| # Copyright © 2020 Sébastien Piquemal [email protected] | |
| # This work is free. You can redistribute it and/or modify it under the | |
| # terms of the Do What The Fuck You Want To Public License, Version 2, | |
| # as published by Sam Hocevar. See the license text below for more details. | |
| # | |
| # -------------------------------------------------------------------- | |
| # | |
| # DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE | |
| # Version 2, December 2004 | |
| # |
| function x = istft(d, ftsize, w, h) | |
| % X = istft(D, F, W, H) Inverse short-time Fourier transform. | |
| % Performs overlap-add resynthesis from the short-time Fourier transform | |
| % data in D. Each column of D is taken as the result of an F-point | |
| % fft; each successive frame was offset by H points (default | |
| % W/2, or F/2 if W==0). Data is hann-windowed at W pts, or | |
| % W = 0 gives a rectangular window (default); | |
| % W as a vector uses that as window. | |
| % This version scales the output so the loop gain is 1.0 for | |
| % either hann-win an-syn with 25% overlap, or hann-win on |
Empirically testing whether FWT or FFT is faster. Disclaimer: I don't understand wavelets.
Speed of FFT implementation doesn't care what the data is:
In [23]: a = rand(2**20)
In [24]: timeit fft(a)
10 loops, best of 3: 128 ms per loop
In [25]: a = rand(2**20)
| # | |
| # Based on multiprocessing.sharedctypes.RawArray | |
| # | |
| # Uses posix_ipc (http://semanchuk.com/philip/posix_ipc/) to allow shared ctypes arrays | |
| # among unrelated processors | |
| # | |
| # Usage Notes: | |
| # * The first two args (typecode_or_type and size_or_initializer) should work the same as with RawArray. | |
| # * The shared array is accessible by any process, as long as tag matches. | |
| # * The shared memory segment is unlinked when the origin array (that returned |
| from __future__ import division | |
| from numpy.fft import rfft | |
| from numpy import argmax, mean, diff, log, nonzero | |
| from scipy.signal import blackmanharris, correlate | |
| from time import time | |
| import sys | |
| try: | |
| import soundfile as sf | |
| except ImportError: | |
| from scikits.audiolab import flacread |
| from numpy import linspace, cos, pi, absolute | |
| from numpy.fft import fft, fftfreq, fftshift | |
| import matplotlib.pyplot as plt | |
| # Sampling rate | |
| fs = 64 # Hz | |
| # Time is from 0 to 1 seconds, but leave off the endpoint, so | |
| # that 1.0 seconds is the first sample of the *next* chunk | |
| length = 1 # second |