Stereotools

Audio Single output Transform

Apply various stereo tools.

FFmpeg filter: stereotools — the official reference.

Add it to a graph. The explicit form works for every filter — bind it to its input and read the result from outputs():

$node   = $audio->addFilter(new Stereotools(…));
$result = $node->outputs()[0];

Shorthand. Single-output filters can skip the node — apply() returns the result stream directly:

$result = $audio->apply(new Stereotools(…));

When to use it

TODO — when this filter shines: what it’s the right tool for, what to reach for instead when it isn’t, and how it composes with neighbouring filters.

How to use it

TODO — prose: how the filter actually works and what its key parameters mean (the explanation FFmpeg’s terse option help omits).

Examples

TODO — runnable PHP, with the equivalent ffmpeg CLI alongside.

Gotchas

TODO

See also

TODO

Parameters

Parameter	Type	Default	Range / values	Description
level_in	float	1	0.015625–64	set level in
level_out	float	1	0.015625–64	set level out
balance_in	float	0	-1–1	set balance in
balance_out	float	0	-1–1	set balance out
softclip	bool	false	—	enable softclip
mutel	bool	false	—	mute L
muter	bool	false	—	mute R
phasel	bool	false	—	phase L
phaser	bool	false	—	phase R
mode	StereotoolsMode	lr>lr	lr>lr, lr>ms, ms>lr, lr>ll, lr>rr, lr>l+r, lr>rl, ms>ll, …	set stereo mode
slev	float	1	0.015625–64	set side level
sbal	float	0	-1–1	set side balance
mlev	float	1	0.015625–64	set middle level
mpan	float	0	-1–1	set middle pan
base	float	0	-1–1	set stereo base
delay	float	0	-20–20	set delay
sclevel	float	1	1–100	set S/C level
phase	float	0	0–360	set stereo phase
bmode_in	StereotoolsBmode	balance	balance, amplitude, power	set balance in mode
bmode_out	StereotoolsBmode	balance	balance, amplitude, power	set balance out mode

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Maps to FFmpeg’s stereotools filter. Verified against ffmpeg n7.1.1.