Time

Energy(g)

\(O\left( N \right)\)

Zerocrossing rate (ZCR)

Loudness (L)

Frequency

Spectral flux (SX)

STFT which costs \(O\left( {N\log_{2} N} \right)\)

Spectral rolloff (SR)

Spectral flatness (SF)

Wavelet

The mean of the subband’s coefficients (M)

1D Haar which costs \(O\left( N \right)\)

The standard deviation of the subband’s coefficients (STD)

The ratio of absolute mean values of two adjacent subbands (RM)

The energy variance of the subband’s coefficients (E)

The energy ratio between two adjacent subbands (ER)

The temporal centroid per subband (TC)

The difference between the temporal centroids of two adjacent subbands (TCD)

The entropy per subband (P)
