[PLUG] NVIDIA and HDTV as monitor...

Dale Snell ddsnell at frontier.com
Sun May 22 22:42:30 UTC 2011


On Sat, 21 May 2011 19:25:03 -0700
someone <plug_1 at robinson-west.com> wrote:

> Turns out under XP that the video driver has a special tool to
> fine tune the resolution so that the picture fits the screen.
> XP Home 32 bit is not going to work with MythTV let alone a
> dual core Atom.
> 
> How under Linux do I fine tune the resolution in X?


There is an old X application, xvidtune, that can help.  It's
still available, as part of the xorg packages.  I used it a LOT
in the old days when I had to create my own mode lines for the X
config file.  (Boy am I glad I don't have to do that anymore!)
There are a few HOW-TOs out there (Google should find them,
probably at the Linux Documentation Project), plus the man pages
for xvidtune(1) and xorg.conf(5).  It's been a long time since I
messed with building my own mode lines, so my memory is a bit
hazy, but here's a little info, for what it's worth.

Running xvidtune without any options will pop up a small gui that
allows you to modify the scan mode on the fly.  It will also pop
up a small window warning you that you can destroy your monitor
with a badly-chosen mode line.  I don't know that modern LCD
displays are prone to that, but CRTs certainly were.  You Have
Been Warned.  The gui allows you to move the display up, down,
left, and right, as well as adjust horizontal and vertical size.
The "prev" and "next" buttons allow you to step through the
various modes, but I believe you have to have them specified in
the xorg.conf file before xvidtune can use them.  The gui will
also show you the pixel clock frequency in MHz, and the horizontal
and vertical sync rates, in kHz and Hz, respectively.

Using the -show option will print out your current mode line,
without the gui.  As an example, here's mine:

$ xvidtune -show
"2048x1152"   156.75   2048 2096 2128 2208   1152 1155 1160 1185 +hsync -vsync

The various fields of this mode line are:
"2048x1152" -- name of the mode
156.75 -- the dot (pixel) clock frequency, in MHz
2048 -- width of the display, in dot clocks
2096 -- horizontal sync start time, in dot clocks
2128 -- horizontal sync end time, in dot clocks
2208 -- total horizontal scan time, in dot clocks
1152 -- height of the display, in scan lines
1155 -- vertical sync start time, in scan lines
1160 -- vertical sync end time, in scan lines
1185 -- total vertical scan time, in scan lines
+hsync and -vsync are the polarities of the horizontal and
vertical sync signals.

It is also possible to specify various flags, such as "Interlace",
at the end of the line.  See the MONITORS section of the
xorg.conf(5) man page.  I found a calculator to be very useful
when working with this stuff.  :-)  Once you've determined which
mode lines you need, put them in the xorg.conf file, and restart
X.  Be sure you back up your original xorg.conf file!

Anyway, I hope this helps.

--Dale

--
"No plan survives first contact with the enemy."
  -- Helmuth Karl Bernhard Graf von Moltke



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