Xvfb and number of bytes per pixel

Adam Jackson ajax at nwnk.net
Fri Sep 11 19:10:07 UTC 2020


On Fri, 2020-09-11 at 00:04 +0200, Marcin K wrote:
> Thank you for explanation.
> That was my deepest fear. The main issue is that I'm copying the
> image data real-time, and in my case, on 4* UWXGA display, this one
> byte means 9MB less data per frame.  

I mean... yeah, half a gigabyte per second isn't trivial, sure. Though
if you're using the Damage extension you can avoid copying unchanged
areas of the screen, which should cut that down quite a bit.

Alternatively, Xvfb in current git has glamor support, at least on GBM
(non-NVIDIA) systems, which would mean with a bit of cleverness you
could just import your application's window as a buffer object and
texture straight from that without bothering with the host memory part
of the game.

Alternatively, you could always try building Xvfb from 1.19.x and see
if the 24bpp support works well enough for you. But that seems
suboptimal compared to getting glamor to work, if you can get glamor to
work.

If you can describe in a bit more detail what you're trying to do it
might help figure out what a good solution would be.

- ajax



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