How to use af=alatency in mpv player and check if it's applied?

[NeilTohno]

latency, alatency

Measure filtering latency.

Report previous filter filtering latency, delay in number of audio samples for audio filters or number of video frames for video filters.

On end of input stream, filter will report min and max measured latency for previous running filter in filtergraph.

I found no conclusion (af=alatency) in the logs.
Thanks

[richardpl]

Filter is not changing anything in its output its just reporting some numbers that for ordinary average users are irrelevant. No it does not measure A-V latency difference at all.