1/**************************************************************************/
2/* audio_effect_compressor.cpp */
3/**************************************************************************/
4/* This file is part of: */
5/* GODOT ENGINE */
6/* https://godotengine.org */
7/**************************************************************************/
8/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
9/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur. */
10/* */
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12/* a copy of this software and associated documentation files (the */
13/* "Software"), to deal in the Software without restriction, including */
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15/* distribute, sublicense, and/or sell copies of the Software, and to */
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17/* the following conditions: */
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20/* included in all copies or substantial portions of the Software. */
21/* */
22/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */
23/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */
24/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. */
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28/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
29/**************************************************************************/
30
31#include "audio_effect_compressor.h"
32#include "servers/audio_server.h"
33
34void AudioEffectCompressorInstance::process(const AudioFrame *p_src_frames, AudioFrame *p_dst_frames, int p_frame_count) {
35 float threshold = Math::db_to_linear(base->threshold);
36 float sample_rate = AudioServer::get_singleton()->get_mix_rate();
37
38 float ratatcoef = exp(-1 / (0.00001f * sample_rate));
39 float ratrelcoef = exp(-1 / (0.5f * sample_rate));
40 float attime = base->attack_us / 1000000.0;
41 float reltime = base->release_ms / 1000.0;
42 float atcoef = exp(-1 / (attime * sample_rate));
43 float relcoef = exp(-1 / (reltime * sample_rate));
44
45 float makeup = Math::db_to_linear(base->gain);
46
47 float mix = base->mix;
48 float gr_meter_decay = exp(1 / (1 * sample_rate));
49
50 const AudioFrame *src = p_src_frames;
51
52 if (base->sidechain != StringName() && current_channel != -1) {
53 int bus = AudioServer::get_singleton()->thread_find_bus_index(base->sidechain);
54 if (bus >= 0) {
55 src = AudioServer::get_singleton()->thread_get_channel_mix_buffer(bus, current_channel);
56 }
57 }
58
59 for (int i = 0; i < p_frame_count; i++) {
60 AudioFrame s = src[i];
61 //convert to positive
62 s.l = Math::abs(s.l);
63 s.r = Math::abs(s.r);
64
65 float peak = MAX(s.l, s.r);
66
67 float overdb = 2.08136898f * Math::linear_to_db(peak / threshold);
68
69 if (overdb < 0.0) { //we only care about what goes over to compress
70 overdb = 0.0;
71 }
72
73 if (overdb - rundb > 5) { // diffeence is too large
74 averatio = 4;
75 }
76
77 if (overdb > rundb) {
78 rundb = overdb + atcoef * (rundb - overdb);
79 runratio = averatio + ratatcoef * (runratio - averatio);
80 } else {
81 rundb = overdb + relcoef * (rundb - overdb);
82 runratio = averatio + ratrelcoef * (runratio - averatio);
83 }
84
85 overdb = rundb;
86 averatio = runratio;
87
88 float cratio;
89
90 if (false) { //rato all-in
91 cratio = 12 + averatio;
92 } else {
93 cratio = base->ratio;
94 }
95
96 float gr = -overdb * (cratio - 1) / cratio;
97 float grv = Math::db_to_linear(gr);
98
99 runmax = maxover + relcoef * (runmax - maxover); // highest peak for setting att/rel decays in reltime
100 maxover = runmax;
101
102 if (grv < gr_meter) {
103 gr_meter = grv;
104 } else {
105 gr_meter *= gr_meter_decay;
106 if (gr_meter > 1) {
107 gr_meter = 1;
108 }
109 }
110
111 p_dst_frames[i] = p_src_frames[i] * grv * makeup * mix + p_src_frames[i] * (1.0 - mix);
112 }
113}
114
115Ref<AudioEffectInstance> AudioEffectCompressor::instantiate() {
116 Ref<AudioEffectCompressorInstance> ins;
117 ins.instantiate();
118 ins->base = Ref<AudioEffectCompressor>(this);
119 ins->rundb = 0;
120 ins->runratio = 0;
121 ins->averatio = 0;
122 ins->runmax = 0;
123 ins->maxover = 0;
124 ins->gr_meter = 1.0;
125 ins->current_channel = -1;
126 return ins;
127}
128
129void AudioEffectCompressor::set_threshold(float p_threshold) {
130 threshold = p_threshold;
131}
132
133float AudioEffectCompressor::get_threshold() const {
134 return threshold;
135}
136
137void AudioEffectCompressor::set_ratio(float p_ratio) {
138 ratio = p_ratio;
139}
140
141float AudioEffectCompressor::get_ratio() const {
142 return ratio;
143}
144
145void AudioEffectCompressor::set_gain(float p_gain) {
146 gain = p_gain;
147}
148
149float AudioEffectCompressor::get_gain() const {
150 return gain;
151}
152
153void AudioEffectCompressor::set_attack_us(float p_attack_us) {
154 attack_us = p_attack_us;
155}
156
157float AudioEffectCompressor::get_attack_us() const {
158 return attack_us;
159}
160
161void AudioEffectCompressor::set_release_ms(float p_release_ms) {
162 release_ms = p_release_ms;
163}
164
165float AudioEffectCompressor::get_release_ms() const {
166 return release_ms;
167}
168
169void AudioEffectCompressor::set_mix(float p_mix) {
170 mix = p_mix;
171}
172
173float AudioEffectCompressor::get_mix() const {
174 return mix;
175}
176
177void AudioEffectCompressor::set_sidechain(const StringName &p_sidechain) {
178 AudioServer::get_singleton()->lock();
179 sidechain = p_sidechain;
180 AudioServer::get_singleton()->unlock();
181}
182
183StringName AudioEffectCompressor::get_sidechain() const {
184 return sidechain;
185}
186
187void AudioEffectCompressor::_validate_property(PropertyInfo &p_property) const {
188 if (p_property.name == "sidechain") {
189 String buses = "";
190 for (int i = 0; i < AudioServer::get_singleton()->get_bus_count(); i++) {
191 buses += ",";
192 buses += AudioServer::get_singleton()->get_bus_name(i);
193 }
194
195 p_property.hint_string = buses;
196 }
197}
198
199void AudioEffectCompressor::_bind_methods() {
200 ClassDB::bind_method(D_METHOD("set_threshold", "threshold"), &AudioEffectCompressor::set_threshold);
201 ClassDB::bind_method(D_METHOD("get_threshold"), &AudioEffectCompressor::get_threshold);
202
203 ClassDB::bind_method(D_METHOD("set_ratio", "ratio"), &AudioEffectCompressor::set_ratio);
204 ClassDB::bind_method(D_METHOD("get_ratio"), &AudioEffectCompressor::get_ratio);
205
206 ClassDB::bind_method(D_METHOD("set_gain", "gain"), &AudioEffectCompressor::set_gain);
207 ClassDB::bind_method(D_METHOD("get_gain"), &AudioEffectCompressor::get_gain);
208
209 ClassDB::bind_method(D_METHOD("set_attack_us", "attack_us"), &AudioEffectCompressor::set_attack_us);
210 ClassDB::bind_method(D_METHOD("get_attack_us"), &AudioEffectCompressor::get_attack_us);
211
212 ClassDB::bind_method(D_METHOD("set_release_ms", "release_ms"), &AudioEffectCompressor::set_release_ms);
213 ClassDB::bind_method(D_METHOD("get_release_ms"), &AudioEffectCompressor::get_release_ms);
214
215 ClassDB::bind_method(D_METHOD("set_mix", "mix"), &AudioEffectCompressor::set_mix);
216 ClassDB::bind_method(D_METHOD("get_mix"), &AudioEffectCompressor::get_mix);
217
218 ClassDB::bind_method(D_METHOD("set_sidechain", "sidechain"), &AudioEffectCompressor::set_sidechain);
219 ClassDB::bind_method(D_METHOD("get_sidechain"), &AudioEffectCompressor::get_sidechain);
220
221 ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "threshold", PROPERTY_HINT_RANGE, "-60,0,0.1"), "set_threshold", "get_threshold");
222 ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "ratio", PROPERTY_HINT_RANGE, "1,48,0.1"), "set_ratio", "get_ratio");
223 ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "gain", PROPERTY_HINT_RANGE, "-20,20,0.1"), "set_gain", "get_gain");
224 ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "attack_us", PROPERTY_HINT_RANGE, U"20,2000,1,suffix:\u00B5s"), "set_attack_us", "get_attack_us");
225 ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "release_ms", PROPERTY_HINT_RANGE, "20,2000,1,suffix:ms"), "set_release_ms", "get_release_ms");
226 ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "mix", PROPERTY_HINT_RANGE, "0,1,0.01"), "set_mix", "get_mix");
227 ADD_PROPERTY(PropertyInfo(Variant::STRING_NAME, "sidechain", PROPERTY_HINT_ENUM), "set_sidechain", "get_sidechain");
228}
229
230AudioEffectCompressor::AudioEffectCompressor() {
231 threshold = 0;
232 ratio = 4;
233 gain = 0;
234 attack_us = 20;
235 release_ms = 250;
236 mix = 1;
237}
238