JPH08124306A - Method and device for digital signal recording - Google Patents

Abstract

PURPOSE: To record digital compressed video signals by providing two pairs of opposing heads on the cylinder of a VTR which records analog video signals by a rotary head on a recording tape made of oxidized magnetic materials and simultaneously recording two channel tracks. CONSTITUTION: A 212 byte block including synchronization, ID and parity bits is set and 188 byte transmission packets for MPEG 2 digital compression video signals are stored. 139 packets are made into one group and a data recording region 60 which is equivalent to one track is formed by 151 blocks to that control signals such as editing information and a longitudinal parity are added. A track includes an added information recording region 30 for audio signals, a subcode recording region 70 for time and program information and various margins and the track is 181 blocks long. When the packet transmission rate of the MPEG 2 is approximately 25Mbps, a recording is performed with a cylinder revolving speed of 1,800rpm and a 18.5Mbps per channel rate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital signal recording method and apparatus for recording digital signals, and more particularly to a method and apparatus for recording digital compressed video signals.

[0002]

2. Description of the Related Art A home digital V for compressing and recording a digital video signal on a magnetic tape using a rotary head.
TR is Nikkei BP "Data compression and digital modulation" 1
It is described on pages 37 to 150. In this VTR,
Using a dedicated cassette and high-performance metal vapor deposition tape, 2
A compressed digital video signal of 4.948 Mbps or more and a digital audio signal of 2 channels (1.536 Mbps) are transferred at a cylinder rotation speed of 9000 rpm and a recording rate of 4
It is recorded at 1.85 Mbps.

[0003]

However, the conventional VTR for recording analog video signals has a cylinder rotation speed of 180.
It is 0 rpm. Further, it is difficult to record a digital signal having a recording rate of 20 Mbps or more with an oxide tape. Therefore, it is impossible to directly record the signal of the household digital VTR, and compatibility with the conventional analog VTR is not taken into consideration in the cassette and the tape used.

An object of the present invention is to provide a conventional analog recording VT.
It is an object of the present invention to provide a digital signal recording method and apparatus compatible with a conventional analog recording VTR in consideration of the magnetic tape used in R.

[0005]

The above object is to provide four rotary heads for recording, a means for dividing a digital compressed video signal of 25 Mbps and a digital audio signal of 1.6 Mbps into two channels, and the above-mentioned channels. The divided signal is divided into a predetermined number of symbols, a synchronizing signal, a control signal and an error detection / correction code are added to form a block, and a predetermined number of the blocks form a digital signal recording area of one track. This can be achieved by having means.

[0006]

An input 25 Mbps digital compressed video signal and 1.6 Mbps digital audio signal are divided into two channels, and a sync signal, a control signal and an error detection and correction code are added to a predetermined number of symbols to form a block. However, the recording rate per channel is set to 2 by forming the recording area of one track by the predetermined number of blocks.
Since it can be set to 0 Mbps or less, it becomes possible to record with a conventional analog VTR.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a recording pattern of one track on a magnetic tape. Reference numeral 30 is an additional information recording area such as an audio signal, 60 is a data recording area for recording a digital compressed video signal, 70 is a subcode recording area for recording subcodes such as time information and program information, 20, 24 and 28.
Is the preamble of each recording area, 40, 44 and 48 are the postambles of each recording area, 50, 5
Reference numeral 5 is a gap between the respective recording areas, and 10 and 15 are margins at the track ends. As shown in FIG. 1, by providing a preamble, a postamble, and a gap in each recording area, each recording area can be post-recorded independently.

FIG. 2 shows a block configuration of each recording area. FIG. 2A shows a block configuration of the additional information recording area 30 and the data recording area 60. In FIG. 2A, 200 is a synchronizing signal, 210 is ID information, 220 is additional information or compressed video signal data, and 230 is a parity (C1 parity) for error correction. Sync signal 2
00 is 2 bytes, ID information 210 is 4 bytes, data 2
20 is composed of 195 bytes and parity 230 is composed of 11 bytes, and one block is composed of 212 bytes.

FIG. 2B shows a block configuration of the subcode recording area 70. In FIG. 2B, 200 is a synchronization signal, 210 is ID information, 270 is subcode data, and 280 is a parity (C1 parity) for error correction. In the block of the subcode recording area, the synchronization signal 200 and the ID information 210 are the same as those in FIG. 2A, the data 270 is 42 bytes and the parity 280 is 5 bytes. One block in the subcode recording area is composed of 53 bytes, which is ¼ of one block in the data recording area shown in FIG. In this way, the block configurations of the subcode recording area and the additional information / compressed video signal data recording area are set to have an integer ratio, and the synchronization signal 200 and the ID information 210 have the same configuration in each recording area. The same circuit can perform signal processing such as time block, sync signal, ID information generation, and sync signal and ID information detection during reproduction.
Further, by making the block configuration of the subcode recording area 70 smaller than the block configurations of the other recording areas, it is possible to improve the detection capability during high speed reproduction.

Next, the ID information 210 will be described. FIG. 3 is a diagram showing the configuration of the ID information 210.
In FIG. 3, 300 is a region code, 310 is a track address, 320 is a block address within one track,
330 is ID data, 340 is the area code 300,
It is a parity for detecting an error in the track address 310, the block address 320, and the ID data 330. Area code 300 is 2 bits, track address 3
10 is 6 bits, block address 320 is 8 bits,
The ID data 330 is composed of 8 bits and the parity 340 is composed of 8 bits. Here, the area code 300 is for identifying each recording area. For example, "00" in the data recording area 60, "10" in the additional information recording area 30, and "1" in the subcode recording area 70 in FIG.
Alternatively, two kinds of area codes “00” and “01” may be assigned to the data recording area 60 and used for different data identification such as data for variable speed reproduction. This is an address for identifying the recorded track, for example, the address is changed in units of 1 track and 2 tracks, and in this embodiment, 64 tracks or 128 tracks can be identified by a 6-bit address. Is an address for identifying a block in each recording area, for example, 0 to 150 in the data recording area 60, 0 to 14 in the additional information recording area 30, and 0 in the subcode recording area 70.
-11. The ID data 330 will be described later in detail.

The parity 230 of the additional information and compressed video signal recording area shown in FIG. 2A is the area code 300 and the track address 310 in the above-mentioned ID information 210.
And the block address 320 and the data 220 are added. As a result, it is possible to improve the detection capability and reliability of the block address and the like during reproduction.

Next, the data structure of one track in each recording area will be described. FIG. 4 is a diagram showing the data structure of one track of the compressed video signal data recording area 60.
The sync signal 200 and the ID information 210 are omitted. The compressed video signal data recording area 60 is composed of 151 blocks, and data such as a compressed video signal is recorded in the first 139 blocks. A control signal 400 such as edit information of a video signal to be recorded is recorded in the first 7 bytes of the 139 block, and compressed video signal data 410 is recorded in the subsequent 188 bytes. In MPEG2, the standardization of the compression method of which is progressing, the transmission packet is composed of 188 bytes, and according to the method of the present invention, it is possible to record with good consistency. The 12 blocks after the 139 block have parity (C2 parity) for error correction.
Record 420.

FIG. 5 is a diagram showing the data structure of one track of the additional information recording area 30. The synchronization signal 20
0 and ID information 210 are omitted. The additional information recording area 30 is composed of 15 blocks, and the information 500 related to a video signal such as an audio signal is recorded in 9 blocks.
Parity (C2 parity) 510 for error correction is recorded in the subsequent 6 blocks. Parity 510
For example, the parity of 6 × 2 = 12 blocks is added to the 15 × 2 = 30 blocks of 2 tracks. If one byte from each block, that is, 30 bytes and 12 bytes of parity are added, the C2 parity configuration of the compressed video signal recording area 60 can be made the same and the processing can be shared. . In the present embodiment, an example in which the parity is added to the data of 2 tracks has been described, but the present invention is not limited to this, and the parity is added to the data of m tracks (m is a positive integer), and The same effect can be obtained if the parity configurations of the recording areas are the same.

In this embodiment, when two sets of opposed heads are provided on the cylinder and two-channel recording is performed at a cylinder rotation speed of 1800 rpm, a compressed video signal recording area 60 has a compressed video signal of about 25 Mbps (25.08672 Mbps). Data can be recorded. Further, a control signal of about 934 kbps (934.08 kbps) can be recorded in the recording area. In the additional information recording area 30, additional information of about 1.7 Mbps (1.6848 Mbps) can be recorded. Therefore, the quantization frequency is 48 kHz
z, 16-bit quantization bit, 2-channel PCM
A voice signal (1.536 Mbps) can be recorded. FIG. 6 shows a recording pattern on the magnetic tape at the time of two-channel recording using two sets of opposed heads at the cylinder rotation speed of 1800 rpm. In FIG. 6, 600 is a magnetic tape, and 610 is one track shown in FIG. In FIG. 6, 1A, 1B, 2A, and 2B represent two sets of opposed heads for recording. For 2-channel recording, 1 cylinder
Two tracks are recorded at / 2 rotations.

Next, the ID data 330 included in the above-mentioned ID information 210 will be described. First, FIG. 7 shows ID data 330 in the compressed video signal data recording area 60.
Shows the configuration of. In the ID data 330, 5 bytes of 5 blocks form one piece of information. By multiplexing this information in 151 blocks of the compressed video signal data recording area 60 30 times, the detection capability during reproduction is improved.
It should be noted that, since the present embodiment has 151 blocks, one block remains when multiple recording is performed, but it does not matter if any one block of the ID data 330 is recorded. The 5 blocks of data are composed of 7 types of data, ID-1 to ID7.

ID-1 defines the recording format of the compressed video signal data recording area 60. That is, this embodiment can support a plurality of types of recording formats, and the identification can be performed by ID-1.

ID-2 defines the recording mode.
In this embodiment, the maximum recording capacity is shown. As described above, in the present embodiment, when two channels are recorded at the cylinder rotation speed of 1800 rpm, a compressed video signal of about 25 Mbps at the maximum can be recorded. Therefore, when recording a signal with a transmission rate lower than that, dummy data is recorded in the remaining portion. However, when the transmission rate is considerably low, the dummy data increases and the recording efficiency decreases. Therefore, in this embodiment, a plurality of recording modes are provided so that a plurality of types of transmission rates can be supported. That is, if recording is performed once every two head scans, a maximum signal of about 12.5 Mbps can be recorded. Further, if recording is performed once every four head scans, it is possible to record a signal at a maximum of about 6.25 Mbps. In this case, the track patterns on the tape are almost the same by setting the tape feed speed to 1/2 and 1/4 respectively in the 25 Mbps mode. Similarly, the maximum recording capacity can be set to 1 / n of 25 Mbps. That is, recording is performed once every n times of head scan, and the tape feeding speed is set to 1 / n. in this way,
By having a plurality of recording modes, it is possible to identify the transmission rate of recording data and perform recording in the optimum recording mode. In this method, the recording rate when recording on the tape is the same in any mode. Therefore, only one type of signal processing, especially analog circuit, is required.
This has the effect of simplifying the circuit configuration. Then, the recording mode is recorded in ID-2. For example, ID
-2 is "1" at 25 Mbps mode, 12.5 Mbps
Set the mode to “2” and the 6.25 Mbps mode to “4”. At the time of reproduction, ID-2 is read and the tape feeding speed and the like are set to predetermined values.

ID-4 defines the time axis compression mode and the time axis compression rate of the recording data. This corresponds to a system in which a digital signal is compressed on the time axis, transmitted in a short time, recorded, and then expanded on the time axis for reproduction. For example, ID-4 is "1" when the time axis compression is not performed, "2" when the time axis compression rate is 2 times, and "2" when the time axis compression rate is 4 times.
4 ".

ID-5 indicates whether or not the transmission rate of the data to be recorded is synchronized with the cylinder rotation frequency. For example, if synchronized, set ID-5 to "
1 ", when not synchronized, it is set to" 0. "When synchronized, the amount of data recorded on each track can be made constant, and when not synchronized, the amount of recorded data changes depending on the track. Need to let.

ID-6 defines the amount of data recorded on one track. For example, to record a signal of 24 Mbps, in the recording mode "1", 25000 per track
You only need to record bytes of data. Also, 9.6 Mbp
In order to record the s signal, 20,000 bytes of data may be recorded per track in the recording mode "2". In the above example, the transmission rate of the data to be recorded is synchronized with the number of rotations of the cylinder, but when it is not synchronized, the amount of data to be recorded may be controlled in units of two tracks, for example.

ID-3 and ID-7 are reserved. Dummy data (for example, "0") is recorded in this portion. If there is an item that should be entered later as ID information, it can be added to this part.

As described above, by controlling the recording mode and the amount of data to be recorded in one track according to the transmission rate of the data to be recorded, it is possible to easily cope with a plurality of data transmission rates. During playback,
First, the ID data 330 may be detected to identify the recording mode and the like, the mode of the reproduction signal processing circuit may be set, and the reproduction processing may be performed.

FIG. 8 shows the structure of the ID data 330 in the additional information recording area 30. The ID data 330 of the additional information recording area 30 corresponds to the data recording area 60 shown in FIG.
The ID data 330 has the same structure, and 5 blocks and 5 bytes form one piece of information. This information is multiplexed and recorded in 15 blocks of the additional information recording area 30 three times to improve the detection capability during reproduction. The data of 5 blocks is made up of the same seven types of data as ID-1 to ID-7 shown in FIG. The description of ID-1 to ID-7 is the same as in the case of the data recording area 60, and will be omitted here.

FIG. 9 shows the structure of the ID data 330 in the subcode recording area 70. Unlike the ID data 330 in other recording areas, information is constructed by 1 byte in 1 block. ID data 330 of the subcode recording area 70
Records information indicating the beginning of the program and information for skip reproduction. One block of data is ID-
It consists of five types of data: 1, 3, 8, 9, 10. ID-1 and ID-3 are the same as the other recording areas, and the description thereof is omitted here.

ID-8 defines the priority.
This indicates the support level of ID data and subcode. For example, during variable speed reproduction, it is indicated whether the sub-code information is used or only ID-9 and 10 described later are used.

ID-9 defines the start position of the program. For example, if the start position of the program is set, ID-9 is set to "1", and if not, set to "0" and recorded.

ID-10 defines the skip start position. For example, if the start position of the portion to be skipped is set, ID-10 is set to "1", and if not, it is set to "0" and recorded.

In the subcode recording area 70, the same data is recorded in all blocks in one track. As a result, it is possible to improve the detection capability during high-speed search.

FIG. 10 shows the structure of the data 270 in the subcode recording area 70 shown in FIG. 2B. Data 27
0 is a pack 101 composed of 7 bytes as data
0 to 1060 is recorded. This pack 1010-1
The structure of 060 is shown in FIG. Of the 7 bytes that make up the pack, byte 0 is an item indicating the content of information to be recorded in the pack, and bytes 1 to 6 are sub-data indicating the information. By switching items, multiple types of information can be recorded. FIG. 12 shows an example of the configuration of a pack when recording time information. Subcode recording area 70
As described above, the block configuration is made small so as to be compatible with high speed reproduction. Therefore, the pack recorded in this area is suitable for recording the information necessary for high-speed search. Further, since post-recording is possible, the user can add the recorded program number or the like later, for example.

The control information 400 in the data recording area 60 shown in FIG. 4 is also recorded in the pack format composed of 7 bytes shown in FIG. In this way, the pack of the data 270 in the subcode recording area 70 and the data recording area 60
By making the packs of the control information 400 of No. 1 have the same format, the pack processing circuits can be made common. The data recording area 60 can also be post-recorded, but the control information 400 cannot be post-recorded without rewriting the data 410.
Therefore, the pack recorded in the control information 400 is the information accompanying the data 410, and is suitable for recording the information that the user does not want to arbitrarily rewrite. For example, by recording copy information in this area, copyright protection can be performed.

Here, the preamble and postamble shown in FIG. 1 are 170 bytes, the gap is 296 bytes, and the margin is 466 bytes. As a result, FIG.
The total of margin and preamble is 636 bytes, total of postamble, gap and preamble is 636 bytes, and total of postamble and margin is 6 bytes.
It will be 36 bytes. This corresponds to 3 blocks when converted in the block shown in FIG. In this way, if the space between the additional information recording area 30, the data recording area 60, and the subcode recording area 70 is set to an integral multiple of the data block length, the recording area can be managed in block units, and The load on the processing circuit can be reduced.

In the above structure, one track has 38372.
It becomes a bite (181 block), and the cylinder speed is 18
At 00 rpm, the recording rate per channel is 1.
It will be 8.41856 Mbps, that is, 20 Mbps or less. In addition, the cylinder speed is 1800 / 1.001r
With pm, the cylinder speed can be made completely the same as the conventional analog recording VTR. In this case, 2
5.0617 Mbps digital compressed video signal and 1.
Capable of recording 6831 Mbps digital audio signals,
Recording rate is 18.4002 Mbps per channel
Becomes

Next, an embodiment of a digital signal recording apparatus for recording by the recording method of the present invention will be described with reference to FIG. In FIG. 13, reference numeral 1300 is an analog video signal input terminal, 1305 is a digital data input terminal, 1310 is an analog video signal recording processing circuit, 13
Reference numeral 20 is an interface circuit, 1330 is a data separation circuit, 1335 is a recording signal detection circuit for detecting the transmission rate of the recording signal, the type of signal, etc., 1340 is a digital data recording processing circuit for generating the recording signal shown in FIG.
Reference numeral 50 is a control circuit such as a microprocessor for controlling the recording mode, 1355 is a timing generation circuit for generating a reference signal such as cylinder rotation, 1360 is a servo circuit for controlling cylinder rotation and tape feed speed, 1370 is a cylinder, 1375 is a magnetic tape, 1
A, 1B, 2A and 2B are magnetic heads for recording digital signals, and 1C and 2C are conventional magnetic heads for recording analog signals.

The digital data input from the input terminal 1305 is sent to the data separation circuit 1330 and the recording signal detection circuit 1335 via the interface circuit 1320. The recording signal detection circuit 1335 detects the type of signal and the like based on the information added to the input digital data, and outputs the result to the control circuit 1350. The control circuit 1350 determines the recording mode according to the detection result, and the digital data recording processing circuit 13
40, data separation circuit 1330 and servo circuit 1360
Set the operation mode of. When the transmission rate of the input signal is synchronized with the cylinder speed, the timing generation circuit 1
355 outputs a clock synchronized with the input signal, and performs signal processing at that timing. At the same time, the timing generation circuit 1355 generates a reference signal such as cylinder rotation. The data separation circuit 1330 separates the input digital data into a video signal, an audio signal, and other control signals, and inputs them to the digital recording processing circuit 1340. The digital recording processing circuit 1340 adds the error correction code, ID information, and subcode of each recording area according to the recording mode judged by the control circuit 1350, and generates the recording signal shown in FIG. The recording signal generated by the digital recording processing circuit 1340 is transferred to the cylinder 13
70 for digital signal recording magnetic heads 1A, 1B,
2A, 2B and recorded on the magnetic tape 1375.

On the other hand, when recording a conventional analog video signal, the analog video signal input from the input terminal 1300 is subjected to predetermined signal processing by the analog video signal recording processing circuit 1310 to record the analog signal on the cylinder 1370. Tape 1375 using the magnetic heads 1C and 2C for use
Record above. Although it is not shown in the drawing, whether the analog signal is recorded or the digital signal is recorded can be discriminated at the time of reproduction by recording the discrimination signal in the CTL signal recording area for tracking. it can.

FIG. 14 is a diagram showing an embodiment of a digital signal reproducing apparatus for reproducing a signal recorded by the recording method of the present invention. In FIG. 14, reference numeral 1400 is an analog signal reproduction processing circuit, 1410 is a digital signal reproduction processing circuit for reproducing data and ID information from a reproduction digital signal, 1420 is a data processing circuit, and 1430 is an output clock for generating an output clock of reproduction data. A generation circuit, 1440 is an interface circuit, 1450 is an analog reproduction signal output terminal, and 1455 is a digital reproduction signal output terminal.

At the time of reproduction, first, whether the signal is an analog signal record or a digital signal record is discriminated from the discrimination signal recorded in the CTL signal recording area at the time of recording. In the case of digital signal recording, first, a reproducing operation is performed in an arbitrary reproducing mode, and the digital reproduction processing circuit 1410 detects the ID information. Then, the control circuit 1350 determines the recording mode, sets the operation mode of the digital reproduction processing circuit 1410 and the servo circuit 1360 to a predetermined reproduction mode, and performs the reproduction operation. The cylinder 1370 and the magnetic tape 1375 are the servo circuit 1
A predetermined cylinder rotation speed and tape feed speed are controlled by 360. Magnetic heads 1A, 2 on cylinder 1370
The signals reproduced from the magnetic tape 1375 by A, 1B, and 2B are sent to the digital reproduction processing circuit 1410. In the digital reproduction processing circuit 1410, the sync signal is detected from the input signal, error correction is performed, and the data,
The data processing circuit 142 reproduces the additional information and the subcode.
Output to 0. The data processing circuit 1420 restores the reproduced signal to the signal format at the time of recording and sends it to the interface circuit 1440. However, in the case of recording in the time base compression mode, the tape feed speed is set to 1 / the compression ratio at the time of recording obtained from the ID information, and the reproduced signal is included in the ID information by the digital reproduction processing circuit 1410. Based on the track address and block address to be recorded, the data is rearranged and output in the same order as at the time of recording. Interface circuit 1440
Then, the reproduced data is output from the digital signal output terminal 1455 on the basis of the clock generated by the output clock generation circuit 1430. The data may be output separately from the data and the additional information, or may be multiplexed and output.

When reproducing a conventional analog-recorded signal, the magnetic heads 1C and 2C on the cylinder 1370 are used.
The signal reproduced by the analog reproduction processing circuit 1400
Performs predetermined signal processing with the analog signal output terminal 145
Output from 0.

As described above, according to the method of the present invention, a digital video signal of about 25 Mbps at the maximum and about 1.
6 Mbps additional information (such as audio) is recorded in 2 channels with a recording rate of 20 Mbps per channel.
It becomes possible to record in the following. This enables digital VT compatible with conventional analog recording VTR.
R can be realized.

[0041]

As described above, according to the method of the present invention, a maximum recording rate of about 25 Mbps of a digital video signal and a maximum of about 1.6 Mbps of additional information (such as audio) can be recorded in two channels at a recording rate per channel. 20 Mb
It is possible to record at ps or less. In addition, by setting a recording area formed of a preamble, a postamble, a gap, a margin, and the like between recording areas to be an integral multiple of a block, each recording area can be easily managed in block units. .

[Brief description of drawings]

FIG. 1 is a recording pattern diagram of one track according to an embodiment of the present invention.

FIG. 2 is a block configuration diagram of each recording area.

FIG. 3 is a configuration diagram of ID information 210.

FIG. 4 is a data configuration diagram of one track in a data recording area 60.

5 is a data configuration diagram of one track in an additional information recording area 30. FIG.

FIG. 6 is a recording pattern diagram on a magnetic tape according to the present invention.

7 is a configuration diagram of ID data 330 in the data recording area 60. FIG.

FIG. 8 is ID information 330 in the additional information recording area 30.
FIG.

9 is a configuration diagram of ID information 330 in a subcode recording area 70. FIG.

10 is a configuration diagram of data 270 in a subcode recording area 70. FIG.

11 is a configuration diagram of packs 1010 to 1060. FIG.

FIG. 12 is a configuration diagram of a pack when time information is recorded.

FIG. 13 is an embodiment of a digital signal recording device for recording by the recording method of the present invention.

FIG. 14 is a block diagram of a digital signal reproducing apparatus for reproducing a signal recorded by the recording method of the present invention.

[Explanation of symbols]

 30 ... Additional information recording area 60 ... Data recording area 70 ... Subcode recording area 200 ... Sync signal 210 ... ID information 220 ... Data 230 ... C1 parity 300 ... Area code 310 ... Track address 320 ... Block address 330 ... ID data 400 ... Control information 410 ... Video signal data 420 ... C2 parity 500 ... Additional information data 510 ... C2 parity 1370 ... Cylinder 1375 ... Magnetic tape 1A, 2A, 1B, 2B, 1C, 2C ... Magnetic head 1320 ... Interface circuit 1335 ... Recording system detection Circuit 1350 ... Control circuit 1340 ... Digital recording signal processing circuit 1355 ... Timing generation circuit 1360 ... Servo control circuit 1410 ... Digital reproduction signal processing circuit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Keiji Noguchi 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Ltd.

Claims (9)

[Claims] 1. A digital signal is divided into a predetermined number of symbols, and a sync signal, a control signal and an error detection and correction code are added to each of the digital signals divided into the predetermined number of symbols to form a block format, and a predetermined number of In the digital signal recording method of forming a digital signal recording area of one track by the block and simultaneously recording a plurality of tracks on a magnetic recording medium by a rotary head, at least the first digital signal is recorded in the recording area of the one track. It consists of a recordable first recording area and a second recording area capable of recording a second digital signal. The recording area is provided with a preamble, a postamble and a gap between the recording areas, and one track. Margins are provided at both ends of the sum of the margin and the preamble, the preamble and the gap. Digital signal recording method comprising the sum of postamble, that the sum of post-amble and margin is an integral multiple of each of the block length. 2. The digital recording apparatus according to claim 1, wherein the recording area is provided with a third recording area capable of recording control information related to the first digital signal or the second digital signal. Signal recording method. 3. The error detection / correction code added to each of the digital signals divided into the predetermined number of symbols has the same structure of added parity in the first recording area and the second recording area. 2. The digital signal recording method according to claim 1, which is characterized in that. 4. The error detection and correction code added to each of the digital signals divided into the predetermined number of symbols has a parity of m () in both or one of the first recording area and the second recording area. 2. The digital signal recording according to claim 1, wherein the parity of the first recording area and the second recording area are made the same by adding m to a track data. Method. 5. The recording mode is set according to a transmission rate of a digital signal to be recorded, and the recording rate is set so that a recordable transmission rate is higher than a transmission rate of the digital signal to be recorded. The digital signal recording method according to claim 1. 6. The rotary head comprises at least four magnetic heads, the rotation speed is about 1800 rpm, and two heads simultaneously record the recording area for two tracks. Digital signal recording method. 7. The recording mode is set in units of 1 / n (n is a positive integer) of the maximum recordable transmission rate, and 1 / n
2. The digital signal recording method according to claim 1, wherein in the recording mode, the recording is performed once every n times of the rotary head scan, and at the same time, the tape feeding speed is set to 1 / n. 8. The control signal includes at least a first control signal indicating a recording mode at the time of recording and a second control signal indicating the number of the digital signals recorded in the recording area. The digital signal recording method according to claim 1. 9. A digital signal is divided into a predetermined number of symbols, and a sync signal, a control signal, and an error detection and correction code are added to each of the digital signals divided into the predetermined number of symbols to form a block format, and a predetermined number of In a digital signal recording apparatus in which a recording area of one track is formed by the block and a plurality of tracks are simultaneously recorded on a magnetic recording medium by a rotary head, at least a first digital signal can be recorded in the recording area of the one track. Na first
Recording area and a second digital signal recordable second
The recording area includes a preamble, a postamble, and a gap between the recording areas, and margins are provided at both ends of one track. The total margin and preamble, the preamble, the gap, and the postamble. And a total of postamble and margin are each an integral multiple of the block length, and a digital signal recording circuit for recording by the rotary head is provided.