Showcwt

Audio Video Single output Transform

Convert input audio to a CWT (Continuous Wavelet Transform) spectrum video output.

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

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

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

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
size	string	640x512	—	set video size
rate	string	25	—	set video rate
scale	ShowcwtScale	linear	linear, log, bark, mel, erbs, sqrt, cbrt, qdrt, …	set frequency scale
iscale	ShowcwtIscale	log	linear, log, sqrt, cbrt, qdrt	set intensity scale
min	float	20	1–192000	set minimum frequency
max	float	20000	1–192000	set maximum frequency
imin	float	0	0–1	set minimum intensity
imax	float	1	0–1	set maximum intensity
logb	float	0.0001	0–1	set logarithmic basis
deviation	float	1	0–100	set frequency deviation
pps	int	64	1–1024	set pixels per second
mode	ShowcwtMode	magnitude	magnitude, phase, magphase, channel, stereo	set output mode
slide	ShowcwtSlide	replace	replace, scroll, frame	set slide mode
direction	ShowcwtDirection	lr	lr, rl, ud, du	set direction mode
bar	float	0	0–1	set bargraph ratio
rotation	float	0	-1–1	set color rotation

FFmpeg also names these options (use the parameter shown above): s → size, r → rate.

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