[XviD-devel] XVID_CSP_RGBA alpha unfilled?

[Christoph Nägeli]

On 29 Aug, 2004, at 22:18, Kurt Bernhard Pruenner wrote:
> Christoph Nägeli wrote:
>> 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 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.
>
> I think what he meant was that when he wanted XviD to decode his movie
> to RGBA the result had all alpha values set to fully transparent, so he
> couldn't see anything. Of course there are no alpha values stored in a
> movie, but shouldn't the decoded images have all their alpha values set
> to fully opaque so you can actually see something?

Does the Alpha Channel gets overriden with transparent or is it left 
untouched?

--
Christoph