MXPA98009922A - Data formats in packages for a digita data storage environment - Google Patents

Abstract

The present invention relates to a storage medium format for a storage medium 8105) that contains packet data programs, including packet identifiers (PIDS) that identify data streams in individual packets that constitute a program. The data format facilitates the association and assembly of data currents in program packages, by means of a decoder, independent of the PID demapping data. The PIDS include a base PID to identify a data stream, and a second PID of a previously determined value determined with the base PID, to identify a second data stream. The data streams in corresponding packets that constitute different programs receive the same PID (115). The storage media format can also include program-specific information (PSI) suitable for use in retrieving the data content of a program. The PSI includes a map table of the MPEG-type program (PMT), and an MPEG-type program association table (PAT), and incorporates a suitable parameter for ordering a decoder (25) that applies the PSI in the decoding of the program, regardless of the content of the previous PSI. In addition, the PSI may incorporate a version number that varies between successive PSI submissions, regardless of the substantive change in the content of the PSI. You can also include one or more private data elements in the PMT, to describe the program

Description

DATA FORMATS IN PACKAGES FOR A DIGITAL DATA STORAGE ENVIRONMENT This invention relates to the field of digital signal processing, and more particularly, to the formation of Program-specific Information used to retrieve the content of the program and the insertion of the information into digital video data for storage, for example. In video processing and storage applications, digital video data is typically encoded to conform to the requirements of a known standard. A standard widely adopted is the MPEG2 image coding standard (Expert Group on Moving Images), hereinafter referred to as the "MPEG Standard". The MPEG standard is comprised of a coding section of the system (ISO / IEC 13818-1, June 10, 1994), and a video coding section (ISO / IEC 13818-2, January 20, 1995), referred to later in the present as the "MPEG system standard" and "MPEG video standard", respectively. The video data encoded in the MPEG standard is in the form of a packet data stream, which normally includes the data content of many program channels (for example, channels 1-125). In order for a decoder to decode the packet data stream, and retrieve the video data content of the channels of selected programs for visual display, for example, individual packages that comprise the selected program channels must be identified and assembled. The MPEG standard defines the Specific Information of the Program (PSI) to be used in the identification and assembly of individual data packets, in order to recover the content of the selected program channels. The PSI includes both user-definable and mandatory information elements, and is defined by including sufficient information to retrieve the data content of all program channels that comprise the packet data stream. In addition, the PSI is incorporated into the packet data stream. This increases the storage capacity required to store the data stream, as well as reduces the bandwidth of communication available for communication of program content. As such, the PSI represents a surplus of additional coding. The degree of surplus imposed by the PSI depends on the amount of data contained in the PSI (size of the PSI), and the repetition frequency of the PSI within the packet data stream. At a minimum, the PSI needs to contain enough information to retrieve the data content of all the program channels that comprise the packet data stream. The minimum repetition frequency of the PSI in the packet data stream is limited by the operational delay characteristics of the desired system, for example, a decoder requires an updated PSI to implement a program channel change ordered by television viewer. Consequently, the minimum PSI repetition frequency is limited by the desire of a television viewer to tolerate the delay (latency) in response to a channel command change. These problems are solved by a system in accordance with the present invention. Hereby, the inventors have recognized that, in some applications it is desirable to reduce the surplus imposed by the PSI. In a limited capacity digital storage application, for example, it is convenient to reduce the size of the PSI stored in the storage medium, and the number of times the PSI is repeated in the storage medium. In other video processing applications, it is desirable to reduce the size of the PSI to allow a more frequent repetition of the PSI and thereby reduce the latency of retrieving the content of the program. In addition, the generated PSI must be compatible with the operating characteristics of the selected storage medium, and the user's requirements. The inventors have further recognized that it is desirable to store the PSI in the storage medium, in a format that minimizes the misuse of the PSI of a program, for the recovery of the content of a second program that requires different recovery parameters. This situation can arise when the storage medium is used to store programs derived from different streams of data in packets, for example, when the storage medium is partially overwritten with a program derived from a different data stream. Ideally, the storage format of the PSI would also reduce the latency of program recovery, and would minimize the times of random access data retrieval. Rapid random access is particularly important in those operations of the storage device that involve fast playback or fast content skipping (trick play), such as in a VCR, for example. In accordance with the principles of the present invention, a video processing system reduces the processing and storage overhead imposed by the Program Specific Information (PSI) used for the recovery of program content. An disclosed system provides the condensed PSI, and adaptively inserts the condensed PSI into a packet data stream to provide a reduced processing and storage surplus. The system generates in an adaptable way the PSI for different types of media, for example, videotape, digital video disc (DVD), or CDROM. In addition, storage media formats and packet data stream formats are disclosed, which provide greater data processing efficiency using the condensed PSI. The disclosed data storage and stream formats provide reduced program recovery latency, and minimize the use of incorrect PSI parameters across the boundaries of the program. A storage medium format for a storage medium containing a plurality of packet data programs, includes packet identifiers (PIDs), which identify the data streams in individual packets that constitute a program. The data format facilitates the association and assembly of data streams in packets of the program by means of a decoder, independent of the PID demapping data. The PIDs include a base PID to identify a data stream, and a second PID of a predefined value previously determined with the base PID, to identify a second data stream. To the data streams in corresponding packets that constitute different programs, they are given the same PID. Another format of storage medium for a storage medium containing a data program in packages, includes program-specific information (PSI) suitable for use in the recovery of the program's data content. The PSI includes a program map table (PMT), which associates the packet identifiers (PIDs) with data streams in individual packets that make up the program. The PSI also includes a program association table (PAT) that associates the program with the PIDs that identify the packages that comprise the PMT. The PSI incorporates a suitable parameter to order a decoder to apply the PSI in the decoding of the program, regardless of the previous content of the PSI. In a feature of the invention, a version number is incorporated in the stored PSI, to distinguish between different versions of the PSI, and the version number is varied between successive PSI presentations, regardless of the substantive change in the content of the PSI. the PSI between the successive presentations. In a further feature of the invention, one or more private data elements are included in the stored PMT, which describe the program. The data items are selected from title, duration, program description, violence evaluation, property evaluation for age, recording time, recording date, and version list.

Brief Description of the Drawings In the drawing: Figure 1 shows a video receiver system, according to the invention, for generating in an adaptive manner and inserting the condensed PSI in a packet data stream, to be stored in different types of medium. Figure 2 shows a flow diagram for a process to generate the condensed program specific information (CPSI) from the PSI, and to incorporate the CPSI into a packet data stream suitable for storage in a selectable storage medium. Figure 3 shows a flow chart for a process to form the CPSI for the storage of selected programs in a selected storage medium. Figure 4 shows a flow diagram for a process to format the CPSI, in order to ensure that the correct CPSI is applied during the decoding of the program. Figure 5 shows a flow chart for a process to retrieve selected programs from a selected storage device.

Figure 1 shows a video receiver system, in accordance with the invention, for generating in a manner adaptive, and insert condensed PSI into a packet data stream to be stored, for example. The receiver system generates in an adaptive way the PSI for different types of media, for example videotape, digital video disc (DVD), or CDROM. In addition, the video receiver system reduces the processing and storage surplus imposed by the Program Specific Information (PSI) used to recover the content of the program. Although the disclosed system is described in the context of an MPEG compatible system for receiving transport streams encoded in MPEG that represent transmission programs, it is only an example. The principles of the invention can also be applied to other types of systems, including systems not compatible with MPEG, that involve other types of coded data streams. For example, the principles of the invention can be applied to digital video disc (DVD) systems, and to MPEG program streams. In addition, although the system disclosed is described as processing transmission programs, this example only. The term 'program' is used to represent any form of data in packets, such as telephone messages, computer programs, Internet data, or other communications, for example. In one scenario, in the video receiver system of Figure 1, a modulated carrier is received with data from video by the antenna 10, and processed by the unit 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 the commands from the remote control unit 125. The system 25 provides compressed data outputs for storage, additional decoding, or communication to other devices. A user of the video receiver selects the program he wishes to view, the programs he wishes to store, the type of storage medium, and the storage mode, by selecting the on-screen menu, using the remote control unit 125. The decoders of video and audio 85 and 80, respectively, decode the compressed data from the system 25, to provide outputs for visual display. The data port 75 provides an interface for the communication of the compressed data from the system 25 to other devices, such as a computer or a High Definition Television (HDTV) receiver, for example. The storage device 90 stores the compressed data from the system 25 in the storage medium 105. The device 90, in a reproduction mode, also supports the recovery of the compressed data from the storage medium 105, to be processed by the system 25 for decoding, its communication to other devices, or its storage in a different storage medium (not shown to simplify the drawing). Considering Figure 1 in detail, a modulated carrier with video data received by the antenna 10, is converted to a digital form, and. it is processed by the input processor 15. The processing 15 includes the radio frequency (RF) tuner, and the intermediate frequency (IF) mixer, and the amplification stages to convert the input video signal down to a band. of lower frequency suitable for other processing. 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 is provided , by means of the selector 35, with the output from the decoder 30, or the output of the decoder 30 is further processed by the demixing unit of NRSS (National Renewable Standards Committee). The selector 35 detects the presence of a NRSS-compatible insertable demixing card, and provides output from the unit 40 to the multiplexer 37 only if the card is currently inserted in the video receiving unit (the NRSS removable conditional access system is defined in FIG. Project Document EIA IS-679, Project PN-3639). Otherwise, the selector 35 provides the output from the decoder 30 to the multiplexer 37. The presence of the insertable card allows the unit 40 to demix the additional main program channels, for example, and provides additional program services to a viewer. . It should be noted that, in the preferred embodiment, the NRSS unit 40 and the smart card unit 130 (the smart card unit 130 discussed below) share the same interface of the system 25, so that only one card can be inserted. NRSS or one smart card at a time. However, the interfaces can also be separated to allow a parallel operation. The data provided to the multiplexer 37 from the selector 35 is in the form of a packet transport data stream that complies with MPEG, as defined in the MPEG 2.4 system standards section, and includes the data content of one or more program channels. Individual packets comprising channels of particular programs are identified by Packet Identifiers (PIDs). The transport stream contains the Program Specific Information (PSI), to be used in the identification of the PIDs, and to assemble the individual data packets, in order to recover the content of all the program channels that contain the current of data in packages. A user of the video receiver selects the program he wishes to view, the programs he wishes to store, and the means to be used for storage by a selection of the on-screen menu, using the remote control unit 125. The system controller 115 uses the selection information, provided by means of interface 120, to configure the system 25, in order to select the programs for storage and visual display, and to generate the appropriate PSI for the device and storage medium selected. The controller 115 configures the elements 45, 47, 50, 55, 65, and 95 of the system 25, establishing control register values within these elements, by means of a data bus, and by selecting signal paths by means of the multiplexers 37 and 110 with the control signal C. In response to the control signal C, the multiplexer 37 selects the transport stream from the unit 35, or in a reproduction mode, a data stream recovered from the storage device 90 by means of the storage interface 95. In the normal non-reproducing operation, the data packets comprising the program that the user selected to see are identified by their PIDs, by means of the selection unit 45. If a cryptic encoding indicator in the header data of the selected program packages indicates that the packets are cryptically encoded, the unit 45 provides the packets to the cryptic decoding unit 50. Otherwise, the unit 45 provides the non-encrypted packets cryptically to the transport decoder 55. In a similar manner, the data packets comprising the programs that the user is selected for storage, they are identified by their PIDs, through the selection unit 47. The unit 47 provides the cryptically encoded packets to the cryptic decoding unit 50, or the packets not cryptically encoded to the multiplexer 110, based on the information of the cryptic encoding flag of the packet header. The units 45 and 47 employ PID detection filters that couple the PIDs of the input packets provided by the multiplexer 37, with the PID values previously loaded in the control registers inside the units 45 and 47, by the controller 115 The previously loaded PIDs are used in units 47 and 45 to identify the data packets to be stored, and the data packets to be decoded for use in order to provide a video image. Previously loaded PIDs are stored in look-up tables in units 45 and 47. The PID look-up table is mapped in memory, in the cryptic encoding key tables, in units 45 and 47, which associate the keys of coding cryptic with each PID previously loaded. The PID mapped in memory, and cryptic encoding key query tables, allow units 45 and 47 to couple cryptically encoded packets containing a previously loaded PID, with the associated cryptic encoding keys that allow their cryptic decoding. Uncoded packets cryptically have no associated cryptic encoding keys. The units 45 and 47 provide both the identified packets and their cryptic encoding keys associated with the cryptic decoder 50. The PID lookup table in unit 45 is also mapped in memory, in a destination table that couples the packets containing PIDs previously loaded, with corresponding destination buffer zone locations, in the packet buffer zone 60. The cryptic encoding keys and the destination buffer location addresses associated with the programs selected by a user to view or store, is preloaded in units 45 and 47, together with the assigned PIDs, by means of the controller 115. The cryptic encoding keys are generated by the smart card system 130 which complies with ISO 7816-3, from the cryptic encoding codes extracted from the input data stream. The generation of cryptic encoding keys is subject to the client's right determined from the previously encoded information stored in the same insertable smart card (ISO 7816-3 International Standards Organization document of 1989, defines the interface and signal structures for a smart card system). The packets provided by units 45 and 47 to unit 50 are cryptically encoded in accordance with the Cryptographic Data Coding Standard (DES) defined in Publications 46, 74, and 81 of the Federal Information Standards (FIPS), provided by the National Technical Information Service, Department of Commerce. The unit 50 cryptically decodes the cryptically encoded packets, using corresponding cryptic encoding keys provided by the units 45 and 47, by the application of known techniques. The packets cryptically decoded from the unit 50, and the packets not cryptically encoded from the unit 45 comprising the program for visual display, are provided to the decoder 55. The packets decoded cryptically from the unit 50, and the packets not encoded cryptically from the unit 47 comprising the program for storage, are provided to multiplexer 110. Unit 60 contains 4 buffer zones of packets accessible by controller 115. One of buffer zones is allocated to contain data. intended to be used by the controller 115, and the other three buffer zones are allocated to contain packets that are intended to be used by the application devices 75, 80, and 85. Access to the packets stored in the four zones of buffer in the unit 60, both by the controller 115 and by the application interface 70, is controlled by the buffer zone control unit 65. The unit 45 provides a destination indicator to the unit 65 for each packet identified by unit 45 for decoding. The indicators indicate the individual destination locations of the unit 60 for the identified packets, and are stored by the control unit 65 in an internal memory table. The control unit 65 determines a series of read and write pointers associated with the packets stored in the buffer zone 60, based on the First-Enter-First-Exit (FIFO) principle. The write pointers, in conjunction with the destination indicators, allow sequential storage of a packet identified from units 45 or 50, at the next empty location within the appropriate destination buffer zone in unit 60. read flags allow sequential reading of the packets from the target buffer areas of the appropriate unit 60, by means of the controller 115 and the interface of application 70. The crypto-encoded and decoded packets cryptically provided by the units 45 and 50 to the decoder 55, contain a transport header, as defined by section 2.4.3.2 of the standard MPEG systems. The decoder 55 determines, from the transport header, whether the packets not cryptically encoded and decoded cryptically contain an adaptation field (according to the MPEG system standard) The adaptation field contains the time information, including, References Program Clock (PCRs) that allow the synchronization and decoding of the content packets On the detection of a time information packet, that is, a packet containing an adaptation field, the decoder 55 points to the controller 115 by means of of an interruption mechanism, by setting a system interrupt, that the packet has been received In addition, the decoder 55 changes the destination indicator of the time packet in the unit 65, and provides the packet to the unit 60 When changing the destination indicator of unit 65, unit 65 bypasses the provided time information packet by the decoder 55 to the location of the buffer zone of the unit 60 assigned to contain the data to be used by the controller 115, instead of a Location of application buffer zone. Upon receiving the interrupt establishment of the system by the decoder 55, the controller 115 reads the time information and the PCR value, and stores it in the internal memory. The PCR values of the successive time information packets are used by the controller 115 to adjust the master clock of the system 25 (27 MHz). The difference between the PCR-based and master-clock-based estimates of the time interval between receipt of the successive time packets, generated by the controller 115, is used to adjust the master clock of the system 25. The controller 115 achieves this by applying the derivative time estimate difference to adjust the input control voltage of a controlled voltage oscillator used to generate the master clock. The controller 115 restores the system interruption after storing the time information in the internal memory. The packets received by the decoder 55 from the units 45 and 50 containing the content of the program, including audio, video, subtitling, and other information, are routed via the unit 65 from the decoder 55 to the buffer areas of the device. designated application in the packet buffer zone 60. The application control unit 70 recovers in sequence the audio, video, subtitling, and other data from the buffer areas designated in the buffer zone 60, and provides the data to the corresponding application devices 75, 80, and 85. The application devices comprise audio decoders and video 80 and 85, and the high-speed data port 75. The data port 75 can be used to provide high-speed data, such as computer programs, for example, to a computer. Alternatively, port 75 can be used to produce data to a high definition television decoder, for example. The packets containing PSI information are recognized by the unit 45, as they are intended for the buffer zone of the controller 115 in the unit 60. The PSI packets are directed towards this buffer area by the unit 65 by the units 45, 50, and 55 in a manner similar to that described for packages containing the content of the program. The controller 115 reads the PSI from the unit 60 and stores it in the internal memory. The controller 115 employs the process of Figure 2, both to generate the condensed PSI (CPSI) from this stored PSI, and to incorporate the CPSI into a packet data stream suitable for storage in a selectable storage medium. The packet identification and address process of Figure 2 is regulated by the controller 115 in conjunction with the unit 45, and the PID lookup tables, destination and cryptic encoding keys of the unit 47, and the control unit 65 operates in the manner previously described. The CPSI contains information related to the particular program to be stored, while the PSI contains information related to all the programs in the data stream entry to the system 25. Consequently, the CPSI occupies less storage capacity, and imposes less surplus than the PSI. In addition, given a fixed surplus limitation, the CPSI can be repeated in a data stream more frequently than the PSI, and in this way, can be derived and applied to reduce the latency of recovery of the program content. PSI, as defined in the MPEG 2.4.4 system standards section, comprises four cryptic non-encoded elements or information tables. These are the Table of Program Association (PAT), the Program Map Table (PMT), the Network Information Table (NIT), and the Conditional Access Table (CAT). Each table is formed of data packets that are recognized by a particular PID. The PMT defines the PID tags that identify the data streams in individual packets that make up a program. These individual streams are denoted elementary streams in the MPEG standard. The elementary currents include currents of data such as video data streams, audio for different languages, and subtitling. The PAT associates a program number with the PIDs that allow the identification and assembly of the packages comprising the PMT. The NIT is optional, and can be structured and used to define the physical parameters of the network, such as the frequencies of the satellite transmission channels, and the transponder channels, for example. The CAT contains conditional access information, such as the cryptic encoding codes that regulate access to programs that depend on the user's right. In step 205 of Figure 2, the controller 115 (Figure 1) performs an initialization procedure to energize the system following the start in step 200. In step 205, the controller 115 loads the PID detection filters of unit 45 (Figure 1) with the PID values defined by MPEG for the PAT and CAT tables (hexadecimal value of PIDs 0000 and hexadecimal value 0001, respectively). In addition, the controller 115 pre-allocates the PAT and CAT packets to the controller buffer area in the unit 60, updating the destination table of the unit 45. The PAT and CAT packets detected by the unit 45 are addressed by means of the decoder 55 to the buffer zone of the controller in the unit 60 under the control of the unit 65.

In step 205, the control unit 65 signals the controller 115 by means of a PSI interrupt, that there are PSI packets present in the unit 60. The controller 115, upon receiving the PSI interrupt, gives repeated access to the stored packets. in its designated buffer area in unit 60, and stores the complete CAT and PAT data in the internal memory. The controller 115 repeats this process to store the complete PMT and NIT data in the internal memory after determining the PIDs that identify the PMT and NIT packets from the PAT. The controller 115 continuously accesses the buffer zone 60, and captures the PSI packets in the internal memory upon receipt of the PSI interrupts, while the receiver is energized. As a result, the controller 115 captures, in its internal memory, the PAT, PMT, NIT, and CAT data comprising the complete PSI of the input of the transport data stream to the system 25. In step 210 of the Figure 2, the data generated by the user (SP, SM, SE), which identifies the programs that a user wishes to store, as well as those programs that are to be stored in a cryptically encoded form, and the medium and device that are going to be stored. use for storage, they get into the controller 115 (Figure 1). The data selected by the user is entered into the controller 115 by means of the interface 120 following the selection of the on-screen menu with the remote control unit 125. In step 215, in response to the input selection data (SP), the controller 115 derives the PIDs for the selected programs, to be stored from the stored PSI. The detection filters of the unit 47 are loaded with the PIDs of the programs that are to be stored by the controller 115. This makes it possible for the unit 47 to identify the packets comprising the programs selected for storage. In step 215 of Figure 2, unit 47 (Figure 1) provides crypto-encoded packets to multiplexer 110, and provides crypto-encoded packets (identified by a cryptic encoding flag in the packet header data), together with associated cryptic encoding keys, to the cryptic decoding unit 50. The cryptic encoding keys are provided to the unit 47 by the controller 115 in step 215 of FIG. 2, following its generation by the smart card 130 (FIG. 1), from the cryptic encoding codes from the CAT for the selected programs (SP), in the manner described above. However, if the SE of the selection data requests a crypto-encoded storage, the unit 47 passes the crypto-encoded packets to be stored to the multiplexer 110. Accordingly, in step 215 of Figure 2, the packets comprising the programs that they go to store (SP) are provided to the multiplexer 110, either in a cryptically encoded or cryptically decoded form, in response to the SE selection data. The controller 115, in step 225, forms the condensed program specific information (CPSI) for the programs selected to be stored (SP) from the specific information of the complete program (PSI) captured from the input of the data stream of transport to the system 25. The controller 115 forms the CPSI for each program to be stored in step 225 of Figure 2, using the process shown in Figure 3. In step 305 of Figure 3, following the start in step 300, the controller 115 renumbers the PID values of the elementary streams that constitute the programs to be stored, as well as the PIDs that identify the PMT and NIT. Except in the case of a random match, the renumbered PID values are different from the corresponding PID values retrieved in the PSI of the input of the transport data stream to the system 25. The renumbered PIDs are determined by the assignment of a fixed PID (base) to identify the PMT, and adding predefined values previously determined to the base PID to determine the PID values for video, audio, subtitling, PCR and NIT.

Table I shows an example PID assignment scheme for two programs to be stored (program 1 and program 2). As can be seen in Table I, the corresponding elementary streams for the two programs are given the same PID, for example, the video streams for programs 1 and 2 are both identified by PID = 0401. The assignment of the same PID values to the corresponding elementary streams simplifies data recovery and the recovery process performed by a decoder or a playback device. A decoder can directly identify the streams without the need to first capture and assemble the PID demapping data. However, the renumbering of the PIDs in this way introduces an ambiguity of potential PID, and requires that the renumbered elementary streams belonging to the individual programs are not intermixed. Otherwise, the intermixing of the elementary streams, which they share in the same PID, which belong to different programs, can result in an erroneous assembly of the program. Consequently, the PID renumbering of step 305 is used in applications where the groups of elementary streams belonging to individual programs can be separately identified. These applications include the generation of data stream and tape storage, where elementary streams from individual programs do not intermix. These Applications also include disk storage applications, where disk storage information is available to separate groups of elementary streams belonging to individual programs. 5 Alternatively, other PID mapping schemes that avoid potential PID ambiguity can be used. For example, you can assign the base PID value to identify particular programs separately, as proposed for the decoding of television signal '^ 10 high definition (HDTV) in section 8.4.7.1 of the Digi tal Television Standard for HDTV Transmissio (Standard for Digital Television for High Definition Television Broadcasting) of April 12, 1995, prepared by the Systems Committee of Advanced Television of the United States (ATSC). 15 In an alternative way, the PID values of the elementary streams that constitute the programs can be stored ? k how they are transmitted, if they are renumbered. This scheme is direct to be implemented, but it does not simplify the data recovery process. Notice that the PIDs that identify PT and CAT are 0000 and 0001 (in hexadecimal) respectively, as defined in the MPEG standard.

Table I In step 310 of Figure 3, the controller 115 creates a program association table (PAT) with a PID value (in hexadecimal) equal to 0000. The PAT is conveniently created only for the individual program currently being stored. , and a new PAT is created for each stored program. Accordingly, the PAT contains only entries that are required for the identification of a single program map table (PMT). In the programs of As shown in Table I, the CPSI of both program 1 and program 2 would contain a PAT with a PID entry (0400) that identifies a single PMT. Alternatively, the PAT can be formed to contain entries for the identification of a PMT, either for all the programs that the user has selected to store, or for all the programs that the user has selected to select more those previously stored in the program. the storage medium. In order to create the last type of PAT, the controller 115 recovers the PIDs of the previously recorded PMTs, from the storage medium 105, via the interface 95 and the device 90, before creating the PAT. If an NIT is created, as discussed below, the PID that allows the identification of the NIT packets in the PAT is also included. In step 315, the controller 115 creates a PMT for each program to be stored, using the previously determined renumbering determined values, to identify the elementary streams of components. The elementary streams comprising the individual programs to be stored are determined by the controller 115 from the previously stored PSI data. Step 320, the controller 115 determines from the SE of user input data provided by the interface unit 120 (Figure 1), whether the individual programs are going to store or not in a cryptically encoded form. If a program is to be stored in a non-crypted form, the controller 115 continues execution from step 330 of Figure 3, and does not create a conditional access table (CAT). If the data is requested to crypto-encoded storage of a program, the controller 115, in step 325, creates a CAT for the program, which incorporates a cryptic encoding code. The stored coding code is recovered in a subsequent program recovery operation, and used to generate a cryptic encoding key that allows cryptic decoding of the cryptically encoded program for visual display, for example. The cryptic encoding key can only be generated from the retrieved code, if allowed by the rights data previously stored in a smart card insertable in the manner discussed above. The cryptic coding system described is exemplary only. Alternative cryptic encoding mechanisms may be employed that involve storing different codes or cryptic encoding keys for cryptic decoding. Other rights mechanisms that do not involve code storage do not necessarily require a CAT. In addition, cryptic encoding codes can be incorporated into the information tables of the CPSI, which is not a CAT, thus eliminating the need for a CAT. For example, cryptic encoding codes can be incorporated into the private data section CA_descriptor of the PMT (according to the MPEG system standards section 2.6.16). This approach has the advantage of associating the codes directly with the elementary streams that constitute the programs, avoiding the need for a separate directory to link the elementary streams with the codes. Following step 325 or 320, controller 115, in step 330, creates a network information table (NIT) for each program to be stored. The NIT created by the controller 115 includes private data that may include, for example, a title, duration and description of the program, as well as an evaluation of violence / sex content, and a time and date in which it is recorded, plus the Additional optional information, such as if the user can select edited versions. The stored private data is collated by the controller 115 from the PSI information previously stored or additionally, from the data entered by the user by means of the remote control unit 125 and the interface 120. The NIT is optional, and a user may choose to omit the NIT for any or all of the programs that are to be stored by means of the menu selection, in which case, step 330 of FIG. 3 is derived.

In addition, private data can be incorporated into the CPSI information tables that are not NIT. For example, private data can be incorporated into the PMT Private User descriptor parts (according to the MPEG 2.6 system standards section). This approach has the advantage of associating private data directly with the elementary streams that constitute the programs, avoiding the need for a separate directory to link elementary streams with private data. In step 335, the controller 115 assembles the PAT and the PMT created for individual programs, in order to form the condensed program specific information (CPSI) for each program. The controller 115 additionally assembles and incorporates into the CPSI the optional CAT and NIT data created for each program. Accordingly, the CPSI comprises a PAT and PMT, and may also include a CAT and an NIT or both. As it was created, the CPSI contains information related to the particular programs selected for storage from the entry of the data stream into the system 25, and excludes program-specific information related to those programs not selected for storage. However, in an alternative way, the CPSI can be created for more than one program selected for storage, from the incoming transport data stream. In which case, the CPSI would include a single PAT and PMT, and may include a single CAT and a single NIT. In this case, these tables contain data that support the identification and retrieval of the plurality of programs selected for storage, as defined in the MPEG standard. In case the programs are selected for storage from two separate transport data streams put into the system 25, for example, the CPSI would contain a single PAT and two PMTs. One PMT for each program that is going to be stored. The CPSI can also include a single CAT and two NITs. One NIT for each program that will be stored. In the recovery of a program from a storage medium, a problem arises if a reproduction device incorrectly applies the CPSI of a different program. The use of incorrect CPSI data, such as the PMT, can result in erroneous identification and assembly of data packets in the recovery of program content, and produce invalid data for visual display or processing, for example . This problem may arise, for example, if a playback device does not apply the CPSI of the recovered program, or does not recognize that the CPSI has changed and continues to apply the previously derived CPSI for a different program. The possibility that this occurs increases if the storage medium contains more than one program. In that In this case, a playback device may cross the boundaries of the program during a trick play or a search operation, for example, and continue to apply the CPSI of the previous program. In order to alleviate the program of applying incorrect CPSI parameters across the boundaries of the program, the controller 115 formats the CPSI in step 340, employing the process of FIG. 4. In step 405 of FIG. 4, in FIG. followed by the start in step 400 the controller 115 determines the type of storage device, and the medium selected by the user, from the input data (SM) provided by means of the interface 120. If the selected means is linear type, that is, a half access in sequence, such as video tape used for digital recording in VHS (DVHS), for example, the controller 115 is directed to perform step 425 following step 410. In step 425 , the controller 115 alters the version number that is associated with the packet format of PAT, PMT, CAT and NIT, according to the MPEG syntax (the MPEG system standards section 2.4.4 - 2.4.4.11). The version number is altered by incrementing the version number continuously between successive repetitions of the CPSI in the program to be stored. The version number counters are continually increased through any overflow conditions. When recovering the program from the storage medium 105, a decoder or a playback device detects changes in the successive version numbers and applies the information of PAT, PMT, CAT and NIT on each presentation in the recovered program. Alternative methods can also be used to alter the version numbers, in order to start a decoder to reacquire the CPSI. The version numbers may be increased between the first two successive presentations of the CPSI, at the beginning of the recording of the program, or between selected CPSI presentations within the program, or between different programs in the storage medium 105, for example. In addition, the version numbers that are presented in the limits of the program, between different programs, do not need to differ for any particular number. However, inside a program, the successive version numbers that are created, must differ by one to comply with MPEG. In applications that do not comply with MPEG, the version numbers of the CPSI table may differ by any value within a program. Another method that may be employed in step 425 is to designate a separate indicator to be used in order to order a reproduction device to apply the CPSI in each CPSI presentation, or on the selected presentations. The assigned indicator would be compatible with the MPEG syntax, and would be located in a data section private, such as within the adaptation field of the PAT or CAT, for example (section 2.4.3.4 of the MPEG system standard). The indicator can be arbitrarily defined, or it can be an existing indicator, such as the 'discontinuity indicator' in the adaptation field of the packet header (defined in section 2.4.3.5 of the MPEG system standard). The discontinuity indicator is set to '1' to indicate to a decoder or playback device that there is a potential discontinuity in the CPSI, and consequently, the following presentation of the information of PAT, PMT, CAT and NIT. This use of the discontinuity indicator is not covered by the MPEG standard. In the context of a data stream not compatible with MPEG, there are also additional methods available, including the designation of an indicator not compatible with MPEG, or the use of a signal to indicate the beginning or the end of the recording of a program, for example. Another technique is to configure a playback device to identify and apply epresentation of the CPSI in a retrieved data stream, regardless of the version number. In which case, step 425 can be derived. If the selected storage medium 105 is of a non-linear type, that is, a means that accommodates access without sequence, such as a disc medium including CDROM or DVD, for example, the controller 115 is directed to perform step 430 following step 415. In a non-linear type media, the CPSI data can be stored either in one or more particular directory locations in the middle, or within the content of the program, as with the medium of linear type. In step 430, in the case where the CPSI is stored in directory locations, the controller 115 alters the version numbers that are associated with the PAT, PMT, CAT and NIT packets in the directory locations. The version numbers are incremented in a manner consistent with the MPEG syntax, to ensure that they are different between different programs on the storage medium 105 (Figure 1). In step 430, in the case where the CPSI is stored within the content of the program, the controller 115 alters the version numbers, as described for step 425, for a linear type medium. In order to ensure that the version numbers of CPSI elements differ between different programs, the controller 115 retrieves the version numbers of the previously recorded programs or files from the storage medium 105 via the interface 95 and the device 90. , before creating the insert the incremented version numbers in the CPSI data. Other methods can also be used to alter the version numbers in step 430. However, the CPSI version numbers must differ between different programs stored in the medium 105. Alternatively, a separate indicator may be designated in step 430, to order a decoder apply the CPSI, either at the beginning of a program, or when crossing the limit of a program. The assigned indicator would be compatible with the MPEG syntax, and would be located in a private data section, such as the adaptation field of the PAT or CAT, for example (section 2.4.3.4 of the MPEG system standard). The indicator can be arbitrarily defined, or it can be an existing indicator, such as the 'discontinuity indicator' in the packet header adaptation field, as described in relation to step 425. In the context of a data stream not compatible with MPEG, you can designate an indicator to order a decoder or a playback device, which applies the CPSI. This indicator can denote the start or end of the recording of a program, for example. If the selected storage medium 105 is solid state, i.e., a semiconductor memory, such as a ram, the controller 115 is included to perform step 430 following step 420. In a medium of solid state type, such as With a non-linear means, the CPSI data is normally stored in one or more locations particular from the directory in the middle, and are easily accessible from other storage locations. Accordingly, the controller 115 alleviates the problem of applying incorrect CPSI parameters across the program boundaries by formatting the CPSI for a solid state medium, as it does for a non-linear medium. That is, the controller 115 uses the process of step 430. The process of Figure 4 ends step 435 following steps 425 or 430, in turn completing the formatting of the CPSI of step 340 of Figure 3. The The process of Figure 3 ends in step 345, followed by step 340, which completes the formation of the CPSI for the programs selected for storage, of the spanning passage 225 of Figure 2. The controller 115 continues the process of the Figure 2 with the execution of step 230. In step 230, the controller 115 forms the CPSI data in sessions, according to the MPEG syntax (paragraphs 2.4.4.3 - 2.4.4.11 of the MPEG system standard). The sections are formed for the PAT data and the PMT data. Sections are also formed for the optional CAT and NIT (private data), if these tables are incorporated in the CPSI in the process described above in Figure 3. The resulting packet data includes table identifiers, section length identifiers, and the version numbers previously determined in the process. Figure 4 It should be noted that the PAT section also includes a transport stream identifier, which associates the PAT with a particular transport stream. The controller 115 obtains this identifier from the data of the original PSI, and inserts it into the transport stream identifier field of the PAT section of the CPSI. However, this field can be left optionally unaltered or blank. In step 230, the controller adds the header data to the CPSI data sections, to format and pack the CPSI data to be inserted into the data stream to be stored. The controller 115 creates the headers according to sections 2.4.3.2 and 2.4.3.3 of the MPEG system standard, from the PSI header data stored in the internal memory of the controller 115. However, the data of the CPSIs are of a different length than the corresponding PSI section data. Accordingly, the controller 115 creates new header parameters, including the 'continuity count' indicator and the 'payload unit start indicator', and are inserted into the respective indicator fields within the header data. The new continuity account indicator created by the controller 115 reflects, for example, the number of packets per PID for the CPSI elements, instead of the different number of packages by PID of the corresponding PSI elements. The new payload unit start indicator created by the controller 115 identifies, for example, the first byte of the CPSI section, instead of the first byte of the corresponding PSI section. Continuing with Figure 2, in step 235, the CPSI in the form of the MPEG-compatible section data in packets formed in step 230, is provided by the controller 115 to the multiplexer 110 (Figure 1). Data streams are also provided in packets of program content from unit 47 or unit 50, as discussed above in connection with step 215, to multiplexer 110. In step 235, controller 115 multiplexes between the content of the program. program and the input of the CPSI data streams to the multiplexer 110, using the line selection signal C to create a composite data stream, which is produced by the multiplexer 110 to the storage interface 95. The composite data stream includes program content packages and CPSI packages. The controller 115 synchronizes the insertion of the CPSI packets into the data stream of the program to be stored, in response to a PSI interrupt signal from the control unit 65 (Figure 1). The interruption of PSI indicates the presence of PSI packets in buffer zone 60, as discussed in connection with step 205. In this way, the PAT, PMT, CAT, and NIT sections in CPSI packages are inserted in the PSI locations to replace the corresponding sections of the PSI. The crypto-encoded CPSI data can be inserted into the cryptically encoded or non-encoded program content data streams that cryptically enter the multiplexer 110, in order to create cryptically encoded or crypto-encoded programs for storage. The controller 115, in step 235, replaces each PSI data presentation in the data stream to be stored, with the corresponding CPSI data, regardless of the type of media the user has selected for storage. However, a further reduction in the coding surplus can be achieved by inserting the CPSI at the selected PSI locations, or by inserting the CPSI only once within the program to be stored. The repetition frequency of the CPSI within the program to be stored can be determined by the controller 115, based on factors including, for example, minimum PSI element repetition frequency limitations, user preference, limitations of data storage capacity, or the type of storage medium selected. The proposed system for high definition television (HDTV) by the ATSC, specifies a minimum repetition frequency for certain PSI elements, including a minimum interval of 10 milliseconds between PAT repeats, for example (Digital Television Standard for High Definition Television Broadcasting, Annex C, section 5.4, of 12 April 1995). In addition, in the storage medium of non-linear or solid-state type, for example, reducing the number of repetitions of the CPSI, or inserting the CPSI only once in a program that is to be stored, does not adversely affect the latency of program recovery. This is because these types of media allow quick access to data not in sequence (random). In step 240, the storage interface 95 receives the programs to be stored in the form of the packet data stream that it incorporates into the CPSI (hereinafter referred to as the CPSI stream) from the multiplexer 110. The process of Figure 2 used by the controller 115 to generate the CPSI stream ends at step 245. It should be noted that the CPSI stream can alternatively be provided to other applications in step 240, such as visual display or communication via interface 70, instead of its storage by means of interface 95. CPSI current from multiplexer 110, is placed in buffer zone through the interface 95, for reduce the gaps and the variation of the bit rate in the data. The data set in the resulting buffer zone is processed by the storage device 90, which will be suitable for storage in the medium 105. The controller 115 initiates and controls the operation of the storage device 90 (Figure 1) by means of the command via of the input / output port 100, using a standardized CEBus control protocol (Home Automation Standard (CEBus), EIA / IS-60, December 1989). The storage device 90 is a DVHS-type device of linear storage medium that encodes the data stream placed in the buffer zone from the interface 95, using known error coding techniques, such as channel coding, interleaving, and Reed Solomon coding, to produce a coded stream of data suitable for storage. The unit 90 stores the resulting encoded data stream that incorporates the CPSI in a tape medium 105. Other tape storage systems allow the two data streams to be recorded in parallel. The first data stream, which normally contains most of the content of the program, is conventionally stored in a helical fashion on the tape. A second data stream, usually with a much lower data density and bit rate, is stored in parallel, in a linear fashion (not helical), in an auxiliary track located towards the edge of the tape. In this type of storage system, the device 90 separates the CPSI data from the CPSI stream, and conveniently stores the CPSI data in the auxiliary track. The unit 90 stores the CPSI data in such a way that each program recorded on the tape carries its associated CPSI data on the auxiliary track, in parallel with the content of the program. The repetition frequency of the CPSI data in the auxiliary track can be adjusted, subject to the data speed limitations of the auxiliary track. Alternatively, the CPSI can be stored in helical helical tracks, or in data management areas, including track information areas (TIAs), and in track and insert information sectors (ITI sectors). The areas of data management are stored in helical or non-helical tracks, making a parallel with the content of the program. Although described as a DVHS device that stores data in a linear type storage medium in the exemplary embodiment of Figure 1, the storage unit 90 can be any type of storage unit. For example, the unit 90 may be a solid state or non-linear type device for storing data in ram, or on a DVD OR CDROM. If the unit 90 and the medium 105 are storage systems of non-linear type or of solid state, unit 90 separates the CPSI data from the CPSI stream, and stores the CPSI data in a designated section of the middle directory. This conveniently avoids repeated storage of the CPSI, and reduces the storage capacity required. Alternatively, unit 90 can store the CPSI stream as it was formed, and put it into unit 90, incorporating one or more repetitions of the CPSI data. In addition, the system 25 of Figure 1 may incorporate fJP 10 a plurality of storage / retrieval lines that support the operation of a plurality of storage devices of different types, including the linear, non-linear, and solid-state types. The single storage / retrieval line shown in Figure 1, comprises the units 47, 90, 95, 105, and 110, as already described. By replicating these elements to create parallel storage functions, the system 25 already extends to incorporate a plurality of storage lines. The storage line and the programs intended for a device of particular storage are selected by the user generated data (SP, SM) inserted into the controller 115 via the interface 120 following the on-screen menu selection with the remote control unit 125, as described above. 25 System 25 of Figure 1 retrieves the programs from the storage device 90 and the medium 105 in a reproduction mode, using the process of Figure 5. The recovered data streams are processed by the system 25, and are provided to the application devices 75, 80, and 85 for visual display or output, for example. Alternatively, the program data streams can be stored in other parallel storage devices (not shown in Figure 1 to simplify the drawing). In step 505 of Figure 5, following the start in step 500, the data generated by the user (SR, SM) is put into the controller 115 of the system 25 (Figure 1), identifying the programs to be recovered , and the storage device from which the programs will be recovered. The user selection data is input to the controller 115 via the interface 120, following the selection of the on-screen menu with the remote control unit 125. It is assumed, for example purposes, that the user selects the programs that are going away. to recover from the storage device 90 (Figure 1). The controller 115 in step 510 initiates the recovery of the data streams of the program selected by the device 90 from the means 105, by means of the command via the input / output port 100, using the standardized CEBus control protocol as described in FIG. discussed earlier.

The device 90 decodes the error-coded data retrieved from the medium 105, to retrieve the corresponding data originally provided to the device 90 for storage. The device 90 can be a DVHS linear type storage unit, or another type of storage unit, such as a solid state RAM, or a non-linear type DVD or CDROM type device. The recovered decoded data streams are transferred, in step 510, via device 90, to interface 95. This data transfer is controlled and synchronized by controller 115 by means of the standard CEBus. The interface 95 places the data received from the unit 90 in the buffer zone to adjust the time intervals between the data packets, in order to provide a buffer zone data output that is compatible with MPEG, and that complies with the MPEG bit rate limitations. In step 515, the controller 115 directs the output set in buffer area from the interface 95 (the playback data stream) via the multiplexer 37 to the PID selection units 45 and 47, using the selection signal of line C. In step 520, units 45 and 47, and the remaining units of system 25, process the playback data stream, either for storage by multiplexer 110, or for its use application via the interface 70. Both the reproduction data stream from the unit 95, and the data stream transmitted from the selector 35, following the selection by means of the multiplexer 37, are processed by the system 25 of a Similarly. Both data streams are processed in the manner described above for the transmitted data stream. However, the reproduction data stream selected by multiplexer 37 already incorporates the CPSI. Accordingly, the reproduction mode, the controller 115 in step 520, does not perform the steps related to the formation of the CPSI described in connection with Figures 2 to 4. In the example reproduction mode shown in Figure 5, the system 25, in step 520, decodes the playback data stream to convey decoded data to the application decoders 80 and 85 for visual display. In this mode, the system 25 applies the CPSI data contained in the playback data stream, in accordance with the MPEG standard, to provide a decoded data stream per transport representing the SR of the selected program. In step 520, the controller 115 has access to the CPSI data of the playback data stream by means of the buffer zone 60, and examines the data for a change in the version number that occurs between successive CPSI elements. The controller 115 also examines the reproduction data stream to determine a discontinuity, as indicated by a 'discontinuity indicator' in the packet header adaptation field (defined in section 2.4.3.5 of the MPEG system standard). Upon detecting a change in the version number or discontinuity, the controller 115 applies the latest complete CPSI data to decode the reproduction data stream by transport. It should be noted that the controller 115 can also be programmed to apply the latest complete CPSI data on a variety of other conditions, including the detection of a bad continuity account match between the successive packets of a particular PID, and error indications. Of transport. Both parameters are present in the packet headers of the playback data stream (defined in section 2.4.3.2 of the MPEG system standard). The controller 115 can also be programmed to apply the CPSI by detecting a discontinuity between the presentation time stamps (PTSs), or the decoding time stamps (DTSs) that are defined in the MPEG standard, or other defined time stamps. by the user. However, note that the syntax compatible with MPEG requires that the discontinuity indicator be set to indicate the presentation of a bad match of the continuity account.

The CPSI is applied in the decoding by transporting the reproduction data stream using the PID filters 45 and 47, the cryptic decoder 50, the decoder 55, the buffer zone 60, and the control unit 65, of a manner similar to that described above in relation to Figure 1. The data stream decoded by transport, excluding the CPSI, is provided, via interface 70, to the application decoders 80 and 85, for the decoding fe 10. MPEG and image reproduction. In other modes the system 25 provides the reproduction data stream that incorporates the CPSI, to other application devices, such as the high-speed data port 75, for example. Then the CPSI is available to be applied in the decoding by transporting the reproduction data stream, as necessary, by these application devices or subsequent devices. If 1 playback data stream is to be stored in a second storage device other than the device 90, for example, the The multiplexer 110 provides the data stream, incorporating the CPSI, to the second storage device, by means of a second storage interface. In addition, the second storage device and the interface (none are shown in Figure 1), mimic the operation and function of units 90 and 95, respectively.

In the default periods, before applying the CPSI, the system 25 provides decoded data to the video decoder 85, which represents a previously determined video image for visual display, such as a 'blue screen', or a 'frozen frame' ', for example. In a similar manner, in the default periods, before detecting the change in the version number, and of applying the CPSI, the system 25 provides data to the audio decoder 80, to blank the audio output. These measures prevent an annoying video or audio output to the playback devices, until the correct CPSI data has been applied, to provide a valid material for viewing or listening. The default periods include, for example, the intervals from any of the following conditions: a) detection of a program end indicator, or system energization; b) the detection of a user command that involves fast playback or skipping the content (trick-play); or c) the detection of an error condition that indicates that valid video packets have not been detected, until the detection of a change in the version number of the CPSI element. The data from the interface 70, decoded in MPEG through application decoders 80 and 85, are presented by means of audio and image reproduction devices in units 80 and 85, respectively. This terminates the reproduction process, which ends in step 530. It should be noted that the controller 115 may alternatively employ any of the other previously discussed methods, to prevent the application of incorrect CPSI data. The architecture of Figure 1 is not exclusive. Other architectures can be derived according to the principles of the invention, to realize the same objectives. In addition, the functions of the elements of the architecture of Figure 1, and the process steps of Figures 2 to 5, can be implemented totally or partially within the programmed instructions of a microprocessor. In addition, the principles of the invention apply to any form of electronic program guide not compatible with MPEG, and are not restricted to those transmitted in PSI tables compatible with MPEG.

Claims (14)

1. A storage medium that has registered in it, a program of data in packets, in a data format that includes: the specific information of the current program suitable for use in the recovery of the data content of the program, which comprises: (a ) the program map information that associates the packet identifiers (PIDs) with the data streams in individual packets that make up the program; (b) the association information of the program that associates the program with the PIDs, which identify the packages that comprise the map information of the program; and (c) a command parameter, characterized by: the command parameter being for ordering a decoder not to consider the information specific to the previous program, and for ordering the decoder to apply the specific information of the current program when decoding this program.

2. A storage medium according to claim 1, wherein: the command parameter instructs a decoder to apply the specific information of the current program when recovering this program from a storage medium.

3. A storage medium according to claim 1, wherein: the command parameter is incorporated into the data definable by the user in a data stream compatible with MPEG.

4. A storage medium according to claim 1, wherein: the program-specific information is stored in a separate location of this program.

5. A storage medium according to claim 4, wherein: the separate location is adjacent to the program.

6. A storage medium according to claim 4, wherein: the storage medium is a medium of linear type that includes tape means; and the program-specific information is stored in an auxiliary recording track adjacent to the recording tracks that store the program.

7. A storage medium according to claim 1, wherein: the program map information includes Private data elements that describe the program, selected from title, duration, program description, violence evaluation, property evaluation for age, recording time, recording date, version list.

8. A storage medium according to claim 1, wherein: the specific information of the program also includes the information of the network, and this network information incorporates private data elements selected from title, duration, description of the program, violence evaluation, property evaluation for age, recording time, recording date, version list.

9. A method for forming program-specific information suitable for use in retrieving the data content of a program, in the form of a packet data stream, which comprises the steps of: creating the program map information that associates the packet identifiers (PIDs) with the data streams in individual packets that make up the program; create the association information of the program that associates the program with the PIDs that identify the packages that comprise the map information of the program; and characterized by: incorporating a command parameter inside the specific information of the current program, this command parameter being suitable for ordering a decoder • not to consider the specific information of the previous program, and to order the decoder to apply the specific information of the current program when processing this program. A method according to claim 4, wherein: the command parameter is suitable for ordering a decoder 10 to apply the specific information of the current program when recovering the program from a storage medium. 11. A method according to claim 9, where: 15 this parameter is transmitted in user definable data inside a data stream compatible with MPEG. 12. A method according to claim 9, which further includes the step of: creating private data elements that describe the program, selected from title, duration, program description, violence evaluation, property evaluation for age, recording time, recording date, version list. 13. A method according to claim 12, which also includes the step of: incorporating the private data elements into a user-defined section of the program map information. 14. A method according to claim 12, which further includes the steps of: creating the network information; and incorporate the private data elements into the network information. SUMMARY A storage medium format for a storage medium (105) containing packet data programs, includes packet identifiers (PIDs) that identify the data streams in individual packets that constitute a program. The data format facilitates the association and assembly of data streams in program packets, by means of a decoder, independent of the PID demapping data. The PIDs include a base PID to identify a data stream, and a second PID of a predefined value previously determined with the base PID, to identify a second data stream. The data streams in corresponding packets that constitute different programs receive the same PID (115). The storage media format can also include program-specific information (PSI) suitable for use in retrieving the data content of a program. The PSI includes an MPEG-type program map table (PMT), and an MPEG-type program association table (PAT), and incorporates a suitable parameter for ordering a decoder (25) to apply the PSI in the decoding of the program, regardless of the content of the previous PSI. In addition, the PSI can incorporate a version number that varies between successive PSI submissions, regardless of the substantive change in the content of the PSI. You can also include one or more private data elements in the PMT, to describe the program. • k -k -k -k -k