streaming mode | Standard category


  • array (vector_real) - the array to be analyzed


  • warpedAutoCorrelation (vector_real) - the warped auto-correlation vector


  • maxLag (integer ∈ (0, ∞), default = 1) :

    the maximum lag for which the auto-correlation is computed (inclusive) (must be smaller than signal size)

  • sampleRate (real ∈ (0, ∞), default = 44100) :

    the audio sampling rate [Hz]


This algorithm computes the warped auto-correlation of an audio signal. The implementation is an adapted version of K. Schmidt’s implementation of the matlab algorithm from the ‘warped toolbox’ by Aki Harma and Matti Karjalainen found [2]. For a detailed explanation of the algorithm, see [1]. This algorithm is only defined for positive lambda = 1.0674*sqrt(2.0*atan(0.00006583*sampleRate)/PI) - 0.1916, thus it will throw an exception when the supplied sampling rate does not pass the requirements. If maxLag is larger than the size of the input array, an exception is thrown.


[1] A. Härmä, M. Karjalainen, L. Savioja, V. Välimäki, U. K. Laine, and J. Huopaniemi, “Frequency-Warped Signal Processing for Audio Applications,” JAES, vol. 48, no. 11, pp. 1011–1031, 2000.

[2] WarpTB - Matlab Toolbox for Warped DSP http://www.acoustics.hut.fi/software/warp

Source code

See also

WarpedAutoCorrelation (standard)