spectrust

A terminal audio spectrum analyzer written in Rust. Visualizes PCM audio in real time using block characters — reads from PipeWire, a file, or stdin.

▁▂▃▄▅▆▇█▇▆▅▄▃▂▁▁▂▃▄▅▆▇█▇▆▅▄▃▂▁▁▂▃▄▅▆▇█

Installation

Arch Linux (AUR)

yay -S spectrust

From source

cargo install --path .

Requires Rust 1.70+. PipeWire (pw-record) is only needed for the -p capture mode.

Usage

spectrust [OPTIONS]

Option	Default	Description
-f, --fps <N>	60	Target frames per second
-p, --pipewire	—	Capture audio directly from PipeWire
-i, --input <FILE>	—	Read PCM from a file (stdin if omitted)
-l, --log-power <N>	1.4	Frequency scaling power (0.5–3.0); higher values give more space to bass
-d, --drop-off <N>	0.75	Bar drop-off factor per frame (0.0 = instant, 1.0 = no drop)
--rate <HZ>	48000	Sample rate — must match the audio source
--channels <N>	2	Channel count — must match the audio source

Input modes

PipeWire — capture system audio directly:

spectrust -p

stdin — pipe from any recorder:

pw-record --format=s16 --rate=48000 --channels=2 --raw - | spectrust
arecord -f S16_LE -r 48000 -c 2 | spectrust

File — replay a raw PCM file:

spectrust -i recording.pcm

Runtime controls

Key	Action
q / Ctrl+C	Quit
[ / ]	Decrease / increase drop-off speed
, / .	Decrease / increase log frequency scaling
- / +	Decrease / increase sensitivity

Notes

• Input is expected as signed 16-bit little-endian PCM (s16le). This matches pw-record --format=s16 --raw and arecord -f S16_LE.
• If --rate or --channels don't match the actual source the visualization will be distorted.
• The sensitivity control scales bar heights at render time; it has the most noticeable effect on quiet signals.

License

MIT