[mythtv-users] pcHDTV with FX5200 TV-Out

Dan Lanciani ddl5 at danlan.com
Sun Oct 24 08:01:47 UTC 2004

I've been playing with the TV-Out on an FX5200 to display ATSC content from
a pcHDTV.  I see a lot of motion artifacts in the form of short black lines
around moving objects.  I'm not at all sure that these are (de)compression
artifacts as I have seen similar problems caused by color encoder or interlace
glitches.  In any case, the same program on the same TV sourced from an old
DTC-100 shows no problems, so it isn't intrinsic to the stream.  Is there
anything I should be tweaking or should I look for a different TV-Out card?
(And if a different card, which one?)  I am using the latest driver from
nvidia's site.

A couple of other things I noticed:

The driver seems to ignore the TVOverScan option, and it really needs some
overscan. :)  I know it's seeing the configuration section correctly because
it honors the NoLogo option, and both options show up in the X server's log.

There is something funny going on with aspect ratios and/or scaling.  Most
of the ATSC programming here is really 4:3 presented in 16:9 format with
black bars on the sides.  When I display this on the normal VGA monitor in
default 16:9 mode I see it letter boxed as expected such that the 4:3 image
is centered with black bars on all four sides.  If I use the W command to
select 16:9 Zoom mode I get approximately the right result with the 4:3
picture full-screen.

When I display in default 16:9 format on the TV I see the 4:3 image against
the right side side of the screen with black on the left, top, and bottom.
(In spite of this, selecting 16:9 Zoom mode again does the right thing.)  If
I had real 16:9 material I think I would be missing a chunk on the right.
Thoughts?  Of course, none of this matters much if I can't get rid of the
motion artifacts...

				Dan Lanciani
				ddl at danlan.*com

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