The FFmpeg documentation for the afftdn audio filter says for the
Start or stop measuring noise profile. Syntax for the command is : "start" or "stop" string. After measuring noise profile is stopped it will be automatically applied in filtering.
It's a little unclear as to the basic implementation of the start/stop values in the sample_noise -sn flag. I tried:
ffmpeg -i inputfile.wav -af afftdn=nt=c:bn=sn=start=0=stop=1 noiseout.wav
as an attempt to sample the first second of sound as a noise profile, which errors with
[afftdn @ 0x7fefbb800000] Custom band noise must be integer.
So the questions are:
What's the correct input format for sample_noise?
Is there a way to sample the noise from a noise reference
.wavfile that I have, e.g.