JP2000228063A - Digital data recording and reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a digital data recording and reproducing device which can correspond to variation in the bit rate of an input packet by monitoring the number of TS packets inputted for one track period, the number of TS packets which can be recorded in the tracks, and the numbers of TS packets which cannot be recorded in the track and overflow, and adaptively using a special reproduction data recording area as a normal reproduction data recording area. SOLUTION: An arrival packet monitoring means 19 for monitoring the number of packets of data inputted for one track period, a record packet monitoring means 20 for monitoring the number of packets inputted for one track period to the number of packets which can be recorded in the track, the number of packets detected by an external control means 22 for setting a recording capacity of each track and the above-mentioned arrival packet monitoring means 19, and the number of packets detected by the record packet monitoring means 20 are compared with each other. Further, when the record capacity set by the external control means 22 is discriminated and the recording area is insufficient to the inputted number of packets, the data are recorded in other recording area.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a digital data recording / reproducing apparatus for recording / reproducing digital data on / from a recording medium, and more particularly to a packetized digital data such as a bit stream conforming to the MPEG2 standard. Can be suitably used for a digital data recording / reproducing apparatus which records the data on a magnetic tape or the like and reproduces it.

[0002]

2. Description of the Related Art In recent years, not only analog TV broadcasting but also digital TV broadcasting has come into practical use. In this digital broadcasting, for example, a technique of performing time-division multiplexing of a plurality of programs (hereinafter, multiprogram) with a transport packet (hereinafter, TS packet) according to the MPEG2 system as a technique for highly efficient encoding of a video signal or the like is used. ing. In addition, such TS
It has been studied to record a multi-program transmitted in packet form on a tape-shaped magnetic recording medium (for example, a digital VTR).

Here, an example of a method for recording the TS packet on a tape-shaped magnetic recording medium will be described with reference to FIG.

[0004] A digital television broadcast receiver (S not shown)
A TS packet of a multi-program received by the TB (set top box) or a part of the multi-program is input through the digital I / F circuit 1. As shown in FIG. 5A, the input TS packet has a 1-byte sync indicating the head of the TS packet and 187
It consists of byte data.

By the way, the TS buffer of each program broadcasted from a broadcasting station is designed so that the buffer memory of the receiver does not cause overflow and underflow when an arbitrary program is selected from multi-programs and received. When recording such data, the TS is transmitted along with the contents of the TS packet.
It is necessary to be able to reproduce the packet interval (TS packet arrival time) during reproduction.

Therefore, the PCR extraction circuit 2 shown in FIG.
Extracts a PCR (program clock reference), which is a program time reference value in an input TS packet, and synchronizes the PCR with a 27 MHz PLL3.
A clock of MHz is generated, and time information (hereinafter, a time stamp) for managing the arrival time of the TS packet is generated by the time stamp generating circuit 4 in accordance with the generated clock. As shown in FIG. 5B, the generated 3-byte time stamp is added to the beginning of the input TS packet after removing the sync (1 byte) of the input TS packet, as shown in FIG.
A TS packet of 0 bytes is configured.

The TS packet to which the time stamp is added is converted to a data format for magnetic tape recording (to be referred to as a sync block hereinafter) by TS-> SB conversion 6, and the data type of the sync block to be described later is MUX8. After adding the indicated 1-byte information, an error correction code is added by an error correction encoder 9 and the data is recorded on a magnetic tape through a recording / reproducing system 10.

The structure of the sync block and the track format on the magnetic tape will be described with reference to FIGS. 6, 7, 8 and 9. First, one sync block is information (hereinafter referred to as SB_
extra_header), that is, information 1 indicating normal reproduction data, special reproduction data, stuffing data, etc.
It consists of bytes and 76 bytes of data. When recording a TS packet, as shown in FIG.
One TS packet is packed into five sync blocks and recorded. If no TS packet arrives when packing into 5 sync blocks, dummy data (hereinafter, stuffing data) is inserted into the intermittent sync block as shown in FIGS. 7 and 8 for packing.

The TS packets packed in the five sync blocks in this way are recorded at predetermined positions for each track as shown in FIG. Tracks include an F0 track, an F1 track, and an F2 track, and four tracks in the order of F0, F1, F0, and F2 according to a pilot signal.
It is repeated in the track cycle.

The main data recording area on the track is composed of 125 sync blocks of sync block numbers 31 to 155, of which the F0 track and the F1 track include:
As shown in FIGS. 9 and 11, there are a normal reproduction data recording area (Normal Play Area) and a special reproduction data recording area (Trick Play Area). After the input TS packet is sync-blocked, it is recorded in a normal reproduction data recording area, and special reproduction data is generated by a special reproduction data processing unit (not shown) and recorded in the special reproduction data recording area.

Here, the special reproduction data recording area of the F0 track is particularly a high-speed search data recording area (hereinafter referred to as TP).
H data area) and the special reproduction data recording area of the F1 track are divided into low-speed search data recording areas (hereinafter, TPL data areas). The number of TS packets that can be recorded on each track is as shown in FIG.

On the other hand, at the time of reproduction, the data reproduced from the recording / reproduction system 10 is subjected to error correction processing by the error correction decoder 11, and then the SB_e added at the time of recording by the DMUX 12.
Normal reproduction data, special reproduction data, and stuffing data are separated based on xtra_header. The extracted normal reproduction data is returned to the structure of the TS packet from the sync block by the SB-> TS conversion circuit 13 and the buffer memory 14 and stored in the buffer memory 15.

The time stamp generating circuit 17 generates a reproduction time stamp synchronized with the track cycle with reference to the value of the time stamp added to the reproduced TS packet. The generated time stamp value is compared with the value of the time stamp added to the reproduced TS packet by the timing adjustment circuit 16, and when the values match, the TS packet is read from the buffer memory 15.

[0014] In this way, the reproduced TS packets are output at the same TS packet interval as at the time of reception.

FIG. 1 shows the relationship between TS packets and time stamps and track positions on a magnetic tape.
This will be described with reference to 2 and 13. FIGS. 12A and 13
The change of the recording time stamp shown in (A) is a value based on the time stamp generating circuit 4 shown in FIG. 4, and the position on the track is recorded at the track cycle of the head on the rotating drum synchronized with the 27 MHz reference clock. The time of the recording time stamp substantially corresponds to the position on the track. Time stamp (for example, 59.94
Hz system), as shown in FIG.
H (0 to 7: 3 bits) and TSL (0 to 18017)
9:18 bits).

Now, FIGS. 12B and 13B
As shown in the figure, during the period of Track 0, 60 packets from the 0th to the 59th arrive continuously, and
Assuming that the 0th and 250th packets arrive intermittently, first in FIG. 12, the number of TS packets arriving during the period of Track0 exceeds the recording capacity of Track0. 12
As shown in (C), the time is extended and Track0 and Tra are extended.
Recorded in ck1.

Also, the time 20 arrives during the period of Track2.
The 0th and 250th TS packets are recorded in Track 2 corresponding to the arrival times. The recording method described above is a method in which a TS packet input intermittently is recorded together with a time stamp in accordance with the arrival time.

On the other hand, in FIG. 13, a TS packet arriving during the period of Track 0 is time-expanded using the buffer memory 7 as shown in FIG.
Track 1 and Track 1
2 is recorded. In addition, 2 arrived during the period of Track 2
The 00th TS packet and the 250th TS packet are stored in the buffer memory 7 from the beginning of Track 3
This is a method in which the 0th and 250th TS packet data are packed forward and recorded continuously.

Hereinafter, the method shown in FIG. 12 is referred to as a pseudo real-time method, and the method shown in FIG.

On the other hand, at the time of reproduction, the time stamp generating circuit 17 shown in FIG.
When the value of each reproduction time stamp shown in (E) matches the value of the time stamp added to the reproduced TS packet, the TS packet is read out from the buffer memory 15 and is read as shown in FIG. As shown in FIG. 13D, TS packets are reproduced at the same packet interval as that at the time of reception.

[0021]

By the way, in digital television broadcasting, the bit rate of each program differs depending on the content of the program transmitted, and the number of packets arriving per unit time usually varies. . In some broadcasts such as DTV, packets continuously arrive at a high bit rate.

Here, for example, it is assumed that a TS packet input as shown in FIG. 14 arrives in the latter half of Track0. Since no TS packet has arrived in the first half of Track0, stuffing data is recorded.
In some cases, all TS packets arriving during the period cannot be recorded in Track0. The TS packet that could not be recorded on Track0 is recorded on the next Track1.

Therefore, Track1 has Track
The TS packet arriving during the period 0, that is, the overflow packet that could not be recorded in Track 0 and the
The TS packet arriving during the period is recorded. However, the number of TS packets arriving during the Track 1 period is T
When the number of recordable packets of track1 is exceeded, or the number of TS packets arriving during Track1 and Tr
The sum of the number of overflow packets of ack0 is Track
If the number of recordable packets exceeds 1, the Track
1 when an overflow occurs and the overflow is sequentially propagated and accumulated such that the corresponding TS packet is recorded in the subsequent Track 2.
4 (A) and 4 (C), the track position of the actually recorded TS packet on the tape is shifted from the recording time stamp synchronized with the track cycle added to each TS packet during recording. FIG. 14 (D),
As shown in (E) and (F), the value of the reproduction time stamp generated by the time stamp generation circuit 17 may not match the value of the time stamp added to the reproduced TS packet. Buffer memory 15
Therefore, there is a possibility that a TS packet similar to that at the time of reception cannot be reproduced without correctly reading the reproduced TS packet.

Further, when the input bit rate instantaneously exceeds the recording rate, a similar problem may occur.

The present invention has been made in view of the above points, and is intended to reduce the number of TS packets input in one track period, the number of TS packets that can be recorded on the track, and the number of TS packets that cannot be recorded on the track and overflow. It is an object of the present invention to provide a digital data recording / reproducing apparatus which can monitor and adaptively use a special reproduction data recording area as a normal reproduction data recording area and can cope with a change in a bit rate of an input packet. I do.

[0026]

Means for Solving the Problems The present invention has the following arrangement to solve the above-mentioned problems.

That is, the digital data recording / reproducing apparatus according to the present invention records digital data in packets of a predetermined data amount on a magnetic tape in a track-like recording pattern having at least two data recording areas. A arriving packet monitoring means for monitoring the number of packets of data input in one track period in a digital data recording / reproducing device for reproducing Recording packet monitoring means for monitoring the number of packets, external control means for setting the recording capacity of each track on the magnetic tape, the number of packets input in one track period detected by the arrival packet monitoring means, Compare the number of packets recordable on the track detected by the monitoring means, and Wherein to determine the recording capacity of each track on the tape which is set by an external control means, for the input number of packets, of the track to be recorded 1
Recording area control means for controlling to record data in another data recording area when the data recording area is insufficient.

Here, the recording area control means determines the number of packets input in one track period detected by the arriving packet monitoring means and the number of packets recordable on the track detected by the recording packet monitoring means. Comparing, further determining the recording capacity of each track on the tape set by the external control means, and if the data recording area of one of the tracks to be recorded is insufficient for the number of input packets, It is preferable to control so that data is recorded in another data recording area of the following track.

Also, an arrival packet monitoring means for monitoring the number of packets of data input in a plurality of track periods, and for the number of packets input in a plurality of track periods, monitoring the number of packets recordable on the plurality of tracks. Recording packet monitoring means, external control means for setting the recording capacity of each track on the magnetic tape, the number of packets input during a plurality of track periods detected by the arriving packet monitoring means, and detection by the recording packet monitoring means The number of packets recordable on the plurality of tracks is compared, the recording capacity of each track on the tape set by the external control means is determined, and the number of packets input per track is determined. If one data recording area of the plurality of tracks to be recorded is insufficient, another data recording area is used. A recording area control means for controlling to record over data, may be provided with a.

Here, the recording area control means determines the number of packets input during a plurality of track periods detected by the arriving packet monitoring means and the number of packets recordable on the plurality of tracks detected by the recording packet monitoring means. , And further determine the recording capacity of each track on the tape set by the external control means, and record one data of the plurality of tracks to be recorded with respect to the number of packets input per the plurality of tracks. When the area is insufficient, it is preferable to control so as to record data in another data recording area of a plurality of tracks following the plurality of tracks.

With this configuration, the number of input packets, the number of packets recordable on the track, and the number of packets overflowing are monitored, and the data recording area of each track on the tape is adaptively controlled. This makes it possible to convert digital data into a tape-like format in response to instantaneous bit rate fluctuations of packets input by a simple method (in case data exceeding the recording rate arrives instantaneously or the number of arriving packets varies). Recording and reproduction can be performed on a magnetic recording medium.

[0032]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of a digital data recording / reproducing apparatus according to the present invention will be described below with reference to FIG. 4, the same components as those of FIG. 4 are denoted by the same reference numerals, and the description thereof will be omitted.

In this embodiment, as shown in FIG. 9, each track includes an F0 track, an F1 track and an F2 track, and the track travels in a cycle of four tracks (F0, F1, F0, F2).
Order). In the recording area of each track, the recording area of each packet is determined in sync block units.

Therefore, the number of packets that can be recorded on one track is, for example, up to 50 when all data recording areas are used for normal reproduction data recording areas as shown in FIG.
TS packet recording is possible. When the special reproduction data is recorded at a predetermined position, the number of TS packets of the normal reproduction data that can be recorded on each track is 38 TS in the F0 track.
The packet is 40 TS packets in the F1 track.

The arrival packet monitor 19 counts the number of packets arriving during one track period. The recording packet monitor 20 counts the number of packets that can be recorded on the track with respect to the number of packets that have arrived, and compares the number of packets that have arrived detected by the arrival packet monitor 19 with the number of packets that can be recorded on the track. The number of packets that could not be recorded on the track, that is, the number of overflow packets, is counted for each track.

The count values are added up for each of the four tracks (F0, F1, F0, F2). The recording area control circuit 21 compares and determines the number of these overflow packets with a predetermined number of overflow packets specified by the external controller 22, and controls the TS-> SB conversion circuit 6 and the multiplexer MUX8 to read the normal reproduced data. And special reproduction data are arranged at predetermined positions of each track as shown in FIG.

Here, in the digital data recording / reproducing apparatus according to claim 1 of the present invention, as shown in FIGS. 2 (B) to 2 (D), each track (Track0 to
k0) a0 (Track0), b0 in the period
(Track1), c0 (Track2), d
It is assumed that the number of 0 (Track 3) TS packets has arrived. These are the number of TS packets arriving during each track period counted by the arrival packet monitor 19.

The number of packets recordable on each track shown in FIG. 2 (G) is a'0 (Track0),
b'0 pieces (Track1), c'0 pieces (Track
2), d'0 (Track 3). These are the number of recordable packets of each track specified by the external controller 22 in advance. The number of packets arriving for each track, the number of overflow packets of the previous track, and the number of packets recordable on the track are recorded packet monitor 2
0, the sum of the number of input TS packets and the number of overflow packets of the previous track is determined by the external controller 22.
If the value exceeds the predetermined value specified in the above, part or all of the special reproduction data recording area of the track to be recorded is allocated to the normal reproduction data recording area, and the number of TS packets that cannot be recorded on the track, that is, overflow By reducing the number of packets and minimizing the propagation and accumulation of the number of overflow packets of each track to a minimum, problems during reproduction are prevented.

Here, for example, as shown in FIG. 2, the TS packet input during the Track 0
Although recorded in ack1, if the number of input TS packets exceeds a predetermined value instructed by the external controller 22, as shown in FIG. , Sync block numbers 131 to 15
5, the special reproduction data recording area for 10 TS packets is allocated to the normal reproduction data recording area.

The TS input during the Track1 period
The packet is recorded in Track2, but the input T
If the sum of the number of S packets and the number of overflow packets of Track1 exceeds a predetermined value, Track
2 of the special reproduction data recording area, the data recording area is controlled so that the special reproduction data recording area for 4 TS packets of sync block numbers 128 to 132 and 150 to 154 is allocated to the normal reproduction data recording area. Reduce the number.

On the other hand, the sum of the number of input TS packets and the number of overflow packets of the previous track is determined by the external controller 2.
When the value falls below the predetermined value designated by the number 2, the special reproduction data is allocated to the predetermined special reproduction data recording area, and the normal reproduction data is allocated to the normal reproduction data recording area.

Next, a digital data recording / reproducing apparatus according to a second embodiment of the present invention will be described.

As shown in FIGS. 3 (B) to 3 (D), a0 (Track0) and b0 (Track0) are respectively provided in each of the tracks (Track0 to Track3) in the T0 period.
1), c0 pieces (Track2), d0 pieces (Track
Assume that the number of TS packets of 3) has arrived. These are the number of TS packets arriving during each track period counted by the arrival packet monitor 19.

As shown in FIGS. 3 (F) and 3 (G), the number of packets that can be recorded on each track of the arriving TS packet is a'0 (Track0) and b'0 (Track1). , C'0 (Track2),
It is assumed that d′ 0 (Track 3). These are the number of TS packets that can be recorded on each relevant track counted by the recording packet monitor 20.

The number of packets that could not be recorded on the track, that is, the number of overflow packets, was calculated from the number of packets arriving for each track and the number of packets that could be recorded on each track, and the total number of overflow packets in the T0 period shown in FIG. The number of packets OF0 is calculated. The value of OF0 and a predetermined value specified by the external controller 22 are compared and discriminated by the recording area control circuit 21, and if the value of OF0 exceeds the predetermined value specified by the external controller, the following is determined. Part or all of the four-track (T1 period) special reproduction data recording area is allocated to the normal reproduction data recording area, and the overflow for the T0 period is recorded.

Here, for example, in FIG. 3 (I), 4TS packets of sync block numbers 128 to 132 and 150 to 154 in the special reproduction data recording area of the F0 track in the T1 period are compared with the overflow packets in the T0 period. The data recording area is controlled so that the special reproduction data recording area is allocated to the normal reproduction data recording area, and the overflowed packet is recorded on the tape.

When the number of overflowed packets falls below a predetermined value specified by the external controller,
Special reproduction data is allocated to a predetermined special reproduction data recording area, and normal reproduction data is allocated to a normal reproduction data recording area, as in the period T2 in FIG.

In the above embodiment, when the special reproduction data recording area is used as the normal reproduction data recording area, the selection of the track to be used and the number of the special reproduction data recording areas are all performed by the external controller 22. It is what is instructed. The recording area on the track shown in FIGS. 2 (I) and 3 (I) has a sync block number 3
Only 1 to 155 (125 sinks) are shown.

In this way, by adaptively controlling the recording area in response to the input of a fluctuating TS packet, it is possible to cope with an instantaneous bit rate fluctuation.

In the subsequent recording process, the error correction encoder 9 adds an error correction code to the recording / reproduction system 11 as in the prior art.
Recorded on the tape.

On the other hand, during reproduction, the operation is the same as that of the reproduction system shown in FIG. That is, the data reproduced from the recording / reproducing system 10 is subjected to error correction processing in the error correction decoder 11, and the head of each sync block SB_
The extra_header is detected to determine the normal reproduction data, the special reproduction data, and the stuffing data, and the normal reproduction data is separated.

The special reproduction data is sent to a special reproduction data processing section (not shown). Normal playback data is SB-
> By the TS conversion circuit 13 and the buffer memory 14,
From the sync block shown in FIG. 6 to 19 shown in FIG.
It is converted into a 0-byte TS packet. The normal reproduction data converted into the packet is input to the time stamp generating circuit 17 ahead of the time stamp of the first 3 bytes of the 190-byte packet, and based on the value, the arrival is synchronized with the track cycle of the rotating drum. A time stamp for time reproduction is generated by the time stamp generation circuit 17.

The timing adjustment circuit 16 compares the value of the generated time stamp for reproducing the arrival time with the value of the time stamp of the reproduced TS packet, and outputs a read start command to the buffer memory 15 when they match, The packet is read and output to a set top box (not shown) via the digital I / F circuit 18. set·
In the top box, the reproduced packet is expanded and demodulated and output as video and audio.

As described above, the present embodiment can be realized with a relatively simple configuration without increasing the capacity of the buffer memory and the like, so that an increase in cost can be suppressed.

[0055]

According to the present invention, the number of input packets per unit time, the number of packets that can be recorded on the track and the number of packets that cannot be recorded on the track are monitored, and the number of packets that can be recorded on the track is adaptively determined by a simple method. It is possible to control the data recording area of each track on the tape, and to cope with an instantaneous bit rate fluctuation of an input packet (an arrival of data exceeding the recording rate instantaneously).
As a result, the data recording area of the recording medium can be more effectively utilized.

Also, by monitoring the number of packets per unit time of the packets input collectively for a plurality of tracks, the number of packets that can be recorded on the plurality of tracks, and the number of packets that cannot be recorded on the plurality of tracks, The control burden can be reduced.

Further, since it can be realized with a relatively simple configuration, it is possible to suitably cope with downsizing and weight reduction of equipment.

[Brief description of the drawings]

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

FIG. 2 is a diagram illustrating a first embodiment of a packet data recording method according to the present invention.

FIG. 3 is a diagram illustrating a packet data recording method according to a second embodiment of the present invention.

FIG. 4 is a block diagram illustrating an example of a digital data recording / reproducing device that records bit stream data.

FIG. 5 is a diagram showing a configuration of a packet.

FIG. 6 is a diagram showing a configuration when a packet is packed in a sync block.

FIG. 7 is a diagram showing a configuration when all five sync blocks are packed with stuffing data.

FIG. 8 is a diagram showing a configuration when a part of five sync blocks is packed with stuffing data.

FIG. 9 is a diagram showing recording areas for normal reproduction data and special reproduction data in each track on the tape.

FIG. 10 is a diagram showing the number of recordable TS packets for each track.

FIG. 11 is a diagram showing a recording position of special reproduction data on a track.

FIG. 12 is a diagram showing an example of a relationship between packets and time stamps recorded and reproduced on a tape-shaped magnetic recording medium and recording track positions on the tape.

FIG. 13 is a diagram showing an example of the relationship between packets and time stamps recorded and reproduced on a tape-shaped magnetic recording medium and recording track positions on the tape.

FIG. 14 is a diagram showing an example of a relationship between packets recorded and reproduced on a tape-shaped magnetic recording medium and recording track positions on the tape.

[Explanation of symbols]

 1: Digital I / F circuit (input) 2: PCR extraction circuit 3: 27 MHz PLL 4: Time stamp generation circuit (recording) 5: Time stamp addition circuit 6: TS → SB conversion circuit 7: Buffer memory 8: MUX (multiplexer) 9: Error correction encoder 10: Tape recording / playback system 11: Error correction decoder 12: DMUX (demultiplexer) 13: SB → TS conversion circuit 14: Buffer memory 15: Buffer memory 16: Timing adjustment circuit 17: Time stamp generation circuit (reproduction) 18: Digital I / F circuit (output) 19: Arrival packet monitor 20: Record packet monitor 21: Recording area control circuit 22: External controller

 ────────────────────────────────────────────────── ─── Continued on the front page F term (reference) 5C053 FA02 FA14 FA20 FA21 GA11 GB01 GB05 GB38 HA13 HA29 JA24 KA05 KA21 KA24 LA06 5D044 BC01 CC03 DE03 DE12 EF03 GK04 GK07 GK12

Claims (4)

[Claims] 1. A digital data packetized in a predetermined data amount is recorded on a magnetic tape in a track-like recording pattern having at least two data recording areas,
In a digital data recording / reproducing apparatus for reproducing the data, an arriving packet monitoring means for monitoring the number of packets of data input in one track period; Recording packet monitoring means for monitoring the number of packets; external control means for setting the recording capacity of each track on the magnetic tape; number of packets input in one track period detected by the arriving packet monitoring means; Compare the number of packets recordable on the track detected by the packet monitoring means, further determine the recording capacity of each track on the tape set by the external control means, for the number of packets input, If one data recording area of the track to be recorded is insufficient, data is recorded in another data recording area. A digital data recording / reproducing apparatus, comprising: recording area control means for controlling recording. 2. The recording area control means compares the number of packets input in one track period detected by the arriving packet monitoring means with the number of packets recordable on the track detected by the recording packet monitoring means. Further, the recording capacity of each track on the tape set by the external control means is determined, and if one data recording area of the track to be recorded is insufficient for the number of input packets, the next 2. The digital data recording / reproducing apparatus according to claim 1, wherein control is performed such that data is recorded in another data recording area of a track following the track. 3. A digital data packetized with a predetermined data amount is recorded on a magnetic tape in a track-like recording pattern having at least two data recording areas,
In a digital data recording / reproducing apparatus for reproducing the data, arriving packet monitoring means for monitoring the number of packets of data input in a plurality of track periods, and recording on the plurality of tracks with respect to the number of packets input in a plurality of track periods Recording packet monitoring means for monitoring the number of packets, external control means for setting the recording capacity of each track on the magnetic tape, the number of packets input during a plurality of track periods detected by the arriving packet monitoring means, The number of packets that can be recorded on the plurality of tracks detected by the recording packet monitoring unit is compared, and the recording capacity of each track on the tape set by the external control unit is determined. One data recording area of the plurality of tracks to be recorded is And a recording area control means for controlling to record data in another data recording area, if necessary. 4. The recording area control means determines the number of packets input during a plurality of track periods detected by the arriving packet monitoring means and the number of packets recordable on the plurality of tracks detected by the recording packet monitoring means. Then, the recording capacity of each track on the tape set by the external control means is determined, and one data recording area of the plurality of tracks is recorded with respect to the number of packets input per the plurality of tracks. 4. The digital data recording / reproducing apparatus according to claim 3, wherein when the number of tracks is insufficient, control is performed such that data is recorded in another data recording area of a plurality of tracks subsequent to the plurality of tracks.