Prism — Real-time Audio Analysis & Metering

// Analysis

Seven analyzers. One engine.

Build a rack around the signal, not the other way around. Every analyzer is independently configurable, resizable, rotatable where supported, and available across Prism’s desktop, plugin, and terminal surfaces.

01 / FFT

Spectrum Analyzer

Calibrated dBFS levels, FFT sizes from 1024 to 16384, Log/Mel/Linear scales, spectral tilt, heatmap and fill modes, plus peak frequency and pitch readouts.

02 / Time

Oscilloscope

Stable time-domain views with fundamental-frequency pitch locking and sub-sample triggering.

03 / Phase

Vectorscope

XY, Polar, and M/S Linear stereo analysis with calibrated references and optional multiband RGB.

04 / Time × Frequency

Spectrogram

Classic and frequency-reassigned views across Log, Mel, and Linear scales with stereo-energy analysis.

05 / Ballistics

VU Meter

300 ms metering, adjustable 0 VU calibration, stereo correlation, and needle or bar displays.

06 / Loudness

Loudness Meter

ITU-R BS.1770 momentary, short-term, and integrated LUFS with true-peak activity.

07 / History

Waveform

Scrolling mono or stereo history with transient-preserving sampling and optional multiband energy. Spectrum, Spectrogram, Oscilloscope, and Waveform also provide interactive measurement overlays.

// Hosts

Desktop, plugin, and terminal.

Each host is built around the same native analysis implementations where applicable. The interface changes; the analyzer vocabulary and calibration do not.

Desktop / Windows · macOS · Linux

System and device capture

Prism captures the active system output without a virtual audio cable, or switches to a microphone, interface, or line input. Scopes can remain in the rack or run as independent popout windows.

macOS: CoreAudio Audio Hardware Taps
Windows: WASAPI loopback capture
Linux: PulseAudio monitor sources; U8, S16, S24, S32, and F32 input normalization
Device inputs: Separate low-latency AudioWorklet capture path
Clocking: Analysis follows the active device sample rate

DAW / VST3 · AU

One plugin per analyzer

All seven analyzers are available as mono or stereo pass-through plugins. Prism does not modify the host audio buffer, and analyzer state is stored with the project.

Formats: VST3 on Windows, macOS, and Linux; AU on macOS
RT callback: Copies samples into a lock-free FIFO
Analysis: FFT, loudness, and rendering work happens outside the real-time audio thread
Signal path: Pure pass-through; host audio remains unmodified
State: Scope configuration serialized into project/plugin state

Terminal / prism-tui

Native terminal interface

prism-tui uses the same analyzer and system-capture implementations in a keyboard-driven interface with live output switching, input trim, profiles, and .iro themes.

Rendering: 60 FPS default; experimental 120 FPS mode
Compatibility: 256-color mode up to 60 FPS; basic ANSI safe mode up to 30 FPS
Analysis: All seven scopes, including reassigned spectrogram and multiband modes
Memory: Approximately 35 MB in typical use

05sec10sec30sec60sec

// Rolling capture

Forgot to record that? Prism didn't.

Prism continuously retains the selected amount of PCM audio in memory. Drag the buffer out as a mono or stereo, 16-bit RIFF/WAV file without starting a recording beforehand.

Source rates to 384 kHzDirect file drag-out

// Customize

Profiles, themes, and display modes.

Prism’s neutral dark interface is the starting point, not a locked identity. Save entire workspaces as profiles and change the application and every analyzer through editable theme files.

Prism v0.3 neutral dark interface with Spectrum, Oscilloscope, and Vectorscope settings open

.prsm

Profiles

Save visible scopes, rack layout, analyzer settings, window state, and popout positions as a shareable workspace.

.iro

Themes

Edit interface, control, scope, gradient, guide, label, meter, and overlay colors in a human-readable theme file.

WINDOW

Overlays

Run the rack and popouts on solid, blurred, or clear backgrounds, then pin the scopes above the applications you use.

// Streaming

Chroma-ready when you need it.

Built-in chroma themes make it easy to key Prism’s scopes into OBS and other video workflows as clean overlays.

Prism scopes rendered against white and blue chroma backgrounds

// Technical

Pretty graphs. Serious numbers.

Prism’s visual surfaces share native analysis implementations, tested calibration behavior, and a signal path designed to keep expensive work away from real-time audio callbacks.

AnalysisNative C++ DSP shared across desktop, plugins, and terminal where applicable

SpectrumCalibrated dBFS magnitude, 1024–16384 FFT, Log/Mel/Linear scales

LoudnessITU-R BS.1770 momentary, short-term, integrated LUFS, and true peak

CaptureCoreAudio taps, WASAPI loopback, PulseAudio monitors, and device input

PluginsVST3 on Windows, macOS, and Linux; AU on macOS; mono and stereo hosts

Rendering10, 30, 60, 120, or 144 FPS, plus display-synchronized rendering

PlatformsWindows · macOS · Linux

LicenseGNU General Public License v3.0

// Download

Put Prism where you work.

Prism is free and open source. Installable packages include the desktop app and the components supported by each platform, including DAW plugins and prism-tui where applicable.

All releases ↗

⊞

Windows

Desktop · VST3 · TUI

NSIS + Portable ⌘

macOS

Desktop · VST3 · AU · TUI

PKG + ZIP ›_

Linux

Desktop · VST3 · TUI

AppImage · DEB · RPM · TAR.GZ

Build from sourcebash

git clone https://github.com/Boof2015/prism.git
cd prism
npm install          # builds the native module
npm run dev          # desktop development
npm run dist:mac     # or dist:win / dist:linux