CN101175204B - Method for searching electric program menu in digital television system - Google Patents

Abstract

The present invention discloses a method for searching an electronic program guide (EPG) in a digital television system, which includes two steps. Firstly, a program association table (PAT) is sought out from a multiplexed stream, and the program association table (PAT) is parsed in order to obtain the packet identifier (PID) of the program mapping table (PMT) of each service and the packet identifier (PID) of the network information table (NIT) of each service; secondly, according to the parsing result, all forms transmitted by the multiplexed stream are searched and filtered out. Without increasing the hardware cost, the present invention can accelerate the searching of the electronic program guide (EPG) and increase the searching efficiency.

Description

The method of searching electric program menu in a kind of digital television system

Technical field

The present invention relates to electric program menu (EPG, Electronic Program Guide) search technique, refer in particular to the method for search EPG in a kind of digital television system.

Background technology

Digitlization is a mondial new technology revolution, is the inexorable trend of radio and television development.In developed country and area; DTV has got into the large-scale commercial applications application stage at present; Especially nearly 2 years; DTV has begun the scale commercialization in a lot of cities, and as long as the user is at DTV STB of television set external connection, just can be accomplished the functions such as EPG search, channel selection, decoding, output of DTV by it.

Network layer is through each passage or transponder; Send module informations such as the video in each item business, audio frequency, data to STB through broadcast mode; Its transport model is as shown in Figure 1; STB receives these information and it is construed to the navigation information that both pictures and texts are excellent, helps the user in numerous digital television business, to carry out channel quickly and switches and program searching.Wherein, The circulation way of network layer can be a satellite transmission; Also can be wire relay broadcasting or overland propagation; And the information that these circulation ways are propagated is that multiplexing each passage of process together or transponder are propagated downwards, and multiplexing these information together are called multiplex stream, and the set of several business is called bouquet.

EPG information is with business information (SI; Service Information) form of form is multiplexing is transmitting stream (TS; Transport Stream) transmit in the code stream, STB needs to accomplish the EPG search earlier before use, extracts programme information and shows the user to select; In use, if programme information changes, STB also need carry out the EPG search again.Because multiplexing EPG amount of information in code stream is very big; The time of accomplishing once search needs is longer, and can't watch program EPG searching period user, for better experience impression is provided to the user; Need to adopt a kind of searching method fast, shortened search time as far as possible.

The EPG information search relates to Program Association Table (PAT; Program Association Table), Program Map Table (PMT; Program Map Table), network information table (NIT, Network InformationTable), BAT bouquet association table (BAT, Bouquet Association Table), SDT Service Description Table (SDT; Service Description Table), Event Information Table (EIT, Event Information Table) etc.Wherein, professional to each multiplexing road, PAT provides the position of corresponding Program Map Table (PMT); Be the value of the PID Packet Identifier (PID, Packet Identifier) of TS bag, the position of network information table (NIT) also is provided simultaneously; Here, TS also claims multiplex stream; The PMT sign has also been indicated the position of forming the professional stream in every road, and the position of every road business program clock reference (PCR) field.

Here, the position of NIT table meets GB/T 17975.1-2000 standard, but data format has exceeded the scope of GB/T 17975.1-2000, and this is for the information of more relevant physical network is provided; BAT provides bouquet relevant information, has provided the title of bouquet and the service lists in each bouquet; SDT has comprised the data of business, for example Business Name, service supplier etc. in the descriptive system; EIT has comprised the data relevant with incident or program, and for example incident title, zero-time, duration etc., different descriptors is used for the transmission of dissimilar event informations, for example different business types.The set of NIT, BAT, SDT, EIT, TDT, TOT etc. is called SI.

In the prior art, for routine processes is simple, the common search routine of EPG information is the transport model according to EPG, adopts PAT->PMT->NIT->BAT->SDT->the EIT mode of searching for successively.Be exactly specifically: when the multiplex stream transmission comes, the first step, search PAT obtains the PID of each PMT and the PID of NIT.Here, the PID of BAT, SDT, EIT is by ETSI EN 300 468 agreements regulation, and BAT PID and SDT PID are 0x0011, and the PID of EIT is 0x0012, and the PID of different table distinguishes through table identifier table_id; Second the step, search for each PMT, set up program number with the composition program source code flow (assembly) between mapping; In the 3rd step, search NIT sets up all multiplex stream information in the network; In the 4th step, search BAT sets up bouquet information; In the 5th step, search SDT sets up business information; In the 6th step, search EIT sets up program schedule information.Here, the search in the 4th step can be carried out, and also can not carry out, and promptly the 4th step was optional.All information that search just constitute complete EPG information, and showing is exactly the EPG that sees on TV.

In Moving Picture Experts Group-2, stipulate all Program Specific Information (PSI, Program SpecificInformation), must constantly send with certain frequency, per second must not be less than 20 times, and the transmission frequency is very fast, and here, PSI comprises PAT, PMT.In addition, digital television protocol requires shown in table one transmission intercal of SI table, and here, the SI table comprises NIT, BAT, SDT, EIT, TDT, TOT.

The SI table	Transmission intercal (second)
		All NIT segmentations	10
All BAT segmentations	10
		This stream SDT segmentation	2
Other stream SDT segmentation	10
		This stream is current/next EIT segmentation	2
All EIT segmentations in eight days	10
		All EIT segmentations after eight days	30

Table one

This shows that if do not consider promptly not consider PAT, PMT by PSI, and only transmit eight days EPG amount of information, the search routine of a complete EPG needs 40s at least.In the multiplex stream of reality, various tables are alternating in together and transmit, and do not have strict transmission order, and repeat to send.In addition, the amount of information that transmits downwards also can be the amount of information in other fates beyond eight days, and concrete amount of information is decided by operator as required.

If the multiplex stream sequence is illustrated in figure 2 as: PAT, NIT, PMT1, PMT2, BAT, SDT1, EIT1, SDT2, EIT2 ..., PAT, NIT, PMT1, PMT2, BAT, SDT1, EIT1, SDT2, EIT2 ....If adopt serial search mode as shown in Figure 3, search for PAT-successively>PMT->NIT->BAT->SDT->EIT, concrete way of search combines Fig. 2, Fig. 3; Search for PAT earlier, PAT finds, and searches for PMT again; If PMT does not find, but find NIT, then the NIT with the period 1 abandons; When PMT arrives, after processing PMT finishes, search for NIT again, because NIT abandons, then in second round, just can find NIT.Use the same method and search for NIT-successively BAT->SDT->EIT, visible, the time that this EPG serial search mode spends is longer, and search efficiency is lower.

Mainly use STB when searching for EPG in the prior art, tuner, filter, the full searcher of EPG and EPG data storage are arranged in the STB, wherein, tuner is mainly used in the multiplex stream that demodulates is transferred to filter; Filter is used for filtering out needed form from the form that multiplex stream sends; The full searcher of EPG is used for the form that Search Filter filters out, and the form that searches is resolved; The EPG data storage is used to store the information that parses through the full searcher of EPG.

The serial approach flow process of search EPG is as shown in Figure 4 in the concrete prior art, may further comprise the steps:

Tuner in step 401, the STB is provided with the search frequency to the dominant frequency point, demodulates the multiplex stream of dominant frequency point, and the multiplex stream that demodulates is transferred to filter;

Here, the multiplex stream of dominant frequency point includes all EPG information datas of whole network.

The full searcher of EPG in step 402, the STB is provided with PAT PID in filter;

Step 403, filter filter multiplex stream according to PAT PID, filter out PAT;

Step 404, the full searcher of EPG are searched for the PAT that filters out in filter;

Step 405, the full searcher of EPG are resolved PAT, obtain each professional PMT PID and NIT PID;

Step 406, the full searcher of EPG are provided with PMT PID in filter;

Step 407, filter filter multiplex stream according to PMT PID, filter out PMT;

Step 408, the full searcher of EPG are searched for the PMT that filters out in filter;

Step 409, the full searcher of EPG are resolved PMT, obtain each professional module information;

Each professional module information that step 410, the full searcher of EPG will obtain is saved in the traffic table in the EPG data storage;

Adopt with the same step of step 406-410 and obtain NIT, BAT, SDT, EIT; Respectively these tables are resolved; Correspondingly obtain multiplex stream information, bouquet information, business information, event information; And the information that obtains is saved in multiplex stream table, bouquet table, traffic table, event table in the EPG data storage respectively, concrete steps are seen the step 411-430 among Fig. 4.

Can find out from above-mentioned search routine; Prior art adopts serial search; Promptly adopt PAT-PMT-NIT-BAT-SDT-the EIT mode of searching for successively, need any table promptly to search for what table, if the table that multiplex stream sent in this cycle is not the table of current needs; Then abandon the table that sends, continue the table of the current needs of search; When the sort of table that needs search sends; Because this cycle abandons it, need search for again from next cycle again, like this; The table of having searched for all kinds often needs several cycles; This shows that this serial search mode search time is long, search efficiency is low, finds a kind of EPG searching method rapidly and efficiently just to seem very crucial.

Summary of the invention

In view of this, main purpose of the present invention is to provide the method for search EPG in a kind of digital television system, can under the situation that does not increase hardware cost, accelerate the speed of EPG search, improves search efficiency.

For achieving the above object, technical scheme of the present invention is achieved in that

The method of searching electric program menu EPG in a kind of digital television system, this method comprises:

A, from multiplex stream the search and filter out Program Association Table PAT, resolve said PAT;

B, according to analysis result, adopt the parallel mode search also to filter out all forms that multiplex stream sends.

Further, resolve to described in the steps A: resolve the current PAT that filters out, obtain the PID Packet Identifier PID of each professional Program Map Table PMT and the PID Packet Identifier PID of network information table NIT.

Further, all forms that send in the said multiplex stream comprise PMT, NIT, BAT bouquet association table BAT, SDT Service Description Table SDT and Event Information Table EIT.

Preferably, the said search of step B and being filtered into:

PMT PID, NIT PID, BAT PID, SDT PID, EIT PID are set,, search for and filter out all forms that multiplex stream sends according to PMT PID, NIT PID, BAT PID, SDT PID and EIT PID.

The method of search EPG in the digital television system provided by the present invention; Compare with serial search methods in the prior art; Prior art is searched for the table that multiplex stream sends according to search order, and table is current not to be needed then abandon if multiplex stream sends, and when the needs respective table, searches for again in following one-period again; Like this, searched for several transmission cycles of all EPG informational needs.And the present invention adopts parallel search method search EPG information, and multiple filter is set, and comes what table to filter what table; Search for any table simultaneously, just can search other EPG information fully in the one-period after searching pat table, just can search complete EPG information and no longer need pass through several cycles; Like this; Suppose only to transmit eight days EPG amount of information, if do not consider PAT, PMT, the search routine of a complete EPG only needs 10s; Therefore search efficiency has improved several times, and significantly reduce search time.And, can under the situation that does not increase hardware cost, accelerate the speed of EPG search, thereby improve search efficiency, for the user provides better experience impression.

Description of drawings

Fig. 1 is a broadcasting service transport model sketch map in the prior art;

Fig. 2 is that EPG information multiplexing stream transmits sketch map in the prior art;

Fig. 3 is the serial approach sketch map of search EPG in the prior art;

Fig. 4 is the serial approach schematic flow sheet of search EPG in the prior art;

Fig. 5 is the parallel method sketch map of search EPG among the present invention;

Fig. 6 is the parallel method schematic flow sheet of search EPG among the present invention.

Embodiment

Come further detailed explanation is done in practical implementation of the present invention below in conjunction with accompanying drawing:

The present invention is directed to the table of no strict processing order requirement and design, its basic thought is: adopt parallel mode to carry out the quick search of EPG.Fig. 5 is for the parallel method sketch map of search EPG among the present invention, and is as shown in Figure 5, sets the filter to various tables simultaneously, in case there is table to send, then this table filtered out.In the actual search process, PAT is the table that must search at first, filters out PAT so filter is set, and when searching PAT, resolves PAT, obtains the PID of each PMT and the PID of NIT.Because other tables do not have strict priority transmission order, can open a plurality of filters simultaneously, filter PMT, NIT, BAT, SDT and EIT respectively, the function that can realize what table promptly to filter what table thus.

Here, filter is a logical concept, in practical implementation, can be realized by hardware, also can realize that the function that filter is accomplished is from multiplex stream, to extract specific form through the software mode simulation.

In addition; The filter among the present invention and the difference of filter of the prior art are: in the prior art, can only be according to PAT->PMT->NIT->BAT->SDT->order of EIT, what table of current needs then is provided with the corresponding filter device; The table that multiplex stream is sent filters; The current unwanted table that multiplex stream sends then abandons, and like this, filters out several transmission cycles of all EPG informational needs.And the present invention is provided with a plurality of filters of all categories simultaneously, after PAT is filtered out; Can adopt each filter of setting that all forms that multiplex stream sends are filtered out one by one; Any table can not wasted, and corresponding, what table the full searcher of EPG of the present invention then can come search what table; So just shorten search time greatly, improved search efficiency.

The parallel flow process of search EPG is as shown in Figure 6 among the present invention, and this method mainly comprises following three steps:

Step 601: the tuner in the STB is provided with the search frequency to the dominant frequency point, demodulates the multiplex stream of dominant frequency point, and the multiplex stream that demodulates is transferred to filter;

Here, the multiplex stream of dominant frequency point includes all EPG information datas of whole network equally.

During the DTV operation; For making STB search for EPG fast, the multiplex stream of all EPG information forms of the whole network of transmission generally can be provided, said multiplex stream is modulated on the dominant frequency point of appointment; As long as STB demodulates this multiplex stream; Just can obtain EPG information fast, this step is just obtained the multiplex stream that comprises EPG information, and the step of back is carried out work based on this multiplex stream.

The full searcher of step 602:EPG is provided with PAT PID in filter;

Step 603: filter filters multiplex stream according to PAT PID, filters out PAT;

Step 604, the full searcher of EPG are searched for the PAT that filters out in filter;

Step 605, the full searcher of EPG are resolved PAT, obtain each professional PMT PID and NIT PID;

Step 606, the full searcher of EPG are provided with PMT PID, NIT PID, BAT PID, SDT PID, EIT PID in filter;

Step 607, filter filter multiplex stream according to PMT PID, NIT PID, BAT PID, SDT PID or EIT PID, filter out the form that sends;

Step 608, the full searcher of EPG are searched for the form that filters out in filter;

Here, because step 607 comes any form then to filter out what form, what form since the institute; The full searcher of EPG just can search any form; And unlike prior art, must search for form in order, if transmission come be unwanted form then abandon; So just shorten search time greatly, improved search efficiency.

If that filter out in step 609 step 607 is PMT, then the full searcher of EPG is resolved PMT, obtains each professional module information, and execution in step 610 then;

If that filter out in the step 607 is NIT, then the full searcher of EPG is resolved NIT, obtains multiplex stream information, and execution in step 611 then;

If that filter out in the step 607 is BAT, then the full searcher of EPG is resolved BAT, obtains bouquet information, and execution in step 612 then;

If that filter out in the step 607 is SDT, then the full searcher of EPG is resolved BAT, obtains business information, and execution in step 613 then;

If that filter out in the step 607 is EIT, then the full searcher of EPG is resolved EIT, obtains event information, and execution in step 614 then;

Each Service Component information that step 610, the full searcher of EPG will obtain is saved in the traffic table in the EPG data storage, and whole flow process finishes;

Step 611, the full searcher of EPG are saved in the multiplex stream information of obtaining in the multiplex stream table in the EPG data storage, and whole flow process finishes;

Step 612, the full searcher of EPG are saved in the bouquet information of obtaining in the bouquet table in the EPG data storage, and whole flow process finishes;

Step 613, the full searcher of EPG are saved in the business information of obtaining in the traffic table in the EPG data storage, and whole flow process finishes;

Step 614, the full searcher of EPG are saved in the event information that obtains in the event table in the EPG data storage, and whole flow process finishes.

This shows, because the present invention is provided with the filter of all categories simultaneously, after PAT is filtered out; Multiplex stream sends any form, then what form is filtered out, and is corresponding; The full searcher of EPG of the present invention then can come any table to search what table, therefore, searches in the one-period after whole EPG information only need search PAT and just can accomplish; So just shorten search time greatly, improved search efficiency.

The above is merely preferred embodiment of the present invention, is not to be used to limit protection scope of the present invention.

Claims (4)

1. the method for searching electric program menu EPG in the digital television system is characterized in that this method comprises:

A, from multiplex stream the search and filter out Program Association Table PAT, resolve said PAT;

B, according to analysis result, adopt the parallel mode search also to filter out all forms that multiplex stream sends.

2. method according to claim 1 is characterized in that, resolves to described in the steps A: resolve the current PAT that filters out, obtain the PID Packet Identifier PID of each professional Program Map Table PMT and the PID Packet Identifier PID of network information table NIT.

3. method according to claim 1 is characterized in that, all forms that send in the said multiplex stream comprise PMT, NIT, BAT bouquet association table BAT, SDT Service Description Table SDT and Event Information Table EIT.

4. according to each described method of claim 1 to 3, it is characterized in that the said search of step B also is filtered into:

PMT PID, NIT PID, BAT PID, SDT PID, EIT PID are set,, search for and filter out all forms that multiplex stream sends according to PMT PID, NIT PID, BAT PID, SDT PID and EIT PID.

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