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

[Alban Bedel]

On Wed, 13 Feb 2008 13:46:14 +0100
Michael Niedermayer <michaelni at gmx.at> wrote:

> On Tue, Feb 12, 2008 at 11:32:56PM -0500, Rich Felker wrote:
> [...]
> > 
> > > Iam not saying that there is any need or sense to store this nor
> > > that i would know what a decoder would do with that information,
> > > but i do know copper purity counters will prefer NUT over other
> > > formats if the distance is stored.
> > 
> > Well I would like to see some mathematical/physical reason that it's
> > potentially useful rather than the opinions of people who pay for
> > solid-gold *digital* audio cables to give their sound "more body"...
> 
> Id say liquid he cooled superconductive cables are better (for
> digital of course).
> 
> Anyway, technical reason:
> If the player knows the reference locations and actual locations it
> can adjust the delays to avoid unwanted interference. And no i dont
> know how well it would work in practice.

I think the pb is that the best interpretation (ie. absolute in real
world units or relative) depend on how the sound was mastered.

If you take todays movies and albums you probably want a relative
interpretation, so that most speakers just get the unadultered sound.

On the other hand if someone is doing a recording which is supposed to
be heard on a well defined setup, and one want to get the closest
possible experience to what was intended, real world units are needed.
But I suspect even more is needed for a really good simulation. The
echo characteritic of the room, temperature, wind, etc

So perhaps we should just have relative coordinate for now, and add a
note that we are open to add a standard info packet for "listening
environement simulation" if ppl from this field are intersted.

> Though with extreem cases like 1km difference it could correct the
> resulting A/V desync at least.

:)

> > 
> > > > Otherwise I don't see
> > > > anything wrong.
> > > 
> > > good, what about the flag to skip the stuff = unknown pos? Do we
> > > want one if not what should be muxer store if it doesnt know the
> > > pos?
> > 
> > I suspect skipping pos should not be legal for >2 channels..
> > For 2 channels or fewer, making it optional would be nice.
> 
> I dont think its too usefull for 2 ch, a default of (-1,0,0) (1,0,0)
> would be easy for the muxer to store. And similar for 1 ch ...
> But if a muxer has to store 5ch audio, figuring out the channel
> placement could be trickier. Iam not saying iam against it, actually
> maybe it is the correct thing to do, and having this optional would
> just lead to it being missing most of the time ...

I agree, making it mendatory is the best option. But them we should
perhaps define some defaults for typical configurations.

	Albeu