[Mplayer-dev-eng] x11 vs. dga

[Andreas Ackermann (Acki)]

Hi Folks,

some words on DGA driver:

I know I haven't been doing a lot for it recently, but I'm still following
the discussion and I definitely want to keep working on it, but life
sometimes is more than Linux ;-)

It's right, the numbers shown by mplayer are not the end of all wisdom.
Simply hook a terminal to a serial line, run top and you'll see what is
going on in your system (i.e. what X11 is doing). You'll notice a big
difference between -vo X11 and -vo DGA ...

Generally spoken, I think there is a lot of developpment in XFree at the
moment and maybe things are definitely faster in XFree 4.0 than in XFree
3...

Technically spoken, there is a way to do it twice as fast as with DGA and
X11 *might* do it this way:

DGA copies values from one memory location to the other; so data has to
travel from memory via bus to CPU and then via bus to framebuffer memory;

If the X11 driver somehow makes the graphics card fetch the image data in
its memory by using DMA then busbandwith is only half of what it is in the
above example; the CPU would be idle in this case or just slowed donw when  
waiting for bus access ... but I don't know how it is done.

I guess if one also considers the time of the X11 process DGA and X11 are
equal and depending on the server module controlling your card DGA might
also be better ... 

Greetings

-Andreas
-------------------------------------------------------------------
        http://www.acki-netz.de  email: acki at acki-netz.de 
   //   (+49)[0]9131/409500 or (+49)[0]9286/6399
 \X/    acki or acki2 on #rommelwood

   No trees were killed in the sending of this message. However 
     a large number of electrons were terribly inconvenienced.



_______________________________________________
Mplayer-dev-eng mailing list
Mplayer-dev-eng at lists.sourceforge.net
http://lists.sourceforge.net/lists/listinfo/mplayer-dev-eng