1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
|
/*************************************************************************/
/* audio_effect_distortion.cpp */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* https://godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2020 Juan Linietsky, Ariel Manzur. */
/* Copyright (c) 2014-2020 Godot Engine contributors (cf. AUTHORS.md). */
/* */
/* Permission is hereby granted, free of charge, to any person obtaining */
/* a copy of this software and associated documentation files (the */
/* "Software"), to deal in the Software without restriction, including */
/* without limitation the rights to use, copy, modify, merge, publish, */
/* distribute, sublicense, and/or sell copies of the Software, and to */
/* permit persons to whom the Software is furnished to do so, subject to */
/* the following conditions: */
/* */
/* The above copyright notice and this permission notice shall be */
/* included in all copies or substantial portions of the Software. */
/* */
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */
/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY */
/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, */
/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE */
/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
/*************************************************************************/
#include "audio_effect_distortion.h"
#include "core/math/math_funcs.h"
#include "servers/audio_server.h"
void AudioEffectDistortionInstance::process(const AudioFrame *p_src_frames, AudioFrame *p_dst_frames, int p_frame_count) {
const float *src = (const float *)p_src_frames;
float *dst = (float *)p_dst_frames;
//float lpf_c=expf(-2.0*Math_PI*keep_hf_hz.get()/(mix_rate*(float)OVERSAMPLE));
float lpf_c = expf(-2.0 * Math_PI * base->keep_hf_hz / (AudioServer::get_singleton()->get_mix_rate()));
float lpf_ic = 1.0 - lpf_c;
float drive_f = base->drive;
float pregain_f = Math::db2linear(base->pre_gain);
float postgain_f = Math::db2linear(base->post_gain);
float atan_mult = pow(10, drive_f * drive_f * 3.0) - 1.0 + 0.001;
float atan_div = 1.0 / (atanf(atan_mult) * (1.0 + drive_f * 8));
float lofi_mult = powf(2.0, 2.0 + (1.0 - drive_f) * 14); //goes from 16 to 2 bits
for (int i = 0; i < p_frame_count * 2; i++) {
float out = undenormalise(src[i] * lpf_ic + lpf_c * h[i & 1]);
h[i & 1] = out;
float a = out;
float ha = src[i] - out; //high freqs
a *= pregain_f;
switch (base->mode) {
case AudioEffectDistortion::MODE_CLIP: {
a = powf(a, 1.0001 - drive_f);
if (a > 1.0)
a = 1.0;
else if (a < (-1.0))
a = -1.0;
} break;
case AudioEffectDistortion::MODE_ATAN: {
a = atanf(a * atan_mult) * atan_div;
} break;
case AudioEffectDistortion::MODE_LOFI: {
a = floorf(a * lofi_mult + 0.5) / lofi_mult;
} break;
case AudioEffectDistortion::MODE_OVERDRIVE: {
const double x = a * 0.686306;
const double z = 1 + exp(sqrt(fabs(x)) * -0.75);
a = (expf(x) - expf(-x * z)) / (expf(x) + expf(-x));
} break;
case AudioEffectDistortion::MODE_WAVESHAPE: {
float x = a;
float k = 2 * drive_f / (1.00001 - drive_f);
a = (1.0 + k) * x / (1.0 + k * fabsf(x));
} break;
}
dst[i] = a * postgain_f + ha;
}
}
Ref<AudioEffectInstance> AudioEffectDistortion::instance() {
Ref<AudioEffectDistortionInstance> ins;
ins.instance();
ins->base = Ref<AudioEffectDistortion>(this);
ins->h[0] = 0;
ins->h[1] = 0;
return ins;
}
void AudioEffectDistortion::set_mode(Mode p_mode) {
mode = p_mode;
}
AudioEffectDistortion::Mode AudioEffectDistortion::get_mode() const {
return mode;
}
void AudioEffectDistortion::set_pre_gain(float p_pre_gain) {
pre_gain = p_pre_gain;
}
float AudioEffectDistortion::get_pre_gain() const {
return pre_gain;
}
void AudioEffectDistortion::set_keep_hf_hz(float p_keep_hf_hz) {
keep_hf_hz = p_keep_hf_hz;
}
float AudioEffectDistortion::get_keep_hf_hz() const {
return keep_hf_hz;
}
void AudioEffectDistortion::set_drive(float p_drive) {
drive = p_drive;
}
float AudioEffectDistortion::get_drive() const {
return drive;
}
void AudioEffectDistortion::set_post_gain(float p_post_gain) {
post_gain = p_post_gain;
}
float AudioEffectDistortion::get_post_gain() const {
return post_gain;
}
void AudioEffectDistortion::_bind_methods() {
ClassDB::bind_method(D_METHOD("set_mode", "mode"), &AudioEffectDistortion::set_mode);
ClassDB::bind_method(D_METHOD("get_mode"), &AudioEffectDistortion::get_mode);
ClassDB::bind_method(D_METHOD("set_pre_gain", "pre_gain"), &AudioEffectDistortion::set_pre_gain);
ClassDB::bind_method(D_METHOD("get_pre_gain"), &AudioEffectDistortion::get_pre_gain);
ClassDB::bind_method(D_METHOD("set_keep_hf_hz", "keep_hf_hz"), &AudioEffectDistortion::set_keep_hf_hz);
ClassDB::bind_method(D_METHOD("get_keep_hf_hz"), &AudioEffectDistortion::get_keep_hf_hz);
ClassDB::bind_method(D_METHOD("set_drive", "drive"), &AudioEffectDistortion::set_drive);
ClassDB::bind_method(D_METHOD("get_drive"), &AudioEffectDistortion::get_drive);
ClassDB::bind_method(D_METHOD("set_post_gain", "post_gain"), &AudioEffectDistortion::set_post_gain);
ClassDB::bind_method(D_METHOD("get_post_gain"), &AudioEffectDistortion::get_post_gain);
ADD_PROPERTY(PropertyInfo(Variant::INT, "mode", PROPERTY_HINT_ENUM, "Clip,ATan,LoFi,Overdrive,WaveShape"), "set_mode", "get_mode");
ADD_PROPERTY(PropertyInfo(Variant::REAL, "pre_gain", PROPERTY_HINT_RANGE, "-60,60,0.01"), "set_pre_gain", "get_pre_gain");
ADD_PROPERTY(PropertyInfo(Variant::REAL, "keep_hf_hz", PROPERTY_HINT_RANGE, "1,20500,1"), "set_keep_hf_hz", "get_keep_hf_hz");
ADD_PROPERTY(PropertyInfo(Variant::REAL, "drive", PROPERTY_HINT_RANGE, "0,1,0.01"), "set_drive", "get_drive");
ADD_PROPERTY(PropertyInfo(Variant::REAL, "post_gain", PROPERTY_HINT_RANGE, "-80,24,0.01"), "set_post_gain", "get_post_gain");
BIND_ENUM_CONSTANT(MODE_CLIP);
BIND_ENUM_CONSTANT(MODE_ATAN);
BIND_ENUM_CONSTANT(MODE_LOFI);
BIND_ENUM_CONSTANT(MODE_OVERDRIVE);
BIND_ENUM_CONSTANT(MODE_WAVESHAPE);
}
AudioEffectDistortion::AudioEffectDistortion() {
mode = MODE_CLIP;
pre_gain = 0;
post_gain = 0;
keep_hf_hz = 16000;
drive = 0;
}
|