JP3025661B2 - Digital signal recording / reproducing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to digital signal recording.
The present invention relates to a reproducing apparatus , and more particularly to a digital signal recording / reproducing apparatus capable of handling both an uncompressed signal and a compressed signal.

[0002]

2. Description of the Related Art Conventionally, for example, a D2 format VTR has been known as a digital signal recording / reproducing apparatus. However, in such a conventional VTR, although it is possible to record an uncompressed signal without data compression, there is no mention of recording a compressed signal or recording the uncompressed signal after data compression.

[0003]

The above-mentioned conventional digital VTR is characterized by high image quality and no dubbing deterioration, but no consideration has been given to data-compressed signals.

An object of the present invention is to provide a digital signal recording / reproducing apparatus capable of recording both an uncompressed signal and a compressed signal on a recording medium in the same format, and to be able to cope with the compressed signal. An object of the present invention is to expand a use range of a recording / reproducing apparatus. For example, by supporting a compressed signal, it is also possible to record a broadcast using a data-compressed signal.

[0005]

The above object is achieved as follows. A mode for recording a compressed input signal on a recording medium
And a mode for recording an uncompressed input signal to the recording medium.
In the digital signal recording and reproducing apparatus having a compressed digital signal input means for inputting a compressed digital signal, an analog uncompressed signal input means for inputting an analog uncompressed signal, the input analog uncompressed signal to a digital non-compressed signal a / D converting means for converting a data compression means for data compressing the same conversion method as the compressed digital signal that is the input of the digital non-compressed signal, the motor
Mode setting means for setting a code, and one of the digital compression signal from the data compression means and the digital compression signal from the digital compression signal input means is set in the mode.
Select according to the mode set by the setting means
Selecting means for correcting an error in the selected digital compressed signal.
Error correction code adding means for adding a positive code;
Recording signal processing means for performing predetermined signal processing on the digital compressed signal from the sign adding means ; recording means for recording the recording signal on a recording medium; reproducing means for reproducing a signal from the recording medium; Reproduction signal processing means for performing predetermined signal processing; and digital pressure from the reproduction signal processing means.
The recording / reproducing is performed using the error correction code included in the compressed signal.
Error correcting means for correcting an error generated in a raw process;
And compressed digital signal output means for outputting the compressed digital signal from the correcting means while being compressed, the compressed digital signal from said error Ri correcting means <br/>, the conversion method in the data compression means data decompression in the opposite manner Data decompression means for converting the digital uncompressed signal into an analog uncompressed signal, and analog uncompressed signal output means for outputting the analog uncompressed signal from the D / A conversion means. During recording, the input digital compressed signal is recorded on a recording medium while the data is compressed. Here, the data compression means compresses data using cosine transform, and the data decompression means performs data decompression using inverse cosine transform, and the input digital compressed signal and analog uncompressed signal are the same. It is preferable that the video signal is of a system type.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIG. In FIG. 1, 1 is an input terminal for a standard analog video signal, 2 is an input terminal for a standard digital video signal, 3 is an input terminal for a high-speed digital video signal, 5 is a recording system mode switch, and 6 is a recording system switching signal generating circuit. ,
10 is an A / D converter, 20 is a switching circuit, 30 is a data compression circuit, 40 is a switching circuit, 50 is the addition of an error correction code,
A recording signal processing circuit for performing signal processing such as recording modulation, 6
0 is a servo control circuit, 70 is a cylinder, 71 is a magnetic tape, 72 and 72 'are magnetic heads, 80 is a reproduction system signal processing circuit for performing signal processing such as reproduction demodulation, error detection and error correction, 90 is a switching circuit, 100 is a data decompression circuit, 120
Is a D / A converter, 131 is an output terminal of a standard analog video signal, 132 is an output terminal of a standard digital video signal, 1
Reference numeral 33 denotes an output terminal for a high-speed digital video signal, 135 denotes a reproduction system mode switch, and 136 denotes a reproduction system switching signal generation circuit.

Next, the operation of the embodiment shown in FIG. 1 will be described below. In the present embodiment, as an example, a description will be given using a digital magnetic recording / reproducing apparatus having a standard speed reproduction mode and a high speed recording mode at the time of recording, and a standard speed reproduction mode and a high speed reproduction mode at the time of reproduction. The recording signal is an NTSC signal as an example, and FIG. 2 shows the specifications of each input video signal. The standard transmission rate shown in FIG. 2 is, for example, a specification in a case where an NTSC signal is sampled by a sampling clock of 4 fsc and quantized by 8 bits.

First, standard speed recording will be described. The standard analog video signal input from the input terminal 1 is A / D
A predetermined sampling clock (4fs
In c), the signal is converted from an analog signal to a digital signal, and is input to the terminal 20a of the switching circuit 20. Where A / D
The transmission rate after the conversion is 114 Mbps. On the other hand, the standard digital video signal (transmission rate 114 Mbps) is input from the input terminal 2 and sent to the terminal 20 b of the switching circuit 20.

Here, the standard digital video signal is a signal obtained by digitally transmitting the above standard analog video signal, and as shown in FIG.
The converted output and the standard digital video signal have the same transmission rate.

When the recording system mode changeover switch 5 is switched according to the input signal, the recording system switching signal generating circuit 6 outputs switching signals RS1 and RS2. Switching circuit 20
Is controlled by the switching signal RS1. When the input signal is a standard analog video signal, the terminals are switched so that the terminals 20a and 20c are connected. When the input signal is a standard digital video signal, the terminals 20b and 20c are connected. Are switched to connect. Digital signal output from terminal 20c of switching circuit 20 (transmission rate 114 Mbps)
Is input to the data compression circuit 30, and is subjected to vector quantization,
Predetermined data compression processing such as Hadamard transform and cosine transform is performed. In the present embodiment, for example, 1 / 11.4
The data compression process is performed twice. Therefore, in the present embodiment, the digital signal is converted into a digital signal having a transmission rate of 10 Mbps by the data compression process, and then input to the terminal 40a of the switching circuit 40. The switching circuit 40 is controlled by a switching signal RS2 output from the recording system switching signal generation circuit 6. When the input signal is a standard analog video signal or a standard digital video signal, the terminals 40a and 40c are connected. The signal is switched and input to the recording signal processing circuit 50. In the recording system signal processing circuit 50, the data compressed signal (10M
After performing signal processing such as channel division, addition of an error correction code, and recording modulation with a predetermined processing clock RCK1 corresponding to bps), the signal is supplied to the magnetic heads 72 and 72 ′ attached to the cylinder 70, The information is recorded on the magnetic tape 71. The cylinder 70 and the magnetic tape 71 are controlled by the servo control circuit 60. Servo control circuit 60
Controls the cylinder motor and the capstan motor in accordance with the switching signal RS2 so as to achieve a predetermined cylinder rotation speed RR1 and a tape speed RT1 and to synchronize with an input video signal.

Next, the case of high-speed recording will be described.
The high-speed digital video signal input from the input terminal 3 is
The signal is sent to the terminal 40b of the switching circuit 40. Here, the high-speed digital video signal is a signal obtained by further compressing the time axis of the digital video signal subjected to the same data compression processing performed by the data compression processing circuit 30 to increase the transmission rate. In this embodiment, as an example, the time axis compression ratio is set to 1/10,
Therefore, the transmission rate of the high-speed digital video signal is 100 Mbps in this embodiment. Since the high-speed digital video signal is a signal that has already been subjected to data compression processing, there is no need to pass through the data compression circuit 30. When the recording mode changeover switch 5 is set to the high-speed digital video signal side, a changeover signal RS2 corresponding thereto is output from the recording system changeover signal generation circuit 6 to control the changeover circuit 40, and the terminals 40b and 4
0c is switched to be connected, and a high-speed digital video signal is input to the recording-system signal processing circuit 50. In the recording signal processing circuit 50, the high-speed digital video signal (1
00Mbps) at a predetermined processing clock RCK2,
For example, after performing signal processing such as channel division, addition of an error correction code, and recording modulation, the signal is supplied to the magnetic heads 72 and 72 ′ attached to the cylinder 70, and the magnetic tape 71.
Record above. The cylinder 70 and the magnetic tape 71 are controlled by the servo control circuit 60. The servo control circuit 60 controls the cylinder motor and the capstan motor so that the predetermined number of cylinder circuits RR2 and the tape speed RT2 are obtained in accordance with the switching signal RS2, and in synchronization with the input video signal.

According to the present invention, the recording signal processing circuit 50,
The servo control circuit 60 enables recording on the tape in exactly the same format for both standard speed recording and speed recording, and enables a significant reduction in recording time in the high-speed recording mode. Basically, the processing clock RCK for standard speed recording
1. Cylinder rotation speed RR1, tape speed RT1, processing clock RCK2 for high-speed recording, cylinder rotation speed RR
2. It is realized by setting the tape speed RT2 in a predetermined relationship according to the recording signal processing format. As an example, RCK1: RCK2, RR1: RR2, RT
By setting the relationship of 1: RT2 to 1:10, 10-times high-speed recording can be performed.

Here, the specific circuit configuration and circuit operation of the recording system signal processing circuit 50 for realizing standard speed recording and high speed recording, the operation of the servo control circuit 60, the number of magnetic heads,
Various methods are conceivable for the mounting method and the like.

Next, signal processing during reproduction will be described. In the present invention, the recording pattern on the magnetic tape is the same whether the recording mode is the standard speed recording or the high speed recording. As a result, regardless of the recording mode, the reproduction can be selected from standard speed reproduction and high speed reproduction.

First, the normal speed reproduction will be described. When standard speed reproduction is selected by the reproduction system mode switch 135, the reproduction system switching signal generation circuit 136 outputs a switching signal PS2 corresponding to the standard speed reproduction. Servo control circuit 6
0 controls the cylinder motor and the capstan motor so that the predetermined cylinder rotation speed RR1 and the tape speed RT1 are obtained according to the switching signal PS2. Magnetic head 7
The signals reproduced by 2, 72 'are input to the reproduction signal processing circuit 80. In the reproduction system signal processing circuit 80,
After performing signal processing such as reproduction demodulation, channel synthesis, error detection, and error correction with a predetermined processing clock RCK1 corresponding to standard speed reproduction, a reproduction signal (10 Mbps) is supplied to a terminal 90a of the switching circuit 90. The switching circuit 90 is controlled by the switching signal PS2, and is switched so that the terminal 90a and the terminal 90c are connected during normal speed reproduction.
The reproduction signal is sent to the data decompression circuit 100. The data decompression circuit 100 restores the original signal by performing signal processing reverse to data compression processing at the time of recording. The data decompression rate at this time is the opposite of the data compression rate, and is set to 11.4 times in this embodiment. Therefore, the transmission rate returns to the original one (114 Mbps in this embodiment). The reproduced signal subjected to the data expansion processing is sent to the D / A converter 120 and the output terminal 132. After the signal input to the D / A converter 120 is converted from a digital signal to an analog signal, the output terminal 1
31 outputs a standard analog video signal. On the other hand, the output terminal 132 outputs a standard digital video signal output.

Next, high-speed reproduction will be described. When high-speed playback is selected by the playback system mode switch 135,
A switching signal PS2 corresponding to high-speed playback is output from the playback system switching signal generation circuit 136. The servo control circuit 60
According to the switching signal PS2, a predetermined cylinder rotational speed RR
2. Cylinder motor so that tape speed RT2
Controls the capstan motor. Magnetic head 72,
The signal reproduced by 72 ′ is input to the reproduction-system signal processing circuit 80. The reproduction system signal processing circuit 80 performs signal processing such as reproduction demodulation, channel synthesis, error detection, and error correction with a predetermined processing clock RCK2 corresponding to high-speed reproduction, and then outputs a reproduction signal ( 1
00 Mbps). The switching circuit 90 is controlled by the switching signal PS2, and is switched so that the terminals 90a and 90b are connected during high-speed reproduction, and a high-speed digital video signal is output from the output terminal 133.

According to the present invention, standard speed reproduction and high speed reproduction can be performed by the servo control circuit 60 and the reproduction system signal processing circuit 80, and the reproduction time can be greatly reduced in the high speed reproduction mode. Basically, the processing clock R at the time of standard reproduction
CK1, cylinder rotation speed RR1, tape speed RT1
And a predetermined relationship between the processing clock RCK2 during high-speed reproduction, the cylinder rotation speed RR2, and the tape speed RT2. As an example, RCK1: RCK
2, RR1: RR2, RT1: RT2: 1:10
By doing so, 10 times high-speed reproduction is possible.

Here, the specific circuit configuration and circuit operation of the reproduction system signal processing circuit 80 for realizing standard speed reproduction and high speed reproduction, the operation of the servo control circuit 60, the number of magnetic heads,
Various methods are conceivable for the mounting method and the like.

Next, a second embodiment will be described with reference to FIG. The second embodiment has almost the same components as the first embodiment, but the position of the switching circuit 40 is different.
Disappears, and the number of switching circuits 45 is newly increased.

First, standard speed recording and reproduction will be described. During normal speed recording, the switching circuit 45 switches so that the terminals 45a and 45c are connected, and the switching circuit 40 switches so that the terminals 40a and 40c are connected. The other circuit operations are exactly the same as the circuit operations of the first embodiment, and the description is omitted. At the time of normal speed reproduction, the operation is completely the same as that of the first embodiment except that the switching circuit 90 is eliminated, and the description is omitted.

On the other hand, high-speed recording and high-speed reproduction are different in that transmission of high-speed digital video signals is performed in a recording format. That is, the input / output high-speed digital video signal is transmitted after being subjected to signal processing such as addition and modulation of an error correction code performed by the recording signal processing circuit 50. Therefore, at the time of high-speed recording, the data is directly recorded on the tape via the switching circuit 40 without passing through the recording-system signal processing circuit 50. At the time of high-speed reproduction, the reproduced signal is subjected to reproduction signal processing such as error detection and error correction by the reproduction system signal processing circuit 80, and then input to the terminal 45 b of the switching circuit 45. The switching circuit 45 is controlled by PS2 output from the reproduction system switching signal generation circuit 136. During high-speed reproduction, the switching circuit 45 switches so that the terminals 45b and 45c of the switching circuit 45 are connected, and the reproduction signal is a recording system signal. The data is sent to the processing circuit 50. After the recording signal processing circuit 50 performs recording signal processing such as addition of an error correction code and recording modulation to form a recording format, the output terminal 133 outputs a high-speed digital video signal.

In the examples described above, both high-speed recording and high-speed reproduction have been described as examples of 10-times speed. However, the present invention is not limited to 10-times speed, and the same applies to arbitrary n-times speed recording and reproduction. And can be applied.

In this embodiment, an example is described in which all modes of standard speed recording, high speed recording, standard speed reproduction, and high speed reproduction are combined. However, it is not always necessary to provide all modes. There may be an example that has only one.

Next, an example of the circuit configuration, circuit operation, tape speed, and the like of the recording system signal processing circuit 50, the servo control circuit 60, and the reproduction system signal processing circuit 80 after the data compression process of FIG. 1 will be described with reference to FIGS. 6 will be described in detail.

In FIG. 4, reference numeral 201 denotes a synchronization detection circuit;
04 is a recording modulation circuit, 205 is a cylinder servo control circuit, 206 is a capstan servo (tape speed) control circuit, 207 is a reproduction reference signal generation circuit, 210 is a demodulation circuit, 211 is a cylinder, 212 is a pair of recording heads, 2
13 is a pair of reproducing heads, 214 is a capstan for controlling the tape speed, 215 is a magnetic tape, 216 is a sending reel, and 217 is a take-up reel. FIG. 5 is a diagram showing the timing of the input / output signals of the present embodiment.
51 is a compressed image signal which is an input signal, 252 is 2
Reference numerals 51 and 255 denote standard speed reproduction signals, which are output signals, and reference numeral 256 denotes a reproduction synchronization signal.

The present embodiment is an example in which the tape speed during recording and the number of cylinder rotations are each set to n times the speed at the standard speed reproduction, thereby realizing n-times speed recording. As shown in FIG. 5, a compressed video signal and a synchronizing signal which are input signals of this circuit are
At the time of reproducing one screen at the standard speed (16.7 ms in the case of the NTSC signal), it is composed of information 251 of n screens and n synchronization pulses 252 synchronized therewith. Sync pulse 252
Is separated from the compressed video signal by the synchronization detection circuit 201 in FIG. 4, but if there is a compression circuit in the preceding stage, the control signal in the preceding stage may be used. This image information is converted into a predetermined recording format by the recording modulation circuit 204 and recorded on the magnetic tape 215 by the recording head 212. At this time, the synchronizing signals of the cylinder servo control circuit 205 and the capstan servo control circuit 206 are changed as shown in FIG.
1, the number of rotations of the cylinder 211 and the feed speed of the magnetic tape 215 are increased by n times according to the n-times speed video signal, so that the format is the same as that of the normal speed recording. It becomes possible to record. At the time of reproduction, a synchronization signal of the cylinder servo control circuit 205 and the capstan servo control circuit 206 is supplied from the reproduction reference signal generation circuit 207, the cylinder speed and the tape speed are returned to the normal speed, and the signal read from the reproduction head 213 is read. The signal is demodulated by the demodulation circuit 210 and output. Also, in this circuit, the input video signal and synchronization signal are transmitted at normal speed, that is, n
By setting it to 1 × speed, normal speed recording is possible as it is. Further, by making the frequency of the output signal from the reproduction reference signal generator n times, it is possible to perform n times speed reproduction.

Another embodiment will be described with reference to FIG. 6, reference numeral 201 denotes a synchronization detection circuit, 202 denotes a synchronization signal dividing circuit, 203 denotes a memory for temporarily storing information,
204 is a recording modulation circuit, 205 is a cylinder servo control circuit, 206 is a capstan servo (tape speed) control circuit, 207 is a reproduction reference signal generation circuit, 208 reproduction reference signal frequency dividing circuit, and 209 is a memory for temporarily recording a reproduction signal. ,
210 is a demodulation circuit, 211 is a cylinder, 212 is an m pair of recording heads, 213 is an m pair of reproducing heads, 214 is a capstan for controlling the tape speed, 215 is a magnetic tape,
216 is a delivery reel, and 217 is a take-up reel.

FIG. 7 is a diagram showing the timing of the input / output signals of this embodiment. Reference numeral 251 denotes a compressed image signal as an input signal; 252, a sync signal of 251;
4 is a diagram schematically showing an output signal of the recording signal temporary storage memory 203, reference numeral 254 is a synchronizing signal divided by m, reference numeral 255 is a standard speed reproduction signal which is an output signal, and reference numeral 256 is a reproduction synchronizing signal.

This embodiment is an example in which magnetic signals of m screens are simultaneously recorded on m tracks using m pairs of heads, and high-speed recording is realized while suppressing an increase in the number of cylinder rotations. For playback, m pairs of playback heads are used. This figure shows a case where two screens of information are simultaneously recorded on two tracks by using two pairs of heads. However, a case where three or more pairs of heads are used is also possible. As shown in FIG. 7, the compressed video signal and the synchronizing signal which are the input signals of this circuit are used to reproduce one screen at a standard speed (one time for an NTSC signal).
6.7 ms), and information 251 of an n × m screen and (n × m) synchronization pulses 252 generated thereby.
The video signal time-compressed by (n × m) times is temporarily stored in each address of the memory 203 having a storage capacity of m screens, and from there, information of each screen is displayed as shown in FIGS. Is converted into a parallel signal every time, and is sent to the recording modulation circuit 204 in parallel. The recording signal output from the recording modulation circuit 204 is input in parallel to the m recording heads 212 and is recorded on the magnetic tape 215. At this time, the recording speed per head is n times the normal speed. Therefore, the m-divided reference signal (FIG. 7-254) is input to the cylinder servo control circuit 205. On the other hand, in order to write n × m tracks in one screen time, it is necessary to advance the tape at a speed n × m times that of normal speed recording. Therefore, the capstan control circuit 206 includes n ×
An m-times reference signal (FIG. 7-252) is input. At this time, since the inclination of the recording head trajectory on the tape changes depending on the ratio between the tape speed and the cylinder speed, the inclination between the tape and the cylinder differs from that in the embodiment of FIG.
It is necessary to design according to. With such a design, recording is performed on the tape in exactly the same format as when recording at normal speed. During reproduction, the cylinder servo control circuit 205 and the capstan servo control circuit 206
Are supplied from the reproduction reference signal generation circuit 207,
The cylinder speed and the tape speed are returned to the normal speed, and the signals read in parallel from the reproducing head 213 are demodulated by the demodulation circuit 210.
Demodulates with and outputs. However, in this embodiment, since the reading is performed simultaneously by m heads, the cylinder rotation speed is
In this case, the speed is 1 / m times as fast. Further, in this embodiment, it is possible to simplify the reproducing circuit by using a pair of reproducing heads. However, in this case, since only one track is reproduced at a time, the cylinder rotation speed is set to n in the above embodiment.
Need to double. In this case, since the inclination of the trajectory of the reproducing head on the tape depends on the number of rotations of the cylinder, it is necessary to adjust the tracking by using a movable head as the reproducing head.

[0030]

As described above, according to the present invention,
Digit that can record and play back uncompressed and compressed signals
This makes it possible to realize a digital signal recording / reproducing apparatus, and has an effect that, for example, it becomes possible to record a broadcast using a data-compressed signal.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of the present invention.

FIG. 2 is a diagram showing specifications of a recording signal.

FIG. 3 is a block diagram showing a second embodiment.

FIG. 4 is a block diagram for explaining in detail a circuit configuration of the embodiment shown in FIG. 1;

FIG. 5 is a signal waveform diagram for explaining an operation of the embodiment shown in FIG. 4;

FIG. 6 is another block diagram showing a circuit configuration of the embodiment shown in FIG. 1;

FIG. 7 is a signal waveform diagram for explaining the operation of the embodiment shown in FIG. 6;

[Explanation of symbols]

 1, 2, 3, ... input terminal, 10 ... A / D converter, 30 ... data compression circuit, 50 ... recording system signal processing circuit, 60 ... servo control circuit, 80 ... reproduction system signal processing circuit, 100 ... data expansion Circuits: 120: A / D converter; 131, 132, 133: Output terminals.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Keizo Nishimura 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Inside the Home Appliance Research Laboratory, Hitachi, Ltd. (72) Inventor Yuzumi Watani 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Inside Hitachi, Ltd., Home Appliance Research Laboratory (72) Inventor Akira Shibata 292, Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Inside Hitachi, Ltd. Home Appliance Research Laboratory (56) References JP-A-64-73560 (JP, A) JP-A-3-242877 (JP, A) JP-A-1-240088 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04N 5/91-5/956 H04N ^7/ 24- 7/68 H04N 5/782-5/783

Claims (4)

(57) [Claims] 1. A mode for recording a compressed input signal on a recording medium
And a mode for recording an uncompressed input signal on the recording medium.
A digital compressed signal input means for inputting a digital compressed signal, an analog non-compressed signal input means for inputting an analog uncompressed signal, and an analog non-compressed signal input to the analog non-compressed signal input means. A / D conversion means for converting a signal into a digital uncompressed signal, and a digital compression means for compressing the digital uncompressed signal from the A / D conversion means in the same manner as the digital compression signal inputted to the digital compression signal input means. and data compression means for, a mode setting means for setting the mode, one of the compressed digital signal from the compressed digital signal and the previous SL compressed digital signal input means from the data compression means is set by said mode setting means Said
Accordance chromatography de, selection means for selecting an error correction to the compressed digital signal selected by said selection means
Error correction code adding means for adding a code, recording signal processing means for performing predetermined signal processing on the digital compressed signal from the error correction code adding means , and recording the recording signal from the recording signal processing means on a recording medium Recording means; reproducing means for reproducing a signal recorded on the recording medium; reproducing signal processing means for performing predetermined signal processing on the reproduced signal from the reproducing means; and a digital compression signal from the reproduced signal processing means. Included
Generated in the recording / reproducing process using the error correcting code.
And error correcting means for correcting errors, and the compressed digital signal output means for outputting remain compressed digital compressed signal from said error correction means, the compressed digital signal from said error correction means, conversion method in the data compression means Data decompression means for decompressing data in a manner reverse to the above, D / A conversion means for converting a digital uncompressed signal from the data decompression means into an analog uncompressed signal, and an analog uncompressed signal from the D / A conversion means And an analog non-compressed signal output means for outputting the compressed digital signal. At the time of recording, the inputted digital compressed signal is recorded on a recording medium while data compression is performed. 2. The digital signal recording / reproducing apparatus according to claim 1, wherein said data compression means compresses data using cosine transform, and said data decompression means performs data decompression using inverse cosine transform. Digital signal recording and reproducing device. 3. The digital signal recording / reproducing apparatus according to claim 1, wherein the input digital compressed signal and the analog uncompressed signal are video signals of the same system. . 4. A digital signal recording / reproducing apparatus according to claim 3, wherein said video signal of the same system is an NTSC video signal.