JPH08340541A - Transmission method, transmitter, recording method, recorder, reproduction method, reproduction device, recording reproduction method and recording/ reproduction device for digital data - Google Patents

Abstract

PURPOSE: To attain variable speed reproduction of a program subjected to scramble processing by eliminating the mixture of I picture data, P picture data and B picture data in a transport packet. CONSTITUTION: A PES packet of a program A subject to PES packet processing in the unit of variable length by a multiplexer processing section 103A in a coding processing section 100A is fed to a multiplexer processing section 105A via a scramble processing section 104A, in which the packet is processed into a fixed length TP packet and the TP is multiplexed to form a stream of the program A. Furthermore, a coding processing section 100B conducts almost the similar processing to that by the processing section 100A to generate a stream of a program B. The processing sections 100A, 100B apply packet processing to I picture data, B picture data and P picture data into individual PES packets in the case of packet-processing of a video signal to the PES packet to process the PES packet into the fixed length TP packet and the TP is multiplexed into a TP stream.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION This invention is based on the MPEG (Moving P
icture Experts Group) Digital data transmission method, transmission device, recording method for recording / reproducing 2 types of transport packets via a recording medium such as a magnetic tape,
The present invention relates to a recording device, a reproducing method, a reproducing device, a recording / reproducing method, and a recording / reproducing device.

[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, is used. Development is in progress. In such a digital VTR,
A mode for recording video signals of the current television system such as NTSC system (hereinafter referred to as SD mode) and a so-called high-definition television system video signal (hereinafter, HD: Hi)
gh Definition Television signal. ) Recording mode (hereinafter referred to as HD mode) can be set. In the SD mode, the video signal is compressed and recorded in a digital video signal of about 25 Mbps, and in the HD mode, the HDTV signal is compressed and recorded in a digital video signal of about 50 Mbps.

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, an input digital video signal is once decoded to reproduce, for example, an HDTV signal, and the HDTV signal is again reproduced to a predetermined value. There is an advantage that it is not necessary to re-encode by the encoding method and record it on the magnetic tape, and waste of hardware is eliminated.

By using such a digital VTR, WG (Working Group) 11 of SC (Sub Committee) in JTC (Joint Technical Committee) 1 of International Standards Organization (so-called ISO) and International Electrotechnical Commission (so-called IEC) is used.
Which is a moving picture coding method standardized in MPEG
Recording of two Transport Packets is under consideration.

That is, the MPEG2 is provided with a multi-program support function that enables transmission of a plurality of programs. In this method, individual coded streams are time division multiplexed in relatively short units called transport packets. The transport packet is
It has a fixed length of 188 bytes, and its header part contains
Since there is format-specific information without packet data, the packet required for the intended program reproduction is selected and decoded.

FIG. 25 shows the structure of a transport packet. As shown in FIG. 25, a header is provided at the beginning of the transport packet, and a payload (information) is provided therein. The header has an 8-byte sync, a transport error indicator indicating whether or not there is an error in the packet, a payload unit start indicator indicating the start of the payload unit,
Transport priority that indicates the importance of the packet, packet identification information (PID: Packet Identifucation) that indicates the attributes of individual packets of the packet, whether or not the payload is scrambled, transport scramble control that indicates the type, and whether or not there is an adaptation field. Adaptation field control that indicates, a cyclic counter for detecting whether or not a packet has been discarded halfway, and an adaptation field that can store additional information and stuffing bytes regarding an individual stream.

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. .

When recording such an MPEG2 transport packet in a digital VTR, as shown in FIG. 26, a desired program (from the programs A, B and C transmitted in time division multiplexed form) is transmitted. For example, program A) is selected. At this time, if the data rate of the multi-program is, for example, 30 Mbps and the actual rate of the selected program is 10 Mbps, the rate conversion buffer performs rate conversion from 30 Mbps to 10 Mbps.

That is, the transport packet of the selected program is the rate conversion buffer and the rate is 1.
It can be lowered to / 3. This gives a rate of 30 Mbps
To 10 Mbps. This rate-converted transport packet is recorded by the digital VTR.

Since the recording rate of the SD mode of the digital VTR is 25 Mbps, if the rate conversion is performed in this way,
The transport packet can be recorded on the digital VTR as it is.

Further, generally, a conditional access system CA system is configured as shown in FIG. That is, on the transmission side, when the scramble processing unit 111 of the encoder device 110 scrambles the bit stream based on the scramble key Ks provided by the scramble control device 120 and transmits the scrambled bit stream, the first and second scramble control devices 120 are transmitted. The second encryption processing units 121 and 122 are provided, and the scramble key Ks is
Is encrypted by the first encryption processing unit 121 based on the work key Kw and transmitted, and the work key Kw is transmitted by the second encryption processing unit 122 to the master key Kw.
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, as shown in FIG. 29, the work key Kw is transmitted in an EMM packet together with individual information such as contract information, and has a relatively long cycle (from several hours to several hours).
Will be updated in a few days).

A set top box (STB: Set) on the receiving side
In the Top Box), in the smart card including the first and second decryption processing units, the work key Kw is decrypted by the first decryption processing unit using the built-in key Km that is built in advance, and the work key Kw is decrypted. The second decryption processing unit uses Kw to decrypt the scramble key Ks. And IR
In D, the descramble processing unit performs descramble processing on the received bit stream based on the scramble key Ks obtained by the smart card.

Further, in the MPEG2 system, in order to extract a selected program from one transport stream in which a plurality of programs are multiplexed,
In the set top box STB, the packet association information PAT, the program map table PMT, and the elementary PID are acquired to detect the packet identification information PID of a packet such as a video signal or an audio signal, and the packet identification information PID is detected.
The packet corresponding to the ID 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.

In the MPEG2 system, I picture data of an I frame that has been intra-frame coded, P picture data of a P frame that has been forward predictively coded, and B picture data of a B frame that has been bidirectionally predictively coded are transmitted. Has been. During variable speed reproduction, the head goes over the track, so that data of consecutive frames cannot be obtained. If data of consecutive frames cannot be obtained, data of P frame and B frame cannot be decoded. Only the I picture data of the intraframe-encoded I frame can be decoded. Therefore, during variable speed playback,
By recording the I picture data in the trick play area for variable speed reproduction, variable speed reproduction can be performed.

That is, a playable area during variable speed reproduction is defined as a trick play area TP, and data is arranged so that I picture data is recorded in the trick play area as data for variable speed reproduction. During variable speed reproduction, I picture data is read from the trick play area TP and decoded.

[0018]

By the way, when recording / reproducing a scrambled program, in a normal recording / reproducing operation, a scrambled bit stream and an ECM stream corresponding thereto are all recorded together. If so, the time relationship between the scrambled bit stream and the scramble key is maintained as it is, so by sending it back as it is during playback, the set top box S
In TB, it can be descrambled as usual.

However, in the variable speed reproduction, only a part of the bit stream, that is, the data of the I frame is reproduced intermittently, so that the scrambled bit stream and the ECM stream corresponding thereto are all recorded together. If so, the relationship between the scrambled bit stream and the scramble key will change significantly, so
There was a problem that it could not be descrambled normally.

Therefore, an object of the present invention is to enable variable speed reproduction of a scrambled program.

[0021]

SUMMARY OF THE INVENTION A digital data transmission method according to the present invention is a fixed length transport of a packetized elepentary stream packet in which intra-frame coded picture data and predictive coded picture data are packetized. At the time of packetizing into a packet and performing the scrambling process on the payload part of the packet for transmission, at least the intra-frame coded picture data is packetized from one picture data into one packetized elepentary stream packet, and the above-mentioned is described in the Trump port packet header. Showing a packet containing intra-frame coded picture data,
It is characterized by transmitting.

Further, the digital data transmission apparatus according to the present invention packetizes packetized elepentary stream packets, which are packetized intra-frame coded picture data and predictive coded picture data, into fixed-length transport packets. , A digital data transmission device that scrambles the payload portion and transmits the scrambled data, wherein at least the intra-frame coded picture data is 1
It is characterized by including an encoding processing unit that packetizes the picture data into one packetized elevator stream packet, and encodes the packet data so as to indicate the packet including the intra-frame encoded picture data in the Trump port packet header.

Further, according to the digital data recording method of the present invention, a packetized elepentary stream packet in which intra-frame coded picture data and predictive coded picture data are packetized is packetized into a fixed-length transport packet. When recording a transport stream in which the payload part has been scrambled on a recording medium, the intra-frame coded picture data is
It is characterized in that one picture data is packetized into one packetized elevator stream packet and recorded in a recording medium together with a scramble key.

Further, the digital data recording apparatus according to the present invention packetizes packetized elepentary stream packets, which are packetized intra-frame coded picture data or predictive coded picture data, into fixed-length transport packets. , A digital data recording apparatus for recording a transport stream having a payload portion subjected to scrambling processing on a recording medium, wherein one picture data is packetized into one packetized elevator stream packet A scramble key extracting means for extracting the scramble key of the picture data from the transport stream, and a scramble key obtained by the scramble key extracting means for the packetized elepentist including the intra-frame encoded picture data. Characterized in that it comprises a recording control means for performing control of recording on a recording medium with Mupaketto.

Further, in the digital data reproducing method according to the present invention, the packetized elepentary stream packet in which the intra-frame coded picture data and the predictive coded picture data are packetized is packetized into a fixed length transport packet. A method for reproducing digital data in which a transport stream in which a payload portion of the transport packet is scrambled is reproduced from a recording medium.
Picture data is packetized into one packetized elementary stream packet and is recorded together with the scramble key. From the trick play area on the recording medium, the packetized elementary stream packet including the intra-frame encoded picture data is scrambled. It is characterized in that it is played back together with the key to perform variable speed playback.

Further, in the digital data reproducing apparatus according to the present invention, the packetized elepentary stream packet in which the intra-frame coded picture data and the predictive coded picture data are packetized is packetized into a fixed-length transport packet. A device for reproducing digital data, which reproduces a transport stream, in which a payload part of the transport packet is scrambled, through a recording medium. In the intra-frame encoded picture data, one picture data is one packetized element. From the trick play area on the recording medium, which is packetized into pentary stream packets and recorded with the scramble key, the packetized elepentary stream packet containing the intra-frame coded picture data is played back with the scramble key and the speed is changed. Characterized in that it comprises a variable-speed reproducing processing means for performing live.

Further, according to the digital data recording / reproducing method of the present invention, the packetized elepentary stream packet in which the intra-frame coded picture data and the predictive coded picture data are packetized is packetized into a fixed length transport packet. A method for recording / reproducing digital data, in which a transport stream obtained by scrambling the encrypted transport packet in its payload part is recorded / reproduced through a recording medium. When packetized packetized elepentary stream packets are packetized into fixed-length transport packets, and the transport stream with its payload section scrambled is recorded and played back via a recording medium,
As for the intra-frame coded picture data, one picture data is packetized into one packetized elevator stream packet and is recorded in the trick play area on the recording medium together with the scramble key. It is characterized in that a packetized elevator stream packet including encoded picture data is reproduced together with a scramble key to perform variable speed reproduction.

Further, in the digital data recording / reproducing apparatus according to the present invention, a packetized elepentary stream packet in which intra-frame coded picture data and predictive coded picture data are packetized is packetized into a fixed-length transport packet. A digital data recording / reproducing apparatus for recording / reproducing a transport stream, in which a payload part of an encrypted transport packet is scrambled, through a recording medium. When packetized packetized elepentary stream packets are packetized into fixed-length transport packets and the payload stream is scrambled, the transport stream is recorded / reproduced via a recording medium. The picture data includes a recording processing unit that packetizes one picture data into one packetized electric stream packet and records the packet in the trick play area on the recording medium together with the scramble key, and from the recording medium to the trick play area in the frame. Variable-speed reproduction processing means for reproducing variable-speed reproduction by reproducing a packetized elevator stream packet including encoded picture data together with a scramble key.

[0029]

In the digital data transmission method according to the present invention,
The intra-frame coded picture data is obtained by packetizing one picture data into one packetized elevator stream packet, and showing a packet including the above-mentioned intra-frame coded picture data in a trump port packet header.
To transmit.

Further, in the digital data transmission apparatus according to the present invention, at least the intra-frame coded picture data is packetized from one picture data into one packetized elepentary stream packet by the coding processing unit, and the Trump port. The packet header is encoded so as to indicate the packet including the intra-frame encoded picture data.

Further, in the digital data recording method according to the present invention, the intra-frame coded picture data is packetized from one picture data into one packetized elevator stream packet and recorded in the recording medium together with the scramble key. .

In the digital data recording apparatus according to the present invention, the scramble key extracting means transports the scramble key of the intra-frame coded picture data in which one picture data is packetized into one packetized elevator stream packet. Get from the stream. Further, the recording control means controls the recording of the scramble key obtained by the scramble key extracting means on the recording medium together with the packetized elevator stream packet including the intra-frame coded picture data.

In addition, in the digital data reproducing method according to the present invention, the intra-frame coded picture data is recorded on a recording medium in which one picture data is packetized into one packetized elevator stream packet and recorded together with the scramble key. From the trick play area of 1), the packetized elevator stream packet including the intra-frame coded picture data is reproduced together with the scramble key, and variable speed reproduction is performed.

Further, in the digital data reproducing apparatus according to the present invention, the intra-frame coded picture data is packetized by the variable speed reproduction processing means into one packetized one-packetized elevator packet together with the scramble key. From the recorded trick play area on the recording medium, the packetized elevator stream packet including the intra-frame coded picture data is reproduced together with the scramble key to perform variable speed reproduction.

Further, in the digital data recording / reproducing method according to the present invention, the intra-coded picture data is packetized into one packetized one-end stream packet and one picture data is packetized together with the scramble key on the recording medium. The data is recorded in the play area, and the packetized elevator stream packet including the intra-frame coded picture data is reproduced from the recording medium from the trick play area together with the scramble key to perform variable speed reproduction.

Furthermore, in the digital data recording / reproducing apparatus according to the present invention, the recording processing means packetizes the intra-frame coded picture data into one packetized one-packetized electric stream packet together with the scramble key. The trick play area is recorded on a recording medium, and the variable speed reproduction processing means reproduces a packetized elepentary stream packet including intra-frame coded picture data from the recording medium from the recording medium together with a scramble key and performs a variable speed reproduction. I do.

[0037]

Embodiments of the present invention will now be described in detail with reference to the drawings.

The digital data transmission method according to the present invention is carried out by a digital data transmission apparatus according to the present invention, which has a transmission system having the structure shown in FIG. 1, for example.

The transmission system of the ATV system shown in FIG.
It is a transmission system of the ATV system that adopts the MPEG2 system, which is a transport stream (TS: Transport Stream).
m) has a function of outputting a plurality of programs (streams) as a single stream, and a plurality of encoding processing units 100A, 100B, ... .., Program specification information (PSI: Proguram Specific Informati
on) is supplied to the first packetization processing unit 110, contract information (EMM: Entitlement Management Message) is supplied to the first packetization processing unit 120, the coding processing units 100A, 100B, ... Stream of each program coded by each of the packetization processing units 110,
Program specification information PS packetized by 120
Multiplexing processing unit 13 to which I and contract information EMM are supplied
0, the transport processing 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 section 100A includes a video compression encoder 101A to which a video signal forming the first program A is supplied, 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 such 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, as shown in FIG. 2, the PES packet is a 24-bit head start code, an 8-bit stream ID, and a 16-bit PE indicating the length of the packet.
S packet length, optional PES header, PES
It is composed of packet data (bytes).

The 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
Storage Media) trick mode, additional copy information, preceding packet CRC (Cyclic Redundancy Code)
And PES extension data.

Further, the PES extension data consists 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 transport packets (TP: Transport Packet), and the transport packets are 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 and is packetized into transport packets 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 packetized into a fixed-length transport packet, which is composed of a scramble processing unit 104B and a second multiplexing unit 105B to which ECM data including 2 is supplied. Are 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 with the same configuration and multiplexes the transport packet to generate a stream of each program.

Here, in the MPEG2 system, as a video signal, I picture data of an I frame that is intra-frame coded, P picture data of a P frame that is forward predictive coded, and B picture of a B frame that is bidirectionally predictive coded. Data is transmitted. In each of the encoding processing units 100A, 100B ... In this embodiment, when packetizing a video signal into a PES packet,
I picture data, P picture data, and B picture data are each packetized into individual PES packets, and P
The ES packet is packetized into a fixed-length transport packet, and the transport packet is multiplexed to generate a transport stream.

By packetizing the I picture data, the P picture data, and the B picture data into individual PES packets in this way, the I picture data, the P picture data, and the B picture data are contained in the transport packet.
The picture data will not be mixed.

Thus, in a recording system for recording such a transport stream on a recording medium, a PES packet containing only I picture data can be taken out from the transport stream and recorded on the recording medium together with its scramble key. As a result, in the reproducing system, the PES packet including only the I picture data can be reproduced together with the scramble key, and variable speed reproduction can be performed.

In order to enable variable speed reproduction in a recording / reproducing system for recording / reproducing a transport stream via a recording medium, at least 1 picture data is packetized into 1 PES, and a Trump port packet header is used. PES including the I picture data
By indicating and transmitting packets, in a recording / reproducing system for recording / reproducing a transport stream via a recording medium, a PES packet containing the I picture data is reproduced together with its scramble key to perform variable speed reproduction. Will be able to.

Here, a PE including the I picture data
To indicate an S packet by a trump port packet header, for example, a group of pictures (GOP: Group Of Pi
The sequence header may be inserted in units of cture).

That is, since the payload unit start indicator showing the start of the payload unit is "1" in the packet including the head of the PES packet and the random access indicator is "1" in the packet including the head of the video sequence header, It can be seen that the packet in which both the payload unit start indicator and the random access indicator are "1" is the head of the I picture data. Further, the packets up to the packet before the packet in which the payload unit start indicator becomes "1" are the packets including the I picture data.

Further, in the packet containing the I picture data, the packet containing the I picture data can be obtained by setting the transport priority to "1" or the elementary stream priority of the adaptation field to "1". Can be shown.

Next, the recording and reproducing method of digital data according to the present invention is carried out in a video recording and reproducing system having a structure as shown in FIG. 3, for example.

This video recording / reproducing system is based on MPEG.
Digital broadcasting using two systems, for example, ATV (Advanc
ed Television) scrambled broadcast bit stream is recorded and reproduced, and a receiving section 10 for receiving an ATV signal and converting a desired program into a standard television signal and outputting the same is provided. The recording / reproducing unit 20 records / reproduces the bit stream of the scrambled broadcast received by.

The receiving section 10 includes a front end 11 for receiving an ATV signal broadcast, and this front end 11
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.
on) is separated from the transport stream TS and sequentially supplied to the descramble processing unit 15.

The control section 14 includes a filter section 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 supplied via the DMUX 13. Then, the PAT analysis unit 1
4B is the program association table PA
The T is analyzed to detect the program map table packet identification information (PMT_PID: Program Map Table PID).
Further, the filter unit 14A extracts the program map table packet identification information PMT_PI from the transport packet supplied via the DMUX 13.
Program map table (PMT: Program based on D
(Map Table). Then, the PMT analysis unit 1
The 4C analyzes the program map table PMT to detect the elementary PID of each packet such as a video signal and an audio signal of a desired program and detects the D
Supply to MUX13.

The descrambling unit 15 uses the ECM for the transport packet of the desired program.
The 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 16
Reproduces a video signal and an audio signal by decoding the data descrambled by the descramble processing unit 15. Furthermore, the above NTCS / PA
The L encoder 17 converts the video signal and the audio signal reproduced by the video / audio decoder 16 into a television signal of NTCS system or PAL system and supplies it to a monitor device (not shown).

Here, as shown in FIG. 4, which shows the relationship between the ECM stream containing the scramble key and the scrambled bit stream, the payload part of the transport stream is normally updated at a constant period tD of about 1 to 2 seconds. It is scrambled by the scramble key.
Which of the even / odd scramble keys is used to scramble each packet is displayed in the packet header. Also, as a countermeasure against errors, a plurality of packets including the same scramble key are transmitted during the update cycle. Further, the packet including the scramble key is transmitted earlier than the packet actually scrambled by using the scramble key for a certain time tA or more, for example, about 100 ms.

Therefore, the demultiplexer 13 of the receiving unit 10 passes the ECM packet of the transport packet of the desired program to a smart card (not shown), and replaces it with the scramble key (Even / Od).
d) as shown in FIG. 5, the internal registers RegA, Reg
Store in B. The scramble key in the internal registers RegA and RegB is sent to the descramble processing unit 15 together with the corresponding packet sent thereafter. Further, in the demultiplexer 13, a new scramble key sent while the descramble processing unit 15 descrambles the corresponding packet using the scramble key is stored in another internal register RegC, RegD. When a packet corresponding to the scramble key is sent, the internal registers RegC, R
The scramble key in the egD is sent to the descramble processing unit 15.

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. 6, for example.

The recording system shown in FIG. 6 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 supplied from the DMUX 13 of the receiving unit 10 and recording the video signal from the input terminal 21. Equipped with. To the terminal 24A of the switch circuit 24, through the rate conversion and format conversion unit 29,
MPEG2 transport packets are supplied.

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 a 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.

As described above, when recording an MPEG2 transport packet, the rate conversion / format conversion unit 9 selects, for example, one program from among the multi-programs, and the data rate of the selected program is, for example, Converted from 30 Mbps to 10 Mbps. Here, since the time axis information changes, it is impossible to return to the same state at the time of recording as it is at the time of reproduction.

Therefore, in this embodiment, time information (packet arrival time) based on the reference clock is added to each packet before the stream of transport packets is input to the rate conversion buffer. At the time of reproduction, the same state as at the time of input can be maintained by transmitting at the same lock as at the time of input and transmitting the packet at the timing of this time information.

That is, as shown in FIG. 7A, an 8-byte sync is added to the header at the beginning of the transport packet. When recording an MPEG2 transport packet, 1 byte of this sync is taken out, and 3 bytes of time information is added thereto as shown in FIG. 7B.

That is, FIG. 8 shows a structure for adding time information of 3 bytes before rate-converting and recording the transport packet. This transport packet is supplied to the sync detection circuit 32. The sync detection circuit 32 detects the leading sync of the transport packet. The detection output of the sink is supplied to the latch 33. The output of the sync detection circuit 32 is supplied to the sync removal circuit 37. The sync removing circuit 37 removes one byte of the sync when the sync is detected. The output of the sync removal circuit 37 is supplied to the time stamp circuit 38.

The reference clock generation circuit 34 is, for example, 27
Generates a MHz reference clock. The reference clock is supplied to the PLL 35 and the counter 36. Based on the output of PLL35
It is rotated at 50 Hz.

The counter 36 counts the reference clock. Time information is obtained from the output of the counter 36. This time information is supplied from the counter 36 to the latch 33. The output of the time stamp circuit 38 is the output terminal 39.
Output from

When the sync detection circuit 32 detects the sync of the transport packet, the time information at this time is latched in the latch 33. Then, the sync detection circuit 37
, The sync of one packet is removed, and the time stamp circuit 38 adds time information of 3 bytes to the packet.

Further, as described above, the output of the reference clock generation circuit 34 is supplied to the PLL 35, and the drum is rotated by the output of the PLL 35, and the rotation of the drum is synchronized with the reference clock during recording and reproduction. As a result, the time information is retained during recording and reproduction.

The transport packet is 188 bytes, and if 1-byte sync is excluded and 3-byte time information is added, it becomes 190 bytes. In this 190-byte packet, 2 packets are 5 as shown in FIG.
It is packed in a sync block.

That is, in the digital VTR, one sync block has 90 bytes, and the sync and ID are added to the first 5 bytes. When 1 byte of parity is added, the payload of 1 sync block becomes 77 bytes. Furthermore, each sync block contains
This 1-byte extra header (see FIG. 10) is added. A serial number or the like in 5 sync blocks is added to the extra header. The remaining 78 bytes are allocated for packet recording. Therefore, 5 sync blocks are 5 × 76 = 380 bytes, and a 190-byte packet with time information added can be exactly packed into 5 × 190 = 380 bytes for two packets.

Further, in this embodiment, the playable area during variable speed reproduction is set as the trick play area, and the packet including the I frame is recorded in this trick play area. In MPEG2, an I frame that has been intra-frame coded, a P frame that has been forward predictively coded, and a B frame that has been bidirectionally predictively coded are being sent, and only I frame data can be used during variable speed reproduction. When the trick play area is provided, the data of the I frame obtained from the trick play area can be used during the variable speed reproduction.

That is, the recording rate of the digital VTR is 25 Mbps in SD mode. On the contrary,
When the transport packet is recorded at a rate of 10 Mbps, there is a margin in the recording rate. Therefore, the reproducible area at the time of variable speed reproduction is set as the trick play area, and the packet including the I frame can be recorded in duplicate in this trick play area.

For example, FIG. 11 shows the locus of the head during variable speed reproduction. As shown in FIG. 11, when the head traces, the portion indicated by TP becomes the reproducible area. This reproducible area TP is used as a trick play area for recording packets for variable speed reproduction. In the VTR of helical scan and azimuth recording, the data reproduced from the TP has a burst shape as shown in FIG. AT the position on the track of this playable area
If it is fixed by F or the like and a packet including an I frame is recorded in this reproducible area, the data of the I frame is always reproduced.

In this embodiment, two types of trick play areas TP-H and TP-L are provided. One trick play area TP-H is for high speed variable speed reproduction,
The other trick play area TP-L is for low speed variable speed reproduction. Each trick play area TP-H, TP-L
Are provided on tracks having different azimuth angles.
That is, in the digital VTR, as shown in FIG. 13, one track is classified into an ITI sector used for post-recording, an audio sector, a video sector, and a subcode sector used for searching. Then, it is traced by heads having different azimuth angles. As the head structure, two heads facing each other by 180 degrees and a double azimuth head can be used. Then, the pilot signal is superimposed in order to perform ATF tracking.

As shown in FIG. 14, the trick play area TP-H for high speed variable speed reproduction is provided, for example, in a track of the pilot signal f0 in an area which can be reproduced at 18 times speed. And the trick play area TP-
Data is recorded in H repeatedly 18 times. The trick play area TP-L for low speed uses the pilot signal f
It is provided in an area that can be played back at 4x speed on tracks other than 0. The same data is repeatedly recorded twice in the trick play area TP-L.

As described above, the trick play areas TP-H and TP-L are arranged on the tracks of different azimuths. Thus, in each trick play area TP-H and TP-L, by using only one azimuth track, there is no restriction on the head configuration such as two heads facing each other by 180 degrees and a double azimuth head. , Variable speed reproduction becomes possible.

Further, in the digital VTR, when the phase is locked, the tracking information is obtained in the track of the pilot signal of f0, so that the tracks of the pilot signal other than f0 are easily affected by the mounting error of the head. Therefore, the trick play area TP-L for low speed variable speed reproduction is arranged on the track of the pilot signal other than f0, and the trick play area T for high speed variable speed reproduction is provided.
P-H is arranged in the track of the pilot signal of f0. This is because, with 5 sync blocks at 18x speed and 25 sync blocks at 4x speed, the 4x speed has a larger margin for tracking deviation.

The same data is repeatedly recorded 18 times in the trick play area TP-H for variable speed reproduction for high speed, and the trick play area TP for variable speed reproduction for low speed is recorded.
The same data is repeatedly recorded twice in -L.

FIG. 15 is a block diagram showing the structure of the reproducing system of the recording / reproducing unit 20. In the reproducing system shown in FIG. 15, the recording signal of the magnetic tape is transferred to the rotary head 41.
And is supplied to the channel decoder 43 via the reproduction amplifier 42. Channel decoder 43
Is for demodulating 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 43 is supplied to a time base correction processing unit (TBC: Time Base Corrector) 44. The TBC 44 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 43. There is.

Then, the TBC 44 supplies the reproduction signal from which the time axis fluctuation component is removed to the deframe conversion circuit 45.
The deframing circuit 45 corresponds to the framing circuit 25 of the recording system, and performs error correction processing of the reproduced data from the TBC 44.

This reproducing system is provided with a switch circuit 46 which can be switched between reproducing an ATV system signal and reproducing a component video signal. The output of the deframe circuit 45 is supplied to the switch circuit 46. When the reproduction signal is an ATV system signal, the switch circuit 4
6 is switched to the terminal 46A side. When the reproduced signal is a component video signal, the switch circuit 46 is switched to the terminal 46B side.

The DCT expansion circuit 47 having the switch circuit 46 connected to the terminal 46B corresponds to the DCT compression circuit 23 of the recording system. That is, the DCT expansion circuit 47
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 47 has
The output of the terminal 46B of the switch circuit 46 is supplied to the DC
The T-expansion circuit 47 restores the reproduced data to a baseband video signal, and this video signal is output from the output terminal 48.

Further, the output of the terminal 46A of the switch circuit 46 is supplied to the packet selecting section 49. And A
During normal reproduction of a TV system signal, the packet selection unit 49
Selects all the packets of the reproduction data supplied via the switch circuit 46. On the other hand, during variable speed reproduction, the packet selection unit 49 selects and outputs an I picture packet obtained by reproducing the trick play area TP. The output of the packet selection unit 49 is output from the output terminal 50.

The controller 51 controls to switch between normal reproduction and variable speed reproduction. A mode setting signal is supplied to the controller 51 from the input unit 52. The servo circuit 53 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 53 by feeding back the 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 required 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 section 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 reproducing 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).

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,
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 controller 14 of the receiver 10 is
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 of 0, the filter unit 14
At A, the program map table PMT is taken out. Then, the 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 unit 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 of the recording / playback unit 20 supplied to the X13, a packet including a video elementary stream, an audio elementary stream , And the packet containing the data elementary stream is separated,
Decoding / playback processing can be performed.

In the recording / reproducing system having such a receiving unit 10, when the recording / reproducing unit 20 performs normal recording / reproducing, the scrambled bit stream and the ECM stream corresponding thereto are all recorded together. In other words, since the time relationship between the scrambled bit stream and the scramble key is maintained as it is, it can be descrambled as usual in the set-top box STB by sending it back as it is during reproduction.

However, in the variable speed reproduction, only a part of the bit stream, that is, the data of the I frame is reproduced intermittently. Therefore, the scrambled bit stream and the ECM stream corresponding thereto are all recorded together. If so, as shown in FIG. 16, the relationship between the scrambled bit stream and the scramble key changes significantly, so that the descramble processing unit 15 does not operate normally.

For example, when recording with the tape pattern shown in FIG. 14, trick play data TP- for high speed reproduction is used.
The recording rate of H is: 6 × 2 × 188 × 300/2/18 = 150.4 Kbps Assuming that the size of I picture data is 800 Kbits, 800 × 10 ³ /150.4×10 ³ = 5.3 s, which is 1 It takes 5.3 seconds to record the I picture data for a frame. Assuming that the GOP of the input video stream is 15, the period for transmitting the I picture is 0.
Since it is about 5 seconds, 5.3 / 0.5 = 10.6, and the I picture is recorded as the variable speed reproduction data about once every 11 times.

Therefore, only the packet including the scramble key corresponding to the variable speed reproduction data (I picture) packet is recorded together. Note that the cycle (variable) in which the I picture is transmitted and the cycle in which the scramble key is updated are not normally synchronized, so recording is performed via the memory 7 of the ECM recording processing block having the configuration shown in FIG. To do.

That is, in this ECM recording processing block, the PID filter block 61 extracts video packets and ECM packets according to the analysis result of the program map table PMT.

The video packet is supplied to the I-picture packet detector 62. The I-picture packet detection unit 62 detects an I-picture packet from the video packet based on the transport header, and uses this I-picture packet as variable-speed reproduction data. On the other hand, as the ECM packet, a packet including a scramble key (Even / Odd) is extracted and stored in the memory 63. Since the scramble key is transmitted prior to the corresponding scramble packet, it is first stored in the memory 63 and then updated in the memory 63 together with the update of the scramble key.
As a result, at the time when the I picture packet is detected, the corresponding scramble key is stored in the memory 63.

This scramble key is recorded together with the variable speed reproduction data, that is, the I picture data. Before that, the scramble key check unit 64 checks whether the scramble key is an even scramble key or an odd scramble key. To do. Since the scramble key packet for variable speed reproduction is recorded intermittently, the Even / Odd flag may remain the same even if the scramble key is actually updated. Therefore, in the scramble key inversion processing unit 65, the Even / Odd flag of the previously recorded scramble key is memorized and collated with it before recording, and if it has the same polarity as shown in FIG. Record after reversing Even / Odd).
Further, when the polarity of the scramble key is changed, the I-picture packet header inversion processing unit 66 changes the polarity of the corresponding I-picture packet header (Even / O).
Also change dd). The scramble key inversion processing unit 65
And the output of the I picture packet header inversion processing unit 66, that is, the scramble key and the I picture data corresponding to each other are supplied from the memory 6 to the formatting system processing unit 68 of the recording system, so that the scramble key is recorded together with the variable speed reproduction data. It

When the scramble key is updated in the middle of the recorded I-picture packet, it can be known from the Even / Odd flag of the packet header. Therefore, the updated scramble key is used as the variable speed reproduction data from that point. Record together.

Since the time interval of the recorded I picture data is usually longer than the scramble key update period, different I pictures are not scrambled by the same scramble key. However, the interval between I pictures recorded / reproduced on / from the recording medium depends on the picture size, and the picture size changes depending on the content of the image, the bit rate, etc. Therefore, different I pictures are scrambled by the same scramble key. There is a possibility. Even in that case, the scramble key is recorded together with each new picture data even if the scramble key is not updated.

In the actual recording, the ECM packet may be recorded in the trick play area as in the I picture packet, or the ECM packet may be recorded in the spare data (VAUX) area.
It can also be recorded as a packet including a packet (scramble key). When an ECM packet is recorded in the trick play area, it can be identified from the PID of the packet whether the I picture packet is an ECM packet. Also, 1 bit (I picture / EC) of the SB extra header prepared for 1 byte for each sync block.
It is also possible to identify M).

Further, in the recording / reproducing system of this embodiment, at the time of reproduction, the variable speed reproduction can be performed by the same processing as the processing of the basically clear bit stream. However, as shown in FIG. 19, in the backward variable speed reproduction, for example, there may be a case where the even scramble key is continuous even though the content of the scramble key is changed between different pictures. In this case, since the receiving unit 10 side cannot detect that the scramble key has been changed, the data selection unit 71, the Xectra header detection unit 72, the memory 73, the control unit 74, and the ECM detection unit having the configuration shown in FIG. When the EVEN scramble key or the Odd scramble key is continuous by the ECM reproduction processing block including the polarity (Evev / Odd) detection unit 76 and the polarity (Evev / Odd) inversion unit 77,
Similar to the above-mentioned recording system, the polarity (Evev / Odd) inversion processing of the ECM packet and I picture packet is performed.

Here, for example, in the case of reproducing the data recorded with the tape pattern shown in FIG. 14 described above, the output rate of the variable speed reproduction is maximized when the trick play data TP-H for high speed reproduction is reproduced. The output rate at that time is (6 × 2 × 188 × 8 × 300/2/18) × 18 = 2.7 Mbps.

The data size of the I picture data is set to 800
When ^{Kbits, 2.7 × 10 6/800} × 10 3 = 0.28 frames / sec = 1 / 3.5, and the one frame of I picture data every 3-4 seconds is delivered.

If each I picture data is recorded together with a different scramble key, if the trick play data TP-H for high speed reproduction is reproduced at a variable speed of 1.5 times, the output rate is low. Is not particularly problematic because the renewed scramble key is updated every 3 to 4 seconds, but the trick play data TP-H for high speed reproduction is set to 1
When the output rate is high as in the case of variable speed reproduction at 8 times speed, the renewed scramble key is updated 3 to 4 times per second, and the smart card on the receiving unit 10 side receives the ECM. After that, the time required for creating the scramble key and loading it in the descramble processing unit 15 becomes insufficient.

Therefore, as a control of the timing of transmitting the reproduction data, the minimum time t _A before the ECM (scramble key) data precedes the corresponding I picture data and the cycle t _D for updating the ECM (scramble key) data are set. The timing for transmitting the reproduction data is controlled in consideration.

That is, as shown in FIG. 21, for example, first, an ECM packet is transmitted, but the same ECM (scramble key) data is transmitted within the transmission time t _R in consideration of packet loss due to a transmission error. Send multiple times. After a time t _{A has} elapsed from the time when the ECM packet has been transmitted, the corresponding I picture packet is transmitted. Above t
_At time _A , the smart card on the receiver 10 side is ECM
Is determined by the time required from the receipt of the scramble key to the generation of the scramble key and the loading of the scramble key into the descramble processing unit 15. Next, the transmission of the next ECM packet is started at a time when t _E time has elapsed from the I picture transmission start time, and after the elapse of t _A time from the transmission end time, the corresponding I picture packet is transmitted.

Here, the time t _E is set so that consecutive I pictures are not transmitted in time. Also, the ECM data and I-picture data reproduced by the time when the next ECM packet is transmitted are the above-mentioned receiving unit 1
Discard without sending to 0.

As a result, the execution output rate of the I picture data is determined by the transmission timing of the ECM (scramble key) data, becomes lower than the output rate of the reproduced I picture data, and the screen update rate decreases, but it is acceptable. It becomes possible to obtain the reproduction output of the image quality.

A concrete example of the output control section for variable speed reproduction is shown in FIG.
Shown in

The output controller for variable speed reproduction shown in FIG. 22 comprises the memory 73 as a virtual memory bank, and has a write controller 74W ₁ and a read controller 7.
Speed playback data bank switching by 4R ₁ (I
Picture data) memories 73A and 73B, and ECM data memories 73C and 73D whose banks are switched by the write controller 74W ₂ and the read controller 74R ₂ .

The write control sections 74W ₁ and 74W ₂ are provided with the detection output of the update detection section 72A for detecting that the scramble key has been updated from the reproduced ECM data. Further, the update detection unit 72
When the detection output of A is given to the write control sections 74W ₁ and 74W ₂ , the write addresses are transferred to the read control sections 74R via the latch circuits 74L ₁ and 74L ₂ , respectively.
₁ , 74R ₂ .

Also, the variable speed reproduction data memory 73 is used.
A and 73B have a storage capacity for one frame of I picture. Further, the ECM data memories 73C, 7
Since 3D is not limited to one ECM (scramble key) data for one I picture, 3D has a storage capacity of several packets so that ECM (scramble key) data can be stored.

In the output control section for variable speed reproduction, as shown in the read control timing chart of FIG. 23, when the recording / reproducing section 20 is in the variable speed reproduction mode and the TP start flag tp_start becomes "L", the frame toggle is performed. At the second inversion time t ₁ of the flag frame_toggle, the bank switching flag bnk_chg becomes “L” and the ECM enable flag ecm_en becomes “L”, and the reading of the ECM data memories 73C and 73D is started. At this time, the update flag ks_chg is also set to "L".

ECM (scramble key) data is read out until a time t ₂ when a predetermined time has passed from the time t _1, and the ECM enable flag ecm_en is set to "H" at the time t ₂ to finish the reading. After that, at time t ₃ after the lapse of time t _A , the TP enable flag tp_en is set to “L”, and the reading of the variable speed reproduction data memories 73A and 73B is started.

The variable speed reproduction data memories 73A, 73
While reading B, the update address (Ks Address Chang
When it reaches the e), the update flag ks_chg is reversed, the TP enable flag tp_en as "H", interrupts the reading (time t _4). In this case, since the updated ECM (scramble key) data is written in the ECM data memories 73C and 73D, the ECM data is re-written.
With the enable flag ecm_en set to "L", the updated ECM (scramble key) data in the ECM data memories 73C and 73D is read. Then, the ECM enable flag ecm_en becomes “H” at time t ₅ after the elapse of a predetermined time, the reading is completed, and the TP enable flag tp_en is set to “L” at time t ₆ after the time t _{A has} elapsed from that, and the above-mentioned shift The reading of the data in the reproduction data memories 73A and 73B is started from the next to the interrupted address. When all the data is read, the above TP enable flag tp_ at time t _7.
en becomes "H", and ends the reading, performs bank switching to "H" bank switching flag bnk_chg with inversion time t ₈ for the next frame toggle flag Frame_toggle.

Since the I picture is not always reproduced from the beginning during reproduction, complete I picture data and ECM (scramble key) are stored in the memory when the frame toggle flag frame_toggle is inverted twice. It is guaranteed that the data has been written.

Further, as shown in the write control timing chart in FIG. 24, on the write side, even if new I picture data and ECM data are reproduced by the inversion of the frame toggle flag frame_toggle, the reading is basically completed. Overwrite until you do. Meanwhile, when new I-picture data is input, the address reset address_reset is used to write from the start address of the I-picture data. The ECM data is the same, but if the scramble key is updated in the middle of the picture, the new scramble key is written to another address. Time t ₂ at which the bank is switched after reading is completed
Corresponds to the inversion time of the frame toggle flag frame_toggle, which means that the writing for one picture is completed.

Since the PES header is scrambled in the bit stream scrambled as described above, the presentation time stamp PTS / decoding time stamp DTS in the PES header contains the value at the time of encoding, and the receiving unit At 10, it cannot be replaced with a new value during variable speed reproduction.

Therefore, in the receiving section 10, the decoding / display timing during variable speed reproduction does not depend on the value of PTS / DTS in the bit stream, and the decoding / display timing is performed at the vertical synchronization timing after one picture data is accumulated in the buffer. Display.

[0136]

As described above, according to the present invention, the intra-frame coded picture data is packetized from one picture data into one packetized elepentary stream packet, and the intra-frame coded picture is recorded by the Trump port packet header. Since the packet including the data is shown and transmitted, the I picture data and the P
The picture data and the B picture data do not coexist. As a result, in a recording system for recording such a transport stream on a recording medium, a PES packet containing only I picture data can be taken out from the transport stream and recorded on the recording medium together with its scramble key. In the reproducing system, the PES packet containing only the I picture data is reproduced together with the scramble key, and variable speed reproduction can be performed.

Therefore, according to the present invention, the variable speed reproduction of the scrambled program can be realized.

[0138]

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a transmission system in a digital data transmission device according to the present invention.

FIG. 2 is a diagram showing a configuration of a PES packet of digital data transmitted by the transmission device.

FIG. 3 is a block diagram showing a configuration of a video recording / reproducing system to which the present invention is applied.

FIG. 4 is a diagram showing a relationship between an ECM stream including a scramble key and a scrambled bit stream in the video recording / reproducing system.

FIG. 5 is a diagram showing a configuration of an internal register that stores a scramble key in the demultiplexer 13 of the receiving unit in the video recording / reproducing system.

FIG. 6 is a block diagram showing a configuration of a recording system of a recording / reproducing unit in the video recording / reproducing system.

FIG. 7 is a diagram showing the content of additional information of the header at the beginning of a transport packet.

FIG. 8 is a block diagram showing a configuration for adding 3-byte time information before rate-converting and recording a transport packet.

FIG. 9 is a diagram showing a transport packet for 2 packets packed in 5 sync blocks.

FIG. 10 is a diagram showing the contents of an extra header.

FIG. 11 is a diagram showing a locus of the head during variable speed reproduction in the recording / reproducing unit.

FIG. 12 is a diagram showing an output waveform of the head during variable speed reproduction in the recording / reproducing unit.

FIG. 13 is a diagram showing a configuration of tracks in the recording / reproducing unit.

FIG. 14 is a diagram showing a trick play area in the recording / reproducing unit.

FIG. 15 is a block diagram showing a structure of a reproducing system of the recording / reproducing unit.

FIG. 16 is a diagram showing a relationship between a scrambled bit stream and a scramble key by variable speed reproduction in the recording / reproducing unit.

FIG. 17 is a block diagram showing a configuration of an ECM recording processing block in the recording system of the recording / reproducing unit.

FIG. 18 is a diagram showing a function of a scramble key inversion processing unit in the ECM recording processing block.

FIG. 19 is a diagram showing a state in which the scramble key generated by the backward variable speed reproduction is continuous in the recording / reproduction system.

FIG. 20 is a block diagram showing the configuration of an ECM reproduction processing block in the reproduction system of the recording / reproducing unit.

FIG. 21 is a diagram showing a transmission state of each packet in the recording / reproducing unit.

FIG. 22 is a diagram showing a specific example of an output control unit for variable speed reproduction in the reproduction system of the recording / reproduction unit.

FIG. 23 is a timing chart of read control in the output control section.

FIG. 24 is a timing chart of write control in the output control unit.

FIG. 25 is a diagram showing the structure of a transport packet.

FIG. 26 is a diagram for explaining recording of a time division multiplexed multi program.

FIG. 27 is a block diagram showing a configuration of a CA system of a conditional access system in general.

FIG. 28 is a diagram showing the contents of program information including a scramble key transmitted in an ECM packet.

FIG. 29 is a work key Ks transmitted in an EMM packet.
It is a figure which shows the content of the program information containing.

[Explanation of symbols]

 10 receiving unit 13 demultiplexer 14 control unit 15 descramble processing unit 20 recording / reproducing unit 29 rate conversion and format conversion unit 39 packet selection unit

Claims (10)

[Claims] 1. A packetized elevator stream packet in which intra-frame coded picture data and predictive coded picture data are packetized into a fixed-length transport packet, and the payload part is scrambled for transmission. In doing so, at least the intra-frame coded picture data is packetized from one picture data into one packetized elevator stream packet, and the packet containing the intra-frame coded picture data is indicated by the Trump port packet header and transmitted. A method for transmitting digital data characterized by the above. 2. The method of transmitting digital data according to claim 1, wherein a packet including the intra-frame coded picture data is indicated by inserting a sequence header in units of groups of pictures. 3. A packetized elevator stream packet in which intra-frame coded picture data and predictive coded picture data are packetized into a fixed-length transport packet, and the payload part is scrambled and transmitted. A device for transmitting digital data, wherein at least the intra-frame encoded picture data is packetized from one picture data into one packetized elevator stream packet, and the intra-frame encoded picture data is included in a trump port packet header. An apparatus for transmitting digital data, comprising: an encoding processing unit that encodes so as to indicate a packet. 4. The digital data according to claim 3, wherein the encoding processing unit inserts a sequence header for each group of pictures to indicate a packet including the intra-frame encoded picture data. Transmission equipment. 5. A packetized packetized packet of the intra-frame coded picture data and predictive coded picture data is packetized into a fixed-length transport packet, and the payload is scrambled. When recording the port stream on the recording medium, the intra-frame coded picture data is characterized in that one picture data is packetized into one packetized elevator stream packet and recorded on the recording medium together with the scramble key. How to record data. 6. A transcoder in which a packetized elevator stream packet in which intra-frame coded picture data and predictive coded picture data are packetized is packetized into a fixed-length transport packet, and its payload part is scrambled. A device for recording digital data for recording a port stream on a recording medium, wherein a scramble key of intra-frame coded picture data in which 1 picture data is packetized into 1 packetized elevator stream packet is transmitted from the transport stream. Scramble key extracting means for extracting, and control for recording the scramble key obtained by the scramble key extracting means on a recording medium together with the packetized elevator stream packet containing the intra-frame coded picture data. Recording apparatus for digital data, characterized in that it comprises a recording control means for performing. 7. A scramble process for a transport packet, which is a packetized packet packet of a packetized elevator stream packet in which intra-frame coded picture data and predictive coded picture data are packetized, into a fixed-length transport packet. A method for reproducing digital data, which reproduces a transport stream subjected to the above from a recording medium, wherein one intra-frame encoded picture data is packetized into one packetized elepentary stream packet and recorded together with a scramble key. Playback of digital data characterized by performing variable speed playback from the trick play area on the recorded recording medium by playing back the packetized elevator stream packet containing the intra-frame coded picture data together with the scramble key. Law. 8. A scramble process of a transport packet, which is a packetized packet packet of a packetized elevator stream packet obtained by packetizing intra-frame coded picture data or predictive coded picture data, into a fixed-length transport packet. A device for reproducing digital data which reproduces a transport stream which has been subjected to recording through a recording medium, wherein intra-frame coded picture data is packetized by converting one picture data into one packetized elevator stream packet and a scramble key. And a variable speed reproduction processing means for reproducing variable speed packetized reproduction packet packets including intra-frame coded picture data together with the scramble key from the trick play area recorded on the recording medium. Reproducing apparatus of digital data. 9. A scramble processing of a transport packet, which is a packetized packetized packet of a packetized elevator stream packet in which intra-frame coded picture data and predictive coded picture data are packetized, into its payload part. A method for recording / reproducing digital data, which records / reproduces a transport stream on which a packet has been recorded, through a recording medium, comprising a packetized elevator stream packet formed by packetizing intra-frame encoded picture data or predictive encoded picture data. When recording and reproducing a transport stream in which fixed-length transport packets are packetized and the payload part is scrambled through a recording medium, the intra-frame encoded picture data is one packetized one picture data. Packetized into an electric stream packet together with the scramble key in the trick play area on the recording medium, and scramble the packetized electric stream packet including the intra-frame coded picture data from the trick play area from the recording medium. A method for recording and reproducing digital data, which is characterized by performing variable speed reproduction by reproducing with a key. 10. A scramble process of a transport packet, which is a packetized packet packet of a packetized elevator stream packet obtained by packetizing intra-frame coded picture data and predictive coded picture data, into a fixed-length transport packet, A recording / reproducing apparatus for digital data for recording / reproducing a transport stream on which a packet is recorded through a recording medium, which is a packetized elevator stream packet in which intra-frame encoded picture data or predictive encoded picture data is packetized. When recording and reproducing a transport stream in which fixed-length transport packets are packetized and the payload part is scrambled through a recording medium, the intra-frame encoded picture data is one packet of one picture data. Recording processing means for packetizing the packet into a stream stream packet and recording it in the trick play area on the recording medium together with the scramble key; A digital data recording / reproducing apparatus comprising: a variable speed reproduction processing means for reproducing a restream packet together with a scramble key to perform variable speed reproduction.