vu(...) --- Level Meters
vu() shows how loud things are: the whole mix, left and right, or a bar
for each sound named. It is for seeing a sound you cannot hear yet, a
balance between sounds, and above all clipping -- a mix over full scale,
heard as crackle, and recorded that way by capture().
Syntax
vu() vu(NAME, NAME, ...) vu(all) vu(master, NAME) vu(NAME, stereo) a pair of bars, left and right vu(all, stereo) synth(uid:NAME, ..., vu:stereo) that sound a pair wherever it is metered vu(stop)
Parameters
| param | required | description |
|---|---|---|
| bare names | ✖ | What to meter: a sound's uid (bass), master (the whole mix: two bars, L and R) or all (every sound playing, bars coming and going with them). Without any, the mix. |
uid |
✖ | The meters' own name, vu by default. Another name makes another set: vu(drums, uid:m2). |
floor |
✖ | The bottom of the scale in dB, -60 by default. The top is +6. |
hold |
✖ | Beats the peak mark stays before it falls, 1.5 by default. |
size |
✖ | The box: [width, height] as fractions of the screen, as gui() takes it -- vu(bass, size:[0.04, 0.3]) a slim one. One number is both. |
at |
✖ | Where its centre is, [across, down] 0..1 -- at:[0.97, 0.5] at the right edge; one number is both (at:0.5). Without it the meters go at the right edge, or just left of the live console when it is open there. |
stereo |
✖ | A pair of bars, left and right, for each sound shown, its name under both: vu(s3, stereo), vu(all, stereo). Without it a sound has one bar (the mix always has two). |
stop |
✖ | Take the meters away: vu(stop) all of them, vu(uid:m2, stop:1) one set. |
Reading it
- the bar is the level (RMS): it rises at once and falls over about 0.3 s; green, then amber from -18 dB, red from -6 dB
- the line above it is the peak, held, then falling
- the number on top is the loudest peak so far, in dB; the thin line across is 0 dB, full scale
- over 0 dB the number and the peak mark turn red: that sound (or the mix) is clipping
A synth is metered at its output, after its delay and reverb; an audio file
at its gain; the mix after VOL and the limiter -- what you hear, and what
capture() records. A sound with several voices (poly:, a pool) shows
the loudest of them.
Mono and stereo
A sound has one bar by default — its left and right together. Ask for a pair where you want to see the two sides:
vu(s3, stereo) s3 as a pair vu(all, stereo) every sound as a pair synth(uid:s3, pan:-0.6, vu:stereo) s3 as a pair wherever it is metered, vu(all) too audio(uid:rain, src:rain, vu:mono) one bar, even in vu(all, stereo)
vu:stereo / vu:mono on a sound's own line (synth(), audio(), say())
wins over the meter's stereo, so in vu(all) the few that matter get
their pair and the rest stay single. A sound asked for a pair that comes out
in mono — no pan:, no reverb, a one-channel file — shows the same on both
bars. One bar of a sound panned hard to one side reads 6 dB under that
side's bar: the two sides are summed.
Behaviour
- the meters are drawn in a box like a sound's: drag it, pull its edges, or
place it with
gui():gui(vu, size:[0.2, 0.5], at:[0.9, 0.5]) - running the line again changes what it shows; the box stays where it is
hush()leaves the meters up -- silence is worth seeing- in the live console, running a commented-out
vu(...)line, orCtrl+Shift+.on it, takes the meters away
Examples
vu() the mix vu(bass, drums) two sounds side by side vu(master, all) the mix, then everything playing vu(all, floor:-48, hold:3) a tighter scale, peaks held longer gui(vu, size:[0.15, 0.6], at:[0.92, 0.5]) vu(stop)
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