[mythtv-users] Confusion about Output Cards.

Nick knowledgejunkie at gmail.com
Tue Mar 14 20:36:34 UTC 2006

On 14/03/06, Jesse Guardiani <jesse at wingnet.net> wrote:
> Nick Ellson wrote:
> > I am putting together a Myth TV system mainly to have menu based playback
> > of my Movie Collection (I started keeping .iso's of my kids films as they
> > tend to wreck them alot.)
> >
> > When I saw MythTV, it was as a search for a video JukeBox. While I'll
> > definately set up the whole thing, I see a lot of emphasis on input cards,
> > but my concern is getting the best audio/video output to my Sony Wega
> > HDTV and the Dream System surround sound.
> >
> > To get good quality playback from hard drive stored movies, what should I
> > be looking for? So far I have seen benefits posted on the PVR-350 for it's
> > decoder in hardware. But that's about it. What kind of connection to a
> > sound system can I expect? Or to an HDTV?
> >
> For HDTV, if you have DVI or VGA input then those are best. I think
> DVI->HDMI adapters exist
> as well. I'm using an Nvidia 5200 -> DVI -> Westinghouse 32" LCD. It's
> quite nice.
> For SDTV, the 350 is best, but many chose an nvidia card because nvidia
> cards show BIOS posts
> on tv out and have opengl accel.

Don't forget that the PVR-350, whilst awesome at displaying MPEG-2
video, is not as good at displaying other types of video or video that
is not SDTV resolution. The ivtv X driver keeps adding more features,
but unless you're only using SDTV video captured on the 350 or through
DVB, you'll most likely find you get a more usable solution using a
regular graphics card. If you use a 350, you are also limited to using
analog video output, whereas with a graphics card you can use DVI
(digital) or component (analog) for HDTV.

I purchases a PVR-350 when the ATI TV-Out driver support for my
Pundit-R system was not there, and had great results for
LiveTV/recordings. Now that the ATI driver supports TV-Out I use that
for all output and use the PVR-350 as a capture card only.

> One more note: SDTV looks fairly bad using software scaling on an HDTV.
> Usually it's perceived
> as worse than SDTV on an actual SDTV due to the pixelation. Oh well.
> DVDs look nice though,
> and of course HDTV looks great.

One question about this, as 'HD-ready' 720p panels are now becmoing
available in the UK - how does scaled DVD video or DVB look when
displayed on such a LCD/plasma screen? Is it better to use the
software to do the scaling (ala DScaler on Windows) or use the
screen's own resizing capabilities? DVB and DVD have very clean video,
whereas PVR-xx0 captured video is much more noisy, so would you expect
the same? In other words, would the pixelation observed when playing
480 content on a 720 screen be similar to playing 720 content on a
1080 screen?

By all accounts, HDTV over DVB is still some years off in the UK, and
the ability to interface a MythTV box with the coming HDTV offerings
via satellite or cable are remote, so there will be users wanting to
use SDTV DVB on a HDTV screen - I'm just wondering what to expect from
the video quality (i.e. how noticeably scaled/pixelated).


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