Crossfeed

Audio Single output Transform

Apply headphone crossfeed filter.

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

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

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

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
strength	float	0.2	0–1	set crossfeed strength
range	float	0.5	0–1	set soundstage wideness
slope	float	0.5	0.01–1	set curve slope
level_in	float	0.9	0–1	set level in
level_out	float	1	0–1	set level out
block_size	int	0	0–32768	set the block size

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