Acrusher

Audio Single output Transform

Reduce audio bit resolution.

FFmpeg filter: acrusher — 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 Acrusher(…));
$result = $node->outputs()[0];

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

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

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
bits	float	8	1–64	set bit reduction
mix	float	0.5	0–1	set mix
mode	AcrusherMode	lin	lin, log	set mode
dc	float	1	0.25–4	set DC
aa	float	0.5	0–1	set anti-aliasing
samples	float	1	1–250	set sample reduction
lfo	bool	false	—	enable LFO
lforange	float	20	1–250	set LFO depth
lforate	float	0.3	0.01–200	set LFO rate

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