PipeWire (and WirePlumber) audio pipeline for "Local Audio-Out" and/or "Local Audio-In" for the Music Assistant add-on?

[Hedda]

Could if be a good idea to implement PipeWire (and WirePlumber) audio pipeline(s) for "Local Audio-Out" and "Local Audio-In" in HAOS with the Music Assistant add-on?

• https://en.wikipedia.org/wiki/PipeWire

Why a operatingsystem like Home Assistant Operating System would want use PipeWire is summerized in their FAQ here ("Linux has 1 kernel API named ALSA. PipeWire unifies the 2 user-space servers in practical use: PulseAudio and JACK. With 1 Kernel and 1 user-space audio subsystem, Linux has reached the ideal situation."). PipeWire has been used since Fedora 27 (November 2017) for Wayland screen sharing and has been the default audio server since Fedora 34 (April 2021).

• https://gitlab.freedesktop.org/pipewire/pipewire/-/wikis/FAQ#why-another-audio-standard-linux-already-has-13-of-them

Some additional benefits to using PipeWire:

• You can connect external speakers via Bluetooth A2DP (Advanced Audio Distribution Profile).
• You can use filters and rules.
  • For local voice assistant microphone input can potentially use noise reduction and other audio filters.

I think that PipeWire could more or less also be used as a drop-in replacement for applications that normally interact with PulseAudio, JACK, or ALSA. One specific use case for PipeWire (and WirePlumber) could be useful for is "Local Audio-Input" with the Music Assistant add-on?

• https://github.com/orgs/music-assistant/discussions/1156

  • Added Local Audio Source Provider music-assistant/server#2356

WirePlumber is an optinal modular high-level session / policy manager library that wraps PipeWire's API for external daemons/tools:

• https://pipewire.pages.freedesktop.org/wireplumber/

  • https://fedoraproject.org/wiki/Changes/WirePlumber

  • https://wiki.archlinux.org/title/WirePlumber

  • https://wiki.gentoo.org/wiki/WirePlumber

Was mostly wondering if adding PipeWire support could achieve a better plug-and-play experience (as per HA roadmap goals)?

• https://bootlin.com/blog/an-introduction-to-pipewire/

I have not verified but understand that PipeWire has low-latency performence as long as use high audio sample rate?

• https://gitlab.freedesktop.org/pipewire/pipewire/-/wikis/Performance#latency

As I understand PipeWire (and WirePlumber) depends on ALSA and them working in userspace making them useful.

• https://www.youtube.com/watch?v=HOsp-JlIkkY

Link to PipeWire FAQ for reference:

• https://gitlab.freedesktop.org/pipewire/pipewire/-/wikis/FAQ

ALSA is still the kernel-level interface, so concept-wise PipeWire just unifies JACK and PulseAudio into one service, and handles a few other things as well. From a user perspective it more or less just merging everything into one unified interface, which should be more user-friendly. With the idea behind PipeWire being to be compatible with every other audio subsystem on Linux, and unify audio and video streaming under one roof, as well as fix the audio latency of PulseAudio.

• https://gitlab.freedesktop.org/pipewire/pipewire/-/wikis/home

PipeWire is generally recommended over PulseAudio for modern Linux, offering lower latency, better Bluetooth support, and native compatibility with both PulseAudio and JACK applications, making it superior for both general use and and music production.

For backward-compatiblity a tip is that can on theory make PipeWire backwards-compatible with PulseAudio if use pipewire-pulse, see:

• https://docs.pipewire.org/page_man_pipewire-pulse_1.html

DESCRIPTION: pipewire-pulse starts a PulseAudio-compatible daemon that integrates with the PipeWire media server, by running a pipewire process through a systemd service. This daemon is a drop-in replacement for the PulseAudio daemon.

PipeWire can also replaces JACK but provides a jack-compatible API with results being that JACK clients being redirected to PipeWire. See:

• https://docs.pipewire.org/page_man_pw-jack_1.html

DESCRIPTION: pw-jack modifies the LD_LIBRARY_PATH environment variable so that applications will load PipeWire's reimplementation of the JACK client libraries instead of JACK's own libraries. If PipeWire's reimplementation of the JACK client libraries has been installed as a system-wide replacement for JACK's own libraries, then the whole system already behaves in that way, in which case pw-jack has no practical effect.

[scyto]

take a look at this for your BT playback scenario

https://github.com/scyto/ha-bluetooth-audio-manager

this would help with your audio our to BT devices, for audio in I am blocked by lack of SCO support in haos audio (i may take a crack at it at some point as it should be just the additon of a couple of modules to PA config hass audio container)

I do think pipewire is likely the long term direction but it is not the magic solution either - for example there are may broken scenarios in pipewire for multiplexing or de-multiplexing audio that seem just plain brokem, and too many of their utils assume an X installation (e.g. the hdjackretask app). i had to build my own for that one lol

[Hedda]

FYI; regarding Bluetooth speaker output be aware that Music Assistent community member has put together a solution/workaround that uses Sendspin client as a Docker container with Bluetooth support:

• https://github.com/loryanstrant/Sendspin-client

Might be good for inspiration? His Docker container allows you to utilise the Linux devices you have around the place, connect them to Bluetooth speakers, and present them in Music Assistant as a Sendspin client. He explains it in more details here:

• https://github.com/orgs/music-assistant/discussions/4677

It is made for running on headless systems like Raspberry Pi or on other computers with Home Assistant installations. He even made it present a little web interface for diagnostics/configuration/monitoring.

Anyway, please start a new separate dedicated discussion thread out ”Bluetooth output to external speaker” is this forum.

[Hedda]

For reference, here are two indirectly related feature requests for Open Home Foundation’s experimental Linux-Voice-Assistant project (to make remote Linux-based voice assistant satellites running on Raspberry Pi SBC-type computers) that adds additional use case for Pipewire in HAOS. See:

• Build a stripped-down Linux OS distro based on Home Assistant Operating System and package Linux Voice Assistent in the Home Assistant App/Addon format to run on it? OHF-Voice/linux-voice-assistant#161

And

• PipeWire instead of PulseAudio OHF-Voice/linux-voice-assistant#94