[Pkg-freevo-maint] Bug#528431: multiseat configuration, Xephyr

[Daniel Pocock]

I've found some documentation on building `multiseat' X configurations:
- this seems to be like solution 1 above
- instead of splitting xorg.conf into two files, many of them recommend 
having two ServerLayout sections
- starting two X processes with the -layout parameter (to choose each 
ServerLayout) and also -novtswitch -sharevts

However, multiseat with xorg seems to be impossible with a dual-head 
card, because the two separate X processes can't share the same hardware 
(even for getting at the two separate output ports).  Ultimately, to 
make this work with current drivers, it seems that a single X process 
needs to have the ability to operate independent displays, :0 and :1, 
from a single process, but that is not possible either at present.

There is a workaround proposed by some of the multiseat documentation:
- tell gdm to start X, but not to handle :0
- tell gdm to start xephyr on :0.0 as :1 running a login screen
- tell gdm to start xephyr on :0.1 as :2 running freevo

I've tested xine under Xephyr and didn't observe any difference in CPU 
load or picture quality.  Does this seem like a reasonable way to run 
freevo as part of a multiseat environment?

The only drawback with this approach is that the main desktop is also 
going through Xephyr, and this might impact some apps.  For me, this is 
probably OK, as I use email, web and ssh, but for someone who wants to 
use games or 3D apps, I suspect this won't be a solution.