OS/X11 support for XO-1 hardware?

Chris Marshall jns-cmarshall at comcast.net
Thu Feb 26 10:05:12 EST 2009

Benjamin M. Schwartz wrote:
> david at lang.hm wrote:
>>>  It would allow for much improved
>>> video performance since you could play back a 320x240
>>> video on the full screen at considerable CPU savings.
>> except that you would spend those CPU savings doing the scaling up from 
>> 320x240 to the higher resolution.
> Argh and double argh! You're both wrong.
> 1. Video playback in any sane player is already routed through XV, which
> uses the GPU's video overlay scaler (and YUV->RGB converter).  The result
> is that playing a 320x240 video at 1200x900 full-screen already costs zero
> extra CPU cycles.  No need to mess with screen resolution.
> 2. The Geode LX GPU can do both output scaling and video-overlay scaling,
> independently, at the same time.  On the latest drivers, we should be able
> to set the screen resolution to 600x450, scaled up to 1200x900, and then
> play a 320x240 video, scaled up to 480x360 (which means 960x720 physical
> LCD pixels), all without using any CPU power for scaling.
> There are lots of good reasons to play with screen resolution.  My
> favorite reason is that reducing the resolution to 800x600 would make all
> graphical operations runs twice as fast, and use half as much memory,
> while introducing a negligible drop in display quality (the display,
> remember, is not _really_ 1200x900 in color mode; the total number of
> color elements is equivalent to 800x450).

This last point is what I was hoping for.  From other discussions,
the X 1.4 driver now has scaling support.  What isn't there is a
release for the XO that has that driver in it.

I realize that since it is open source, I should be able to
put this in myself.  The reality is that I am too far down on
the X11+linux power curve to do this without significant time
and effort.  My hope is that someone who already knows how this
works (e.g. OLPC?) would get this working so I could make use
of it for application development and G1G1 usability features
such as WINE.


More information about the Devel mailing list