1#!/usr/bin/python2.5 2# 3# Copyright 2017 Emilie Gillet. 4# 5# Author: Emilie Gillet (emilie.o.gillet@gmail.com) 6# 7# Permission is hereby granted, free of charge, to any person obtaining a copy 8# of this software and associated documentation files (the "Software"), to deal 9# in the Software without restriction, including without limitation the rights 10# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 11# copies of the Software, and to permit persons to whom the Software is 12# furnished to do so, subject to the following conditions: 13# 14# The above copyright notice and this permission notice shall be included in 15# all copies or substantial portions of the Software. 16# 17# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 18# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 19# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 20# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 21# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 22# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 23# THE SOFTWARE. 24# 25# See http://creativecommons.org/licenses/MIT/ for more information. 26# 27# ----------------------------------------------------------------------------- 28# 29# Lookup table definitions. 30 31import numpy 32import pylab 33 34lookup_tables = [] 35lookup_tables_i16 = [] 36 37sample_rate = 48000 38 39"""---------------------------------------------------------------------------- 40Sine table. 41----------------------------------------------------------------------------""" 42 43size = 1024 44t = numpy.arange(0, size + size / 4 + 1) / float(size) * numpy.pi * 2 45lookup_tables.append(('sine', numpy.sin(t))) 46 47 48 49"""---------------------------------------------------------------------------- 50Waveshaper for audio rate 51----------------------------------------------------------------------------""" 52 53WAVESHAPER_SIZE = 1024 54 55x = numpy.arange(0, WAVESHAPER_SIZE) / float(WAVESHAPER_SIZE) 56 57linear = x 58sin = 0.5 - 0.5 * numpy.cos(x * numpy.pi) 59tan = numpy.arctan(8 * numpy.cos(numpy.pi * x)) 60tan_scale = tan.max() 61fade_crop = numpy.minimum(1.0, 4.0 - 4.0 * x) 62bump = (1.0 - numpy.cos(numpy.pi * x * 1.5)) * (1.0 - numpy.cos(numpy.pi * fade_crop)) / 4.5 63inverse_sin = numpy.arccos(1 - 2 * x) / numpy.pi 64inverse_tan = numpy.arccos(numpy.tan(tan_scale * (1.0 - 2.0 * x)) / 8.0) / numpy.pi 65inverse_tan[0] = 0 66 67def scale(x): 68 x = numpy.array(list(x) + [x[-1]]) 69 # pylab.plot(x) 70 # pylab.show() 71 return list(numpy.round((x * 32767.0)).astype(int)) 72 73wavetable = [] 74wavetable += scale(inverse_tan) 75wavetable += scale(inverse_sin) 76wavetable += scale(linear) 77wavetable += scale(sin) 78wavetable += scale(bump) 79 80"""---------------------------------------------------------------------------- 81Waveshaper for control rate 82----------------------------------------------------------------------------""" 83 84x = numpy.arange(0, WAVESHAPER_SIZE / 2) / float(WAVESHAPER_SIZE / 2) 85linear = x 86sin = (1.0 - numpy.cos(numpy.pi * x)) / 2.0 87inverse_sin = numpy.arccos(1 - 2 * x) / numpy.pi 88expo = 1.0 - numpy.exp(-5 * x) 89expo_max = expo.max() 90expo /= expo_max 91log = numpy.log(1.0 - x * expo_max) / -5.0 92 93def scale_flip(x, flip=True): 94 if flip: 95 y = x[::-1] 96 else: 97 y = 1.0 - x 98 x = numpy.array(list(x) + [1] + list(y)) 99 return list(numpy.round((x * 32767.0)).astype(int)) 100 101wavetable += scale_flip(log, False) 102wavetable += scale_flip(log, True) 103wavetable += scale_flip(inverse_sin, False) 104wavetable += scale_flip(linear, False) 105wavetable += scale_flip(sin, False) 106wavetable += scale_flip(expo, True) 107wavetable += scale_flip(expo, False) 108 109lookup_tables_i16.append(('wavetable', wavetable)) 110 111 112 113"""---------------------------------------------------------------------------- 114Post waveshaper 115----------------------------------------------------------------------------""" 116 117x = numpy.arange(0, WAVESHAPER_SIZE + 4) / (WAVESHAPER_SIZE / 2.0) - 1.0 118x[-1] = x[-2] 119sine = numpy.sin(8 * numpy.pi * x) 120window = numpy.exp(-x * x * 4) ** 2 121bipolar_fold = sine * window + numpy.arctan(3 * x) * (1 - window) 122bipolar_fold /= numpy.abs(bipolar_fold).max() 123lookup_tables.append(('bipolar_fold', bipolar_fold)) 124 125x = numpy.arange(0, WAVESHAPER_SIZE + 4) / float(WAVESHAPER_SIZE) 126x[-1] = x[-3] 127x[-2] = x[-3] 128sine = numpy.sin(16 * numpy.pi * x) 129window = numpy.exp(-x * x * 4) ** 2 130unipolar_fold = (0.38 * sine + 4 * x) * window + numpy.arctan(4 * x) * (1 - window) 131unipolar_fold /= numpy.abs(unipolar_fold).max() 132lookup_tables.append(('unipolar_fold', unipolar_fold)) 133