Acrossfade

Audio Single output Transform

Cross fade two input audio streams.

FFmpeg filter: acrossfade — the official reference.

Add it to a graph. The explicit form works for every filter — bind it to its inputs and read the result from outputs():

$node   = $audio->addFilter(new Acrossfade(…), [$other]);
$result = $node->outputs()[0];

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

$result = $audio->apply(new Acrossfade(…), $other);

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
nb_samples	int	44100	1–214748364	set number of samples for cross fade duration
duration	int	0	0–60000000	set cross fade duration
overlap	bool	true	—	overlap 1st stream end with 2nd stream start
curve1	AcrossfadeCurve	tri	nofade, tri, qsin, esin, hsin, log, ipar, qua, …	set fade curve type for 1st stream
curve2	AcrossfadeCurve	tri	nofade, tri, qsin, esin, hsin, log, ipar, qua, …	set fade curve type for 2nd stream

FFmpeg also names these options (use the parameter shown above): ns → nb_samples, d → duration, o → overlap, c1 → curve1, c2 → curve2.

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