Anoisesrc

Audio Single output Source

Generate a noise audio signal.

FFmpeg filter: anoisesrc — the official reference.

Generate a stream. Anoisesrc is a source — it has no input, so you create a stream from it rather than applying it to one:

$audio = \FFmpeg\AudioStream::generate(new Anoisesrc(…));

apply() and addFilter() do not apply to source filters (there is nothing to attach them to).

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
sample_rate	int	48000	≥ 15	set sample rate
amplitude	float	1	0–1	set amplitude
duration	int	0	≥ 0	set duration
colour	AnoisesrcColor	white	white, pink, brown, blue, violet, velvet	set noise color
seed	int	-1	≥ -1	set random seed
nb_samples	int	1024	≥ 1	set the number of samples per requested frame
density	float	0.05	0–1	set density

FFmpeg also names these options (use the parameter shown above): r → sample_rate, a → amplitude, d → duration, color → colour, c → colour, s → seed, n → nb_samples.

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