Re: [gentoo-user] Re: External monitor is stretched 4:3

[Mick]

On Saturday 01 Dec 2012 09:49:01 Nuno J. Silva wrote:
> On 2012-12-01, Grant wrote:
> >> >    I've connected my laptop to a lot of HDTV's and whenever I switch
> >> >    the output to display on both screens, black bars appear on the
> >> >    left and right of my laptop screen so it displays at 4:3, and the
> >> >    HDTV output is 16:9 but looks horizontally stretched.  Does
> >> >    anyone know how to keep the output at 16:9 on both screens?
> >> >
> >> >    - Grant
> >>
> >> You don't give a lot of information here. Are you using mirrored
> >> screen or an extended desktop? Also what is the desktop environment or
> >> window manager you use?
> >>
> >> On thing that might help is to provide the output of xrandr.
> >
> > I'm using xfce4, but I'm not sure if I'm using a mirrored screen or an
> > extended desktop.  All I do is plug the laptop into the HDTV with an HDMI
> > cable and hit the keyboard shortcut to switch screens which brings up a
> > little dialog.
>
> There is nothing too complex here, if the TV and laptop are showing the
> same thing, one screen is *mirroring* the other, otherwise, if you see
> different things in different screens, you're using an extended desktop.
>
> > I was able to change the resolution from 1024x768 to 1366x768 with
> > xfce4's Display settings, but when I disconnect and reconnect to the
> > HDTV it displays at 1024x768 again.  Do you know how to select the
> > output resolution for an external screen permanently?  Is this done in
> > xorg.conf?
>
> This is, I'd guess, a "preferred" video mode announced through EDID,
> where the TV, even if it supports 1366x768, will anounce 1024x768 as
> preferred. You could do the change with a small xrandr one-liner, and
> there must be some way to do it through xorg.conf, although I don't know
> how.
>
> In the end, having the output of xrandr (both before and after you
> change the video modes) would help *a lot*, as it answers most of our
> questions...

You can set this up either with xranrd entries in your ~/.xprofile or in your 
/etc/X11/xorg.conf

First run xrandr -q to see what you get from an xterminal and then manually 
alter the resolution according to your requirements on each screen, e.g.

xrandr --output DVI0 --mode 1366x768 --rate 60
xrandr --output LVDS1 --primary
xrandr --output TV1 --mode 1920x1080

etc. until you get things as you want them.

Look at your /var/log/Xorg.0.log to see what resolution and refresh rate your 
card can do, although xrandr -q will show this.  The refresh rate is not 
really required (I think it is automatically set to match the screen 
resolution).

You can if you prefer set it up in /etc/X11/xorg.conf:

Name your monitors in your Section "Device":
===========================================
Section "Device"
[snip ...]

        Identifier  "Card0"
        Driver      "radeon"
        BusID       "PCI:1:0:0"

        Option          "monitor-VGA" "my 2nd monitor"
        Option          "monitor-LVDS" "my laptop"
        Option         "monitor-TV1" "my TV"
EndSection
===========================================

Then set up the screen resolutions for each monitor:
===================================================
Section "Monitor"
        Identifier      "my 2nd monitor"
Option "PreferredMode"  "1024x768"
Option        "Position" "1024 0"
EndSection

Section "Monitor"
        Identifier      "my laptop"
Option "PreferredMode"  "1366x768"
Option        "LeftOf" "my 2nd monitor"
EndSection

[snip ...]
EndSection
===================================================

Then set up the default screen:
==============================
Section "Screen"
        Identifier "Screen0"
        Device     "Card0"
		Monitor "my laptop"
[snip ...]
==============================

The above is just a guide of course.  You can tweak it according to your 
requirements and see what gives.  For more permanent set ups I would tend to 
use xorg.conf (old habits die hard), but .xprofile may be quicker/easier to 
try out.
-- 
Regards,
Mick