[pulseaudio-discuss] alsa: split up 6-channel streams into 3 stereo pairs?

Tanu Kaskinen tanuk at iki.fi
Mon Nov 14 11:27:58 PST 2011

On Sat, 2011-11-12 at 17:14 +0100, Daniel Mack wrote:
> A 6-channel audio device I wrote support announces a single ALSA
> subdevice that has to be opened as a whole in order to access all six
> channels. However, I would like to offer the channels as three pairs of
> stereo (for both directions), so stereo clients can be routed to each of
> them individually.
> From what I saw in the alsa-mixer module code, there is no way to
> specify such things of settings in the profile-sets, right? Are there
> any plans to support these kind of setups?

So even if the card would be used as three stereo pairs, Pulseaudio
would still have to open the device with six channels, right?

There's module-remap-sink, which can be used to split a six-channel sink
into three stereo sinks (while keeping the six-channel sink also
available). For sources there's currently nothing. You're right in that
there's no way for you to write a profile-set configuration file that
would make the stereo sinks available out-of-the-box.

As for plans, I don't think there are any plans to do anything about
this in the near future. I think Colin has mentioned that a GUI for
configuring this kind of things would be nice, but that's about it. This
is the first time I hear the idea of extending the alsa-mixer
configuration to support this kind of setups. Sounds like a good idea.
Now if we just could find someone to do the work...


More information about the pulseaudio-discuss mailing list