Aecho

Audio Single output Transform

Add echoing to the audio.

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

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

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

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
in_gain	float	0.6	0–1	set signal input gain
out_gain	float	0.3	0–1	set signal output gain
delays	string	1000	—	set list of signal delays
decays	string	0.5	—	set list of signal decays

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