Colorlevels

Video Single output Transform

Adjust the color levels.

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

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

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

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
rimin	float	0	-1–1	set input red black point
gimin	float	0	-1–1	set input green black point
bimin	float	0	-1–1	set input blue black point
aimin	float	0	-1–1	set input alpha black point
rimax	float	1	-1–1	set input red white point
gimax	float	1	-1–1	set input green white point
bimax	float	1	-1–1	set input blue white point
aimax	float	1	-1–1	set input alpha white point
romin	float	0	0–1	set output red black point
gomin	float	0	0–1	set output green black point
bomin	float	0	0–1	set output blue black point
aomin	float	0	0–1	set output alpha black point
romax	float	1	0–1	set output red white point
gomax	float	1	0–1	set output green white point
bomax	float	1	0–1	set output blue white point
aomax	float	1	0–1	set output alpha white point
preserve	ColorlevelsPreserve	none	none, lum, max, avg, sum, nrm, pwr	set preserve color mode

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