Mercurial > hg > svcore
view base/Pitch.cpp @ 77:2beca8ddcdc3
* Add BZipFileDevice to handle bzip2 compress/uncompress without all that
ugly code in MainWindow.cpp
* Remove all that ugly code in MainWindow.cpp and replace with uses of
BZipFileDevice
* Fix layer import/export for SV XML layers
* and a few other minor fixes
author | Chris Cannam |
---|---|
date | Wed, 12 Apr 2006 09:59:40 +0000 |
parents | d397ea0a79f5 |
children | 4f26f623a8bc |
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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 <cmath> float Pitch::getFrequencyForPitch(int midiPitch, float centsOffset, float concertA) { 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) { 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; } 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) { float centsOffset = 0.0; int midiPitch = getPitchForFrequency(frequency, ¢sOffset, concertA); return getPitchLabel(midiPitch, centsOffset, useFlats); }