[pulseaudio-discuss] a sounding program with several output streams

[Colin Guthrie]

'Twas brillig, and Roman Beslik at 02/01/12 22:55 did gyre and gimble:
> There are programs which output several sound streams. The reason is
> that streams can be routed to different sound cards (if a user have
> them) for enhanced user experience. E.g., Skype outputs incoming call
> ringing to speakers and talk to a handset. Because programs do not chose
> a sound card when working with PulseAudio, PulseAudio must support
> several streams from 1 program. Is this supported? 

Yes, programs can create as many streams as they want (each sink will
only support (I think) 32 streams, but that's just to prevent too much
craziness! :)

> Now Skype sends
> incoming call ringing to Gnome system sounds and talk to PulseAudio.
> Thanks to Gnome, I managed to split Skype's streams. But this looks like
> some twisted solution. What if I had not Gnome?

Then you can also do it in KDE (kmix supports a separate slider for
Event Sounds too).

This is generally good practice and Skype is actually doing a pretty
good job at tagging their streams correctly (signin/signout/ringing
sounds are mostly tagged as "event" and the actual phone streams (both
in and out) are tagged as "phone" - tho' there are still a couple bugs
at their end with mis-tagging).

Over all this metadata allows for interesting things to happen
automatically. For example if someone has a headset (USB or Bluetooth)
we can automatically use it for phone calls which is (with ~90%
liklihood) what the user wants. Obviously the user should still have
manual control over this, but if we can "do the right thing"(tm) out of
the box by using this additional metadata then all is well.

Anyway, the Desktop Environment the user is using should provide the
necessary UIs to control and interact with PA if they want to use it by
default. Both GNOME and KDE do this now (and both default (or require)
PA). Other DE's I'm less sure about, but it's fully within their control.

Col


-- 

Colin Guthrie
gmane(at)colin.guthr.ie
http://colin.guthr.ie/

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