Chromanr

Video Single output Transform

Reduce chrominance noise.

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

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

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

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
thres	float	30	1–200	set y+u+v threshold
sizew	int	5	1–100	set horizontal patch size
sizeh	int	5	1–100	set vertical patch size
stepw	int	1	1–50	set horizontal step
steph	int	1	1–50	set vertical step
threy	float	200	1–200	set y threshold
threu	float	200	1–200	set u threshold
threv	float	200	1–200	set v threshold
distance	ChromanrDistance	manhattan	manhattan, euclidean	set distance type

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