[FFmpeg-user] ffmpeg screencapture from a virtual xserver larger than the physical screen

Moritz Barsnick barsnick at gmx.net
Thu Nov 19 15:33:03 CET 2015

On Thu, Nov 19, 2015 at 15:14:31 +0100, Zenny wrote:
> Xpra works fine, but the bottleneck is that xpra downgrade the
> resolution of virtual X server also to match that of the client, which
> I do not want. See detailed discussion 'the xpra way' and her
> bottlneck at http://xpra.org/trac/ticket/1036

Is that an xpra or an Xvfb issue? If xpra just connects and forwards to
original Xvfb screen, and you connect to that screen (which you seem to
according to the ticket and your ffmpeg command line with ":99"),
x11grab should be seeing the original X session, regards of what xpra
is or is not capable of displaying or refreshing. OTOH, if the X server
(Xvfb) fails to refresh while xpra is connected, that problem will be
reflected in your captured session of course.

I know, I should have read up on xpra before claiming things. I do know
how RDP, VNC, x0vncserver and NX work though... ;-)

I really don't understand whether "xpra downgrades" means it actually
resizes the screen down to what it can accomodate, or whether it scales
down. In the latter case, it shouldn't matter, because you can still
capture the original. (Are you using "xpra shadow"?)

(Sorry if this doesn't help at all.)

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