CN101656842B

CN101656842B - Single frequency point quick channel search method of digital television

Info

Publication number: CN101656842B
Application number: CN200810141961A
Authority: CN
Inventors: 邹建宇
Original assignee: Shenzhen TCL New Technology Co Ltd
Current assignee: Shenzhen TCL New Technology Co Ltd
Priority date: 2008-08-22
Filing date: 2008-08-22
Publication date: 2012-09-05
Anticipated expiration: 2028-08-22
Also published as: CN101656842A

Abstract

The invention is suitable for digital televisions and provides a single frequency point quick channel search method of a digital television, which comprises the following steps: a, resolving PAT tables to acquire PMT PID and Program Number of a program contained in the current TS stream; and b, filtering by the PMT PID to obtain PMT tables, and using the Program Number as service id for filtration to acquire current SDT tables. The method adopts the technical scheme that the PAT table is filtered first, then the characteristics of PSI/SI information are filtered by a Ts demultiplexing module,having a plurality of channels, of the digital television, and finally all PMT and SDT tables are filtered synchronously by using a plurality of channels and the associativity of the Program Number and the service id to improve the speed of the single frequency point channel search of the digital television.

Description

The method of DTV single frequency point quick channel search

Technical field

The invention belongs to TV technology, relate in particular to a kind of method of DTV single frequency point quick channel search.

Background technology

DTV is promoted just throughout the country and can finally be substituted simulated television, and there is bigger difference in both on operation principle, comprising searching the platform mode.Variation change stepping according to the line of frequently buckling when simulated television is searched platform progressively scans from the low frequency to the high frequency; And according to the analog signal decoder module read row, the field synchronization status data is accomplished the platform process of searching of analog signal, during programs stored also as long as preserve relevant frequency information.

And the location digital television program not only need be known frequency and relevant modulation parameter; Also need know the program video PID (Packet Identifier, PID Packet Identifier) of DTV, audio frequency PID; PCR PID parameters such as (Program Clock Reference, program clock references).Therefore DTV is searched platform and also need be analyzed other information in the MPTS (TS), like PAT (Program Association Table, Program Association Table); PMT (Program Map Table; Program Map Table), SDT contents such as (Service Descript Table, service describing tables); These tables are referred to as PSI/SI table (Program Service Information/Service Information, program specific information/information on services).These parameters and information are specified as follows:

PSI is how the heterogeneity in different programs of regulation and the program is multiplexed into a unified code stream.With PSI is the formation that the basis can provide a code stream, thereby helps the user that program is selected; SI comprises some extend informations, has added some to user's Useful Information, indicates the type of program, service provider, the correlation of program etc.;

The PID of pat table be fix 0 * 0000, its main effect is to point out this MPTS ID (identifier), and the pmt table and the PMT PID of pairing several roads program stream in this road MPTS.

Pmt table: the PID of this table is provided by PAT, can obtain the information that comprises in one road program through this table, and for example, this road program constitutes the type (video, audio frequency, data) with these streams, the corresponding PID of each stream in the appointed program by which stream.

Search in the platform method of velocity at existing raising DTV, various technical schemes still mainly realize with raising scanning frequency, quickening tuned speed, adopt the order of PAT-PMT-SDT to carry out when PSI/SI information is read in decoding usually.This method is failed the top performance of the system that brings into play, and searches platform speed and neither optimizedly design.

Summary of the invention

The object of the present invention is to provide a kind of method of DTV single frequency point quick channel search, be intended to solve in the prior art DTV single frequency point and search the slow excessively problem of platform speed.

The present invention is achieved in that a kind of method of DTV single frequency point quick channel search, and described method comprises the steps:

A, resolve the Program Association Table pat table, obtain to comprise in the current transport stream TS packet identifier PMT PID and the program number thereof of the Program Map Table of program;

B, filter through said PMT PID and to obtain the Program Map Table pmt table, adopt a plurality of passages to carry out synchronous filtering as service account numbers program number simultaneously, obtain current service description list SDT table.

Wherein also comprise before the step a:

A0, locked frequency point, receiving digital television signal filters said pat table from said digital television signal.

Wherein step a0 specifically comprises:

With the frequency setting of digital TV tuner is a frequency values; Lock a frequency; The input channel decoder module carries out channel-decoding behind the said tuner receiving digital television high-frequency signal; Output TS flows the demultiplexing module to TS behind the channel-decoding, and said TS demultiplexing module is decomposed into audio stream and video flowing and auxiliary data with said TS stream, from said auxiliary data, filters pat table.

Wherein step a specifically comprises:

A1, analyze said pat table structure, obtain the PMT of the program that is comprised in the said current TS stream

PID obtains the program number of said program simultaneously.

Wherein step b specifically comprises:

B1, TS demultiplexing module are filtered through said PMT PID and are obtained said pmt table, obtain the video stream packets identification code PID and the audio stream packet identifier PID of said program; Simultaneously, said TS demultiplexing module is utilized the relevance of said program number and service account numbers, and said program number is filtered as service account numbers, obtains said current SDT table, and obtains the programm name of said program.

Wherein also comprise after the step b:

C, said pmt table and current SDT table information are inserted program database.

The present invention overcomes the deficiency of prior art; Have the frequency of digital television signal in system lock after; At first filter pat table, utilize the TS demultiplexing module of DTV to have the advantages that a plurality of passages can filter PSI/SI information then, utilize the relevance of program number and service account numbers; Adopt all PMT of a plurality of passage synchronous filterings and SDT table, to improve the platform speed of searching of DTV single frequency point.

Description of drawings

Fig. 1 is the relation of the embodiment of the invention PAT, PMT, SDT and the program data that provide;

Fig. 2 is the working method sketch map of the TS demultiplexing module that provides of the embodiment of the invention;

Fig. 3 is an embodiment of the invention flow chart.

Embodiment

Technical scheme provided by the invention is: have the frequency of digital television signal in system lock after; At first filter pat table; Utilize the TS demultiplexing module of DTV to have the advantages that a plurality of passages can filter PSI/SI information then, utilize the relevance of Program Number and service id, adopt all PMT of a plurality of passage synchronous filterings and SDT table; And then parsing obtains the essential information of digital television program; And it is inserted program database, be saved in the memory at last, thereby realize quick channel search.

In order to make the object of the invention, technical scheme and advantage clearer,, the present invention is further elaborated below in conjunction with accompanying drawing and embodiment.Should be appreciated that specific embodiment described herein only in order to explanation the present invention, and be not used in qualification the present invention.

The DTV its working principles is: tuner from antenna receiving digital television high-frequency signal, is delivered to the IF process module after frequency-selecting under CPU control, carries out channel-decoding through amplifying, go processing back input channel decoder modules such as IF carrier.Output transport stream behind the channel-decoding (TS) is given the TS demultiplexing module.The TS demultiplexing module is decomposed into audio stream and video flowing and auxiliary data with above-mentioned MPTS, comprises PSI/SI information such as PAT, PMT, SDT in the auxiliary data.These auxiliary datas above the TS demultiplexing module is filtered, thus programm name obtained, and play data such as needed video PID, audio frequency PID, PCR PID.For the video data that filtration obtains, carry out the MPEG2 decoding earlier, pass through Deinterlacing (going interlacing), Scaling Video processing such as (convergent-divergents) again, deliver to display device then and show.Sound stream or voice signal then will pass through filtration equally, deliver to loudspeaker plays after MPEG2 decoding, audio frequency and audio processing and the amplification.

Digital television system also has memory device to be provided with and reference data via various data and user in the memory interface storage decoding, comprises the data of the required preservation of system, like frequency meter, and the rendition list etc.Memory device comprises RAM and NVRAM (non-volatile ram).

At first consult Fig. 1, the relation of PAT, PMT, these three tables of SDT and program data is described.As can be seen from Figure 1 the TS demultiplexing module obtains to have comprised several roads program in the current TS stream through resolving pat table, and the PMT PID of these programs, obtains the program number (Program Number) of these programs simultaneously.Filter through PMT PID again and obtain pmt table, just can obtain the pid informations such as video flowing, audio stream of each program.In the technical scheme provided by the invention, system can go to obtain current SDT table through filtration as service id with Program Number, has so just obtained the programm name of each program.

In addition, the working method of TS demultiplexing module once is described again, with reference to Fig. 2 here; Common TS demultiplexing module is a double-layer structure, and the front is the filtration that passage (Slot or Channel) is used for PID, and then is the filtration that filter (Filter) is used for the PSI/SI table; This double-layer structure be connected with a variety of modes, modal is dual mode as shown in Figure 2, first kind is exactly the corresponding Filter of a Slot; Corresponding then circular buffering is shown in (1) among Fig. 2; Second kind is exactly the corresponding a plurality of Filter of a Slot, and the corresponding separately circular buffering of each Filter is shown in (2) among Fig. 2.

In the technical scheme provided by the invention; After system has obtained pat table; Just can obtain PMT PID and Program Number, utilize then and filter needed Service id of SDT and Program Number relevance, TS demultiplexing module a plurality of passage synchronous filtering pmt table and and SDT table.The TS demultiplexing module of common digital television chip all has 32 slot and 32 Filter at least.Filter PMT and use first kind among Fig. 2 to filter connected mode, and a TS stream generally has only 6～10 programs, this is just corresponding 6～10 PMT PID, just 6～10 couples of Slot and Filter.Filtering SDT also needs a pair of Slot and Filter, and this need use second kind among Fig. 3 to filter connected mode (because in the represented stream of SDTPID, the SDT table is arranged not only, also have other table, this is the DVB prescribed by standard and which shows a shared PID).Therefore, parallel filtering PMT and SDT table only need take 7～11 couples of Slot and Filter on single frequency point, and hardware resource can satisfy the synchronous filtering requirement.

See also Fig. 3, the flow process for the embodiment of the invention specifically comprises the steps:

1, system is a frequency values with the frequency setting of tuner, locks a frequency (like 666MHz);

2, tuner receiving digital television high-frequency signal amplifies, goes processing such as IF carrier back input channel decoder module to carry out channel-decoding, and output transport stream behind the channel-decoding (TS) is given the TS demultiplexing module;

3, the TS demultiplexing module is decomposed into audio stream and video flowing and auxiliary data with above-mentioned MPTS, from auxiliary data, filters pat table;

4, through analyzing the pat table structure, extract data such as PMT PID and Program Number;

5, a plurality of passages of TS demultiplexing module filter according to PMT PID and obtain pmt table; Obtain the information such as video flowing PID, audio stream PID of each program; Simultaneously; The a plurality of passages of TS demultiplexing module as the current SDT table of service id synchronous filtering, obtain the programm name of each program with Program Number;

6, judge whether to accomplish the search of all programs in this TS stream? If change step 7, otherwise change step 3;

7, will search platform to program data be saved in NVRAM, finish the program searching of this frequency.

The above is merely preferred embodiment of the present invention, not in order to restriction the present invention, all any modifications of within spirit of the present invention and principle, being done, is equal to and replaces and improvement etc., all should be included within protection scope of the present invention.

Claims

1. the method for a DTV single frequency point quick channel search is characterized in that, described method comprises the steps:

A, resolve Program Association Table PAT, obtain to comprise in the current transport stream TS packet identifier PMT PID and the program number thereof of the Program Map Table of program;

B, filter through said PMT PID and to obtain the Program Map Table pmt table, adopt a plurality of passages to carry out synchronous filtering as service account numbers program number simultaneously, obtain current service description list SDT.

2. method according to claim 1 is characterized in that, wherein also comprises before the step a:

3. method according to claim 2 is characterized in that, wherein step a0 specifically comprises:

4. method according to claim 1 is characterized in that, wherein step a specifically comprises:

A1, analyze said pat table structure, obtain the PMT PID of the program that is comprised in the said current TS stream, obtain the program number of said program simultaneously.

5. method according to claim 1 is characterized in that, wherein step b specifically comprises:

6. method according to claim 1 is characterized in that, wherein also comprises after the step b: