sampling rate of x (only needed if x is a
numeric vector)
windowLength_points
length of fft window (points)
wn
window type accepted by ftwindow, currently
gaussian, hanning, hamming, bartlett, rectangular, blackman, flattop
step
you can override overlap by specifying FFT step, ms (NB:
because digital audio is sampled at discrete time intervals of
1/samplingRate, the actual step and thus the time stamps of STFT frames
may be slightly different, eg 24.98866 instead of 25.0 ms)
zp
window length after zero padding, points
normalize
if TRUE, scales input prior to FFT
filter
fft window filter (defaults to NULL)
padWithSilence
if TRUE, pads the sound with just enough silence to
resolve the edges properly (only the original region is plotted, so the
apparent duration doesn't change)
timeShift
time (s) added to timestamps
Value
A matrix with nrow = windowLength_points/2 and ncol
depending on length(sound) and step
Details
A subroutine of spec that saves windowed (and optionally
zero-padded) frames, i.e. chunks of the sound file of the right size and
spacing. Handy for further processing.