Flux

standard mode | Spectral category

Inputs

  • spectrum (vector_real) - the input spectrum

Outputs

  • flux (real) - the spectral flux of the input spectrum

Parameters

  • halfRectify (bool ∈ {true, false}, default = false) :

    half-rectify the differences in each spectrum bin

  • norm (string ∈ {L1, L2}, default = L2) :

    the norm to use for difference computation

Description

This algorithm computes the spectral flux of a spectrum. Flux is defined as the L2-norm [1] or L1-norm [2] of the difference between two consecutive frames of the magnitude spectrum. The frames have to be of the same size in order to yield a meaningful result. The default L2-norm is used more commonly.

An exception is thrown if the size of the input spectrum does not equal the previous input spectrum’s size.

References:

[1] Tzanetakis, G., Cook, P., “Multifeature Audio Segmentation for Browsing and Annotation”, Proceedings of the 1999 IEEE Workshop on Applications of Signal Processing to Audio and Acoustics, New Paltz, NY, USA, 1999, W99 1-4

[2] S. Dixon, “Onset detection revisited”, in International Conference on Digital Audio Effects (DAFx’06), 2006, vol. 120, pp. 133-137.

[3] http://en.wikipedia.org/wiki/Spectral_flux

Source code

See also

Flux (streaming)