Smartblur

Video Single output Transform

Blur the input video without impacting the outlines.

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

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

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

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
luma_radius	float	1	0.1–5	set luma radius
luma_strength	float	1	-1–1	set luma strength
luma_threshold	int	0	-30–30	set luma threshold
chroma_radius	float	-0.9	-0.9–5	set chroma radius
chroma_strength	float	-2	-2–1	set chroma strength
chroma_threshold	int	-31	-31–30	set chroma threshold
alpha_radius	float	-0.9	-0.9–5	set alpha radius
alpha_strength	float	-2	-2–1	set alpha strength
alpha_threshold	int	-31	-31–30	set alpha threshold

FFmpeg also names these options (use the parameter shown above): lr → luma_radius, ls → luma_strength, lt → luma_threshold, cr → chroma_radius, cs → chroma_strength, ct → chroma_threshold, ar → alpha_radius, as → alpha_strength, at → alpha_threshold.

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