Retrieve EPG from MPEG2 TS (TsWriter?) (1 Viewer)

[Acheros]

Hi,

I'd like to know whether it's possible to get EPG information from an MPEG2 Transport Stream programmatically.

The idea is to build up a DirectShow graph basically looking like this:

MPEG2 TS -> TsWriter? -> EPG_info_into_file

I've had a look at TsWriter. While it does accept an MEDIASUBTYPE_MPEG2_TRANSPORT at the Input pin, I don't see any output pins created. CMpTsFilter::GetPinCount() in TsWriter.cpp in the current SVN also just returns 1. So I assume that I have no chance of having an output pin to somehow get the data.

I don't have a DVB-card/tuner, just the plain MPEG2 TS with EPG data in it.

Thanks,
Acheros

 

[miroslav22]

I believe tswriter is just a sink filter and never has an output pin. You would have to parse and extract the EPG data from within the tswriter code.

 

[tourettes]

Have a look on:

DECLARE_INTERFACE_(ITsEpgScanner, IUnknown)
{
	//epg
	STDMETHOD(GrabEPG)(THIS_)PURE;
	STDMETHOD(IsEPGReady) (THIS_ BOOL* yesNo)PURE;
	STDMETHOD(GetEPGChannelCount) (THIS_ ULONG* channelCount)PURE;
	STDMETHOD(GetEPGEventCount) (THIS_ ULONG channel, ULONG* eventCount)PURE;
	STDMETHOD(GetEPGChannel) (THIS_ ULONG channel, WORD* networkId, WORD* transportid,WORD* service_id  )PURE;
	STDMETHOD(GetEPGEvent) (THIS_ ULONG channel, ULONG eventid,ULONG* language,ULONG* dateMJD,ULONG* timeUTC,ULONG* duration,char** genre,int* starRating,char** classification    )PURE;
	STDMETHOD(GetEPGLanguage) (THIS_ ULONG channel, ULONG eventid,ULONG languageIndex,ULONG* language,char** eventText, char** eventDescription, unsigned int* parentalRating  )PURE;

	//mhw
	STDMETHOD(GrabMHW)()PURE;
	STDMETHOD(IsMHWReady) (THIS_ BOOL* yesNo)PURE;
	STDMETHOD(GetMHWTitleCount)(THIS_ UINT* count)PURE;
	STDMETHOD(GetMHWTitle)(THIS_ UINT program, UINT* id, UINT* transportId, UINT* networkId, UINT* channelId, ULONG* programId, UINT* themeId, UINT* PPV, BYTE* Summaries, UINT* duration, ULONG* dateStart, ULONG* timeStart,char** title,char** programName)PURE;
	STDMETHOD(GetMHWChannel)(THIS_ UINT channelNr, UINT* channelId, UINT* networkId, UINT* transportId, char** channelName)PURE;
	STDMETHOD(GetMHWSummary)(THIS_ ULONG programId, char** summary)PURE;
	STDMETHOD(GetMHWTheme)(THIS_ UINT themeId, char** theme)PURE;
	STDMETHOD(Reset)(THIS_)PURE;
	STDMETHOD(AbortGrabbing)(THIS_)PURE;
  
	STDMETHOD(SetCallBack)(THIS_ IEpgCallback* callback)PURE;
};

 

[Acheros]

Thanks for your replies. I've had a look at the code, but there are some things i don't understand yet.

If the TsWriter.ax has no output pins, how do you guys from Mediaportal use it and where does it sink it's data to? I don't get what this filter currently does

Is it possible to rewrite the TsWriter.ax filter in such a way, that it outputs EPG data to a file? I just need to know whether it's theoretically feasible.

Do you have any further information on this filter? Unfortunately, the code doesn't provide too many comments and I couldn't find much documentation on this.

Thanks

 

[miroslav22]

Its main functions are:

Filters the relevant pids from the mux and writes the transport stream files to disk for live tv/recording (this is why no output pin is needed - nothing is rendered in this graph)

Channel scanning - Scans the nit, sdt etc from a mux to let MP know about network/channel information for a transponder
EPG scanning - Scans relevant pids/tables for EPG data to be sent back to MP and inserted into the database

You should be able to do what you require - you just need to change the code to filter and process the pids containin the data you are interested in. You can then write this to disk or do what you need with it within tswriter.

 

[gemx]

The filter indeed has no output pin.

It writes the wanted channel inside a tuned transponder to disk and also parses the PID tables.

The EPG info is stored in some pids depending on the broadcaster.

TsWriter gathers the EPG and stores them in memory.

In order to get the EPG entries you have to use the "ITsEpgScanner" interface.

Basically the following steps are requiered:

1) call "GrabEPG()" to start grabbing the EPG infos
2) check "IsEPGReady" to see if EPG grabbing has finished
3) call "GetEPGChannelCount" to get the number of channels for which there are entries
4) call "GetEPGChannel" to get the ids that describe the channel inside the current transponder
5) call "GetEPGEventCount" to get the number of events for the desired channel
6) call "GetEPGEvent" for all events for all channels

Here is a little example (without error checking etc.)

  GrabEPG();
  bool isEPGReady=false;
  while (isEPGReady)
  {
     IsEPGReady(&isEPGReady);
     sleep(10);
   }
   ulong channelCount=0;
   GetEPGChannelCount(&channelCount);
   for (int i=0;i<channelCount;i++)
   {
      ulong eventCount;
      GetEPGEventCount(i,&eventCount);
      for (int j=0;j<eventCount;j++)
      {
        GetEPGEvent(i,j,.....);
        ....
      }
   }

STDMETHOD(GrabEPG)(THIS_)PURE;
STDMETHOD(IsEPGReady) (THIS_ BOOL* yesNo)PURE;
STDMETHOD(GetEPGChannelCount) (THIS_ ULONG* channelCount)PURE;
STDMETHOD(GetEPGEventCount) (THIS_ ULONG channel, ULONG* eventCount)PURE;
STDMETHOD(GetEPGChannel) (THIS_ ULONG channel, WORD* networkId, WORD* transportid,WORD* service_id )PURE;
STDMETHOD(GetEPGEvent) (THIS_ ULONG channel, ULONG eventid,ULONG* language,ULONG* dateMJD,ULONG* timeUTC,ULONG* duration,char** genre,int* starRating,char** classification )PURE;
STDMETHOD(GetEPGLanguage) (THIS_ ULONG channel, ULONG eventid,ULONG languageIndex,ULONG* language,char** eventText, char** eventDescription, unsigned int* parentalRating )PURE;