R: Mel-filter bank for MFCC computation

melfilterbank {seewave}

R Documentation

Mel-filter bank for MFCC computation

Description

This functions returns graphically and numerically the Mel-filters used to compute MFCC.

Usage

melfilterbank(f = 44100, wl = 1024,
minfreq = 0, maxfreq = f/2, m = 20,
palette, alpha = 0.5, plot = FALSE)

Arguments

`f`	sammpling frequency (in Hz).
`wl`	the Fourier window length (in number of samples).
`minfreq`	the minimum (or lower) frequency of the filter bank (in Hz).
`maxfreq`	the maximum (or upper) frequency of the filter bank (in Hz).
`m`	the total number of filters.
`palette`	an optional colour palette if `plot` is `TRUE`.
`alpha`	alpha-transparency when a colour palette is used.
`plot`	if `TRUE` all filters are displayed in a single plot.

Value

A list of 3 items:

`central.freq`	the kHz central frequencies of the filters,
`freq`	the kHz frequency scale,
`amp`	the amplitude of the filters, scaled between 0 and 1.

Note

These triangular filters are used for computing MFCCs.

Author(s)

Jerome Sueur

References

Sharan RV & Moir TJ (2016) Applications and advancements in automatic sound recognition. Neurocomputing.

Examples

## default values
melfilterbank(plot=TRUE)
## with color surfaces
melfilterbank(palette=cm.colors, plot=TRUE)
## values changed
res <- melfilterbank(f=16000, wl=512, minfreq=300, plot=TRUE)
## plot the 1st filter only
plot(res$freq, res$amp[,1], type="l", xlab="Frequency (kHz)", ylab="Amplitude")
## plot the last filter only
plot(res$freq, res$amp[,ncol(res$amp)], type="l", xlab="Frequency (kHz)", ylab="Amplitude")
## get the kHz central frequencies of the succesive filters
res$central.freq

[Package seewave version 2.1.6 Index]