Mercurial > hg > svcore
view base/Pitch.h @ 427:72ec275e458b
* Basic implementation of add and remove point in data editor
* Improve resilience of frame - real-time - frame round-trip conversions
author | Chris Cannam |
---|---|
date | Mon, 16 Jun 2008 14:48:42 +0000 |
parents | 0a44caddd9fe |
children | 451f7f3ab6e7 |
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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. */ #ifndef _PITCH_H_ #define _PITCH_H_ #include <QString> class Pitch { public: /** * Return the frequency at the given MIDI pitch plus centsOffset * cents (1/100ths of a semitone). centsOffset does not have to * be in any particular range or sign. * * If concertA is non-zero, use that as the reference frequency * for the A at MIDI pitch 69; otherwise use the tuning frequency * specified in the application preferences (default 440Hz). */ static float getFrequencyForPitch(int midiPitch, float centsOffset = 0, float concertA = 0.0); /** * Return the nearest MIDI pitch to the given frequency. * * If centsOffsetReturn is non-NULL, return in *centsOffsetReturn * the number of cents (1/100ths of a semitone) difference between * the given frequency and that of the returned MIDI pitch. The * cents offset will be in the range [-50,50). * * If concertA is non-zero, use that as the reference frequency * for the A at MIDI pitch 69; otherwise use the tuning frequency * specified in the application preferences (default 440Hz). */ static int getPitchForFrequency(float frequency, float *centsOffsetReturn = 0, float concertA = 0.0); /** * Return the nearest MIDI pitch range to the given frequency * range, that is, the difference in MIDI pitch values between the * higher and lower frequencies. * * If centsOffsetReturn is non-NULL, return in *centsOffsetReturn * the number of cents (1/100ths of a semitone) difference between * the given frequency difference and the returned MIDI pitch * range. The cents offset will be in the range [-50,50). * * If concertA is non-zero, use that as the reference frequency * for the A at MIDI pitch 69; otherwise use the tuning frequency * specified in the application preferences (default 440Hz). */ static int getPitchForFrequencyDifference(float frequencyA, float frequencyB, float *centsOffsetReturn = 0, float concertA = 0.0); /** * Return a string describing the given MIDI pitch, with optional * cents offset. This consists of the note name, octave number * (with MIDI pitch 0 having octave number -2), and optional * cents. * * For example, "A#3" (A# in octave 3) or "C2-12c" (C in octave 2, * minus 12 cents). * * If useFlats is true, spell notes with flats instead of sharps, * e.g. Bb3 instead of A#3. */ static QString getPitchLabel(int midiPitch, float centsOffset = 0, bool useFlats = false); /** * Return a string describing the nearest MIDI pitch to the given * frequency, with cents offset. * * If concertA is non-zero, use that as the reference frequency * for the A at MIDI pitch 69; otherwise use the tuning frequency * specified in the application preferences (default 440Hz). * * If useFlats is true, spell notes with flats instead of sharps, * e.g. Bb3 instead of A#3. */ static QString getPitchLabelForFrequency(float frequency, float concertA = 0.0, bool useFlats = false); /** * Return a string describing the given pitch range in octaves, * semitones and cents. This is in the form e.g. "1'2+4c". */ static QString getLabelForPitchRange(int semis, float cents = 0); /** * Return true if the given frequency falls within the range of * MIDI note pitches, plus or minus half a semitone. This is * equivalent to testing whether getPitchForFrequency returns a * pitch in the MIDI range (0 to 127 inclusive) with any cents * offset. * * If concertA is non-zero, use that as the reference frequency * for the A at MIDI pitch 69; otherwise use the tuning frequency * specified in the application preferences (default 440Hz). */ static bool isFrequencyInMidiRange(float frequency, float concertA = 0.0); }; #endif