sndfft


NAME

sndfft − Applies a Fast Fourier Transform to a soundfile

SYNOPSIS

sndfft soundfile

DESCRIPTION

sndfft applies an FFT to the soundfile, and puts its output into a textfile with x/y pairs in columns, "x" representing the frequency and "y" representing the amplitude in decibels.

The output is written to a file named "fft.data". This is useful for reading into programs such as "gnuplot", or "octave" for graphic analysis.

FFT algorithm written by Dale Carestensen.

USAGE

sndfft [−l fftlen][−w winType][−x xmax] soundfile

OPTIONS

−l

Length of fft (must be power of 2). Default: 1024

−w

Window type:

0=noWindow, 1=Hamming, 2=Hanning, 3=Hartlett,4=Blackman,

5=Blackman-Harris. Default: Hamming

−x

Highest frequency (xvalue) displayed. Default: Nyquist frequency

(SamplingRate/2)

BUGS

This program will only work with WAVE, AIFF, AIFC, and the old NeXT/Sun "snd" format soundfiles, that are 16-bit PCM encoded, with 1 or 2 channels.

AUTHOR

Arun Chandra <arunc@evergreen.edu>

sndfft is free software.