[linux-dvb] Re: I great question

[Volkmar Sieh <Volkmar.Sieh@informatik.uni-erlangen.de>]

Hi Dave!

> > But nevertheless: I'm not able to watch *all* channels and I don't know
> > why either. dvbstream doesn't generate any output for them.
> > 
> > Additionally I have an other question:
> > What's the reason for some flickering effects? mplayer shows the mpeg
> > video/audio stream but sometimes some flickering occurs and the picture
> > is unsteady. Sometimes I get Segmentation Errors by mplayer due to
> > bad mpeg stream. I crosschecked this using a different DVB-S card and a
> > different SAT disc. Same ugly effects. Any hints...?
> 
> Firstly, I'm assuming you are using a full-featured DVB card (i.e. one with a 
> TV-out).

No. It's a Nova card.

> Have you tried the "-v" and "-a" parameters when specifying the PIDs?  On 
> some transponders, this seems to make a difference to whether a clean 
> datafeed is generated by dvbstream.  

Does not make any difference.

> Also, try the "-cache 2048" parameter to mplayer - this buffers the data 
> coming from dvbstream and will often solve flickering problems.

Does not help either. Even if I first copy the video stream directly to
disk and show it using mplayer later the same ugly effects show up.
The ugly effects are the very same if I play the same mpeg file from
disk again and again.

Using some mpeg files copied from a friend who has recorded them using
vdr mplayer shows a clean movie.

But:
There are some programmes which work (e.g. most programmes of channel
"Das Erste" in Germany). But most programmes show these effects.
(Problem with different encoding?)

So the problem seems to be located in dvbstream.

No difference wheter I use

	dvbstream -f <freq> -p <pol> -s <srate> <vid> <aid>
	dumprtp | ts2ps <vid> <aid> | mplayer -

or
	dvbstream -f <freq> -p <pol> -s <srate> <vid> <aid> -o -ps | mplayer -

> If your DVB card is in the same PC as you are using to view the TV program, 
> you can just use dvbtune to tune to the channel, and then a V4L TV 
> application (e.g. xawtv) to view the channel - this uses the hardware mpeg 
> decoder on the card.  

Don't have any hardware decoder.

> You only need dvbstream/mplayer to view channels from a budget/Nova card, or 
> to stream over the network.

That's it ;-)


BTW: I tried
	dvbstream-0.3 and dvbstream-0.4pre2
	mplayer-0.90(?)
	linux-2.4.13
	siemens_dvb-0.9.4

> Dave.

Regards,
	Volkmar


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