A SYSTEM FOR PROCESSING PROGRAMS E
TIMING INFORMATION OF DERIVATIVE SYSTEM
MULTIPLE TRANSMISSION SOURCES This invention relates to the processing of programs and system timing information and associated content classification received from multiple transmission sources for reproduction, recording and production. In digital audio and video transmission applications, packet program information transmitted to a video decoder, such as a High Definition Television (HDTV) receiver, contains transmission channels, eg, Fox 5®, Channel 13 ®, of multiple transmitters. The packet program information of an individual transmitter may contain the data content of several program sub-channels that occupy the frequency spectrum previously occupied by a single analog transmission channel. The sub-channels may include, for example, digital services including a main program channel, a financial services channel offering stock quotes, a sports news services channel and an interactive and shopping channel, all passed in the width of 6 MHz band previously assigned to a single analog transmission channel compatible with NTSC. The packet information of an individual transmitter also contains additional information as well as the data content of the sub-channels of the program. The additional information includes system information and program-specific data used in identification and assembly packages comprising selected programs and also includes text information and program guidance associated with the transmitted program data. In particular, the additional system information includes system timing information that provides a time clock reference enabling the enabling of the determination of a time at which a specific program is to be transmitted. The additional specific data of the program may include classification information of the program content (such as PG-13 etc.) allowing control of the parents of the transmission using a conditional access system such as for example a V-chip type system. The additional content classification and timing information of the system is commonly coded along with program data to meet the requirements of a known standard. One such standard that details an information protocol that incorporates content classification information and system timing for transmission applications is called, System Information Protocol and Program for Land and Cable Transmission, published by the Committee of Advanced Television Systems (ATSC), on November 10, 1997, hereinafter referred to as the PSIP standard. A number of problems can arise in a digital video system in the specific information of the program and timing of the processing system of multiple transmission sources. Specifically, problems arise in the use of system timing information to program program processing functions and to display a current time to a user. Problems also arise in providing a conditional access system that uses accurate information from the content classification of the program to authorize access to programs while providing desirable features such as a user's ability to optionally override a previously established content classification limit. Thus, there is a need to solve these problems as well as the problems arising. A system for initiating programmed program processing functions such as program display, recording or playback, derives a time clock based on a current time reference indication produced by a particular transmission source. The derived time clock is used to initiate programmed processing functions for programs derived from the particular transmission source and the time clocks derived from sources that are not the particular transmission source are not considered. The system can display a second time clock different from the derived time clock. Brief Description of the Drawings In the drawings: Figure 1, is a block diagram of a digital video reception apparatus for program content classification information and timing of the processing system of multiple transmission sources, in accordance with the principles of the invention. Figure 2 shows a flowchart for a method for programming and executing program processing functions and displaying a time clock according to the invention. Figure 3 shows a program guide user interface for initiating the programming of program processing functions, in accordance with the invention. Figure 4 shows a flow chart for a method for conditioning access to programs based on program content ratings received from multiple transmission sources, in accordance with the invention. Figure 5 shows a method for generating program-specific information incorporating program content classification information and system timing according to the invention. Figure 1 is a block diagram of a digital video reception system for demodulating and decoding transmission signals from multiple transmission sources, in accordance with the principles of the invention. Although the disclosed system is described in the context of a system for receiving terrestrial transmission video signals by incorporating additional timing information and program specific information in M PEG compatible format, it is exemplary only. The M PEG data format is widely adopted and is detailed in the M PEG2 (Cinematographic Film Experts) coding standard, hereafter referred to as the "MPEG standard", (I SO / I EC 13818-1, 10 June 1994, and ISO / I EC 1 3818-2, January 20, 1995). Timing and program-specific information can be of a variety of types. For example, it may meet the Program Specific Information (PSI) requirements specified in section 2.4.4 of the M PEG system standard, or it may comply with the System Information Protocol and Program for Land and Cable Transmission mentioned above or others. ATSC standards. Alternatively, it can be formed in accordance with the requirements of the owner or according to the needs of the client of a particular system. The principles of the invention can be applied to computer, internet, satellite, cable or terrestrial network transmission systems in which the type of coding or modulation format can be varied. Such systems may include, for example, systems not compatible with M PEG, involving other types of coded data streams and other methods of transferring program-specific information. Additionally, although the disclosed system is described as processing transmission programs, it is exemplary only. The term "program" is used to represent, for example, any form of data in packets such as audio data, telephone messages, computer programs, Internet data or other communications. In the video receiver system of Figure 1, a transmitter carrier modulated with signals carrying audio, video and associated data representing broadcast program content is received by antenna 10 and processed by unit 13. The signal of The resulting digital output is demodulated by the demodulator 15. The demodulated output of the unit 15 is decoded into a grid, formed into a map in data segments of byte length, deinterleaved and corrected for Reed-Solomon error by the decoder 17. corrected output data from unit 17 is in the form of a transport data stream compatible with MPEG containing data, video and audio components demultiplexed by unit 22, which are further processed by the other elements of decoder system 100 In a way, decoder 100 provides decoded M-PEG data for audio display and playback in units 50 and 55, respectively. In another mode, the transport stream of the unit 17 is processed by the decoder 100 to provide a data stream compatible with MPEG for storage in a storage medium 105 via the storage device 90. A user selects to see either a channel television (channel selected by the user-SC) or an on-screen menu, such as a program guide, using a remote control unit 70. The controller 60 uses the selection information provided from the remote control unit 70 via the interface 65 to properly configure the elements of Figure 1 to receive a desired program channel to view it. The controller 60 comprises the processor 62 and the processor 64. The unit 62 processes (i.e., analyzes, compares and coalesces) the system timing information and the program-specific information including classification of the program content, and guidance information of the program. Program. The processor 64 performs the remaining control functions required in the operation of the decoder 100. Although the functions of the unit 60 can be implemented as separate elements 62 and 64 as shown in Figure 1, they can be implemented alternately in a single processor. For example, the functions of units 62 and 64 can be incorporated into the programmed instructions of a microprocessor. The controller 60 configures the processor 13, the demodulator 15, the decoder 17 and the decoder system 100 to demodulate and decode the format of the input signal and the type of coding. Additionally, the controller 60 configures the units 13, 15 and 17 for other communication modes, such as for receiving cable television (CATV) signals and for bidirectional communication via the coaxial line 14 or for bidirectional communication (for example, Internet), for example, via telephone line 1 1. In an analog video mode, an NTSC compatible signal is received by the units 13, 15 and 17 and processed by the decoder 100 for video display and audio playback in the units 50 and 55, respectively. The units 13, 15 and 17 and the sub-units in the decoder 100 are individually configured for the type of input signal by the controller 60 which establishes control register values in these elements using a bidirectional data and control signal bus. C. The transport stream provided to the decoder 100 comprises data packets containing program data and additional system timing information and program-specific information including classification of program content, and program guidance information. The unit 22 directs the additional information packets to the controller 60, which analyzes, compares and aggregates this information in tables arranged in hierarchical order. The individual data packets comprising the program channel selected by the SC User are identified and matched using the specific information of the combined program. The system timing information contains a time reference indicator and associated correction data (for example, a summer time indicator and displacement information by adjusting the time change, leap years, etc.). This timing information is sufficient for a decoder to convert the time reference indicator to a time clock (e.g., the date and time of the east coast of the United States of America) to establish a date and time of day of the day. the future transmission of a program by the transmitter of the program. This time clock can be used to initiate programmed program processing functions including program transmission, program recording and program playback, for example. Additionally, the program-specific information contains conditional access, network information, and relationship and identification data that enable the system of Figure 1 to tune to a desired channel and assemble data packets to form complete programs. The specific information of the program also contains classification information of the content of the additional program (for example, an Electronic Program Guide - EPG) and descriptive text related to the transmission programs as well as data that support the identification and set of this additional information. The system-specific and program-specific timing information is combined by the controller 60 into multiple hierarchically and interrelated tables. An exemplary hierarchical table configuration compatible with PSI P includes a System Time Table (STT), a Master Guide Table (MGT), a Channel I nformation Table (CIT), Event I nformation Tables (EITs ) and optional tables such as Extended Text Tables (ETTs) and a Classification Region Table (RRT). The System Time Table contains a time reference indicator and associated correction data sufficient for a decoder to set a transmission time of a program for an accurate transmission source within about 4 seconds, for example. The Master Guide Table contains information for acquiring program-specific information transferred in other tables such as identifiers to identify data packets associated with the other tables. The Channel Information Table contains information for tuning and navigation to receive a program channel selected by the User. The Event Information Table contains descriptive lists of programs (events) that can be received on the channels listed in the Channel Information Table. The Extended Text Table contains text messages that describe programs and program channels. The Classification Region Table contains information on the classification of program content such as classification information compatible with V-chip or MPAA (Association of Motion Picture Films of America) that is compared by region (ie, by country or by state). the United States of North America). The additional program-specific information that describes and complements items within the hierarchical tables is transferred into the information elements of the descriptor. Information that associates a content classification of the program with a particular program of a particular transmission source can be transferred into a descriptor that informs the content that is included in an Event Information Table or a PMT. In other modalities, the information of classification of the content of the program and the timing of the system that associates a specific program with a specific classification can be contained in other tables, data formats, or descriptors such as the descriptor of the subtitling service or the information it can be transferred into user definable data. The additional classifications of program content are transferred in vertical signal blanking intervals compatible with NTSC processed by the analog processor 27 within the decoder 100 in the analog video mode. The system-specific and program-timing information acquired by the controller 60 via the unit 22 is stored in the internal memory of the unit 60. The controller 60 uses the timing information of the system and of the classification of the content acquired in conditioning the access to programs and programs program processing functions including transmission, recording and playback of the program. The controller 60 employs the process of Figure 2 to execute programmed program processing functions including transmission, recording and playback of the program. In other embodiments, a process corresponding to the process of Figure 2 (and Figure 4) can be used to execute other programmed functions including program transmission, conversion of program standards, program encryption, decryption, mixing, decoding and its functions derivatives including the termination of any of these processing functions. When executing the programmed processing of a particular program, the controller 60 adaptively generates a time-of-programming clock of a time reference indication (e.g., in the System Time Table) provided by the program's transmission source. particular. This generated programming clock is used to take the start time or for processing functions of the programmed program. The previously derived time clocks (for example, from other transmission sources) are not considered when starting the scheduled processing of this particular program. The programming time clock is resynchronized to the time reference information of the System Time Table provided by a particular transmission source before starting the scheduled processing of any program produced by that particular source. These characteristics address the problem of avoiding the application of incorrect program-specific information parameters (parameters within the Master Guide Table, Channel Information Table, Event I nformation Table, Extended Text Table, and Region Table of Classification, etc.) across program boundaries. This can occur if the processing of the program is programmed using an unspecified time clock such as a clock derived from a transmission source other than the source of the specific program to be processed. An inaccuracy of the time clock of 10 seconds or more is very possible under these conditions due to program transmission delays and other delays that occur in a system using multiple transmission sources. As a result of this inaccuracy of the time clock, the wrong program can be recorded (or viewed or played) in overlapping periods between the start or end of the program recording and the actual program transmission time. Additionally, a program can be erroneously recorded using the program-specific information parameters of a program previously processed during program segments that occur in the overlap periods. Consequently, in program playback, incorrect program parameters are applied during the overlap segments. This may result, for example, in incorrect decoding including incorrect identification and acquisition of the package or use of incorrect program content classifications. As a result, invalid and momentarily objectionable images can be displayed to a user. Under these conditions, a portion of a program whose content is classified as adults only may be displayed incorrectly before a child, for example. The controller 60 employs the process of Figure 2 to program and execute program processing functions by starting a user of a programming function. After the start in step 200, the controller 60 in step 203 schedules the observation of a program (including tuning and acquisition) recording or playback in response to a user programming command via the program guide interface of Figure 3 deployed in deployment 50 (Figure 1). Other modes may employ alternative user interfaces for this programming function. When viewing or recording the programming program via the guide of the program in Figure 3, a user navigates to the desired channel and program using menu icons 853 and 855. The user selects a program, for example, a news program 849 highlighting the news icon 849 and program the news program 849 for deployment or recording by selecting the 805 icon or the 810 icon, respectively. A user can similarly schedule the reproduction of a movie such as the movie article 847 (Terminator I I) of the storage device 90 and the medium 105 (Figure 1). The user programs the playback of the movie by highlighting the movie article 847 and selecting the icon 815. In other embodiments, a user may program the display, recording or playback of a program by other methods such as using the buttons of the remote unit. instead of the icons of the program guide 805, 810 and 815. When the user selects the icons 805 or 810, the controller 60 stores the scheduled times of transmission and termination of the news article 849 in the internal memory. The controller 60 determines the scheduled times of transmission and termination of the news item 849 of the stored program guide information derived previously from the Event Information Table. When the user selects the icon 815, the controller 60 in conjunction with the unit 37 (Figure 1) generates a programming menu allowing the user to insert a time for future playback of the 847 movie or to select the immediate reproduction of the movie. A user selects the control and navigation icons and inserts the hours, etc. using the remote control 70 which supports the manipulation of the cursor (or a configuration based on an alternative cursor such as a mouse or a keyboard system). Returning to the process of Figure 2, the controller 60 in step 205 configures the units 13, 15 and 17 (Figure 1) and the elements of the decoder 100 to receive program information in packets containing a program selected by the user. The controller 60 configures the processor 13, the demodulator 15 and the decoder 17 to receive the data format and the channel frequency specific to the transmission channel of the desired program transmitter (previously selected in step 203). In step 210, the controller 60 acquires packets comprising System Time Table data from the transmission source of the desired program by configuring the demultiplexer 22 with the PI Ds of the predetermined System Time Table and the identification data of the table (Table_I D). Thus, the controller 60 acquires the data from the System Time Table containing a reference indication of current time and time correction data produced by the transmission source of the desired program. Data from the System Time Table is transmitted and acquired at predetermined periodic intervals (which the PSIP standard recommends are at least one per second). In step 215, in the program display and recording modes, the controller 60 derives a time clock using the time reference indication of the System Time Table (a value that indicates the number of seconds elapsed from one hour base, specifically from 12 a.m. on January 6, 1980) together with correction data of the System Time Table including a displacement value and a time-of-day time indicator (in accordance with section 6.1 of the PSIP standard) . The derived time clock consists of a date and time and includes the year, month, day and time of day. When deriving the time clock from the time reference indication, the following four values are calculated: 1) Number of minutes of the Base = (seconds received from the Base) / 60 2) Number of hours of the Base = (minutes received from the
Base) / 60 3) Number of days of the Base = (hours of the Base) / 24 4) Number of years of the Base = (days of the Base) / (days per year), where, days per year = 365, or 366 in a leap year Note, The Base in the previous expressions is 12 am of January 6, 1980. Of the four values mentioned above, the components of the derived time clock, year, month, day and time of day are determined as indicated below. 1) current year = Base year + number of Base years, 2) current day of the year = number of Base days - (number of Base years * days per year), Also, the current month and day of the Base month are determined directly from the current year and from the current year's day. 3) current time of the day = number of hours of the Base - (number of days of the Base * 24), 4) current minute of the hour = number of minutes received from the Base - (number of hours of the Base * 60 ) 5) current second in minute = number of seconds received from Base - (number of minutes in Base * 60) Then, the derived time clock is the current total time = year, month, day, hour, minute and second current. In addition, the derived time clock is corrected using the correction data of the System Time Table including a shift value and the daylight saving time indicator in accordance with section 6.1 of the PSIP standard and Annex A (or by factors of corresponding correction in systems not compatible with PSIP). In step 215 in the program play mode, the controller 60 uses an internal system clock synchronized with the operation of the storage device 90 for the start of movie playback. In other embodiments, the controller 60 may derive a programming clock from a variety of other forms of time clock data. It is desirable that the time clock data used to derive the programming clock be synchronized with the time clock transmitted by the transmission source when transmitting the desired program. This is achieved, for example, by using data from the System Time Table of the transmission source of the desired program in the display and recording modes and by using a synchronized system clock with a playback device in playback mode. The data of the System Time Table and the time clocks derived from the data of the System Time Table of transmission sources that are not the source of the desired program are not considered in the initiation of the programmed processing of the desired program. In step 220, the controller 60 updates (i.e., corrects and resynchronizes) a stored time clock stored internally with the time clock information derived in step 215. The programming clock is periodically updated from this way of derived time clock values obtained from the updated System Time Table data received at intervals of one second or less. In the time intervals between updating the programming clock of the data of the System Time Table, the programming clock is maintained using a clock frequency derived from internal crystal in the controller 60. The controller 60 in other modes may create and maintain separate programming clocks and / or correction information and time reference derived from the System Time Table associated with each program transmission source (e.g., a clock for each transmission source) using the method of steps 205-215. In step 220, if there is no available time clock reference information of the desired program transmission source, the controller 60 uses a previously derived programming clock. The controller 60 in step 225 initializes the processing of the desired program at the scheduled processing time previously established in step 203. The controller 60 determines whether the hours of starting the processing (previously programmed in step 203) have arrived based on the programmed clock determined in step 220. The controller 60 in step 225 initiates processing of the desired program for deployment, recording or reproduction at the time of scheduled processing, identifying and acquiring the packages that comprise the desired program. Specifically, the controller 60 and the processor 22 (Figure 1) determine from the Channel Information Table the PIDs of video, audio and sub-picture streams in the packet decoded transport stream input to the decoder 100 of the unit 17. The video, audio and sub-video streams constitute the desired program transmitted on the selected channel SC. The processor 22 provides compatible video, audio and sub-video streams to the video decoder 25, the audio decoder 35 and the sub-image processor 30, respectively. The streams of audio and video contain compressed audio and video data representing the program content of the selected channel SC. The sub-image data contains the information from the Event Information Table, the Extended Text Table and the Classification Region Table associated with the content of the SC channel program. The decoder 25 decodes and decompresses the video data into MPEG-compatible packets of the unit 22 and provides programmatic uncompressed pixel data to the NTSC 45 encoder via the multiplexer 40. Similarly, the audio processor 35 decodes the audio data into packages of the unit 22 and provides amplified and decoded audio data, synchronized with the associated decompressed video data, to the device 55 for audio reproduction. The processor 30 decodes and decompresses sub-image data received from the unit 22. The joint processor 30 compares and interprets the data from the Event Information Table, the Classification Region Table and the Extended Text Table of the unit. 22 to produce formatted program guide data for display on-screen display 37. Screen display 37 processes the Event Information Table, Classification Region Table, and Extended Text Table and other information to generate data in the form of pixel maps representing information, control and subtitling menu displays that include selectable menu options and other items for display on the display device 50. The control and information menus that are displayed allow the user to select a program to view and display. schedule future program processing functions including a) tune in to receive a selected program I watched it, b) recorded a program on the storage medium 105, and c) played a program on the medium 105. The control and information displays, included text and graphics produced by the on-screen display generator 37, were generated in the form of pixel map data superimposed under the direction of the controller 60. The pixel map data superimposed under the address of the unit 37 are combined and synchronized with the decompressed pixel representative data of the M PEG decoder 25 in the encoder 45 via the multiplexer 40 under the direction of the controller 60. The combined pixel map data representing a video program in the SC channel together with associated sub-picture data is encoded by the NTSC 45 encoder and output to the device 50. for deployment. In step 230 (Figure 2) the controller 60 generates a second time clock for display to a user so that the item of the displayed time clock 857 (which also comprises a date) shown in the program guide of Figure 3 , for example. The second time clock is different from the programming clock and is generated to prevent the time change discontinuities occurring in the programming clock from being displayed and disturbing a user. The controller 60 generates the second time clock a) by filtering the programming time clock values, or b) updating the second time clock in periods when it is not visible to a user. Alternatively, a second time clock which is independent of the programming clock may be used already) is based on an internal clock of the controller 60 and the decoder system 100, b) is received on a channel that is separate and distinct from the channels of the content of the program, or c) is received inserted in a composite program guide that lists programs from multiple sources of transmission, for example. The process of Figure 2 ends at step 235. The controller 60 employs the method of Figure 4 to process program information into packets from different different programming sources using functionally equivalent program-specific information parameters including content classification data. of program dynamically selected from alternative transmission sources. When processing packet program information, the controller 60 adaptively selects a specific program parameter based on the transmit source of the parameter. The process of Figure 4 is also applicable to the programming of NTSC analog video compatible programs and to the acquisition and processing of classification information derived from vertical blanking intervals. In the exemplary embodiment of Figure 4, the controller 60 conditions access to programs based on program content ratings received from multiple transmission sources that provide digital or analog data. The controller 60 conditions the access to programs in response to user commands inserted via information and control menus generated by the display unit 37 and displayed in the unit 50 (as described in relation to Figure 2). The information and control menus allow a user to insert content classification profiles for himself and others, by providing titration data comprising a user identification (I D) and for example, a predetermined password. A content classification profile allows a user to set a minimum level of user classification for individual users of the decoder 100 in accordance with a classification system selected by the user. A user may select levels of classification limit in accordance with one of a number of different classification systems such as the V-chip, MPAA or other systems. Thus, the decoder 100 enables parental control in the access to transmit programs for children and others. Additionally, the control and information menus allow a user to override a maximum classification limit previously selected in the entry of authorization data such as user identification and password. When executing the process of Figure 4 and after the start in step 300, the controller 60 in step 303 starts programming the program display (including tuning and acquisition) recording or playback. The controller 60 starts programming in response to a user programming command via the program guide interface of Figure 3, as discussed above. The controller 60 in step 305 configures the units 13, 15 and 17 (Figure 1) and the decoder elements 100 to receive program guide information composed of a first transmission source. The composite program guide information contains program description and other information that supports the pooling and decoding of packet data that constitute individual programs produced by multiple different transmission sources. The controller 60 configures the processor 13, the demodulator 15 and the decoder 17 to receive the data format and channel frequency specific to the transmission channel provided by the first transmission source. It is so, in step 305, the controller 60, in conjunction with the unit 22, acquires composite program guide information containing program-specific information including a classification of the program content for the desired program of the first transmission source. Also, in step 305 the controller 60 stores the program-specific information in the internal memory and the step 310 retrieves the content classification of the desired program from a content warning descriptor included in an Event Information Table of the specific information of the stored program. The controller 60 determines the classification system of the recovered content classification (ie, whether the desired program is classified in accordance with a V-chip or a system compatible with M PAA, for example) of a Classification Region Table acquired. of the specific information of the stored program. In step 315, the controller 60 compares the classification of the content of the recovered program with a maximum ranking level limitation contained in a specific classification profile predetermined by the user. The classification level limit determines the maximum content rating of the program to which the current user of the decoder system 100 has authorized access. If the content classification of the desired program does not exceed the maximum content classification level, the controller 60 schedules the processing of the desired program in step 315. The classification of the content of the retrieved program and the level of content classification level maximum are compatible with a content classification system included in the Classification Region Table previously stored. A classification system based on exemplary age is shown in the program guide of Figure 3 (articles 860-872) and comprises the ratings TV-M, TV-14, TV-PG, TV-G, TV-Y7, TV-Y A number of problems may occur when using content ratings from a composite program guide (or other source of classification information) when programming program processing in the manner disclosed in steps 303-315. Specifically, problems may arise because a) the classification of the content provided in the composite guide provided by the first source of transmission may be inaccurate, and b) the verification of the user authorization made in step 315 may be rendered invalid by a variety of reasons. Verification can be made invalid, for example, because a user subsequently cancels and alters the program guide limit level or by a subsequent reclassification of the content of the desired program. Consequently, the controller 60 in step 320 acquires a second content classification of the desired program of program-specific information provided by the transmission source of the desired program. The classification of the content of this second source of transmission is reasonably acquired near the time of transmission of the program to allow a second current and reliable validation of the user's authorization to access the desired program. In step 325, the controller 60 converts the classification of the content acquired from the second source (the transmitter or the desired program) to be compatible with the content classification system used by the first source (the transmitter of the composite guide) . The controller 60 converts the content classification using predetermined map formation information for mapping content ratings from one transmission source to a classification system for another source. In step 330, if the classifications acquired from the first and second transmission sources are different, the controller 60 selects among them. Once selected, the classification of the content is used in the additional processing and can be used by the controller 60 in step 330 to update an existing different classification such as a classification displayed in the program guide of Figure 3., for example. The controller 60 in step 330 selects a program-specific information parameter of the transmission source considered to be the most reliable and accurate considering a) the type of parameter being selected (a content classification in this example), and b) the time and stage in the processing scheme to which the parameter is being processed. A program-specific information parameter of a transmission source can be considered more reliable at a particular point in time than an equivalent parameter from another source. Consequently, the selection of the parameter can be conveniently varied based on the source of the parameter and the processing stage and time at which it is acquired. In other embodiments, the step of classification conversion 325 may be necessary and may alternatively be used to convert a classification to the source system or to a different third system. It is advisable in the conditioning of access based on program content classifications to select the classification of the content that is: a) be provided from the source of transmission of the desired program, and b) is the classification most recently acquired, especially if the classification is It acquires substantially close to the time of transmission of the desired program. In step 335, the controller 60 uses the classification selected in step 330 to perform a second validation of the user's authorization to access the desired program in the manner described in relation to step 31 5. Specifically, the controller 60 compares the classification of the content of the retrieved schedule with the limit of the maximum classification level contained in the user's predetermined specific classification profile. After successful validation, the controller 60 in step 337 initiates the processing of the desired program by configuring the demultiplexer 22 with the PIs Ds to identify and acquire the packets comprising the data streams that constitute the desired program. The decoder 1 00 processes the identified packets of the desired program for display, recording or reproduction in the manner previously described in relation to Fig. 2. The process of Fig. 4 ends in step 340. The process of FIG. 4 is also used to condition access to analog video programs and in the acquisition and processing of program content ratings of the vertical blanking intervals of analog video signals compatible with NTSC. Accordingly, steps 303-320 similarly include programming analog video processing and tuning to analog video sources to derive content classifications (e.g., V-chip compatible ratings) from horizontal or vertical blanking intervals compatible with NTSC. Additionally, the mapping, selection, validation and processing of steps 325-337 uses classifications derived from analog video signal as well as information specific to the digital program. Figure 5 shows a method for generating program-specific information that incorporates information on the content classification of the program and system timing, according to the invention. The method can be employed in encoder number to transmit video data such as the data received from the antenna 10 of Figure 1 or the method can be employed in a decoding unit such as in the controller 60 of Figure 1 in a mode of storage, for example. In a storage mode of the system of Figure 1, the corrected output data of the unit 17 is processed by the decoder 100 to provide a data stream compatible with M PEG for storage. In this mode, a program for storage by a user is selected via the remote unit 70 and the interface 65. The processor 22, in conjunction with controller 60 forms program-specific and condensed system information including data from System Time Table, Master Guide Table, Channel Information Table, Event Information Table, Extended Text Table and Region Table of Classification that contain the previously described convenient aspects. The condensed information supports the decoding of the selected program for storage but excludes unrelated information. The controller 60, in conjunction with the processor 22 forms a composite data stream compatible with MPEG containing packet content data of the selected program and specific information of the associated condensed program. The composite data stream is produced as an output for the storage interface 95. The storage interface 95 damps the composite data stream to reduce clearances and the bit rate variation in the data. The resulting buffered data is processed by the storage device 90 to be suitable for storage in the medium 105. The storage device 90 encodes the buffered data stream of the interface 95 using known error coding techniques such as channel coding. , de-interleaving and encoding of Reed Solomon to produce a coded stream of data suitable for storage. The unit 90 stores the resulting coded data stream by incorporating the program-specific information condensed in the medium 105. An encoder employs the method of Figure 5 to generate program-specific and system-specific information including data from the System Time Table, Table of Master Guide, Channel Information Table, Event Information Table, Extended Text Table and Classification Region Table and descriptors for each transmitter and to combine the information into a composite data stream. The generated information can be transmitted to a decoder system such as the system of Figure 1 for, for example, reception by antenna 10 and subsequent decoding as described above, after the start in step 400 of Figure 5, the Data from the System Time Table, Master Guide Table, Channel Information Table, Event Information Table, Extended Text Table and Classification Region Table and descriptors for each transmitter are generated in steps 405 and 410. Specifically , a Channel Information Table is generated in step 405. The Channel Information Table contains program identification information and channel that allows the acquisition of available programs and transmission channels produced by an individual transmitter. The Channel Information Table incorporates channel identification numbers and packet identifiers to identify data streams in individual packets that constitute individual programs that are to be transmitted on particular channels. The generated Channel Information Table also incorporates items related to listed program channels including a program number, a language code identifier, and a stream type identifier, as described above in relation to Figure 1. In step 410, an Event Information Table is generated containing program guide information including descriptive lists of programs (events) that are received in the channels listed in the Channel Information Table. The Event Information Table is generated to include a content warning descriptor containing selected and processed program content classifications of the classification information provided by multiple transmission sources in the manner described in relation to Figure 4. The Table Event Information associates a specific program with a specific classification. An Extended Text Table and a Classification Region Table are also generated in step 410. The Extended Text Table contains text messages describing programs, for example, and the Classification Region Table contains classification information of the program content for various classification systems as described above. In step 410, a Master Guide Table is also generated that contains data identifiers that allow the identification and conjunction of the information of the Channel Information Table, the Event Information Table and the Classification Region Table. The Master Guide Table also transfers information on the size of the table for the Channel Information Table, Event I nformation Table, Extended Text Table and Classification Region Table previously generated. A System Time Table is also generated in step 410 and contains a time reference indication and associated correction data sufficient for a decoder to establish a time of program transmission by the program transmitter. In step 415, the data of the System Time Table, Master Guide Table, Channel Information Table, Event Information Table, Extended Text Table and Classification Region Table and the descriptors generated for each transmitter in the Steps 405 and 410 are formed into program-specific information and composite information for multiple transmission sources. The specific information of the program and the composite system is conveniently formed to associate individual System Time Table time references with their corresponding transmission sources. In step 420, the composite information produced in step 415 is combined with representative audio and video program components for multiple channels and is formatted in a transport stream for output. In step 423, the output transport stream is further processed to be suitable for transmission to another device such as, for example, a receiver, video server, or storage device for recording in a storage medium. The processes performed in step 423 include known coding functions such as Reed-Solomon data compression coding, interleaving, mixing, grid coding and carrier modulation. The process is completed and terminated in step 425. In the process of Figure 5, multiple Channel Information Table, Event Information Table, Extended Text Table and Classification Region Table can be formed and incorporated into the information. specific to the program to accommodate expanded channel numbers. The architecture of Figure 1 is not exclusive. Other architectures may be derived in accordance with the principles of the invention to achieve the same objectives. Additionally, the functions of the decoder elements 100 of Figure 1 and the process steps of Figures 2, 4 and 5 may be implemented in whole or in part in the programmed instructions of a microprocessor. Additionally, the principles of the invention apply to any form of Electronic Program Guide compatible with MPEG or non-MPEG. A data stream formed in accordance with the principles of the invention can be used in a variety of applications including, for example, video server or personal computer communication via telephone lines. A stream of program data with one or more video, audio and data components formed to incorporate program and system-specific information in accordance with the principles of the invention can be recorded on a storage medium and transmitted or retransmitted to other servers , personal computers or receivers.