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

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>    > How from ...1024 or 2048 or 4096... FFT return values i

> calculate

>    > power magnitudes for all bands,

>    > and finally values for visual 10-20 hopping bars, like in

> Winamp ,

>    > XMMS , QMMP ... ?

>=20

>    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 correct result.

  What is good/best way to calculate values for visual 10-20 hopping

 bars like in GUI audio players ?

quoted text
>    > 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 Frequencies is divided by 2 ????

>=20

>    Because you are using a complex FFT, and the imaginary part

>    of your signal is zero. That means that the spectrum must be

>    symmetric.

>=20

>    > Is here way direct calculate full magnitude and without

> Frequency

>    > mirroring , in band 0 Hz ... FSampl/2 ONLY ,

>=20

>    Use an FFT operating on real data instead of complex.

  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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