[mythtv-users] DVB questions

[jason bright]

Hello All

I've got a DVB system up and running and had some questions about the
configuration options.

(sorry if this is a bit inspecific - i'm not in near the myth box at
the moment).

I think i'm having quality issues and i'm trying to figure out where
to look next. The graphics card is an nVidia5200 and I'm using the DVI
output so the signal isn't going to get any cleaner. If memory serves
I'm using libmpeg for decoding. The capture card is a fusionHTDV lite.
I haven't mucked with the X11 settings at all other than what is
required by Jarods guide.

If I go into the system settings and to the recording profiles and go
to the DVB capture card, there are a pile of options - image size,
codec (RTJpeg, MPEG4, etc), quality settings, etc etc.

Now correct me if i'm wrong, but isn't the DVB card supposed to just
capture the raw MPEG transmission stream. So - why do we have these
options? Do these parameters actually do anything? And if they do,
what is going to give me the best quality? Just turn them all the way
up?

To describe the problem - the output image just doesn't look as clean
as I remember using a dedicated DVB STB. I don't have one on hand to
compare directly but i'm going to borrow one for some tests. For
something like a newscast where the background is a reasonably
constant solid color there is quite a bit of jitter and crawling and
what looks like jpeg-y compression artifacts.  2001:A Space Odyssey
was on the other night and the black monolith around Jupiter looked a
real mess.

Any pointers appreciated!
j