Amix

Audio Single output Transform

Audio mixing.

FFmpeg filter: amix — 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   = $audio->addFilter(new Amix(…), [$other]);
$result = $node->outputs()[0];

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

$result = $audio->apply(new Amix(…), $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
inputs	int	2	1–32767	Number of inputs.
duration	AmixDuration	longest	longest, shortest, first	How to determine the end-of-stream.
dropout_transition	float	2	≥ 0	Transition time, in seconds, for volume renormalization when an input stream ends.
weights	string	1 1	—	Set weight for each input.
normalize	bool	true	—	Scale inputs

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