Mercurial > hg > svcore
view base/Pitch.cpp @ 377:166c22eff678
* Ensure waveforms are strictly correct even when using a non-power-of-two
non-power-of-sqrt-two block size with cacheing off and painting only small
areas at a time
author | Chris Cannam |
---|---|
date | Thu, 07 Feb 2008 15:25:05 +0000 |
parents | 0a44caddd9fe |
children | ad4911230a66 |
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/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*- vi:set ts=8 sts=4 sw=4: */ /* Sonic Visualiser An audio file viewer and annotation editor. Centre for Digital Music, Queen Mary, University of London. This file copyright 2006 Chris Cannam. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. See the file COPYING included with this distribution for more information. */ #include "Pitch.h" #include "Preferences.h" #include <cmath> float Pitch::getFrequencyForPitch(int midiPitch, float centsOffset, float concertA) { if (concertA <= 0.0) { concertA = Preferences::getInstance()->getTuningFrequency(); } float p = float(midiPitch) + (centsOffset / 100); return concertA * powf(2.0, (p - 69.0) / 12.0); } int Pitch::getPitchForFrequency(float frequency, float *centsOffsetReturn, float concertA) { if (concertA <= 0.0) { concertA = Preferences::getInstance()->getTuningFrequency(); } float p = 12.0 * (log(frequency / (concertA / 2.0)) / log(2.0)) + 57.0; int midiPitch = int(p + 0.00001); float centsOffset = (p - midiPitch) * 100.0; if (centsOffset >= 50.0) { midiPitch = midiPitch + 1; centsOffset = -(100.0 - centsOffset); } if (centsOffsetReturn) *centsOffsetReturn = centsOffset; return midiPitch; } int Pitch::getPitchForFrequencyDifference(float frequencyA, float frequencyB, float *centsOffsetReturn, float concertA) { if (concertA <= 0.0) { concertA = Preferences::getInstance()->getTuningFrequency(); } if (frequencyA > frequencyB) { std::swap(frequencyA, frequencyB); } float pA = 12.0 * (log(frequencyA / (concertA / 2.0)) / log(2.0)) + 57.0; float pB = 12.0 * (log(frequencyB / (concertA / 2.0)) / log(2.0)) + 57.0; float p = pB - pA; int midiPitch = int(p + 0.00001); float centsOffset = (p - midiPitch) * 100.0; if (centsOffset >= 50.0) { midiPitch = midiPitch + 1; centsOffset = -(100.0 - centsOffset); } if (centsOffsetReturn) *centsOffsetReturn = centsOffset; return midiPitch; } static QString notes[] = { "C%1", "C#%1", "D%1", "D#%1", "E%1", "F%1", "F#%1", "G%1", "G#%1", "A%1", "A#%1", "B%1" }; static QString flatNotes[] = { "C%1", "Db%1", "D%1", "Eb%1", "E%1", "F%1", "Gb%1", "G%1", "Ab%1", "A%1", "Bb%1", "B%1" }; QString Pitch::getPitchLabel(int midiPitch, float centsOffset, bool useFlats) { int octave = -2; if (midiPitch < 0) { while (midiPitch < 0) { midiPitch += 12; --octave; } } else { octave = midiPitch / 12 - 2; } QString plain = (useFlats ? flatNotes : notes)[midiPitch % 12].arg(octave); int ic = lrintf(centsOffset); if (ic == 0) return plain; else if (ic > 0) return QString("%1+%2c").arg(plain).arg(ic); else return QString("%1%2c").arg(plain).arg(ic); } QString Pitch::getPitchLabelForFrequency(float frequency, float concertA, bool useFlats) { if (concertA <= 0.0) { concertA = Preferences::getInstance()->getTuningFrequency(); } float centsOffset = 0.0; int midiPitch = getPitchForFrequency(frequency, ¢sOffset, concertA); return getPitchLabel(midiPitch, centsOffset, useFlats); } QString Pitch::getLabelForPitchRange(int semis, float cents) { int ic = lrintf(cents); if (ic == 0) { if (semis >= 12) { return QString("%1'%2").arg(semis/12).arg(semis - 12*(semis/12)); } else { return QString("%1").arg(semis); } } else { if (ic > 0) { if (semis >= 12) { return QString("%1'%2+%3c").arg(semis/12).arg(semis - 12*(semis/12)).arg(ic); } else { return QString("%1+%3c").arg(semis).arg(ic); } } else { if (semis >= 12) { return QString("%1'%2%3c").arg(semis/12).arg(semis - 12*(semis/12)).arg(ic); } else { return QString("%1%3c").arg(semis).arg(ic); } } } } bool Pitch::isFrequencyInMidiRange(float frequency, float concertA) { float centsOffset = 0.0; int midiPitch = getPitchForFrequency(frequency, ¢sOffset, concertA); return (midiPitch >= 0 && midiPitch < 128); }