Firequalizer

Audio Single output Transform

Finite Impulse Response Equalizer.

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

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

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

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
gain	string	gain_interpolate(f)	—	set gain curve
gain_entry	string	—	—	set gain entry
delay	float	0.01	≥ 0	set delay
accuracy	float	5	≥ 0	set accuracy
wfunc	FirequalizerWfunc	hann	rectangular, hann, hamming, blackman, nuttall3, mnuttall3, nuttall, bnuttall, …	set window function
fixed	bool	false	—	set fixed frame samples
multi	bool	false	—	set multi channels mode
zero_phase	bool	false	—	set zero phase mode
scale	FirequalizerScale	linlog	linlin, linlog, loglin, loglog	set gain scale
dumpfile	string	—	—	set dump file
dumpscale	FirequalizerScale	linlog	linlin, linlog, loglin, loglog	set dump scale
fft2	bool	false	—	set 2-channels fft
min_phase	bool	false	—	set minimum phase mode

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