[mythtv-users] Re: pcHDTV with FX5200 TV-Out

Scott Alfter mythtv at salfter.dyndns.org
Wed Dec 8 00:54:57 UTC 2004

On Tue, Dec 07, 2004 at 02:41:14AM -0500, Dan Lanciani wrote:
> Jarod Wilson <jcw at wilsonet.com> wrote: 
> |Well, I just remembered I have two clips you can try out, one 1080i, one 720p,
> |both sitting around on my web server.
> |
> |1080i: http://wilsonet.com/mythtv/cbs-in-hd.nuv
> |720p: http://wilsonet.com/mythtv/abc-in-hd.nuv
> |
> |Both are in the 100MB or so range, less than a minute each, but should be
> |suitable for testing.
> Ok, I finally got back to this. :)  Recall that the question was about
> how real 16:9 material displayed on my TV-Out.  Although I was pretty
> sure it was wrong, the signals I was viewing were really 4:3 with side
> bars to fill out to 16:9 so I wasn't 100% sure.  I downloaded your ABC
> clip, but it also seems to be 4:3 with side bars!  Worse, it plays with
> a horrible slow-motion stutter.  Recordings I make locally play ok.  This
> is still the 3.2GHz P4.

mplayer says both clips are 16:9, with the CBS clip at 1920x1080 and the ABC
clip at 1280x720 (why they sideboxed 4:3 content is anybody's guess).  I'm
playing them both on an Athlon XP 2400+ to a 30" LCD at 1280x768.  The
monitor is driven by the DVI output of a generic GeForce FX5200.

The ABC clip plays OK (aside from being a box centered in the middle of the
screen and from apparently being scaled to use only about two-thirds of the
screen height).  The CBS clip plays OK if it's not scaled to fit within the
screen, but if it's scaled, horizontal motion has some nasty artifacts.  I'm
not sure if that's the result of scaling interlaced video or if it's a speed

I could come up with a 1080i modeline and drive the monitor with that. 
The CBS clip might then display properly.  However, 1280x768 is the panel's
native resolution and I'd rather keep it set there.

I think XvMC has been mentioned as a way to keep CPU usage down.  When I
tell mplayer to use it, though, it refuses to do so.  Is there some
checklist somewhere of things to do to make sure XvMC will work and will be
available to MythTV and mplayer?

(I don't yet have a HD video source other than the two sample clips that I
downloaded a while back (they appear to have since been taken down), but I
figured I'd make sure everything's working right first.)

One more question: is there something that will convert MPEG-2 transport
streams to program streams?  I currently copy SD video captured by a PVR-350
to a Windows box for editing and DVD authoring.  I'd like to eventually do
the same with HD video (it'll obviously need resampling to 720x480 to fit
within the DVD-Video spec), but my usual tools (TMPGEnc, DVD2AVI, etc.)
appear to choke on transport streams.  What software (either for Linux or
Windows; it doesn't matter to me) will work to decode HD MPEG-2 transport
streams so they can be edited?

 / v \ Scott Alfter 
(IIGS( http://alfter.us/            Top-posting!
 \_^_/ rm -rf /bin/laden            >What's the most annoying thing on Usenet?

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