pub const VIBRATO_CONVENTION: &str = "the voiced f0 frames of a steady span, a voiced run of \
the track split where two stable pitches lie 150 cents or more apart, without 50 ms at each end, \
without the frames where a glide's fitted curve lies more than 10 cents from both its pitches \
and without a drop: the span before it ends 50 ms before its onset, and the span after starts \
once it has settled, five time constants and at least 100 ms after the onset; in cents; start_s and end_s are its first and last frame in audio time; a least-squares line and sine fitted \
together, at the rate whose sine explains the most power beyond the line, searched from 1 Hz or \
1.5 cycles over the span up to 20 Hz in 0.01 Hz steps and refined by golden-section search; extent_raw_ct is that sine's amplitude, half the peak-to-peak swing; extent_ct is \
extent_raw_ct times extent_factor, which undoes the smoothing of the f0 track at that rate; a \
vibrato counts at 2.97 to 12.12 Hz, 3 to 12 Hz with 1 % slack, with extent_ct of 10 or more and a share, the power the sine \
explains beyond the line, the line's residual less that of the line and sine together, over the \
power left after the line alone, of 0.5 or more, over 2.5 cycles or more";Expand description
The convention of a vibrato, as layers.json names it.