WO2005109867A1

WO2005109867A1 - A method for retrieving service information data

Info

Publication number: WO2005109867A1
Application number: PCT/CN2005/000623
Authority: WO
Inventors: Hongtao Liao; Xun Liu; Haisheng Sun
Original assignee: St Microelectronics Nv
Priority date: 2004-05-09
Filing date: 2005-05-08
Publication date: 2005-11-17
Also published as: CN1571502A; CN100438608C

Abstract

This invention discloses a method for retrieving service information data. The service information data is used for storing and managing the network information, transport stream information and service information applied for digital television application; and it can be conveniently added or extracted via application interface. All the data in database is stored in the form of tables, which comprise device context table, network table, transport stream table, service information table, channel number table, string table and private data table. All the tables are related to ID and key. The method use the direct index strategy, so it can retrieve or locate data in tables quickly and conveniently. It has advantage in speed in comparing with storing the data in the form of list and also resolves the problem that it can not define variable length data blocks in the case of storing the data in the form of array.

Description

Method for retrieving business information data

The invention relates to a database access method for retrieving service information, and belongs to the technical field of digital television reception. Background technique

Digital TV receiving equipment refers to hardware equipment that can receive, decode, and display digital TV signals. It is used in the field of digital TV and is a terminal for the realization of digitalization of analog TV (see Figure 1). Digital television receiving equipment receives digital image and data information. Therefore, unlike traditional analog television signal receiving and processing, digital television receiving equipment receives and processes digital image information and data through its internal CPU. And peripheral devices connected to it. The receiving system is based on the corresponding hardware and operating system to develop applications suitable for digital television receiving equipment; Similarly, some professional digital broadcast content service providers also need to develop according to the hardware performance and functions of different digital television receiving equipment Corresponding service software.

In a broadcasting station of a television station or a television operator, audio and video signals and data content are mixed through a front-end multiplexer to form a transport stream (TS stream). The transmission stream is modulated to form an electromagnetic signal and transmitted to a digital television receiving device. The working principle of digital TV receiving equipment (set-top box) is as follows:

♦ The tuning / selection module receives electromagnetic signals and selects a certain range of bandwidth.

♦ The demodulation module converts signals into data streams (Bitstreams).

♦ The demultiplexing module extracts the desired information from the data streams (Bitstreams) and provides it to different decoders in a suitable way. It includes a descrambler that cooperates with the conditional access module.

♦ The video decoding module converts the video bit stream in the displayed image sequence.

♦ The audio decoding module converts the audio bit stream in the analog audio signal.

♦ The graphics engine builds the graphics layer and mixes it with the video in the PAL / NTSC analog signal request before sending.

♦ The front control panel is responsible for interpreting user commands issued by the remote control, wireless keyboard or front panel. The video bit stream and audio bit stream are mixed with the image through the image processor, and become analog audio and video signals, which are output to the display screen (TV). The data stream flows into the CPU through the demultiplexer and is processed by the system program running on the central processing unit (CPU). The processed results can be mixed with the audio and video streams and output to the display device.

A network corresponds to multiple transport streams, and a transport stream corresponds to multiple services. Each network, each transport stream, and each service industry corresponds to an identifier ( ID). When transmitting in the network, these information are divided into tables of different formats and encapsulated in TS (Transport stream) packets, each of which has a complete structure. After the receiving device receives the TS packet, the original fragment is decomposed by the demultiplexer (Demux) to form tabular data. These information tables are broadcast in the network at certain time intervals. The content of the broadcast may change with time, which is determined by the data broadcasting system.

In the existing digital television receiving equipment technology, generally there is no well-defined technology for receiving, storing, and analyzing these service information data. In some digital television receiving equipment, these data are not stored, so that each time a digital television user switches channels, the data is loaded immediately, and the necessary information is also parsed and extracted, so it takes time and the user is in a waiting state. , Affects the viewing effect. In other receiving devices, even by the storage method, the network, the transport stream, and the service structure are separately established, and an array or a linked list is used to sequentially search through their identifiers. The disadvantages of these two methods are: the array method cannot define data blocks of indefinite size, and the linked list method increases the overhead of allocating and freeing memory. At the same time, both methods are slow in searching and relatively inefficient. In a hardware environment where digital television receiving equipment resources are relatively scarce, it is particularly undesirable.

The method of the present invention is a solution proposed for the deficiency of traditional technology. Summary of the invention

The technical problem to be solved by the present invention is to provide a method for efficiently retrieving business information data. The advantage of this method is that by establishing a service information database (SI Datebase) in a digital television receiving device (or set-top box) for storing and Manage digital television service information (SI), specifically network information (Network), transport stream information (Transport Stream), and service information (Service), so as to achieve the purpose of efficiently retrieving business information data.

The present invention solves the above problems through the following technical solutions. In the digital television receiving device, a service information storage is set, and when the set-top box is started, the required network information, transport stream information, and service information are retrieved by scanning the set-top box, and stored in the form of a database table structure . In the database table structure involved in the present invention, a type of related data may be stored in a certain memory area with a certain or non-deterministic structure. A piece of data has its own length and other information, and an index is stored to determine the position of the next piece of data. Compared with the commonly used storage methods of arrays or linked lists, this method saves memory space to the greatest extent, and makes up for the shortcomings of the other two methods, even in systems where the memory is not very large. At the same time, based on this storage structure, a data block with a specified number is retrieved by starting from the header of a table, determining the position of the next block according to the length information and position of each block, and comparing the block numbers to finally find the desired data block Thus, a highly efficient information retrieval function is realized.

The technical solution of the present invention is described in detail below.

Steps of the method:

1. Define the structure of the relevant tables of the business information database

The following tables are defined in the business information database structure: Tuning device table (DeviceContext table), network table (Network table), transport stream table (Transport Stream table), service information table (Service table "channel numbering table (Numbering table) The string table (String table) and private data table (Private data table) are associated with each other by an identifier (ID) and a key (Key).

In the following expressions, uint8, uintl6, and uint32 identify 1-byte, 2-byte, and 4-byte unsigned integers respectively; char [] represents a character string. The storage structure of each table is as follows:

Tuning equipment table:

The length of each unit of the tuning equipment table is 3 bytes, and the storage structure is as follows (the numbers represent the corresponding fields, the same below):

Number Domain Name Variable Type Domain Length (Bytes) Description

1 DeviceContextID uint8 1 Tuning device ID

2 Net orkID uintl6 2 Network ID

Netlist:

The length of each unit of the netlist is 12 bytes, and the storage structure is as follows (the numbers represent the corresponding fields, the same below)

4

Domain name Variable type Field length (bytes) Description

NetworkID uintl6 2 Network ID

Net orkNamelD uint32 4 Network name ID

PrivateDatalD uint32 4 Private data ID Transport stream table:

The length of each unit of the transport stream table is 29 bytes, and the storage structure is as follows:

Number Domain Name Variable Type Domain Length (Bytes) Description

1 DeviceContextKey uint32 4 Key of the tuning device of the network

2 TransportStreamID uintl6 2 Transport Stream ID

3 OriginalNetworkID uintl 6 2 Original network ID

4 TunningType uint8 1 Tuning type

5 Frequency uint32 4 BIS frequency

6 SymbolRate uint32 4 symbol rate

7 TuningCommonlnfo uint32 4 Tuning general information

8 TuningSpecificInfo uint32 4 Tuning specific information

9 PrivateDatalD uint32 4 Private data ID business information table:

The length of each unit of the service information table varies according to the number of elementary streams included in the service. The storage structure is as follows:

Among them, a Stream part is composed of information of multiple elementary streams, and the length of each elementary stream information is 8 bytes, and the actual length of the part is determined by SreamCount.

Number Domain Name Variable Type Domain Length (Bytes) Description

1 TransportStreamKey uint32 4 Key of the transport stream

2 ServiceNamelD uint32 4 String ID of the full name of the service

3 ShortServiceNamelD uint32 4 String ID of the short name of the service

4 ServicelD uintl6 2 Service ID 5 PmtPid uintl 6 2 Pid of Pmt table

6 CASystemID uintl 6 2 CA system ID

7 ECMVideoPid uintl 6 2 Pid of ECMVideo table

8 ECMAudioPid uintl 6 2 Pid of ECMAudio table

9 PCRPid uintl6 2 Pid of PCR table

10 Type uint8 1 Type of service

11 Flags uint8 1 Service identification

12 Properties uint8 1 Service properties

13 StreamCount uint32 4 ID of private data

14 —Stream

14. 1 Type uint8 1 elementary stream type

14. 2 ComponentTag uint8 1

14. 3 Pid uintl6 2 Elementary stream PID

14. 4 Language [3] int8 3 Basic stream language

14. 5 AudioType int8 1 The type of the audio channel number table. The length of each unit is Count * 6 + 4 bytes. The storage structure is as follows:

A group of ServiceKey and Properties represents a channel, with a total of Count, and the channel numbers are 1, 2, 3 ...

Domain name Variable type Domain length (bytes) Description

NumberingID uintl6 2 Numbering ID Count uint32 2 Number of channels

ServiceKey uint32 4 Key Properties for channel corresponding service uint32 2 Channel properties String table:

The length of each cell of the string table is variable, and the storage structure is as follows: 1 2 3 1 2 3 1 2 When looking up in the table, jump from one cell to the next cell according to the ID and length, up to the specified string cell.

Number Domain Name Variable Type Field Length (Bytes) Description

1 StringID uint32 4 ID of the string

2 Length uint8 1 Length of the string

3 String char [] string (ending with \ 0)

Proprietary data sheet:

The length of each unit of the proprietary data table is indefinite, and the storage structure is as follows:

Size represents the total length from a unit;

A set of Tag, Length, and Data represents a descriptor with a total of Count descriptors. Number Domain Name Domain Length (Bytes) Description

1 PrivateDatalD uint32 4 ID of private data

2 Size uint32 4 Total length of the private data unit

3 Count uint32 4 Number of descriptors

4 Tag uint8 1 Type of descriptor

5 Length uint8 1 Length of the descriptor

6 Data char [] Descriptor data

2. Establish the relationship between the index of the business information database and the information table

All data of the business information database are stored in the form of tables in permanent storage, such as flash memory (Flash), hard disk, etc., and are loaded into random storage when the receiving device starts. Each table is composed of different cells. Each cell has a different key. It is an index to find related information. It is a zero-based cell sequence number that is used to distinguish different cells. For fixed-length cells, you can directly locate them in the table by key value and cell length; for cells of indefinite length, you can also search by order of cell length information and key value stored in each cell.

The data in the business information database is related by the corresponding identifier value and key value of each table. Zone of both In addition, the value of the identifier is unique but not necessarily continuous, but the key values are continuous relative to the same table. This continuous feature makes it very convenient to find and locate data in the data table. The relationship between the tables is shown in Figure 2.

If there is related string information in the table, the fields of the string are the same as those in the string table by their ID numbers.

StringID (for example, ServiceNamelD in the business information table represents StringID in the string table); the proprietary data table is used to store some auxiliary and supplementary information. If a table has a private description identifier

(PrivateDatalD), which means that it is associated with a proprietary data table. '

If the network ID of the TV network is known, the corresponding network key can be obtained, and the related information of the network can be obtained from the network information table. Similarly, the information of the transport stream and the service can be obtained according to the network id, the transport stream id, or the service id.

The function of the channel label table is to show the relationship between channels and services. The structure of the channel number table is as shown above: Each number is represented by a NumberingID. Different digital TV operators can use different channel representations, and each representation is a number. On a numbered unit, a group of [service key, service properties] represents a channel. When searching, the given numbering id and channel number (that is, the location of [service key, service properties] in the numbering table) can uniquely determine the service corresponding to the channel.

The method of the present invention is further described below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a block diagram of the operation of digital television equipment. The digital TV signal enters the receiving device and is processed by the demodulation and demultiplexing module to separate the audio and video signals from the data signal. The event information data carried in the data signal is processed and stored for display on the TV screen.

Figure 2 is the association between several tables of the business information database. It identifies several information tables to establish a relationship through a key value (Key), and finds the corresponding information in turn through the corresponding key value and identification (ID). In the channel number table, there is a key value for finding a service information table; in the service information table, there is a key value for finding a transport stream information table; in a transport flow information table, there is a key value for finding a network information table. Relevant information can be obtained in each table by key value.

The present invention will be further described in detail below with reference to specific implementation examples.

detailed description

Embodiment 1: Filling of business information data. When the set-top box was started for the first time, the service information database was empty. At this time, the network information table, the service information table (the necessary information tables for digital TV are: PAT, PMT, NIT, SDT or BAT, etc.) are loaded to obtain the network information, transport stream information, service name, corresponding information of digital TV transmission According to the broadcast channel information of the audio and video streams and the like, a service information database is established according to the service information table defined by the method and the corresponding search relationship.

Embodiment 2: Retrieval of business information. It is assumed that necessary data is stored in the service information database, including a cable network, three transport streams in the network, and six sets of digital television programs, and these information are stored in a network information table, a transport stream table, and a service information table, respectively. The channel number table stores the channel information corresponding to the six sets of programs, and the six sets of digital programs are represented from 1 to 6, respectively.

Now, an application needs to switch from the current 4 channel to the 3 channel. It first needs to know which program is the 3 channel, which can be obtained from the channel number table, and includes the service key value Ser _V i _Ce Key of the corresponding channel. According to this, channel information can be obtained in the service information table, including the key value TransportStreamKey of the transport stream corresponding to the channel, and the corresponding transport stream information can also be obtained in the transport stream table through the TransportStreamKey. These information are used to switch channels. The most important thing is the frequency of the transport stream. Pass this frequency information to the hardware demodulator in the receiving device to switch to the transport stream where the program is. At this point, a channel switch is complete.

What should be explained in the end: The present invention provides a method for efficiently retrieving a business information database and its design concept. The above embodiments are only used to illustrate rather than limit the technical solutions of the present invention. After detailed description, those of ordinary skill in the art should understand that the present invention can still be modified or equivalently replaced without any modification or partial replacement that departs from the spirit and scope of the present invention, which should be covered by the claims among.

Claims

Rights request

1. A method for retrieving service information data, characterized in that, in a digital television receiving device, a service information database is established for storing and managing digital television service information, specifically network information, transport stream information, and service information, etc. information.

2. A method for retrieving business information data according to claim 1, characterized in that it realizes effective data retrieval by storing all data in a table form, and the main table structure includes:

A network information table that stores related network information;

Transport stream table, storing relevant transport stream information;

Business information table, storing related business information;

Channel number table, which stores information that can be numbered in sequence;

String table, storing string information;

Proprietary data tables that store network, transport stream or business related information.

3. A method for retrieving business information data according to claim 2, characterized in that it uses key values to associate different tables of the business information database, and the retrieval method is mainly performed by key values. In the channel number table, there is a key value for finding a service information table; in the service information table, there is a key value for finding a transport stream information table; in a transport flow information table, there is a key value for finding a network information table. Relevant information can be obtained in each table by key value.

4. The method for retrieving service information data according to claim 2, characterized in that it is performed by searching in different forms of the service information database and also by an identifier; in the network information table, there is transmission The stream information identifier is used to find the information of the transport stream. In the transport stream information table, there is a service information identifier to find the service information.

5. The method for retrieving service information data according to claim 2, characterized in that the channel number table, the character string table, and the proprietary data table involved in the method are tables of variable unit length, through which the variable can be realized Access to length data blocks.

6. The method for retrieving business information data according to claim 2, characterized in that it can also use other tables to store other information, and in these tables, specific data items can be added And deleted, but the search method remains the same.