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/*************************************************************************/
/* audio_effect_limiter.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_limiter.h"
void AudioEffectLimiterInstance::process(const AudioFrame *p_src_frames, AudioFrame *p_dst_frames, int p_frame_count) {
float threshdb = base->threshold;
float ceiling = Math::db2linear(base->ceiling);
float ceildb = base->ceiling;
float makeup = Math::db2linear(ceildb - threshdb);
float sc = -base->soft_clip;
float scv = Math::db2linear(sc);
float peakdb = ceildb + 25;
float scmult = Math::abs((ceildb - sc) / (peakdb - sc));
for (int i = 0; i < p_frame_count; i++) {
float spl0 = p_src_frames[i].l;
float spl1 = p_src_frames[i].r;
spl0 = spl0 * makeup;
spl1 = spl1 * makeup;
float sign0 = (spl0 < 0.0 ? -1.0 : 1.0);
float sign1 = (spl1 < 0.0 ? -1.0 : 1.0);
float abs0 = Math::abs(spl0);
float abs1 = Math::abs(spl1);
float overdb0 = Math::linear2db(abs0) - ceildb;
float overdb1 = Math::linear2db(abs1) - ceildb;
if (abs0 > scv) {
spl0 = sign0 * (scv + Math::db2linear(overdb0 * scmult));
}
if (abs1 > scv) {
spl1 = sign1 * (scv + Math::db2linear(overdb1 * scmult));
}
spl0 = MIN(ceiling, Math::abs(spl0)) * (spl0 < 0.0 ? -1.0 : 1.0);
spl1 = MIN(ceiling, Math::abs(spl1)) * (spl1 < 0.0 ? -1.0 : 1.0);
p_dst_frames[i].l = spl0;
p_dst_frames[i].r = spl1;
}
}
Ref<AudioEffectInstance> AudioEffectLimiter::instance() {
Ref<AudioEffectLimiterInstance> ins;
ins.instance();
ins->base = Ref<AudioEffectLimiter>(this);
return ins;
}
void AudioEffectLimiter::set_threshold_db(float p_threshold) {
threshold = p_threshold;
}
float AudioEffectLimiter::get_threshold_db() const {
return threshold;
}
void AudioEffectLimiter::set_ceiling_db(float p_ceiling) {
ceiling = p_ceiling;
}
float AudioEffectLimiter::get_ceiling_db() const {
return ceiling;
}
void AudioEffectLimiter::set_soft_clip_db(float p_soft_clip) {
soft_clip = p_soft_clip;
}
float AudioEffectLimiter::get_soft_clip_db() const {
return soft_clip;
}
void AudioEffectLimiter::set_soft_clip_ratio(float p_soft_clip) {
soft_clip_ratio = p_soft_clip;
}
float AudioEffectLimiter::get_soft_clip_ratio() const {
return soft_clip_ratio;
}
void AudioEffectLimiter::_bind_methods() {
ClassDB::bind_method(D_METHOD("set_ceiling_db", "ceiling"), &AudioEffectLimiter::set_ceiling_db);
ClassDB::bind_method(D_METHOD("get_ceiling_db"), &AudioEffectLimiter::get_ceiling_db);
ClassDB::bind_method(D_METHOD("set_threshold_db", "threshold"), &AudioEffectLimiter::set_threshold_db);
ClassDB::bind_method(D_METHOD("get_threshold_db"), &AudioEffectLimiter::get_threshold_db);
ClassDB::bind_method(D_METHOD("set_soft_clip_db", "soft_clip"), &AudioEffectLimiter::set_soft_clip_db);
ClassDB::bind_method(D_METHOD("get_soft_clip_db"), &AudioEffectLimiter::get_soft_clip_db);
ClassDB::bind_method(D_METHOD("set_soft_clip_ratio", "soft_clip"), &AudioEffectLimiter::set_soft_clip_ratio);
ClassDB::bind_method(D_METHOD("get_soft_clip_ratio"), &AudioEffectLimiter::get_soft_clip_ratio);
ADD_PROPERTY(PropertyInfo(Variant::REAL, "ceiling_db", PROPERTY_HINT_RANGE, "-20,-0.1,0.1"), "set_ceiling_db", "get_ceiling_db");
ADD_PROPERTY(PropertyInfo(Variant::REAL, "threshold_db", PROPERTY_HINT_RANGE, "-30,0,0.1"), "set_threshold_db", "get_threshold_db");
ADD_PROPERTY(PropertyInfo(Variant::REAL, "soft_clip_db", PROPERTY_HINT_RANGE, "0,6,0.1"), "set_soft_clip_db", "get_soft_clip_db");
ADD_PROPERTY(PropertyInfo(Variant::REAL, "soft_clip_ratio", PROPERTY_HINT_RANGE, "3,20,0.1"), "set_soft_clip_ratio", "get_soft_clip_ratio");
}
AudioEffectLimiter::AudioEffectLimiter() {
threshold = 0;
ceiling = -0.1;
soft_clip = 2;
soft_clip_ratio = 10;
}
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