rsc3/doc-schelp/HelpSource/Classes/PV_JensenAndersen.scrbl

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2022-08-24 13:53:18 +00:00
#lang scribble/manual
@(require (for-label racket))
@title{PV_JensenAndersen}
FFT feature detector for onset detection.@section{related}
Classes/PV_HainsworthFoote
@section{categories}
UGens>FFT
@section{description}
FFT feature detector for onset detection based on work described in
emphasis::
Jensen, K. & Andersen, T. H. (2003). Real-time Beat Estimation
Using Feature Extraction. In Proceedings of the Computer Music Modeling
and Retrieval Symposium, Lecture Notes in Computer Science. Springer
Verlag.
::
First order derivatives of the features are taken.
@racketblock[threshold:: may need to be set low to pick up on
changes.
]
@section{classmethods}
@section{private}
categories
@section{method}
ar
@section{argument}
buffer
FFT buffer.
@section{argument}
propsc
Proportion of spectral centroid feature.
@section{argument}
prophfe
Proportion of high frequency energy feature.
@section{argument}
prophfc
Proportion of high frequency content feature.
@section{argument}
propsf
Proportion of spectral flux feature.
@section{argument}
threshold
Threshold level for allowing a detection.
@section{argument}
waittime
If triggered, minimum wait until a further frame can cause
another spot (useful to stop multiple detects on heavy signals).
@section{Examples}
@racketblock[
(
SynthDef(\fftod, { var source1, detect;
source1 = AudioIn.ar(1);
detect = PV_JensenAndersen.ar(FFT(LocalBuf(2048), source1),
threshold:MouseX.kr(0.1,1.0));
Out.ar(0, SinOsc.ar([440,445], 0, Decay.ar(0.1*detect, 0.1)));
}).play(s);
)
::
]