[FFmpeg-user] down sampling

Michael Koch astroelectronic at t-online.de
Sun Dec 30 14:10:05 EET 2018

Am 28.12.2018 um 11:46 schrieb Paul B Mahol:
> One can now use afftfilt to shift frequencies around in frequency domain. 
> It should be easier than using amultiply filter.

c:\ffmpeg\ffmpeg -f dshow -channels 2 -i audio="Mikrofon (Realtek High 
Definiti" -af 
volume=30,afftfilt='real=real(b+300,ch)':'imag=imag(b+300,ch)' -f nut - 
| c:\\ffmpeg\ffplay -

I've just tested this and it works fine. There is no error message when 
(b+300) becomes larger than the available number of bins. How does 
afftfilt handle this case?
Does real(too_large_number,ch) return zero?


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