Afade

Audio Single output Transform

Fade in/out input audio.

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

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

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

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
type	AfadeType	in	in, out	set the fade direction
start_sample	int	0	≥ 0	set number of first sample to start fading
nb_samples	int	44100	≥ 1	set number of samples for fade duration
start_time	int	0	≥ 0	set time to start fading
duration	int	0	≥ 0	set fade duration
curve	AfadeCurve	tri	nofade, tri, qsin, esin, hsin, log, ipar, qua, …	set fade curve type
silence	float	0	0–1	set the silence gain
unity	float	1	0–1	set the unity gain

FFmpeg also names these options (use the parameter shown above): t → type, ss → start_sample, ns → nb_samples, st → start_time, d → duration, c → curve.

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