DirectDraw YUV overlays

[Matthew Mastracci]

I've been investigating the YUV overlays used by Picasa and it seems 
like it would be a huge problem to tackle this sort of support without 
some sort of external YUV conversion library and/or hardware support.

SDL has great support for transparent hardware/software YUV support; it 
might be possible to adopt some of the YUV hw/sw implementation code 
from SDL into Wine.  Both projects are LGPL.

Whatever the implementation, getting support into the DirectDraw layer 
for scaling YUV surfaces is a fairly large job.

Matt.

[Marcus Meissner]

On Sun, Mar 06, 2005 at 03:18:53PM -0700, Matthew Mastracci wrote:
> I've been investigating the YUV overlays used by Picasa and it seems 
> like it would be a huge problem to tackle this sort of support without 
> some sort of external YUV conversion library and/or hardware support.
>
> SDL has great support for transparent hardware/software YUV support; it 
> might be possible to adopt some of the YUV hw/sw implementation code 
> from SDL into Wine.  Both projects are LGPL.
>
> Whatever the implementation, getting support into the DirectDraw layer 
> for scaling YUV surfaces is a fairly large job.

We had that in very early versions (as ddraw was just one pretty
large X hack ;)

I would suggest using the Xv extensions again if possible.

Software YUV conversion is not hard either.

Just someone needs to do it :/

Ciao, Marcus

[Lionel Ulmer]

On Mon, Mar 07, 2005 at 01:09:34PM +0100, Marcus Meissner wrote:
> We had that in very early versions (as ddraw was just one pretty
> large X hack ;)

Those were the days :-)
> I would suggest using the Xv extensions again if possible.

Yes, and it will provide hardware-based scaling for free too... I wonder if
GL exports any YUV-like texture formats on modern hardware.
> Software YUV conversion is not hard either.

Yes, I have some code lying around that does it. Even wrote in in ARM
assembly for my iPAQ movie player :-)

      Lionel (back from vacation and catching up with his mails)

-- 
		 Lionel Ulmer - http://www.bbrox.org/

[Adam D. Moss]

Lionel Ulmer wrote:
> > I would suggest using the Xv extensions again if possible.
>
> Yes, and it will provide hardware-based scaling for free too... I wonder if
> GL exports any YUV-like texture formats on modern hardware.

Not really. :(  There's an apple-specific extension for it.  On
the other hand, YUV->RGB conversion should be really
easy to write as a fragment program (either NV_texture_shader,
ARB_fragment_shader [GLSL], ARB_fragment_program,
NV_fragment_program) on any gf3-era card or later, which I'm
guessing is why not many implementors are rushing to standardise
YUV textures.

--Adam