[dvbtools-devel] No audio, and interlacing problem with Nova-t card and dvbstream

[<jng...@gr...>]

Hi there. I'd be extremely grateful if there is anybody out there who 
could help me with a few simple DVB related problems. I have recently 
bought a Hauppauge Nova-t card and I am trying to get it working with 
Linux (it works fine on Windows, but that's no use!).

By the way, I hope this is a good mailing list / forum for these 
questions. Please redirect me if there is a more appropriate place.

I checked out the latest DVB drivers, and latest dvbstream. I built them 
without any problems. The problem comes when I try to watch live TV. I'm 
using mplayer to play the MPEG stream. But I've encountered a few 
problems:

1) Tuning in the card. If I use 'tzap' that comes with the DVB driver, I
can tune in the card. 'scan' also works fine, and builds me a sensible 
looking channels.conf. But 'dvbstream' and 'dvbtune' seem to have a 
problem tuning in the card. I don't know if this is correct but I used 
some of the settings from my channels.conf for arguments to 'dvbstream'. 
For example, I have the following line in my channels.conf:

BBC ONE:641833330:INVERSION_OFF:BANDWIDTH_8_MHZ:FEC_3_4:FEC_NONE:QAM_16:TRANSMISSION_MODE_2K:GUARD_INTERVAL_1_32:HIERARCHY_NONE:600:602

So I did something like this:

dvbstream -f 641833330 -qam 16 -cr 3_4 -o 8192 | ts2pes 600 602 | mplayer -

It doesn't work, but I noticed the following line in the output:

tuning DVB-T (in United Kingdom) to 1883202896 Hz

Obviously the frequency isn't what I specified at the command line - so
I'm not quite sure what is going on here. Any help here would be much 
appreciated.

If I don't specify any of the tuning parameters to 'dvbstream' but use 
'tzap' instead, I can get a live picture in mplayer, ie:

tzap "BBC ONE"
dvbstream -o 8192 | ts2pes 600 602 | mplayer -

I must say it was a big relief to get some kind of video coming out of 
the system. But this leads me on to problem two:

2) When I get a live picture playing in mplayer, I nearly always don't get
any sound/audio. On two occasions I have got sound but it wasn't through
any reasoned method. I found that in the example above I managed to get
sound by doing the following:

tzap "BBC ONE"
./dvbstream -o 8192 | ./ts2pes 600 601 | mplayer -

The difference is the arguments to 'ts2pes'. I specified ID 601 instead of 
602. This differs to what my channels.conf says. Either there's a bug in 
'scan' (which I doubt), or I've misunderstood something?

3) Finally, when I do get working video, all is fine until there is rapid
motion in the animation. Under these conditions I get some pretty horrible
looking interlacing problems. The effect can be seen if somebody waves
their hands.  Lots of horizontal stripes appear around the fast moving
hands. It's as though alternate lines are plotted at the wrong horizontal
offset. It's definitely some kind of interlacing problem - I have seen it
before on DVD playback when I have got the wrong interlace settings. But I
don't know how to change the settings in the DVB world. Again any help
here would be much appreciated?

So, if anybody can help me I'd be very grateful. If I can get things
working I hope to develop some useful DVB software, so I can hopefully
repay any help back to the community.

Thanks,

James.