[mythtv-users] Re: Mythtv, nvidia and tvout

Chris Vargas ceenvee at yahoo.com
Tue Jul 13 12:29:03 EDT 2004

--- Brian wrote:
> I have been trying to get optimal picture in my 
> mythtv setup for many months now. My problem is 
> smooth playback...it seems to me that optimally, my
> picture in MythTV should be of comparable quality 
> to my picture straight out of the 
> cable box into the TV.

I think what both you and Thomas are seeing is the
loss of interlaced playback of your interlaced PVR-x50
recordings via the nVidia TV-out. 

If you have "deinterlace" turned on in MythTV
playback, or if your TV out doesn't support
"passthrough" of interlaced material (and thus is
deinterlacing it), you will see a difference in
viewing TV live vs. a recording. 

This will be most obvious in sports or live TV (since
it started out as interlaced), and not as obvious in
filmed material (since it started out as progressive
(i.e. deinterlaced)).

There are two recent long thread discussing this:


There is one message in the second thread that was as
close as I saw to a description on how to set up the
TV-out so that the fields are maintained and passed
through to the interlaced TV out (which is what the
PVR-350 does, and why motion looks the same as the
live signal).


I haven't tried this yet but may do so soon, just to
see if it can be done.

Note that running at any resolution that scales your
recorded signal's dimensions, either up or down, will
effectively deinterlace your source, and you'll see
the motion effects again.

Some people have also reported better results with the
new nVidia drivers and using the "HD480i" TVStandard

But IMO, this isn't really a case of "better" or
"worse": it's a case of "right" and "wrong." You can
certainly make the "wrong" case look better, via
deinterlacing, etc. But it is basically just masking
the issue.

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