A lightweight audio visualizer for Windows. Captures desktop audio (or a microphone/other input device) via WASAPI and renders it in real time. Works as a normal window or as a click-through overlay.
- Audio source picker: Default Output (WASAPI loopback) or any capture device, selectable from the settings panel.
- 13 visualizer styles: Bars, Wave, Circular Wave, Cubes, Fire, Gauge, Kenwood Bars, LED Panel, Matrix LED, Particles, Sunburst (Polyline Wave), Sphere, Waterfall.
- Overlay mode: Transparent, borderless, click-through window that stays on top.
- Settings panel: ImGui window for renderer, FFT window, bar count, amplification, smoothing, primary color, and overlay toggle.
- Rendering: Blend2D (software, on D3D11 swapchain) for the visualization; ImGui/D3D11 for the settings panel.
Active only while the main window or settings panel has focus (overlay toggle works globally).
| Key | Action |
|---|---|
| Space | Start / Stop audio capture |
| O | Toggle Overlay Mode |
| R | Switch to the next visualizer style |
| Q | Cycle through render qualities |
| Up / Down | Increase / Decrease amplification |
| Left / Right | Change FFT window |
| - / + | Decrease / Increase bar count |
| ESC | Exit the app (or exit overlay mode) |
- Audio Source: Defaults to WASAPI loopback of the default playback device. To visualize a microphone or another input, open the settings panel (click the "Show Settings" button in the top-right corner) and pick a device under Audio → Audio Source.
- Overlay Performance: In overlay mode, frame rate can drop when a fullscreen application has focus — this is a Windows compositor limitation, not a bug.
Requirements:
- Windows 10/11 (x64)
- Visual Studio 2019/2022 with "Desktop development with C++"
- CMake 3.20+
- Git (dependencies are fetched into
third_party/on first configure)
Steps:
- Clone the repository.
- Configure with CMake (e.g. open the folder in Visual Studio, or run
cmake -B build -S .). - Build the
SpectrumCpptarget in Release x64.
The executable is placed under build/bin/<Config>/SpectrumCpp.exe.
MIT License. See LICENSE.txt.