Decimate

Video Single output Transform

Decimate frames (post field matching filter).

FFmpeg filter: decimate — the official reference.

Add it to a graph. The explicit form works for every filter — bind it to its inputs and read the result from outputs():

$node   = $video->addFilter(new Decimate(…), [$other]);
$result = $node->outputs()[0];

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

$result = $video->apply(new Decimate(…), $other);

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
cycle	int	5	2–25	set the number of frame from which one will be dropped
dupthresh	float	1.1	0–100	set duplicate threshold
scthresh	float	15	0–100	set scene change threshold
blockx	int	32	4–512	set the size of the x-axis blocks used during metric calculations
blocky	int	32	4–512	set the size of the y-axis blocks used during metric calculations
ppsrc	bool	false	—	mark main input as a pre-processed input and activate clean source input stream
chroma	bool	true	—	set whether or not chroma is considered in the metric calculations
mixed	bool	false	—	set whether or not the input only partially contains content to be decimated

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