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

Seth Daniel mythtv.org at sethdaniel.org
Thu Aug 23 19:47:35 UTC 2007

On Sun, Jul 29, 2007 at 03:48:58PM -0400, Doug Larrick wrote:
> Brian Foddy wrote:
> > On Sunday 29 July 2007, Tom Dexter wrote:
> >> Being one of the unfortunate MythTV users with a RPCRT (1080i) display,
> >> I've been around the block with the nVidia interlacing issues as discussed
> >> here:
> >>
> >> http://www.gossamer-threads.com/lists/mythtv/users/270200

Hey, I wrote that!  :o) 

> >> Has anyone seen any sign indicating that some day nVidia might address
> >> this? There have been several threads on the nVidia Linux forum over the
> >> years, and I've yet to see them acknowledge that there's even a problem.
> >>
> >> I've just ended up settling for enabling kernel deinterlacing and accepting
> >> it the way it is, but it really brings me down.  1080i content on my TV
> >> should be breath-taking, but instead I have to settle for it being inferior
> >> to 720p...not to mention deinterlacing doubles the CPU usage.
> >>
> >> Tom
> >>
> > 
> > Not sure I'd classify  myself as an "unfortunate" owner of a RPCRT 1080i
> > TV, but rather as being well seasoned with HDTV as both myself and parents
> > have similar 51" CRT RP TVs for many years now.  
> > 
> > But that aside, I find my picture is much better
> > if I set the TVs to 540p.  The display artifacts are much reduced 
> > (jagged edges), the TV actually thinks its a 1080i signal, and I can't 
> > really tell the visual  difference to live 1080i HDTV.  At least good enough
> > until I can afford a 1080p TV, then I'll really think the rest of the world is
> > "unfortunate" :).
> Seconded.  You really want a 1920x540p mode so you're not discarding
> horizontal resolution:
> http://www.mythtv.org/pipermail/mythtv-users/2004-July/049482.html
> That, coupled with bob deinterlacing, should give you as good a 1080i
> picture as you're able to get.

I don't know if it's the TV, the driver, or just my incompetence, but I
cannot get 1920x540 (the 540pw mode described in the above link) to
work.  My custom 1080i mode is:

  Mode "1080i"
    DotClock 74.25
    HTimings   1920 2008 2052 2200
    VTimings   1080 1084 1089 1124
    Flags      "Interlace" "+HSync" "+VSync"

For the 540pw mode I changed it to:

  Mode "540pw"
    DotClock   79.912
    HTimings   1920 2008 2052 2200
    VTimings   540   542  544  562
    Flags      "+HSync" "+VSync"

(I also tried the vtimings that were in the above link).

When I do this I get an enormous letter-boxing effect with the video being in
(approx) the middle 1/3 of the screen.  So a little strip of video with giant
black bars on the top and bottom.  The image should fill the entire screen.

Am I, once again, screwed?  Or have I not tried hard enough to get 540pw to

One other question regarding the "Different video resolutions for GUI and
playback".  In my xorg.conf I had this as my Modes line:

  Modes  "1280x720" "540pw"

When I go to the Setup screen that allows me to configure the different
resolutions I don't get one named "540pw".  I do get one that is named
"1920x540" which I presume is my custom modeline (is that a correct assumption?
What if there was a builtin resolution named 1920x540?  Does mine override it?
Would there be two 1920x540 resolutions to choose from?).  Also, it didn't seem
to matter which resolution I chose for the video playback.  It always jumped to
540pw (according to the Xorg.0.log) when I switched from the GUI to
playback...even when I told it to use 320x200 for playback.  That behavior was
unexpected to say the least.

I am running very recent SVN (14260).

seth / @sethdaniel.org
I used to work in a fire hydrant factory.  You couldn't park anywhere near
the place.

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