Echo cancellation for calls with pipewire on Librem 5

Some technical details https://gitlab.com/mobian1/callaudiod/-/issues/13 @devrtz do you have an idea what needs to be done on trixie/pipewire? Seems to be fine on bookworm/pulseaudio.

Please review the text on https://opencollective.com/dephcom/projects/pipewire-echo?status=projectCreated

There is some work in progress for anyone who wants to try fixing it https://salsa.debian.org/Mobian-team/devices/librem5-tweaks/-/commits/wip/kop316/pipewire

Shared by Chris https://fosstodon.org/@kop316/114398582666998648

More technical details on what is needed https://gitlab.freedesktop.org/pipewire/pipewire/-/issues/4170

A workaround would be to switch back to pulse audio until we can configure echo cancel in pipewire. We can refer to https://source.puri.sm/Librem5/librem5-base/-/commit/e55f39d8cb1137bfec68badec7da91fb88fc7a18 and it seems this is simpler in Trixie as it has a pipewire video only profile already. So we just need the systemd presets and allow pulseaudio as alternate dependency in mobian-base.

So I'm able to successfully switch back to pulseaudio in mobian trixie and confirmed echo issue is fixed. But we will keep the bounty open for people who want to fix this in pipewire.

I am reaching out to someone who can potentially help us implement this https://social.masto.host/@praveen/115111428396587819

I reached out to Arun Raghavan as suggested by https://social.masto.host/@pabloyoyoista@treehouse.systems but they are unable to take up this task at the moment but gave two options that would help anyone interested to implement this.

There are two options:

  1. Do what was suggested in https://gitlab.freedesktop.org/pipewire/pipewire/-/issues/4170#note_2518968, which is basically to write a WirePlumber Lua script to load the echo cancel module based on a filter.want property, and route to that instead of the intended sink/source

  2. Statically load module-echo-cancel in your device config, and just route to the virtual sink/source based on the filter.want property (this would be even simpler than (1))

Have you considered asking on the PipeWire Matrix channel if someone wants to step up to do this? Might get more eyeballs there.

We got a response to our bounty.

Hi,

I’m interested in taking the PipeWire echo cancellation bounty.

I reviewed the scope around PipeWire’s PulseAudio compatibility for "filter.want" / "filter.apply", specifically for the Mobian Trixie / Librem 5 echo-cancel use case.

Before I start implementation, could you please confirm that the bounty is still available and that you’re happy for me to work on it?

My plan is to keep the work focused:

• inspect current PipeWire master and the PulseAudio behavior;

• implement the missing compatibility;

• add or update tests where feasible;

• submit the work upstream for review;

• coordinate Mobian Trixie / Librem 5 validation with you if hardware-specific testing is needed.

I won’t start substantial implementation until you confirm that the bounty is available for me to take.

Thanks,
Franklin

I'm going to confirm the bounty is still available. Very excited to see this interest.