JP4277843B2 - Digital signal recording / reproducing apparatus and digital signal reproducing method - Google Patents

Description

  The present invention relates to an apparatus for recording and reproducing a video signal and an audio signal encoded by applying a high-efficiency encoding technique such as MPEG (Moving Picture Image Coding Experts Group) and a method for reproducing the same. The present invention relates to a technique for adding an identification signal indicating discontinuity or a variable speed reproduction mode.

  In recent years, in the United States and European countries, a high-efficiency encoding technology such as MPEG is applied to encode video signals and audio signals, transmit them via a communication satellite, etc., and demodulate them on the receiving side. Is spreading.

  In these systems, a dedicated receiving / demodulating device is required on the receiving side. In this receiving / demodulating device, a part for selecting a transport stream of a desired channel from a transport stream in which data of a plurality of channels is multiplexed, and video data and audio of a desired program from the transport stream of the desired channel A portion for separating data and a portion for decoding separated video data and audio data are provided.

  Also, in this system, a multiplexed transport stream is provided so that the reception / demodulation apparatus can receive the transport stream of the desired channel described above and separate the video data and audio data of the desired program. PSI (Program Spesific Information), EPG (Electronic Program Guide) or SI (Service Information) are added.

  Patent document 1 is known as a prior art.

JP-A-4-278741

  Video tape recorders (hereinafter referred to as DVTR) that encode and record / reproduce video signals and audio signals have been commercialized. Then, it is considered to record / reproduce the digital broadcast video data and audio data described above in this DVTR without decoding (edited by Yukio Kubota, “Illustrated Digital Video Reader”, pp. 140-152, (Ohm Co., Ltd., August 25, 1995).

  In the present invention, when a DVCR as described above continuously reproduces a plurality of digital broadcast programs and inputs them to the above-described receiver / demodulator, the decoding operation is performed when the program changes. It is an object of the present invention to provide a digital signal recording / reproducing apparatus and a digital signal reproducing method which can be performed quickly.

  Further, the present invention provides a digital signal in which the decoding output of video data and audio data is not interrupted when the output at the time of variable speed reproduction of the DVCR is input to the receiving / demodulating device described above and decoded. It is an object to provide a recording / reproducing apparatus and a digital signal reproducing method.

In order to solve the above-mentioned problems, a digital signal recording / reproducing apparatus according to the present invention includes a first means for inputting / outputting a digital signal encoded by a predetermined encoding method, and a first signal sent from the first means. Second means for recording an incoming digital signal on a recording medium, third means for reproducing the digital signal recorded on the recording medium and sending it to the first means, and a digital signal reproduced from the third means And a fourth means for detecting a change in the program, and when the fourth means detects a change in the program, the first identification information is added to the digital signal output from the first means . Output is performed so that the identification information of 1 and the digital signal are the same packet.

Also, the digital signal reproduction method according to the present invention is such that when a digital signal encoded by a predetermined encoding method is reproduced from a recording medium and output to the outside, the program of the digital signal being reproduced changes. In addition, the first identification information is added to the digital signal, and the first identification information and the digital signal are output in the same packet.

  In the digital signal recording / reproducing apparatus and the digital signal reproducing method according to the present invention, a second identification signal may be further added during variable speed reproduction.

  According to the present invention, the fourth means adds the first identification information to the digital signal output from the first means when detecting a program change in the digital signal reproduced from the third means. .

  When the reproduced data according to the present invention is input to the receiving / demodulating apparatus and decoded, the decoding operation at the time of program change can be performed quickly. In addition, when the output of the variable speed reproduction is input to the receiving / demodulating apparatus and decoded, the decoding output of the video data and the audio data can be prevented from being interrupted.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  First, a receiving / demodulating apparatus configured to receive and decode an MPEG digital signal reproduced by a digital signal recording / reproducing apparatus according to the present invention will be described.

  FIG. 4 is a block diagram showing the configuration of this receiving / demodulating apparatus. This receiving / demodulating device is called an IRD (Integrated Receiver Decoder).

  The receiving / demodulating apparatus receives an RF signal sent from a down converter (not shown), selects a transport stream of a desired channel, and a transport stream selected by the front end 21. A demultiplexer 22 that separates additional information from MPEG video data and MPEG audio data of a desired program, and a buffer memory 23 that temporarily stores data input and output through the demultiplexer 22 are provided.

  The receiving / demodulating apparatus includes an MPEG video decoder 24 for decoding the video data separated by the demultiplexer 22, an MPEG audio decoder 25 for decoding the audio data separated by the demultiplexer 22, and an MPEG video decoder 24. An NTSC encoder 26 that converts the decoded video signal into an NTSC video signal, a D / A converter 27 that converts the output of the NTSC encoder 26 into analog, and a D / A converter 28 that converts the output of the MPEG audio decoder 25 into analog. And. The MPEG video decoder 24 is provided with a buffer memory 24a for temporarily storing video data, and the MPEG audio decoder 25 is provided with a buffer memory 25a for temporarily storing audio data.

  Further, this receiving / demodulating apparatus externally transmits MPEG video data, MPEG audio data, and additional information separated by a microcomputer 29 (hereinafter referred to as a microcomputer) 29, a front panel 30, and a demultiplexer 22 for controlling the operation of the entire apparatus. And a digital interface 31 for transmitting MPEG video data, MPEG audio data, and additional information received from the outside to the demultiplexer 22.

  The front end 21 includes a tuner, a QPSK demodulator, and an error correction circuit. From the multiplexed transport streams of a plurality of channels, a transport stream of a desired channel specified by the user on the front panel 30 is obtained. Select and perform QPSK demodulation, and further detect and correct errors.

  FIG. 5 shows an example of a transport stream for one channel. As shown in this figure, a plurality of programs (here, program numbers 1 to 3 are illustrated) are multiplexed in a one-channel transport stream. Here, the program refers to a virtual broadcast channel, that is, a broadcast service such as NHK Satellite No. 1, NHK Satellite No. 2, etc., in the current Japanese broadcast.

  Data of each program is packetized with a predetermined length (188 bytes), and has a header at the head thereof. The header is given a PID (Packet Identification: packet ID) for identifying data.

  A packet including additional information is temporarily written in the buffer memory 23 from the transport stream of the desired channel selected by the front end 21 through the demultiplexer 22. Then, MPEG video data and MPEG audio data of a desired program are recognized and separated from here, and the video data is sent to the MPEG video decoder 24 and the audio data is sent to the MPEG audio decoder 25. In FIG. 9, video data and audio data of program number 2 are separated.

  In this separation, the PID (packet ID) assigned to the packet is viewed. If it is a PID for identifying video data and audio data of a desired program, it is sent to the MPEG video decoder 24 and the MPEG audio decoder 25, respectively. In FIG. 9, the PID assigned to the video data of program number 2 is “xx”, and the PID assigned to the audio data is “yy”. A method of knowing the correspondence between the program number and the PID in the receiving / demodulating apparatus will be described later.

  The video data sent to the MPEG video decoder 24 is stored in the buffer memory 24a, read out as appropriate, and decoded. The decoded video data is converted to an NTSC video signal by the NTSC encoder 25, converted to an analog video signal by the D / A converter 26, and then supplied to an external monitor device (not shown). The audio data sent to the MPEG audio decoder 25 is stored in the buffer memory 25a, and is read out and decoded as appropriate. The decoded audio data is converted into an analog audio signal by the D / A converter 28 and then supplied to a speaker (not shown) such as a monitor device.

  As described above, the digital broadcast video signal and audio signal can be received, decoded, and displayed on the monitor device.

  Next, additional information will be described. As described above, PSI (program specification information), EPG (electronic program guide), or SI (service information) is added to the multiplexed bit stream. Here, PSI defined by MPEG and SI defined by DVB (Digital Video Broadcasting) system which is European digital broadcasting will be described.

(1): PAT (Programme Association Table)
This table is defined by MPEG, and the PID (packet ID) is 0. The main contents are a description of the NIT PID and the PMT PID, which will be described later.

(2): PMT (Programme Map Table)
This table is also defined by MPEG, and the PID is determined by the PAT described above. The main contents are a description of the correspondence between the program number and the PID and a description of the PID of the ECM (scrambled data attached to the program).

(3): CAT (Conditional Access Table)
This table is also defined by MPEG, and the PID is 1. The main content is a description of EMM (scramble information for customers).

(4): NIT (Network Information Table)
The PID is 0010. The main contents are a description of the network name (satellite name, terrestrial transmitter, etc.) and a description of the modulation method and frequency for each transport stream (physical channel).

  The following table is defined in DVB.

(5): BAT (Bouquet Association Table)
The PID is 0011. The main contents are the name of the bouquet (program provider) and the description of the destination country, the contents of the service relating to the transport stream (physical channel), and the description of the CASS (Conditional Access Service System) system.

(6): SDT (Service Description Table)
The PID is 0011. The main contents of the transport stream (physical channel) are a description of the service ID included therein, the name of the bouquet, and the like. Here, the service ID is a broadcast channel such as the NHK satellite first and the NHK satellite second. That is, it is the same as the program number defined in MPEG.

(7): EIT (Event Information Table)
The PID is 0012. The main contents are description of event ID and its start time, broadcast time, program contents, and the like. A transport stream ID and a service ID are described for each event ID. Here, the event is, for example, a program such as “7 o'clock news (for December 1 broadcast)”.

(8): TDT (Time and Data Table)
The PID is 0010. The main content is a description of information in universal time. Using this TDT, the time of a clock (not shown) in the apparatus can be adjusted.

(9): RST (Running Status Table)
The PID is 0013. The main content is a description of the event execution status. In other words, a description such as before the start of an event, during execution, and the end is described.

  Next, how the microcomputer 29 in the receiving / demodulating apparatus processes the PSI and SI described above will be described.

  First, in the receiving / demodulating apparatus, constants and the like are set according to the method of each network. Since this information is described in the NIT, the modulation system, frequency, bit rate, error correction system, etc. are obtained for each transport stream. After the setting, these pieces of information are stored in an EEPROM (not shown) of the microcomputer 29.

  Next, an event search is performed using the EIT. Each broadcast event is given a unique event ID, the name and contents of the broadcast program are described in the EIT together with the start time, and the transport stream ID and service ID are described for each event. Therefore, the transport stream ID is discriminated from the EIT, the reception / demodulation apparatus is set using the transport stream constant obtained by the NIT, and the transport stream of the desired channel is selected.

  In the above, the process at the time of selecting the transport stream of a desired channel in the front end 21 was demonstrated. Next, the processing of the microcomputer 29 when sending the output of the demultiplexer 22 to the MPEG video decoder 24 and the MPEG audio decoder 25 will be described.

  FIG. 6 shows an example of the transport stream input to the demultiplexer 22 and the contents of the PAT and PMT therein. FIG. 7 shows an internal configuration example of the buffer memory 23. FIG. 8 shows the flow of this process. Here, it is assumed that the broadcast with program number 1 is selected.

  First, as shown in step S 1 of FIG. 8, the output of the front end 21 is written into the buffer memory 23 through the demultiplexer 22. In the buffer memory 23, as shown in FIG. 7, storage areas 23A to 23C are determined for each data, and thus data is written in each area.

  Next, as shown in step S2, the PAT is searched from the additional information written in the additional information area 23C of the buffer memory 23. This process may be performed by searching for a packet with a PID of 0. As shown in FIG. 6B, the PAT describes the PID of the PMT for each program (here, the PID of the PMT1 is “cc” and the PID of the PMT2 is “dd”).

  Therefore, the packet with the PID “cc” is searched for next. Thereby, the PMT1 corresponding to the program number 1 can be detected. As shown in FIG. 6 (3), PMT1 describes MPEG video data, MPEG audio data, and ECM PID of program number 1.

  Therefore, when viewing the broadcast of program number 1, a packet with PID “aa” is read from the MPEG video data area 23A of the buffer memory 23, sent to the MPEG video decoder 24 through the demultiplexer 22, and from the MPEG audio data area 23B. A packet whose PID is “ab” is read and sent to the MPEG audio decoder 25 through the demultiplexer 22. As shown in FIG. 5, only the data excluding the header is sent at this time. Also, the scramble is decoded using the ECM information described in the packet whose PID is “xx”.

  If a broadcast with program number 2 is viewed, a packet with a PID of “dd” is similarly searched. In this packet, as shown in FIG. 6 (4), video data, audio data, and ECM PID of program number 2 are described. Therefore, a packet with PID “ba” is read from the MPEG video data area 23A and sent to the MPEG video decoder 24, and a packet with PID “bb” is read from the MPEG audio data area 23B and sent to the MPEG audio decoder 25. Also, the scramble is decoded using the ECM information described in the packet whose PID is “zz”.

  The normal processing for decoding the transport stream input from the front end 21 has been described. 4 can further output the MPEG video data, the MPEG audio data, and the additional information separated by the demultiplexer 22 to an external recording / reproducing apparatus, for example, a DVTR, via the digital interface 31. Also, MPEG video data, MPEG audio data, and additional information output from an external recording / reproducing apparatus can be received via the digital interface 31 and sent to the demultiplexer 22. Next, these processes will be described.

  First, the processing of the microcomputer 29 when the output of the demultiplexer 22 is sent from the digital interface 31 to the outside will be described. Since most of this processing is the same as the normal processing described above, only the differences will be described.

  MPEG video data and MPEG audio data are sent to the digital interface 31 with a packet header attached. That is, when the microcomputer 29 reads from the buffer memory 23, the header is read and sent to the digital interface 31 through the demultiplexer 22.

  PSI and SI are also sent to the digital interface 31 with the header attached. However, the PAT leaves only the PID that specifies the PMT of the selected program number and removes the others. For example, when program number 1 is selected, only the PID of PMT1 (“cc” in the case of FIG. 6) remains, and the others are removed.

  The data sent to the digital interface 31 in this way is sent out from here. The digital interface 31 is compliant with, for example, IEEE-1394. In this case, the data is output in an IEEE-1394 isochronous packet. The isochronous packet output from the digital interface 31 is sent to an external DVTR.

FIG. 9 shows the format of the isochronous packet described above. When the tag (tag) 2-bit field is _012, it inserts a 2 Kuadoretto common isochronous packet header (hereinafter referred to as CIP header) at the beginning of the data field. For the purpose of dealing with real time data in a digital audio video signal, such as digital video equipment and digital audio equipment, the value of the tag 01 _2. Figure 10 shows a CIP header when taking the value of the tag = 01 _2. FIG. 11 shows an example of allocation of FMT (format type) in the CIP header. In this embodiment, it specifies the format of the MPEG signal transmission FMT = 100001 _2. Then, MPEG data is put in the data block after the CIP header shown in FIG.

  FIG. 1 is a block diagram showing the configuration of a DVTR to which the present invention is applied. This DVTR has a function of encoding / recording / reproducing an analog video signal and a function of recording / reproducing an MPEG digital signal input from the outside.

  First, recording / reproduction of an analog video signal will be described. This DVTR is an A / D converter 1 for digitizing a video signal to record an analog video signal, and DCT (discrete cosine transform), quantization, variable length code for the output of the A / D converter 1 A data compression coding circuit 2 that performs data compression coding processing such as conversion, and a framing circuit 3 that frames the output of the data compression coding circuit 2 are provided.

  The DVTR also includes a multiplexer 4 that synthesizes the output of the framing circuit 3 and video auxiliary data (VAUX data) created by a signal processing microcomputer 8 described later, and an error correction code that adds an error correction code to the output of the multiplexer 4. An addition circuit 7 and a channel encoder 6 that performs recording modulation processing on the output of the error correction code addition circuit 7 are provided.

  Furthermore, this DVTR is a mode processing microcomputer 7 for generating information signals such as TV channels of video signals and recording date / time based on user operations, etc., and for creating VAUX data based on the output of the mode processing microcomputer 7 And a signal processing microcomputer 8 to perform. Here, the VAUX data includes a TV channel, a recording date and time, a recording start position (REC START), a recording end position (REC END), and the like on the video tape.

  FIG. 2 shows a format of one track of data output from the error correction code adding circuit 5. As shown in this figure, video data and VAUX data are formed in units of 90-byte blocks. This data is subjected to recording modulation processing in the channel encoder 6, amplified by a recording amplifier (not shown), and recorded on a video tape (not shown) using a magnetic head (not shown). In an actual DVTR, audio data, subcode data, and the like are recorded on a track in a time-division manner together with video data and VAUX data.

  The analog video input signal is encoded and recorded as described above. Next, reproduction of recorded video signals will be described.

  This DVTR is reproduced from a video tape and reproduced by a reproduction circuit 9 for performing equalization of the waveform of the data amplified by a reproduction amplifier (not shown), reproduction of a data clock, etc. A channel decoder 10 that performs processing, an error correction circuit 11 that performs error correction processing on the output of the channel decoder 10, a demultiplexer 12 that separates video data and VAUX data from the output of the error correction circuit 11, and the video A deframing circuit 13 for decomposing data frames, a data compression decoding circuit 14 for performing processing such as variable length code decoding, inverse quantization, inverse DCT on the output of the deframing circuit 13, and data compression decoding And a D / A converter 15 for converting the output of the conversion circuit 14 into an analog video signal. The VAUX data separated by the demultiplexer 12 is sent to the signal processing microcomputer 8 and from here to the mode processing microcomputer 7.

  Next, recording / reproduction of an encoded signal input from the outside will be described. This DVTR includes a digital interface 16. The digital interface 16 is configured in the same manner as the digital interface 31 in the receiving / demodulating apparatus of FIG. Then, the IEEE-1394 packet is transmitted / received to / from the digital interface 31 of FIG.

  Next, an operation for recording MPEG data input from the digital interface 16 will be described. As described above, this MPEG data is transmitted in an isochronous packet from the digital interface 31 of the receiving / demodulating apparatus of FIG.

  First, MPEG data, that is, MPEG video data, MPEG audio data, and additional information are separated from the isochronous packet in the digital interface 16. The separated data is sent to the multiplexer 4 through the switch SW1, where it is multiplexed with the VAUX data output from the signal processing microcomputer 8, and formed in the format of FIG. That is, MPEG video data, MPEG audio data, and additional information are all recorded in the video data recording area. The processing after the error correction code adding circuit 5 is the same as that for recording the analog video input signal described above.

  Next, processing during reproduction of MPEG data will be described. The processing at the time of reproduction is the same as that at the time of reproducing the video signal described above until the reproduction data is input to the demultiplexer 12. The reproduction data input to the demultiplexer 12 is separated into MPEG data and VAUX data here. The MPEG data is sent to the digital interface 16 through the switch SW2. The VAUX data is sent to the signal processing microcomputer 8.

  The digital interface 16 adds the header shown in FIG. 9 and FIG. 10 to the MPEG data and outputs it to the outside as an isochronous packet. The isochronous packet is input to the digital interface 31 of the receiving / demodulating device, where the original MPEG video data, MPEG video data, and additional information are extracted and written into the buffer memory 23 through the demultiplexer 22.

  The processing of MPEG video data and MPEG audio data written in the buffer memory 23 is the same as the processing of these data in the transport stream input from the front end 21 described above. On the other hand, the microcomputer 29 processes the PSI and SI written in the buffer memory 23 as follows.

  PAT and PMT are used as they are. As described above, when data is output from the receiving / demodulating device to the external DVTR, only the PID designating the PMT of the program number selected from the PAT is left and the others are removed. In the PAT in the data input from, only the PID specifying the PMT of the program number being input is described. Accordingly, the PMT can be searched by looking at the PAT, and the MPEG video data and MPEG audio data of the program being input can be read by looking at the PMT. The read MPEG video data and MPEG audio data are sent to the MPEG video decoder 24 and the MPEG audio decoder 25 through the demultiplexer 22, and thereafter processed in the same manner as these data from the front end 21.

  For EIT, only the actual and present information of the program described in the PAT is decoded, and the others are ignored. Here, actual means a transport stream of the selected channel, and present means that the selected program is currently being broadcast.

  For RST, only those related to the program described in the PAT are decoded, and the others are ignored. For SDT, only the actual one of the program described in the PAT is decoded, and the others are ignored.

  NIT is necessary for setting in the front end 21, but is ignored in the demultiplexer 22 because it is not necessary. Similarly, BAT is ignored.

  As for TDT, when an external DVTR playback signal is input, the TDT in the playback signal indicates the time at the time of recording and does not indicate the current time, so this TDT is ignored. As a result, it is possible to avoid a situation where the internal clock is set to an incorrect time.

  Further, a case where a plurality of programs are continuously input from an external DVTR will be described. As described above, the microcomputer 29 looks for the PMT by looking at the PAT, and reads the MPEG video data and MPEG audio data of the program being input from the external DVTR by looking at the PMT. However, when the external DVTR outputs a plurality of programs continuously, if the program is switched, the microcomputer 29 newly looks at the PAT to search for the PMT, and the MPEG video data of the switched program and MPEG audio data cannot be read out. In addition, since the MPEG video decoder 24 and the MPEG audio decoder 25 use past data for decoding processing, when the program is switched, the program data before switching remaining in the buffer memories 24a and 25a is stored. If it is not cleared, correct decoding cannot be performed.

  Similarly, when the SI is switched to a program having a different transport stream, the SI in the buffer memory 23 needs to be rewritten.

  Therefore, in the present embodiment, when the program being played back by the DVTR changes, a flag for identifying it is provided in the header of the isochronous packet. That is, a discontinuity flag is provided in bit b0 of FDF in FIG.

  This discontinuity flag is set to the “H (high)” level for a predetermined time (for example, 1 second) when the transport stream becomes discontinuous in the playback signal of the DVTR. Specifically, when the signal processing microcomputer 8 detects data indicating the recording start position (REC START) or the recording end position (REC END) in the reproduction VAUX data sent from the demultiplexer 12, the digital interface 16 To inform the discontinuity flag to the “H (high)” level.

  In the receiving / demodulating device, when this discontinuity flag is detected by the digital interface 31, the microcomputer 29 rewrites the SI in the buffer memory 23, and the MPEG video decoder 24 and the MPEG audio decoder 25 respectively. A command to clear the buffer memories 24a and 25a is given.

  In the present embodiment, the above-described discontinuity flag is set to the “H (high)” level even when the DVTR mode changes from stop (STOP) to playback (PB). More specifically, the mode processing microcomputer 7 detects the user's PB operation, transmits it to the signal processing microcomputer 8, and the signal processing microcomputer 8 instructs the digital interface 16. Thereby, even when the DVTR is reproduced from the middle of the program, the data in the buffer memories 24a and 25a in the receiving / demodulating device can be cleared and the SI in the buffer memory 23 can be rewritten.

  Furthermore, in this embodiment, a variable speed regeneration flag is provided in the bit b1 of the FDF. This is a flag that is set to the “H (high)” level when the operation mode of the DVTR is slow and cue / review. During such variable speed reproduction, only the MPEG I picture becomes valid data, so the buffer memory 24a underflows. As a result, the output of the MPEG video decoder 24 is interrupted until the next I picture is decoded. Therefore, the receiving / demodulating apparatus is configured to continue outputting the last decoded I picture from the MPEG video decoder 24 until the next I picture is input when this variable speed reproduction flag is detected.

  The flag described above is shown in FIG. Here, NP is normal play data, and TP is trick play data. NP1 → NP2 indicates that the normal play program has changed.

  As described above in detail, when the reproduction data according to the embodiment of the present invention is input to the reception / demodulation apparatus and decoded, the decoding operation at the time of program change can be performed quickly. In addition, when the output of the variable speed reproduction is input to the receiving / demodulating apparatus and decoded, the decoding output of the video data and the audio data can be prevented from being interrupted.

  It should be noted that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention.

It is a block diagram which shows the structure of DVTR to which this invention is applied. It is a figure which shows the format for 1 track | truck of the data output from the error correction code addition circuit of FIG. It is a figure which shows the flag in DVTR to which this invention is applied. It is a block diagram which shows the structure of the receiving / demodulating apparatus comprised so that the output of the digital signal recording / reproducing apparatus concerning this invention might be received. It is a figure which shows the example of the transport stream for 1 channel. It is a figure which shows one example of the transport stream input into a demultiplexer, and the content of PAT and PMT in it. It is a figure which shows the internal structural example of the buffer memory 3 in FIG. It is a figure which shows the flow of a process of the microcomputer at the time of sending the output of a demultiplexer to an MPEG video decoder and an MPEG audio decoder. It is a figure which shows the format of an isochronous packet. It is a diagram showing a CIP header when taking the value of the tag = 01 _2. It is a figure which shows the example of allocation of FMT in a CIP header.

Explanation of symbols

  5 error correction code addition circuit, 6 channel encoder, 7 mode processing microcomputer, 8 signal processing microcomputer, 9 reproduction circuit, 10 channel decoder, 11 error correction circuit, 16 digital interface

Claims (4)

First means for inputting / outputting a digital signal encoded by a predetermined encoding method;
Second means for recording the digital signal sent from the first means on a recording medium;
Third means for reproducing the digital signal recorded on the recording medium and sending it to the first means;
And a fourth means for detecting a program change in the digital signal reproduced from the third means,
When the fourth means detects a change in the program, the first identification information is added to the digital signal output from the first means , and the first identification information and the digital signal become the same packet. A digital signal recording / reproducing apparatus that performs output as described above .   5. The apparatus according to claim 1, further comprising fifth means for inputting an operation mode, wherein the second identification information is added to the digital signal output from the first means when the variable speed reproduction mode is designated by the fifth means. The digital signal recording / reproducing apparatus as described. When a digital signal encoded by a predetermined encoding method is reproduced from a recording medium and output to the outside, the first identification information is added to the digital signal when the program of the digital signal being reproduced changes. A digital signal reproducing method for outputting the first identification information and the digital signal in the same packet .   4. The digital signal reproducing method according to claim 3, wherein the second identification information is added to the digital signal when performing variable speed reproduction.

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