Pipewire Audio Driver

[rtbo]

Resolves (on linux): #18701

This is a new audio driver for Linux, that uses the Pipewire API, (and therefore will only be used when Pipewire is installed and running).
For system that do not have pipewire, it will fallback to ALSA automatically.

Pipewire performs a setup negotiation to match what is requested by the app and what is setup on the system.
So the buffer size is more a request for a certain latency rather than something imperative.
I've added support for "System default" buffer size where we don't request anything specific to pipewire.

In general, pipewire will handle gracefully all sorts of corner cases.
My observations are for a low latency playback, free of any glitch, in all situations.

Pipewire also provides the devices available, so the user can choose any playback device available, including bluetooth.
I didn't test yet with USB external device.

Relates to #23439

• I signed the CLA
• The title of the PR describes the problem it addresses
• Each commit's message describes its purpose and effects, and references the issue it resolves
• If changes are extensive, there is a sequence of easily reviewable commits
• The code in the PR follows the coding rules
• There are no unnecessary changes
• The code compiles and runs on my machine, preferably after each commit individually
• I created a unit test or vtest to verify the changes I made (if applicable)

[RomanPudashkin]

Great job, thank you so much! I asked @DmitryArefiev to test it. @MarcSabatella could you also test it? Thanks!

[DmitryArefiev]

@rtbo Tried on my LinuxUbuntu 22.04. The build doesn't run..

Here is terminal output:

dima@dima-VivoBook-ASUSLaptop-X415JAB-X415JA:~$ '/home/dima/Desktop/MU4_242241603_Lin_23939_Pipewire Audio Driver(1)/MuseScore-Studio-4.4.0.242241603-x86_64.AppImage' -d 
/lib/x86_64-linux-gnu/libjack.so.0
/lib/x86_64-linux-gnu/libnss3.so
Warning: Ignoring WAYLAND_DISPLAY on Gnome. Use QT_QPA_PLATFORM=wayland to run on Wayland anyway.
[D] pw.context [pipewire.c:231 load_spa_handle()] load lib:'support/libspa-support' factory-name:'support.log'
[D] pw.context [pipewire.c:115 open_plugin()] can't load /root/build_tools/pw-1.0.4/lib/spa-0.2/support/libspa-support.so: /root/build_tools/pw-1.0.4/lib/spa-0.2/support/libspa-support.so: cannot open shared object file: Permission denied
[D] pw.context [pipewire.c:231 load_spa_handle()] load lib:'support/libspa-support' factory-name:'support.cpu'
[D] pw.context [pipewire.c:115 open_plugin()] can't load /root/build_tools/pw-1.0.4/lib/spa-0.2/support/libspa-support.so: /root/build_tools/pw-1.0.4/lib/spa-0.2/support/libspa-support.so: cannot open shared object file: Permission denied
[I] pw.context [pipewire.c:647 pw_init()] version 1.0.4
[D] pw.thread-loop [thread-loop.c:146 loop_new()] 0x62c279642400: new name:pw-driver-loop
[D] pw.context [pipewire.c:231 load_spa_handle()] load lib:'support/libspa-support' factory-name:'support.system'
[D] pw.context [pipewire.c:115 open_plugin()] can't load /root/build_tools/pw-1.0.4/lib/spa-0.2/support/libspa-support.so: /root/build_tools/pw-1.0.4/lib/spa-0.2/support/libspa-support.so: cannot open shared object file: Permission denied
[E] pw.loop [loop.c:67 pw_loop_new()] 0x62c2796a2ba0: can't make support.system handle: No such file or directory
/tmp/.mount_MuseScTyp4NK/AppRun: line 26:  3320 Segmentation fault      (core dumped) "${APPDIR}/bin/mscore4portabledev" "$@"

[MarcSabatella]

Same.

[rtbo]

Thanks for the code review and the tests.
I have difficulties to make the AppImage work. I'm currently running local tests to see which PW plugins must be included.
I'm nearly done with it, I will let you know.

[rtbo]

AppImage should work now.
It will use the pipewire shared object from your system. If pipewire is not installed, it will load the SO packaged in the AppImage and fallback to ALSA gracefully because of missing plugins.

@DmitryArefiev have you installed pipewire on your ubuntu-22.04? (installed by default starting 22.10). If not you should see the same as the master branch.
@MarcSabatella for you the choppy sound should be gone, and you can choose a playback device in the audio preferences.

[MarcSabatella]

Sounds promising! Unfortunately, segfault at startup, just after the splash screen. Log file attached from a run with "-F -d":

log.txt

[rtbo]

Unfortunately I don't have enough info to debug the issue. Please repeat with the last build.

[MarcSabatella]

Here you go:

log.txt

[rtbo]

Thank you it should be OK now. There was a stupid typo in the code.
Your device recognition doesn't seem to work same as mine.
Please see if you have relevant device names in the preferences.
Bluetooth and USB hotplug should normal work as well.

[MarcSabatella]

Crash is gone indeed, and I do see a drop-down for device, although it doesn't tell me anything particularly useful - I've never heard of whatever it is showing me as the only option. But I assume that's something set up by the ChromeOS audio system.

Behavior is decent, with good playback at 48 or 44.1 and buffer sizes about 104. Buffer sizes below are problematic in a new way: no sound at all during note input, and on playback, when stopping, the last note played gets extended for a very long time:

Screen.recording.2024-08-18.10.52.13.AM.webm

Nothing interesting is printed to console at that time, but I've attached a log anyhow:

log.txt

[RomanPudashkin]

You forgot to rename MUSE_AUDIO_LINUXAUDIODRIVER_H :) But you can also replace it with #pragma once

[RomanPudashkin]

Buffer sizes below are problematic in a new way

@rtbo regarding this issue: can we limit the min size to this constant MINIMUM_BUFFER_SIZE (audiotypes.h)?

[DmitryArefiev]

Tested on LinuxUbuntu 22.04.4 LTS (Wayland)

@rtbo Now it doesn't crash, but I don't have a sound during note input and playback doesn't start

MuseScore_240819_120345.log

@DmitryArefiev have you installed pipewire on your ubuntu-22.04? (installed by default starting 22.10). If not you should see the same as the master branch.

I think not. I still have 22.04.4 LTS after installing all updates