SuperCollider CLASSES

PV_JensenAndersen

FFT feature detector for onset detection.

Description

FFT feature detector for onset detection based on work described in 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. threshold may need to be set low to pick up on changes.

Class Methods

*ar (buffer, propsc: 0.25, prophfe: 0.25, prophfc: 0.25, propsf: 0.25, threshold: 1, waittime: 0.04)

Arguments:

buffer

FFT buffer.

propsc

Proportion of spectral centroid feature.

prophfe

Proportion of high frequency energy feature.

prophfc

Proportion of high frequency content feature.

propsf

Proportion of spectral flux feature.

threshold

Threshold level for allowing a detection.

waittime

If triggered, minimum wait until a further frame can cause another spot (useful to stop multiple detects on heavy signals).

Inherited class methods

Instance Methods

Inherited instance methods

Examples

(
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);
)