JPH11234621A - Digital recording and playback device - Google Patents

Abstract

(57) [Problem] To provide a digital recording / reproducing apparatus which can switch recording quality according to the type of signal in digital recording, is easy to use, and considers the economics of a recording medium. Reproducing a medium on which analog signals are recorded. A digital recording / reproducing apparatus for compressing and decompressing a video signal and an audio signal, and recording and reproducing the compressed digital data on a magnetic tape, wherein the compression and decompression means sets a compression rate. A means for changing to an arbitrary value or a means for setting to a predetermined fixed rate is provided. Further, a conventional means for reproducing a magnetic tape on which analog recording is performed is provided, and means for digitizing and outputting the analog reproduction signal is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
A digital recording / reproducing device that not only records and reproduces audio signals, but also digitizes analog video and audio signals and records them on recording media, and also reproduces digital signals from recording media and restores the original analog video and audio signals. About.

[0002]

2. Description of the Related Art In a home digital recording / reproducing apparatus, for example, a digital VTR, a video signal and an audio signal are replaced with digital signals and recorded, thereby obtaining a high-quality video. At that time, reduce the tape consumption,
In order to enable long-time recording, video and audio signals are digitized, and the amount of recorded data is reduced by high-efficiency encoding (data compression). For example, in a home digital VTR currently commercialized, the information amount of a video signal is compressed to about one fifth (about 25 Mbps) and recorded on a magnetic tape.

An example of recording a video signal and an audio signal as compressed digital information on a magnetic tape or a magneto-optical disk as described above is disclosed in JP-A-8-9330.

[0004]

However, the compression means used in the above-mentioned home digital VTR has a constant compression rate (for example, 25 Mbp).
s). Therefore, the recording time is constant, and only 2 hours can be recorded per one roll of the dedicated magnetic tape. Also, when receiving and recording a television signal, recording is always performed at the same compression rate irrespective of the type of program, which is wasteful. As described above, the conventional digital VTR is insufficient in consideration of the economy of tape consumption and the usability of the user.

An object of the present invention is to provide a user-friendly recording / reproducing apparatus capable of recording and reproducing video signals and audio signals on a recording medium at an arbitrary compression rate.

[0006]

In order to achieve the above object, according to the present invention, there is provided a compression generating means for performing a compression process on a digital video signal and a digital audio signal to obtain compressed data;
Expansion generating means for performing expansion processing on the compressed data to obtain original digital video signals and digital audio signals, recording means for recording the compressed data on a recording medium, and reproducing means for reproducing the compressed data from the recording medium; When the input video signal and audio signal are analog signals, the digital video signal and digital audio signal are converted into digital signals by analog-digital conversion means, and the converted digital video signals and digital audio signals are sent to the compression generation means. If the video and audio signals to be input are already compressed digital signals,
The input signal is directly recorded on the recording medium.

Further, according to the present invention, analog signal reproducing means for reproducing a recording medium on which an analog video signal and an analog audio signal are recorded, and the reproduced analog video signal and analog audio signal are converted by an analog-to-digital conversion means. It is characterized by comprising a means for converting the digital data into a digital signal and sending it to the compression generation means, and a digital output means for outputting the compressed data from the compression generation means to the outside.

In the present invention, the compression generation means includes a compression rate setting means capable of setting an arbitrary compression rate, the compression rate setting means including a compression rate fixing means for setting a fixed compression rate, Compression rate changing means for adaptively changing a compression rate according to a video signal and an audio signal to be transmitted.

With the above configuration, the compression rate can be appropriately changed according to the quality of a television program or an input video signal and audio signal, and long-time recording can be realized while suppressing tape consumption.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Processing of a video signal and an audio signal in each embodiment of the present invention will be described in detail with reference to the drawings.

(First Embodiment) FIG. 1 is a block diagram showing a configuration of a digital recording / reproducing apparatus according to a first embodiment. First, the input side will be described below.
The analog video signal is input from the video input terminal 2, transmitted to the video analog-to-digital converter (hereinafter referred to as video ADC) 9 via the switch circuit 6, and converted into a digital video signal. The digital video signal is converted by the video decoder 11 into ITU-R BT. 601 (International Telecommunication Union Wireless Communication Center) -compliant digital data, and a video data compression device such as MPEG2 (Mov
ing Picture Experts Group
In 2), it is encoded with high efficiency, and is sent to the video / audio digital interface 14 as digital video compression data.

On the other hand, an analog audio signal is input from an audio input terminal 4 and sent to an analog-to-digital converter for audio (hereinafter referred to as audio ADC) 10 via a switch circuit 7 to be converted into a digital audio signal. The digital audio signal is encoded with high efficiency by, for example, MPEG2, and is sent to the video / audio digital interface 14 as audio digital compressed data.

Next, the case where the analog video signal and the audio signal to be inputted from the television analog receiver 8 will be described. A television broadcast wave is received from the antenna 1, separated into a video signal and an audio signal by the analog receiver 8, and transmitted to the switch circuits 6 and 7, respectively. The switch circuits 6 and 7 selectively switch whether the source is the analog receiver 8 or the external input terminal (the video input terminal 2 and the audio input terminal 4) according to the signal from the source switching input terminal 5.

If the input signal is a digital signal that has already been compressed (video and audio are input in the same system in a time-division manner), it is input from the digital input terminal 3 and directly to the video / audio digital interface 14. Sent out.

Next, the recording apparatus and the recording operation will be described. In the first embodiment, the VTR device 17 uses a magnetic tape (for example, VHS tape, 8 mm tape, 6 mm tape) as a recording medium. The VTR device 17 is a conventional helical scan type VTR device, in which a magnetic tape is wound around a rotating drum, and a magnetic head mounted on the rotating drum performs recording and reproduction on the magnetic tape obliquely.

The compressed video data and audio data are subjected to error correction code redundancy in the video / audio digital interface 14 and to system information (recording date / time, time code, program name, etc.) other than video / audio data. ) Are multiplexed and sent to the recording signal processor 15 as a digital signal of one system. In the recording signal processing 15, the signal is modulated into a recording signal suitable for a magnetic tape, sent to the VTR device 17, and recorded on the magnetic tape.

Next, the reproducing operation will be described. The digital reproduction signal reproduced from the magnetic tape by the VTR device 17 is demodulated to the original digital multiplexed data by the reproduction signal processing 16, and the video / audio digital interface 1 is reproduced.
4 is sent. The digital multiplexed data is subjected to error correction processing in the video / audio digital interface 14, and is restored into compressed video data, compressed audio data, and system information.

The compressed video data is transmitted from the video / audio digital interface 14 to the video data decompression device 2.
Sent to 0. In the video data decompression device 20, the ITU-R BT. 601
The video data is decompressed into digital video data conforming to (International Telecommunication Union Wireless Communication Center) and transmitted to the video encoder 21. The video encoder 21 converts the digital video signal into a digital video signal, and the digital-to-analog converter for video (hereinafter, video DAC) 22 converts the digital video signal into an analog video signal and outputs the analog video signal to a video output terminal 24.

On the other hand, the compressed audio data is sent from the video / audio digital interface 14 to the audio data decompression device 18, where it is subjected to, for example, MPEG2 decompression processing, and is converted into digital audio data that has undergone time-base expansion. . Further, the audio signal is sent to a digital-to-analog converter for audio (hereinafter, audio DAC) 19, converted into an analog audio signal, and output to an audio output terminal 23.

As described above, in the first embodiment, the MP
By providing a compression device of EG2 and a decompression device of MPEG2, an analog video signal and an audio signal from the outside or an analog video signal and an audio signal from a television receiver are MPEG2 encoded and recorded / reproduced on a magnetic tape. I made it. When the input signal is a digital signal which has already been MPEG2 compressed, the input signal is directly recorded on a magnetic tape as it is. Thus, it is possible to provide a digital recording / reproducing apparatus whose input corresponds to both a digital signal and an analog signal. In the first embodiment, MPEG2 is described as an example of the compression and decompression device, but the same operation can be performed by using other compression means.

(Second Embodiment) Next, a digital recording / reproducing apparatus according to a second embodiment of the present invention will be described. FIG. 2 is a block diagram showing the configuration of the digital recording / reproducing apparatus according to the present embodiment. The same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

In FIG. 2, reference numeral 31 denotes an analog audio reproducing process, 32 denotes an analog video reproducing process, and 30 denotes a digital signal output terminal. The VTR device 17 is a magnetic tape (for example, a conventional VHS video tape, an 8 mm video tape, or the like) on which analog video signals and audio signals are analog-recorded.
It has a function to play back. Then, it automatically determines whether the signal reproduced from the magnetic tape is analog recording or digital recording.

In the case of analog recording, an analog video reproduction signal is transmitted to an analog video reproduction process 32, and an analog audio reproduction signal is transmitted to an analog audio reproduction process 31. The analog video signal output from the analog video reproduction processing 32 is transmitted to the switch circuit 6, becomes digital compressed video data via the video ADC 9, the video decoder 11, and the video data compression device 12, and is transmitted to the video / audio digital interface 14. Is done. The analog audio signal output from the analog audio reproduction processing 31 is sent to the switch circuit 7 and becomes digital compressed audio data via the audio ADC 10 and the audio data compression device 13.
It is sent to the audio digital interface 14. From the video / audio digital interface 14, digital compressed data obtained by multiplexing video, audio, and system information is output to the digital signal output terminal 30.

When the reproduced signal is digitally recorded,
This is the same as in the first embodiment. The switch circuits 6 and 7 operate to switch between analog audio reproduction processing and analog video reproduction processing in the case of reproducing an analog-recorded magnetic tape.

With the above configuration, a conventional analog-recorded magnetic tape (VHS video tape, 8 m
m video tape). In addition, the reproduced video and audio signals can not only be output to the outside as analog signals, but also can be converted to time-axis-compressed digital data and output to the outside. The compressed digital signal output to the outside can be digitally dubbed in a digital recording / reproducing apparatus having the same interface, and can be dubbed without any deterioration in image quality and with easy operation. In recent years, the performance of a personal computer (hereinafter referred to as a personal computer) has been greatly improved with the improvement in the performance of a microprocessor and the increase in the capacity of a memory and a hard disk, and video data can be easily handled.
As a result, the personal computer and the digital recording / reproducing apparatus are connected via the digital signal output terminal 30, and the sharing of the compressed video / audio digital data can be realized. Also, in the process of digital compression / expansion processing of analog-recorded magnetic tape, reduction of analog noise, updating of video color, etc. can be easily performed by digital signal processing, thereby improving image quality. it can. In addition, there is a great effect that signal processing of the reproduction system can be shared between digital recording and analog recording.

In the above embodiment, a magnetic tape is used as a recording medium. However, the present invention is not limited to this. For example, a magneto-optical disk, an optical disk, a semiconductor memory, or a hard disk may be used.

(Third Embodiment) Next, a digital recording / reproducing apparatus according to a third embodiment of the present invention will be described. FIG. 3 shows an internal block diagram of the video compression processing 12 according to the third embodiment. 3, reference numeral 50 denotes a terminal to which uncompressed video digital data is input, 51 denotes a control input terminal for setting a compression rate, 52 denotes an output terminal of compressed video digital data, and 53 denotes an information encoder for performing data compression processing. , 54 are data format generators 1 for performing a variable-length data format after compression, 55 is an output buffer for storing compressed video data and outputting the compressed video data when a predetermined value is reached, 56 is a code amount allocation Controller for setting quantization parameters and quantization parameters, 57
Is a compression rate setting device, 58 is a data format generator 2 for performing a fixed-length data format after compression, and 59 is a switch circuit.

Hereinafter, the data compression method will be described by using the MPEG method, but the present invention is not limited to this compression method. Before describing the block diagram operation, information compression of video will be described. For example, in the MPEG compression method, information (I picture) obtained by intra-coding video data, information (P picture) obtained by inter-frame prediction based on prediction from the past, and inter-frame coding obtained by prediction from the past and the future are used. One unit consisting of a predetermined number of images each of I picture, P picture, and B picture is composed of three pieces of information (B picture).
Picture). The above I picture, P picture and B picture are generated using the following three compression means.

(1) Information compression using spatial correlation, (2) Information compression using temporal correlation, (3)
Information compression utilizing the bias of code appearance establishment when encoding by the above two compression methods.

First, (1) information compression based on spatial correlation means that one image is divided into predetermined pixel blocks, and each block is subjected to DCT (Discrete Cosine).
eTransform: Discrete Cosine Transform)
Decompose one image into frequency components. After DCT conversion, DC
The T coefficient is divided by a predetermined value, and the remainder is rounded and quantized.
The higher the divisor is, the higher the compression ratio can be, but the higher the divisor, the higher the frequency component of the video information is deleted, and the lower the video quality. That is, if the divisor is constant, the compression ratio is constant (compression rate fixed), and the divisor is adaptively changed (compression rate variable) according to the pixel information to improve the quality of pixels. it can.

Next, (2) compression based on temporal correlation means that picture information before and after a video is very similar in most cases, and video transmission is performed by using only a change (movement vector) of the picture as information. The amount of information can be significantly reduced.

Finally, (3) information compression based on the bias of the code appearance rate is performed by assigning a short code length to a value having a high appearance rate for the DCT coefficient or the motion vector, and assigning a long code length to a value having a low appearance rate. , And as a result, the average information amount can be reduced. This operation is called variable length coding.

The above video compression processing is performed by the video data compression device 12 shown in FIG. The digitized video data input from the terminal 50 is sent to the information encoder 53. The information encoder 53 performs a DCT operation for compressing the amount of information.
Performs transformation, quantization, and motion vector extraction. The compression-encoded data is sent to 54 of the data format generator 1. The data format generator 54 performs the information compression based on the bias of the appearance rate of the compressed code described above.
Therefore, compressed data having a different code length (variable length code) due to a difference in picture is sent to the switch circuit 59.
The compressed data is output from the terminal 52 via the output buffer 55. A trigger signal is sent to the encoding controller 56 for each capacity of the output buffer 55, and the encoding timing is controlled. The encoding controller 56 determines the I picture, P
The information encoder 53 assigns a code amount to each picture of a picture and a B picture and sets a quantization parameter.
And a control signal to the data format generator 54. As a result, the amount of compressed data per unit time (hereinafter referred to as data rate) output from the terminal 52 is, for example, an average data rate of 6 Mbps, and changes adaptively from a maximum of 12 Mbps to a minimum of 4 Mbps depending on the picture of the video source.

On the other hand, there is a fixed length coding means for variable length coding. The fixed length coding means that the data rate is 6
Mbps, 6 Mbps regardless of the picture source picture
This is a means of encoding in ps, and is characterized by the fact that the image quality of a picture with particularly sharp movements tends to be lower than the former variable-length encoding. However, when the recording medium is a sequential magnetic tape, on the contrary, a fixed recording rate is determined by the format, and fixed-length encoding may be more convenient. 58 of the data format generator 2
Receives compression-encoded data from the information encoder 53, always performs fixed-length encoding, and sends out the compressed data to the switch circuit 59.

Next, compression rate setting information is input from a terminal 51. For example, compression rate value information is input according to digital information or the like selected by a user or included in a vertical blanking period of a video signal. As for the compression rate value information, parameter setting information is transmitted to the encoding controller 56 by the compression rate setting unit 57. The encoding controller 56 assigns a code amount to each of the I picture, P picture, and B picture and sets a quantization parameter, and sets the data compression rate of the information encoder 53 and the data format generator 58 to 58. decide. Although the compression rate setting process of the video data compression device 12 has been described above, it is needless to say that the compression rate can be similarly set in the audio data compression device 13.

As described above, according to the third embodiment, the video data compression device 12 and the audio data compression device 13
It has two variable length compression means by variable length coding and two fixed length compression means by fixed length coding. The compression rate (average compression rate in the case of variable length coding) can be set arbitrarily according to the user or the system information. There is a feature that can be set to. Furthermore, the data format generator 58 for performing the variable-length coding can set up to the upper limit compression rate at the time of the variable-length coding. Is big.

(Fourth Embodiment) Next, a digital recording / reproducing apparatus according to a fourth embodiment of the present invention will be described.
This will be described with reference to FIG. For example, at a predetermined compression rate, a solution is provided in a case where the recording capacity of a recording medium (here, a magnetic tape) is insufficient for the recording capacity. A specific example will be described with reference to FIG. In FIG. 6, the horizontal axis indicates the time of a reserved program scheduled to be recorded in percentage, and the vertical axis indicates the remaining recording capacity of a recording medium (here, a magnetic tape) in percentage. 25% of the magnetic tape was already used (that is, the remaining amount was 7%).
Data compression rate 14M using magnetic tape (5%)
When a reserved recording program is recorded in bps, the program is 7
Only up to 5% can be recorded (see FIG. 6). For example, at a point where 50% has been recorded (first monitoring), it is determined from the current compression rate value, the remaining recording capacity of the magnetic tape, and the remaining time of the reserved program whether or not all the programs to be recorded can be recorded. I do. If recording is not possible, the compression rate value is reduced (for example, 7 Mbps) and the tape speed is reduced or automatically operated so as to perform intermittent running in which stop and normal running are repeated, so that all the reserved programs can be recorded. I made it. A plurality of the first monitors may be provided.
FIG. 7 is obtained by adding a tape speed (double speed) curve to FIG. Here, the tape speed is changed to half of the tape speed from the first monitoring point, but intermittent running of stop and normal running may be performed.

The above operation will be described below with reference to the block diagram of FIG. The same parts as those in the third embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted. In FIG. 4, reference numeral 60 denotes an arithmetic unit which determines whether or not all the programs to be recorded are recordable from the remaining capacity value of the recording medium, the remaining time to be recorded, and the current compression rate information. If it is determined that recording is not possible, the function block calculates an appropriate compression rate value and outputs the compression rate value. Reference numeral 61 denotes a recording medium remaining amount detector, which detects the remaining amount of the magnetic tape, converts the remaining amount to a remaining storage capacity, and outputs the result. Reference numeral 62 denotes a program absence recording controller, for example, the first
The television signal receiver described in the embodiment is set to the absence recording setting, and the program is recorded so that the program for the set time is recorded.
The operation of the TR device 17 is controlled. 63 is a tape running setting device, and 64 is a tape speed controller.

The remaining amount of the magnetic tape is detected by the recording medium remaining amount detector 61, converted into a remaining recording capacity value, and sent to the arithmetic unit 60. The absence recording controller 62 sets the absence recording of the television signal receiver and sends the scheduled recording time information to the arithmetic unit 60. The arithmetic unit 60 determines whether or not all the programs to be recorded can be recorded, based on the remaining capacity information of the recording medium, the remaining time information to be recorded, and the current compression rate information. If it is determined that recording is impossible, an appropriate compression rate value (current compression rate or less) is calculated, and the calculated compression rate value is sent to the compression rate setting unit 57. Further, the computing unit 60 calculates a tape speed according to the changed compression rate, and sends the tape speed information to the tape speed setting unit 63. The tape speed setter 63 sends control parameters to the tape speed controller 64 according to the tape speed information, and the tape speed controller 64
As a result, the VTR device 17 changes or stops the tape speed, and performs intermittent drive in normal running.

According to the fourth embodiment, the data compression rate value is changed according to the remaining capacity of the recording medium, the time information of the recording reservation program, and the current compression rate information, and the interruption of the reservation program is interrupted. The effect of preventing recording is significant.

In a magneto-optical disk recording device, an optical recording device, a hard disk device, or a semiconductor memory recording device, the recording medium may be the fourth type.
The means of the embodiment can be used. FIG. 5 shows a case where the magneto-optical disk is a recording medium. However, unlike magnetic tapes, these recording media are suitable for random access and variable rate recording.
It is not necessary to change the rotation speed of the recording medium, and the fourth embodiment can be realized by an intermittent operation of recording or reproduction.

The description of each of the above embodiments is for describing the present invention, and should not be construed as limiting the scope of the claims or reducing the scope of the claims.

Further, the configuration of each part of the present invention is not limited to the above-described embodiment, and it is needless to say that various modifications can be made within the technical scope described in the claims.

[0044]

As described above, the digital recording / reproducing apparatus of the present invention encodes analog video and audio signals or analog video and audio signals from a television receiver into MPEG2 codes and records or encodes them on a magnetic tape. Can be played. In addition, a digital signal which has already been MPEG2 compressed is directly recorded on a magnetic tape as it is, so that a digital recording / reproducing apparatus whose input corresponds to both a digital signal and an analog signal can be provided.

Further, a conventional analog-recorded magnetic tape (VHS video tape, 8 mm video tape) can be reproduced, and the reproduced video and audio signals are converted into time-axis-compressed digital data. Can be output to The compressed digital signal output to the outside can be digitally dubbed by a digital recording / reproducing apparatus having the same interface, so that the image quality does not deteriorate during dubbing and the dubbing operation can be facilitated.

The digital recording / reproducing apparatus has two compression rate changing means and two compression rate fixing means. The compression rate (the average compression rate in the case of the variable compression rate means) is determined by the user or the system information. It can be set arbitrarily and the compression operation can be performed more efficiently by the video source.

Further, the effect of changing the data compression rate value in accordance with the remaining capacity of the recording medium and the time information of the recording reservation program and preventing the recording of the reservation program from being interrupted is significant.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a digital recording / reproducing apparatus according to a first embodiment of the present invention.

FIG. 2 is a block diagram illustrating a configuration of a digital recording / reproducing apparatus according to a second embodiment of the present invention.

FIG. 3 is a block diagram illustrating a configuration of a digital recording / reproducing apparatus according to a third embodiment of the present invention.

FIG. 4 is a block diagram illustrating a configuration of a digital recording / reproducing apparatus according to a fourth embodiment of the present invention.

FIG. 5 is a block diagram showing a configuration in which a recording medium according to a fourth embodiment of the present invention is a magneto-optical disk device.

FIG. 6 is a graph for explaining the operation of the fourth embodiment of the present invention.

FIG. 7 is a graph for explaining an operation of the fourth exemplary embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 receiving antenna 2 video input terminal 3 digital input terminal 4 audio input terminal 5 source switching input terminal 6, 7 switch circuit 8 analog receiver 9 video analog-digital converter 10 audio analog-digital converter 11 video decoder 12 video data compression Device 13 Audio data compression device 14 Video / audio digital interface 15 Record signal processing 16 Reproduction signal processing 17 VTR device 18 Audio data decompression device 19 Audio digital-analog converter 20 Video data decompression device 21 Video encoder 22 Video digital-analog converter Reference Signs List 23 audio output terminal 24 video output terminal 30 digital data output terminal 31 analog audio reproduction processing 32 analog video reproduction processing 53 information encoder 54 data format generator 1 55 output buffer 56 coding controller 57 compression ratios setter 58 data format generator 2 60 calculator 61 recording medium remaining amount detector 62 program automatic answering recording controller 63 tape speed setter 64 the tape speed controller

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Eiji Moro Inventor 1410 Inada, Hitachinaka-shi, Ibaraki Pref. Hitachi, Ltd.

Claims (8)

[Claims] 1. A compression generation means for performing compression processing on a digital video signal and a digital audio signal to obtain compressed data, and a decompression generation means for performing expansion processing on the compressed data to obtain original digital video signals and digital audio signals. Recording means for recording the compressed data on a recording medium,
A digital recording / reproducing apparatus comprising: reproducing means for reproducing the compressed data from the recording medium, wherein when the input video signal and audio signal are analog signals, the input video signal and the audio signal are converted into digital signals by analog / digital converting means,
The converted digital video signal and digital audio signal are sent to the compression generation means. If the input video signal and audio signal are already compressed digital signals, the input signal is recorded as it is on the recording medium. A digital recording / reproducing apparatus characterized by the above-mentioned. 2. A digital recording / reproducing apparatus according to claim 1, further comprising receiving means for receiving an analog video signal and an analog audio signal, wherein said analog video signal and analog audio signal are input. Recording and playback device. 3. The digital recording / reproducing apparatus according to claim 1, wherein a magnetic tape or a disk-shaped recording medium is used as said recording medium. 4. A compression generating means for performing compression processing on a digital video signal and a digital audio signal to obtain compressed data, and a decompression generating means for performing expansion processing on the compressed data to obtain original digital video signals and digital audio signals. Recording means for recording the compressed data on a recording medium,
A digital recording / reproducing apparatus comprising: a reproducing unit for reproducing the compressed data from the recording medium; an analog signal reproducing unit for reproducing a recording medium on which an analog video signal and an analog audio signal are recorded; Means for converting a video signal and an analog audio signal into digital signals by analog-to-digital conversion means and sending them to the compression generation means; and digital output means for outputting compressed data from the compression generation means to the outside. A digital recording / reproducing apparatus characterized by the above-mentioned. 5. The digital recording / reproducing apparatus according to claim 1, wherein said compression generating means includes a compression rate setting means capable of setting an arbitrary compression rate. Digital recording and playback device. 6. A digital recording / reproducing apparatus according to claim 5, wherein said compression rate setting means is adapted to set a fixed compression rate to a fixed compression rate, and adaptively according to input video signals and audio signals. A digital recording / reproducing apparatus, comprising: a compression rate changing unit that changes a compression rate. 7. A digital recording / reproducing apparatus according to claim 6, wherein said variable compression rate means includes a compression rate upper limit value setting means for setting an upper limit value of a compression rate. . 8. A digital recording / reproducing apparatus according to claim 6, wherein said compression rate varying means includes means for changing a compression rate according to a remaining recording capacity of said recording medium, a scheduled recording time, and said compression rate set value. A digital recording / reproducing apparatus comprising an adaptive compression rate varying means for resetting the compression rate.