Aiir

Audio Multiple outputs Transform

Apply Infinite Impulse Response filter with supplied coefficients.

FFmpeg filter: aiir — 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():

$outputs = $audio->addFilter(new Aiir(…))->outputs(); // one stream per output pad

Shorthand. Not available — apply() returns a single stream, and Aiir has multiple outputs. Use addFilter() + outputs() above.

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
zeros	string	1+0i 1-0i	—	set B/numerator/zeros/reflection coefficients
poles	string	1+0i 1-0i	—	set A/denominator/poles/ladder coefficients
gains	string	1|1	—	set channels gains
dry	float	1	0–1	set dry gain
wet	float	1	0–1	set wet gain
format	AiirFormat	zp	ll, sf, tf, zp, pr, pd, sp	set coefficients format
process	AiirProcess	s	d, s, p	set kind of processing
precision	AiirPrecision	dbl	dbl, flt, i32, i16	set filtering precision
normalize	bool	true	—	normalize coefficients
mix	float	1	0–1	set mix
response	bool	false	—	show IR frequency response
channel	int	0	0–1024	set IR channel to display frequency response
size	string	hd720	—	set video size
rate	string	25	—	set video rate

FFmpeg also names these options (use the parameter shown above): z → zeros, p → poles, k → gains, f → format, r → process, e → precision, n → normalize.

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