[NUT-devel] [nut]: r613 - docs/nutissues.txt

[Michael Niedermayer]

On Tue, Feb 12, 2008 at 05:47:13PM +0100, Alban Bedel wrote:
> On Tue, 12 Feb 2008 16:00:10 +0100 (CET)
> michael <subversion at mplayerhq.hu> wrote:
> 
> > Modified: docs/nutissues.txt
> > ==============================================================================
> > --- docs/nutissues.txt	(original)
> > +++ docs/nutissues.txt	Tue Feb 12 16:00:09 2008
> > @@ -162,3 +162,8 @@ How do we identify the interleaving
> >  A. fourcc
> >  B. extradata
> 
> I would vote for this with a single fourcc for pcm and a single fourcc
> for raw video. Having infos about the data format packed in the fourcc
> is ugly and useless. That just lead to inflexible lookup tables and the
> like. 

> Instead we should just define the format in a way similar to what
> mp_image provide for video (colorspace, packed or not, shift used for
> the subsampled planes, etc). That would allow implementations simply
> supporting all definable format, instead of a selection of what happened
> to be commonly used formats at the time the implementation was written.

The key points here are that
* colorspace/shift for subsampled planes, etc is not specific to RAW, its
  more like sample_rate or width/height
* non raw codecs have clearly defined global headers (sometimes at least)
-> thus we cant really use extradata for it
   extradata would only be ok for things we definitly dont ever need for non
   raw


> 
> >  C. New field in the stream header
> > +D. Only allow 1 standard interleaving
> > +
> > +What about the interleaving of non raw codecs, do all specify the
> > +interleaving, or does any leave it to the container? If so, our
> > options +would be down to only C.
> 
> On a related subject, it might also be useful to define the channel
> disposition when there is more than one. Mono and stereo can go by with
> the classical default, but as soon as there is more channels it is
> really unclear. And imho such info could still be usefull with 1 or 2
> channels. Something like the position of each channel in polar
> coordinate (2D or 3D?) should be enouth.

I agree
What about that LFE channel thing? And where do we put this
info, The stream header seems the logic place if you ask me ...

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Democracy is the form of government in which you can choose your dictator
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