JPH08340514A - Recording method for digital data, recording device and reproduction system - Google Patents

Abstract

PURPOSE: To provide a recording method of digital data to record a program supplied as a transport stream in the MPEG 2 system onto a recording medium, the recording device and the reproduction system. CONSTITUTION: The system is made up of a reception section 10 that receives an ATV signal, converts a desired program into a standard system television signal and provides an output of the converted signal and up of a recording and reproducing section 20 recording/reproducing a bit stream of a scramble broadcast received by the reception section 10. The recording and reproducing section 20 uses a program number as auxiliary data to reproduce data of each main packet and gives the data to the reception section 10 in the case of reproducing a data packet being a multiplexed packet between a main packet and a sub packet of plural programs from the recording medium.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION This invention is based on the MPEG (Moving P
icture Experts Group) The present invention relates to a recording method, a recording device, and a reproducing system of digital data for recording a transport packet of two types on a recording medium such as a magnetic tape.

[0002]

2. Description of the Related Art After converting a video signal into a digital signal, a so-called discrete cosine transform (hereinafter referred to as DCT: Discrete Cosine Tr
This is called ansform conversion. In addition, a digital video tape recorder (hereinafter simply referred to as a digital VTR) that records a digital video signal, which is data-compressed by variable length coding such as so-called Huffman coding, on a magnetic tape by a rotary head, that is, simply referred to as a digital VTR. Development is in progress. In such a digital VTR, NTSC
Mode (hereinafter, referred to as SD mode) for recording a video signal of a current television system such as a standard system, and a video signal for a so-called high-definition television system (hereinafter, HD: High Defin).
ition Television signal. ) Recording mode (hereinafter referred to as HD mode) can be set. And in SD mode, the video signal is about 25 Mb.
HD is recorded after being compressed into a ps digital video signal.
In the mode, the HDTV signal is compressed into a digital video signal of about 50 Mbps and recorded.

By the way, in this conventional digital VTR, it is considered that the input digital video signal, that is, the input data is directly recorded on the magnetic tape, and the data recorded on the magnetic tape is reproduced and directly output. . That is, by adding a function of directly recording / reproducing a digital video signal to a conventional digital VTR,
It is not necessary to decode an input digital video signal once, reproduce an HDTV signal, and then re-encode the HDTV signal by a predetermined encoding method and record it on a magnetic tape, which wastes hardware. It has the advantage of disappearing.

Using such a digital VTR, the International Organization for Standardization (so-called ISO) and the International Electrotechnical Commission (so-called I).
MPEG 2 which is a moving picture coding system standardized by WG (Working Group) 11 of SC (Sub Committee) in JTC (Joint Technical Committee) 1 of EC)
It is considered to record the Transport Packet of the.

Here, the above-mentioned MPEG is used as an encoding method.
The so-called ATV (Adva
nced television) method will be described.

FIG. 12 shows an AT adopting the MPEG2 system.
It is a block diagram showing a configuration of a transmission system of V system.

The transmission system of the ATV system shown in FIG.
It has a function to output one stream (data string) from multiple programs called Transport Streams (TS), and multiple encodings to which the video and audio signals that make up each program are supplied. Processing units 100A, 100B, ..., First packetization processing unit 110 to which program specification information (PSI: Program Specific Information) is supplied, contract information (EM
First: M: Entitlement Management Message)
Packetization processing unit 120, each of the coding processing units 100
A multiplexing processing unit 130 to which the stream of each program encoded by A, 100B, ... And the program specification information PSI and contract information EMM packetized by the packetization processing units 110 and 120 are supplied. The transport stream TS multiplexed by the multiplexing processing unit 130 includes a modulation processing unit 150 and the like supplied via the ECC encoding processing unit 140.

The encoding processing unit 100A includes a video compression encoder 101A to which a video signal forming the first program A is supplied, and an audio compression encoder 102A to which an audio signal forming the first program A is supplied. A first multiplexing processing unit 103A to which data such as teletext or subtitle data, which is additional information of the first program A, is supplied, and scramble processing to which ECM (Entitlement Control Message) data including a scramble key Ks1 is supplied. The unit 104A and the second multiplexing unit 105A are included.

In the encoding processing unit 100A, the first multiplexing processing unit 103A is configured so that the video signal and the audio signal forming the first program A are the video compression encoder 101A and the audio compression encoder 10.
The data is compressed by 2A and supplied, and these are multiplexed together with data such as caption data to form a PES (PES: Packetized Elementary Stream) packet in variable length units.

Here, the PES packet is, as shown in FIG. 13, a 24-bit head start code, an 8-bit stream ID, and a 16-bit P indicating the packet length.
ES packet length, optional PES header, PE
It is composed of S packet data (bytes).

The above-mentioned optional PES header is MPE.
2-bit "10" data for identifying G1 and 2-bit PE indicating whether or not the packet is scrambled and its type
1 indicating the S scramble control flag and packet priority
Bit PES priority flag, data arrangement indicator for data alignment display, 1-bit copyright flag indicating presence or absence of copyright, presentation time stamp (PTS: Presentation Time Stamp) flag, decoding time stamp (DTS: Decoding Tim)
e Stamp) flag, elementary stream (ES: Elemen
tary Stream) speed flag, digital storage media (DSM) trick mode flag, additional copy information flag, preceding packet CRC (Cycl)
ic Redundancy Code), various flags such as PES extension flags, PES header data length, optional fields, and stuffing bytes.

The optional field is
Presentation Time Stamp (PTS) and Decoding Time Stamp (DTS) corresponding to the above flags
And an elementary stream (ES: Elementary Stream)
Rate and digital storage media (DSM: Digtal S
torage Media) trick mode, additional copy information,
Preceding packet CRC (Cyclic Redundancy Code) and P
It consists of ES extension data.

Further, the PES extension data is composed of five types of flags and optional fields. This PE
The optional field of the S extension data is 128-bit PES personal data, 8-bit packet header field, 8-bit program packet sequence control data, 16-bit P-STD buffer, and
It consists of a PES extension field length of bits and PES extension field data.

In the encoding processing unit 100A, the first multiplexing processing unit 103A causes the PES in variable length units.
The packetized PES packet of the first program A is supplied to the second multiplexing processing unit 105A via the scrambling processing unit 104A, and the second multiplexing processing unit 105A has a fixed length of 188 bytes. It is packetized into a transport packet (TP: Transport Packet), and this transport packet TP is multiplexed to form a stream of the first program A.

In the scramble processing section 104A, the payload section of the stream of the first program A is scrambled based on the scramble key Ks1 given as the ECM data.

The scramble key Ks1 is sent to another CA (Conditional) by the second multiplexing processing unit 105A.
Access) information is encrypted, packetized as a transport packet TP as an ECM stream, and multiplexed together.

Further, the encoding processing unit 100B has a second
Video compression encoder 101B to which a video signal forming the program B is supplied, an audio compression encoder 102B to which an audio signal forming the second program B is supplied, and a teletext which is additional information of the second program B. First multiplexing processing unit 103B to which data such as subtitle data and subtitle data is supplied, scramble key Ks
The PES packet of the second program B is composed of a scramble processing unit 104B and a second multiplexing unit 105B to which ECM data including 2 is supplied.
It is packetized into packets and this transport packet TP is multiplexed to generate the stream of the second program B.

Each of the other encoding processing units (not shown) also packetizes the PES packet of each program into a fixed-length transport packet TP with the same configuration and multiplexes the transport packet TP to generate a stream of each program. To do.

The transport packet TP is 18
It has a fixed length of 8 bytes, and its header portion has format-specific information without packet data, whereby a packet required for reproducing a target program is selected and decoded.

FIG. 14 shows the structure of the transport packet TP. As shown in FIG. 14, a header is provided at the beginning of the transport packet TP,
A payload (information) is provided in this. In the header,
8-byte sync, transport error indicator that indicates whether or not there is an error in the packet, payload unit start indicator that indicates the start of the payload unit, transport priority that indicates the importance of the packet, and attributes of individual slithome of the packet Packet identification information (PID: Packet Identification) indicating
Transport scramble control that indicates the presence or absence of payload scrambling and type, adaptation field control that indicates the presence or absence of an adaptation field, a cyclic counter for detecting whether or not a packet has been discarded halfway, and additional information about individual streams. It consists of an adaptation field that can contain stuffing bytes.

The adaptation field includes an adaptation field length indicating the length of the adaptation field, a discontinuity indicator indicating that the system clock is reset and new contents, a random access indicator indicating a random access entry point, and an important point. It contains a priority stream elementary indicator that the part is in this payload and an optional field.

The optional field is a program clock reference (PCR).
And the original program clock reference (OPC
R: Oruginal OCR) and splice countdown,
It includes transport private data length and transport private data, an adaptation field extension length, and an optional field. Program clock reference PC
R is a time stamp for setting and calibrating a value serving as a time reference in MPEG system decoding.
The system clock (27 MHz) is reproduced from this program clock reference PCR by a phase locked loop (PLL) and the time axis information of these packets is held as a reference for the timing of the subsequent decoding processing. .

Further, each of the packetization processing units 110 and 1
20 converts the program specification information PSI and the contract information EMM described in a predetermined format into transport packets TP and supplies them to the multiplexing processing unit 130.

In the multiplex processing unit 130, each program stream encoded by each of the encoding processing units 100A, 100B, ... And each packetization processing unit 1
Program specification information PSI and contract information EMM packetized by 10, 120 are multiplexed for each transport packet TP to generate a transport stream TS. Then, the transport stream TS
In the ECC encoding unit 140, the error correction code (ECC:
Modulation unit 150 after adding Error Correction Code)
To the transmission system via.

Here, the transport stream T
The packet having the packet identification information PID = "0" of S has a program map table (PMT: Program M) that describes the program configuration for each program number (16 bits).
ap table), which is the packet identification information PID of the transport packet transmitting the ap table, and which has a configuration as shown in FIG.
am Association Table). Further, the program map table PMT has a structure as shown in FIG. 16, and is a packet of a transport packet TP in which an identification number of the program and individual streams such as video signals and audio signals forming the program are transmitted. A list of identification information PID and attached information are described.

In addition, the CA system of the conditional access system is generally constructed as shown in FIG. That is, on the transmission side, when the scramble processing unit 211 of the encoder device 210 scrambles the bit stream based on the scramble key Ks provided by the scramble control device 200 and transmits the scrambled bit stream, the first and second scramble control devices 200 are transmitted. The second encryption processing units 201 and 202 are provided, and the scramble key Ks is
Is encrypted by the first encryption processing unit 201 based on the work key Kw and transmitted, and the work key Kw is transmitted to the master key K by the second encryption processing unit 202.
It is encrypted based on m and transmitted.

Here, the scramble key Ks is as shown in FIG.
As shown in FIG. 8, it is transmitted for each program in ECM packets together with the program information, and is normally updated every few seconds. Further, the work key Kw is transmitted in an EMM packet together with individual information such as contract information as shown in FIG. 19, and has a relatively long cycle (from several hours to several hours).
Will be updated in a few days).

Set top box (STB: Set) on the receiving side
Top Box), the first and second decoding processing units 221 and
In the smart card 220 including 222, the first decryption processing unit 2 using the built-in key Km stored in advance is used.
The work key Kw is decrypted by 21 and the scramble key Ks is decrypted by the second decryption processing unit 222 using this work key Kw. Then, in the IRD, the descramble processing unit 223 descrambles the received bit stream based on the scramble key Ks obtained by the smart card.

Further, in the MPEG2 system, in order to take out the selected program from one transport stream TP in which a plurality of programs are multiplexed, in the set top box STB, the program association table PAT and the program map table PMT are set. , By acquiring the elementary PID, the packet identification information PID of a packet such as a video signal or an audio signal is detected, and the packet corresponding to the packet identification information PID is extracted by the demultiplexer. Also, the ECM data is passed to the smart card to get the scramble key instead. Then, by using the obtained scramble key, the payload part is descrambled, and the descrambled data is decoded to reproduce the video signal and the audio signal.

[0030]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a digital data recording method and recording device for recording a program supplied as a transport stream in the MPEG2 system as described above on a recording medium. is there.

The object of the present invention is also the MPE as described above.
It is an object of the present invention to provide a digital data recording method, a recording device, and a reproducing system that can be easily decoded and reproduced in a set top box STB in a G2 system.

Further, an object of the present invention is to record digital data so that a program selected from one transport stream in which a plurality of programs are multiplexed can be easily recorded and reproduced through a recording medium, It is to provide a recording device and a reproduction system.

[0033]

SUMMARY OF THE INVENTION A digital data recording method according to the present invention comprises a main packet in which main data is compressed and packetized, and auxiliary data necessary for decoding and reproducing the main data from the main packet. When recording a data packet in which a sub packet obtained by packetizing the sub packet is multiplexed on a recording medium, the auxiliary data obtained from the sub packet is recorded together with the data of the main packet.

In the digital data recording method according to the present invention, the main packet is a packet including an elementary stream described in a program map table, a packet including a program clock reference, and a packet including an elementary control message stream. Yes, the sub-packet is a packet including a program association table and a packet including a program map table.

The digital data recording method according to the present invention is characterized in that the program map table packet identification information is used as auxiliary data.

Further, in the digital data recording method according to the present invention, each elementary stream packet identification information,
The program clock reference packet identification information and the elementary control message stream packet identification information are used as auxiliary data.

Further, in the digital data recording method according to the present invention, when recording a data packet in which each main packet and each sub packet of a plurality of programs is multiplexed on a recording medium, the program number is used as auxiliary data. It is characterized by

Furthermore, in the method of recording digital data according to the present invention, when recording a data packet in which each main packet and each sub packet of a plurality of programs is multiplexed on a recording medium, each elementary stream packet identification information is recorded. , Program clock reference packet identification information, elementary control message stream packet identification information, and program number as auxiliary data.

The digital data recording apparatus according to the present invention comprises a main packet in which main data is compressed and packetized, and a sub-packet in which auxiliary data necessary for decoding / reproducing the main data is packetized. Packet separating means for separating the main packet and sub-packet from the multiplexed data packet, auxiliary data extracting means for extracting auxiliary data from the sub-packet separated by this packet separating means, and extraction by this auxiliary data extracting means The recorded auxiliary data is recorded on a recording medium together with the data of the main packet.

In the digital data recording apparatus according to the present invention, the main packet is a packet including an elementary stream described in a program map table, a packet including a program clock reference, and a packet including an elementary control message stream. The sub packet is a packet including a program association table and a packet including a program map table.

The digital data recording apparatus according to the present invention is characterized in that the auxiliary data extracting means supplies the program map table packet identification information to the recording means as auxiliary data.

Further, in the digital data recording apparatus according to the present invention, the auxiliary data extracting means uses the respective elementary stream packet identification information, the program clock reference packet identification information, and the elementary control message stream packet identification information as auxiliary data. It is characterized in that it is supplied to a recording means.

Further, in the digital data recording apparatus according to the present invention, when recording a data packet in which each main packet and each sub packet of a plurality of programs is multiplexed on the recording medium, the auxiliary data extracting means is a program. The number is supplied to the recording means as auxiliary data.

Further, in the digital data recording apparatus according to the present invention, the auxiliary data extracting means is used to record the data packet, in which the main packet and the sub packet of the plurality of programs are multiplexed, on the recording medium. The elementary stream packet identification information, the program clock reference packet identification information, the elementary control message stream packet identification information, and the program number are supplied to the recording means as auxiliary data.

In the digital data reproducing system according to the present invention, a main packet obtained by compressing main data into a packet and a sub packet obtained by packetizing auxiliary data necessary for decoding and reproducing the main data from the main packet are described. Is a digital data reproducing system for reproducing the main data from a recording medium in which auxiliary data obtained from subpackets of a data packet in which are multiplexed together with the data of the main packet are recorded. A reproducing means for reproducing the data together with the data of the main packet, and a decoding / reproducing means for decoding / reproducing the main data from the data of the main packet reproduced by the reproducing means based on the auxiliary data
Reproduction processing means is provided.

In the digital data reproducing system according to the present invention, the main packet is a packet including an elementary stream described in a program map table, a packet including a program clock reference, and a packet including an elementary control message stream. The sub packet is a packet including a program association table and a packet including a program map table.

Further, in the digital data reproducing system according to the present invention, the reproducing means reproduces the program map table packet identification information from the recording medium as auxiliary data together with the main packet data.

Further, in the digital data reproducing system according to the present invention, the reproducing means stores auxiliary data from the recording medium for each elementary stream packet identification information, program clock reference packet identification information and elementary control message stream packet identification information. Is reproduced with the data of the main packet.

Further, in the digital data reproducing system according to the present invention, the reproducing means reproduces the data packet in which the main packet and the sub packet of the plurality of programs are multiplexed from the recording medium. , The program number as auxiliary data is reproduced together with the data of each main packet.

Further, in the digital data reproducing system according to the present invention, the reproducing means reproduces the data packet in which the main packets and the sub packets of the plurality of programs are multiplexed from the recording medium. It is characterized in that each elementary stream packet identification information, program clock reference packet identification information, elementary control message stream packet identification information and program number are reproduced from the recording medium as auxiliary data together with the data of each main packet.

[0051]

In the digital data recording method according to the present invention,
A data packet in which a main packet obtained by compressing the main data into a packet and a sub packet obtained by packetizing auxiliary data necessary for decoding and reproducing the main data from the main packet are multiplexed are recorded on a recording medium. At this time, the auxiliary data obtained from the sub packet is recorded together with the data of the main packet.

Here, the main packet is, for example, a packet including an elementary stream described in a program map table, a packet including a program clock reference, and a packet including an elementary control message stream, and the sub packet is a program. It is a packet including an association table and a packet including a program map table.

Further, in the digital data recording method according to the present invention, for example, the program map table packet identification information is used as auxiliary data. Further, for example, each elementary stream packet identification information, program clock reference packet identification information, and elementary control message stream packet identification information are used as auxiliary data. Also, when recording a data packet in which each main packet and each sub packet of a plurality of programs is multiplexed on a recording medium, the program number is used as auxiliary data. Furthermore, when recording a data packet in which each main packet and each sub packet of a plurality of programs is multiplexed on a recording medium, each elementary stream packet identification information, program clock reference packet identification information, elementary control message stream packet The identification information and program number are used as auxiliary data.

In the digital data recording apparatus according to the present invention, a main packet in which the main data is data-compressed and packetized and a sub-packet in which auxiliary data necessary for decoding / reproducing the main data are packetized are packetized. The main packet and the sub-packet are separated from the multiplexed data packet by the packet separating means, the auxiliary data is extracted from the sub-packet separated by the packet separating means, and the auxiliary data is extracted by the auxiliary data extracting means. It is recorded on the recording medium together with the data of the main packet.

In the digital data recording apparatus according to the present invention, the main packet includes, for example, a packet including an elementary stream described in a program map table, a packet including a program clock reference, and an elementary control message stream. The sub-packet is a packet including a program association table and a packet including a program map table.

In the digital data recording apparatus according to the present invention, the auxiliary data extraction means supplies the program map table packet identification information as auxiliary data to the recording means. Further, the auxiliary data extracting means supplies, for example, each elementary stream packet identification information, program clock reference packet identification information, and elementary control message stream packet identification information to the recording means as auxiliary data. Further, the auxiliary data extracting means supplies a program number, for example, as auxiliary data to the recording means when recording a data packet in which each main packet and each sub packet of a plurality of programs are multiplexed on the recording medium. Further, the auxiliary data extracting means supplies, for example, each elementary stream packet identification information, program clock reference packet identification information, elementary control message stream packet identification information and program number to the recording means as auxiliary data.

In the digital data reproducing system according to the present invention, a main packet obtained by compressing main data into a packet and a sub packet obtained by packetizing auxiliary data necessary for decoding / reproducing the main data from the main packet. From the recording medium in which the auxiliary data obtained from the subpacket of the data packet in which the and are multiplexed are recorded together with the data of the main packet, the above-mentioned auxiliary data is reproduced together with the data of the main packet by the reproducing means, and this reproducing means The decoding / reproduction processing means decodes / reproduces the main data from the reproduced main packet data based on the auxiliary data.

In the digital data reproducing system according to the present invention, the main packet is a packet including an elementary stream described in the program map table, a packet including a program clock reference, and a packet including an elementary control message stream. The sub-packet is a packet including a program association table and a packet including a program map table.

The reproducing means reproduces the program map table packet identification information from the recording medium as auxiliary data together with the main packet data. Further, the reproduction means reproduces, for example, each elementary stream packet identification information, program clock reference packet identification information, and elementary control message stream packet identification information from the recording medium as auxiliary data together with the data of the main packet.

In the digital data reproducing system according to the present invention, the reproducing means reproduces the data packet, in which the main packets and the sub packets of the plurality of programs are multiplexed, from the recording medium. , The program number is used as auxiliary data together with the data of each main packet. Further, the reproducing means is, for example, each elementary stream packet identification information from the recording medium,
The program clock reference packet identification information, the elementary control message stream packet identification information, and the program number are reproduced as auxiliary data together with the data of each main packet.

[0061]

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

FIG. 1 shows a digital VT to which the present invention is applied.
It is a block diagram which shows the structure of the video recording / reproducing system using R.

This video recording / reproducing system is based on MPEG.
Digital broadcasting that adopts two systems, such as ATV (Advanced
For receiving and recording an ATV signal, converting a desired program into a standard television signal, and outputting the same. The recording and reproducing unit 20 records and reproduces the received scrambled broadcast bit stream.

The receiving section 10 includes a front end 11 for receiving an ATV signal and a front end 11 for receiving the broadcast.
The transport stream of the ATV signal received by and the transport stream of the playback signal of the recording / playback unit 20 are selectively supplied to the demultiplexer (DMUX: Demutiplexer) 13 and connected to the DMUX 13. The control section 14 and the scramble processing section 15 and the output of the descramble processing section 15 are supplied through the video / audio decoder 16 to an NTCS (National Television Systems Committee).
/ PAL (Phase Alternation by Line) encoder 17
And so on.

The DMUX 13 is a transport stream (TS: Trans) supplied through the selection circuit 12.
port Stream) to each transport packet (TP: Transp
ortPacket), which is the packet identification information (PID: Packet Identifucati) supplied from the control unit 14.
The transport packet TP corresponding to (on) is separated from the transport stream TS and sequentially supplied to the descramble processing unit 15.

The control unit 14 includes a filter unit 14A and
PAT analysis unit 14B connected to this filter unit 14A
And a PMT analysis unit 14C.

In the control unit 14, the filter unit 14A extracts the program association table PAT from the transport packet TP supplied via the DMUX 13. Then, the PAT analysis unit 14B analyzes the program association table PAT to detect the program map table packet identification information (PMT_PID: Program Map Table PID). Further, the filter unit 14A is provided with the DMUX1.
3 from the transport packet TP supplied via the program map table packet identification information P
Program map table (PM based on MT_PID
T: Program Map Table). And the above PM
The T analysis unit 14C uses the program map table PM.
The T is analyzed to detect the elementary PID of each packet such as a video signal or an audio signal of a desired program, and the elementary PID is supplied to the DMUX 13.

The descramble processing section 15 determines whether the transport packet TP of a desired program is E
The CM data is passed to a smart card (not shown), the scramble key is obtained instead, and the payload is descrambled. Then, the video / audio decoder 1
Reference numeral 6 reproduces a video signal and an audio signal by decoding the data descrambled by the descramble processing unit 15. Furthermore, the above NTCS / P
The AL encoder 17 converts the video signal and the audio signal reproduced by the video / audio decoder 16 into a television signal of the NTCS system or the PAL system and supplies it to a monitor device (not shown).

Further, in the video recording / reproducing system of this embodiment, the recording / reproducing section 2 connected to the receiving section 10 is used.
0 is provided with a recording system having a structure as shown in FIG. 2, for example.

The recording system shown in FIG. 2 has an input terminal 2 for a video signal of the current television system such as the NTSC system.
1 is provided. That is, when recording a television signal from the outside, the component video signal is supplied to the input terminal 21. The component video signal from the input terminal 21 is supplied to the A / D converter 22 and
The converter 22 converts the component video signal into a digital signal and supplies the digital signal to the DCT compression circuit 23.

The DCT compression circuit 23 compresses the input video signal by DCT conversion and variable length coding. That is, the component video signal from the A / D converter 22 is blocked, shuffled, and DCT.
The conversion is done. The DCT-converted data is buffered in a predetermined buffer unit. The code in this predetermined buffer unit is estimated, a quantization table is determined so that the total code amount is equal to or less than a predetermined value, and quantization is performed using this optimum quantization table. Then, it is variable length coded and framed.

Further, this recording system is a switch circuit which is switched between recording the MPEG2 transport packet TP supplied from the DMUX 13 of the receiving unit 10 and recording the video signal from the input terminal 21. 24 are provided. The terminal 24 of this switch circuit 24
A transport packet TP of MPEG2 is supplied to A via the rate conversion and format conversion unit 29.

Rate conversion and format conversion unit 29
Extracts the required program from the MPEG2 transport packet and sets this rate to, for example, 30 Mb.
Convert from ps to 10 Mbps. Furthermore, as described later, in order to obtain good image quality during variable speed reproduction,
Place the data in the trick play area. The output of the DCT compression circuit 23 is supplied to the terminal 24B of the switch circuit 24. When recording an MPEG2 transport packet, the switch circuit 24 is set on the terminal 24A side. When recording the video signal from the input terminal 21, the switch circuit 24 is set to the terminal 24B side.

The output of the switch circuit 24 is supplied to the framing circuit 25. The framing circuit 25 expands the recording data into a predetermined frame and performs error correction code processing.

The output of the framing circuit 25 is supplied to the channel coder 26 and modulated. The output of the channel coder 26 is sent to the rotary head 28 via a recording amplifier 27.
The rotary head 28 records the compressed video signal or transport packet on the magnetic tape.

In such a recording system, when recording an MPEG2 transport packet, the switch circuit 24 is switched to the terminal 24A side. For this reason,
The MPEG2 transport packet input through the rate conversion and format conversion unit 29 is framed by the framing circuit 25, modulated by the channel coder 26, and recorded on the magnetic tape by the rotary head 28.

When recording the video signal from the input terminal 21, the switch circuit 24 is switched to the terminal 4B side. Therefore, the video signal from the input terminal 21 is DC
It is compressed by a T circuit 23, framed by a framing circuit 25, modulated by a channel coder 26, and recorded on a magnetic tape by a rotary head 28.

Here, at the time of recording an ATV system signal,
In the interface and format conversion unit 29, in order to improve the image quality during variable speed reproduction, a reproducible area (hereinafter referred to as an area) during variable speed reproduction is set as a trick play area TP as shown in FIG. The data is arranged so that the I picture data is recorded in the play area as data for variable speed reproduction (hereinafter referred to as trick play data). During variable speed reproduction, I picture data is read from the trick play area TP and decoded.

That is, FIG. 3 is a diagram showing the locus of the A head of two heads (hereinafter, referred to as A head and B head) having different azimuths, for example, during variable speed reproduction. When the A head traces as shown in FIG.
The area indicated by is the reproducible area. This reproducible area is used as a trick play area TP for recording data for variable speed reproduction. In the VTR of helical scan and azimuth recording, the data reproduced from the trick play area TP has a burst shape as shown in FIG. If the position of the trick play area TP on the track is fixed by ATF or the like and trick play data, that is, data for variable speed reproduction is recorded in the trick play area TP, this data is surely reproduced.

Further, FIG. 5 is a diagram showing the structure of one track in the recording / reproducing section 20.

One track is an audio sector SEC1.
, Video sector SEC2, subcode sector SEC
And 3. In the video sector SEC2, FIG.
As shown in, the capacity of video data for 135 sync blocks is prepared. 5 at the beginning of each sync block
A byte sync and ID are added. To these video data, auxiliary data (VAU
X) is added. Further, the error correction code (C1, C2) is doubly added using the product code.

Thus, one track of the video sector S
Video data for 135 sync blocks can be recorded in the EC2. In the SD mode, the rotation speed of the drum is 150 Hz, two heads having different azimuths are arranged on the rotating drum, and data is recorded in 10 tracks per frame. Then, as shown in FIG. 7, when recording an ATV system signal (hereinafter referred to as an ATV signal), if 75 bytes of the 77 bytes of the data area in one sync block are used for data recording, 77 × 8 × 135 × 10 × 30 = 24.948 [Mbp
s] is the data rate that can be used for recording.

On the other hand, the data rate of the ATV signal is about 1
It is 9.2 Mbps. Therefore, the transmitted A
When recording a TV signal in the SD ^{mode, 19.2 × 10 6/300/} 77/8 = 104 sync blocks as a recording area for normal reproduction, are used to record the total bitstream. The remaining 135-104 = 31 sync blocks can be used as the trick play area TP. Therefore, in order to improve the image quality during variable speed reproduction, when the ATV signal is recorded in the SD mode, I picture data is recorded as data necessary for variable speed reproduction.
Then, in this embodiment, the data of the I picture to be recorded in this spare recording area is, for example, all the low frequency coefficient data for one picture. As a result, during variable speed reproduction,
Can be updated in screen units.

FIG. 8 is a block diagram showing the structure of the reproducing system of the recording / reproducing unit 20. In the reproducing system shown in FIG. 8, the recording signal of the magnetic tape is reproduced by the rotary head 31 and supplied to the channel decoder 33 via the reproducing amplifier 32. The channel decoder 33 demodulates a reproduction signal by a demodulation method corresponding to the modulation method of the recording channel encoder 26 described above.

The output of the channel decoder 33 is supplied to a time base correction processing unit (TBC: Time Base Corrector) 34. The TBC 34 is for removing the time axis fluctuation component in the reproduced signal, and is supplied with a write clock based on the reproduced signal and a read clock based on the reference signal, and is also supplied with the output of the channel decoder 52. There is.

Then, the TBC 34 supplies the reproduction signal from which the time-axis fluctuation component is removed to the deframe conversion circuit 35.
The deframing circuit 35 corresponds to the framing circuit 25 of the recording system, and performs error correction processing of the reproduced data from the TBC 35.

This reproducing system is provided with a switch circuit 36 which can be switched between reproducing an ATV system signal and reproducing a component video signal. The output of the deframe circuit 35 is supplied to the switch circuit 36. When the reproduction signal is an ATV system signal, the switch circuit 3
6 is switched to the terminal 36A side. When the reproduced signal is a component video signal, the switch circuit 36 is switched to the terminal 36B side.

The DCT expansion circuit 37 in which the switch circuit 36 is connected to the terminal 36B corresponds to the DCT compression circuit 23 of the recording system. That is, the DCT expansion circuit 56
Decodes the variable-length code that is the reproduction data and performs inverse DCT conversion to expand the compressed and recorded component video signal to the original baseband video signal. That is, the DCT expansion circuit 37
The output of the terminal 36B of the switch circuit 36 is supplied to the DC
The T decompression circuit 37 restores the reproduced data to a baseband video signal, and this video signal is output from the output terminal 38.

The output of the terminal 36A of the switch circuit 36 is supplied to the packet selecting section 39. And A
When the TV system signal is normally reproduced, the packet selection unit 39
Selects all the packets of the reproduction data supplied via the switch circuit 36. On the other hand, during variable speed reproduction, the packet selection unit 39 selects and outputs an I picture packet obtained by reproducing the trick play area TP. The output of the packet selector 39 is output from the output terminal 40.

The controller 41 performs control for switching between normal reproduction and variable speed reproduction. A mode setting signal is supplied to the controller 41 from the input unit 42. The servo circuit 43 and the packet selector 49 are controlled according to the mode setting signal. Then, at the time of variable speed reproduction of the ATV system signal, tracking is performed by the servo circuit 43 by feeding back a tracking error signal detected based on the ATF signal at the time of normal reproduction to the phase loop of the capstan servo. During playback,
By returning the phase error signal detected based on the last sync block number obtained from the reproduction data for each trace to the phase loop of the capstan servo, the positional relationship between the head trace and the track is always kept the same. , The phase is fixed so that the head traces the trick play area TP in the track. As a result, during variable speed reproduction, the trick play area is reproduced, and the I picture data recorded in the trick play area TP is reproduced.

Here, in the recording / reproducing unit 20 having such a recording system and a reproducing system, the data necessary for recording / reproducing one program of the ATV signal is the elementary stream described in the program map table PMT. Including a program clock reference PCR, a packet including a program clock reference PCR, a packet including a program association table PAT, a packet including a program map table PMT, a video ES_PID, and an audio E.
These are S_PID, data ES_PID, program clock reference packet identification information PCR_PID, elementary control message stream packet identification information ECM_PID, and the like.

In the recording / reproducing unit 20 of this embodiment, in the above recording system, for example, a packet including a video elementary stream, a packet including an audio elementary stream, and a packet including a data elementary stream are included in the normal reproduction area of the video sector. , The packet including the program clock reference PCR and the packet including the program map table PMT are recorded, and only the PMT_PID is recorded in the above-mentioned preliminary data (VAU).
X) is recorded (Example 1).

That is, a video elementary stream, an audio elementary stream, a data elementary stream, a program clock reference P
Each packet of the CR and the program map table PMT is a set top box STB, that is, the receiving unit 1 described above.
With respect to the input from 0, a time stamp is applied to each packet and the normal reproduction area of the video sector on the magnetic tape is recorded as it is. Also, set top box S
Program map table packet identification information PMT_PID of the program to be recorded is obtained from TB, and this is recorded as preliminary data (VAUX).

Then, in the reproducing system, each packet reproduced from the normal reproducing area of the video sector on the magnetic tape, that is, the packet including the video elementary stream,
A packet including an audio elementary stream, a packet including a data elementary stream, a packet including a program clock reference PCR, and a packet including a program map table PMT are selected by the receiving unit 10 on the basis of a time stamp recorded at the time of recording. It is supplied to the DMUX 13 via the circuit 12. Further, the program map table packet identification information PMT_PID recorded as the preliminary data (VAUX) is reproduced and supplied to the controller 14 of the receiver 10.

As a result, the control unit 14 of the receiving unit 10
Then, the recording / reproducing unit 2 supplied to the DMUX 13
Based on the PMT_PID supplied from the recording / reproducing unit 20 from the output stream s of 0, the filter unit 1
The program map table PMT is taken out at 4A. And this program association table PAT
Is analyzed by the PAT analysis unit 14B to acquire the program map table packet identification information PMT.

Therefore, in the receiving section 10, the DMU is
Based on the contents of the program map table PMT analyzed by the PAT analysis unit 14B of the control unit 14 from the output stream s of the recording / reproduction unit 20 supplied to the X13, a packet including a video elementary stream, an audio elementary stream. Separate the packet containing the stream and the packet containing the data elementary stream,
Decoding / playback processing can be performed.

Further, in the recording / reproducing section 20 of this embodiment,
In the above recording system, in the normal playback area of the video sector, for example, a packet including a video elementary stream, a packet including an audio elementary stream, a packet including a data elementary stream, and a packet including a program clock reference PCR are recorded, The video ES_PID, the audio ES_PID, the data ES_PID, the program clock reference packet identification information PCR_PID, and the elementary control message stream packet identification information ECM_PID are the above-mentioned auxiliary data (VAUX).
May be recorded as (Example 2).

That is, each packet of the video elementary stream, the audio elementary stream, the data elementary stream and the program clock reference PCR is time stamped for each packet to the input from the set top box STB, It is recorded in the normal playback area of the video sector on the magnetic tape as it is. Also, set top box STB
Further, the program map table packet identification information PMT_PID of the program to be recorded is obtained, the program map table PMT is obtained based on this program map table packet identification information PMT_PID, and the video ES_PID, audio ES_PID, and data ES_PID of the packet to be recorded from the contents. , The program clock reference packet identification information PCR_PID and the elementary control message stream packet identification information ECM_PID are detected, and a time stamp is added thereto and recorded as the preliminary data (VAUX). The value of the stream type and the packet identification information PID can be obtained directly from the set top box STB.

In the reproducing system, each packet reproduced from the normal reproducing area of the video sector on the magnetic tape, that is, the packet containing the video elementary stream,
The packet containing the audio elementary stream, the packet containing the data elementary stream, and the packet containing the program clock reference PCR are supplied to the set top box STB based on the time stamp that was recorded. In addition, the preliminary data (VA
Each stream type and packet identification information PID recorded as UX) is reproduced and supplied to the set top box STB.

As a result, in the receiving unit 10, that is, the set top box STB, the preliminary data (VAU
X) is reproduced, and each of the stream types and the packet identification information PID are obtained. From the output stream of the recording / reproducing unit 20, a packet including a video elementary stream, a packet including an audio elementary stream, and a data elementary A packet including a stream can be separated for decoding / reproduction processing.

Further, in the recording / reproducing unit 20 of this embodiment, in the above recording system, for example, a packet including a video elementary stream, a packet including an audio elementary stream, and a data elementary stream are recorded in the normal reproducing area of the video sector. Packet containing, packet containing program clock reference PCR,
The program map table PMT and the program association table PAT may be recorded, and the program number may be recorded as the preliminary data (VAUX) (Example 3).

In the reproducing system, each packet reproduced from the normal reproducing area of the video sector on the magnetic tape, that is, the packet containing the video elementary stream,
The packet containing the audio elementary stream, the packet containing the data elementary stream, and the packet containing the program clock reference PCR are supplied to the set top box STB based on the time stamp that was recorded. In addition, the preliminary data (VA
The program number recorded as UX) is reproduced and supplied to the set top box STB.

As a result, in the receiving unit 10, that is, the set top box STB, the program association table PAT is acquired from the output stream of the recording / reproducing unit 20, and the program number obtained by reproducing the preliminary data (VAUX) is set. On the basis of the above, the program map table packet identification information PMT_PID is obtained from the program association table PAT, and a packet including a video elementary stream, a packet including an audio elementary stream, and a packet including a data elementary stream are separated according to the contents thereof. , Decryption / playback processing can be performed.

In this case, in the case of recording a part of the plurality of programs described in the program association table PAT, excluding the programs, excluding the programs, the information of the programs not recorded from the program association table PAT is deleted. By recording the data in advance, unnecessary data is not recorded or reproduced.

Further, in the recording / reproducing section 20 of this embodiment, the recording methods described in the above-mentioned Examples 1, 2 and 3 may be combined. For example, in the above recording system,
In the normal playback area of the video sector, for example, a packet containing a video elementary stream, a packet containing an audio elementary stream, a packet containing a data elementary stream, a packet containing a program clock reference PCR, a program map table PMT, and a program association table PAT.
Record the program number, video ES_P
ID, audio ES_PID, data ES_PID,
Program clock reference packet identification information PC
The R_PID is recorded as the preliminary data (VAUX) (Example 4).

Here, the PMT_PID is, for example, 1 of b0 to b12 in the packet structure as shown in FIG.
It is given in 3 bits and recorded as the above-mentioned preliminary data (VAUX). The program number is given as 16 bits b0 to b15 in the packet structure as shown in FIG. 10, and is recorded as the spare data (VAUX). Further, the stream type and the packet identification information PID are given the stream type by 8 bits b0 to b7 in the packet structure as shown in FIG. 11, and the packet identification information PID by 13 bits b0 to b12. And is recorded as the preliminary data (VAUX).

[0107]

As described above, according to the present invention, a main packet obtained by compressing main data into a packet and a sub packet obtained by packetizing auxiliary data necessary for decoding / reproducing the main data from the main packet. When recording the data packet in which and are multiplexed on the recording medium, the auxiliary data obtained from the sub packet is recorded together with the data of the main packet. As a result, main data can be easily decoded / reproduced from the main packet by using the auxiliary data in a set-top box in a reproducing system such as an MPEG2 system.

Further, in the present invention, when recording a data packet in which each main packet and each sub packet of a plurality of programs are multiplexed on a recording medium, the program number is recorded as auxiliary data together with the data of the main packet. This makes it possible to easily record and reproduce a program selected from one transport stream in which a plurality of programs are multiplexed in a reproduction system, for example, an MPEG2 system, via a recording medium.

[Brief description of drawings]

FIG. 1 is a block circuit diagram showing a configuration of a digital data recording / reproducing system to which the present invention is applied.

FIG. 2 is a block diagram showing a configuration of a recording system of a recording / reproducing unit in the digital data recording / reproducing system.

FIG. 3 is a diagram showing a scanning state of a rotary head during variable speed reproduction by the recording / reproducing unit.

FIG. 4 is a diagram showing a reproduction waveform during variable speed reproduction by the recording / reproducing unit.

FIG. 5 is a diagram showing a configuration of tracks on a magnetic tape formed by the recording / reproducing unit.

FIG. 6 is a diagram showing a structure of a video sector of data to be recorded on a magnetic tape by the recording / reproducing unit.

FIG. 7 is a diagram showing a structure of a sync block of data to be recorded on a magnetic tape by the recording / reproducing unit.

FIG. 8 is a block diagram showing a configuration of a reproducing system of a recording / reproducing unit in the digital data recording / reproducing system.

FIG. 9 is a diagram showing a packet structure of program map table packet identification information PMT_PID recorded on a magnetic tape as auxiliary data recorded by the recording / reproducing unit.

FIG. 10 is a diagram showing a packet structure of program numbers to be recorded on a magnetic tape as auxiliary data to be recorded by the recording / reproducing unit.

FIG. 11 is a diagram showing a packet structure of a stream type and packet identification information PID recorded on a magnetic tape as auxiliary data recorded by the recording / reproducing unit.

FIG. 12 is a block diagram showing a configuration of an ATV system transmission system adopting the MPEG2 system.

FIG. 13 is a diagram showing the structure of a PES packet in the MPEG2 system.

FIG. 14 is a diagram showing a structure of a transport packet TP in the MPEG2 system.

FIG. 15 is a diagram showing the structure of a program association table PAT in the MPEG2 system.

FIG. 16 is a diagram showing a structure of a program map table PMT in the MPEG2 system.

FIG. 17 is a block diagram showing a configuration of a conditional access system CA system.

FIG. 18 is a diagram showing the contents of program information transmitted in an ECM packet.

FIG. 19 is a diagram showing the content of individual information transmitted in an EMM packet.

[Explanation of symbols]

 10 reception unit 13 demultiplexer 14 control unit 15 scramble processing unit 20 recording / playback unit 29 rate conversion and format conversion unit 39 packet selection unit

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Claims (18)

[Claims] 1. A data packet in which a main packet obtained by compressing main data into a packet and a sub packet obtained by packetizing auxiliary data necessary for decoding and reproducing the main data from the main packet are multiplexed. A method for recording digital data, characterized in that auxiliary data obtained from the sub-packet is recorded together with the data of the main packet when recording on the recording medium. 2. The main packet is a packet including an elementary stream described in a program map table, a packet including a program clock reference, and a packet including an elementary control message stream, and the sub packet includes a program association table. 2. The method for recording digital data according to claim 1, wherein the packet is a packet including the packet and a packet including a program map table. 3. The method for recording digital data according to claim 2, wherein the program map table packet identification information is used as auxiliary data. 4. The method for recording digital data according to claim 2, wherein each elementary stream packet identification information, program clock reference packet identification information, and elementary control message stream packet identification information is used as auxiliary data. 5. A digital program according to claim 2, wherein a program number is used as auxiliary data when a data packet in which each main packet and each sub packet of a plurality of programs are multiplexed is recorded on a recording medium. How to record data. 6. An elementary stream packet identification information, a program clock reference packet identification information, and an elementary control when recording a data packet in which each main packet and each sub packet of a plurality of programs are multiplexed on a recording medium. The method for recording digital data according to claim 2, wherein the message stream packet identification information and the program number are used as auxiliary data. 7. A data packet in which a main packet obtained by compressing main data into a packet and a sub packet obtained by packetizing auxiliary data necessary for decoding / reproducing the main data from the main packet are multiplexed into the main packet. Packet separation means for separating the packet and sub-packet, auxiliary data extraction means for extracting auxiliary data from the sub-packet separated by the packet separation means, and auxiliary data extracted by this auxiliary data extraction means for the main packet data A recording device for digital data, which records on a recording medium together with the recording medium. 8. The main packet is a packet including an elementary stream described in a program map table, a packet including a program clock reference, and a packet including an elementary control message stream, and the sub-packet includes a program association table. The digital data recording device according to claim 7, wherein the packet is a packet including the packet and a packet including a program map table. 9. The digital data recording apparatus according to claim 8, wherein the auxiliary data extracting means supplies the program map table packet identification information as auxiliary data to the recording means. 10. The auxiliary data extraction means supplies each elementary stream packet identification information, program clock reference packet identification information and elementary control message stream packet identification information to the recording means as auxiliary data. The digital data recording device according to claim 8. 11. When recording a data packet in which each main packet and each sub-packet of a plurality of programs is multiplexed on a recording medium, the auxiliary data extracting means supplies a program number to the recording means as auxiliary data. 9. The digital data recording apparatus according to claim 8, wherein: 12. When recording a data packet in which each main packet and each sub-packet of a plurality of programs is multiplexed on a recording medium, the auxiliary data extracting means includes each elementary stream packet identification information and program clock reference. 9. The digital data recording apparatus according to claim 8, wherein the packet identification information, the elementary control message stream packet identification information, and the program number are supplied to the recording means as auxiliary data. 13. A main packet obtained by compressing main data into a packet and decoding the main data from the main packet.
Reproduction of the main data from a recording medium in which auxiliary data obtained from a subpacket of a data packet in which a subpacket of packetized auxiliary data necessary for reproduction is multiplexed together with data of the main packet are recorded. A reproducing system for digital data, comprising reproducing means for reproducing the auxiliary data together with main packet data from a recording medium, and decoding main data based on the auxiliary data from main packet data reproduced by the reproducing means. A reproducing system for digital data, comprising a decoding / reproducing processing means for reproducing. 14. The main packet is a packet including an elementary stream described in a program map table, a packet including a program clock reference, and a packet including an elementary control message stream, and the sub-packet includes a program association table. 14. The digital data reproducing system according to claim 13, wherein the packet is a packet including the packet and a packet including a program map table. 15. The digital data reproducing system according to claim 14, wherein the reproducing means reproduces the program map table packet identification information from the recording medium as auxiliary data together with the main packet data. 16. The reproducing means reproduces each elementary stream packet identification information, program clock reference packet identification information and elementary control message stream packet identification information from a recording medium as auxiliary data together with main packet data. The digital data reproducing system according to claim 14. 17. The reproducing means reproduces, from the recording medium, a data packet in which main packets and sub-packets of a plurality of programs are multiplexed from the recording medium.
15. The digital data reproducing system according to claim 14, wherein the program number is reproduced together with the data of each main packet as auxiliary data. 18. The reproducing means reproduces, from the recording medium, a data packet in which main packets and sub packets of a plurality of programs are multiplexed from the recording medium.
15. The recording medium reproduces each elementary stream packet identification information, program clock reference packet identification information, elementary control message stream packet identification information, and program number as auxiliary data together with data of each main packet. Digital data playback system.