[mythtv-users] strange 1920x540 with nvidia

[Seth Daniel]

On Mon, Feb 19, 2007 at 06:12:13PM -0800, Marco Nelissen wrote:
> >The problem is that when I select the 1920x1080 mode I get only a
> >'virtual' screen of 1920x1080 (the nvidia driver calls this the
> >'backend' resolution).  I get a visible screen (frontend) of 1920x540.
> >Everything is chopped off in the middle (video playback is chopped in
> >the middle, the mythtv frontend is chopped in the middle, etc...).
> >This is with the 9xxx nvidia drivers.  
> 
> I have the same problem with the latest drivers and a Sharp Aquos LCD.
> After noticing in Xorg.0.log that the resolution it picked had a 120Hz
> refresh rate, and further finding that the driver seemed to completely
> ignore any refresh rate limits I put in xorg.conf, I ended up modifying
> mythtv locally to reject any refresh rate that was significantly larger
> than standard TV refresh rates.
> There were other symptoms as well:
> - even though the main menu runs in 1920x1080i, first viewing of a 1080i
>   recording results in the image being "squished" vertically. I have to
>   play a 720p show first, after which 1080i will work.
> - after watching a 720p recording, the screen won't switch back to 1080i.
>   I mapped a button on my remote to run the appropriate xrandr command
>   to switch back to 1080i (a workaround which strangely does not work with
>   problem #1)
> For whatever reason I can't get the 8xxx drivers to work anymore, so I'm
> stuck with the 9xxx driver, but I'd advise anyone who has a 8xxx driver
> working to just stick with it, and not upgrade to any 9xxx driver.
> (though I'm sure someone will chime in to say that 9xxx works just dandy
> for them)


I have solved *one* of my two problems.  I am using the 1.0.9631 driver.

The problem I solved is that I have been able to get a true 1080i screen
on my TV.  I still have the problem that mplayer and myth show a black
screen when trying to play video, my Xorg.0.log file has a whole bunch
of "(WW) NVIDIA(0): WAIT(...)' messages and my computer goes into a
death spiral.  Eventually the computer simply turns off.

I know I tried something like this earlier and I had no success.
Tonight I read the following at a site I had previously never heard of
(but which is mentioned in the Nvidia driver README file) called
nvnews.net.  Here is the thread:

http://www.nvnews.net/vbulletin/showthread.php?t=69255

Here is the relevant bit of my xorg.conf:


##############################################################

Section "Monitor"
  Identifier   "Generic Monitor"

  Mode "1080i"
    DotClock   74.25
    HTimings   1920 2008 2052 2200
#    VTimings   540 542  547  562
     VTimings  1080 1084 1094 1124
    Flags      "Interlace" "+HSync" "+VSync"
  EndMode

EndSection

Section "Screen"
  Identifier    "Default Screen"
  Device        "NVIDIA Corporation NV40 [GeForce 6200TC]"
  Monitor       "Generic Monitor"

  Option         "RenderAccel"    "true"
  Option         "NoLogo"         "true"
  Option         "DPI"            "100x100"
  Option         "ModeValidation" "NoVertRefreshCheck,AllowInterlacedModes,AllowNon60HzDFPModes,NoEdidMaxPClkCheck"
  Option         "UseEvents"      "true"
  DefaultDepth  24
  SubSection    "Display"
    Viewport     0 0
    Depth        24
    Modes       "1080i"
  EndSubSection
EndSection

##############################################################


This allows me to run at 1920x1080i with the 9xxx series nvidia driver.
Essentially what I did was create my own modeline.  To create the
modeline I looked at the EDID output for 1920x1080 and used the same
dotclock and the same horizontal timings.  For vertical timings I simply
doubled everything.  I used the same flags as specified in the EDID
output.

The only ModeValidation option that was *required* to get true 1080i was
the 'NoVertRefreshCheck'.  Without that it went back to 1920x540.

I hope this helps someone.  I also hope someone knows how to solve my
other problem. :o)


-- 
seth / @sethdaniel.org
Q:  What's the difference between a Mac and an Etch-a-Sketch?
A:  You don't have to shake the Mac to clear the screen.