Linux system audio for Meeting Mode

September 15, 2026 · View on GitHub

OpenWhisper can capture the default output mix on Linux through PulseAudio monitor sources. That covers:

native PulseAudio
PipeWire with the pipewire-pulse compatibility service

Public Meeting Mode promotion for Linux stays gated until the manual x86_64/aarch64 hardware release matrix is attested. On a current build you can still try the path after the versioned Linux preview acknowledgement; the app will run the same diagnostics and remediation dialog.

ALSA-only desktops are supported by installing a Pulse-compatible session, not by a separate ALSA loopback backend.

Detection is SoundCard-first. OpenWhisper accepts only a positively identified loopback that SoundCard exposes as <default-sink-id>.monitor or explicitly keys to the default sink. Most desktops need nothing else. If a server uses a nonstandard monitor name, OpenWhisper optionally uses pactl to prove the exact Monitor of association; it never guesses from a fuzzy name or accepts another sink's monitor.

Diagnostic keys

Every readiness failure carries a stable key. The in-app dialog and this guide use the same keys.

Key	Meaning	Typical fix
`soundcard_missing`	Python `soundcard` package not importable	Install into the app venv
`libpulse_missing`	Pulse client library (`libpulse.so.0`) missing	Install distro Pulse client package
`audio_server_unavailable`	No Pulse-compatible server answered	Install/start Pulse or PipeWire-Pulse
`pipewire_pulse_missing`	PipeWire is up without Pulse compatibility	Install/enable `pipewire-pulse`
`default_sink_missing`	No default output sink	Choose a default output in desktop settings
`pactl_missing`	Nonstandard monitor association needs optional `pactl` fallback	Install the distro package that provides `pactl`
`monitor_source_missing`	Default sink has no validated loopback monitor	Confirm monitor source; do not swap stacks casually
`monitor_open_failed`	Monitor found but open/read timed out or failed	Close exclusive apps; restart user audio services
`unsupported_architecture`	Not x86_64/amd64 or aarch64/arm64	Unsupported
`unknown_failure`	Unexpected probe error	See verification commands; open an issue with logs

Optional `pactl` fallback

pactl is not required when SoundCard can directly prove the default-sink loopback. For nonstandard monitor names, install it with:

Debian/Ubuntu: sudo apt install -y pulseaudio-utils
Fedora/RHEL: sudo dnf install -y pulseaudio-utils
Arch: sudo pacman -S --needed libpulse

These packages provide diagnostics and fallback association; system-audio capture itself remains optional.

Quick checks

When pactl is installed:

pactl info
pactl list short sinks
pactl list short sources
python scripts/probe_linux_loopback.py

A healthy setup shows a Pulse or PipeWire server name, a default sink, and a matching monitor source. Silence alone is not a failure.

Stack-aware fixes

`soundcard_missing`

python -m pip install 'soundcard>=0.4.3'
python -c "import soundcard; print(soundcard.__version__)"

`libpulse_missing`

Debian/Ubuntu: sudo apt install -y libpulse0
Fedora/RHEL: sudo dnf install -y pulseaudio-libs
Arch: sudo pacman -S --needed libpulse

Verify:

python -c "import ctypes; ctypes.CDLL('libpulse.so.0')"

`pipewire_pulse_missing` (PipeWire without Pulse compatibility)

Only when the probe classified the stack as PipeWire without Pulse:

Debian/Ubuntu: sudo apt install -y pipewire-pulse wireplumber
Fedora/RHEL: sudo dnf install -y pipewire-pulseaudio wireplumber
Arch: sudo pacman -S --needed pipewire-pulse wireplumber

Then:

systemctl --user enable --now pipewire pipewire-pulse wireplumber
systemctl --user is-active pipewire-pulse

Sign out and back in if the services do not appear immediately.

Rollback:

systemctl --user disable --now pipewire-pulse

`audio_server_unavailable` (no Pulse-compatible server answered)

When nothing answered, recover the stack you already use first. A temporarily stopped native PulseAudio session must not be “fixed” by installing PipeWire.

systemctl --user status pulseaudio pipewire pipewire-pulse wireplumber
systemctl --user is-active pulseaudio
systemctl --user is-active pipewire-pulse
pactl info
pactl list short sinks
pactl list short sources

After you identify the installed stack, restart only that one (do not chain Pulse into PipeWire with ||):

# Native PulseAudio only:
systemctl --user restart pulseaudio

# OR PipeWire + pipewire-pulse only:
systemctl --user restart pipewire pipewire-pulse wireplumber

Only when you have confirmed no Pulse-compatible server is installed at all (for example a fresh ALSA-only image) should you install one deliberately:

Debian/Ubuntu native Pulse: sudo apt install -y pulseaudio
or PipeWire with compatibility: sudo apt install -y pipewire pipewire-pulse wireplumber
Fedora/RHEL: sudo dnf install -y pipewire pipewire-pulseaudio wireplumber
Arch: sudo pacman -S --needed pipewire pipewire-pulse wireplumber

Prefer restarting an existing Pulse or PipeWire user session before replacing packages.

Transient sink / monitor / open failures on a live stack

Keys: default_sink_missing, monitor_source_missing, monitor_open_failed.

These do not mean you should install a competing audio stack.

Choose a default output in desktop sound settings.
Play a short sound to wake the device.
Confirm monitors:

pactl info
pactl list short sinks
pactl list short sources

If the stack is already PipeWire-Pulse:

systemctl --user is-active pipewire pipewire-pulse wireplumber

If the stack is native PulseAudio, restart or inspect Pulse only — do not enable PipeWire just because a sink was missing.
Retry detection in OpenWhisper. Sign out/in only if a service restart was required for the monitor to appear.

`unsupported_architecture`

Meeting Mode’s Linux path covers x86_64/amd64 and aarch64/arm64 only.

Verification after any fix

pactl info | grep -i 'Server Name'
pactl list short sinks
pactl list short sources
python scripts/probe_linux_loopback.py

probe_linux_loopback.py exits 0 only when dual-channel capture is ready.

Distro caveats

Unknown package families never receive automatic apt/dnf/pacman install lines; use the generic guidance and your distro docs.
Flatpak/sandboxed installs are out of scope for this guide.
NVIDIA CUDA on Linux is separate (requirements-gpu.txt) and is not required for Meeting Mode capture.
ARM64 Meeting Mode is functional (CPU/cloud transcription) once attestation passes; CUDA is not promised on ARM64.

Notes

OpenWhisper never runs package or service commands for you.
A microphone-only choice applies only to the current meeting and is not persisted.
Public “supported on Linux” marketing stays off until the hardware release matrix is attested, even though the implementation is present.