[mythtv-users] Any hope for 1080i content at 1080i with nVidia?

Tom Dexter digitalaudiorock at hotmail.com
Mon Aug 27 18:46:37 UTC 2007

>From: Seth Daniel
>On Fri, Aug 24, 2007 at 11:29:46AM -0400, Tom Dexter wrote:
> > For the time being, I've settled on using 1080i output (with a custom 
> > line) and using Viktor's patch here:
> >
> > http://svn.mythtv.org/trac/ticket/2903
> >
> > ...to allow bob deinterlacing, and that made a huge difference...not as 
> > as it would look with the driver working correctly and no de-interlacing 
> > all, but very good.  By the way...someone on avsform.com noticed that 
> > line in that patch that reads:
> >
> > if (mode_line.flags && 0x010) // #define V_INTERLACE 0x010
> >
> > ...should actually be using s bitwise operator:
> >
> > if (mode_line.flags & 0x010) // #define V_INTERLACE 0x010
> >
> > ...otherwise it could it would be true if any flags at all happen to be 
> > in those flags (though it didn't cause me any problems before I changed
> > that).  I'm still baffled as to why mythtv reports a 60Hz refresh rate 
>as 30
> > if the output is interlaced, which is what that patch changes in order 
> > allow use of bob.
>Wow.  This actually seems to work.  I use a custom 1080i modeline, add
>the patch linked above (with the change mentioned directly above), and
>1080i actually works and looks good.
>Thank you to Tom and to Viktor.
You're welcome!...but Viktor deserves the credit for finding this one.

Looks great doesn't it?  After using it for a while I'm finding that my 
original impression of it as being the next best thing to not having to 
de-interlace at all, almost doesn't do it justice.  I did an interesting 
comparison the other night:

My mythfrontend is on a DVI switch box that lets me switch between it and my 
old Samsung SIR-T351 HD tuner.  During an NFL preseason game on NBC (1080i) 
I tried switching between the two...the mythfrontend with bob de-interlacing 
and the tuner which handles interlaced content properly.  Fast moving sports 
with all the panning etc at 1080i is a real acid test for this sort of 
stuff.  Honestly I could barely tell the difference.  In a blind test I 
might actually have picked the mythfrontend.  720p broadcasts actually are 
better on my myth system than the Samsung receiver as it does a better job 
of up-converting 720p->1080i than the Samsung (or my TV for that matter).


See what you’re getting into…before you go there 

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