Afwtdn

Audio Single output Transform

Denoise audio stream using Wavelets.

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

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

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

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
sigma	float	0	0–1	set noise sigma
levels	int	10	1–12	set number of wavelet levels
wavet	AfwtdnWavet	sym10	sym2, sym4, rbior68, deb10, sym10, coif5, bl3	set wavelet type
percent	float	85	0–100	set percent of full denoising
profile	bool	false	—	profile noise
adaptive	bool	false	—	adaptive profiling of noise
samples	int	8192	512–65536	set frame size in number of samples
softness	float	1	0–10	set thresholding softness

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