mirror of https://github.com/TeamNewPipe/NewPipe
38 lines
1.2 KiB
Java
38 lines
1.2 KiB
Java
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package org.schabi.newpipe.player.helper;
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/**
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* Converts between percent and 12-tone equal temperament semitones.
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* <br/>
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* @see
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* <a href="https://en.wikipedia.org/wiki/Equal_temperament#Twelve-tone_equal_temperament">
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* Wikipedia: Equal temperament#Twelve-tone equal temperament
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* </a>
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*/
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public final class PlayerSemitoneHelper {
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public static final int TONES = 12;
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private PlayerSemitoneHelper() {
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// No impl
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}
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public static String formatPitchSemitones(final double percent) {
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return formatPitchSemitones(percentToSemitones(percent));
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}
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public static String formatPitchSemitones(final int semitones) {
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return semitones > 0 ? "+" + semitones : "" + semitones;
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}
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public static double semitonesToPercent(final int semitones) {
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return Math.pow(2, ensureSemitonesInRange(semitones) / (double) TONES);
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}
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public static int percentToSemitones(final double percent) {
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return ensureSemitonesInRange((int) Math.round(TONES * Math.log(percent) / Math.log(2)));
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}
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private static int ensureSemitonesInRange(final int semitones) {
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return Math.max(-TONES, Math.min(TONES, semitones));
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}
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}
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