75 lines
1.7 KiB
Text
75 lines
1.7 KiB
Text
|
#lang scribble/manual
|
||
|
|
@(require (for-label racket))
|
||
|
|
|
||
|
|
@title{Unpack1FFT}
|
||
|
|
Unpack a single value (magnitude or phase) from an FFT chain@section{categories}
|
||
|
|
UGens>FFT
|
||
|
|
@section{related}
|
||
|
|
Classes/PackFFT, Classes/UnpackFFT
|
||
|
|
|
||
|
|
|
||
|
|
Unpack1FFT(chain, bufsize, binindex, whichmeasure=0)
|
||
|
|
|
||
|
|
@section{description}
|
||
|
|
|
||
|
|
Takes an FFT chain and extracts a single scalar value as a demand-rate stream. To call it you need a "demander" which fires whenever the FFT chain fires - this is normally achieved using link::Classes/PackFFT:: but can also be done using link::Classes/Demand::.
|
||
|
|
|
||
|
|
@section{Note}
|
||
|
|
|
||
|
|
The main purpose of this UGen is as a component in pvcollect, pvcalc, and pvcalc2 processes. You're welcome to use it on its own - the example below shows basic usage. But most people won't typically need to use it directly.
|
||
|
|
::
|
||
|
|
|
||
|
|
@section{classmethods}
|
||
|
|
|
||
|
|
@section{private}
|
||
|
|
categories
|
||
|
|
|
||
|
|
@section{method}
|
||
|
|
new
|
||
|
|
|
||
|
|
@section{argument}
|
||
|
|
chain
|
||
|
|
an FFT chain
|
||
|
|
@section{argument}
|
||
|
|
bufsize
|
||
|
|
the size of the expected input FFT frames
|
||
|
|
@section{argument}
|
||
|
|
binindex
|
||
|
|
the integer index of the bin you want to query
|
||
|
|
@section{argument}
|
||
|
|
whichmeasure
|
||
|
|
0 for magnitude and 1 for phase. None of these arguments can be modulated.
|
||
|
|
|
||
|
|
@section{examples}
|
||
|
|
|
||
|
|
|
||
|
|
@racketblock[
|
||
|
|
(
|
||
|
|
s.waitForBoot({
|
||
|
|
c = Buffer.read(s, Platform.resourceDir +/+ "sounds/a11wlk01.wav");
|
||
|
|
})
|
||
|
|
)
|
||
|
|
|
||
|
|
// Let's extract the DC component - i.e. the magnitude at index zero.
|
||
|
|
(
|
||
|
|
x = {
|
||
|
|
var fftsize = 1024;
|
||
|
|
var sig, chain, unp;
|
||
|
|
sig = PlayBuf.ar(1, c, BufRateScale.kr(c), loop: 1);
|
||
|
|
chain = FFT(LocalBuf(fftsize), sig);
|
||
|
|
|
||
|
|
unp = Unpack1FFT(chain, b.numFrames, 0, 0);
|
||
|
|
|
||
|
|
// Demand some data from the unpacker
|
||
|
|
Demand.kr(chain>=0, 0, unp).poll(chain>=0, "unpacked value");
|
||
|
|
|
||
|
|
(sig*0.1).dup;
|
||
|
|
}.play(s);
|
||
|
|
)
|
||
|
|
x.free;
|
||
|
|
::
|
||
|
|
|
||
|
|
]
|
||
|
|
|
||
|
|
|