linuxaudio.org

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:
>

quoted text
> 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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