Mpeg7 audio feature

在頻率上級時間上共有17種描述，分成六個群組：
Timbral Temporal，Timbral Spectral，Basic Spectral，Basic，
Signal Parameters，Spectral Basic。
 下面採用前三種。

two timbral temporal feature：
Log Attack Time (LAT)
Temporal Centroid (TC)

four basic spectral time-freqency amalysis：
Audio Spectral Envelope (ASE)
Audio Spectral Centroid (ASC)
Audio Spectral Spread (ASS)
Audio Spectral Flatness (ASF)

five timbral spectral feature：
Spectral Centroid (SC)
Harmonic Spectral Centroid (HSC)
Harmonic Spectral Deviation (HSD)
Harmonic Spectral Spread (HSS)
Harmonic Spectral Variation (HSV)

other
Linear Predictive Coding (LPC)
Mel-scale Freqency Ceptral Coefficient (MFCC)
Zero-Crossing Rate (ZCR)
Pitch
Sound Pressure Level (SPL)
Autocorrelation
Skewness
Kurtosis