Remote desktop capture

[Carsten Haitzler (The Rasterman)]

On Mon, 07 May 2007 11:46:56 -0700 Eric Anholt <eric at anholt.net> babbled:

> On Mon, 2007-05-07 at 12:09 +0200, eberrocal at laurel.datsi.fi.upm.es
> wrote:
> > Hi to everybody, this is the first time that I write to this mailing list.
> > Sorry if my English is not very well.
> > 
> > I have been searching information but I do not find anything about this. I
> > pretend to execute 3D applications (OpenGL applications) in a remote X
> > session (normally in a power 3D cluster) and watch the result in my local
> > (normally poor) machine.
> > 
> > One of the solutions that I have thought to transport the rendered data
> > are video. There are a lot of applications allow me to capture the openGL
> > buffer, compress it in a video frame and make a video with this video
> > frames (or send this video thought the network with vlc for example) like
> > yukon, recordMyDesktop, etc.
> > 
> > visit  http://linuxmafia.com/faq/Apps/desktop-video-capture.html
> > 
> > Via ssh the user open a X session with the command:
> > 
> > user at node0:~$ startx -- :1 &
> > user at node0:~$ export DISPLAY=:1
> > 
> > in the remote machine, and now I can execute any openGl application like
> > 
> > user at node0:~$ glxgears
> > 
> > The problem comes when I pretend to capture the window of the openGL
> > applications or the entire desktop where this application is running. The
> > result is a video where the openGL application zone is absolutely black,
> > there are nothing to capture.
> > 
> > I do not know if I can do this in a different way or if It is impossible.
> > I suspect that the problem is clipping, because this X session is not been
> > displaying in a monitor and possibly the clipping algorithm fail for the
> > entire openGL zone.
> 
> Until semi-recent Mesa from git plus xserver 1.2, direct-rendering
> OpenGL applications wouldn't cause damage events to be posted, resulting
> in smart screen-capture programs not picking up the updates.
> 
> Not sure if this is the problem you're seeing, though.

it's probably opengl using an overlay :) (ala xv). some peculiar gl
implementations/cards use overlays... in which case you're "out of luck". :(

> -- 
> Eric Anholt                             anholt at FreeBSD.org
> eric at anholt.net                         eric.anholt at intel.com
> 
> 


-- 
------------- Codito, ergo sum - "I code, therefore I am" --------------
The Rasterman (Carsten Haitzler)    raster at rasterman.com
裸好多
Tokyo, Japan (東京 日本)