MXPA00000344A - A system for forming and processing program specific information containing text data for terrestrial, cable or satellite broadcast - Google Patents

Abstract

Packetized program information used in video processing and storage medium formats includes multiple text strings. A decoder (100) decodes packetized program information containing multiple text strings associated with a program. The decoder (100) determines from a first indicator in the packetized program information a type of coding and compression employed in encoding a first text string. The decoder (60, 30) decodes the first text string with a decoding function selected in accordance with the determined type of coding and assembles (60, 30) decoded text string elements to form an output text string.

Description

TJN SYSTEM TO FORM AND PROCESS SPECIFIC PROGRAM INFORMATION CONTAINING TEXT DATA FOR TERRESTRIAL, CABLE OR SATELLITE TRANSMISSION This invention relates to the formation of program guides, system information and program-specific information for MPEG-compatible processing. In video transmission and processing applications, digital video data is typically coded to conform to the requirements of a known standard. One of these widely adopted standards is the MPEG2 image coding standard (Groups of Experts in Moving Images), hereinafter referred to as the "MPEG standard". The MPEG standard is composed 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). The data encoded for the MPEG standard is in the form of a packet data stream that typically includes the data content of many channels and programs (e.g., the content corresponding to cable television channels 1-125). In addition, several services and digital channels can occupy the frequency spectrum previously occupied by a single analog channel. A 6 megahertz bandwidth previously assigned to an NTSC compatible analog transmission channel can now be divided into several digital subchannels offering a variety of services. For example, the transmission spectrum for the radio frequency channel 13 can be assigned to subchannels that include a main program channel, a financial service channel that offers share quotas, a sports news service channel and a shopping channel and interactive. In addition, both the number of subchannels transmitted and the individual subchannel bandwidth can be changed dynamically to suit constant transmission programming requirements. In this digital video system the proliferation of the amount of services being transmitted and the increased variety of its content, as well as the ability of a transmitter to dynamically vary the number and bandwidth allocated to these channels raises several problems. Specifically, the increase in the number of transmission channels may increase the difficulty of tuning and prolong the time required to acquire a selected program channel. In addition, as the number of channels increases the same thing happens with the amount of program-specific auxiliary information required to decode the transmitted program data. The program-specific auxiliary information includes data used to identify and assemble packages comprising selected programs and also includes a program guide and text information associated with the transmitted program data. The increased amount and variety of auxiliary information transmitted poses an additional burden on the available transmission bandwidth and decoding of the receiver and storage resources. In addition, the numbering of channels in this digital video system may present a problem. This is because a transmitter may not want to lose an original analog NTSC transmission channel number even when the transmitter is transmitting several program channels in the frequency spectrum previously occupied by the single analog program channel. The transmitter can have a significant investment in the channel number as a brand identification for example Fox 5 Channel 13. These problems and the problems arising therefrom are attacked by the system according to the present invention. A decoder decodes the program information into packets containing multiple text strings associated with a program. The decoder determines from a first indicator in the information of packaged programs a type of coding and compression used to encode a first string of text. The decoder decodes the first text string with a decoding function selected according to the particular type of coding and assembles the decoded text string elements to form an output text string. BRIEF DESCRIPTION OF THE DRAWINGS In the drawings: Figure 1 is a block diagram of a digital video receiver apparatus for demodulating and decoding signals transmitted in accordance with the principles of the invention. Figure 2 shows a master guide table (MGT) format for use to convert program-specific information, according to the invention. Figure 3 shows a channel information table (CIT) format for use to convey program-specific information that incorporates the dual program channel identification numbers according to the invention. Figure 4 shows a service location descriptor (SLD) format for use to convey program-specific information that incorporates the program map information, according to the invention. Figure 5 shows a text format of program-specific information for use to convey text information related to programs according to the invention. Figure 6 shows a schema for assigning a text message identifier as used in the text format of Figure 5. Figure 7 shows a multiple compressed text string format for use to convey text information related to the text. program, according to the invention. Figures 8 and 9 show exemplary indicator definitions for compression and coding indicators within the compressed text multiple strings format of Figure 7. Figure 10 shows a method for generating program specific information according to the present invention.

Figure 1 is a block diagram of a digital video receiver system for demodulating and decoding signals transmitted in accordance with the principles of the invention. Although the described system is described in the context of a system for receiving video signals incorporating program-specific information that includes program guide data in MPEG-compatible format, it is exemplary only. Program-specific information can be of a variety of types. For example, you can meet the requiremeof the program-specific information (PFI) specified in section 2.4.4 of the MPEG systems standard or can comply with the standard of high definition television (HDTV) Digi tal Television Standard for AHTV Transmission of April 12, 1995, prepared by the Committee of Advanced Television Systems of the United States (ATSC) or other ATSC standards. Alternatively, it can be formed according to the requiremeof the owner or adapted to the client of a particular system. The principles of the invention can be applied to terrestrial, cable, satellite, and Internet transmission systems or computer networks in which the type of coding or modulation format can be varied. These systems may include, for example, systems not compatible with MPEG, which involve other types of coded data streams and other methods for conveying program-specific information. In addition, although the described system is described as processing transmission programs, this is only exemplary. The term "program" is used to represent any form of data in packets such as audio data, telephone messages, computer programs, Internet data or other communications, for example. In general, in the video receiver system of Figure 1, a modulated transmission bearer with signals carrying associated audio, video and data data representing broadcast program content are received by the antenna 10 and processed by the unit. 13. The resulting digital output signal is demodulated by the modulator 15. The demodulated output of the unit 15 is decoded by lattice, is mapped into data segmeof one byte in length, deinterleaved and the error is corrected by Reed-Solomon by the decoder 17. The corrected output data of the unit 17 is in the form of a transport data stream compatible with MPEG containing multiplexed data, audio, and video componerepresentative of the program. The transport stream of the unit 17 is demultiplexed into audio, video and data componeby the unit 22 which are further processed by the other elemeof the decoder system 100. In one embodiment, the decoder 100 provides decoded MPEG data for reproduction in visual and audio display in units 50 and 55 respectively. In another embodiment, the transport stream of the unit 17 is processed by the decoder 100 to provide a data stream compatible with MPEG for storage in the storage medium 105 via the storage device 90. A user selects to see either a television channel or a menu on the screen, such as a program guide, using a remote control unit 70. The processor 60 uses the selection information provided from the remote control unit 70 via the interface 65 to configure appropriately the elemeof Figure 1 to receive a desired program channel to visualize it. The processor 60 comprises the processor 62 and the controller 64. The unit 62 processes (i.e. analyzes syntax, interleaves and assembles) program-specific information including the program guide and the system information and the controller 64 performs the control functions remaining required to operate the decoder 100. Although the functions of the unit 60 can be implemented as separate eleme62 and 64 as depicted in Figure 1, alternatively they can be implemented within a single processor. For example, the functions of units 62 and 64 can be incorporated into the programmed instructions of a microprocessor. The processor 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. The units 13, 15, 17 and the subunits within the decoder 100 are individually configured for the type of input signal by the processor 60 by setting control register values within these elements using bidirectional data and a control signal bus C The transport stream provided to the decoder 100 comprises data packets containing program channel data and program-specific information. The unit 22 directs the program-specific information packets to the processor 60 which analyzes syntax, interleaves and assembles that information into hierarchically configured tables. The individual data packets comprising the program channel selected by the user are identified and assembled using the specific information of assembled programs. The program-specific information contains conditional access, network information, and identification and link data that allow the system of Figure 1 to tune to a desired channel and assemble data packets to form complete programs. The program-specific information also contains auxiliary program guidance information (for example, an electronic program guide-EPG) and descriptive text related to the transmitted programs as well as data that supports the identification and assembly of that auxiliary information. The specific information of the program is assembled by the processor 60 in multiple tables arranged hierarchically and interlaced. An exemplary hierarchical table arrangement is a master guide table (MGT), a channel information table (CIT), event information tables (EIT), and optional tables such as extended text tables (ETT). The master guide table contains information to acquire program-specific information conveyed in other tables 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) receivable in the channels listed in the channel information table. The extended text table contains text messages that describe programs and program channels. The specific information of additional programs that describe and supplement items within the hierarchical table is transported within the information descriptor elements. The program-specific information acquired by processor 60 via unit 22 is stored within the internal memory of unit 60. Considering Figure 1 in detail, a modulated carrier with signals carrying audio, video and associated data representative of the program received. by the antenna 10, they are converted into digital form and processed by the input processor 13. The processor 13 includes a radio frequency (RF) tuner and intermediate frequency (IF) mixer and amplification stages to convert the input signal into a lower frequency band suitable for later processing. In this exemplary system, the input signal received by the antenna 10 contains 33 physical transmission channels (PTC 0-32). Each physical transmission channel (PTC) is assigned a bandwidth of 6 megahertz and contains, for example, up to 6 subchannels.

It is assumed for exemplary purposes that a video receiver user selects a sub-channel (SC) to view it using a remote control unit 70. The processor 60 uses the selection information provided from the remote control unit 70 via the interface 65 for properly configuring the elements of the decoder 100 to receive the physical transmission channel corresponding to the selected sub-channel SC. Continuing the conversion, the output signal from unit 13 of the selected physical transmission channel has a bandwidth of 6 megahertz and a center frequency in the range of 119-405 megahertz. In the following discussion, a radiofrequency channel, a physical transmission channel (PTC) refers to a transmitter transmit channel band that spans one or more subchannels (also called virtual or logical channels). The processor 60 configures the radio frequency tuner and the intermediate frequency mixer and the amplification stages of the unit 13 to receive the selected physical transmission channel. The output of the converted frequency for the selected physical transmission channel is demodulated by the unit 15. The primary functions of the demodulator 15 are the recovery and tracking of the carrier frequency, the recovery of the clock frequency of the transmitted data, and the recovery of the same video data. The unit 15 also retrieves the sampling and synchronization clocks corresponding to the transmitter clocks that are used to time the operation of the processor 13, the demodulator 15 and the decoder 17. The output recovered from the unit 15 is provided to the decoder 17. The output of the scrambler 15 is mapped into data segments of one byte in length, deinterleaved and the error corrected by Reed-Solomon according to principles known by means of the unit 17. In addition, the unit 17 provides a validity of error correction towards forward (FEC) or lock indication to processor 60. Reed-Solomon error correction is a known type of forward error correction. The forward error correction blocking indication indicates that the Reed-Solomon error correction is synchronized with the data that is being corrected and a valid output is being provided. It will be noted that the demodulator and decoder functions implemented by the units 13, 15 and 17 are known individually and are generally described, for example, in the reference text Digi tal Communication, Lee and Messersch idt (Kluwer Academic Press, Boston, MA , USA, 1988). The corrected output data of unit 17 is processed by the MPEG compatible transport processor and demultiplexer 22. Individual packets comprising either the particular program channel content, or program specific information, are identified by their program identifiers. package (PID). The processor 22 separates data according to the type based on analysis of the packet identifiers (PID) contained within the packet header information and provides synchronization and error indication information used in the subsequent decompression of video, audio and data. The program-specific information is in the form of hierarchically arranged tables that include the master guide table, the channel information table, the event information table, and the extended text table along with supplementary descriptive information. The PID identifying packets comprising the data of the master guide table is predetermined and stored within the processor 60 in the internal memory. In addition, the master guide table transports the PIDs that identify the data from the channel information table, the event information table, and the extended text table and transports other information indicating the size of these tables. The processor 60 monitors the master guide table for updates and to identify any changes in the PIDs of the table sizes. Thus, after the processor 60 determines from the forward error correction blocking indication provided by the unit 17 that valid data is being provided to the transport processor 22, the master guide table can be acquired without additional PID information . Using the control signal C, the processor 60 configures the transport processor 22 to select the data packets comprising the specific information of the remaining program including data from the table of .Channel information the event information table and the table of information. extended text. The processor 22 matches the PIDs of the incoming packets provided by the unit 17 with pre-loaded PID values in control registers within the unit 22 by the processor 60. In addition, the processor 60 has access, analyzes the syntax and assembles the packets of specific information of programs captured by the processor 22 and stores the program-specific information within its internal memory. The processor 60 derives tuning parameters that include the carrier frequency of the physical transmission channel, the demodulation characteristics, and the sub-channel PID, from information specific to the acquired program. The processor 60 uses this information to configure the units 13, 15, 17 and the elements of the decoder 100 to acquire the program content of the selected sub-channel (SC). The program-specific information that includes data from the master guide table, the channel information table, the event information table, and the extended text table and the associated descriptors acquired and interspersed by the processor 60 incorporate advantageous features exemplified in the data formats presented in Figures 2-9. These features facilitate the identification, acquisition, assembly and decoding of the content of the program channel and the associated program guide data by the decoder 100 (Figure 1). The processor 60 forms a master guide table as exemplified by the data format of Figure 2 by accessing and assembling the program-specific information packets that are stored in the internal memory unit 60. The master guide table contains data identifiers, for example PID_ETT 205 and PID_PG 210 (Figure 2) that allow the assembly of the tables: channel information table, event information table and extended text table. The processor 60 uses the data identifiers of the master guide table to access and assemble the program-specific information packets to form the data from the channel information table, the event information table, and the extended text table and the associated descriptors. The processor 60 uses the channel map information of the acquired channel information table, as exemplified in Figure 3, to identify the packets comprising the SC sub-channel that the user selected to view. A user selects the subchannel SC for viewing by entering two program channel numbers via the remote control unit 70 and the interface 65. The individual program channels advantageously are assigned with both a first and a second identification number. The first identification number (a number greater than that indicated by the number_of_haz 300 in Figure 3) identifies the transmission source and the brand number of the transmitter channel, for example, Fox, Channel 13. The first identification number indicates the transmission source of a program or service and may be independent of the radio frequency channel on which the program is being transmitted. However, in other modalities the first identification number may be associated with a radio frequency transmission channel or be associated with other characteristics of the program such as a category of the program or theme for example cinema. The second identification number (a smaller number indicated by number_channel_in_haz 305 in Figure 3) identifies a sub-channel corresponding to a specific service within a group of services provided by a transmitter. The first and second identification numbers together identify a particular service as a subchannel provided by a specific transmitter. Although the selected SC sub-channel may occupy a radio frequency bandwidth within a spanning channel spectrum associated with the transmission source, neither the first nor the second identification numbers are associated with this spectrum. However, this association can be done in an alternative mode. This dual numbering system allows a transmitter to retain the brand identification of the channel through a range of dynamically assignable transmission subchannels. The dual program channel identification numbers used to select the SC subchannel may be entered by the user in a variety of ways. These may include using the remote unit 70 to select the SC sub-channel from which a hierarchical menu system displays selections of program channels in a program guide or by simple sequential number entry via the unit's keyboard 70, for example. example. The channel selection system may also encompass the use of different data entry devices such as the keyboard or discrete switches, for example. In addition, the data entry system also accommodates the entry of a single channel identification number as well as dual identification numbers. After detecting a completion command of the channel selection, the processor 60 converts a unique channel identification number entry into dual identification numbers. The processor 60 converts the unique channel identification number into dual channel identification numbers according to a predetermined conversion map. This conversion can be done using a predetermined and stored algorithm or formula. The derived dual identification numbers are used by the processor 60 to identify the packet, to tune and to identify other decoder information in the previously described manner as if both numbers had been entered by a user. The processor 60 uses the received program channel identification numbers 300 and 305 provided from the remote control unit 70 via the interface 65 to determine the physical transmission channel corresponding to the selected sub-channel SC from the information table of channels. As soon as the physical transmission channel number (article 315 in Figure 3) is determined, the processor 60 (Figure 1) configures the units 13, 15, and 17 to receive the physical transmission channel for the selected sub-channel SC. The unique program sub-channel determined for the program channel identification numbers 300 and 305 can alternatively be referred to as the service channel or virtual channel or logical channel and the channel information table can consider a table of virtual channels. In addition, as well as associating a particular physical transmission channel with a first and second sub-channel identification numbers 300 and 305 of the selected sub-channel SC, the channel information table also associates other parameters with SC. These parameters include (a) a channel_id 320 to link the selected sub-channel SC with information of the program content transmitted in the event information tables, (b) a channel-type indicator 325 that identifies whether the data of the sub-channel is analog, for example NTSC, digital video, for example ATSC or digital audio, for example ATSC audio, (c) an ETM_flag 330 indicating whether a text message is available for this sub-channel, (d) a channel name 340 and (e) a descriptor 335 for example a service location descriptor as described below. The processor 60 advantageously determines program map information, for the selected sub-channel SC of the service locator descriptor (SLD) transported with the channel information table. The map information of the service location descriptor program is exemplified by the data format of Figure 4. The service location descriptor associates the selected sub-channel SC with packet identifiers, for example article 420, used to identify streams of data in individual packets that constitute the components of a program that is being transmitted in the selected sub-channel SC. further, the service location descriptor program map information, together with the channel information table, maps the selected sub-channel SC into a program number 405, a PCR identifier (program reference 410), a code indicator 425, and a current type identifier 415 that identifies a stream as video, audio, control, auxiliary or private information, for example. The service location descriptor program map information replicates the information already present within the segment of the program mapping table (PMT) of the MPEG compliant transport stream that enters the decoder 100. However, by incorporating the service location descriptor within the channel information table, the time required for the decoder 100 to identify and acquire a program that is being transmitted on the selected sub-channel SC is advantageously reduced. This is because the channel information table and the service location descriptor provide sufficiently formatted and linked information to allow the processor 60 to directly configure and tune the system of Figure 1 to receive the selected sub-channel SC. Specifically, the channel information table and the service location descriptor directly associate the individual first and second identification numbers of the sub-channel with the PIDs to identify the data streams that constitute a program that is being transported in this sub-channel. This allows the processor 60 to configure the system of Figure 1 to receive the selected sub-channel SC without acquiring and using the information from the program map table (PMT) in the MPEG-compatible transport stream introduced into the decoder 100. In addition, the data partition, the data formatting and the data repetition frequency characteristics of the service location descriptor program map information and the channel information table can be determined independently of the information requirements of the table of MPEG program maps. The packet decoded transport stream introduced into the decoder 100 from the unit 17 contains video, audio and data representing television programs, for example, and also contains sub-image data. The sub-image data contains image elements associated with programs and user selectable channels to view including program guides, display commands, subtitling, selectable menu options or other things, for example. As such, the sub-image data includes the event information tables containing descriptive lists of programs (events) receivable in the sub-channels listed in the channel information table which also contains the extended text table containing text messages describing programs and sub-channels of programs. The processor 60 determines from the channel information table and the service location descriptor the PIDs of the video, audio and sub-picture streams that constitute the program that is being transmitted on the selected sub-channel SC. The processor 22 couples the PIDs of the incoming packets provided by the decoder 17 with PID values of the video, audio and sub-picture streams that are being transmitted on the SC sub-channel. These PID values are preloaded into control registers within the unit 22 by the processor 60. In this way, the processor 22 captures the packets that constitute the transmitted packet in the SC sub-channel and the video, audio and audio stream forms. MPEG-compatible sub-images to output to the video decoder 25, the audio decoder 35 and the sub-picture processor 30 respectively. Video and audio streams contain data from compressed video and audio that represent the content of the selected SC subchannel program. The sub-image data contains the information of the event information table and the extended text table associated with the content of the SC sub-channel program. The decoder 25 decodes and decompresses the MPEG compatible packet video data from the unit 22 which provides data of representative decompressed program pixels to the NTSC 45 encoder via the multiplexer 40. Similarly, the audio processor 35 decodes the audio data in packets from the unit 22 and provides decoded and amplified audio data, synchronized with the decompressed associated video data, to the device 55 for audio playback. The processor 30 decodes and decompresses the sub-image data received from the unit 22. The sub-image data decoded by the processor 30 includes text messages (extended text messages-ETM) in an extended text table in the format of exemplary data presented in Figure 5. The text messages conveyed in the extended text table of Figure 5 are advantageously split into specific time periods. Segmented text messages describe programs that are presented in a period of specific duration and start time such as blocks of 3 hours that start from 12 a. . at 3 p.m., 6 p.m., et cetera. Indicators defining the duration and start time applicable to transported text messages are included in the master guide table of Figure 2 (article of duration 215 and article of application_time 220 of Figure 2 respectively). A text message (eg extended text message 505) is transported together with a message identifier (ETM_id 510) of the format in Figure 5. The decoder 100 (Figure 1) is able to acquire, process and store text messages more efficiently descriptive of the program matches in periods of time of specific duration, of what is possible in the absence of this segmentation. This is because segmented text messages exclude information that is presented outside of the specific time period and consequently are less than non-segmented text messages. Therefore, segmented text message data occupies less storage space and can be acquired and processed more quickly than larger blocks of non-segmented data. In addition, the data format of Figure 5 allows a user to acquire text message data for a selected sub-channel SC or a group of sub-channels of selected programs. This allows the identification, acquisition and decoding of the text message data of the decoder 100 to focus on programs and sub-channels of interest to a user and reduces the acquisition of information from redundant text messages. A text message transmitted in an extended text table may contain channel information or program information (events). Figure 6 shows an exemplary format for assigning a text message identifier ETM_id 510 of Figure 5 which identifies the type of text message for example, if the text message contains channel information (article 610 of Figure 6) or program information (article 605 of Figure 6). The text message identifier 510 (Figure 5) also identifies the source for example the sub-channel to which the text message belongs. A text message 505 conveyed in the extended text table of Figure 5 is compressed and formatted according to the multiple compressed text string format of Figure 7. The compressed text string format advantageously incorporates indicators that facilitate the identification and decoding of multiple compressed text strings by the processor 30 in the decoder 100 of Figure 1. The processor 30 decodes the text string 505 (Figure 5) received from the unit 22 (Figure 1) by determining the compression characteristics, coding_and language of the text string of indicators 705, 710 and 715 (Figure 7) respectively. Similarly, the processor 30 decodes the received text string by applying a decoding function that interprets the characteristics of the text according to a character encoding set selected using the flag 710 and a set of language codes selected using the flag 715. In addition, the processor 30 determines the number of text strings to be processed and the number of bytes in each text string for the flags 725 and 720 respectively. Figure 8 shows an exemplary indicator definition for the compression indicator 705 within the multiple compressed text string format of Figure 7. It will be noted that the compression indicator 705 may indicate that no compression function was used within a chain of text. In this case, the processor 30 does not apply a decompression function to the text string received from the unit 22. Figure 9 shows an example indicator definition for the code indicator 710 within the format of the multiple compressed text string of Figure 7. The processor 30 assembles and formats the decompressed and decoded text string elements of the text string 505 (Figure 5) to form a decoded text string for output in an on-screen display (OSD) and generator. graphs 37 (Figure 1). The unit 37 interprets and formats the text string character data of the unit 30 and generates text mapped in formatted pixels and graphics for the presentation in the unit 50. The text data and graphics mapped in formatted pixels can represent a guide of program or other type of menu or user interface for the subsequent deployment in unit 50. Unit 37 also processes the event information table, the extended text table and other information to generate data mapped in pixels that represent, subtitle, control and information menu displays that include selectable menu options, and other items, for presentation in unit 50. The control and information displays allow the selection of the function and the introduction of operation parameters of the device for the operation of the user of the decoder 100. The text and graphics produced by the display generator in the display 37 are generated in the form of map data in pixels superimposed under the address of the processor 60. The overlay pixel map data of the unit 37 is combined and synchronized with the data representative of decompressed pixels of the MPEG decoder 25 in the encoder 45 via the multiplexer 40 under the direction of the processor 60. The combined pixel map data representing a video program in the SC sub-channel together with associated sub-picture text message data is encoded by the NTSC 45 encoder and output in the device 50 for display. 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 MPEG for storage. In this mode, a program is selected for storage by a user via a remote unit 70 and the interface 65. The processor 22, together with the processor 60 forms the condensed program-specific information that includes data from the master guide table, the information table of channels, the table of information of events and the table of extended text and descriptors that contain the advantageous characteristics previously described. The condensed specific information of the program supports the decoding of the selected program for storage but excludes unrelated information. The processor 60, together with the processor 22 forms a composite MPEG compatible data stream containing packet content data of the selected program and condensed specific information of the associated program. The composite data stream exits to the storage interface 95. The storage interface 95 stores the composite data stream to reduce gaps and the bit rate variation in the data. The resulting stored data is processed by the storage device 90 to be convenient for storage in the medium 105. The storage device 90 encodes the buffer data stream of the interface 95 using known error coding techniques such as channel coding, interleaving and Reed Solomon coding to produce a convenient coded data stream for storage. The unit 90 stores the resulting coded data stream that incorporates the condensed specific information of the program into the medium 105. Figure 10 shows a method for generating program-specific information that includes data from the master guide table, the channel information table , the table of information of events and the table of extended text and descriptors that contain the advantageous characteristics previously described. The method can be employed in an encoder to transmit video data such as data received by the antenna 10 of Figure 1 or the method can be employed within a decoder unit such as within the processor 60 of Figure 1. After the start in step 800 of Figure 10, a channel information table is generated in step 810. The channel information table contains subchannel and program identification information that allows the acquisition of available transmission programs and subchannels. The channel information table incorporates first and second subchannel identification numbers and a service location descriptor that contains packet identifiers to identify individual packet data streams that constitute individual programs to be transmitted in particular subchannels. The generated channel information table also incorporates items related to sub-channels of listed programs that include a program number, a PCR (Program Clock Reference) identifier, a language code indicator, a current type identifier, as described previously in relation to Figure 1. In step 815, an event information table is generated containing program guide information that includes descriptive lists of programs (events) receivable in the subchannels listed in the channel information table . In step 820, an extended text table is generated containing text messages describing programs, for example. Each text message is split into specific time periods. The duration and time of application of the segmented text message data are also defined by the indicators in the same extended text table. The text message data is encoded and compressed according to known techniques and transported in the extended text table along with indicators defining the compression, coding and language characteristics employed. The extended text table is also generated to include indicators that define the number of text strings to be processed and the number of bytes in each text string. In step 822, a master guide table is generated that contains data identifiers that allow the identification and assembly of information from the channel information table, the event information table and the extended text table. The master guide table also carries information about the size of the table for the channel information table, the table of event information and the extended text table previously generated. In step 825, program specific information is formed which includes data from the master guide table, the channel information table, the event information table and the extended text table and descriptors generated in steps 805-822. In step 830, the program-specific information together with representative video and audio program components for multiple sub-channels is formatted in a transport stream for output. In step 835, the outgoing transport stream is further processed to be convenient for transmission to another device such as a receiver, video server, the storage device for recording it in a storage medium., for example. The processes performed in step 835 include known coding functions such as data compression, Reed-Solomon coding, interleaving, mixing, lattice coding, and bearer modulation. The process is completed and terminated in step 840. In the process of Figure 10, multiple tables can be formed: channel information table, event information table and extended text table and incorporated into the program-specific information with In order to accommodate expanded numbers of subchannels.

The architecture of Figure 1 is not exclusive. Other architectures may be derived in accordance with the principles of the invention to carry out the same objectives. In addition, the functions of the decoder elements 100 of Figure 1 and the process steps of Figure 10 can be implemented entirely or in parts within the programmed instructions of a microprocessor. In addition, the principles of the invention apply to any form of electronic program guide compatible with MPEG or not compatible with MPEG. A data stream formed in accordance with the principles of the invention can be used in a variety of applications including a video server or PC type communication via telephone lines, for example. A stream of program data with one or more video, audio and data components formed to incorporate program-specific information in accordance with the principles of the invention can be recorded on a storage medium and transmitted or retransmitted to other servers, the computers personal or receivers. In addition, any reference herein to "bandwidth" will be construed broadly as including bit rate capability if it is not limited to a frequency spectrum, for example.

Claims (20)

1. CLAIMS 1. Apparatus for decoding a package information program containing multiple text strings associated with a program, comprising: means for determining (60, 30) from a first indicator (705, 710) in the program information in package a type of coding and compression used to encode a first text string; means for decoding (60, 30) the first text string with a decoding function selected according to the particular type of coding; and means for assembling (60, 30) the decoded text string elements to form an output text string. The apparatus according to claim 1, wherein the means for decoding comprises means for decompressing (60, 30) the first text string with a decompression function selected according to the type of compression (705). The apparatus according to claim 1, wherein the first indicator (705) indicates that no compression function is used to encode the first text string, and the means for decoding comprises means for interpreting codes in the first string of text to produce text characters. The apparatus according to claim 1, including means for determining from a second indicator (715) in the packet program information a type of language used in the first text string. The apparatus according to claim 4, including means for decoding the first decoded text string with a decoding function selected according to the type of language determined. The apparatus according to claim 1, including means for determining from a second indicator (725) in the packet program information the number of text strings to be decoded. The apparatus according to claim 1, including means for determining from a text mode coding indicator (710) in the packet program information a type of character interpretation to be used to interpret the decoded text. The apparatus according to claim 1, including means for determining from a second indicator (720) in the packet program information the number of bytes of text in a text string to be decoded. The apparatus according to claim 1, wherein the decoded text string represents at least one of (a) descriptive information of the program or channel, (b) a name of the transmission channel, (c) information of the region geographic, (d) classification information of the program content (e) information of the table of the program map or channel, (f) information of the description of the program or event table, and (g) information of the table of Geographical classification regions. 10. A storage medium containing digital data compatible with MPEG that represents video information comprising: a packaged video program; information containing, a) multiple text strings (505) associated with _the packaged video program, b) a first indicator (710) to indicate a type of coding used to encode a first string of text, the first indicator being convenient for use to select a decompression function to be used to decode the first text string; and c) information (720, 725) convenient for use to assemble the elements of the decoded text string to form an output text string. 11. A storage medium according to claim 10, wherein the first indicator also indicates that no decompression function will be used to encode the first text string. 12. An apparatus for generating program-specific information suitable for inclusion in the packaged video program information, the program-specific information includes multiple text strings associated with a video program, the apparatus comprising: means for forming text strings that decode the information (60, 22) to decode multiple strings (505), including information of decoding, a) a first indicator (705) indicating a type of compression used to encode a first text string to select a decoding function to be used to decode the first text string; and b) information (720, 725) convenient for assembling the elements of the decoded text strings to form a decoded text string; c) elements for incorporating (60, 22) the decoding information of the text string into program-specific information for output. The apparatus according to claim 12, wherein the first indicator indicates that no decompression function is to be used to decode the first text string. The apparatus according to claim 12, wherein the decoding information of the text string includes a language type indicator (715) indicating a language used in a first text string. The apparatus according to claim 12, wherein the decoding information of the text string includes a second indicator (720) indicating a number of text strings to be decoded. The apparatus according to claim 12, wherein the decoding information of the text string includes an indicator of the text mode coding (710) indicating a type of character interpretation to be used to interpret the decoded text. The apparatus according to claim 12, wherein the decoding information of the text string includes a second indicator (720) indicating a number of bytes of text in a text string to be decoded. 18. The apparatus according to claim 12, wherein the first text string represents at least one of (a) descriptive information of the program or channel, (b) a name of the transmission channel, c) information of the geographical region, ( d) program content classification information, (e) information from the program or channel maps table, (f) information from the description of the program or event table, and (g) information from the table of regions of geographic classification. 19. A method for decoding information from video programs into packages containing multiple text strings associated with a program, comprising the steps of: determining from a first indicator (60, 30), in the program information video package a type of coding used to encode a first string of text; decompressing (60, 30) the first text string (505) with a decompression function selected according to the particular type of compression; and assembling (60, 30) the elements of the decoded text string to form an output text string. 20. A method to generate program-specific information convenient for inclusion in the information of packaged video programs, the specific information of the program includes multiple text strings associated with a video program, the method comprises the steps of: forming information decoding text strings (60, 22) for decoding multiple text strings (505), including the information, a) a first flag (705) indicating a type of compression used to encode a first string to select a function of decompression to be used to decode the first text string; and b) information (720, 725) convenient for use to assemble decoded text string elements to form a decoded text string; and incorporating (60, 22) the decoding information of the text string into a program-specific information for output.