[XviD-devel] question about image color space

[MAILER-DAEMON]

I had few quick question about image color space in ver1.1.0-beta1.

For images with alpha values(XVID_CSP_BGRA, XVID_CSP_ABGR, XVID_CSP_RGBA,
XVID_CSP_ARGB) how is alpha treated?

What I mean by that is, while RGB is transformed to YUV then U and V  
downsampled. And the motion vector used for Y is used for U and V.
What about alpha? My guess is that it is not downsampled and uses the
same motion vector for Y.
I'd appreciate it if someone can confrim this.

Also I'd like to add the following color space values.
- RGBA : planar
- RGB  : 24-bit rgb packed(I only see BGR)
- Y    : 8-bit greyscale(see my previous post)

I was wondering if any of the previous modes are to be planned in the 
future. If not I'd appreciate if someone could point me to where I can
find verification code if there is any.