Seperate audio outputs for fedora- is this limited by my soundcard or the number of outputs on my motherboard?

[Samuel Kidman]

Hello

Another audio question:

I want to be able to play one audio source through my headphones (say from
one application) and then play another audio source through my line out port
(from another application). Is this possible? I have an integrated
soundcard. The computer is a Hewlett-Packard DC7600. Just wondering if the
sound card on this computer is capable of piping two different audio sources
at the same time, and if so, how this can be accomplished using fedora and
alsa or pulseaudio. Maybe even Jack?

Regards, Sam

[stan]

On Sun, 3 Oct 2010 01:11:01 +0800
Samuel Kidman  wrote:
> I want to be able to play one audio source through my headphones (say
> from one application) and then play another audio source through my
> line out port (from another application). Is this possible?

Short answer, no.

I think there are some very high end audio cards that have more than
one processing pipeline, but I have never owned one.  With a standard
card, this is not possible because the "engine" can only process one
stream at a time.  The analog output has to go to the output device
continuously, so it can't do more than one at a time because there is
no time. :-)  In other words, to have two sound streams running
simultaneously to different outputs, you have to have two sound
devices.  Jack and pulseaudio solve a different problem; mixing
multiple inputs before sending them to the "engine", and routing the
output to multiple places.

Just buy a cheap USB soundcard (get one that adheres to the standard,
or if it doesn't, has been reverse engineered to work in alsa), and you
can do what you want.  Desktop users can use USB, but also can use a
cheap PCI card also.

[Suvayu Ali]

On 2 October 2010 12:04, stan  wrote:
> I think there are some very high end audio cards that have more than
> one processing pipeline, but I have never owned one.

I think the "very high end" comment is probably not true anymore. I
used to own an Intel HDA integrated chip couple of years back capable
of doing that (I primarily used Windows XP back then) . However the
driver support used to be rather patchy even on Windows, but it did
work. I think on supported hardware with today's linux systems a
combination of pulseaudio and ALSA can achieve that without much
hassle. (have to admit I haven't tried it yet)

[stan]

On Sat, 2 Oct 2010 16:21:01 -0700
suvayu ali  wrote:
> On 2 October 2010 12:04, stan  wrote:
> > I think there are some very high end audio cards that have more than
> > one processing pipeline, but I have never owned one.
>
> I think the "very high end" comment is probably not true anymore. I
> used to own an Intel HDA integrated chip couple of years back capable
> of doing that (I primarily used Windows XP back then) . However the
> driver support used to be rather patchy even on Windows, but it did
> work. I think on supported hardware with today's linux systems a
> combination of pulseaudio and ALSA can achieve that without much
> hassle. (have to admit I haven't tried it yet)

If this is now true, I agree it should be dead simple to use under
pulseaudio, since pavuctl will show a separate device for each
pipeline (subdevice in alsa terminology), as long as alsa also
recognizes them. All that would need to be done is to set up each
of the two applications to use a different pulseaudio device.