Afftfilt

Audio Single output Transform

Apply arbitrary expressions to samples in frequency domain.

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

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

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

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
real	string	re	—	set channels real expressions
imag	string	im	—	set channels imaginary expressions
win_size	int	4096	16–131072	set window size
win_func	AfftfiltWinFunc	hanning	rect, bartlett, hanning, hamming, blackman, welch, flattop, bharris, …	set window function
overlap	float	0.75	0–1	set window overlap

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