source: python/lib/aubio/midiconv.py @ fe738f1

feature/autosinkfeature/cnnfeature/cnn_orgfeature/constantqfeature/crepefeature/crepe_orgfeature/pitchshiftfeature/pydocstringsfeature/timestretchfix/ffmpeg5pitchshiftsamplertimestretchyinfft+
Last change on this file since fe738f1 was 744190f, checked in by Paul Brossier <piem@piem.org>, 8 years ago

python/lib/aubio/slicing.py: fix samplerate

  • Property mode set to 100644
File size: 2.5 KB
Line 
1# -*- coding: utf-8 -*-
2""" utilities to convert midi note number to and from note names """
3
4__all__ = ['note2midi', 'midi2note', 'freq2note']
5
6import sys
7py3 = sys.version_info[0] == 3
8if py3:
9    str_instances = str
10    int_instances = int
11else:
12    str_instances = (str, unicode)
13    int_instances = (int, long)
14
15def note2midi(note):
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,
19                        'b': -1, u'♭': -1, u'\ufffd': -2}
20    _valid_octaves = range(-1, 10)
21    if not isinstance(note, str_instances):
22        raise TypeError("a string is required, got %s (%s)" % (note, str(type(note))))
23    if len(note) not in range(2, 5):
24        raise ValueError("string of 2 to 4 characters expected, got %d (%s)" \
25                         % (len(note), note))
26    notename, modifier, octave = [None]*3
27
28    if len(note) == 4:
29        notename, modifier, octave_sign, octave = note
30        octave = octave_sign + octave
31    elif len(note) == 3:
32        notename, modifier, octave = note
33        if modifier == '-':
34            octave = modifier + octave
35            modifier = None
36    else:
37        notename, octave = note
38
39    notename = notename.upper()
40    octave = int(octave)
41
42    if notename not in _valid_notenames:
43        raise ValueError("%s is not a valid note name" % notename)
44    if modifier not in _valid_modifiers:
45        raise ValueError("%s is not a valid modifier" % modifier)
46    if octave not in _valid_octaves:
47        raise ValueError("%s is not a valid octave" % octave)
48
49    midi = 12 + octave * 12 + _valid_notenames[notename] + _valid_modifiers[modifier]
50    if midi > 127:
51        raise ValueError("%s is outside of the range C-2 to G8" % note)
52    return midi
53
54def midi2note(midi):
55    " convert midi note number to note name, e.g. [0, 127] -> [C-1, G9] "
56    if not isinstance(midi, int_instances):
57        raise TypeError("an integer is required, got %s" % midi)
58    if midi not in range(0, 128):
59        raise ValueError("an integer between 0 and 127 is excepted, got %d" % midi)
60    _valid_notenames = ['C', 'C#', 'D', 'D#', 'E', 'F', 'F#', 'G', 'G#', 'A', 'A#', 'B']
61    return _valid_notenames[midi % 12] + str(int(midi / 12) - 1)
62
63def freq2note(freq):
64    " convert frequency in Hz to nearest note name, e.g. [0, 22050.] -> [C-1, G9] "
65    from aubio import freqtomidi
66    return midi2note(int(freqtomidi(freq)))
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