1 # -*- coding: utf-8 -*-
2 """ utilities to convert midi note number to and from note names """
4 __all__ = ['note2midi', 'midi2note', 'freq2note']
7 py3 = sys.version_info[0] == 3
12 str_instances = (str, unicode)
13 int_instances = (int, long)
16 " convert note name to midi note number, e.g. [C-1, G9] -> [0, 127] "
17 _valid_notenames = {'C': 0, 'D': 2, 'E': 4, 'F': 5, 'G': 7, 'A': 9, 'B': 11}
18 _valid_modifiers = {None: 0, u'♮': 0, '#': +1, u'♯': +1, u'\udd2a': +2,
20 'b': -1, u'♭': -1, u'\ufffd': -2,
23 _valid_octaves = range(-1, 10)
24 if not isinstance(note, str_instances):
25 raise TypeError("a string is required, got %s (%s)" % (note, str(type(note))))
26 if len(note) not in range(2, 5):
27 raise ValueError("string of 2 to 4 characters expected, got %d (%s)" \
29 notename, modifier, octave = [None]*3
32 notename, modifier, octave_sign, octave = note
33 octave = octave_sign + octave
35 notename, modifier, octave = note
37 octave = modifier + octave
40 notename, octave = note
42 notename = notename.upper()
45 if notename not in _valid_notenames:
46 raise ValueError("%s is not a valid note name" % notename)
47 if modifier not in _valid_modifiers:
48 raise ValueError("%s is not a valid modifier" % modifier)
49 if octave not in _valid_octaves:
50 raise ValueError("%s is not a valid octave" % octave)
52 midi = 12 + octave * 12 + _valid_notenames[notename] + _valid_modifiers[modifier]
54 raise ValueError("%s is outside of the range C-2 to G8" % note)
58 " convert midi note number to note name, e.g. [0, 127] -> [C-1, G9] "
59 if not isinstance(midi, int_instances):
60 raise TypeError("an integer is required, got %s" % midi)
61 if midi not in range(0, 128):
62 raise ValueError("an integer between 0 and 127 is excepted, got %d" % midi)
63 _valid_notenames = ['C', 'C#', 'D', 'D#', 'E', 'F', 'F#', 'G', 'G#', 'A', 'A#', 'B']
64 return _valid_notenames[midi % 12] + str(int(midi / 12) - 1)
67 " convert frequency in Hz to nearest note name, e.g. [0, 22050.] -> [C-1, G9] "
68 from aubio import freqtomidi
69 return midi2note(int(freqtomidi(freq)))