ferraus generate tone

Generate a test tone or sweep

Synopsis

ferraus generate tone [options]

Writes a sine, square, saw, or triangle tone (band-limited with polyBLEP, so square, saw, and triangle have no aliasing to speak of), optionally sweeping between two frequencies. The phase is accumulated in double precision, so the frequency is exact. The sample rate and channel count come from the global --sample-rate (default 48000) and --channels (default 1). Without -o the file is tone.wav in the current directory.

Examples

Five seconds of A440 at -3 dBFS

ferraus generate tone -o a440.wav

A ten-second logarithmic sweep at 96 kHz

ferraus generate tone --sweep 20Hz..20kHz --dur 10s --sample-rate 96000 -o sweep.wav

A band-limited saw at C3

ferraus generate tone --shape saw --freq C3 --dur 2s -o saw.wav

Options

Flag	Type	Default	Meaning
`--freq`	frequency	`440Hz`	Frequency (Hz, kHz, or a note such as A4)
`--dur`	time	`5s`	Duration
`--shape`	sine \| square \| saw \| triangle	`sine`	Waveform
`--sweep`	text	—	Sweep from low to high over the duration, e.g. 20Hz..20kHz (overrides --freq)
`--sweep-curve`	log \| linear	`log`	Sweep spacing: logarithmic (equal time per octave) or linear
`--amplitude`	gain	`-3dB`	Peak level in dBFS

Global options

Every command also accepts the global options (-o, --json, --dry-run, --overwrite, --progress, ...). See Global options.

Exit codes

Code	Meaning
0	Success
1	Processing failed
2	Usage or parameter error
3	Input missing or unreadable
8	Cancelled
70	Internal error (bug)

Common mistakes

Beat-based times (4b, 1/4) need a tempo: pass --bpm or write 4b@120.
Gains need a unit when not in dB: 0.5x is a factor, -6 and -6dB are decibels.

For models

MCP tool: ferraus_generate_tone
Schema: ferraus schema generate tone
Pipeline: { op: generate tone, args: { ... } } (flag names with _ instead of -)
fx stage: no

{"command": "generate tone", "defaults": {"freq": "440Hz", "dur": "5s", "shape": "sine", "sweep_curve": "log", "amplitude": "-3dB"}}