[XviD-devel] MPEG4 compliance and the Xvid codec

[Edouard Gomez]

Arvind Raman (arvind_raman at yahoo.com) wrote:
> I read at quite a few places (besides the XviD FAQ)
> that Xvid is an ISO/IEC MPEG4 compliant video codec.

That's the project purpose.

> I was just wondering if it would be safe to assume
> that any MPEG-4 compliant video decoder would be able
> to decode any stream generated by the Xvid encoder.

This depends on the decoder profile.

XviD 0.9.x is a Simple Profile encoder, so every decoder which supports
Simple Profile features is able to decode its streams.

The Xvid fomr HEAD and dev-api-4 branches are Advanced Simple Profile,
so you have to use an ASP decoder to be able to decode all its streams.

> What  I  was   just  wondering  was  whether  Xvid   has  an  optional
> non-compliant  mode, in  which it  would digress  from what  the MPEG4
> standard specifies (If I am not wrong DivX works this way).

No  we don't  have  a  special mode  in  which XviD  would  be non  spec
compliant. The only  cases where XviD is not compliant  are bugs in XviD
code  and they  are fixed  with  time and/or  eye balls  looking at  the
code. This happenned 3 or 4 times in the past.

-- 
Edouard Gomez