EGL_MESA_screen_surface proposal

Jon Smirl jonsmirl at gmail.com
Wed Mar 16 13:35:47 PST 2005


On Wed, 16 Mar 2005 15:10:24 -0500, Michel Danzer <mdanzer at ati.com> wrote:
> On Wed, 2005-03-16 at 15:04 -0500, Jon Smirl wrote:
> > On Wed, 16 Mar 2005 14:49:40 -0500, Michel Danzer <mdanzer at ati.com> wrote:
> > > On Wed, 2005-03-16 at 14:17 -0500, Jon Smirl wrote:
> > > >
> > > > The only reason you need the interlace attribute is when you have both
> > > > 1080p and 1080i available and you want to force 1080i. But now that
> > > > think about it I don't think you'll ever want to do this so we don't
> > > > need the attribute. I can't think of a situation where you want to
> > > > force an inferior mode when you have a better one available.
> > >
> > > Someone might want to play back interlaced video and not have to deal
> > > with de-interlacing.
> >
> > How does interlaced video playback work? Is there a way to have two
> > different surfaces and tell the hardware to switch on each frame?
> >
> > There are two ways to implement 1080i...
> > single 1920x1080 buffer that is scaning out alternate lines in each frame
> > two 1920x540 buffers alternating on each frame
> 
> These are implementation details and outside of the scope of this
> discussion I think. The point is that there are valid reasons for
> preferring an interlaced mode over a progressive one.

I think that info is quite critical. If you set 1080i you're going to
need two surfaces in the alternating buffer model.

Just because you have 1080i input doesn't mean that it can't be
scanned out at 1080p.

> 
> --
> Michel Danzer, Linux Software Engineering       \   Tel: +1 905-882-2600
> ATI Technologies Inc., Markham, Ontario, Canada  \       Extension: 3550
> 
> 


-- 
Jon Smirl
jonsmirl at gmail.com


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