JPH08307822A - Recording and reproducing device for digital signal - Google Patents

Abstract

PURPOSE: To select one program among plural programs at reproduction and to display the selected program by recording streams on which plural programs are multiplexed as they are. CONSTITUTION: An error correction code for recording and reproduction is added at a pre-processing section 31 to packets of plural programs subject to error correction by an error correction decoder 204 in the case of recording and the resulting signal is recorded by a digital signal recording reproducing section 303. A bit stream reproduced by a reproduction section 303 is subject to error correction generated at recording and reproduction at a post-processing section 305 and the result is given to a program selector 205 via a terminal (d) of a switch 401. Then an object packet is extracted by a selection signal of a program desired by the user received from a program selection terminal 214 and the result is a stream on which a packet of a single program is multiplexed and it is given to a separator 206, in which an audio signal or the like is reproduced. Thus, the user selects a preferred video image sequentially at reproduction and the image is watched.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for recording / reproducing digital television broadcasting, and more particularly to a recording / reproducing apparatus compatible with broadcasting for multiplexing and transmitting a plurality of programs.

[0002]

2. Description of the Related Art In place of conventional analog television signals, digital broadcasting for transmitting digitized signals to homes is about to start. In this background, ISO /
MPEG, an international standard defined by IEC and ITU-T
Digital image compression technology represented by (Moving Picture Experts Group) and 8VSB (Vestigial Side Band), 64Q
AM (Quadrature Amplitude Modulation) and OFDM (Orthogon
Digital modulation techniques such as al Frequency Division Multiplexing) have made significant progress. In digital broadcasting, by using these technologies together, conventional multi-channel transmission is performed by multiplexing and transmitting multiple programs in the band for one channel, making it possible to provide various services such as video-on-demand. Become.

In the United States, some satellite broadcasting has already started broadcasting in such a form, and other CATV operators are also conducting experiments. In Europe, digital broadcasting systems supporting satellite broadcasting, CATV, and terrestrial broadcasting are being standardized. Even in Japan, experiments and other activities centered on the Ministry of Posts and Telecommunications are being actively conducted.

FIG. 6 is a block diagram showing the basic structure of a general transmitter for such digital broadcasting. 101 and 109 are analog video signal input terminals, 102 and 110 are analog audio signal input terminals, and FIG. 103 and 111 are video encoders that digitally compress analog video signals and output video streams. 104 and 112 are audio encoders that digitally compress analog audio signals and output audio streams. 10
7 and 115 are control units, 108, 116 and 117 are first, second and third multiplexers for multiplexing a plurality of streams and outputting them as a single stream, and 105 and 113 are ciphers for encrypting pay programs. , 118 is an error correction encoder, 119 is a digital modulator,
120 is a transmitter and 121 is an output terminal.

The transmitter of FIG. 6 multiplexes two programs and sends them. The video signal and the audio signal forming the first program are input from the input terminals 101 and 102, respectively, and are digitally compressed and encoded by the encoders 103 and 104 to form a bit stream. This bit stream is time-division-multiplexed by the first multiplexer 108 together with a stream of control data or the like output from the control unit 107 to form one stream. Time division multiplexing means dividing a plurality of bit streams into packets each having a certain length, compressing them along the time axis, and switching these to form one stream. Information called a header for identifying the attribute of the packet is added to the head of each packet.
In the transmitting apparatus of FIG. 6, the type of video, audio, etc. and the program number are included in the header. Here, for a pay program, the stream for one program output from the multiplexer 108 is encrypted (scrambled) by the encryption unit 105, and viewing by a person who does not have the encryption key becomes impossible.

On the other hand, similarly for the second program, the signals input from the input terminals 109 and 110 are converted, multiplexed by the second multiplexer 116, and encrypted by the encryption unit 113. Is output. The stream of the first program output by the encryptor 105 and the stream of the second program output by the encryptor 113 are further time-division multiplexed by the third multiplexer 117, and packets of the two programs are multiplexed. One stream is obtained. Two programs are multiplexed here, but a plurality of programs can be similarly multiplexed. The output of the third multiplexer 117 is the error correction encoder 1
After adding a parity for error correction to each packet at 18, it is modulated by the digital modulator 119 and output to the output terminal 121 through the transmitting unit 120.

FIG. 7 is a block diagram showing the basic structure of a general receiving apparatus for receiving a digital broadcast signal by the above transmitting apparatus, in which 201 and 202 are input terminals for a digital modulated signal and its receiving section, 203 is a digital demodulator that demodulates the received digital modulated signal to extract the original bit stream, 204 is an error correction decoder, 205 is a packet in which multiple programs are multiplexed, and only packets of a specific program are extracted and output Program selector, 206 is program selector 2
Separator that separates each packet of video, audio, and control data from the output of 05 and outputs each individual stream, 20
7 is a control unit, 208 is a decryption unit, 210 and 212 are video decoders and their output terminals for expanding a digitally compressed video stream, and 211 and 213 are audio decoders and their output terminals for expanding a digitally compressed audio stream. , 214 are input terminals for a program selection signal from the user.

In FIG. 7, the digital modulation signal received by the receiving section 202 through the input terminal 201 is demodulated by the demodulator 203, and then the error correction decoder 204 corrects the error generated during the transmission, and the program selector Supplied to 205. Although the packets of a plurality of programs are multiplexed in the output of the error correction decoder 204, the user selects a desired program from these and inputs a program selection signal from the input terminal 214. The program selector 205 checks the program number contained in the header of each packet, separates only the packet of the program instructed by the selection signal, and supplies it to the decryption unit 208. When the user desires to watch the pay program, the decryption unit 208 obtains the encryption key by some method and decrypts the encryption. At this time, the fee is collected by preparing a mechanism that charges the program according to the time when the program is viewed.

The output of the decryption unit 208 is supplied to the separator 206, and depending on the attribute information contained in the header, the video, audio,
Separated into each individual stream of control data,
Finally, the decoders 210 and 211 restore analog video signals and audio signals and output them to the output terminals 212 and 213. In this way, it is possible to receive multi-channel broadcasting of digitally compressed video.

When recording / reproducing a digital broadcast at each home, the current analog system VTR must decode the digital signal to restore the original analog signal and then record the signal, resulting in deterioration. Do not take advantage of it. Therefore, a new method of VTR is expected, in which a digital signal is recorded as it is without being decoded and is decoded at the time of reproduction. Since such a VTR is not affected by deterioration that occurs during recording / reproduction of a signal, it has a feature that the reproduced signal can maintain high image quality and high sound quality of the original signal. However, in a digitally recorded VTR, many duplicates identical to the original signal can be created, which is problematic in terms of fee collection and copyright protection of pay programs.
In order to solve this problem, it is necessary to record in the state of the above-described encrypted bit stream so that the encryption can be released at the same time as the reproduction so that the fee can be charged.

Considering the above requirements, a VTR for digital broadcasting generally has a structure shown in the block diagram of FIG. In FIG. 8, reference numeral 300 denotes a digital signal recording / reproducing apparatus, which includes a pre-processing unit 301 for performing error correction coding, a post-processing unit 305 for correcting errors generated in the recording / reproducing process, and a digital signal recording / reproducing device. It is composed of the unit 303. 306
Is a changeover switch. The parts corresponding to those in FIG. 7 are designated by the same reference numerals, and duplicate description will be omitted.

FIG. 8 shows that a digital signal is taken out from the middle of the receiving apparatus shown in FIG. 7 and recorded, and a reproduced digital signal is returned to display. When the user selects a program to be recorded and inputs the selection signal to the input terminal 214, the program selector 205 separates only the packet of the desired program from the received stream in which a plurality of programs are multiplexed according to the selection signal. It is supplied to the processing unit 301. The pre-processing unit 301 performs error correction coding processing suitable for recording and reproduction, and the digital signal recording and reproducing unit 303 records it.
During reproduction, the bit stream reproduced by the digital signal recording / reproducing unit 303 is supplied to the post-processing unit 305 for error correction and the like, and is supplied to the decryption unit 208 through the b terminal of the changeover switch 306. Therefore, every time the recorded signal is reproduced, the decryption of the code and the charging process are performed.
After that, it operates similarly to the receiving apparatus shown in FIG. The changeover switch 306 is for selecting whether to reproduce the received program as it is or to reproduce the signal recorded by the VTR. With this VTR device, the user can select and record and reproduce only one program from the multiplexed programs, and can avoid illegal duplication.

[0013]

[Problems to be Solved by the Invention] VT having the structure shown in FIG.
In R, packets of a plurality of multiplexed programs are obtained up to the program selector 205, but only one of the packets is recorded. Therefore, it is not possible to meet the demand for recording a plurality of programs at the same time (recording a back program). In addition, as one digital broadcasting service, a broadcast program in which a video captured by a plurality of cameras in a broadcast program such as a sport or a concert is multiplexed and transmitted as it is, and a viewer views while switching to a video of a camera of his or her choice. However, it is impossible to record such a broadcast.

An object of the present invention is to provide a recording / reproducing apparatus for digital broadcasting capable of recording a stream in which a plurality of programs are multiplexed as it is and selecting and displaying one of the plurality of programs during reproduction. Especially.

Another object of the present invention is to provide a flexible recording / reproducing apparatus for digital broadcasting capable of reproducing a recording medium in which only a single program is recorded or a recording medium in which a plurality of programs are recorded while being multiplexed. To provide.

[0016]

The above object is to provide a receiving means for receiving a stream in which video and audio of a plurality of programs are digitally compressed and multiplexed, and an input terminal of a selection signal for instructing a program selected by a user. , A program selecting means for separating only a packet of a specific program from a stream in which a plurality of programs are multiplexed according to the selection signal, and a decoding for decompressing video and audio of a stream of a single program and converting them into original analog signals Means, a digital signal recording / reproducing means for extracting and recording a stream output by the receiving means in a state where a plurality of programs are multiplexed, and the program by switching the output of the digital signal recording / reproducing means and the output of the receiving means. This can be achieved by providing selection means for supplying the selection means.

[0017]

Since the digital signal recording / reproducing means records the output of the receiving means as it is, the packets of all multiplexed programs can be recorded. When reproducing this signal, the stream in which the packets of a plurality of programs are multiplexed is supplied to the program selecting means through the selecting means, so that the user can select one from the plurality of multiplexed programs. When the selection signal of the program selected by the user is supplied from the input terminal, only the packet of the target program is separated by the program selection means, and the decoding means restores the original video or audio to be displayed.

[0018]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a first embodiment of a digital recording / reproducing apparatus according to the present invention, and 401 is a changeover switch.

In FIG. 1, unlike the example shown in FIG. 8, the packet of a plurality of programs error-corrected by the error correction decoder 204 at the time of recording is different from the example shown in FIG. A digital signal recording / reproducing unit with a correction code added
Recorded at 303. The bit stream reproduced by the digital signal recording / reproducing unit 303 is corrected by the post-processing unit 305 for an error generated during recording / reproducing, and then input to the program selector 205 through the d terminal of the switch 401. Input terminal 214 here
A target packet is extracted in accordance with a program selection signal desired by the user, which is input to the demultiplexer 206 as a stream in which only packets of a single program are multiplexed. After that, the same operation as in the example of FIG. 8 is performed to reproduce video and audio. The switch 401 selects the d terminal during reproduction, and selects the c terminal when reproducing the received signal in real time.

According to the present embodiment, since the received stream can be recorded while a plurality of programs are multiplexed, it is possible to select a desired program during reproduction. In addition, it is possible to record and reproduce a multi-view broadcast program that simultaneously broadcasts images of a plurality of cameras described above. Here, with respect to multi-view broadcasting, an example of a system will be shown and described below.

FIG. 9 shows a schematic block diagram of the entire system for transmitting / receiving multi-view broadcasting and recording / reproducing the same. 901, 90
2, 903 are N cameras, 904, 905, and 906 are N video encoders for digitally compressing and encoding video images captured by the cameras, 907, 908, and 909 are M microphones, 910,
Reference numerals 911 and 912 are M voice encoders for digitally compressing and encoding voices, 913 is a multiplexer, 914 is a transmission unit, and 915 is a reception unit.

In FIG. 9, the images captured by the N cameras 901, 902 and 903 are N image encoders 904, 905 and 906.
Then, each of them is individually compression-coded into N video streams. In addition, M microphones 907, 908, 909
The audio signals output from the M audio encoders 91 are
It is digitally compressed and encoded by 0, 911, and 912 to become M audio streams. N video streams output from the video encoders 904, 905, and 906 and the audio encoder 91
The M audio streams output from 0, 911, and 912 are time-division multiplexed by the multiplexer 913 into one stream, which is transmitted from the transmission unit 914. Next, the signal received by the receiving unit 915 is supplied to the digital signal recording / reproducing apparatus 300, and the images from the N cameras and the voices from the M microphones are recorded while being multiplexed. At the time of reproduction, an output signal of the digital signal recording / reproducing apparatus 300 is supplied to the program selector 205 via the changeover switch 401. Instead of selecting a program, the program selector 205 selects a video stream and an audio stream from the viewpoint specified by the user and supplies them to the separator 206. The video and audio are separated by the separator 206, expanded by the video decoder 210 and the audio decoder 211, and output from the output terminals 212 and 213. As described above, each of the plurality of video streams and audio streams included in a single channel is handled as a stream of an individual program (individual video and audio) by the program selector 205, so that the user can When reproducing the signal output by the recording / reproducing apparatus 300, it is possible to watch while switching to a different viewpoint image or different sound.

FIG. 2 is a block diagram showing another embodiment of the digital recording / reproducing apparatus according to the present invention, in which 402 is a changeover switch.

In FIG. 2, this embodiment is similar to the embodiment of FIG. 1 in addition to the first mode in which a plurality of programs are recorded and reproduced while being multiplexed, and in the same manner as the example shown in FIG. The second mode in which a program is selected and recorded and reproduced is provided. In the first mode, the switch 401 is the d terminal and the switch 4
02 selects the e terminal, switch 306 selects the a terminal, and in the second mode, switch 401 is the c terminal and switch 402 is the f terminal.
The terminal and switch 306 selects terminal b. In addition, when reproducing the received signal in real time, switch 401
Is the c terminal, switch 306 is the a terminal, and switch 402
Can be either. It is necessary to change the recording or reproducing bit rate of the digital signal recording / reproducing unit 303 according to the stream handled in each mode. For example, when recording / reproducing with a magnetic tape, the tape running speed is changed. It can be realized by a method such as.

According to the present embodiment, by setting the switches as described above, it is possible to record and reproduce both the signal in which a plurality of programs are still multiplexed and the signal of a single program, and the user can use them as needed. Either mode can be selected.

FIG. 3 is a block diagram showing another embodiment of the digital recording / reproducing apparatus according to the present invention.

In FIG. 3, this embodiment eliminates the changeover switch 306 in FIG. 2 and inputs the reproduction signal of a single program to the program selector 205 through the d terminal of the changeover switch 401. The changeover switch 401 selects the c terminal for real-time reproduction and recording of a single program, and selects the d terminal for reproducing a plurality of programs and a single program. Further, the switch 402 selects the terminal e when recording a plurality of programs, and selects the terminal f when recording a single program.

The operation of this embodiment is the same as that of the embodiment shown in FIG. 2 except when a single program is reproduced, and therefore its explanation is omitted.
The reproduction signal of the single program is subjected to processing such as error correction decoding in the post-processing unit 305, and is input to the program selector 205 through the d terminal of the switch 401. The program selector 205 originally separates a packet of a specific program from a stream in which a plurality of programs are multiplexed, but also when a stream in which only a packet of a single program is multiplexed is input. It is processed without any inconvenience, and all packets are extracted and output. From this point onward, the same processing as in the embodiment of FIG. 2 is performed and reproduction is performed.

In this embodiment, since the mode switching switch 306 is eliminated, the circuit can be simplified.

FIG. 4 is a block diagram showing another embodiment of the digital recording / reproducing apparatus according to the present invention.

In FIG. 4, the switch 402 in FIG. 3 is omitted to eliminate the distinction between the single program mode and the plural program mode, and the output of the program selector 205 is recorded in any case. However, in the program selector 205, a packet of an arbitrary M program (where M is a positive integer equal to or less than N and determined by a user's instruction) from a stream in which packets of N programs (where N is a positive integer) are multiplexed. Shall be output separately. Therefore, when M = N, packets of all programs are recorded as in the embodiment shown in FIG. 1, and M =
When it is 1, only a packet of a single program is recorded as in the example shown in FIG. When M <N and M> 1, a stream in which packets of an arbitrary number of programs selected by the user are multiplexed is recorded. At the time of reproduction, regardless of how many programs are multiplexed in the stream output by the digital signal recording / reproducing unit 303, one of the programs is selected and displayed by the program selector 205.

According to the present embodiment, even when a plurality of programs are recorded, the user can select only the program he / she wants to record, so that a recording medium such as a magnetic tape can be saved without recording an unnecessary program. In addition, the circuit is simple because no switch for mode switching is required.

Another embodiment of the digital recording / reproducing apparatus according to the present invention will be described with reference to FIG. 5 (a) and FIG.
(B) shows the pre-processing unit 301 and the post-processing unit 3 in the embodiment shown in FIG.
It is the figure which showed the internal structure of 05, 501 and 504 are pre-processing parts.
An input terminal and an output terminal of 301, 502 and 503 are first and second error correction encoders, 505 and 508 are input terminals and output terminals of the post-processing unit 305, and 507 is a first error correction encoder 502. Is a first decoder corresponding to, and 506 is a second decoder corresponding to a second error correction encoder 503. FIG. 5C is a block diagram showing this embodiment.

In FIGS. 5A and 5B, the input terminal 501
The signal input to the preprocessing unit 301 through is error-correction encoded by the first error-correction encoder 502, and is further error-correction encoded by the second error-correction encoder 503. It is output from the output terminal 504. For these two encodings, for example, a general Reed-Solomon code is used in the first encoder, and a Reed-Solomon code combined with effective interleaving for burst errors is used in the second encoder. Different types of codes, such as those used, are used to increase the resistance to errors. At the time of error correction, the signal supplied to the post-processing unit 305 through the input terminal 505 is the second signal.
Error correction decoder 506 decodes the second code, and first error correction decoder 507 decodes the first code.

In the present embodiment shown in FIG. 5C, the error correction code used in the transmission system and the first error correction code used in the recording / reproducing system of the embodiment shown in FIG. The first error correction encoder 502 of the processing unit 301 is omitted, and the error correction decoder 204 in the receiving device is replaced by the first decoder of the post-processing unit 305.
It is also used as 507 and moved after the changeover switch 401. However, it is assumed that the error correction decoder 204 outputs the decoding result with the parity part added. The changeover switch 401 selects the c terminal at the time of recording and real-time reproduction of the received signal, and selects the d terminal at the time of reproducing the output signal of the recording / reproducing unit.

In FIG. 5C, the received stream is supplied to the error correction decoder 204 through the c terminal of the switch 401, and the error generated during the transmission is corrected. At this time, in the normal decoding process, only the information bit excluding the parity is output, but the decoder 204 similarly corrects the error in the parity, and outputs the information bit while adding it to the information bit.
In this embodiment, since the first error correction code of the recording / reproducing system is the same as that of the transmitting system, the parity-added stream output from the decoder 204 is valid even in the recording / reproducing system, and the first error in the recording / reproducing system. It is equal to the state where the correction coding is performed. This stream with parity is supplied to the second error correction encoder 503 in the recording / reproducing apparatus, is subjected to the second error correction code, and is recorded by the digital signal recording / reproducing unit 303. The reproduction signal output from the digital signal recording / reproducing unit 303 is the second error correction decoder 50 in the recording / reproducing apparatus.
The second code is decoded at 6 and supplied to the error correction decoder 204 in the receiving device through the d terminal of the changeover switch 401 to decode the first code and supplied to the program selector 205. After that, the operation is similar to that of the embodiment shown in FIG.

According to this embodiment, one error correction encoder and one error correction decoder can be eliminated. Further, like the present embodiment, it is possible to reduce the number of encoders and decoders in the embodiments shown in FIGS. 3 and 4 by using the same error correction code. Further, in the present embodiment, the number of stages of error correction coding in the transmission system is one and the number of stages of error correction coding in the recording / reproducing system is two. However, both of them have more stages of error correction coding depending on the application. It may be processed. In such a case, the circuit can be simplified by making the error correction code for each stage common as in the present embodiment.

[0039]

According to the present invention, the multiplexed program can be recorded as it is by changing the position of taking out the signal to be recorded by the recording / reproducing apparatus for digital broadcasting.
It becomes possible to select a program during playback. In addition, it is possible to record a program in a form that multiplexes and broadcasts images from multiple cameras installed at venues such as sports and concerts, and the user can switch to the desired image and watch it while playing it back. Becomes Further, by changing the position of inputting the reproduced signal, it is possible to simplify the configurations of the error correction encoder and the decoder, and it is possible to reduce the cost.

[Brief description of drawings]

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

FIG. 2 is a block diagram of a recording / reproducing apparatus for digital broadcasting according to another embodiment.

FIG. 3 is a block diagram of a recording / reproducing apparatus for digital broadcasting according to still another embodiment.

FIG. 4 is a block diagram of a recording / reproducing apparatus for digital broadcasting according to still another embodiment.

5 is a block diagram showing an example of an internal configuration of a pre-processing unit and a post-processing unit in the embodiment shown in FIG. 3 and a block diagram of a digital broadcast recording / reproducing apparatus according to another embodiment.

FIG. 6 is a block diagram of a general transmission device that transmits a digital broadcast.

FIG. 7 is a block diagram of a general receiving apparatus that receives digital broadcasting.

FIG. 8 is a block diagram of a general recording / reproducing apparatus for digital broadcasting.

FIG. 9 is a block diagram of a system for transmitting / receiving multi-view broadcasting and recording / reproducing.

[Explanation of symbols]

 202, 203, 204 ... Receiving means, 205 ... Program selecting means, 210, 211 ... Decoding means, 303 ... Digital signal recording / reproducing means, 401 ... First selecting means, 202, 203 ... Pre-processing means, 204 ... Error correcting means.

Front page continuation (72) Kenji Katsumata, inventor 292 Yoshida-cho, Totsuka-ku, Yokohama, Kanagawa, Ltd.Video Media Research Laboratory, Hitachi, Ltd. (72) Takanori Eda, 292 Yoshida-cho, Totsuka-ku, Yokohama, Kanagawa Hitachi, Ltd. Video Media Laboratory (72) Inventor Toshio Oku, 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Hitachi, Ltd. Video Media Laboratory

Claims (7)

[Claims] Claims: 1. Receiving means for receiving a signal in which a plurality of programs of program data composed of digitally compressed and encoded video signals and audio signals are extracted, and a digital signal, and a receiving means. To a digital compression coded program, including program selection means for separating data of arbitrary N programs from the above, decoding means for expanding and reproducing the output signal of the program selection means, and recording / reproducing means for digital signals. An apparatus for recording / reproducing and outputting is provided with first selecting means for switching the output signal of the receiving means and the output signal of the recording / reproducing means to supply to the program selecting means, and the program selecting means receives the program at the time of recording. N programs are selected from the output signals of a plurality of programs of the means and supplied to the recording / reproducing means, and at the time of reproduction, from the output signals of the N programs of the recording / reproducing means. A digital signal recording / reproducing apparatus capable of selecting one program and supplying it to the decoding means, simultaneously recording an arbitrary number of programs, and selecting and reproducing a single program. . 2. A recording / reproducing apparatus for a digital signal according to claim 1, wherein an input signal of said recording / reproducing means is an output signal of said receiving means. 3. A digital signal recording / reproducing apparatus according to claim 2, further comprising second selecting means for switching between the output signal of said program selecting means and the output signal of said receiving means and supplying it to said recording / reproducing means. 4. The third aspect of claim 3, wherein the output signal of the recording / reproducing means and the output signal of the program selecting means are switched.
And a digital signal recording / reproducing apparatus which supplies the output signal of the recording / reproducing means to the decoding means through the third selecting means when the single program is reproduced. 5. A digital signal recording / reproducing apparatus according to claim 1, 2, 3 or 4, wherein said program selecting means separates and outputs one arbitrary program from an input signal in which a plurality of programs are multiplexed. 6. The preprocessing means according to claim 1, 2 or 3, wherein said receiving means performs a predetermined processing on said input signal,
Error correction means for performing error correction on the output signal of the preprocessing means, and the first selecting means supplies the error correction means by switching the output signal of the preprocessing means and the output signal of the recording / reproducing means. A digital signal recording / reproducing apparatus which supplies the output signal of the error correcting means to the program selecting means and supplies the digital signal in a state in which an error correction code is added to the recording / reproducing means. 7. A digital signal recording / reproducing apparatus according to claim 6, wherein said program selecting means separates and outputs one arbitrary program from an input signal in which a plurality of programs are multiplexed.