[Pd] Complex audio signals

[Chuckk Hubbard]

On 6/20/06, Georg Holzmann <grhPD at gmx.at> wrote:
> Hallo!
>
> >> Using [rfft~] you can process real signals only...
> >
> > I meant like:
> > [readsf~] (for instance)
> > |
> > [rfft~]
> > |      |
> > [ifft~]  [num\ [num\
> > |   |     |         |
> > [czero~]
> > |
> > [dac~]
>
>
> hm - why do you use [rfft~] - [ifft~] ?
> THis will give you the same signal as bevor (well, you would have to
> scale it by 1/blocksize somewhere) and the imaginary part will be 0 ...

Nope, it changes the signal.  The imaginary part is wildly distorted,
and the scaling seems to depend on the frequency of the input.

>
> [rfft~] is the same as [fft~] with 0 to the imaginary input - but
> [rfft~] should be faster than [fft~] ...

There seems to be a slight difference between [rfft~] and [fft~] with
0 imaginary input though.  I don't know if it matters.

-Chuckk

>
> LG
> Georg
>


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