KR20000076404A - Extracting data sections from a transmitted data stream - Google Patents

Abstract

A method is provided for storing at least one of a plurality of MPEG sections in an MPEG data stream, the MPEG section having at least one MPEG section characteristic. An MPEG data stream is received and one MPEG section is filtered from the MPEG data stream in accordance with at least one MPEG section characteristic. MPEG sections are stored consecutively.

Description

Extracting data sections from the transmitted data stream {EXTRACTING DATA SECTIONS FROM A TRANSMITTED DATA STREAM}

Although not intended to be limiting, especially in satellite television systems, the emergence of digital transmission systems that have primarily focused on broadcasting television signals has developed the possibility of using such systems for other purposes. One of them is to provide interaction with the end user.

One way to do this is to apply to a receiver / decoder where the television signal is received. The code for the application can be stored permanently in the receiver / decoder. However, this may be somewhat limited. Preferably, the receiver / decoder should be able to download the code for the required application. In this way, more diversity may be provided and applications may be updated as required without any action on the user side.

In computer systems, especially systems in which computer systems are incorporated into any larger system, such as a receiver / decoder for digital television, the amount of memory is often limited. This means that the memory should be configured so that the use of memory space by the various functions required by the system can be minimized. It may also be necessary to minimize the time required to access at least some section of memory.

Thus, the present invention is in particular concerned with downloading, but not limited to, only the data specifically required by the application into the memory of the receiver / decoder.

The present invention relates to an apparatus and method for storing one or more transmitted data stream portions, such as MPEG bitstreams comprising video and audio television data in addition to the data portion.

1 shows the overall structure of a digital television system according to a preferred embodiment of the present invention.

2 shows an interactive system structure of a digital television system.

3 shows the file arrangement of the modules to be decoded into the memory of the interactive receiver / decoder.

4 shows the arrangement of each section.

5 shows the arrangement of memory capacity of an interactive receiver / decoder memory.

6 is a schematic diagram of a receiver / decoder interface.

7 shows the structure of the software in the receiver / decoder.

8 shows the structure of a receiver system for downloading sections from an MPEG data stream.

9 shows the configuration of the bytes in the section used by the hardware prefilter.

10 shows an example of a hardware filter mask array and a hardware filter value array of hardware filters.

Figure 11 shows the configuration of the bytes in the section used by the software prefilter.

12 shows an example of table loading.

13 shows an example of the configuration of sections in a group of sections.

14 shows an example of following mode download of a group of sections.

15 shows an example of presiding mode download of a group of sections.

16 shows the field configuration in a descriptor of a group of sections.

17 illustrates the field configuration in the descriptor of the sections table.

A first aspect of the invention provides a method of storing at least one section having a section characteristic of at least one of a plurality of sections of a transmitted data stream, the method comprising:

Receiving a data stream;

Filtering the one section from the data stream according to the at least one section characteristic; And

Storing the one section.

This filtering step ensures that only the sections required by the application are loaded into the memory of the receiver / decoder.

In a preferred embodiment, the filtering step is:

Specifying at least one filtering characteristic each including a filtering criterion and a value for the filtering criterion;

Comparing each section characteristic with each filtering characteristic; And

Filtering the one section from the data stream when each section characteristic matches each filtering characteristic.

A second aspect of the invention provides a method of storing a plurality of sections of a data stream transmitted using the method, each of which is stored in a respective memory location.

Preferably, this method is:

Designating at least one data filtering characteristic each including a data filtering criterion and a value for the data filtering criterion;

Comparing each data filtering characteristic with data stored in each stored section; And

When the data stored in the stored section does not match each data filtering characteristic, allowing the stored section to be replaced in the memory.

Advantageously, the method further comprises supplying a section identification signal when said data stored in said section matches said respective data filtering characteristic.

The section identification signal preferably comprises the storage address of said one section.

In a third aspect, the present invention provides a method of storing a group of sections, in which sections are transmitted periodically in a data stream, each group comprising a first section and a last section, in accordance with the method described above. silver:

Storing the first section; And

Subsequently downloading sections that are transmitted immediately after the first section until the last section has been downloaded or a predetermined number of sections are stored, each section being stored sequentially in each memory location. .

In a fourth aspect, the present invention provides a method for storing a group of sections, periodically transmitted in the data stream, in accordance with the method, comprising a first section and a last section, the method comprising:

Downloading the first section;

Sections stored in a memory location are then overwritten by subsequently downloaded sections until the last section is downloaded and subsequently sent immediately after the first section until the last section is downloaded or a certain number of sections are stored. Subsequently downloading the sections; And

Storing said last section in said memory, each section being successively stored in a respective memory location.

In a fifth aspect, the present invention provides a method of storing a group of sections, wherein sections are transmitted periodically in the data stream, each group comprising a first section and a last section, the method comprising:

Receiving a data stream;

Downloading the first section and storing it in memory; And

Successively downloading sections transmitted immediately after the first section until the last section is downloaded or a predetermined number of sections are stored in the memory, each section being contiguous at each memory location. Stored as.

In a sixth aspect, the present invention provides a method of storing a group of sections which are transmitted periodically within the data stream and comprising a first section and a last section, the method comprising:

Receiving a first section;

Downloading the first section;

Sections stored in a memory location are then overwritten by subsequently downloaded sections until the last section is downloaded and subsequently sent immediately after the first section until the last section is downloaded or a certain number of sections are stored. Subsequently downloading the sections; and

Storing said last section in said memory, each section being successively stored in a respective memory location.

According to the third to sixth aspects of the invention, only the sections required from a group of sections are stored in the memory of the receiver / decoder. For example, when viewing a list of three television programs scheduled to be delivered at a particular time, the third and fifth aspects allow the end user to quickly scroll down the list starting from the first program shown then. Only the first four sections of the group are downloaded from the data stream. With the fourth and sixth aspects, only the last four sections of the group are downloaded from the data stream, allowing the end user to quickly scroll up the list starting from the last program shown then.

In a seventh aspect, the invention provides an apparatus for storing at least one section having at least one section characteristic among a plurality of sections of a transmitted data stream, the apparatus comprising:

Means for receiving a data stream;

Means for filtering the one section from the data stream according to the at least one section characteristic; And

Means for storing said one section.

Preferably, the filtering means is:

Means for specifying at least one filtering characteristic each including a filtering criterion and a value for the filtering criterion;

Comparing each one of the section characteristics with each filtering characteristic; And

Means for filtering the one section from the data stream when each one section characteristic matches each filtering characteristic.

In an eighth aspect, the present invention provides the above-described apparatus for downloading a plurality of said sections, said storage means comprising a plurality of memory locations for storing each section.

Preferably, the device is:

Means for specifying at least one data filtering characteristic each including a data filtering criterion and a value for the data filtering criterion;

Means for comparing each data filtering characteristic with data stored in each stored section; And

Means for enabling the stored section to be replaced in the memory when the data stored in the stored section does not match each data filtering characteristic.

The device also:

Means for supplying a section identification signal to an application when the data stored in the stored section matches the respective data filtering characteristic.

The method or apparatus may be used with the data stream in the form of an MPEG bitstream which also includes video and audio television data in addition to the sections.

The preferred features of the invention will now be described by way of example only with reference to the accompanying drawings.

1 shows an overview of a digital television system 1000. The present invention includes an almost common digital television system 2000 that uses a known MPEG-2 compression system for transmitting compressed digital signals. More specifically, the MPEG-2 compressor 2002 in the broadcast center receives a digital signal stream (typically a stream of video signals). Compressor 2002 is coupled to multiplexer and scrambler 2004 by linkage 2006. The multiplexer 2004 also receives a plurality of input signals, gathers one or more transport streams, transmits the compressed digital signals through the linkage 2010 to the transmitter 2008 of the broadcast center, and the linkage 2010 ) Can of course have a wide variety of forms, including telecom links. Transmitter 2008 transmits electromagnetic signals towards satellite transponder 2014 via uplink 2012, which are processed electronically in satellite transponder 2014 and then owned or leased by the end user. Typically broadcasted through the downlink to the terrestrial receiver 2018 in the form of a dish. The signals received by the receiver 2018 are transmitted to an integrated receiver / decoder 2020 that is owned or leased by the end user and coupled to the end user's television set 2022. Receiver / decoder 2020 decodes the compressed MPEG-2 signal into a television signal for television set 2022.

Conditional access system 3000 is coupled to multiplexer 2004 and receiver / decoder 2020, which is located partially in the broadcast center and decoder, respectively. This allows end users to access digital television broadcasts from one or more broadcasters. Smartcards may be inserted into the receiver / decoder 2020 capable of decrypting messages related to commercial applications (ie, one or several television programs sold by a broadcaster). Using the decoder 2020 and a smart card, the end user may purchase commercial applications in a reservation or pay per view mode.

The interactive system 4000, also coupled to the multiplexer 2004 and receiver / decoder 2020 and partially located in the broadcast center and decoder, respectively, allows the end user to interact with various applications via the modem back channel 4002. To do this.

2 shows the general structure of an interactive television system 4000 of a digital television system 1000 of the present invention.

For example, interactive system 4000 buys items from a catalog on the screen, requests local news and weather maps on demand, and enables games to be played through a television set.

The interactive system 4000 roughly has four main elements:

Authoring tool 4004 in a broadcast center (or elsewhere) for enabling broadcasters to create, develop, fix defects, and test applications;

MPEG-2 transport stream (typically its private section), coupled to authoring tool 4004, for broadcasters to prepare, verify, and format applications and data delivered to the multiplexer An application and data server 4006 in a broadcast center coupled to a scrambler 2004 for insertion into a;

Equipment within a receiver / decoder 2020 that is owned or leased by the end user so that the end user can receive, verify, decompress and load the application into the working memory 2024 of the receiver / decoder 2020 for execution. A virtual device including a time engine (RTE) 4008, which is executable executable code; And

Modem back channel 4002 between receiver / decoder 2020 and application and data server 4006 allowing server 4006 command signals to insert data and applications into the MPEG-2 transport stream upon end user's request. The engine 4008 also runs resident general purpose applications and is independent of hardware and operating systems.

Interactive television systems operate using an “application” that controls the receiver / decoder and the various devices contained therein. The applications are represented as “resource files” in engine 4008. A module is a set of resource files and data. You may need some modules to configure your application. The “memory capacity” of the receiver / decoder is the storage space for the module. The "interface" is used to download the module. The module may be downloaded from the MPEG-2 transport stream into the receiver / decoder.

Now, the elements described in the previous paragraph are described in more detail.

For purposes of explanation, the application is preferably part of computer code for controlling the high level functions of the receiver / decoder 2020. For example, when the end user presses the OK key with the remote control's focus on the button object shown on the screen of the television set 2022, the sequence of commands associated with the button is activated.

Interactive applications present menus, execute commands on demand from the end user, and provide data related to the purpose of the application. The applications may be resident applications, i.e., applications stored in ROM (or FLASH or other nonvolatile memory) of receiver / decoder 2020, or applications broadcast or downloaded into RAM or FLASH memory of receiver / decoder 2020. have.

Examples of applications are as follows:

Initialization application. Receiver / decoder 2020 has a resident initialization application, which is a set of modifiable modules that can be made to operate receiver / decoder 2020 immediately in an MPEG-2 environment (this item is defined in more detail below). do. The application provides core characteristics that can be changed by the broadcaster if necessary. It also provides an interface between resident and downloaded applications.

Startup application. The startup application allows all downloaded or resident applications to run on receiver / decoder 2020. This application acts like a bootstrap that runs on arrival of a service to start the application. The startup application can be downloaded into RAM and thus easily updated. It can be configured so that interactive applications available on each channel can be selected and run immediately after being downloaded or preloaded. When preloaded, the application is loaded into memory 2024 and activated by the startup circuitry if necessary.

Program guide. The program guide is an interactive application that gives complete information about programming. For example, it may give information about a television program provided on each channel of a digital television boutique, such as a week. By pressing a key on the remote controller 2026, the end user accesses an accessory screen that overlays the event shown on the screen of the television set 2022. This subscreen is a browser that provides information about the current and next events of each channel of the digital TV's bucket. By pressing another key on the remote controller 2026, the end user accesses an application that outputs a list of information about events for more than a week. End users also search for events and classify them by sample and ordered criteria.

Paid viewing application. The pay-per-view application is an interactive service that can be used on each PPV channel of the digital TV bucket with the conditional access system 3000. End users can access the application using a TV guide or channel browser. In addition, the application is automatically started as soon as a PPV event is detected on the PPV channel. The end user can then buy the current event through his daughter smart card 3020 or by the communication server 3022 (using a modem, telephone and DTMF code, MINITEL, etc.). The application resides in ROM of the receiver / decoder 2020 or is downloadable in RAM of the decoder 2020.

PC download application. Upon request, the end user can download the computer software using a PC download application.

Magazine browser application. The magazine browser application includes periodic video broadcasting of images by end user navigation by on-screen buttons.

Quiz application. The quiz application is preferably motivated with the quiz program being broadcast. For example, multiple selection questions are displayed on the screen of the television 2022 and the user can select the answer using the remote controller 2026. The quiz application can inform the user whether the answer is correct or not, and can continue to count the user's score.

Teleshopping application. In one example of a teleshopping application, an application for a merchandise for sale is delivered to a receiver / decoder 2020 and displayed over a television 2022. Using the remote control, the user can select a particular item to buy. Applications and data over the modem back channel 4002 with an order to debit an invoice for a credit card inserted into one of the card readers 4036 of the receiver / decoder 2020 as far as possible. The server 4006 or telephone number is sent to a separate sales system that is downloaded to the receiver / decoder.

Telebanking Application. In one example of a telebanking application, a user inserts a bank card into one of the card readers 4036 of the receiver / decoder 2020. When the receiver / decoder 2020 dials up the user's bank using a bank card or a telephone number stored on the receiver / decoder, the application can be selected using the remote controller 2026, for example by a telephone line. It provides a number of conveniences, such as downloading bills, requesting checkbooks, and transferring funds between accounts.

Internet browser application. In one example of an internet browser, commands from a user, such as a request to view a web page with a particular URL, are input using remote controller 2026, which is accessed by the modem back channel 4002 by an application and data server. Is sent to 4006. This would include the appropriate web page within the transmission from the broadcast center received by the receiver / decoder 2020 via uplink 2012, transponder 2014 and downlink 2016, to television 2022. Is displayed.

The applications are stored at a memory location within the receiver / decoder 2020 and represented as a resource file. Resource files include graphic object description unit files, variable block unit files, command sequence files, application files, and data files.

The graphical object description unit file describes the application's screen, human-machine interface. The variable block unit file describes the data structure processed by the application. The command sequence file describes the processing operation of the application. The application file provides the entry number for the application.

Applications configured in this manner can use data files such as, for example, icon library files, image files, character font files, color table files, and ASCII text files. Interactive applications can also obtain online data by generating input and / or output.

Engine 4008 loads only the resource files needed at a given time into its memory. These resource files are read from the graphic object description unit file, the command sequence file, and the application file; Variable block unit files are stored in memory, calling the procedure to load the module and remain locked until a specific call to the procedure to unload the module is made.

3, a module 4010, such as a teleshopping module, is a set of resource files and the data is:

Single application file 4012;

Indeterminate graphic object description unit file 4014;

Indeterminate variable block unit file 4016;

Indeterminate instruction sequence file 4018; And

Where appropriate, data files 4020 such as icon library files, image files, character font files, color table files, and ASCII test files are included.

In an MPEG data stream, each module composes a group of MPEG tables. Each MPEG table may be formatted as multiple sections. In an MPEG data stream, each section has a 4 kbyte "size". For data transmission by serial and parallel ports, for example, the module is similarly distributed into tables and sections, the size of the section varies with the transmission medium.

The module is transmitted in the MPEG data stream, typically in the form of a data package of 188 bytes, in separate types of data streams such as, for example, video data streams, audio data streams and teletext data streams. Each packet has a 13-bit packet identifier (PID) priority, and there is one PID for every packet transmitted in the MPEG data stream. The program map table (PMT table) contains a list of separate data streams and defines the contents of each data stream according to each PID. The PID alerts the device of the presence of applications in the data stream, and the PID is identified using the PMT table.

4, each section 4300 typically has the following fields:

At the beginning of section 4300, table ID (TID) 4302, typically having a one byte size;

A section length identifier 4304, typically having a size of 2 bytes;

Section number (SN) 4306 (eg, 1) of the section in the table, typically having a size of 1 byte;

The total number of sections (LSN) 4308 (eg, 3) in the table, typically having a size of 1 byte;

A TID extension 4310, typically having a size of 2 bytes;

Private data 4312; And

The CRC 4314 of the section 4300. The purpose of CRC 4314 is to check all bytes in section 4300; If the CRC 4314 correlates with all preceding data, the section is received by the receiver / decoder 2020. Similarly, personal datafield 4312 may include an MD5 signature at the end of the field and calculated from all previous contents of field 4312.

For data received by a serial or parallel interface, the fields of the section may change; Typically the section received by any of the previously mentioned interfaces includes a reduced amount of data in fields 4302-4310 and does not include CRC 4314.

For a particular module / table, all the sections that form the table have the same TID 4302 and the same TID extension 4310. For a particular application, all tables are configured so that the applications have the same TID, but each has a different TID extension.

For example, to access module 4010 from an MPEG bitstream, PIDs for modules and module directories are needed. This directory only writes the module 4010 which can be downloaded from the carrier signal. Once the directory is downloaded, it is possible for the application to download one or more modules 4010.

The concept of module 4010 along with the concept of downloading a small portion of code allows for easy deployment of applications. These can be downloaded into permanent FLASH memory of receiver / decoder 2020 as resident software or broadcast to be downloaded into RAM of decoder 2020 when needed by the end user.

The memory capacity is the storage space for the module 4010. This storage space is located in the memory 2024 of the receiver / decoder 2020. Referring to FIG. 5, memory 2024 may typically be divided into RAM capacity 4022, FLASH capacity 4024, and ROM capacity 4026. The memory also stores memory capacities associated with the various interfaces into which the module is downloaded into the receiver / decoder 2020, for example MPEG capacities for storing modules downloaded from the MPEG bitstream, and modules received by the serial interface. It can also be divided into series capacity to.

RAM capacity 4022 is in turn divided into a firmware dedicated zone, a workspace for the engine 4008, and a buffer. FLASH and other nonvolatile memory can be accessed by the engine itself through an application or device manager.

Each capacity includes a list of modules 4010, and each module 4010 includes a list of files 4012, 4014, 4016, 4018, 4020. It is possible to have two files with the same name and which may be located in separate modules. For example, a version of an application is typically stored in ROM capacity 4026 along with a later version that can be loaded into FLASH capacity 4024 to replace the version stored in ROM capacity with the capacity stored in FLASH capacity 4024. . The contents of the files may be compressed in the LZW format and may be received in the uncompressed format, although the decompression of the files may take some time.

The physical interface of the receiver / decoder 2020 is used to download the data. Referring to FIG. 6, receiver / decoder 2020 may include, for example, six downloading media; MPEG flow tuner 4028, serial interface 4030, parallel interface 4032, modem 4034, and two card readers 4036.

With multiple sources of applications and multiple manufacturing sources of receivers / decoders 2020, one application runs in the same way for all receivers / decoders, and each receiver / decoder runs all applications in the same exact manner. It is important to do it. Referring to FIG. 7, receiver / decoder 2020 includes a run time engine 4008 and a common application programming interface 4054 running under the control of a microprocessor. These are installed in all receivers / decoders so that all receivers / decoders 2020 can be identical from an application point of view.

7 shows the structure of a receiver / decoder 2020 for running applications 4056. The virtual device 4007 may include applications 4056 'that are directly coupled to the virtual device, or applications 4056 "that may be downloaded, for example, from the MPEG data stream to the receiver / decoder 2020. The runtime engine 4008 also displays graphics and text, invokes the device for service, receives “events” and utilizes the functionality of the library 4058 for specific calculations.

Referring to FIG. 7, the functionality of the decoder 2020 for the application is “shown” as the device 4060. Thus, it may be a function of the receiver / decoder 2020 that may not be seen by all applications.

Device 4060 includes a logic device unit that may match component 4082 or physical interface 4064 of hardware 4066. Such devices are referred to as “low level devices” 4068. The device 4068 may be coupled to at least one device driver 4070 to convert logic signals output by the device 4068 into signals required by the hardware interface 4064, for example. As a variant, the device 4068 may drive the components or interfaces of the receiver / decoder 2020 by itself. That is, the output of the device may be directly connected to the hardware 4066.

Examples of low level devices 4068 are described below.

The LCARD device allows a program to communicate with a smart card included in one smart card reader 4036, and the RCARD device enables the program to communicate with a smart card included in another smart card reader 4036. For example, these devices allow a program to read the status of a card, read the card history, and send input messages to the card. These devices also inform the program of the insertion of the card into the reader, removal of the card from the reader, and card reset if not requested by the program. LCARD and RCARD devices are specific to the protocol used to operate the card. Typically, ISO7816 protocol is used.

The SCTV device allows the program to verify and organize the scart oulet on the television set 2022. For example, the device allows you to request information about the sound characteristics of a scarlet outlet, perform “MUTE” on the sound, and dynamically program RGB levels.

The TUNER device allows the program to use the tuner 4028. For example, the device allows a program to perform a scan from the tuner's minimum or current frequency, read tuner parameters, and program the tuner.

SERIAL devices allow programs to communicate with devices by serial links, and PARALLEL devices allow programs to communicate with devices by parallel links.

The MODEM device allows the receiver decoder to communicate with the data service by internal half duplex modem support (V23). The MODEM device requires dialing of the number, sending a message to the data server and disconnection of the modem, signaling the reception of the message, the detection of errors and losses, or the detection of the carrier.

The remote devices running at the remote location can be any local device except that the port and protocol must be defined.

In addition to "low level devices", receiver / decoder 2020 may also include "high level devices" that control the operation of receiver / decoder 2020.

For sections loaded from an MPEG data stream, the device 4042, referred to as the “MLOAD device,” allows an application to load MPEG sections, complete MPEG tables or a group of MPEG sections corresponding to hardware and software filtering criteria. do.

Referring to FIG. 8, electromagnetic signals are received by the receiver 2018 and transmitted to the MPEG tuner 4028. The tuner typically scans a certain frequency range and stops only when a carrier frequency is detected within that range. Accordingly, the detected signals are transmitted to the demodulator 4500, and the demodulator demodulates the signals and then transmits the demodulated signals to the demultiplexer 4502. The demultiplexer 4502 is connected to an MPEG chip 4504 connected to the television 2022. Demultiplexer 4502 is also coupled to hardware filter 4506, which typically provides up to 32 outputs coupled to RAM capacity 4022 of receiver / decoder 2020.

The electromagnetic signals received by the demultiplexer 4502 are typically a data stream of data packets, including a stream of video packets, a stream of audio packets, a stream of teletext packets, and a stream of subtitle packets for services provided by the broadcaster. Include the number of. These data packets are demultiplexed by a demultiplexer 4502 and then sent to the MPEG chip 4504 to decode into a signal for the television set 2022.

Data packets related to the applications are sent to the hardware filter 4506. Referring to FIG. 9, a hardware filter, or prefilter 4506, typically includes an offset byte 0 4510 and an offset byte 3 to 9 4512 to filter sections from the data stream. Use one or more typical 8 bytes of These bytes include TID 4302, section number 4306, last section number 4308, and TID extension 4310 of MPEG section 4508.

To define the hardware prefilter characteristics, the application specifies the bits of section 4508 that are considered and the expected value of each select bit. Thus, the hardware prefilter 4506 includes a filter mask array 4514 and a filter value array 4516, respectively, an example of which is shown in FIG. In FIG. 10, bits 4518, 4520, 4522 are selected using filter mask array 4514, and the values of each of these bits 0, 1, 0 are selected using filter value array 4516, respectively. With these filtering criteria, the MPEG section 4524 will be output to the buffer of the RAM 4022 of the receiver / decoder 2020, while the MPEG section 4526 will not be output to the buffer.

The hardware prefilter 4506 is operated by the demultiplexer chip without wasting processor power in the main processor.

The microprocessor may utilize the RAM 4022 of the receiver / decoder 2020 in which the sections are stored as the software filter 4526. By using software filter 4526, it becomes possible to select which of the sections loaded into the buffer of RAM capacity 4022 will be brought into the application.

The principle of software filtering is similar to that of hardware filtering. Software filter 4526 typically uses eight consecutive data bytes 4528 in MPEG section 4508. As shown in FIG. 11, the position of the first byte 4530 of these eight consecutive bytes is defined with an offset 4532 based on the first byte 4510 in section 4508.

After loading by the hardware filter, if the data stored in the MPEG section does not match the criteria for software filtering, the buffer in which the MPEG section is stored may be used to load another MPEG section.

In order to load an MPEG section from an MPEG data stream, the MLOAD device typically has the following information:

PID of data stream in which MPEG section is found;

A descrambling data array comprising a plurality of PED ECMs for descrambling PIDs;

Operator criteria for recognizing a particular ECM used to descramble the PID;

An array of hardware filter values to be applied;

A hardware filter mask array to be applied;

Software filter offset value to be applied;

An array of software filter values to be applied;

A software filter mask array to be applied;

The maximum size of the section (up to 4096 bytes); And

A timeout function is provided that determines how long the device should wait to load a section, a group of sections or a table.

When the maximum size of a section is indicated as 512 bytes, the size of the section cannot exceed 512 bytes.

The sections are loaded all at once into a buffer of RAM capacity 4022 allocated by the device. When a section is loaded and if it matches the software filter criteria, the device must remove the demultiplexing route and notify the application through an "event" that contains the execution report and the address of the buffer containing the section. After loading, the section is identified by the address of the buffer where the section is stored.

When the table is loaded, the device is also supplied with a TID 4302. Each section of the table is loaded into each buffer, which is allocated all at once for this. However, the table does not have to be loaded with sections end to end and in order. As each section of the table is loaded, the device informs the application that the section of the table has been loaded. As a variant or in addition, the device notifies the application via the event that the entire table has been successfully loaded into the buffer allocated for it.

Referring to Figure 12, the table is typically loaded in the following way (the description of software filtering is omitted for reasons of brevity only):

Step 1: Specify a hardware filter mask array 4534 and a hardware filter value array 4452.

Step 2: Load the first section 4538 corresponding to the hardware (and soft) filter.

Step 3: Read the value of the LSN 4540 of the section 4538 to determine the number of loaded sections (= LSN + 1) and the hardware filter mast array 4534 and the hardware filter value according to the value of the LSN 4540. Replace array 4538.

Step 4: Load remaining sections 4452, 4544, and 4546 according to the value of TID and LSN and send an event to the application.

Table loading is complete only when an event indicating successful downloading enters the queue of runtime engine 4006. Before such an event is placed on the engine queue, the abortion of the table loading must be successful.

After the table is loaded, the name assigned to it by the table is checked when requesting a download of the table.

Information about how the table is stored in the memory of the receiver / decoder 2020 can be accessed by a call that returns a descriptor of the table. An example of such a descriptor is shown in FIG. 17. Descriptor 4700 includes a field 4702 that includes a total number of sections (LSN + 1) and a list of buffers 4704 in the table, the list of buffers 4704 having a section 4500 having an SN of "0". ) Sections 4546 with a SN of “1” followed by sections 4546, 4542, 4544 and 4546 that form a table starting with section 4452 with SN corresponding to LSN. Include.

Sections of a group include all sections that match hardware and software filtering criteria. Sections appear periodically in the MPEG data stream.

Referring to FIG. 13, group 4548 includes two sections; It is delimited by the first section (SDG) 4550 and the last section (SFG) 4452, each of which corresponds to individual filter criteria with the other sections (SG) 4454 in the group between them.

Loading of sections in a group may occur using two different loading modes.

In the "following mode", a predetermined number of sections 4454 immediately following the SDG 4550 is loaded. For each type of section (SDG, SG, SFG), the application checks the TID, hardware filter, software filter and maximum section length.

Referring to FIG. 14, the device preferably applies hardware and software filtering criteria first so that only SDG 4550 can be downloaded and stored. This prevents extra SGs 4454 from being loaded into the buffer of the RAM memory capacity 4022 of the receiver / decoder 2020 before loading the SDG 4550. Upon detection, SDG 4550 is stored in a memory location or buffer 4556. The device then applies hardware and software filtering criteria to load desired SGs and SFGs from a group of MPEG data sections.

In FIG. 14, three SGs 4454 can be downloaded from an MPEG data stream from a group of MPEG sections containing one SDG, seven SGs, and one SFG. After the SDG 4550 is stored in the buffer 4556, the first SG 4558 from a group of MPEG sections transmitted after the SDG 4550 is stored in the buffer 4560. Similarly, a second SG 4652 from a group of MPEG sections transmitted after SDG 4550 is stored in buffer 4564 and three from a group of MPEG sections transmitted after SDG 4550. The first SG 4566 is stored in the buffer 4568.

Storage of the SGs continues until the required number of sections 4454 are stored or SFG 4452 is downloaded. If downloaded, SFG 4452 is not stored in the memory location.

When each section of the group is loaded, the device notifies the application that the section of the group has been loaded via an event. As a variant, or in addition, the device may inform the application of the completion of the storage of MPEG sections, or only the downloading of SFG 4452 by sending an event to the application.

In the "preceding mode", a predetermined number of sections immediately preceding the SFG are stored in the memory location. For each type of section (SDG, SG, SFG), the application checks the PID, TID, hardware filter, software filter, and maximum section length.

Loading in this mode requires the use of a circular buffer to store MPEG sections.

Referring to FIG. 15, the device preferably applies hardware and software filtering criteria first so that only SDG 4570 can be downloaded and stored. This prevents loading of extra SGs 4544 of RAM memory capacity 4022 of the receiver / decoder 2020 before loading the SDG 4570. As soon as detected, the SDG 4550 is not stored. The device then applies hardware and software filtering criteria to be able to download the desired SGs and SFGs from the MPEG data sections.

In the example shown in FIG. 15, three SGs 4544 can be downloaded from an MPEG data stream from a group of MPEG sections containing one SDG, seven SGs, and one SFG. Following the downloading of the SDG 4570, the first SG 4652 from a group of MPEG sections transmitted after the SDG 4570 is stored in the buffer 4474. Similarly, a second SG 4576 from a group of MPEG sections transmitted after SDG 4550 is stored in buffer 4578 and three from a group of MPEG sections transmitted after SDG 4570. The first SG 4580 is stored in the buffer 4458.

The fourth SG 4584 from a group of MPEG sections transmitted after the SDG 4550 is stored in the buffer 4646, ie the buffer in which the first SG 4652 is stored. Similarly, each SGs 4586, 4588, and 4590 that are subsequently transmitted are stored in buffers 4578, 4582, and 4574, respectively.

Storage of SGs by this cyclical method continues until the SFG 4652 is detected by the device. This is true even if the desired number of SGs is not loaded before SFG is detected. As soon as detected, SFG 4652 is stored in a buffer and an event is sent to the application indicating successful downloading of the group.

Information about how the group is stored in RAM 4022 of the receiver / decoder 2020 can be accessed by a particular call that returns the group's descriptor. An example of such a descriptor is shown in FIG. 16. Descriptor 4600 includes a field 4602 and a buffer list 4604 that includes the number of sections in the group, where the buffer list 4604 forms the SDG or SFG (depending on the loading mode) and the group in loading order. Sections SG.

After a group is loaded, the name assigned to it by the application is uniquely identified when requesting a download of the group.

It is possible to add sections to or remove sections from a group. A section may belong to one or more groups.

When an application requires the addition of a section to a group, the address of the buffer containing the new section is put at the end of the descriptor 4604, and the field 4602 is updated. When an application requests the deletion of a section from a group, the address of the buffer that contains this section is deleted in descriptor 4600 and field 4602 is updated. If the section is not the last section in the group, the descriptor reconstructs to delete all free memory spaces. Thus, it is possible to have an "empty group" by deleting all sections.

The devices are identified with a unique identifier, for example “LCARD_DEVICE_ID” which identifies the LCARD and “RCARD_DEVICE_ID” which identifies the RCARD device.

When a new device 4062 is created, it can be installed in the existing decoder 2020 by downloading the appropriate application 4056 from the broadcast center. Typically, the maximum number of devices handled by one manager is 256.

This downloading is performed at the receiver / decoder 2020 by the application 4056, which checks the hardware and software version, and if yes, loads a software module representing the new device 4082, The procedure of toolbox 4058 is required to install device code in firmware (in FLASH memory). This makes it possible to flexibly and securely install new functions within the decoder 2020 without stopping the software.

The invention has been described above by way of example only, and it is obvious that changes in details may be made within the scope of the invention.

Each feature, (appropriate) claim and drawing described in the detailed description may be provided independently or in any suitable combination.

In the preferred embodiment described above, certain aspects of the invention have been implemented using computer software. However, it will be apparent to one skilled in the art that all these features can be implemented by hardware. In addition, it will be readily understood that hardware, computer software, and the functions performed by these may be performed on or with electricity and such signals.

Signal generation and broadcasting (agent reference number PC / ASB / 19707), smart cards for use with receivers of encrypted broadcast signals (agent reference number PC / ASB / 19708), broadcast and reception systems, and conditional access systems therefor (Attorney Ref. No. PC / ASB / 19710), Downloading computer files from the transmitter to the computer using a receiver / decoder (Attorney Ref. No. PC / ASB / 19711), Transmitting and receiving television programs and other data (Attorney Reference) PC / ASB / 19712), downloading data (agent reference number PC / ASB / 19713), computer memory configuration (agent reference number PC / ASB / 19714), television or radio control system development (agent reference number PC / ASB / 19715), extraction of data sections from the transmitted data stream (agent reference number PC / ASB / 19716), access control system (agent reference number PC / ASB / 19717), data processing system (agent reference number) PC / ASB / 19718), and our concurrently pending applications entitled Broadcasting and Receiving Systems, Receivers / Decoders and Remote Controllers for them (agent PC / ASB / 19720), all having the same filing date. The literature crosses. The contents of these documents are incorporated herein by reference. The list of applications includes the present invention.

Claims (19)

A method for storing at least one section having at least one section characteristic among a plurality of sections of a transmitted data stream, the method comprising: Receiving a data stream; Filtering the one section from the data stream according to the at least one section characteristic; And Storing the one section. The method of claim 1, wherein the filtering step: Specifying at least one filtering characteristic each including a filtering criterion and a value for the filtering criterion; Comparing each section characteristic with each filtering characteristic; And Filtering the one section from the data stream when each section characteristic matches each filtering characteristic. 3. A method according to claim 1 or 2, wherein each section is stored in a respective memory location. The method of claim 3, wherein the method is Designating at least one data filtering characteristic each including a data filtering criterion and a value for the data filtering criterion; Comparing each data filtering characteristic with data stored in each stored section; And When the data stored in the stored section does not match the respective data filtering characteristic, allowing the stored section to be replaced in the memory. 5. The method of claim 4, further comprising supplying a section identification signal when the data stored in the stored section matches the respective data filtering characteristic. 6. The method of claim 5, wherein the section identification signal comprises a storage address of the one section. The method according to any one of claims 3 to 6, A method of storing a group of sections transmitted periodically within the data stream and comprising a first section and a last section: Storing the first section; And Subsequently downloading sections that are transmitted immediately after the first section until the last section has been downloaded or a predetermined number of sections are stored, each section being successively stored in a respective memory location. Characterized in that the method. The method according to any one of claims 3 to 6, A method of storing a group of sections transmitted periodically within the data stream and comprising a first section and a last section, Downloading the first section; Sections stored in a memory location are subsequently overwritten by the next downloaded sections until the last section is downloaded and subsequently sent immediately after the first section until the last section is downloaded or a certain number of sections are stored. Subsequently downloading the sections; And Storing the last section in the memory, wherein each section is successively stored in a respective memory location. A method of storing a group of sections that is transmitted periodically within a data stream and includes a first section and a last section, Receiving a data stream; Downloading the first section and storing it in memory; And Successively downloading sections transmitted immediately after the first section until the last section is downloaded or a predetermined number of sections are stored in the memory, each section being contiguous at each memory location. Method is characterized in that it is stored as. A method of storing a group of sections that is transmitted periodically within a data stream and includes a first section and a last section, Receiving a first section; Downloading the first section initially; Sections stored in a memory location are then overwritten by subsequently downloaded sections until the last section is downloaded and subsequently sent immediately after the first section until the last section is downloaded or a certain number of sections are stored. Subsequently downloading the sections; and Storing the last section in the memory, wherein each section is successively stored in a respective memory location. A method of storing at least one of a plurality of sections of a substantially transmitted data stream described herein in connection with the appended drawings. An apparatus for storing at least one section having a section characteristic of at least one of a plurality of sections of a transmitted data stream, the apparatus comprising: Means for receiving a data stream; Means for filtering the one section from the data stream according to the at least one section characteristic; And Means for storing said one section. The method of claim 12, wherein the filtering means is: Means for specifying at least one filtering characteristic each including a filtering criterion and a value for the filtering criterion; Comparing each one of the section characteristics with each filtering characteristic; And Means for filtering the one section from the data stream when each one section characteristic matches the respective filtering characteristic. 14. A method as claimed in claim 12 for downloading a plurality of said sections, And said storage means comprises a plurality of memory locations for storing respective sections. The method of claim 14, Means for specifying at least one data filtering characteristic each including a data filtering criterion and a value for the data filtering criterion; Means for comparing each data filtering characteristic with data stored in each stored section; And Means for enabling said stored section to be replaced in said memory when data stored in said stored section does not match said respective data filtering characteristic. 16. The apparatus of claim 15, further comprising means for supplying a section identification signal to an application when the data stored in the stored section matches the respective data filtering characteristic. 17. The apparatus of claim 16, wherein the section identification signal comprises a storage address of the one section. A method or apparatus according to any preceding claim for use in said data stream in the form of an MPEG bitstream comprising video and audio television data in addition to said sections. An apparatus for storing at least one of a plurality of sections of a substantially transmitted data data stream described herein in connection with the appended drawings.