ref: 2a14820a54dc6147abcd3c8eabd2eb0eaa5e9755
dir: /python/demos/demo_filterbank.py/
#! /usr/bin/env python from aubio import filterbank, fvec from pylab import loglog, show, subplot, xlim, ylim, xlabel, ylabel, title from numpy import vstack, arange win_s = 2048 samplerate = 48000 freq_list = [60, 80, 200, 400, 800, 1600, 3200, 6400, 12800, 24000] n_filters = len(freq_list) - 2 f = filterbank(n_filters, win_s) freqs = fvec(freq_list) f.set_triangle_bands(freqs, samplerate) coeffs = f.get_coeffs() coeffs[4] *= 5. f.set_coeffs(coeffs) times = vstack([arange(win_s / 2 + 1) * samplerate / win_s] * n_filters) title('Bank of filters built using a simple list of boundaries\nThe middle band has been amplified by 2.') loglog(times.T, f.get_coeffs().T, '.-') xlim([50, samplerate/2]) ylim([1.0e-6, 2.0e-2]) xlabel('log frequency (Hz)') ylabel('log amplitude') show()