Arch Linux

anstmich

Member

Registered: 2009-06-20

Posts: 29

[SOLVED] Creating a Virtual Display/monitor

Hi all,

After quite a bit of searching, I have been unable to find a solution, so I thought I might raise the question here: 

Is it possible to create a configurable "virtual" display (which would be recognized like any real physical monitor by X/desktop environment)?  I have noticed in the past that if I have two monitors enabled through xrandr and then I suspend my computer, unplug one of the monitors, and unsuspend my computer, X can be tricked into thinking that the second monitor still exist (in xfce, the mouse can still be moved off of the screen into the region where the second monitor was previously).  While this behavior is generally undesirable, it could be quite useful if a virtual network client were attached to the virtual monitor to produce an addition monitor using another VNC-enabled device. 

Hopefully my explanation was clear; if not, let me know and I will elaborate further!

Regards,
A

Last edited by anstmich (2014-05-01 20:50:03)

anstmich

Member

Registered: 2009-06-20

Posts: 29

Re: [SOLVED] Creating a Virtual Display/monitor

I think I may have spoken too soon. I was able to create a "virtual" display by adding a new mode to one of the disconnected displays listed in xrandr using

xrandr --addmode VIRTUAL1 1024x768

I then simply enabled the display like you would normally:

xrandr --output VIRTUAL1 --mode 1024x768 --left-of HDMI3

Furthermore, combined with x11vnc -clip, I am able to use this to convert my android tablet to a second monitor.  The perfomrance is pretty crappy at the moment, unfortunately, but that's whole other area to be explored.

squiidux

Member

Registered: 2013-06-01

Posts: 19

Re: [SOLVED] Creating a Virtual Display/monitor

excellent! nice work.

Feadurn

Member

Registered: 2013-05-15

Posts: 15

Re: [SOLVED] Creating a Virtual Display/monitor

anstmich.

Is it possible to have the step-by-step explanations on how you are doing it. It is been a long time now I try to figure out how to use my tablet as a second monitor with my laptop on Arch (and when you say it is crap, is it good enough to work with it, no game or videos?)

Thank you very much.

mequ

Member

Registered: 2015-10-05

Posts: 1

Re: [SOLVED] Creating a Virtual Display/monitor

I think I may have spoken too soon. I was able to create a "virtual" display by adding a new mode to one of the disconnected displays listed in xrandr using

xrandr --addmode VIRTUAL1 1024x768

I then simply enabled the display like you would normally:

xrandr --output VIRTUAL1 --mode 1024x768 --left-of HDMI3

Furthermore, combined with x11vnc -clip, I am able to use this to convert my android tablet to a second monitor.  The perfomrance is pretty crappy at the moment, unfortunately, but that's whole other area to be explored.

can you put more data about how you add VIRTUAL1 to xrander all I see is :

# xrandr
HDMI1 disconnected (normal left inverted right x axis y axis)
DP1 disconnected (normal left inverted right x axis y axis)
HDMI2 disconnected (normal left inverted right x axis y axis)
HDMI3 disconnected (normal left inverted right x axis y axis)

and there is no VIRTUAL1 display .

blueyed

Member

Registered: 2015-09-19

Posts: 5

Re: [SOLVED] Creating a Virtual Display/monitor

@meku

> there is no VIRTUAL1 display

You can use any of the existing outputs, e.g. `DP1`.