More info about jack

David Bishop tech at
Fri Feb 21 17:22:27 GMT 2003

> OK, looking at Jack, they say that they're low-latency and aRts isn't.  If
> that's true, then I think aRts (especially that capital R) is badly named.
> I hope Stefan is around and reading this thread to comment on this.

Unfortunetly, I am fairly positive it's true.  I don't think, however, that it 
is a problem for 99% of the users, for the same reason that we don't all need 
hard-realtime kernels.

> > If arts did function as a jack host it could become the end user choice
> > since jackd more directed toward professional users.
> Absolutely.
> So, did you want to work on this?  I can't imagine anyone would object to
> shipping a plugin that allows the use of jack plugins.

Dunno about using plugins, as I don't see a ton (any?) plugins for jack that 
are all that exciting.  This is a case where jackd is *not* a full arts 
replacement, as (afaict), it doesn't do any decoding for you, i.e., it has no 
PlayObject equivalents, it expects you to decode before getting to it.  Or 
maybe I'm misunderstanding what you are saying here.

> However, I do think that an artsd-emulating jack plugin would not belong in
> the KDE release, but rather would best fit as a separate package that
> serves as a replacement for the regular arts releases.  The only changes
> needed to KDE should be to the Sound Server kcontrol module, to be able to
> choose and configure jackd instead of artsd.

Long, long time ago (in this thread), I mentioned that if I ever get my 
current arts project done, I would look into making it so that artsd could 
use jackd as an output plugin, like it uses alsa, or oss right now.  So it 
wouldn't be a case of having a seperate jackd configuration module or 
anything, just choose it as the output.  This would allow someone using, say, 
Rosegarden to be able to use jack with it, and other, arts-enabled apps, at 
the same time.  Now, my promise to look into this and $1 will get you a 
hamburger at McDonald's, and I'm not expecting you to jump up and down with 
joy at a (relatively) nameless stranger talking about stuff without code.  
But there *is* someone interested in this stuff, so I wouldn't dismiss it out 
of hand :-)

*obligatory complaint*
Um, the docs on arts really suck :-(  Maybe I'm just spoiled with the great Qt 
and KDE docs, but it's really disappointing to find that even the headers are 
poorly commented (for instance, see Arts::Refiller at, and based soley 
off of that (or anything else on that site), tell me what it's return value 
is supposed to represent, or what, exactly, is supposed to be in buffer after 
it returns.  I'm having to figure this stuff out by reading the source to 
other PlayObjects :-((  (thanks for the pointers to those, by the way.  the 
corrollary to the "docs suck" complaint would be that the mailing list is 
*end of obligatory complaint*

I really like arts, I use noatun to listen to my tunes, I use the -ao arts 
option with mplayer, kmplayer in konq, kmidi to listen to my compositions 
from Rosegarden.  I'm not here to bury arts, but to praise it B-)

"Yousa steala precious from meesa!" - Jar-Jaromir


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