Chromakey

Video Single output Transform

Turns a certain color into transparency. Operates on YUV colors.

FFmpeg filter: chromakey — 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   = $video->addFilter(new Chromakey(…));
$result = $node->outputs()[0];

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

$result = $video->apply(new Chromakey(…));

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
color	string	black	—	set the chromakey key color
similarity	float	0.01	1.0E-5–1	set the chromakey similarity value
blend	float	0	0–1	set the chromakey key blend value
yuv	bool	false	—	color parameter is in yuv instead of rgb

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