102 lines
2.3 KiB
C++
102 lines
2.3 KiB
C++
/*
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* Olive Community Edition - Non-Linear Video Editor
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* Copyright (C) 2025 Olive CE Team
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*
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* This program is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#ifndef DECIBEL_H
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#define DECIBEL_H
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#include <QtGlobal>
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#include <cmath>
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//#define ALLOW_RETURNING_INFINITY
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namespace olive
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{
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class Decibel {
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public:
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// In basically all circumstances, this should calculate to 0.0 linear
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static constexpr double MINIMUM = -200.0;
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static double fromLinear(double linear)
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{
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double v = double(20.0) * std::log10(linear);
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#ifndef ALLOW_RETURNING_INFINITY
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if (std::isinf(v)) {
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return MINIMUM;
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}
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#endif
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return v;
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}
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static double toLinear(double decibel)
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{
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double to_linear = std::pow(double(10.0), decibel / double(20.0));
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// Minimum threshold that we figure is close enough to 0 that we may as well just return 0
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if (to_linear < 0.000001) {
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return 0;
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} else {
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return to_linear;
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}
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}
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static double fromLogarithmic(double logarithmic)
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{
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if (logarithmic < 0.001)
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#ifdef ALLOW_RETURNING_INFINITY
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return std::numeric_limits<double>::infinity();
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#else
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return MINIMUM;
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#endif
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else if (logarithmic > 0.99)
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return 0;
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else
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return 20.0 * std::log10(-std::log(1 - logarithmic) / LOG100);
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}
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static double toLogarithmic(double decibel)
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{
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if (qFuzzyIsNull(decibel)) {
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return 1;
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} else {
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return 1 - std::exp(-std::pow(10.0, decibel / 20.0) * LOG100);
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}
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}
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static double LinearToLogarithmic(double linear)
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{
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return 1 - std::exp(-linear * LOG100);
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}
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static double LogarithmicToLinear(double logarithmic)
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{
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if (logarithmic > 0.99) {
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return 1;
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} else {
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return -std::log(1 - logarithmic) / LOG100;
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}
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}
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private:
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static constexpr double LOG100 = 4.60517018599;
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};
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}
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#endif // DECIBEL_H
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