1#!/usr/bin/python 2 3# ---------------------------------------------------------------------------- 4# 5# Copyright (C) 2008-2020 Fons Adriaensen <fons@linuxaudio.org> 6# 7# This program is free software; you can redistribute it and/or modify 8# it under the terms of the GNU General Public License as published by 9# the Free Software Foundation; either version 3 of the License, or 10# (at your option) any later version. 11# 12# This program is distributed in the hope that it will be useful, 13# but WITHOUT ANY WARRANTY; without even the implied warranty of 14# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15# GNU General Public License for more details. 16# 17# You should have received a copy of the GNU General Public License 18# along with this program. If not, see <http:#www.gnu.org/licenses/>. 19# 20# ---------------------------------------------------------------------------- 21 22import sys 23import numpy as np 24import matplotlib.pyplot as plt 25from scipy.signal import convolve # much faster than numpy.convolve 26from jacktools.jacksignal import JackSignal 27sys.path.append ('..') 28from utils.logsweep import genlogsweep 29 30 31# ------- Frequency response using log sweep, deconvolution and fft --------- 32# 33# Make sure jnoisemeter is running, using 34# input 1, and select the A, C or ITU filter. 35 36 37# Create a JackSignal object and connect. 38# 39J = JackSignal("JackSignal") 40if J.get_state() < 0: 41 print ("Failed to create JackSignal -- is Jack running ?") 42 exit(1) 43J.create_output (0, "out") 44J.create_input (0, "in") 45J.silence() 46J.connect_output (0, "jnoisemeter:in_1") 47J.connect_input (0, "jnoisemeter:out") 48 49# Get Jack info. 50# 51name, fsamp, period = J.get_jack_info () 52 53# Sweep parameters. 54# 55amp = 0.1 56fmin = 20 57fmax = 22.0e3 58tfade1 = 0.50 59tsweep = 5.00 60tfade2 = 0.01 61implen = 15000 62 63# Generate sweep. 64# 65Afwd, Ainv, p = genlogsweep (amp, fmin, fmax, fsamp, tfade1, tsweep, tfade2) 66 67# Create input buffer. 68# 69k = implen + Afwd.shape [0] - 1 70Ainp = np.zeros ([k,], dtype = np.float32) 71 72# Connect buffer to ports. 73# 74J.set_output_data (0, Afwd) 75J.set_input_data (0, Ainp, nskip = period) 76 77# Run the test 78# 79print ("Measuring....") 80J.process() 81J.wait() 82del J 83 84# Process and store result 85# 86print ("Convolving....") 87Imp = convolve (Ainp, Ainv, mode = 'valid') 88Lfft = 0x4000 89Nbin = Lfft // 2 + 1 90Spec = np.fft.rfft (Imp, Lfft) 91 92# Display impulse and magnitude response. 93# 94print ("Display...") 95Freq = np.linspace (0, fsamp / 2, Nbin) 96 97fig = plt.figure (figsize=(8,6), facecolor='white') 98k = Afwd.shape [0] 99ax1 = fig.add_axes ([0.07, 0.04, 0.90, 0.44]) 100ax1.set_ylim (-1.5, 1.5) 101ax1.plot (Imp [0:100], color='b', lw=1) 102ax1.grid () 103 104ax2 = fig.add_axes ([0.07, 0.53, 0.90, 0.44]) 105ax2.set_xlim (20, 20e3) 106ax2.set_ylim (-60, 15) 107ax2.set_xscale ('log') 108ax2.plot (Freq, 20 * np.log10 (np.abs (Spec) + 1e-10), color='b', lw=1) 109ax2.grid () 110plt.show() 111