Single Board Computer for HD XVideo?

Carsten Haitzler (The Rasterman) raster at
Tue Jan 2 17:17:29 PST 2007

On Tue, 2 Jan 2007 19:37:15 +0200 Daniel Stone <daniel at> babbled:

> On Wed, Jan 03, 2007 at 01:49:39AM +0900, Carsten Haitzler wrote:
> > because i can't overlay and blend multiple videos at high resolution.
> Why would anyone want to do that?
> > "overlays" of osd's and underlays etc. won't be limited to yuv 422 etc.
> Er, you do know that the backing colourkey thing lets you do this
> without touching the video stream at all, right?  This is what
> colourkeys are _for_.

i don't WANT colorkeys. that's my point.

i want to be ABLE to do this:

i want my video just a normal drawable i can use - but it just happens to be in
yuv colorspace. color keys do not let me arbitrarily layer, "paste", blend,
overlay, etc. multiple yuv pixel sources. they let me either 1. boolean select
video or no video (traditionally), and in some slightly more advanced hardware
i might be able to provide an alpha mask plane for the 1 video overlay that
exists (and then no colorkey) with the fb contents blended by a certain amount
based on mask alpha value.

last i checked Xv couldn't do the above that I want. I am still waiting for it
to be able to:

1. DRAW video to any drawable (pixmaps included) from yuv pixel data (choose
your flavor) with scaling AND some given constant alpha value and/or an extra
provided alpha mask.
2. Do this with acceleration.

as of now my only choices are

1. xv to pixmap(xrender picture) then use xrender composite with transform for
scale and blend (but have only 1 part of that pipeline actually accelerated as
it sure as hell is not accelerated in both parts in my i845, nor on my nvidia
cards (5500fx, 6600gt, 7900gtx) and my r250 laptop is now in retirement so
that's a moot point (it's painful to think i have to get lucky with chipsets
just to possibly have it work).
2. use gl + fragment shader
3. software software software (do it all with the cpu - fine for standard def
if you don't have to do any scaling. death for 1080p...)

of the above - the gl solution always works - perfectly - as long as my card
supports glsl and non-power-of-2 textures (the 5500fx works but at continental
drift speeds with nv_rectangle textures). considering the cards you need are
now fairly old and readily found anywhere as addons - this is not a problem.
software also always works - everywhere, all the time, with no limitations
except speed (and that is entirely bound to cpu and bus speed).

i WISH that there was another option - but right now i see none before me.

> Cheers,
> Daniel

------------- Codito, ergo sum - "I code, therefore I am" --------------
The Rasterman (Carsten Haitzler)    raster at
Tokyo, Japan (東京 日本)

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