[vdr] Need advices about device plugin development.

["Philippe" <philippe@accuitee.com>]

Hi,

I need advices about the PES demux process which should be done before
feeding a decoder. My device output is not as smooth as the DVB output

My hardware decoder is a sigmadesigns em847x mpeg 1/2/4 decoder

Let me explain :
- I stole some code from the softPlugin and the dxr3Plugin to write my
em84plugin. 
 - The osd is OK
 - The video is playing (not really smooth because I have to feed the
decoder with bigger chunks)
 - The audio is playing
 - The synchro is not really good (I have a little delay depending on the
channel I’m viewing)

Technicaly the decoder of this device need to be fed with a special data
structure :

myDataStructure dataToSend ;

dataToSend.pData = inbuf_ptr ; // pointer to an elementary stream buffer
(audio or video)
dataToSend.DataLeft = length ; // length of the buffer
dataToSend.Pts = pts ; 
dataToSend.Dts = dts ;

Here are my troubles :
1) it seems that the video decoder need to be fed with chunks of ~ 4000
bytes (the video is smoother)
2) There is a constant delay between audio and video (the delay differs on
each channel)

Now my questions :
1) If I find a pts /dts in the pes header, do i need to send the pts/dts
with a special element (ex : the pts must be sent with a
start_sequence_code) .

2) How can I have pes packet with a bigger payload ? Is it possible to
change a VDR parameter to force the remux process to send packets of 4096
bytes ?
I could join the packet myself but as there is a remux process, I would
prefer to use it.

3) I  saw many different ways to code the demuxer/decoder. I was interested
by the dxr3 demuxing code but I wasn't able to understand it. It would be
great if the dxr3 developers could explain me in a simple way (the code is
really complex) how they have created their demuxer / decoder feeder. It
should be usefull for me.

Thank you

Philippe





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