Levels & Files

The methods named here are in the audio reference.

Volume

Fact	Value
Unit	dB. 0 is unity gain.
Range	−70 to +6. −70 and below is silence; above +6 is held at +6.
set_norm(0…1)	0 is −70 dB, 1 is +6 dB, linear in dB between
A new value	Glides there over 10 ms
From a signal	The signal’s value in dB

Pan

Fact	Value
Range	−1 (left) to 1 (right); 0 is centre
Law	Constant power: θ = (pan + 1)·π/4, left gain √2·cos θ, right gain √2·sin θ
Centre	Both channels at unity, exactly
Hard left or right	That side +3 dB, the other side silent
A stereo track	Each channel is scaled by its gain: the pan acts as a balance
A mono sample	Played on both channels, then panned

Audio device

Fact	Value
Sample rate	The device’s own, unless sample_rate is set in preferences; 48000 if the device does not say
Buffer size	The device’s own, unless buffer_size is set; at most 4096 frames

Audio files

File	Format
A sample, a kit sound	WAV, integer or float, any bit depth, sample rate or channel count. No other format is read.
render output	WAV, stereo, 48000 Hz, 24-bit integer, whatever the device’s rate. Samples beyond ±1 are clipped; no dither.
track.save, clip.save	WAV, 32-bit float, at the clip’s own sample rate and channel count

A render is cycles cycles long, exactly: floor(48000 / cps) × cycles frames. It goes to a new folder:

renders/<name>_<YYYY-MM-DD>_<HH-MM-SS>/
├── master.wav          render(n), render(master, n)
├── <track>.wav         render(track, n), one per track rendered
└── frames/             render(screen, n): frame_00000.png onwards, 60 a second

<name> is the project’s set_project_title, else its package name, else untitled — lower-cased, with every character other than a letter, digit or - made _, runs of _ made one, _ trimmed from both ends, and cut to 50 characters. How to render is in Render a Project.

What a render contains

A render runs the session’s audio graph offline, from cycle 0, whatever the play head is doing. It works in a file run and in a live session, where live output pauses while it runs.

File	What is in it
master.wav	Every audio track that reaches the master: instruments, effects, faders, sends, buses, the master’s effects, modulation and automation, with plugin latency compensated
<track>.wav	The track alone: its instrument, effects and fader. Its buses, its sends and the master’s effects are not in it.

Not in a render:

MIDI tracks	A WAV holds audio. midi_export() writes their notes.
A track sent to hardware outputs	Not in master.wav, as it is not in the master live. Its own <track>.wav has it.
A track’s .set_delay()	The round trip to outboard gear is not there to compensate, and the delay is not applied.
Live inputs	A track’s set_input() is silent.
The tail	The render stops at its last cycle; a reverb or delay still sounding is cut.

Effects are not cleared first: in a live session, a delay or reverb still sounding carries it into the render’s first cycle. rand_true() and choose_true() give a new value every call, in a render too, so a render that uses them differs every time; seeded rand() and choose() do not.

save_project

save_project() writes the state of every CLAP and VST3 plugin in the session to the project’s plugin-state/ folder, and load_project() reads it back.

plugin-state/
├── track__<track>__instrument.preset
├── track__<track>__effect__<slot>.preset
├── master__effect__<slot>.preset
└── .history/
    └── <YYYY-MM-DD_HH-MM-SS-mmm>/     a copy of each save, the last 100

Names are made safe for a file name. When two plugins’ names would give one file name, a 6-digit hexadecimal hash is added (__h1a2b3c). A .preset file of a plugin no longer in the session is removed at the next save.

A .preset file is JSON:

Key	Value
resonon_preset	1, the format version
plugin_name	The plugin’s name
state.params	Each parameter’s value, by its path
state.binary_state	The plugin’s own saved state, base64, when it has one