rvsp

rvsp is a lightweight audio spectrum visualizer made in Rust, drawing inspiration from techniques used in WebAudio API. It is GPU accelerated through OpenGL (ES), supporting Linux and Raspberry PIs.

This uses PipeWire and Wayland (via winit and glutin), which is not available anywhere except Linux. Since my primary workstation is Linux, I have no plans to port it to Windows or Mac.

Installation

PipeWire development headers must be installed through the package manager of your distribution, if it packages them separately.

Git

$ sudo apt install libpipewire-0.3-dev
$ cargo install --git "https://github.com/cynthia2006/rvsp" --locked

It installs a binary rvsp in ~/.cargo/bin.

crates.io

$ cargo install rvsp

Controls

• ↑ to increase, and ↓ to decrease gain.
• ← to decrease, and → to increase smoothing time constant (0 < τ < 1).

"Suckless" Philosophy

This app has no mechanism for dynamic configuration; if you want to tweak something, you can tweak it by changing the constants defined in src/main.rs.

Suppose you want increase the bandwidth: you open src/main.rs; modify MAX_FREQ to, say, 12000.

-const MAX_FREQ: i32 = 10000;
+const MAX_FREQ: i32 = 12000;

Smoothing time constant

Smoothing time constant (τ) is a parameter that controls how data is smoothed exponentially over time; a kind of lowpass filtering. In this context, it controls the responsiveness of the spectrum—higher the values, the less it is responsive. It defaults to 0.7, which in my personal experience, provides the best experience.

Spectrum

The spectrum is linear, both on the frequency and the amplitude axis. The frequency range is limited between 50 to 10000 Hz, chiefly considering visual aesthetics. Generally speaking, you won't be interested in the higher parts of the spectrum.

To comprehend the theory that underpins the mechanics of this program, i.e. STFT (Short-Time Fourier Transform), read this guide.