signalRecordPlaybackIn the device,When a predetermined scene in a digital video signal recorded on a disc-shaped recording medium is repeatedly reproduced, the reproduced video is repeatedly obtained by the fourth operation.Characterized by.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(1st Embodiment)
FIG. 1 is a block diagram showing a configuration of a digital data recording / reproducing apparatus according to the first embodiment of the present invention. The apparatus according to the present embodiment uses a digital image signal obtained by digitizing an image signal captured by a monitoring video camera as an input digital signal, and records and reproduces the digital signal. This apparatus includes an image compression processing unit 1 for performing image compression processing conforming to the MPEG (Motion Picture Experts Group) standard, a CPU (Central Processing Unit) 4, and a CPU buffer 5 composed of a RAM (Random Access Memory). A control unit 2, an image decompression processing unit 3 that performs image decompression processing corresponding to the image compression processing in the image compression processing unit 1, and a hard disk device (hereinafter, “HDD”) as first recording / reproduction means (or recording / reproduction means) 6), a data tape recorder (hereinafter referred to as “DTR”) 7 as second recording / reproducing means (or recording means or reproducing means), and a DTR buffer 8 for temporarily storing data to be recorded / reproduced by the DTR 7 , The user can record, play, etc. The control unit 2, the HDD 6, and the DTR buffer 8 are interconnected via an interface bus (for example, one that conforms to a SCSI (Small Computer System Interface) 2) 10. ing. The control unit 2 has a ROM (not shown) storing a control program and a RAM for calculation (not shown), and controls the operation of the HDD 6 and the DTR 7 via the interface bus 10 according to the control program stored in the ROM. It is configured to be controllable via
[0018]
As is well known, the HDD 6 writes (records) data on a magnetic disk (first recording medium) called a hard disk, and reads (reproduces) the written data. FIG. 2 is an explanatory diagram for explaining the writing and reading of data by the HDD 6. Data is sequentially written on the magnetic disk in the order of the regions R1, R2, R3, and so on. And the data can be written endlessly. The reading can be performed for each of the regions R1, R2,... Or, for example, the regions R1 to R3 can be collectively read. FIG. 2 is an explanatory diagram, and does not necessarily mean that data is written in a sector-shaped area of the magnetic disk.
[0019]
The DTR 7 has a larger recording (storage) capacity than a magnetic disk and a lower cost per unit data amount, but records data on a magnetic tape (second recording medium) having a long access time, and transfers the recorded data. To play. As the DTR 7, for example, a DTR based on the D-VHS standard is adopted. A DTR conforming to the D-VHS standard can record and reproduce digital data at a data rate of 13.8 Mbps (megabits / second) as a standard, and uses the same mechanism as the VTR of the VHS standard. Data is recorded and reproduced by obliquely scanning the magnetic tape with a magnetic head. Details of the DTR conforming to the D-VHS standard are disclosed in, for example, Japanese Patent Application Laid-Open No. 8-275102. That is, the recording / reproducing data rate DR2 of the DTR 7 is 13.8 Mbps in the present embodiment.
[0020]
FIG. 4 is a diagram for explaining the operation when recording the input digital data. The recording operation of the apparatus shown in FIG. 1 will be described with reference to FIG. The operation described below is executed by the control unit 2 controlling the HDD 6 and the DTR 7.
In FIG. 1, an image compression processing unit 1 performs a compression process on an input image signal, and inputs the processed digital data to the CPU 4 at a data rate DR1 (for example, 1.38 Mbps) (see FIG. 4A). . The CPU 4 transfers the input data to the HDD 6 via the CPU buffer 5 and the interface bus 10 at the data rate DR3 (for example, 20 Mbps), and the HDD 6 writes the data to the magnetic disk (see FIG. 4B). Here, since the data rate DR3 is very large (about 15 times) with respect to the input data rate DR1, every time a predetermined amount of data DA1 (for example, 40 Mbit) is accumulated in the CPU buffer 5 (for each time T1), a short time is set. At T3 (FIG. 4B), writing to the HDD 6 is performed. At this time, the write unit of the HDD 6 corresponds to each of the regions R1, R2,... Shown in FIG.
[0021]
Note that FIG. 4 does not show a state in which recording is started from the time on the vertical axis on the time axis (horizontal axis) (the time of the intersection of the time axis and the vertical axis) in FIG. (A timing at which data is transferred from the HDD 6 to the DTR buffer 8) is extracted and shown.
[0022]
FIG. 3 is a diagram for explaining the conversion of the data rate using the buffer. Data is written to the buffer with a write clock corresponding to the input data rate (DR1 in the case of the CPU buffer 5), and the output data rate (CPU In the case of the buffer 5, the data rate can be converted by reading data from the buffer with a read clock according to DR3).
[0023]
The data written to the HDD 6 is transferred to the DTR buffer 8 at the data rate DR3 during the period in which writing from the CPU buffer 5 to the HDD 6 is not executed and recorded by the DTR 7 every time the total data amount reaches the predetermined amount DA2. (FIGS. 4C and 4D). It is necessary to set the predetermined amount DA2 at most to be equal to or less than the recording capacity (storage capacity) DHDMAX of the HDD 6. However, in the present embodiment, the recording operation and the reproducing operation described later are executed in a time-division manner. The maximum value is set to a value of about 1/2 of the recording capacity DHDMAX. In the example shown by the solid line in FIGS. 4C and 4D, one write operation to the DTR buffer 8 at time T4 is performed for ten write operations to the HDD 6 at time T3 shown in FIG. 4B. Like that. As described above, the recording data rate DR2 by the DTR 7 is 13.8 Mbps, which is lower than the data rate DR3. Therefore, the recording operation of the DTR 7 is performed over the time T2 (> T4). Here, DR2 × T2 = DR3 × T4.
[0024]
Since the DTR 7 uses a magnetic tape as a recording medium, it is preferable to perform a recording operation for a certain time rather than a recording operation for a very short time (about several tens of seconds). For example, FIG. As shown by the dashed line in (d), the writing to the DTR buffer 8 at the time T4 may be performed twice consecutively, while the writing to the HDD 6 at the time T3 is performed 20 times. In this case, by setting the time T4 (= T2 × DR2 / DR3) so that the time T2 = the time T1, the recording from the DTR buffer 8 to the DTR 7 as shown in FIG. The operation and the operation indicated by the broken line) can be continued.
[0025]
It should be noted that times T6 and T7 in FIG. 4C are times (seek times) for switching the read and write processing of the HDD 6, and vary depending on the read address and the write address. Therefore, the times T1 and T4 are set in consideration of the maximum seek time.
[0026]
The data rates DR1 to DR3 and the times T1 to T4 are, for example, DR1 = 1.38 Mbps, DR2 = 13.8 Mbps, DR3 = 20 Mbps, T1 = T2 = 29 seconds, T3 = 2 seconds, and T4 = 20 seconds. In this case, since the minimum capacity of the DTR buffer 8 is given by DR2 × (T2−T4), it is 125 Mbit.
[0027]
Next, the operation at the time of reproduction will be described with reference to FIG. The example shown in the figure shows a case where the DTR 7 is played back for the time T2, and the data rate of the playback data played back from the magnetic tape by the DTR 7 is changed by the DTR buffer 8 and written to the HDD 6 (see FIG. a) (b)). At this time, since the recording of the input data input at the data rate DR1 is also continued, the write operation of the recording data into the HDD 6 at the time T3 at the time T1 is also performed as shown in FIG. Therefore, writing of the reproduction data to the HDD 6 is performed during a period in which writing of the recording data is not executed. As described above, in the present embodiment, about half the capacity DHDREC of the recording capacity DHDMAX of the HDD 6 is used for writing the recording data, and the remaining half capacity DHDPB is used for writing the reproduction data. As described above, writing of recording data and writing of reproduction data can be executed in a time-division manner.
[0028]
The reproduction data written in the HDD 6 is read as shown in FIG. That is, a read operation at time T11 (≦ T3) is performed every time T12, and the read reproduction data is written to the CPU buffer 5 (data flows in the opposite direction to the above-described recording). Then, the reproduction data is output from the control unit 2 to the image decompression processing unit 3 at the data rate DR1 with a delay of the time T15 required for the CPU processing from the end of the immediately preceding write operation of the HDD 6. The image decompression processing unit 3 performs decompression processing of input data, and outputs an image signal after the processing. The output image signal is supplied to, for example, a CRT display and displayed on a screen. In this case, the CPU 4 can compose one screen by arranging the image signal being recorded and the image signal being reproduced, and display the input image signal being recorded and the reproduced image signal side by side on a CRT display. desirable. Of course, the display of only the input image signal during recording, the display of only the reproduced image signal, or the display of an image in which both are displayed may be switched and displayed according to the user's selection. Further, if the reproduced data is overwritten on the confirmed area of the DHDPB after transferring the reproduced data to the DHDPB, data at another position (another time) on the tape can be displayed continuously.
[0029]
If the processing time of the reproduction operation becomes long, the recording data amount exceeds the storage capacity DHDREC for recording data of the HDD 6. Therefore, in the present embodiment, for example, the recording data amount is 80% of the storage capacity DHDREC for recording data. At this time, a caution signal is output to inform the user of this. This attention signal is preferably combined with the output image signal and displayed on a display. The caution signal is not limited to the one displayed on the display, and may be, for example, an audio signal. These controls are performed by, for example, the CPU 4.
[0030]
FIG. 6 is a diagram for explaining a modification of the reproducing operation shown in FIG. In this modified example, the write operation from the DTR buffer 8 to the HDD 6 is executed three times at time T16. Thus, after the user starts the reproduction operation, the output of the reproduction data from the CPU 4 can be actually started from a point in time delayed by the time T15 from the end of the first write operation to the HDD 6 ( Fig. 6 (e). That is, the time from the reproduction instruction by the user to the output of the reproduced image can be reduced as compared with FIG. 5, and the usability can be improved.
[0031]
As described above, in the apparatus according to the present embodiment, the operation of writing input image data to the HDD 6 and the operation of reading data and recording the data in the DTR 7 at a stage when the data written to the HDD 6 is collected to some extent are executed in a time-division manner. Therefore, data input continuously for a long time can be reliably recorded at low cost. In other words, there is no problem that the recording medium becomes enormous as in the case of recording using only the conventional HDD, and there is no problem such as the lack of necessary data at the required moment due to intermittent recording as in a time-lapse VTR. A digital data recording device with high performance can be realized.
[0032]
In addition, since the reproducing operation is always performed via the HDD 6, even when the same portion is repeatedly reproduced, the reproducing process is performed on the HDD 6, so that the magnetic tape of the DTR 7 is not deteriorated. In addition, the access time for repeated reproduction can be greatly reduced.
[0033]
Further, since the reproducing operation is also performed in a time division manner with the recording operation, the recorded data can be reproduced without interrupting the recording operation. Further, the recorded image and the reproduced image can be simultaneously displayed on the display.
In the above data example, since the input data rate DR1 = 1.38 Mbps and the recording / reproducing data rate DR2 of DTR6 = 13.8 Mbps, for example, if the recording operation of DTR7 is performed for about 3 minutes during 30 minutes, Since all input data can be continuously recorded, the MTBF (mean time between failures) of the DTR 7, particularly the life of the magnetic head, can be greatly extended in comparison with the use time.
[0034]
(Second embodiment)
In this embodiment, the hardware configuration and the basic recording / reproducing operation are the same as those of the first embodiment, and an operation for realizing a RAW (Read After Write) function is executed under the control of the control unit 2. It was made. Hereinafter, this operation will be described with reference to FIGS.
[0035]
That is, using the above data example, since DR2 = 10 × DR1, input data for 30 minutes is recorded on a magnetic tape by the DTR 7 in about 3 minutes (FIG. 8, process P1), and the remaining 27 minutes (hereinafter referred to as P1) The DTR 7 is stopped during “non-recording time”. Therefore, in the present embodiment, the data recorded on the magnetic tape during this non-recording time is reproduced (FIG. 8, process P2), the reproduced data is written to the HDD 6, and the data corresponding to the reproduced data remaining in the HDD 6 is handled. The original data to be transmitted and the reproduced data are sent to the CPU 4 (FIG. 7B, time T17), and the CPU 4 checks these data (process P3). Then, as a result of the comparison, when it is confirmed that the data has been accurately recorded on the magnetic tape (when the reproduced data is the original data), the operation is shifted to the stop state, and the recording of the DTR 7 is performed at the next recording operation timing. The operation is performed (process P1). On the other hand, if there is an error in the reproduced data as a result of the collation (when the reproduced data is not the original data), the operation of recording the original data again by the DTR 7 (process P4) and the operation of re-verifying the re-recorded data (Processes P5 and P6) are performed, and the recording operation of the DTR 7 is performed at the next recording operation timing (Process P1). When re-recording, the magnetic tape may be recorded at another position on the magnetic tape in consideration of the possibility that the magnetic tape has a defect such as a flaw.
[0036]
Needless to say, the above-mentioned collation must be executed before the original data recorded in the HDD 6 is overwritten (erased). Therefore, it is desirable that the collation be performed immediately after one recording operation by the DTR 7 is completed.
Here, as described in Japanese Patent Application Laid-Open No. 8-275102, a general DTR performs recording by adding error correction code data to recording data, and performs a data error during reproduction (a relatively small dropout). The error is corrected by an error correction code, and reproduced data is output. The correction capability tends to be higher as the amount of error correction code data is larger. However, a data error due to a large dropout may not be completely corrected by the error correction code described above, resulting in an error in reproduced data.
[0037]
On the other hand, it is possible to specify from the error correction operation that the correction code could not be corrected as represented by the parity code. That is, the presence or absence of an error in the reproduced data, the number thereof, the scale, and the like can be confirmed by the error display in the correction code calculation during the DTR reproducing process.
[0038]
Therefore, a means for confirming the above-mentioned error display is added to the DTR 7, and an error of the reproduced data is detected in the DTR 7 to confirm that the correct recording has been performed. Needless to say, a process for securing an area for writing reproduction data in the HDD 6 and a process of comparing the original data with the reproduction data in the HDD 6 may be omitted.
[0039]
FIG. 8 shows an example in which accurate recording on the magnetic tape is performed by executing the re-recording / re-verification process once. However, when the state of the reproduction data / the original data continues, the re-recording / re-verification is performed. Repeat the process. In that case, the recording operation (for example, a recording operation for 3 minutes for 30 minutes) is not prevented.
[0040]
As described above, according to the present embodiment, a conventionally expensive RAW function can be realized at low cost without adding any hardware.
The time TREC required to record a certain amount of data by the DTR 7 is substantially equal to the time TPB required to reproduce the data. The rate DR2 needs to be at least larger than twice the data rate DR1. Further, when it is found by collation that the data has not been correctly recorded, it takes an additional time TREC to enable the re-recording operation to be performed once. Therefore, the data rate DR2 is at least three times the data rate DR1. It is necessary.
[0041]
(Other embodiments)
The present invention is not limited to the embodiments described above, and various modifications are possible. For example, in the configuration of FIG. 1 described above, the entire storage capacity of the HDD 6 is almost divided into two, and about half of the capacity is used for writing recording data, and about half of the capacity is used for writing reproduction data. However, the present invention is not limited to this, and the input data rate, the total storage capacity of the HDD 6, the continuous playback time, the time interval of the recording operation of the DTR 7, etc. are taken into consideration, and the cost and needs of the apparatus are met. You just need to set it. Further, as shown in FIG. 9A, an HDD 11 may be added to the configuration of FIG. 1, and one may be used for recording data and the other may be used for reproduction data. In the configuration of FIG. 9A, one of the HDDs 6 is dedicated to writing, the other HDD 11 is dedicated to reading, and after writing to the entire area of the HDD 6 is completed, the HDD 11 is dedicated to writing only and the HDD 6 is dedicated to reading. , And thereafter, the write HDD and the read HDD may be switched and used in the same manner.
[0042]
Also, as shown in FIG. 2B, a DTR 12 and a DTR buffer 13 may be added to the configuration of FIG. 1 so that one DTR is used for recording and the other DTR is used for reproduction. . In order to reproduce a tape different from the tape currently being recorded by one DTR, it is necessary to exchange the tape during a period in which no recording operation is being performed and to reproduce the tape. In the case of reproducing the .times., It is necessary to interrupt the reproducing operation when performing the recording operation. However, according to the configuration shown in FIG. 9B, such replacement of cassettes and interruption of the reproducing can be eliminated. .
[0043]
Further, the data amount compression processing in the image compression processing unit 1 is not limited to the one conforming to the MPEG standard, but may be one conforming to the JPEG (Joint Photographic Experts Group) standard. May be used in place of the image thinning-out processing section that performs the above-described processing, or these may be used in combination.
[0044]
In the above-described embodiment, the case where the data rate DR1 after the compression processing is constant is shown. However, the compression rate in the image compression processing unit 1 may be constant and the data rate DR1 may vary depending on the content of the image. Needless to say. The amount of data stored in the CPU buffer 5 is monitored, and the write time interval T1 and the write time T3 for the HDD 6 may be changed as appropriate.
[0045]
Further, the input digital data is not limited to a digitized image signal, and the apparatus of the present invention is applied to a general digital data monitoring apparatus including, for example, text information transmitted / received via a communication line. It may be used for recording and reproduction of general digital data. Alternatively, a combination of digitized image signals and audio signals may be used as input digital data.
[0046]
Further, the HDD 6 may be replaced with a large-capacity semiconductor memory (RAM).
In the above-described embodiment, the control unit 2, the HDD 6, the DTR 7 and the DTR buffer 8 are connected to each other by the interface bus 10, but these components are connected to each other via a communication line. You may do so.
[0047]
In the above-described embodiment, the recording / reproducing apparatus for recording and reproducing digital data is described. However, a recording apparatus having only a recording function or a reproducing apparatus having only a reproducing function may be used.
[0048]
【The invention's effect】
As described in detail above, the digitalVideo signal recording and playbackAccording to the device, input digitalA first operation of recording a video signal endlessly on a disc-shaped recording medium by a first recording / reproducing means, and a data amount of a signal recorded on the disc-shaped recording medium by the first operation is determined by the first operation. Each time a predetermined amount equal to or less than the recording capacity is reached, the signal recorded on the disk-shaped recording medium is reproduced, and the second recording / reproducing means records on a large-capacity tape-shaped recording medium with a longer access time than the disk-shaped recording medium. A second operation of reproducing a signal recorded on the tape-shaped recording medium by the second recording / reproducing means, and recording the signal on a disk-shaped recording medium by the first recording / reproducing means; Operation of reproducing and outputting a signal recorded on a disk-shaped recording medium by the operation ofAre executed in a time sharing manner, so that allVideo signalCan be reliably recorded, and the problem that the amount of recorded recording medium becomes enormous can be avoided.Further, the second operation is performed by the intermittent operation, and the third operation is performed during the pause of the intermittent operation, so that the recorded video signal can be reproduced without interrupting the recording operation. it can.
[0049]
Claim2According to the invention described in the above,When a predetermined scene in a digital video signal recorded on a disk-shaped recording medium is repeatedly reproduced, a reproduced video is obtained repeatedly by the fourth operation. Does not deteriorate, and the access time for repeated playback is greatly reduced.be able to.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a digital data recording / reproducing apparatus according to an embodiment of the present invention.
FIG. 2 is a diagram for explaining endless recording.
FIG. 3 is a diagram for explaining data rate conversion by a buffer;
FIG. 4 is a diagram for explaining a recording operation of the apparatus of FIG. 1;
FIG. 5 is a diagram for explaining a reproduction operation of the apparatus of FIG. 1;
FIG. 6 is a diagram for explaining a reproduction operation of the apparatus of FIG. 1;
FIG. 7 is a diagram for explaining a collation operation of the apparatus of FIG. 1;
FIG. 8 is a diagram for explaining a collation operation and a re-recording / re-collation operation of the apparatus of FIG. 1;
FIG. 9 is a block diagram showing a configuration of a modification of the configuration in FIG. 1;
[Explanation of symbols]
2 control part (control handStage)
4 CPU (Central Processing Unit)
5 CPU buffer
6 Hard disk drive(No.Recording / reproducing means 1)
7 Data tape recorder(No.2 recording and playback handsStage)
8 DTR buffer
10 Interface bus

Claims (2)

Recording a digital video signal input to the recording medium, the digital video signal recording and reproducing apparatus for reproducing a digital video signal the recording,
Record digital video signals on a disk-shaped recording medium that can be recorded endlessly,
First recording / reproducing means for reproducing the recorded digital video signal ;
Longer access time than the disk-shaped recording medium, the digital video signal recorded on the tape-shaped recording medium larger recording capacity, a second recording and reproducing means for reproducing a digital video signal the recording,
A first operation of recording the input digital video signal endlessly on the disc-shaped recording medium by the first recording / reproducing means, and a data amount of the signal recorded on the disc-shaped recording medium by the first operation; A second recording / reproducing unit that reproduces a signal recorded on the disk-shaped recording medium and records the signal on the tape-shaped recording medium by the second recording / reproducing means each time a predetermined amount less than the recording capacity of the disk-shaped recording medium is reached. A third operation of reproducing a signal recorded on the tape-shaped recording medium by the second recording / reproducing means, and recording the signal on the disc-shaped recording medium by the first recording / reproducing means; Control means for executing, in a time-sharing manner, a fourth operation of reproducing and outputting a signal recorded on the disk-shaped recording medium by the operation of 3 , and
The amount of data per unit time of the digital video signal that can be recorded and reproduced by the second recording / reproducing means is sufficiently larger than the amount of data per unit time of the digital video signal input to the apparatus. the recording and reproducing means and executes the second operation by the intermittent operation, the digital video signal recording and reproducing apparatus is characterized in that so as to perform the third operation during the suspension period of the intermittent operation. 2. A digital video signal according to claim 1 , wherein when the predetermined scene in the digital video signal recorded on the disk-shaped recording medium is repeatedly reproduced, the fourth operation is repeated to obtain a reproduced video. Video signal recording and playback device.

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