Audio-Gui

A small, Qt6 desktop app for controlling Linux audio on ALSA-only systems — no PulseAudio daemon, no PipeWire. It combines the everyday alsamixer controls with a toggle for the bundled PulseAudio-compatibility bridges, so apps that only speak PulseAudio still get sound.

What it does

• Mixer — horizontal volume sliders with mute toggles for Master, Headphone, Speaker, Microphone and Mic Boost (only the controls your card actually has are shown), driven directly through libasound (snd_mixer). External changes (e.g. amixer, media keys) are reflected live.
• Output level meter — a live stereo peak meter fed by whichever bridge is running (the bridge publishes its mixed peak in a shared-memory page). Output meters do not work in ALSA (no bridge)
• Audio options — a 3-way routing choice (the two bridges are mutually exclusive, they bind the same PA socket):
• PA Bridge → ALSA (default) — runs pa-alsa-bridge.
• ALSA (no bridge) — nothing runs; only native-ALSA apps get sound.
• PA Bridge → JACK — runs pulse-jack-bridge, exposing pulse_bridge playback ports in a JACK patchbay. Needs to be connected manually in Jack Graph, Qjackctl
  Enabled only while jackd is running (detected live).
• Output device — a dropdown that switches the bridge's output between the detected cards (internal / USB / HDMI) live, without restarting the app. Devices are discovered straight from libasound (no shelling out) and the list refreshes automatically when you plug or unplug a USB interface. The mixer controls follow the selected card; HDMI outputs, which usually have no mixer controls, show a placeholder. The choice persists and is restored at login. (Applies to the PA Bridge → ALSA path; the dropdown is disabled in the other modes.)
• Switches — Capture and IEC958 (S/PDIF) toggles, when the card provides them.
• Appearance — a self-contained modern theme (Fusion + stylesheet) that looks the same on every system rather than inheriting the user's Qt/GTK theme. A dark/light toggle (dark by default) and an accent colour (green / orange / blue / yellow) sit at the bottom of the window; both choices persist.

The bridge runs independently of the GUI: it keeps playing after you close the window, the chosen mode is remembered, and it is brought back up at login by an XDG autostart entry (audio-gui --restore) — so PA-compat audio works without the GUI ever being opened and survives a reboot as whatever was last selected. The autostart entry (~/.config/autostart/audio-gui-restore.desktop) is created/kept current the first time you run the GUI. Switching modes in the GUI updates both the running bridge and the saved choice.

There is no PulseAudio server, no PipeWire anywhere — the bridges are minimal PA-protocol sockets that expose just enough for apps to believe PulseAudio is present. Only UNIX sockets are used (no dependency on systemd).

The pa-alsa-bridge implements both playback and capture: besides games and browsers, it negotiates the extended format API used by players like VLC (which send the stream's PCM format as a format list rather than a plain sample spec) and answers sink-input introspection, so those players connect and play. Each playback stream is resampled from the app's own sample rate to the device rate and its sample format converted (16-bit, 24-bit packed, 24-in-32-bit and 32-bit integer, and 32-bit float are all accepted), so players that don't adapt to the advertised rate or format (e.g. Parole playing 24-bit FLAC/WAV) still play cleanly. Per-stream volume and mute are honoured (the cubic PulseAudio mapping), so a player's own volume slider works. It also exposes a monitor source (alsa_sink.monitor) with real record streams, so screen recorders and capture apps (Simple Screen Recorder, OBS, Audacity, voice chat) can record the mixed output. The monitor is taken post-mix, so it is unaffected by live output-device switching. Record streams are likewise resampled/converted to whatever sample rate and format the recording app requests.

On first run, if you have no ALSA configuration at all (neither ~/.asoundrc nor /etc/asound.conf), Audio-Gui writes a baseline ~/.asoundrc that sets up a software-mixing (dmix/dsnoop) default on your internal card, so the bridge and ordinary ALSA apps can share the device on any distro. If you already have either file it is left untouched — delete the generated ~/.asoundrc to fall back to ALSA's built-in default.

Everything runs at user privilege; opening a specific card (hw:/plughw:) needs only membership of the audio group, exactly as opening default does.

Install (release tarball)

Grab a release audio-gui-<version>.tar.gz, unpack it, and run the installer:

tar xzf audio-gui-<version>.tar.gz
cd Audio-Gui
chmod +x install.sh && ./install.sh

install.sh installs everything per-user, no root (binaries to ~/.local/bin, a menu entry to ~/.local/share/applications) — only the dependency step uses sudo to pull the runtime packages via your distro's package manager (apt/dnf/yum/pacman/zypper/apk). It also writes a generic ~/.asoundrc, backing up any existing one to ~/.asoundrc.bak. Useful flags:

• --from-source — build from the bundled source instead of the prebuilt binaries.
• --no-deps — don't touch the package manager (install dependencies yourself).
• --no-asoundrc — leave ~/.asoundrc alone.
• PREFIX=/usr/local ./install.sh — system-wide instead of ~/.local.

The tarball ships prebuilt binaries plus the full source. By default install.sh uses the prebuilt binaries when they resolve their libraries on your system; if they can't (different glibc/Qt6), it automatically builds from the bundled source instead. Remove with ./uninstall.sh (--purge also drops saved settings).

Prebuilt binary requirements

The released binaries are built on Debian 12 (bookworm), so they need:

Requirement	Minimum version
glibc	≥ 2.36 (Debian 12 / Ubuntu 22.04 / Fedora 37 era or newer)
Qt6 Widgets	≥ 6.4
ALSA	libasound2 + alsa-utils
JACK (optional)	any libjack — only for JACK routing

On older systems (e.g. RHEL 8's glibc 2.28) the prebuilt binaries won't run — use ./install.sh --from-source, which builds against your own libraries.

Build

cmake -B build
cmake --build build

Binaries land in build/: audio-gui, pa-alsa-bridge, and (if libjack is present) pulse-jack-bridge. The GUI launches the bridges from alongside its own executable, so keep them in the same directory.

Dependencies

	Packages (Debian/Ubuntu names)
Build	cmake, pkg-config, qt6-base-dev, libasound2-dev, libjack-jackd2-dev (optional, for JACK routing)
Runtime	libasound2, alsa-utils, Qt6 Widgets runtime; jackd2/libjack only for JACK mode

If libjack is missing at build time, pulse-jack-bridge is skipped and the GUI keeps the JACK option disabled.

Creating a release

./release-tarball.sh          # version read from the VERSION file
./release-tarball.sh 0.2.0    # or override it for a one-off build

This builds in Release mode and produces audio-gui-<version>.tar.gz (prebuilt binaries + bundled source + install.sh/uninstall.sh) that unpacks to a single Audio-Gui/ directory. Bump VERSION when cutting a release. For the widest compatibility, run it on the oldest system you support (the project ships releases built on Debian 12) so the binaries' glibc/Qt6 floor stays low.

Run

./build/audio-gui

Run as a normal user — no root required.