The Polypaudio sound server

Lennart Poettering mzkqt at
Thu Sep 9 16:12:45 EEST 2004

On Thu, 09.09.04 13:57, Mike Hearn (m.hearn at wrote:

> What does using this give people over JACK, which is the choice of pro 
> audio users? Why is it better than just raw ALSA with the right 
> mixing/resampling plugins loaded?

ALSA is limited to Linux, it is everything else than portable. ALSA is
not network transparent. ALSA ist not esound compatible. ALSA is a
driver API, not a sound server API.

And JACK isn't a sound server, its an audio connection kit.

> I can see it has esound protocol compatibility, which is interesting, 
> and presumably means it's network transparent.

Yes. Even without loading the esound compatibility module polypaudio
is network transparent when using the native protocol.

> The thing is, that there are already bazillions of sound servers. What 
> is the rationale behind having a sound server as opposed to ALSA plugins 
> which do the same thing (and for other platforms, it would be delegated 
> to their native audio layers).

See above.

> >What are the features required for a common sound daemon for all Linux
> >desktop environments?
> Well I guess the most important is backwards compatibility with 
> everything. Unless you throw in ALSA userspace mixing as well with dmix 
> or whatever any sound server will block the audio device so it *has* to 
> be able to be used with any apps, even older apps without plugins for 
> instance, by using LD_PRELOAD tricks like aoss or esddsp (?).

Polypaudio is intended for replacing esound/arts, not OSS or ALSA. So
I see no need in adding a compatibility layer for OSS/ALSA superseding

Polypaudio is not for professional audio, polypaudio should be a sound
server for desktop environments. Professional audio people will always
want to access hardware at the lowest level possible. Every software
layer will only increase latency. 

> After all, most people want a sound server for mixing, so if it doesn't 
> mix everything together, it's not really fulfilling its mission.

It mixes "everything" together. Everything that connects to the sound
server through its native protocol or the esound procotol (or few more
other protocols)


name { Lennart Poettering } loc { Hamburg - Germany }
mail { mzft (at) 0pointer (dot) de } gpg { 1A015CC4 }  
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