Re: [LAD] FFT 1D real

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To: <linux-audio-dev@...>
Date: Monday, March 14, 2011 - 7:50 pm

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Cit=C4=93jot *Fons Adriaensen [1]*:

What is good/best way to calculate values for visual 10-20 hopping
bars like in GUI audio players ?
Can U gimme pointers to such functions ?
What about all Radix algorithms ?
Tnx in advance
Alf
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Cit=C4=93jot Fons Adriaensen <fons@linuxaudio.org>: > How from ...1024 or 2048 or 4096... FFT return values i =
calculate > power magnitudes for all bands, > and fin=
ally values for visual 10-20 hopping bars, like in Winamp , > XM=
MS , QMMP ... ? If you want such a display the FFT is not =
a good way to do it. It's possible but not simple if you want a cor=
rect result. What is good/best way to calculate v=
alues for visual 10-20 hopping bars like in GUI audio players ? > 43303.2715 + 796.7285 =
=3D 44100 or 44100 - 43303.2715 =3D 796.7285> > Why Frequency=
796.7285 is mirrored as Frequency 43303.2715 , and magnitude for both Freq=
uencies is divided by 2 ???? Because you are using a compl=
ex FFT, and the imaginary part of your signal is zero. That means t=
hat the spectrum must be symmetric. > Is here w=
ay direct calculate full magnitude and without Frequency > mirro=
ring , in band 0 Hz ... FSampl/2 ONLY , Use an FFT operati=
ng on real data instead of complex. Can U gimme pointer=
s to such functions ?What about all Radix algorithms ? <=
br /> Tnx in advance Alf   ---------- P=C4=81rs=C5=ABt=C4=ABt=C4=81s =
v=C4=93stules beigas ----------  

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Messages in current thread:
Re: [LAD] FFT 1D real, Alfs Kurmis, (Mon Mar 14, 7:50 pm)
Re: [LAD] FFT 1D real, Fons Adriaensen, (Mon Mar 14, 9:21 pm)