Units and parsing
Every value on the command line, in fx strings, in pipeline files, and in MCP arguments is
parsed by the same unit parser, so 1.5s, -6dB, C4, and 1/8T mean the same thing
everywhere.
Time
| You write | Meaning |
|---|---|
1.5s, 1500ms, 2 | seconds (a bare number is seconds) |
01:23.5, 1:02:03.250 | mm:ss.fff and hh:mm:ss.fff |
44100smp | samples |
4b, 4b@120 | beats at the detected or --bpm tempo, or at an explicit tempo |
-10s | 10 seconds before the end |
start, end | the ends of the input |
Ranges use ..: --range 0s..2s, --range 1:00..end, --range ..30s (from the start),
--range -10s..end (the last ten seconds). In a beat range, give the tempo once with
--bpm 120 --range 0b..4b; an @120 suffix applies only to the end it is written on.
Gain
-6dB, +3dB, -6 (dB), 0.5x (a linear factor), -14LUFS (integrated loudness, for
normalize and mastering targets), -1dBTP (true peak, measured with 4x oversampling).
Frequency and pitch
120Hz, 2.5kHz, note names C4 (middle C, 261.63 Hz), A#3, Bb2, MIDI numbers
midi:60. Pitch offsets: 20cents, +200cents, 2st (semitones).
Ratios and percentages
4:1 or 4. 80% or the fraction 0.8; 130% is 1.3. A bare number is a fraction, so
80 means 8000%, not 80%: always write the %.
Musical grid
1/16, 1/8T (triplet: two thirds of an eighth), 1/8D (dotted: one and a half eighths).
Delay times also accept grids (--time 1/4), resolved against --bpm or the detected tempo.
Sizes and bitrates
2GB, 512MB; 192k, 320kbps.
When parsing fails
You get exit code 2 and a message naming the flag, the value, and what was expected:
error: --threshold: cannot parse gain 'loud': expected a number with dB, x, LUFS, or dBTP