Packetized data formats for digital data storage media

<u style="single">Industrial application field</u>The present invention relates to the field of digital signal processing, in particular, in digital video data for the formation and storage of Program Specific Information (PSI) used to restore program content. Regarding inserting.<u style="single">Background of the invention</u>For video processing and storage applications (applications), digital video data is typically encoded to meet the requirements of known standards. As one of the widely adopted standards, there is an image coding standard by MPEG2 (Moving Pictures Expert Group), which will be referred to as "MPEG standard" below. This MPEG standard is based on the system coding section (ISO / IEC 13818-1, June 10, 1994) and the video coding section (ISO / IEC). 13818-2, January 20, 1995). These are referred to below as the "MPEG system standard" and the "MPEG video standard", respectively. Video data encoded in the MPEG standard is usually in the form of a packetized data stream containing the data content of many program channels (eg, channels 1-125). For example, for display, the decoder decodes the packetized data stream and identifies individual packets containing the channel of the selected program to restore the video data content of the channel of the selected program. Must be assembled. The MPEG standard is Program Specific, which is used to identify and assemble individual data packets to restore the contents of the selected program channel. Information: PSI) is defined. The PSI contains both user-definable and instructional information elements and should contain sufficient information to restore the data content of all program channels, including packetized data streams. Defined, in addition, the PSI is embedded in the packetized data stream. This increases the storage capacity required to store the data stream and reduces the communication bandwidth available for communication of program content. Therefore, PSI represents an additional coding overhead. The amount of overhead the PSI imposes depends on the amount of data contained in the PSI (the size or size of the PSI) and the number of times the PSI repeats in the packetized data stream. At a minimum, the PSI must contain enough information to restore the data content of all program channels, including packetized data streams. The minimum number of repetitions of PSI in a packetized data stream is limited by the operating delay characteristics of the desired system. For example, the decoder needs an updated PSI to perform program channel changes that give commands to television viewers. Therefore, the minimum number of repetitions of PSI is limited by how much the television viewer can tolerate the delay (waiting time) in response to a change in channel command. These issues are addressed by the system according to the invention. The inventors of the present application have recognized that it is desirable to reduce the overhead imposed by PSI in certain applications. For example, in a capacity-limited digital storage application, it is advantageous to reduce the size of the PSI stored on the recording medium and reduce the number of times the PSI is repeated on the recording medium. In some applications related to video processing, it is desirable to reduce the size of the PSI so that the PSI can be repeated more frequently, thereby reducing the restore latency of the program content. In addition, the generated PSI must meet the operating characteristics of the selected recording medium and the user's requirements. In addition, the inventors of the present application put PSI on a recording medium in a format that minimizes misuse of PSI in one program when restoring the contents of a second program that requires various restoration parameters. I realized that it is desirable to save. Such a situation occurs when the recording medium is used to store programs obtained from different packetized data streams, for example, the recording medium is partially overwritten (over) with programs obtained from different data streams. Occurs when it is lit). Ideally, the PSI storage format reduces the program restore latency and minimizes the restore time of random access data. High-speed random access is particularly important in the operation of recording devices that involve high-speed playback or content skipping (trick play), such as in the case of VCRs (video cassette recorders).<u style="single">Outline of the invention</u>A video processing system according to the principles of the present invention reduces the processing and storage overhead imposed by Program Specific Information (PSI) used to restore program content. The disclosed system provides compressed PSI and adaptively inserts this compressed PSI into a packetized data stream to reduce processing and storage overhead. The system adaptively generates PSI for a variety of media formats, such as videotapes, digital video discs (DVDs), or CDROMs. It also discloses a recording medium format and a packetized data stream format that enhance the efficiency of data processing by using compressed PSI. This disclosed storage and data stream format reduces program restore latency and minimizes the use of rogue PSI parameters across program boundaries. A recording medium format for a recording medium that contains multiple programs consisting of packetized data is a packet identifier (Packet) that identifies the individual packetized data streams that make up a program. Identifier: PID) is included. This data format makes it easy for the decoder to associate and assemble the packetized data stream of the program, regardless of the PID de-mapping data. The packet identifier contains a base PID to identify one data stream and a second PID to identify a second data stream, where the second PID is a given offset value to the base PID. Is. The same PID is given to the corresponding packetized data streams that make up different programs. Another recording medium format for recording media that contains a program consisting of packetized data contains program-specific information (PSI) suitable for use in restoring the data content of the program. This PSI contains a Program Map Table (PMT) that associates the packet identifiers (PIDs) with the individual packetized data streams that make up the program. The PSI also includes a Program Association Table that associates the program with the PID that identifies the packet containing the PMT. When decoding a program, it contains the appropriate parameters to command the decoder to apply to PSI, regardless of the previous PSI content. As a feature of the present invention, it is incorporated in a PSI in which a version number is stored in order to identify a difference between different versions of the PSI. This version number changes between successive occurrences of PSI, regardless of any substantial change in the content of the continuous PSI. Another feature of the invention is that one or more personal data elements are included in the stored PMT that describes the program. This data element is selected from a list of title, duration, program description, radicality grading, age suitability grading, recording period, recording date, and version.<u style="single">[Simple explanation of drawings]</u>FIG. 1 shows a video receiver system according to the invention that adaptively generates compressed PSI and inserts it into a packetized data stream for storage on various types of recording media. FIG. 2 shows a flow chart of the process of generating compressed Program Specific Information (CPSI) from a PSI and incorporating it into a packetized data stream suitable for storage on selectable recording media. FIG. 3 shows a flow chart of the process of forming a CPSI to store the selected program on the selected recording medium. FIG. 4 shows a flow chart of the process of formatting the CPSI so that the correct CPSI is used while the program is decrypted. FIG. 5 shows a flowchart of the process of playing the selected program from the selected storage device.<u style="single">Detailed description of the invention</u>FIG. 1 shows a video receiver system according to the invention that adaptively generates compressed PSI and inserts it into a packetized data stream for storage on a recording medium. This receiver system adaptively generates PSI for various types of media, such as videotapes, digital videodiscs (DVDs), or CDROMs. The video receiver system also reduces the processing and storage (recording) overhead imposed by the Program Specific Information (PSI) used to reproduce the program content. The system disclosed herein is described in connection with an MPEG compatible (MPEG compatible) system for receiving an MPEG coded transport stream representing a program to be broadcast. However, it is only an example. The principles of the present invention can also be applied to non-MPEG compatible (MPEG-incompatible) type systems with other types of encoded data streams. For example, the principles of the present invention can also be applied to digital video disc (DVD) systems and MPEG program streams. Also, the disclosed system is described as processing a broadcast program (program), but this is only exemplary. The term'program'refers to any form of packetized data, such as telephone messages, computer programs, internet data or other communication information. Briefly, in the receiver system of FIG. 1, the carrier wave modulated by the video data is received by the antenna 10 and processed by the input processing device 15. The resulting digital output signal is demodulated by the demodulator 20 and decoded by the decoder 30. The output from the decoder 30 is processed by the transport system 25, which responds to commands from the remote control unit (remote control) 125. System 25 provides compressed data output for recording, further decoding, or transmission to other devices. The user of the video receiver selects the program (program) he / she wants to watch, the program he / she wants to store, the type of recording medium and the storage (recording) method from the on-screen menu using the remote control 125. .. The video decoder 85 and the audio decoder 80, respectively, decode the compressed data from the system 25 to produce output for display. The data port 75 provides an interface for transmitting compressed data from the system 25 to another device, such as a computer or high definition television (HDTV) receiver. The storage device 90 stores the compressed data from the system 25 in the recording medium 105. The storage device 90 can also be decoded, transmitted to another device, or another recording medium (simplifying drawings). in playback mode, system 25 for storage (recording) on not shown for ). Assists in retrieving compressed data from recording media 105 for processing by. Considering FIG. 1 in detail, the carrier wave modulated by the video data received by the antenna 10 is converted into a digital format by the input processing device 15 and processed. The input processor 15 includes a radio frequency (RF) tuner, an intermediate frequency (IF) mixer, and an amplification stage for low frequency degradation that converts the input video signal into a relatively low frequency band suitable for further processing. Includes. The resulting digital output signal is demodulated by the demodulator 20 and decoded by the decoder 30. The output from the decoder 30 is further processed by the transport system 25. The multiplexer (MUX) 37 of the service detector 33 turns the selector 35 to output the output from the decoder 30 or the output of the decoder 30 further processed by the NRSS (National Renewable Standards Committee) descrambler device 40. Be supplied. The selector 35 detects the presence of an insertable descrambling card compatible with NRSS and outputs the output of the descrambler 40 only if the card is currently inserted in the video receiver. Supply to MUX37 (NRSS removable conditional access system is specified in EIA Draft IS-679, Project PN-3639). If the presence of the descramble card is not detected, the selector 35 supplies the output from the decoder 30 to the MUX37. In the presence of insertable cards, the descrambler 40, for example, descrambles an additional premium program channel to provide an additional program service to the viewer. Notably, in this preferred embodiment, the NRSS descrambler 40 and the smart card unit 130 (the smart card unit 130 is described below) share the same system 25 interface and at once. Either an NRSS card or a smart card is inserted. However, the interfaces may be separate to allow parallel operation. The data supplied from selector 35 to MUX37 is in the form of a packetized transport data stream according to MPEG, as specified in Section 2.4 of the MPEG System Standard, for one or more program channels. Contains data content. Individual packets containing a particular program channel are identified by a Packet Identifier (PID). The transport stream is the program-specific information used to identify the PID and assemble individual data packets in order to reproduce the contents of all program channels, including packetized data streams. Includes (Program Specific Information: PSI). The user of the video receiver selects the program (program) he / she wants to watch, the program he / she wants to store, and the storage (recording) medium for recording from the on-screen menu using the remote control 125. The system controller 115 uses the selection information (supplied via interface 120) to select a PSI suitable for storage (recording) and display of the program and the selected storage device and recording medium. Configure system 25 to occur. The controller 115 sets and controls the values of the control registers inside these elements via the data bus to configure the elements 45,47,50,55,65,95 of the transport system 25. Signal C selects the signal path through MUX37 and 110. In response to control signal C, the MUX 37 selects either a transport stream from selector 35 or, in replay mode, a data stream retrieved from storage device 90 via storage (recording) interface 95. In normal non-playback operation, data packets containing programs selected for viewing by the user are identified by their PIDs on the decryption PID selection device 45. When the encrption indicator in the header data of the selected program packet indicates that these packets are encrypted, the decryption PID selection device 45 sends these packets to the decryption device 50. send. If the packet is unencrypted, the decryption PID selector 45 sends the unencrypted packet to the transport decoder 55. Similarly, data packets containing programs selected for storage by the user are identified by their PIDs on the recording PID selection device 47. The recording PID selection device 47 sends the encrypted packet to the decryption device 50 and the unencrypted packet to the MUX 110 based on the information of the encryption index in the packet header. The decryption PID selection device 45 and the recording PID selection device 47 use the PID detection filter to obtain the PID of the incoming packet supplied from the MUX 37 by the controller 115 inside the decryption PID selection device 45 and the recording PID selection device 47. Matches with the PID value preloaded in the control register. The preloaded PID is used by the recording PID selection device 47 and the decoding PID selection device 45 to identify the data packet to be stored and the data packet to be decrypted to generate the video image. .. The preloaded PID is stored in the lookup table in the decryption PID selection device 45 and the recording PID selection device 47. The PID lookup table is memory-mapped to the encryption key table in the decryption PID selection device 45 and the recording PID selection device 47, which associates the encryption key with each preloaded PID. With the memory-mapped PID lookup table and encryption key lookup table, the decryption PID selection device 45 and the recording PID selection device 47 send an encrypted packet containing the preloaded PID to it. Matches with an encryption key that allows the associated decryption. Unencrypted packets do not have an associated encryption key. The decryption PID selection device 45 and the recording PID selection device 47 send the identified packet and its associated encryption key to the decryption device 50. Also, the PID lookup table in the decryption PID selection device 45 is memory-mapped to the destination table. This destination table matches the packet containing the preloaded PID with the position of the destination buffer in the corresponding packet buffer 60. The address of the destination buffer location associated with the encryption key and the program that the user chooses to view or store, along with the PID assigned by controller 115, is the decryption PID selection device 45 and the recording PID selection device 4 Preloaded in 7. The encryption key is generated from the encryption code extracted from the input data stream by the smart card system 130 according to ISO7816-3. The generation of this encryption key depends on the customer's entitlement, which is determined from the pre-encoded information stored in the insertable smart card itself (Document of the 1989 International Organization for Standardization (ISO7816-3). Specifies the interface and signal configuration for a smart card system). The packets supplied by the decryption PID selector 45 and the recording PID selector 47 to the decryption device 50 are Federal Information Standards (FIPS) publications 46, 74 and 81 provided by the National Technical Information Service of the Ministry of Commerce. It is encrypted according to the Data Encryption Stadard (DES) specified in. The decryption device 50 decrypts the encrypted packet using the corresponding encryption key provided by the decryption PID selection device 45 and the recording PID selection device 47 using known techniques. The decrypted packet from the decryption device 50 and the unencrypted packet from the decryption PID selection device 45 including the program for display are supplied to the decoder 55. The decrypted packet from the decryption device 50 and the unencrypted packet from the recording PID selection device 47 containing the program for recording are supplied to the MUX 110. The packet buffer 60 contains four packet buffers accessible by controller 115. One of these buffers will be allocated to hold the data that will be used by controller 115, and the other three buffers will be used by application devices 75, 80 and 85. It is assigned to hold the packets that are sent. Access to the packets stored in the four buffers in the packet buffer 60 by the controller 115 and the application interface 70 is controlled by the buffer controller 65. The decryption PID selection device 45 sends a destination flag to the buffer control device 65 for each packet identified by the decoding PID selection device 45 for decoding. These flags indicate the location of individual destinations in the packet buffer 60 for the identified packet and are stored by the buffer controller 65 in a table in internal memory. The buffer controller 65 determines a set of read and write pointers associated with the packets stored in the buffer 60, based on a first in, first out (FIFO) principle. The write pointer, in combination with the destination flag, sequentially moves the identified packets from the decryption PID selector 45 or the decryption device 50 to the next blank position in the proper destination buffer inside the packet buffer 60. Allows you to save. The read pointer allows the controller 115 and application interface 70 to sequentially read packets from the appropriate destination buffer in packet buffer 60. Unencrypted and decrypted packets supplied from the decryption PID selector 45 and the decryption device 50 to the decoder 55 are transported as specified in Section 2.4.3.2 of the MPEG system standard. Includes header. The decoder 55 determines from the transport header whether the unencrypted and decrypted packets contain adaptive fields (according to the MPEG system standard). Adaptation fields include timing information, such as the Program Clock Reference (PCR), which allows decoding and synchronization of content packets, for example. When a timing information packet, which is a packet containing an adaptive field, is detected, the decoder 55 informs the controller 115 that the packet has been received via an interrupt mechanism by setting a system interrupt. .. Further, the decoder 55 changes the timing packet transmission destination flag in the buffer control device 65, and supplies the packet to the packet buffer 60. By changing the destination flag of the buffer controller 65, the buffer controller 65 retains the timing information packets supplied by the decoder 55 to hold the data used by the controller 115 rather than the location of the application buffer. Divert to the buffer position of the allocated packet buffer 60. When the controller 115 receives the system interrupt set by the decoder 55, it reads the timing information and the PCR value and stores them in the internal memory. The PCR values of successive timing information packets are used by controller 115 to tune the system 25 master clock (27 MHz). The difference between the PCR-based estimate and the master clock-based estimate of the time interval between receiving continuous timing packets generated by controller 115 adjusts the system 25 master clock. Used for. To do this, controller 115 uses the resulting time estimate difference to adjust the input control voltage of the voltage controlled oscillator used to generate the master clock. The controller 115 resets the system interrupt after storing the timing information in the internal memory. Packets received by the decoder 55 from the decryption PID selector 45 and decryption device 50 that contain the program content, including audio, video, captions, and other information, are packets received from the decoder 55 by the buffer controller 65. -Sent to the buffer of the specified application device in the buffer 60. The application controller 70 sequentially extracts audio, video, captions, and other data from the designated buffer in the packet buffer 60 and supplies this data to the corresponding application devices 75,80,85. The application device consists of an audio decoder 80, a video decoder 85, and a high speed data port 75. Data port 75 is used, for example, to supply a computer with high-speed data such as a computer program. Alternatively, data port 75 is used, for example, to output data to an HDTV decoder. The packet containing the PSI information is recognized by the decryption PID selection device 45 as being sent to the buffer for the controller 115 in the packet buffer 60. The PSI packet is sent to this buffer by the buffer controller 65 via the decryption PID selection device 45, the decryption device 50 and the transport decoder 55, as described for the packet containing the program content. The controller 115 reads the PSI from the packet buffer 60 and stores it in internal memory. The controller 115 uses the process shown in FIG. 2 to generate compressed PSI (CPSI) from this stored PSI and packetize this CPSI suitable for storage on a selectable recording medium. Incorporate into the data stream. The packet identification and orientation process of FIG. 2 is performed by the decryption PID selection device 45 and the recording PID selection device 47 PID, destination and encryption key lookup table and buffer controller 65, as previously described. In collaboration with the function, it is dominated by the controller 115. The CPSI contains information related to the particular program to be stored, while the PSI contains information related to all programs in the data stream input to the transport system 25. Therefore, CPSI occupies less storage capacity and imposes less overhead than PSI. Also, given constant overhead constraints, CPSI is repeated in the data stream more often than PSI and is therefore retrieved and used to reduce the playback latency of the program content. The PSI specified in Section 2.4.4 of the MPEG System Standard consists of a table of four unencrypted elements or information. These tables are the Program Association Table (PAT), Program Map Table (PMT), Network Information Table (NIT), and Conditional Access Table (CAT). Each table is made up of data packets recognized by a particular PID. The PMT specifies PID labels that identify the individual packetized data streams that make up a program. These individual data streams are called basic streams in the MPEG standard. Basic streams include data streams for various languages, such as video, audio, and caption data streams. The PAT associates a PID with a program number that allows the identification and assembly of packets containing PMTs. NIT is optional and is configured and used to specify physical network parameters (eg, satellite transmission channel frequency, transponder channel, etc.). The CAT contains conditional access information, such as an encryption code that manages access to programs that depend on the user's credentials. In step 205 of FIG. 2, controller 115 (FIG. 1) performs an initialization procedure at system power-up following the start of step 200. In step 205, controller 115 applies the MPEG-specified PID values for the PAT and CAT tables (hexadecimal values 0000 and 0001 of PID, respectively) to the PID detection filter of the decoding PID selector 45 (Figure 1). Load. Further, the controller 115 allocates PAT packets and CAT packets in advance to the controller buffer in the packet buffer 60 by updating the destination table of the decryption PID selection device 45. The PAT packet and the CAT packet detected by the decryption PID selection device 45 are sent to the controller buffer in the packet buffer 60 via the decoder 55 under the control of the buffer control device 65. At step 205, the buffer controller 65 informs the controller 115 that the PSI packet is in the packet buffer 60 via a PSI interrupt. Upon receiving the PSI interrupt, the controller 115 repeatedly accesses the packets stored in the buffer of the specified packet buffer 60 and stores the complete CAT and PAT data in the internal memory. The controller 115 repeats this process to determine the PID that identifies the PMT and NIT packet from the PAT, and then stores the complete PMT and NIT data in internal memory. When the controller 115 continuously accesses the buffer 60 and receives the PSI interrupt while the receiver is activated, the controller 115 stores the PSI packet in the internal memory. As a result, controller 115 stores PAT, PMT, NIT and CAT data, including the complete PSI of the transport data stream input to system 25, in its internal memory. Data generated by the user (SP, SM) in step 210 of FIG. 2 identifying the program the user wants to store, the program stored in encrypted form, and the medium and device used for recording. , SE) is input to the controller 115 (Fig. 1). After selecting the on-screen menu using the remote control 125, the data selected by the user is input to the controller 115 via the interface 120. In step 215, in response to the input selection data (SP), controller 115 retrieves the PID for the program selected for storage from the stored PSI. The PID of the program to be stored is loaded by the controller 115 into the detection filter of the recording PID selection device 47. This allows the recording PID selection device 47 to identify the packet containing the program selected for recording. In step 215 of FIG. 2, the recording PID selector 47 (FIG. 1) feeds the unencrypted packet to the multiplexer (MUX) 110 and encrypts the encrypted packet (encryption in the packet header data). (Identified by the encryption index) is supplied to the decryption device 50 together with the associated encryption key. In step 215 of Figure 2, after the encryption key is generated by the smart card 130 (Figure 1) from the encryption code obtained from the CAT for the selected program (SP), as described earlier. Is supplied to the recording PID selection device 47. However, if the selected data SE requires encrypted storage, the recording PID selection device 47 sends the encrypted packet to be stored to the MUX110. As a result, in step 215 of FIG. 2, the packet containing the program (SP) to be stored is in either encrypted or decrypted format in response to the selected data SE. Is supplied to MUX110. In step 225, controller 115 compresses CPSI for the program (SP) selected for recording from full PSI (Program Specific Information) captured from the transport data stream input to system 25. Form (Condensed PSI: CPSI). Using the process shown in FIG. 3, controller 115 forms a CPSI for each program stored in step 225 of FIG. In step 305 of FIG. 3, following the start of step 300, the controller 115 changes the PID value of the basic stream that constitutes the program to be stored, and the PID value that distinguishes between PMT and NIT. Unless there is a coincidence, the modified PID value is different from the corresponding PID value played in the PSI of the transport data stream input to system 25. To determine the PID value to be changed, assign a fixed base PID to identify the PMT and add a given offset value to the base PID for video, audio, captions, PCR and NIT. Determine the PID value. Table 1 shows an exemplary PID assignment scheme for the two stored programs (Program 1 and Program 2). As you can see from Table 1, for these two programs, the corresponding basic streams are given the same PID value. For example, both Program 1 and Program 2 video streams are identified by PID = 0401. Assigning the same PID value to the corresponding basic stream simplifies the retrieval or reproduction of data performed by the decoder or playback device. The decoder directly identifies the stream without the need to first capture and assemble the PID de-mapping data. However, changing the PID number in this way creates ambiguity in the PID, so it is required that the basic streams with changed numbers that belong to different programs do not mix. If basic streams that share the same PID and belong to different programs are mixed, an error will occur in the assembly of the program. Therefore, changing the PID number in step 305 is used when several groups of basic streams belonging to different programs can be individually identified. Such cases include the generation of data streams and tape recording, in which the basic streams of the individual programs are not mixed. Also, as such a case, there is recording on a disk, and in this case, the recording information on the disk can be used to separate each group of basic streams belonging to individual programs. Alternatively, other PID assignment schemes that disambiguate PID can be used. For example, high-definition television (HDTV) signals in Section 8.4.7.1 of "Digital Television Standards for HDTV Transmission (April 21, 1995)" created by the US ATSC (Advanced Television Systems Committee). A base PID value is assigned to identify a particular program separately, as suggested for decryption of. Alternatively, the PID numbers of the basic streams that make up the program are recorded as if they were transmitted unchanged. Implementing such a scheme is easy, but it does not simplify the data retrieval process. Note that the PIDs that distinguish PAT and CAT are 0000 and 0001 (hexadecimal), respectively, as specified in the MPEG standard.<img file="JP4494530B2_D0001.tif" />In step 310 of FIG. 3, controller 115 creates a program association table (PAT) with a PID value (hexadecimal) of 0000. Advantageously, a PAT is created for only one currently stored program, and a new PAT is created for each stored program. Therefore, PAT is one program map Contains only the entries needed to identify the table (PMT). In the exemplary programs shown in Table 1, the CPSTs in Program 1 and Program 2 contain PATs and have a PID entry (0400) that identifies one PMT. Alternatively, the PAT may make an entry to identify the PMT for all programs selected by the user to store, or for all programs selected by the user to store in addition to the programs previously stored on the recording medium. Formed to include. To make the latter type of PAT, the controller 115 plays the pre-recorded PMT PID from the recording medium 105 via the recording interface 95 and the storage device 90, and then makes this PAT. When a NIT is created (described later), the PID that enables the identification of NIT packets is also included in this PAT. At step 315, controller 115 creates a PMT for each program it intends to store, using a given modified PID value to identify the basic stream of components. The basic stream containing the individual programs to be stored is determined by the controller 115 from the previously stored PSI data. At step 320, the controller 115 determines from the user input data SE supplied via interface 120 (FIG. 1) whether the individual programs are stored in encrypted form. If the program is stored in an unencrypted format, controller 115 continues execution from step 330 in Figure 3 and CAT (Conditional Access). Table: Conditional access table) is not created. If the SE data requires recording of an encrypted program, controller 115 creates a CAT for that program incorporating the encryption code in step 325. The stored encryption code is reproduced in the subsequent program search operation, and is used, for example, to generate an encryption key that enables decryption of the encrypted program for display. The encryption key is generated from the regenerated code only if allowed by the pre-stored entitlement data on the insertable smart card, as described above. The encryption system described here is only exemplary. It is also possible to use another encryption mechanism (mechanism) with a record of another encryption code or encryption key for decryption. Other entitlement mechanisms that do not involve sign recording do not necessarily require CAT. In addition, the need for CAT can be eliminated by incorporating the encryption code into the information table of CPSI other than CAT. For example, the encryption code is PMT CA<u style="single"></u>It can also be incorporated into the personal data part of the descriptor (according to MPEG System Standard Section 2.6.16). The advantage of this method is that it directly associates the code with the basic streams that make up the program, eliminating the need for a separate directory that links the basic stream to the code. Following step 325 or 320, in step 330, controller 115 uses the network information table NIT (NIT: Network Information) for each program it intends to store. Table). The NIT created by controller 115 contains personal data, such as program name, length, description, violence / sexual content rating, date and time when the program was recorded, and in addition. , Includes optional information (eg, whether the user can select the edited version). The stored personal data is inspected by the controller 115 from previously stored PSI information or, further, from data entered by the user via the remote control 125 and interface 120. NIT is optional and the user can also choose to omit NIT for any or all programs to be stored by menu selection. In that case, step 330 in FIG. 3 is ignored. Personal data may also be incorporated into CPSI information tables other than NIT. For example, personal data is PMT User Private It may be included in the descriptor part (according to MPEG system standard Section 2.6). The advantage of this method is that it directly associates the basic streams that make up the program with the personal data, eliminating the need for a separate directory to link the basic streams to the personal data. In step 335, the controller 115 assembles the PAT and PMT created for each program to form CPSI (Compressed Program Specifif Information) for each program. Controller 115 also assembles the optional CAT and NIT data created for each program into CPSI. Therefore, CPSI includes PAT and PMT, and also one or both of CAT and NIT. This created CPSI contains information related to a specific program selected to be stored from the data stream input to the system 25, and PSI (Program Specific Information) related to the program not selected to be stored. exclude. However, CPSI is also created for one or more programs selected to store from the input transport data stream. In that case, CPSI includes a single PAT and PMT, and may also include a single CAT and a single NIT. In this case, these tables contain data that supports the identification and playback of these multiple programs selected for storage, as specified by the MPEG standard. If a program is selected to store, for example, from two separate transport data streams input to system 25, its CPSI will be a single PAT and two PMTs (1 for each program being stored). Will contain PMT). The CPSI will also include one CAT and two NITs (one NIT for each program you are trying to save). Problems arise when the playback device improperly uses the CPSI of a different program when recovering a program from a recording medium. Unauthorized use of CPSI data (eg, PMT) can lead to errors in identifying and assembling data packets when restoring program content, resulting in invalid data, such as display or processing. Such problems occur, for example, when the regenerator does not use the CPSI of the regenerated program or continues to use the previously obtained CPSI for another program without noticing that the CPSI has changed. This is more likely to happen if the recording medium contains one or more programs. In that case, the playback device continues to use the CPSI of the previous program, for example, across program boundaries during a trick break or search operation. To alleviate the problem of using incorrect CPSI parameters across program boundaries, controller 115 formats CPSI in step 340 by using the process in Figure 4. In step 405 of FIG. 4, following the start of step 400, the controller 115 determines the type of storage device and recording medium selected by the user from the input data (SM) supplied via the interface 120. If the selected medium is a linear type, ie, a sequential access medium, such as a videotape used for digital VHS (DVHS), controller 115 performs step 410 followed by step 425. Is instructed to do so. At step 425, controller 115 changes the version number associated with the PAT, PMT, CAT, NIT packet format according to the MPEG syntax (MPEG system standard 2.4.4-2.4.4.11). The version number is changed by continuously increasing the version number during continuous repetition of CPSI in the program to be stored. The version number counter is continuously incremented throughout the overflow condition. When the program is taken out from the recording medium 105, the decoder or playback device detects continuous changes in the version number and uses PAT, MAT, PMT, CAT and NIT information each time it occurs in the taken out program. Another method can be used to change the version number and start the decoder to capture the CPSI again. The version number increases between the first two CPSIs that occur consecutively at the beginning of a program's recording, or between the occurrences of CPSIs selected within that program, or between different programs on the recording medium. Will be done. The version numbers that occur at the boundaries between different programs do not have to differ by a particular number. However, the successive version numbers created in a program must differ by only one in order to comply with MPEG. For applications that do not follow MPEG, the CPSI table version numbers differ by any value within a program. Another method used in step 425 is to specify a different indicator and send a command to the regenerator to use that CPSI each time a CPSI occurs or when a selected CPSI occurs. The assigned indicators are compatible with the MPEG system (syntax) and are located in the adaptive field of personal data parts, such as PAT or CAT (MPEG System Standard Section 2.4.3.4). The indicator is optional or is an existing indicator (specified in the MPEG system standard 2.4.3.5), for example, a'discontinuity indicator'in the packet header adaptation field. This discontinuity indicator is set to '1' and tells the decoder or playback device that the next PAT, PMT, CAT and NIT information should be used as there is potential discontinuity in CPSI. Instruct. This use of discontinuity indicators is not intended in the MPEG standard. For data streams that are incompatible with MPEG, yet another method is available, for example, specifying an indicator that is incompatible with MPEG, or using a signal that indicates the start or end of the program. Another technique configures the regenerator to identify and use any CPSI that occurs in the retrieved data stream, regardless of version number. In this case, step 425 is ignored. If the selected recording medium 105 is a non-linear type, i.e. a medium that supports non-sequential access, eg, a disk medium such as a CDROM or DVD, the controller 115 performs step 415 followed by step 430. You are instructed to do so. In non-linear type media, CPSI data is stored in one or more specific directory locations on the medium, or, like linear type media, inside the program content. In step 430, if CPSI is stored in the directory location, controller 115 changes the version number associated with the PAT, PMT, CAT, NIT packet in the directory location. The version number is incremented according to the MPEG system so that it differs between different programs on the recording medium 105 (Fig. 1). At step 430, if CPSI is stored inside the program content, controller 115 changes the version number as described in connection with step 425 for linear type media. To ensure that the version numbers of the CPSI elements are different between different programs, the controller 115 plays the pre-recorded program or file version numbers from the recording medium 105 via the recording interface 95 and the storage device 90. After that, create an increased version number and insert it in the CPSI data. There is another way to change the version number in step 430. However, the CPSI version number must be different between the different programs stored on the recording medium 105. Alternatively, when the program starts or crosses the boundaries of the program, step 430 specifies another indicator to send a command to the decoder to use CPSI. The assigned indicators are compatible with the MPEG system and are located in the adaptive field of the personal data part, eg PAT or CAT (MPEG System Standard Section 2.4.3.4). This metric is optional or is an extant metric such as the'discontinuity metric'in the packet header adaptation field, as mentioned in connection with step 425. For data streams that are incompatible with MPEG, an index is specified to send commands to the decoder or playback device to use CPSI. This indicator indicates, for example, the start or end of program recording. If the selected recording medium 105 is a solid state, ie, a semiconductor memory such as RAM, the controller 115 is instructed to perform step 420 followed by step 430. For solid-state media, like non-linear media, CPSI data is typically stored on one or more specific directory locations on the medium and is easily accessible from other storage locations. Therefore, the controller 115 mitigates the problem of using incorrect CPSI parameters across program boundaries by formatting CPSI for solid-state media as well as formatting CPSI for non-linear media. That is, controller 115 uses the process of step 430. The process of FIG. 4 ends at step 435, following step 425 or 430 to complete the CPSI formatting of step 340 of FIG. The process of FIG. 3 ends at step 345 of step 225 of FIG. 2, following step 340, which completes the formation of CPSI for the program chosen to be stored. Controller 115 continues the process of Figure 2 and performs step 230. At step 230, controller 115 formats the CPSI data into several sections according to the MPEG system (MPEG system standard, section 2.4.4.3-2.4.4.11). Sections are formed for PAT and PMT data. If these tables are incorporated into the CPSI in the process of Figure 3 above, sections will also be formed for the optional CAT and NIT (Personal Data). The resulting packetized data includes a table identifier, a section length identifier, and a version number previously determined in the process of Figure 4. Notably, the PAT section also contains a transport stream identifier that associates the PAT with a particular transport stream. Controller 115 obtains this identifier from the original PSI data and inserts it into the transport stream identification field of the PAT section of CPSI. However, this field can be left unchanged or left blank. At step 230, controller 115 adds the header data to the CPSI data section to format and packetize the CPSI data and insert it into the data stream to be stored. The controller 115 creates a header from the PSI header data stored in the controller 115's internal memory in accordance with MPEG system standards 2.4.3.2 and 2.4.3.3. However, CPSI section data differs in length from the corresponding PSI section data. Therefore, parameters including the'continuity count'and'pay load start' indicators are created by controller 115 and inserted into their respective indicator fields inside the header data. Will be done. The new continuity count index created by controller 115 represents, for example, the number of packets per PID of the corresponding CPSI element, rather than the number of packets per PID of the corresponding CPSI element. The new payload unit start index created by controller 115 identifies, for example, the first byte of the corresponding CPSI section instead of the first byte of the PSI section. In step 235 of FIG. 2, the CPSI in the form of packetized section data compatible with the MPEG formed in step 230 is supplied to the MUX 110 (FIG. 1) by the controller 115. As previously mentioned in connection with step 215, the program content packet data stream from the recording PID selection device 47 or the decryption device 50 is also supplied to the MUX 110. In step 235, the controller 115 uses the route selection signal C to multiplex the program content input to the MUX110 with the CPSI data stream to create a composite data stream output from the MUX110 to the recording interface 95. The composite data stream contains program content packets and CPSI packets. The controller 115 synchronizes the insertion of CPSI packets to be inserted into the program data stream to be stored in response to the PSI interrupt signal from the buffer controller 65 (FIG. 1). As mentioned in connection with step 205, the PSI interrupt indicates the presence of PSI packets in buffer 60. In this way, the packetized PAT, PMT, CAT and NIT sections of the CPSI are inserted at the PSI locations and replaced with the corresponding PSI sections. Unencrypted CPSI data can be inserted into the encrypted or unencrypted program content data stream that is input to the MUX110, creating an encrypted or unencrypted recording program. At step 235, controller 115 replaces each PSI data generated in the data stream it intends to store with the corresponding CPSI data, regardless of the type of medium the user has selected for recording. However, the coding overhead is further reduced by inserting the CPSI at the selected PSI position, or by inserting the CPSI only once in the program to be stored. The number of CPSI iterations in the program to be stored depends on several factors, such as the PSI element minimum iterations constraint, user preference, data storage capacity constraints, or the type of recording medium selected. Determined by 115. The method proposed by ATSC for High Definition Television (HDTV) specifies a minimum number of iterations for a PSI element, including a minimum interval of 100ms for PAT iterations (Digital Television Standard for HDTV Transmission,). Appendix C, Section 5.4, April 12, 1995). Further, for example, in a non-linear or solid-state recording medium, reducing the number of CPSI repetitions or inserting the CPSI only once in the stored program does not adversely affect the program playback waiting time. The reason is that these types of recording media allow rapid non-sequential (random) data access. At step 240, recording interface 95 receives from MUX110 a program stored in the form of a packetized data stream (hereinafter referred to as CPSI stream) incorporating CPSI. In Figure 2, the process used by controller 115 to generate the CPSI stream ends at step 245. Of note, in step 240, this CPSI stream is used not only for recording via recording interface 95, but also for display or communication via other applications, such as interface 70. The CPSI stream from the MUX110 is buffered at recording interface 95 to reduce gaps and bit rate fluctuations in its data. The buffered data is processed by the storage device 90 so as to be suitable for being stored in the recording medium 105. Controller 115 uses the standardized CEBus control protocol (Home Automation Standard (CEBus), EIA / IS-60, December 1989) to command storage device 90 (first) through I / O port 100. Initiate and control the operation of (Figure). The storage device 90 is a linear recording medium DVHS type device, using known error coding techniques such as channel coding, interleaving and Reed Solomon coding, and buffered data from the recording interface 95. The stream is encoded to produce an encoded data stream suitable for recording. The storage device 90 stores the resulting encoded data stream incorporating the CPSI on the tape medium 105. Other tape storage systems can record two data streams in parallel. The first data stream typically contains most of the program content and is traditionally stored helically on tape. The second data stream is typically stored linearly (non-helical) in parallel on an auxiliary track located towards the edge of the tape, which has a much lower data density and bit rate. In this type of storage system, the storage device 90 separates the CPSI data from the CPSI stream and stores the CPSI data in an auxiliary track. The storage device 90 stores the CPSI data so that each program recorded on the tape carries the associated CPSI data in the auxiliary track in parallel with the contents of the program. The number of repetitions of CPSI data in the auxiliary track is adjusted by the data rate constraint of the auxiliary track. Alternatively, the CPSI is stored in a helical auxiliary track, or in a data management area (area) that includes a Track Information Area (TIA) and an Insert and Track Information sector (ITI sector). .. The data management area is stored in a helical or non-helical track parallel to the program content. Although the storage device 90 has been described as a DVHS device that stores data in a linear type recording medium in the embodiment of FIG. 1, any type of storage device may be used. For example, the storage device 90 may be a solid state or non-linear type device that stores data in RAM or DVD or CDROM. If the storage device 90 and the recording medium 105 are of non-linear or solid state type, the storage device 90 separates the CPSI data from the CPSI stream and stores the CPSI data in a designated directory area of the recording medium. This is advantageous because it avoids repeated CPSI recordings and reduces the required storage capacity. Alternatively, the storage device 90 stores a CPSI stream (formed and input to the storage device 90) in which the CPSI data is repeated two or more times. In addition, the transport system 25 of FIG. 1 can also incorporate multiple storage / regeneration paths that support the operation of multiple storage devices of various types, including linear, non-linear and solid state. The single recording / playback path shown in FIG. 1 consists of devices 47,90,95,105,110, as described above. By overlapping these elements to produce parallel storage functions, the system 25 is easily extended to incorporate multiple storage paths. The storage path and program scheduled for a particular storage device is entered into the controller 115 via interface 120 by selecting the on-screen menu on the remote control 125, as previously mentioned, by the user. It is selected according to the generated data (SP, SM). The system 25 of FIG. 1 uses the process of FIG. 5 to reproduce the program from the storage device 90 and the medium 105 in playback mode. The regenerated data stream is processed by system 25 and fed to application devices 75, 80 and 85 for display or output. Alternatively, the program data stream is stored in another parallel storage device (not shown in Figure 1 for simplification of the drawing). In FIG. 5, in step 505 following the start of step 500, the data (SR, SM) generated by the user is a system 25 that identifies the program to be reproduced and the storage device for reproducing the program 25 (FIG. 1). ) Is input to the controller 115. The user selection data is input to the controller 115 via the interface 120 using the remote control 125 following the selection of the on-screen menu. For illustrative purposes, it is assumed that the program played from storage device 90 (FIG. 1) is of the user's choice. In step 510, as previously mentioned, controller 115 uses a standardized CEBus control protocol and is a program data stream selected by storage device 90 from recording medium 105 by command via I / O port 100. Start playing. The storage device 90 decodes the erroneously encoded data retrieved from the medium 105 and reproduces the corresponding data initially supplied to the storage device 90 for storage. The storage device 90 is a DVHS linear type storage device or another type of storage device, for example, a solid state RAM or a non-linear DVD or CDROM type device. In step 510, the decrypted and reproduced data stream is transferred to the recording interface 95 via the storage device 90. This data transfer is controlled and synchronized by controller 115 via standard CEBus. The recording interface 95 buffers the data received from the storage device 90, adjusts the time interval between data packets, and produces a buffered data output that is compatible with MPEG and subject to MPEG bit rate constraints. At step 515, the controller 115 uses the path selection signal C to send the buffered output (playback data stream) from the recording interface 95 to the PID selection device 45 and the recording PID selection device 47 via the MUX 37. .. At step 520, the decryption PID selector 45 and the recording PID selector 47 and the rest of the system 25 process the playback data stream for storage through the MUX110 or for the application via interface 70. .. The playback data stream from the recording interface 95 and the data stream transmitted from the selector 35 are similarly processed by the system 25 following selection via MUX37. All of these data streams are processed in the manner previously described for the data stream being transmitted. However, the playback data stream selected via MUX37 already incorporates CPSI. Therefore, in playback mode, controller 115 does not perform in step 520 the steps related to the formation of CPSI described in connection with FIGS. 2-4. In the exemplary playback mode shown in FIG. 5, system 25 transport-decodes the playback data stream and feeds the decoded data to application decoders 80 and 85 for display. In this mode, system 25 uses the CPSI data contained in the playback data stream according to the MPEG standard to provide a transport-decoded data stream that represents the selected program SR. At step 520, controller 115 accesses the playback data stream CPSI data through buffer 60 and inspects the data for changes in version numbers between successive CPSI elements. The controller 115 also checks the playback data stream for the discontinuity indicated by the'discontinuity index'in the packet header adaptation field (as specified in 2.4.3.5 of the MPEG system standard). When a version number change or discontinuity is detected, controller 115 uses the latest complete CPSI data for transport decryption of the playback data stream. Controller 115 also uses up-to-date complete CPSI data based on various other conditions, such as transport error indications and detection of continuity count discrepancies between consecutive packets of a particular PID. Is programmed. Both of these parameters are present in the playback data stream packet header (as specified in Section 2.4.3.2 of the MPEG system standard). Controller 115 should also use CPSI, which detects discontinuities between presentation time stamps (PTSs) or decoding time stamps (DTSs) specified by the MPEG standard or other user-specified time stamps. Programmed in. However, in a system compatible with MPEG, the discontinuity index is required to be set to indicate the occurrence of a discontinuity count value. Transport decryption of the playback data stream using PID filters 45 and 47, decryption device 50, decoder 55, buffer 60, and buffer controller 65, as previously described for FIG. This CPSI is used when doing so. The transport-decoded data stream (excluding CPSI) is supplied to the application decoders 80 and 85 for MPEG decoding and image reproduction via the interface 70. In another mode, system 25 feeds a playback data stream incorporating CPSI to another application device (eg, high speed data port 75). CPSI can then be used to transport-decrypt the playback data stream with these application devices or subsequent devices as needed. If the playback data stream is stored, for example, in a second storage device other than storage device 90, the MUX110 will store the data stream incorporating CPSI in that second storage device via a second recording interface. Supply to the device. Further, this second device and interface (neither shown in FIG. 1) mimics the operation and function of the storage device 90 and the recording interface 95, respectively. During the default period, system 25 sends the decoded data representing a given image for display, such as a'blue screen'or'freeze frame', to the video decoder 85 before using CPSI. Supply. Similarly, during the default period, system 25 feeds the audio decoder 80 to erase the audio output before detecting the version number change and using CPSI. These measures prevent annoying video / audio output to the playback device until the correct CPSI data is used and a valid material for viewing is supplied. The default period includes the period from one of the following states until a change in the version number of the CPSI element is detected: a) Detection of program indicators or end of system boot; b) Detection of user commands with fast forward or skip (trick play); or c) False condition detection indicating that no valid video packet has been detected. The data from interface 70, MPEG-decoded by the application decoders 80 and 85, is displayed through the audio and image playback devices within the decoders 80 and 85, respectively. This completes the playback process that ends in step 530. It should be noted that controller 115 can substitute any of the other methods mentioned above to prevent the use of incorrect CPSI data. The architecture in Figure 1 is not unique. Other architectures can be obtained according to the principles of the invention to achieve the same object. In addition, the functions of the architectural elements of Figure 1 and the processing steps of Figures 2-5 can be performed in whole or in part within the programmed instructions of the microprocessor. .. Also, the principles of the invention apply to any form of electronic program guide that is incompatible with MPEG, and the principles of the invention are not limited to those transmitted in a PSI table compatible with MPEG. ..