[LAU] Soundcard question: Was "Equivalent to reason"

J M Needham J.M.Needham at bath.ac.uk
Fri May 16 08:55:39 EDT 2008


Thanks for this Paul -- sorts that out nicely. So off to get a USB
soundcard for my laptop...

On Fri, 16 May 2008, Paul Davis wrote:

>
> On Fri, 2008-05-16 at 11:20 +0100, J M Needham wrote:
> > Dear all,
> >
> > Forgive me for not understanding this, but I've also heard conflicting
> > things on Alsa-User. On my PC (old H/W, Ubuntu Hardy Heron, SB audigy) I
> > can play sound through apps connected to jack and apps going direct to
> > Alsa at the same time. On my Debian sid box, I cannot have two appps
> > playing music at the same time. My Laptop, running Ubuntu GG (s/c HDA
> > intel) also behaves like this, whereas my friend's PC can do what my
> > Ubuntu HH box can do (new H/W, SB Audigy new(ish)), and
> > both have been able to do this since we both switched at Edgy Eft.
> >
> > I don't understand this. Some people say that you cannot play sounds from
> > aps connected to Jack and apps not using jack at the same time, which
> > contradicts some of my experience and the experience of Joakim Hernberg
> > [below] so what's the difference? What files do I need to look at to find
> > the difference if there is any.
> >
> > Is this a h/w or s/w issue? It's clearly possible, so why is there the
> > belief that it can't happen?
>
> its both.
>
> there is some audio hardware that supports "multi-open" directly in
> hardware. i believe that your SB Audigy is one such device. this means
> that multiple (typically somewhere from 8-32) applications can open it,
> and the hardware mixes everything down to the outputs.
>
> this type of h/w has become massively less common as Intel-HDA has
> spread, since this "specification" leaves mixing like this to device
> drivers and/or some OS audio infrastructure. mixing JACK & non-JACK
> applications with audio interfaces that do not provide hardware
> multi-open is essentially impossible (or just so kludgy that i don't
> even want to discuss it).
>
> --p
>
>
>
>
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>




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