For a small video editing application I'd like to read back the contents 
of my OpenGL window to a AVI file. The process is not the problem, just 
the speed of glReadPixles. Does anybody know a faster method of access 
to the framebuffer contents. It is not neccessary that it uses OpenGL 
functions for readback, but it should be able to access the contents of 
the framebuffer and be faster then glReadPixels. The rendering window is 
ensured to be visible all the time and won't be obscured, so clipping is 
no problem.

-- 
+------------------------------------------------+
| +----------------+ WOLFGANG DRAXINGER          |
| | ,-.   DARKSTAR | lead programmer             |
| |(   ) +---------+ wdraxinger@darkstargames.de |
| | `-' / GAMES /                                |
| +----+''''''''     http://www.darkstargames.de |
+------------------------------------------------+

JB West wrote:
> After a lot of looking, I've found that with the latest drivers, with the
> optimal
> readback format, which varys from card to card, (USually BRGA, unsigned
> byte) is faster than anything else:
> about 40 Megapixels/sec (~frames/sec).

So you suggest to try out all avaliabe readback formats and see how they 
perform? Well, this is gonna to be a looong night... Not for me, but my 
computer.

-- 
+------------------------------------------------+
| +----------------+ WOLFGANG DRAXINGER          |
| | ,-.   DARKSTAR | lead programmer             |
| |(   ) +---------+ wdraxinger@darkstargames.de |
| | `-' / GAMES /                                |
| +----+''''''''     http://www.darkstargames.de |
+------------------------------------------------+

Wolfgang Draxinger wrote:

> For a small video editing application I'd like to read back the
> contents of my OpenGL window to a AVI file. The process is not the

Take a look at the demo posted here:
http://www.delphi3d.net/forums/viewtopic.php?t=176
It uses GDI calls instead of glReadPixels.

-- 

Sebastian Schuberth

Sebastian Schuberth wrote:
> Wolfgang Draxinger wrote:
> 
> 
>>For a small video editing application I'd like to read back the
>>contents of my OpenGL window to a AVI file. The process is not the
> 
> 
> Take a look at the demo posted here:
> http://www.delphi3d.net/forums/viewtopic.php?t=176
> It uses GDI calls instead of glReadPixels.

Do you also know something about X11? I'm working under Linux.

-- 
+------------------------------------------------+
| +----------------+ WOLFGANG DRAXINGER          |
| | ,-.   DARKSTAR | lead programmer             |
| |(   ) +---------+ wdraxinger@darkstargames.de |
| | `-' / GAMES /                                |
| +----+''''''''     http://www.darkstargames.de |
+------------------------------------------------+

GDI and X11 are slower than glReadPixels these days, at least on NVIDIA.
ATI, as I recall, has pretty good glReadPixels performance.

"Sebastian Schuberth" <s.schuberth@tu-bs.de> wrote in message
news:bf4f4r$ao9un$1@ID-44097.news.uni-berlin.de...
> Wolfgang Draxinger wrote:
>
> > For a small video editing application I'd like to read back the
> > contents of my OpenGL window to a AVI file. The process is not the
>
> Take a look at the demo posted here:
> http://www.delphi3d.net/forums/viewtopic.php?t=176
> It uses GDI calls instead of glReadPixels.
>
> -- 
>
> Sebastian Schuberth
>
>