unity-design team mailing list archive

[Frederik Nnaji <frederik.nnaji@xxxxxxxxx>]

2010/5/12 Martín Soto <donsoto@xxxxxxxxx>

> If you want to activate it, though, it's as easy as changing the
> flat-volumes setting in /etc/pulse/daemon.conf to "yes".
>

thank you ;)


> Ensuring the alert sounds are loud enough to be heard over other sounds
>> - -- whether by making them temporarily louder, or making the other sounds
>> temporarily softer -- is an interesting idea, but it seems out of scope
>> for the sound menu itself.
>>
>
can be handled automatically by "side-chaining".
does pulse know side-chaining?

My idea to implement this, by the way, would be to measure the perceptual
> loudness [3] of the current stream using Replay Gain [4] or similar. The
> resulting (instant) value would be used to set the volume for the
> notification stream. This can probably be all done inside PulseAudio by
> creating an appropriate module.
>

i wouldn't want main volume to change automatically..
this is a very individual thing that should be left to the user's individual
preference/control..

Since I'm not an expert in signal processing, however, I don't know how
> difficult it would be to implement Replay Gain or a similar loudness measure
> in a way that can be used for this purpose. I also wonder what the impact on
> battery life would be. I'll try to look a bit more into these issues and
> report here when/if I find some answers. Of course, any useful pointers will
> be greatly appreciated.
>

you can't handle streams efficiently with Replay Gain.
Normalizing means the entire file has to be read first and scanned for
transients..

Altering the dynamics of digital audio information would alter the
information or message itself.. if you want to do this for flashmovies or
the like, report the bug to Adobe.
you can't just simply alter the dynamics of a sound creation, without
altering the actual message the respective sound is trying to convey..
dynamics are a major part of the semantics of sound.

normalizing a 3min audiofile takes quite a lot of CPU power and therefore
doesn't make sense at this point in this context.
and yes: of course this kind of cpu load would shorten battery life, if
constantly applied to files and streams when played..