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Receiving two channels from one TS simultaneously

Receiving two channels from one TS simultaneously

Postby garry » Fri Oct 28, 2011 1:23 am

Hi,

Is it possible to receive two channels from one transport stream (1 tuner) simultaneously? For example, BBC World News (sid 8204) and Euronews (sid 8211) from Hotbird. I succesfully receiving only one channel: I open 2 demultiplexors (for audio and video pids) and then do 2 system calls

ioctl(dmxfd, DMX_SET_PES_FILTER, &pesfilter)

It works. But when I am trying to open demultiplexors for second channel (Euronews), I get error in this system call: Invalid argument.
Or may be it is possible to get the whole transport stream from transponder?
Last edited by garry on Fri Oct 28, 2011 2:37 pm, edited 1 time in total.
garry
 
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Re: Recieving two channels from one TS simultaneously

Postby SergioDanielG » Fri Oct 28, 2011 6:42 am

When you receive 1 channel with your software, this require lock signals and to lock requiere read/write access to the adapter. And you can't use the adatper again with other software or instance.
But if you tune and record all TS, you can see all channels independently while recording.

Best regards.
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Re: Receiving two channels from one TS simultaneously

Postby garry » Fri Oct 28, 2011 3:55 pm

Hm...
I use adapter only once in my software. I successfully set up the frontend and successfully lock signal (FE_HAS_LOCK). But to receive any data I must set up demultiplexer. If I don't do it, I can't record any data. So the problem is that I can't record all TS - only 1 channel. I can read data from dvr or demux only when I set up the demultiplexer.

From DVB API:
" The demultiplexer in your DVB system cares about the routing of an MPEG2 stream you feed into the DVB adapter either by read/write system calls, by using stream inputs of the demultiplexer or the frontend(s).
Using the demux API you can set up the stream routing and set up filters to filter the interesting parts of the input streams only.
.........
You must open the demux device once for each PES filter you want to set. E.g. if you want audio and video, you must have two distinct file descriptors for the two filters."

So if I am interested in 4 pids from TS (2 audio and 2 video) I must open frontend device once and open demux device 4 times, am I right? But now I am able to open demux device only 2 times. What is my mistake?
garry
 
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Re: Receiving two channels from one TS simultaneously

Postby garry » Tue Nov 01, 2011 3:31 pm

May be it is a bug in drivers? Anybody tried to record transport stream, more then 1 tv channel?
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