CN103297843B - A kind of program selecting method for MPEG TS file playback - Google Patents

Abstract

The invention provides a kind of program selecting method for MPEG TS file playback, first, resolve the pat table in MPEG TS file and pmt table, obtain all programme informations in file and the stream information in program, and these streams are sorted out according to program；Then, respectively each program being checked according to the stream information of each program, this inspection at least includes: check the integrity degree of the basic stream of each program；Further according to the result checked, each program is marked；Finally, determine that each program can the sequence of selected priority according to the result of scoring.The application present invention can improve the demultiplexing efficiency of MPEG TS file, and saves the hardware resource such as CPU and internal memory.

Description

A kind of program selecting method for MPEG TS file playback

Technical field

The present invention relates to multimedia technology, particularly to a kind of program selecting method for MPEGTS file playback.

Background technology

MPEG (MovingPicturesExpertsGroup, dynamic image expert group) agreement regulation MPEGTS (TransportStream, transmission stream) file is made up of TS bag, and each TS bag is regular length 188 byte, is divided into packet header and bag load two parts.Packet header mainly includes sync byte and PID (PacketIdentifier, bag mark) and other information, and sync byte is used to refer to a TS and unwraps the beginning (value is 0x47), and PID represents the type of TS bag.Such as: the video flowing in a program, some the TS bag possessing same PID forms, and receiving terminal has only to receive the TS bag with this PID, it is possible to combination obtains the video of this program.Bag load is the actual content of bag, as the case may be, it is possible to place basic stream (PES, the PacketizedElementaryStream) bag or Program Specific Information (PSI, ProgramSpecificInformation) bag of playing bag.TS file is made up of one or more program, and each surface of revolution stream, audio stream, private information stream and other data stream are constituted.

Program Specific Information (PSI) wraps in TS file demultiplexing and occupies critical role, it is used for defining the structure of code stream, wherein most importantly Program Association Table (PAT, and Program Map Table (PMT, ProgramMAPTable) ProgramAssociationTable).Pat table is the concordance list of PSI information, and pid value is fixed as 0.Pat table lists the pid value of the pmt table of all programs in this TS file.If player wishes to play one of them program, the pmt table corresponding to this program can be parsed according to the pid value of this program, therefrom can inquire the PID of all audio streams relevant to this program, video flowing, private information stream and other data stream.

Fig. 1 is the media player demultiplexing schematic flow sheet to MPEGTS file.Local through PSI parsing, by the stream information in all programme informations obtained in MPEGTS file and program.Fig. 3 is the programme information example in a local Polymera TS file.

According to Fig. 3 example shown, owing to the pid value of pat table is 0, the pid value corresponding to the pmt table of each program can be obtained according to pat table, for instance:

The PID=336 of program 1, PMT；

The PID=352 of program 2, PMT；

The PID=432 of program 3, PMT；

The PID=544 of program 4, PMT.

It is it desired to viewing program 2, it is possible to obtain the pmt table of program 2 correspondence according to 352 these PID, further find the pid value corresponding to the video of program 2, audio frequency and private information bag, respectively 353,354 and 359.Resolve the PES bag that can be obtained by Voice & Video with the TS bag of these pid values, can be obtained by audio stream and video flowing then through the process of past bagization, deliver in the relief area of player and can be decoded, play.

Existing media player great majority all support that MPEGTS file is play.Multiple different program is deposited in MPEG agreement support in a TS file, randomness due to MPEGTS documenting, these programs can be diversified, for instance: only have audio stream, only video flowing, have audio/video flow also to have caption stream, have encrypted audio/video flow etc..Existing media player there will be exception error when playing above-mentioned special file, as media player possibly cannot start broadcasting, occurs playing phenomenon etc. that is discontinuous or that cannot continue to play and automatically exit from playing process.

Existing media player can select a default program to play out when playing back (playback) Polymera MPEGTS file.Existing media player selects the method for program mainly to include following several:

1, the program program by default at first video flowing place is selected to play out.

2, commence play out from top line, if failure, automatically select next program, until finding the suitable program that can play or having traveled through all of program.

3, played out by user specified program.

Above-mentioned prior art problem there is problems in that

1, in method 1, the program selected by media player is likely to only one of which video flowing or the encrypted mistake of selected video flowing, and this will cause that broadcasting is abnormal, bring bad experience to user.

2, the method that method 2 travels through all programs one by one due to employing, can cause the increase of File Open time.

3, the program selecting user to specify is played out by method 3, but, owing to before playing, user cannot know the relevant information of all programs in file, blindly selection can select to bring difficulty to user, and there is the problem same with method 1.

4, the efficiency that present multimedia player demultiplexes for Polymera file is not high enough, especially for the file that video resolution is higher, bit rate is relatively larger, there is the problem that demultiplexing performance is relatively low.

Summary of the invention

The invention provides a kind of program selecting method for MPEGTS file playback, to improve the demultiplexing efficiency of MPEGTS file, and save the hardware resource such as CPU and internal memory.

One provided by the invention flows the program selecting method of (TS) file playback for Polymera dynamic image expert group (MPEG) transmission, including:

Resolve the Program Association Table (PAT) in described file and Program Map Table (PMT), obtain all programme informations in file and the stream information in program；

Each program is checked by stream information according to each program respectively, and described inspection at least includes: check the integrity degree of the basic stream of each program；

Each program is marked by the result according to described inspection；

Result according to scoring determines that each program can the sequence of selected priority.

It is preferred that be the initial score S that each setting of the programs is identical in advance；

The basic stream of each program includes: video flowing, audio stream and caption stream；Check the integrity degree of the basic stream of each program as follows:

If this program does not have video flowing, button S*M1 divides, wherein: M1 is the point deduction weight factor not having video flowing corresponding；

If this program does not have audio stream, button S*M2 divides, wherein: M2 is the point deduction weight factor not having audio stream corresponding；

If this program does not have caption stream, button S*M3 divides, wherein: M3 is the point deduction weight factor not having caption stream corresponding.

It is preferred that described inspection also includes:

Check whether program exists encryption stream；

And/or whether inspection program exists splicing stream；

And/or check that whether the language of program sound intermediate frequency stream, video flowing and caption stream is consistent with the language of the equipment at player place this locality.

Preferably, check that whether there is encryption stream in program includes: find out bag mark (PID) that the basic stream of described program is corresponding, the TS packet header of corresponding PID is found transmission control extension (transport_scrambling_control) position, if value is non-zero, represent that corresponding basic stream is for encryption stream；

If video flowing is encryption stream, button S*M4 divides, wherein: M4 is the point deduction weight factor that video-encryption stream is corresponding；

If audio stream is encryption stream, button S*M5 divides, wherein: M5 is the point deduction weight factor that audio encryption stream is corresponding.

It is preferred that whether inspection program exists splicing stream include:

A1, the minimum time stamp finding out each stream in program and maximum time stamp, a minimum timestamp is selected in the minimum time of all streams stabs, it is denoted as DTS_min, a maximum timestamp is selected in the maximum time of all streams stabs, it is denoted as DTS_max, calculates the reproduction time Duration_1 of program:

$\mathrm{Duration}\_1=\frac{\mathrm{DTS}\_\max -\mathrm{DTS}\_\min }{9000}*1000000,$

Wherein: the unit of timestamp (DTS) is 90,000/second, and the unit of Duration_1 is microsecond；

A2, by the pmt table of program, find out the PID at program clock reference in program (PCR) place, read the PCR of two these programs by this PID in file beginning, it is denoted as PCR_1 and PCR_2 respectively, and two PCR side-play amount hereof is denoted as Pos_1 and Pos_2, calculate the gross bit rate Bitrate_sum of this document:

$\mathrm{Bitrate}\_\mathrm{sum}=\frac{27000000*(\mathrm{Pos}\_1-\mathrm{Pos}\_2)}{\mathrm{PCR}\_1-\mathrm{PCR}\_2}*8,$

Wherein: the unit of PCR is a system clock, and 27 megahertzs, the unit of side-play amount is byte, the unit of gross bit rate is bps；

A3, acquisition file total length File_size, calculate total reproduction time Duration_2 of program according to gross bit rate and file total length:

$\mathrm{Duration}\_2=\frac{\mathrm{File}\_\mathrm{size}*8}{\mathrm{Bitrate}\_\mathrm{sum}}*1000000,$

Wherein: the unit of Duration_2 is microsecond；

A4, compare Duration_1 and Duration_2, if the absolute value of both differences is more than 0.5*Duration_1, it is determined that this program exists splicing stream；

If there is splicing stream in program, button S*M6 divides, and wherein M6 is the point deduction weight factor that splicing stream is corresponding.

Include it is preferred that check that whether the language of program sound intermediate frequency stream, video flowing and caption stream is consistent with the language of the equipment at player place this locality:

Whether local with the equipment at player place the language comparing program Zhong Mei road audio stream, video flowing and the language in caption stream one by one consistent, if there is consistent audio stream, video flowing or caption stream, then adds S*M7 and divides, wherein: M7 is bonus point weight factor.

It is preferred that the method may further include:

The integrity degree information of ranking results and each program is supplied to user, using user-selected program as program to be played, if the non-selected program of user, then according to ranking results using the program of highest scoring as program to be played, program to be played in file is played out.

Include it is preferred that program to be played in file is played out:

In the process that file is demultiplexed, skip the data stream in other program except program to be played, only the data stream of program to be played is demultiplexed.

It is preferred that the data stream packets skipped in other program except program to be played is drawn together:

Find out the PID corresponding to all data streams in all programs；

The PID of all data streams of program to be played is labeled as use state, PID corresponding for all data streams being in the program ignoring state is labeled as unused state；

In the process that local MPEGTS bag is resolved, it is judged that whether the PID in TS packet header is use state, if the state of use, then continue executing with parsing operation, otherwise, skip this TS bag, continue to read and resolve next TS bag.

As seen from the above technical solution, program selecting method for MPEGTS file playback provided by the invention, pat table and pmt table is resolved by media player, collect the audio/video flow of all programs in MPEGTS file and the information of other data stream, comprehensive to the marking of every road program, and deduct points accordingly according to different deduction of points reasons, finally according to mark, all programs are sorted, select for user.In the nonoptional situation of user, or when media player does not provide the option interacted with user, media player acquiescence selects the program that mark is the highest to play out.Media player, in the process that file is demultiplexed, skips the data stream not having in other program selected, as such, it is possible to significantly improve the demultiplexing efficiency of file, and saves the hardware resources such as a large amount of CPU and internal memory.

And, the present invention by the way of a kind of convenient quantization to TS file in each program carry out comprehensive assessment, in order to judge the integrity degree of program self-information, user is facilitated to select suitable program to play out, it is to avoid to occur playing or to play abnormal situation.

Additionally, adopt the present invention can strengthen the ability of the abnormal local Polymera TS file of media player processes, and reduce the probability that media player is made mistakes.

Accompanying drawing explanation

Fig. 1 is the media player demultiplexing schematic flow sheet to MPEGTS file；

Fig. 2 is the schematic flow sheet of the present invention one preferably program selecting method；

Fig. 3 is the programme information example schematic diagram in a local Polymera TS file.

Detailed description of the invention

For making the purpose of the present invention, technical scheme and advantage clearly understand, develop simultaneously embodiment referring to accompanying drawing, the present invention is described in further detail.

Main idea is that: first, resolve the pat table in MPEGTS file and pmt table, obtain all programme informations in file and the stream information in program；Then, respectively each program being checked according to the stream information of each program, this inspection at least includes: check the integrity degree of the basic stream of each program；Further according to the result checked, each program is marked；Finally, determine that each program can the sequence of selected priority according to the result of scoring.

After obtaining program sequence, it is possible to the integrity degree information of ranking results and each program is supplied to user, for reference select, and using user-selected program as program to be played；If the non-selected program of user, or media player does not provide the option interacted with user, then according to ranking results using the program of highest scoring as program to be played, program to be played in file is played out, skip the data stream not having in other program selected, thus significantly improving the demultiplexing efficiency of file, and save the hardware resources such as a large amount of CPU and internal memory.

Except the integrity degree of the basic stream checking each program, it is also possible to perform the one or more combination in following inspection: check whether program exists encryption stream, check whether program exists splicing stream, check program sound intermediate frequency stream and language that whether language of video flowing is local with the equipment at player place is consistent etc..

Below by way of a preferred embodiment, the present invention is described in detail:

Media player is when playing local MPEGTS file, it is necessary to PSI is resolved by a demultiplexer according to MPEG agreement regulation, obtains all programme informations in file and the stream information in program.According to these stream informations, demultiplex out by each audio/video flow and other data stream from TS file, send into decoding in the relief area that media player is corresponding, display.

Based on the basis of stream information in the correct all programs resolved in local MPEGTS file and program, the present invention proposes the flow chart of a kind of preferably program selecting method as shown in Figure 2.Referring to Fig. 2, the method includes:

Step one: pat table in resolution file and pmt table, obtains all programme informations in file and the stream information in program.

Step 2: the initial score of program is set to S, for instance: S=100.

Step 3: checking the basic integrity degree flowed in each program, the basic stream of each program includes: video flowing, audio stream and caption stream.Specifically:

If this program does not have video flowing, button 100*M1 divides, and wherein M1 is the point deduction weight factor not having video flowing corresponding, and M1 can by user setup, and maximum is 1, and default value is 0.5；

If this program does not have audio stream, button 100*M2 divides, and wherein M2 is the point deduction weight factor not having audio stream corresponding, and M2 can by user setup, and maximum is 1, and default value is 0.2；

If this program does not have caption stream, button 100*M3 divides, and wherein M3 is the point deduction weight factor not having caption stream corresponding, and M3 can by user setup, and maximum is 1, and default value is 0.05；

Step 4: check whether there is encryption stream in program, method is as follows:

1, the PID that the basic stream of this program is corresponding is found out；

2, in the TS packet header of corresponding PID, find transmission control extension (transport_scrambling_control) position, if value is non-zero, represent that corresponding basic stream is encryption stream；

If 3 video flowings are encryption stream, button 100*M4 divides, and wherein M4 is the point deduction weight factor that video-encryption stream is corresponding, and M4 can by user setup, and maximum is 1, and default value is 0.35；

If 4 audio streams are encryption stream, button 100*M5 divides, and wherein M5 is the point deduction weight factor that audio encryption stream is corresponding, and M5 can by user setup, and maximum is 1, and default value is 0.15.

Step 5: check whether there is splicing stream in program, method is as follows:

1, minimum time stamp and the maximum time stamp of each stream in program are found out, a minimum timestamp is selected in the minimum time of all streams stabs, it is denoted as DTS_min, initial time stamp as this program, in a program the maximum time stamp of all streams selects a maximum timestamp, being denoted as DTS_max, the end time as this program stabs, and calculates the reproduction time Duration_1 obtaining program:

$\mathrm{Duration}\_1=\frac{\mathrm{DTS}\_\max -\mathrm{DTS}\_\min }{9000}*1000000,$

Wherein: the unit of timestamp (DTS) is 90,000/second, and the unit of Duration_1 is microsecond；

2, by the pmt table of program, find out the PID at program clock reference in program (PCR) place, read the PCR of two these programs by this PID in file beginning, it is denoted as PCR_1 and PCR_2 respectively, and the side-play amount that two PCR are hereof, it is denoted as Pos_1 and Pos_2, calculates the gross bit rate Bitrate_sum obtaining this document:

$\mathrm{Bitrate}\_\mathrm{sum}=\frac{27000000*(\mathrm{Pos}\_1-\mathrm{Pos}\_2)}{\mathrm{PCR}\_1-\mathrm{PCR}\_2}*8,$

Wherein: the unit of PCR is a system clock (27 megahertzs), and the unit of side-play amount is byte, the unit of gross bit rate is bps；

3, obtain file total length File_size, calculate total reproduction time Duration_2 of program according to gross bit rate and file total length:

$\mathrm{Duration}\_2=\frac{\mathrm{File}\_\mathrm{size}*8}{\mathrm{Bitrate}\_\mathrm{sum}}*1000000,$

Wherein: the unit of Duration_2 is microsecond；

4, compare Duration_1 and Duration_2, if the absolute value of both differences is more than 0.5*Duration_1, then judges that this program is as splicing stream, and timestamp is discontinuous；

5, being discontinuous program for that spliced and timestamp, button 100*M6 divides, and wherein M6 is the point deduction weight factor that splicing stream is corresponding, and M6 can by user setup, and maximum is 1, and default value is 0.25.

Step 6: check that whether program sound intermediate frequency stream, video flowing be consistent with the language of the equipment at player place this locality with the language of caption stream, specifically:

Whether local with the equipment at player place the language comparing program Zhong Mei road audio stream, video flowing and the language in caption stream one by one be consistent, if there is consistent audio stream, video flowing or caption stream, then add S*M7 to divide, wherein: M7 is bonus point weight factor, M7 can by user setup, maximum is 1, and default value is 0.1.

Step 7: the best result limiting each program is 100 points, minimum is divided into 0 point, till having detained；

Step 8: judged whether the inspection to each program and scoring, checking if it is not complete, return step 2 next program and marks, if completed, continuing step 9.

Step 9: by the comprehensive grading of programs all in file, be ranked up by order from high to low, and show ranking results, selects to play for user.

Step 10: in the process that file is demultiplexed, skips the data stream in other program except program to be played, only the data stream of program to be played is demultiplexed.Such as: by the setting of the programs not being easily selected by a user for ignoring state, parsing, splicing namely can not gone when TS file demultiplexes to belong to all audio/video flows ignoring state program and other data stream, to improve demultiplexing performance, reduce resource and use.Concrete grammar is as follows:

Find out the PID corresponding to all data streams in all programs；

The PID of all data streams of program to be played is labeled as use state, PID corresponding for all data streams being in the program ignoring state is labeled as unused state；

In the process that local MPEGTS bag is resolved, it is judged that whether the PID in TS packet header is use state, if the state of use, then continue executing with parsing operation, otherwise, skip this TS bag, continue to read and resolve next TS bag.

So far, method flow shown in Fig. 2 is terminated.

As seen from the above-described embodiment, program selecting method for MPEGTS file playback provided by the invention, pat table and pmt table is resolved by media player, collect the audio/video flow of all programs in MPEGTS file and the information of other data stream, comprehensive to the marking of every road program, and deduct points accordingly according to different deduction of points reasons, finally according to mark, all programs are sorted, select for user.In the nonoptional situation of user, or when media player does not provide the option interacted with user, media player acquiescence selects the program that mark is the highest to play out.Media player, in the process that file is demultiplexed, skips the data stream not having in other program selected, as such, it is possible to significantly improve the demultiplexing efficiency of file, and saves the hardware resources such as a large amount of CPU and internal memory.

And, the present invention by the way of a kind of convenient quantization to TS file in each program carry out comprehensive assessment, in order to judge the integrity degree of program self-information, user is facilitated to select suitable program to play out, it is to avoid to occur playing or to play abnormal situation.

Additionally, adopt the present invention can strengthen the ability of the abnormal local Polymera TS file of media player processes, and reduce the probability that media player is made mistakes.

The foregoing is only presently preferred embodiments of the present invention, not in order to limit the present invention, all within the spirit and principles in the present invention, any amendment of making, equivalent replacement, improvement etc., should be included within the scope of protection of the invention.

Claims (9)

1. the program selecting method for Polymera dynamic image expert group mpeg transport stream TS file playback, it is characterised in that:

Resolve the Program Association Table PAT in described file and Program Map Table PMT, obtain all programme informations in file and the stream information in program；

Each program is checked by stream information according to each program respectively, and described inspection at least includes: check the integrity degree of the basic stream of each program；

Each program is marked by the result according to described inspection；

Result according to scoring determines that each program can the sequence of selected priority.

2. method according to claim 1, it is characterised in that:

It is the initial score S that each setting of the programs is identical in advance；

The basic stream of each program includes: video flowing, audio stream and caption stream；Check the integrity degree of the basic stream of each program as follows:

If this program does not have video flowing, button S*M1 divides, wherein: M1 is the point deduction weight factor not having video flowing corresponding；

If this program does not have audio stream, button S*M2 divides, wherein: M2 is the point deduction weight factor not having audio stream corresponding；

If this program does not have caption stream, button S*M3 divides, wherein: M3 is the point deduction weight factor not having caption stream corresponding.

3. method according to claim 2, it is characterised in that described inspection also includes:

Check whether program exists encryption stream；

And/or whether inspection program exists splicing stream；

And/or check that whether the language of program sound intermediate frequency stream, video flowing and caption stream is consistent with the language of the equipment at player place this locality.

4. method according to claim 3, it is characterised in that:

Check that whether there is encryption stream in program includes: find out the bag mark PID that the basic stream of described program is corresponding, the TS packet header of corresponding PID is found transmission control extension transport_scrambling_control position, if value is non-zero, represent that corresponding basic stream is for encryption stream；

If video flowing is encryption stream, button S*M4 divides, wherein: M4 is the point deduction weight factor that video-encryption stream is corresponding；

If audio stream is encryption stream, button S*M5 divides, wherein: M5 is the point deduction weight factor that audio encryption stream is corresponding.

5. method according to claim 3, it is characterised in that:

Check that whether there is splicing stream in program includes:

A1, the minimum time stamp finding out each stream in program and maximum time stamp, a minimum timestamp is selected in the minimum time of all streams stabs, it is denoted as DTS_min, a maximum timestamp is selected in the maximum time of all streams stabs, it is denoted as DTS_max, calculates the reproduction time Duration_1 of program:

$Duration\_1=\frac{DTS\_max-DTS\_min}{90000}*1000000,$

Wherein: the unit of timestamp DTS is 90,000/second, the unit of Duration_1 is microsecond；

A2, by the pmt table of program, find out the PID at program clock reference PCR place in program, read the PCR of two these programs by this PID in file beginning, it is denoted as PCR_1 and PCR_2 respectively, and two PCR side-play amount hereof is denoted as Pos_1 and Pos_2, calculate the gross bit rate Bitrate_sum of this document:

$Bitrate\_sum=\frac{27000000*(Pos\_1-Pos\_2)}{PCR\_1-PCR\_2}*8,$

Wherein: the unit of PCR is a system clock, and 27 megahertzs, the unit of side-play amount is byte, the unit of gross bit rate is bps；

A3, acquisition file total length File_size, calculate total reproduction time Duration_2 of program according to gross bit rate and file total length:

$Duration\_2=\frac{File\_size*8}{Bitrate\_sum}*1000000,$

Wherein: the unit of Duration_2 is microsecond；

A4, compare Duration_1 and Duration_2, if the absolute value of both differences is more than 0.5*Duration_1, it is determined that this program exists splicing stream；

If there is splicing stream in program, button S*M6 divides, and wherein M6 is the point deduction weight factor that splicing stream is corresponding.

6. method according to claim 3, it is characterised in that:

Check that whether the language of program sound intermediate frequency stream, video flowing and caption stream is consistent with the language of the equipment at player place this locality to include:

Whether local with the equipment at player place the language comparing program Zhong Mei road audio stream, video flowing and the language in caption stream one by one consistent, if there is consistent audio stream, video flowing or caption stream, then adds S*M7 and divides, wherein: M7 is bonus point weight factor.

7. the method according to any one of claim 1 to 6, it is characterised in that the method farther includes:

The integrity degree information of ranking results and each program is supplied to user, using user-selected program as program to be played, if the non-selected program of user, then according to ranking results using the program of highest scoring as program to be played, program to be played in file is played out.

8. method according to claim 7, it is characterised in that program to be played in file is played out and includes:

In the process that file is demultiplexed, skip the data stream in other program except program to be played, only the data stream of program to be played is demultiplexed.

9. method according to claim 8, it is characterised in that the data stream packets skipped in other program except program to be played is drawn together:

Find out the PID corresponding to all data streams in all programs；

The PID of all data streams of program to be played is labeled as use state, PID corresponding for all data streams being in the program ignoring state is labeled as unused state；

In the process that local MPEGTS bag is resolved, it is judged that whether the PID in TS packet header is use state, if the state of use, then continue executing with parsing operation, otherwise, skip this TS bag, continue to read and resolve next TS bag.