[XviD-devel] XVID_CSP_RGBA alpha unfilled?

[Christoph Nägeli]

Hi,

On 28 Aug, 2004, at 19:08, Sebestyén Gábor wrote:
> I recently noticed when decoding in RGBA mode xvidcore-1.0.1 it does 
> not set alpha layer so my movie plays in full dark.
> When I set all alpha components to 0xFF I can see my movie..
>
> Is it a bug or a feature?

I hope someone corrects me if I'm talking nonsense...
Here some thoughts from my part.

I think alpha shouldn't be set by xvid because the internal format is 
not RGB and I don't think an alpha channel can be encoded in the mpeg4 
stream. Though it's important to use an 32-bit colorspace because every 
pixel is word aligned which gives more performance.


i.e. I would set the alpha channel of your movie yourself and as a last 
thought, assuming it would be a bug, then there will be quite some time 
until there's altivec support for the new one. I'm running out of time 
before examen and the qpel routines aren't finished, too.


--
Regards
Christoph