Enable black borders on widescreen display

[Matthias B.]

On Sat, 26 Jan 2008 13:43:51 +0100 Dustin Lange <dlange.mail at sent.com>
wrote:

> But how can I convince xrandr to display the black borders and not to 
> stretch the image on the widescreen display?

I had a similar problem. My LCD TV has a resolution of 1360x768 but
8 columns and 7 rows are hidden by the case, so I needed a video mode
that is 1352x761 on the Xorg side (so that Xorg won't use more than this),
but still 1360x768 on the monitor side (so that the monitor doesn't
scale). I solved this by adding a Modeline 1352x761 to my Monitor section
that is identical to the 1360x768 mode (that the monitor reports via DDC)
except for the horizontal and vertical total number.

So I suggest you take the timings for your LCD panel's native mode, copy
them to a ModeLine in the respective monitor section and then reduce the
horizontal and vertical total to 1024 and 768 respectively. When tell Xorg
to use that mode for your LCD panel, it will see it as a 1024x768 mode,
whereas the panel will treat it as its native resolution and won't scale.

That said, I don't see why you would need such hacks. There's no need for
2 cloned displays to have the same resolution. In my dual-head setup I
have aforementioned LCD TV and a 1280x1024 LCD monitor. I run a
virtual size of 1352x1024 and each screen displays a part of that screen
that corresponds to its natural dimensions (no scaling). So when I move
the mouse cursor too far right, my LCD monitor's view scrolls
horizontally, whereas my TV view stays put (since it can display the
complete horizontal resolution). When I move my mouse cursor too far down,
my TV view starts scrolling to keep the mouse in view, whereas my LCD
monitor doesn't (since it can display the complete vertical range).

MSB

-- 
An army of sheep led by a lion
is stronger than an army of lions
led by a sheep.