Showspectrum

Audio Video Single output Transform

Convert input audio to a spectrum video output.

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

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

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

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
slide	ShowspectrumSlide	replace	replace, scroll, fullframe, rscroll, lreplace	set sliding mode
mode	ShowspectrumMode	combined	combined, separate	set channel display mode
color	ShowspectrumColor	channel	channel, intensity, rainbow, moreland, nebulae, fire, fiery, fruit, …	set channel coloring
scale	ShowspectrumScale	sqrt	lin, sqrt, cbrt, log, 4thrt, 5thrt	set display scale
fscale	ShowspectrumFscale	lin	lin, log	set frequency scale
saturation	float	1	-10–10	color saturation multiplier
win_func	ShowspectrumWinFunc	hanning	rect, bartlett, hanning, hamming, blackman, welch, flattop, bharris, …	set window function
orientation	ShowspectrumOrientation	vertical	vertical, horizontal	set orientation
overlap	float	0	0–1	set window overlap
gain	float	1	0–128	set scale gain
data	ShowspectrumData	magnitude	magnitude, phase, uphase	set data mode
rotation	float	0	-1–1	color rotation
start	int	0	≥ 0	start frequency
stop	int	0	≥ 0	stop frequency
fps	string	auto	—	set video rate
legend	bool	false	—	draw legend
drange	float	120	10–200	set dynamic range in dBFS
limit	float	0	-100–100	set upper limit in dBFS
opacity	float	1	0–10	set opacity strength

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

---

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