[pulseaudio-discuss] Odd app behavior with PULSE_PROP="filter.want=echo-cancel"

[Raman Gupta]

When I start Zoiper with PULSE_PROP="filter.want=echo-cancel", it
demonstrates some odd behavior. It ends up creating many Echo-Cancel
Sink and Source streams, and I am unable to select my USB headset as
the source of any of them.

I think, based on the discussion around a recent crasher bug I
reported, Zoiper is trying to be too clever, without being clever
enough, and is actually trying to open up various streams to all of
the Pulse Input and Output devices. Is this just a Zoiper issue, or is
there something I can do on the Pulse side to solve this?

I think one option is load the echo-cancellation module once in
/etc/pulse/default.pa and then use the volume control to manually hook
up Zoiper to that module.

Regards,
Raman