Avsynctest

Audio Video Multiple outputs Source

Generate an Audio Video Sync Test.

FFmpeg filter: avsynctest — the official reference.

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

$video = \FFmpeg\VideoStream::generate(new Avsynctest(…));

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
size	string	hd720	—	set frame size
framerate	string	30	—	set frame rate
samplerate	int	44100	8000–384000	set sample rate
amplitude	float	0.7	0–1	set beep amplitude
period	int	3	1–99	set beep period
delay	int	0	-30–30	set flash delay
cycle	bool	false	—	set delay cycle
duration	int	0	≥ 0	set duration
fg	string	white	—	set foreground color
bg	string	black	—	set background color
ag	string	gray	—	set additional color

FFmpeg also names these options (use the parameter shown above): s → size, fr → framerate, sr → samplerate, a → amplitude, p → period, dl → delay, c → cycle, d → duration.

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