Mark Vojkovich ([EMAIL PROTECTED]):
> > I noticed nasty tearing when using my DVD player + XVideo. This is
> > in contrast to the i810 driver which will wait to blit if called
> > during the retrace. My code now spins on the VGA port, which fixed
> > the tearing.
>
> No, that's not what happens. The MGA driver doesn't double buffer
> video so you get tearing. The i810 driver does so you don't. I doubt
> spinning on the client side can do anything to prevent tearing.
But if it double buffered it would still need to flip-on-retrace.
So you're saying that my spinning on the client is just making the
video not suck by coincidence?
> I think you misunderstand what the i810 driver is doing. [...]
Thanks for the clarification.
> > Do other drivers spin on a call to XvPut if the refresh is occuring?
>
> No. If you send faster than the retrace on NVIDIA hardware I just let
> it shear because I don't want the X-server eating CPU. Below the
> refresh rate, it won't shear.
So, if I'm running my display at 59.94hz and sending it NTSC video,
there's no way for me to get in sync without having some way of querying
the refresh, yeah?
> > Also, I wait for the refresh using something like this code:
> >
> > void spin_until_refresh_complete( void ) {
> > for(;;) if( inb( 0x3da ) & 8 ) break;
> > }
> >
> > Does anyone know what VGA cards this could fail on? So far it's
> > worked great for my i815, G400, and TNT2.
>
> It won't necessarily work on those. It depends whether or not I/O
> access is enabled. In the case of secondary cards, port access to
> legacy VGA registers is typically disabled.
Ok, what do you mean by this? Is this a software or hardware setting
or what?
On startup I run: ioperm( 0x3da, 1, 1 ), and I also require root
access.
--
Billy Biggs
[EMAIL PROTECTED]
_______________________________________________
Xpert mailing list
[EMAIL PROTECTED]
http://XFree86.Org/mailman/listinfo/xpert
